bromochloroacetic-acid and Body-Weight

Proton therapy allows to avoid excess radiation dose on normal tissues. However, there are some limitations. Indeed, passive delivery of proton beams results in an increase in the lateral dose upstream of the tumor and active scanning leads to strong differences in dose delivery. This study aims to assess possible differences in the transcriptomic response of skin in C57BL/6 mice after TBI irradiation by active or passive proton beams at the dose of 6 Gy compared to unirradiated mice. In that purpose, total RNA was extracted from skin samples 3 months after irradiation and RNA-Seq was performed. Results showed that active and passive delivery lead to completely different transcription profiles. Indeed, 140 and 167 genes were differentially expressed after active and passive scanning compared to unirradiated, respectively, with only one common gene corresponding to RIKEN cDNA 9930021J03. Moreover, protein-protein interactions performed by STRING analysis showed that 31 and 25 genes are functionally related after active and passive delivery, respectively, with no common gene between both types of proton delivery. Analysis showed that active scanning led to the regulation of genes involved in skin development which was not the case with passive delivery. Moreover, 14 ncRNA were differentially regulated after active scanning against none for passive delivery. Active scanning led to 49 potential mRNA-ncRNA pairs with one ncRNA mainly involved, Gm44383 which is a miRNA. The 43 genes potentially regulated by the miRNA Gm44393 confirmed an important role of active scanning on skin keratin pathway. Our results demonstrated that there are differences in skin gene expression still 3 months after proton irradiation versus unirradiated mouse skin. And strong differences do exist in late skin gene expression between scattered or scanned proton beams. Further investigations are strongly needed to understand this discrepancy and to improve treatments by proton therapy.

Topics: Animals; Body Weight; Dose-Response Relationship, Radiation; Gene Expression Profiling; Gene Expression Regulation; Gene Ontology; Keratins; Mice, Inbred C57BL; Protein Interaction Maps; Protons; RNA, Messenger; RNA, Untranslated; Skin; Transcriptome; Whole-Body Irradiation

The keratin-associated proteins (KAPs) are structural components of wool fibers and variation in the genes encoding the KAPs can affect wool traits. In this study, sequence variation in the ovine KAP7-1 gene (KRTAP7-1) was investigated in 222 sheep across 5 different Pakistani breeds and breed crosses. Two previously identified variants (A and B) of the KRTAP7-1 coding sequence were identified. The frequency of the genotypes AA and AB was 76% and 23%, respectively, and that of BB was 1%. The association of sequence variation with various wool traits and measurements included yield (the proportion of greasy fleece weight that is clean fleece), mean staple length (MSL), wool bulk, mean fiber diameter, fiber diameter SD, the coefficient of variation of fiber diameter, medullation, the SD of medullation, the coefficient of variation of medullation, fiber opacity, the SD of opacity, and the coefficient of variation of opacity. Variation in KRTAP7-1 was found to be associated with yield (P = 0.017). The adjusted mean yield of sheep of genotype AA (n = 169) was 79.9 ± 2.72%, while that of genotype AB (n = 51) was 81.9 ± 3.37%. There was also an association between variation in KRTAP7-1 and MSL (P = 0.024), with sheep of genotype AA (n = 169) having an adjusted mean MSL of 47.3 ± 0.57 mm compared with sheep of genotype AB (n = 51, 50.9 ± 0.65 mm). Yield and MSL are both important wool production traits, hence variation in KRTAP7-1 needs to be further investigated in more sheep of differing breed.

Topics: Animals; Body Weight; Breeding; Genotype; Keratins; Keratins, Hair-Specific; Phenotype; Polymorphism, Genetic; Sheep; Wool

The lungs and skin are important respiratory organs in Anura, but the pulmonary structure of amphibians remains unclear due to the lack of a suitable procedure. This study improved the procedure used for fixing lungs tissues and used light microscopy, transmission electron microscopy and scanning electron microscopy to reveal the differences in the lung and skin morphologies between Pelophylax nigromaculatus (P. nigromaculatus) and Bufo gargarizans (B. gargarizans). In P. nigromaculatus and B. gargarizans, the cystic lungs comprise a continuous outer pulmonary wall on which primary, secondary, and tertiary septa attach, and a number of regular lattices form from raised capillaries and the pulmonary epithelium on the surfaces of the pulmonary wall and septa. Each lattice in P. nigromaculatus consists of several elliptical sheets and flat bottom, and the septa are distributed with denser sheets and have a larger stretching range than the pulmonary wall. The lattice in B. gargarizans consists of thick folds and an uneven bottom with several thin folds, and the septa have more developed thick and thin folds than the pulmonary wall. However, the density of the pulmonary microvilli, the area of a single capillary, the thicknesses of the blood-air barrier, pulmonary wall and septum, and the lung/body weight percentage obtained for B. gargarizans were higher than those found for P. nigromaculatus. In P. nigromaculatus, the dorsal skin has dense capillaries and a ring surface structure with mucus layer on the stratum corneum, and the ventral skin is slightly keratinized. In B. gargarizans, the stratum corneum in both the dorsal and ventral skins is completely keratinized. A fine ultrastructure analysis of P. nigromaculatus and B. gargarizans revealed that the pulmonary septa are more developed than the pulmonary walls, which means that the septa have a stronger respiratory function. The more developed lungs are helpful for the adaptation of B. gargarizans to drought environments, whereas P. nigromaculatus has to rely on more vigorous skin respiration to adapt to a humid environment.

Topics: Animals; Body Weight; Bufonidae; Capillaries; Epidermis; Epithelium; Image Processing, Computer-Assisted; Keratins; Lung; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Ranidae; Skin; Species Specificity

Heat stress and fescue toxicosis caused by ingesting tall fescue infected with the endophytic fungus Epichloë coenophiala represent two of the most prevalent stressors to beef cattle in the United States and cost the beef industry millions of dollars each year. The rate at which a beef cow sheds her winter coat early in the summer is an indicator of adaptation to heat and an economically relevant trait in temperate or subtropical parts of the world. Furthermore, research suggests that early-summer hair shedding may reflect tolerance to fescue toxicosis, since vasoconstriction induced by fescue toxicosis limits the ability of an animal to shed its winter coat. Both heat stress and fescue toxicosis reduce profitability partly via indirect maternal effects on calf weaning weight. Here, we developed parameters for routine genetic evaluation of hair shedding score in American Angus cattle, and identified genomic loci associated with variation in hair shedding score via genome-wide association analysis (GWAA).. Hair shedding score was moderately heritable (h. This work contributes to a continuing trend in the development of genetic evaluations for environmental adaptation. Our results will aid beef cattle producers in selecting more sustainable and climate-adapted cattle, as well as enable the development of similar routine genetic evaluations in other breeds.

Topics: Animal Fur; Animals; Body Weight; Breeding; Cattle; Cattle Diseases; Disease Susceptibility; Epichloe; Keratins; Mycotoxicosis; Polymorphism, Single Nucleotide; Prolactin; Quantitative Trait, Heritable; Thermotolerance; Weaning

Pharmacological therapy of osteoporosis reduces bone loss and risk of fracture in patients. Modulation of bone mineral density cannot explain all effects. Other aspects of bone quality affecting fragility and ways to monitor them need to be better understood. Keratinous tissue acts as surrogate marker for bone protein deterioration caused by oestrogen deficiency in rats. Ovariectomised rats were treated with alendronate (ALN), parathyroid hormone (PTH) or estrogen (E2). MicroCT assessed macro structural changes. Raman spectroscopy assessed biochemical changes. Micro CT confirmed that all treatments prevented ovariectomy-induced macro structural bone loss in rats. PTH induced macro structural changes unrelated to ovariectomy. Raman analysis revealed ALN and PTH partially protect against molecular level changes to bone collagen (80% protection) and mineral (50% protection) phases. E2 failed to prevent biochemical change. The treatments induced alterations unassociated with the ovariectomy; increased beta sheet with E2, globular alpha helices with PTH and fibrous alpha helices with both ALN and PTH. ALN is closest to maintaining physiological status of the animals, while PTH (comparable protective effect) induces side effects. E2 is unable to prevent molecular level changes associated with ovariectomy. Raman spectroscopy can act as predictive tool for monitoring pharmacological therapy of osteoporosis in rodents. Keratinous tissue is a useful surrogate marker for the protein related impact of these therapies.The results demonstrate utility of surrogates where a clear systemic causation connects the surrogate to the target tissue. It demonstrates the need to assess broader biomolecular impact of interventions to examine side effects.

Topics: Alendronate; Animals; Body Weight; Bone Density; Bone Density Conservation Agents; Disease Models, Animal; Estrogens; Female; Humans; Keratins; Osteoporosis, Postmenopausal; Parathyroid Hormone; Rats; Rats, Sprague-Dawley; Spectrum Analysis, Raman; X-Ray Microtomography

The increased incidence of solar ultraviolet (UV) radiation, an environmental genotoxic agent, due to ozone depletion or deforestation may help to explain the enigmatic decline of amphibian populations in specific localities. In this work, we evaluated the importance of DNA repair performed by photolyases to maintain the performance of treefrog tadpoles after acute and chronic treatments with environmental-simulated doses of solar UVB and UVA radiation. Immediately after UV treatments, tadpoles were exposed to a visible light source to activate photolyases or kept in dark containers. The biological effects of UV treatments were evaluated through morphological, histological, locomotor and survival analyzes of Boana pulchella tadpoles (Anura: Hylidae). The results indicate that tadpole body weight suffered influence after both UVB and UVA treatments, although the body length was bit affected. The locomotor performance of UVB-exposed tadpoles was significantly reduced. In addition, UVB radiation induced a severe impact on tadpole skin, as well as on keratinized structures of mouth (tooth rows and jaw), indicating that these should be important effects of solar UV radiation in the reduction of tadpole performance. Furthermore, photolyases activation was fundamental for the maintenance of tadpole performance after chronic UVB exposures, but it was relatively inefficient after acute exposures to UVB, but not to UVA radiation. Therefore, this work demonstrates how the UV-induced genotoxicity and structural alterations in the skin and oral apparatus affect tadpole performance and survival.

Topics: Animals; Body Weight; DNA Damage; DNA Repair; Keratins; Larva; Locomotion; Mouth; Skin; Ultraviolet Rays

Ketamine is used clinically for anesthesia but is also abused as a recreational drug. Previously, it has been established that ketamine‑induced bladder interstitial cystitis is a common syndrome in ketamine‑abusing individuals. As the mechanisms underlying ketamine‑induced cystitis have yet to be revealed, the present study investigated the effect of ketamine on human urothelial cell lines and utilized a ketamine‑injected mouse model to identify ketamine‑induced changes in gene expression in mice bladders. In the in vitro bladder cell line assay, ketamine induced cytotoxicity in a dose‑ and time‑dependent manner. Ketamine arrested the cells in G1 phase and increased the sub‑G1 population, and also increased the barrier permeability of these cell lines. In the ketamine‑injected mouse model, ketamine did not change the body weight and bladder histology of the animals at the dose of 30 mg/kg/day for 60 days. Global gene expression analysis of the animals' bladders following data screening identified ten upregulated genes and 36 downregulated genes induced by ketamine. A total of 52% of keratin family genes were downregulated, particularly keratin 6a, 13 and 14, which was confirmed by polymerase chain reaction analysis. Keratin 14 protein, one of the 36 ketamine‑induced downregulated genes, was also reduced in the ketamine‑treated mouse bladder, as determined by immunohistochemical analysis. This suggested that cytotoxicity and keratin gene downregulation may have a critical role in ketamine‑induced cystitis.

Topics: Analgesics; Animals; Body Weight; Cell Line; Cell Survival; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation; Humans; Immunohistochemistry; Keratins; Ketamine; Male; Mice; Mice, Inbred BALB C; Permeability; Urinary Bladder

Sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor-based incretin therapy intended for the treatment of type 2 diabetes mellitus (T2DM), has not been linked to adverse effects on the pancreas in prospective clinical trials or in nonclinical toxicology studies. To further assess potential pancreatic effects, sitagliptin was studied in the male Zucker diabetic fatty (ZDF) rat model of T2DM. Following 3 months of oral dosing with vehicle, or sitagliptin at doses 3- to 19-fold above the clinically therapeutic plasma concentration, which increased active plasma glucagon-like peptide-1 levels up to approximately 3-fold, or following 3 months of oral dosing with metformin, a non-incretin-based reference T2DM treatment, the pancreas of male ZDF rats was evaluated using qualitative and quantitative histopathology techniques. In the quantitative evaluation, proliferative index was calculated in exocrine pancreatic ducts and ductules using computer-based image analysis on sections stained by immunohistochemistry for cytokeratin (a cytoplasmic epithelial cell marker) and Ki-67 (a nuclear marker of recent cell division). Relative to controls, sitagliptin treatment did not alter disease progression based on detailed clinical signs and clinical pathology assessments. Sitagliptin treatment did not result in pancreatitis or any adverse effect on the pancreas based on a qualitative histopathology evaluation. Proliferative index did not increase with sitagliptin treatment based on quantitative assessment of more than 5000 sections of pancreas, where control group means ranged from 0.698-0.845% and sitagliptin-treated group means ranged from 0.679-0.701% (P = .874). Metformin treatment was similarly evaluated and found not to have adverse effects on pancreas.

Topics: Administration, Oral; Animals; Blood Glucose; Body Weight; Cell Proliferation; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Hypoglycemic Agents; Keratins; Ki-67 Antigen; Male; Metformin; Pancreas, Exocrine; Pyrazines; Rats; Rats, Zucker; Sitagliptin Phosphate; Triazoles

The worldwide-industrialized production of Atlantic salmon (Salmo salar) has increased dramatically during the last decades, followed by diseases related to the on-going domestication process as a growing concern. Even though the gastrointestinal tract seems to be a target for different disorders in farmed fish, a description of the normal intestinal status in healthy, wild salmon is warranted. Here, we provide such information in addition to suggesting a referable anatomical standardization for the intestine. In this study, two groups of wild Atlantic salmon were investigated, consisting of post smolts on feed caught in the sea and of sexually mature, starved individuals sampled from a river. The two groups represent different stages in the anadromous salmon life cycle, which also are part of the production cycle of farmed salmon. Selected regions of gastrointestinal tract were subjected to morphological investigations including immunohistochemical, scanning electron microscopic, and morphometric analyses. A morphology-based nomenclature was established, defining the cardiac part of the stomach and five different regions of the Atlantic salmon intestine, including pyloric caeca, first segment of the mid-intestine with pyloric caeca, first segment of the mid-intestine posterior to pyloric caeca, second segment of the mid-intestine and posterior intestinal segment. In each of the above described regions, for both groups of fish, morphometrical measurements and regional histological investigations were performed with regards to magnitude and direction of mucosal folding as well as the composition of the intestinal wall. Additionally, immunohistochemistry showing cells positive for cytokeratins, α-actin and proliferating cell nuclear antigen, in addition to alkaline phosphatase reactivity in the segments is presented.

Topics: Actins; Animals; Body Weight; Cell Differentiation; Cell Proliferation; Female; Gastrointestinal Tract; Immunohistochemistry; Intestinal Mucosa; Intestines; Keratins; Salmo salar; Stomach

The formation of protein inclusions is frequently associated with chronic metabolic diseases. In mice, short-term intoxication with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) leads to hepatocellular damage indicated by elevated serum liver enzyme activities, whereas only minor morphological changes are observed. Conversely, chronic administration of DDC for several weeks results in severe morphological damage, characterized by hepatocellular ballooning, disruption of the intermediate filament cytoskeleton, and formation of Mallory-Denk bodies consisting predominantly of misfolded keratins, Sqstm1/p62, and heat shock proteins. To evaluate the mechanistic underpinnings for this dichotomy we dissected the time-course of DDC intoxication for up to 10 weeks. We determined body weight change, serum liver enzyme activities, morphologic alterations, induction of antioxidant response (heme oxygenase-1, HO-1), oxidative damage and ATP content in livers as well as respiration, oxidative damage and the presence and activity of HO-1 in endoplasmic reticulum and mitochondria (mtHO-1). Elevated serum liver enzyme activity and oxidative liver damage were already present at early intoxication stages without further subsequent increase. After 2 weeks of intoxication, mice had transiently lost 9% of their body weight, liver ATP-content was reduced to 58% of controls, succinate-driven respiration was uncoupled from ATP-production and antioxidant response was associated with the appearance of catalytically active mtHO-1. Oxidative damage was associated with both acute and chronic DDC toxicity whereas the onset of chronic intoxication was specifically associated with mitochondrial dysfunction which was maximal after 2 weeks of intoxication. At this transition stage, adaptive responses involving mtHO-1 were induced, indirectly leading to improved respiration and preventing further drop of ATP levels. Our observations clearly demonstrate principally different mechanisms for acute and chronic toxic damage.

Topics: Acute Disease; Adaptor Proteins, Signal Transducing; Adenosine Triphosphate; Animals; Body Weight; Chemical and Drug Induced Liver Injury; Chemical and Drug Induced Liver Injury, Chronic; Energy Metabolism; Enzyme Induction; Gene Expression; Heat-Shock Proteins; Heme Oxygenase-1; Hepatocytes; Keratins; Liver; Male; Mallory Bodies; Mice; Mitochondria; Oxidative Stress; Protein Folding; Pyridines; Sequestosome-1 Protein; Time Factors

To study the chronological appearance of pancreatic islet neogenesis-associated protein (INGAP)-positive cells and its correlation with the increase in β-cell mass and function in fetal and neonatal rats.. Normal Wistar rat embryos (E) at gestational days 15, 17, and 19 (E15, E17, E19) and 7-day-old postnatal rats (P7) were humanely killed to determine body and pancreas weight; blood glucose; glucose and arginine-induced insulin secretion; real-time polymerase chain reaction of Pdx1 and Ngn3; quantitative immunomorphometric analysis of β-cell replication and apoptosis rate, cytokeratin and INGAP cell mass, and Pdx-1- and Ngn3-positive cells.. Body and pancreas weight increased with age (P7 > E19 > E17 > E15; P < 0.05). Neonates had higher blood glucose concentrations than embryos (P < 0.05). We recorded a simultaneous and significant age-dependent trend of increase in the number of β- and Pdx-1-positive cells, β- and cytokeratin-positive cell mass and β-cell capacity to release insulin in response to glucose and arginine, and decreased β-cell apoptotic rate. These changes closely paralleled the increase in INGAP-positive cell mass.. These findings suggest that INGAP exerts a positive modulatory effect on β-cell mass and its secretory function in fetal and neonatal rats, thus becoming a new component in the multifactorial regulation of such processes.

Topics: Animals; Animals, Newborn; Antigens, Neoplasm; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Biomarkers, Tumor; Body Weight; Cell Count; Female; Gene Expression Regulation, Developmental; Homeodomain Proteins; Immunohistochemistry; Insulin; Insulin Secretion; Insulin-Secreting Cells; Islets of Langerhans; Keratins; Lectins, C-Type; Male; Morphogenesis; Nerve Tissue Proteins; Organ Size; Pancreatitis-Associated Proteins; Pregnancy; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Trans-Activators

Suboptimal intake of Zn is one of the most common nutritional problems worldwide. Previously, we have shown that Zn deficiency (ZD) produces oxidative and nitrosative stress in the lung of rats. We analyse the effect of moderate ZD on the expression of several intermediate filaments of the cytoskeleton, as well as the effect of restoring Zn during the refeeding period. Adult male rats were divided into three groups: Zn-adequate control (CO) group; ZD group; Zn-refeeding group. CerbB-2 and proliferating cell nuclear antigen (PCNA) expression was increased in the ZD group while the other parameters did not change. During the refeeding time, CerbB-2, cytokeratins, vimentin and PCNA immunostaining was higher than that in the CO group. The present findings indicate that the overexpression of some markers could lead to the fibrotic process in the lung. Perhaps ZD implications must be taken into account in health interventions because an inflammation environment is associated with ZD in the lung.

Topics: Animals; Biomarkers; Body Weight; Cadherins; Extracellular Matrix; Gene Expression Regulation; Immunohistochemistry; Keratins; Lung; Male; Rats; Receptor, ErbB-2; Transforming Growth Factor beta1; Zinc

The particular combination of polydeoxyribonucleotides, l-carnitine, calcium ions, proteolytic enzyme and other ingredients acts in a synergetic way in the regeneration of skin and connective tissues. This new formulation of active principles was tested in vitro as a cell and tissue culture medium and in vivo for various preparations in support of tissue regeneration. In vitro, the new blend allowed the maintenance of skin biopsies for more than 1 year in eutrophic conditions. Immunocytochemical analyses of fibroblasts isolated from these biopsies confirmed a significant increase of the epidermal and connective wound-healing markers such as collagen type I, collagen type IV, cytokeratin 1 (CK1), CK5, CK10 and CK14 versus controls. To examine the effects of the new compound in vivo, we studied impaired wound healing in genetically diabetic db/db mice. At day 18, diabetic mice treated with the new composition showed 100% closure of wounds and faster healing than mice treated with the other solutions. This complex of vital continuity factors or life-keeping factors could be used as a tissue-preserving solution or a cosmetic/drug/medical device to accelerate wound healing in the treatment of patients with deficient wound repair to promote the regeneration of cutaneous and connective tissues (injuries-wound, dermatitis) and prevent the recurrent relapses.

Topics: Administration, Topical; Animals; Biopsy; Body Weight; Cell Survival; Cells, Cultured; Chemistry, Pharmaceutical; Collagen Type I; Collagen Type II; Connective Tissue; Culture Media; Diabetes Mellitus; Fibroblasts; Humans; Immunohistochemistry; Keratins; Male; Mice; Polydeoxyribonucleotides; Skin; Staining and Labeling; Wound Healing

Bromochloroacetic acid occurs as a by-product of water disinfection. We studied the effects of bromochloroacetic acid in drinking water on male and female rats and mice to identify potential toxic or cancer-related hazards.. We gave drinking water containing 250, 500, or 1,000 mg of bromochloroacetic acid per liter of water to groups of 50 male and female rats and mice for 2 years. Control animals received the same tap water with no chemical added. At the end of the study tissues from more than 40 sites were examined for every animal.. Survival was similar for rats and female mice receiving bromochloroacetic acid and the controls; survival of 1,000 mg/L male mice was less. Male rats receiving bromochloroacetic acid had increased rates of malignant mesotheliomas. Adenomas of the large intestine were seen in both male and female rats receiving the highest concentration of bromochloroacetic acid. Exposed female rats also had increased incidences of multiple fibroadenomas of the mammary gland. Slightly increased incidences of liver hepatocellular adenomas in male and female rats and pancreatic islet adenomas in male rats were also observed in exposed animals. Male and female mice exposed to bromochloroacetic acid had increased rates of a variety of liver cancers.. We conclude that bromochloroacetic acid in the drinking water caused mesothelioma in male rats, multiple fibroadenomas of the mammary gland in female rats, and adenomas of the large intestine in both male and female rats. Adenomas of the liver in male and female rats and of the pancreatic islets in male rats may also have been related to bromochloroacetic acid exposure. We conclude that bromochloroacetic acid caused liver cancer in male and female mice.

Topics: Acetates; Animals; Body Weight; Carcinogenicity Tests; Dose-Response Relationship, Drug; Drinking; Female; Male; Mice; Mice, Inbred Strains; Neoplasms, Experimental; Rats; Rats, Inbred F344

The present study was conducted to examine the effect of administration of conophylline (CnP) and betacellulindelta4 (BTCdelta4) on the beta-cell mass in neonatal streptozotocin-treated rats (neonatal STZ rats). STZ (100 microg/g) was injected into neonatal rats, and then CnP (2 microg/g) and/or BTCdelta4 (200 pmol/g) were administered to neonatal STZ rats for 1 week. The plasma glucose concentration was monitored, and an intraperitoneal glucose tolerance test (ipGTT) was performed on day 8 and at 8 weeks after the STZ injection. In neonatal STZ rats treated with control solution (S group), the plasma glucose concentration increased for several days after the STZ injection, returned to nearly normal levels, and then increased gradually after six weeks of age. Eight weeks after the STZ-injection, the plasma glucose concentration was increased significantly compared to that of normal rats. The glucose response to ipGTT was significantly reduced in neonatal STZ rats treated with CnP (CnP group), BTCdelta4 (delta4 group) and CnP+BTCdelta4 (CnP+delta4 group). The beta-cell mass and the insulin content of the pancreas were significantly increased in the CnP group and delta4 group. The effect of CnP+delta4 was greater than that of CnP alone or BTCdelta4 alone. CnP+BTCdelta4 significantly increased the number of PDX-1-positive ductal cells and the number of insulin/BrdU double-positive ductal cells. These results indicate the efficacy of CnP and BTCdelta4 in increasing the beta-cells mass of neonatal STZ-treated rats.

Topics: Aging; Animals; Animals, Newborn; Area Under Curve; Betacellulin; Blood Glucose; Body Weight; Cell Differentiation; Diabetes Mellitus, Experimental; Glucose; Glucose Intolerance; Homeodomain Proteins; Insulin; Insulin-Secreting Cells; Intercellular Signaling Peptides and Proteins; Keratins; Organ Size; Pancreas; Random Allocation; Rats; Rats, Wistar; Time Factors; Trans-Activators; Vinca Alkaloids

The objective of this study was to ascertain whether sequential sampling and isotopic analysis of bovine hooves could be used to reconstruct the dietary history of cattle. A controlled, on-farm experiment was conducted in which cattle were switched from a barley-based diet to an isotopically different diet incorporating maize, urea and seaweed (the isotopic spacing between diets was 13.6 per thousand for delta(13)C and 8.0 per thousand for delta(15)N) and maintained on that diet for 168 days. Postmortem sampling of the cleaned anterior wall of the lateral, left front claw was carried out on five individuals using a micro-drilling technique. From the first 60 mm of each claw, up to 41 samples with a spacing between them of less than 1 mm were collected. Bands were less than 1 mm deep and had a mean width of 1.2 mm. The hoof keratin showed a rapid increase followed by a slower increase in its delta(13)C and delta(15)N values following the diet switch, suggesting that C and N in hoof keratin originate from more than one pool. However, the response of the N isotope composition of the hoof was somewhat delayed compared with that of C. Estimated mean hoof growth rates for these cattle were 10.5 +/- 2.3 mm per month and 6.7 +/- 1.0 mm per month (+/-SD, n = 5) when receiving the barley-based transition diet and the maize-based experimental diet, respectively. These values are considerably higher than previous estimates obtained by visual methods and they suggest that diet may have a greater influence on hoof growth rates than seasonality. These results demonstrate that hooves are a suitable incremental tissue for high-resolution isotopic reconstruction of the dietary history of bovine animals.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Body Weight; Carbon Isotopes; Cattle; Diet; Hoof and Claw; Hordeum; Isotopes; Keratins; Male; Nitrogen Isotopes; Seaweed; Urea; Zea mays

Studies of mammalian pigmentation have identified many genes involved in the development, migration, and function of melanocytes. Molecular and biochemical mechanisms that switch melanocytes between the production of eumelanin or pheomelanin involve the opposing action of two signaling molecules, alpha-Melanocyte Stimulating Hormone (alphaMSH) and Agouti Signal Protein (ASP). AlphaMSH affects various aspects of melanocyte behavior, stimulating melanocyte dendricity, attachment to extracellular matrix proteins, but also up-regulating the expression of eumelanogenic genes. In response to ASP, melanocytes switch from producing eumelanin to pheomelanin concomitant with the down-regulation of melanogenic genes transcription. Since activation of signaling pathways leads to mRNA expression, microarray technology can provide a quantitative assessment of the consequences of this activation. Significant up/down regulation of all known melanogenic genes by alphaMSH/ASP in cultured melanocytes has been previously reported. We have now used the cDNA microarray technique to screen alphaMSH-treated melanocytes to identify genes that are transcriptionally enhanced by this factor. We report the melanocytic expression and alphaMSH up-regulation of 11 genes spanning 7 functional categories such as apoptosis, body weight control, intracellular transport, signal transduction, oncogenic transformation, transcription factors and genes coding for keratin associated proteins.

Topics: Agouti Signaling Protein; alpha-MSH; Animals; Apoptosis; Biological Transport; Body Weight; Cells, Cultured; Gene Expression Regulation; Intercellular Signaling Peptides and Proteins; Keratins; Melanins; Melanocytes; Mice; Mice, Inbred C57BL; Oligonucleotide Array Sequence Analysis; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Transcription Factors; Transcription, Genetic

The epidermis has a great potential as a bioreactor to produce proteins with systemic action. However, the consequences of ectopic epidermal protein overexpression need to be carefully addressed to avoid both local and systemic adverse effects. Thus, the long-term effects of leptin on skin physiology have not been studied, and the metabolic consequences of sustained keratinocyte-derived leptin overexpression are unknown. Herein we describe that very high serum leptin levels can be achieved from a cutaneous source in transgenic mice in which leptin cDNA overexpression was driven by the keratin K5 gene regulatory sequences. Histopathological analysis including the study of skin differentiation and proliferation markers in these transgenic mice revealed that keratinocyte-derived leptin overexpression appears not to have any impact on cutaneous homeostasis. Although young K5-leptin transgenic mice showed remarkable thinness and high glucose metabolism as shown in other leptin transgenic mouse models, a marked leptin insensitivity become apparent as early as 3-4 months of age as demonstrated by increased weight gain and insulin resistance development. Other signs of leptin/insulin resistance included increased bone mass, organomegaly, and wound healing impairment. In addition, to provide evidence for the lack of untoward effects of leptin on epidermis, this transgenic mouse helps us to establish the safe ranges of keratinocyte-derived leptin overexpression and may be useful as a model to study leptin resistance.

Topics: Adipose Tissue; Animals; Animals, Newborn; Body Weight; Cell Differentiation; Drug Resistance; Energy Intake; Epidermal Cells; Epidermis; Keratin-15; Keratin-5; Keratinocytes; Keratins; Leptin; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Transgenic; Skin; Wound Healing

Increasing beta-cell mass and/or function could restore glucose homeostasis in diabetes mellitus. Hitherto, trophic factors for beta-cell regeneration after toxic events have been difficult to identify. We evaluated the application of gastrin and epidermal growth factor after alloxan-induced pancreatic beta-cell damage.. After alloxan treatment (70 mg/kg), mice were implanted with Alzet osmotic minipumps releasing gastrin and epidermal growth factor for one week. We monitored glycaemia, did histological analyses of the pancreata and quantified pancreatic beta-cell mass and insulin content.. Alloxan treatment alone resulted in a persisting hyperglycaemic state. Combined gastrin and epidermal growth factor treatment restored normoglycaemia in 3 days, an effect which seemed permanent. Glucose tolerance tests showed normal glucose responsiveness. Gastrin on its own and epidermal growth factor on its own did not alleviate hyperglycaemia. Islet mass, islet density and pancreatic insulin content were higher in mice treated with gastrin and epidermal growth factor than in untreated mice with persisting hyperglycaemia. In normoglycaemic control mice treatment with gastrin and epidermal growth factor did not affect these parameters. We detected transitional cytokeratin-positive ductal to endocrine insulin-expressing cells and noted increased ductal but not beta-cell proliferation.. Our results show that combined treatment with gastrin and epidermal growth factor can induce sufficient regeneration of a functional islet mass to restore glucose homeostasis.

Topics: Alloxan; Animals; Blood Glucose; Body Weight; Cell Count; Cell Division; Diabetes Mellitus, Experimental; Epidermal Growth Factor; Gastrins; Glucose Tolerance Test; Immunohistochemistry; Infusion Pumps, Implantable; Insulin; Islets of Langerhans; Keratins; Male; Mice; Mice, Inbred C57BL; Organ Size; Pancreas; Pancreatic Ducts

A single maternal dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on gestation day (GD) 13 can greatly impair ventral prostate, dorsolateral prostate, anterior prostate, and seminal vesicle development in wild-type C57BL/6 mice. The developmental stages at which these organs are most sensitive to TCDD exposure have now been investigated. Pregnant mice were dosed orally with 5 micro g TCDD/kg or vehicle on GD 13, and their pups were fostered at birth to dams of the same treatment or cross-fostered to dams of the opposite treatment. Additional males had in utero and lactational TCDD exposure following maternal dosing on GD 16. Organ weights and secretory protein, cytokeratin 8, and cyclophilin mRNA expression were determined at 35 days of age. Effects of TCDD on ventral prostate development were due primarily to in utero exposure; the critical window was between GD 13 and birth. Dorsolateral prostate development was inhibited about equally by in utero or lactational exposure, and vulnerability did not begin until GD 16. Anterior prostate development was also affected by both in utero and lactational TCDD exposure, particularly the former. Vulnerability began before GD 16 and continued into postnatal life. Seminal vesicle development was essentially unaffected by in utero or lactational exposure alone but was significantly inhibited by combined exposure, regardless of whether dams were dosed on GD 13 or 16. In summary, the time during which each organ was most vulnerable to TCDD exposure varied from one organ to another. These findings provide insights into the developmental processes that TCDD inhibits in each organ, and demonstrate that TCDD inhibits ventral prostate development before this organ first appears, presumably via effects on the urogenital sinus. The observation that in utero TCDD exposure (alone) inhibited development of each prostate lobe is significant because previous studies have shown that little TCDD is transmitted to mice before birth.

Topics: Androgen-Binding Protein; Animals; Body Weight; Environmental Pollutants; Female; Keratins; Lactation; Male; Mice; Mice, Inbred C57BL; Organ Size; Polychlorinated Dibenzodioxins; Pregnancy; Prostate; Receptors, Aryl Hydrocarbon; Seminal Vesicles

Alkaline conditions in the oral cavity may be caused by a variety of stimuli, including tobacco products, antacids, alkaline drinking water or bicarbonate toothpaste. The effects of alkaline pH on oral mucosa have not been systematically studied. To assess the systemic (organ) and local (oral mucosal) effects of alkalinity, drinking water supplemented with Ca(OH)2 or NaOH, with pH 11.2 or 12 was administered to rats (n = 36) for 52 weeks. Tissues were subjected to histopathological examination; oral mucosal biopsy samples were also subjected to immunohistochemical (IHC) analyses for pankeratin, CK19, CK5, CK4, PCNA, ICAM-1, CD44, CD68, S-100, HSP 60, HSP70, and HSP90. At completion of the study, animals in the study groups had lower body weights (up to 29% less) than controls despite equal food and water intake, suggesting a systemic response to the alkaline treatment. The lowest body weight was found in rats exposed to water with the highest pH value and starting the experiment when young (6 weeks). No histological changes attributable to alkaline exposure occurred in the oral mucosa or other tissues studied. Alkaline exposure did not affect cell proliferation in the oral epithelium, as shown by the equal expression of PCNA in groups. The up-regulation of HSP70 protein expression in the oral mucosa of rats exposed to alkaline water, especially Ca(OH)2 treated rats, may indicate a protective response. Intercellular adhesion molecule-1 (ICAM-1) positivity was lost in 6/12 rats treated with Ca(OH)2 with pH 11.2, and loss of CD44 expression was seen in 3/6 rats in both study groups exposed to alkaline water with pH 12. The results suggest that the oral mucosa in rats is resistant to the effects of highly alkaline drinking water. However, high alkalinity may have some unknown systemic effects leading to growth retardation, the cause of which remains to be determined.

Topics: Alkalies; Animals; Body Weight; Calcium Hydroxide; Female; HSP70 Heat-Shock Proteins; Hyaluronan Receptors; Hydrogen-Ion Concentration; Intercellular Adhesion Molecule-1; Keratins; Male; Mouth Mucosa; Rats; Rats, Long-Evans; Sex Factors; Sodium Hydroxide; Water

The possible relationship between changes in islet cell mass and in islet neogenesis-associated protein (INGAP)-cell mass induced by sucrose administration to normal hamsters was investigated. Normal hamsters were given sucrose (10% in drinking water) for 5 (S8) or 21 (S24) weeks and compared with control (C) fed hamsters. Serum glucose and insulin levels were measured and quantitative immunocytochemistry of the endocrine pancreas was performed. Serum glucose levels were comparable among the groups, while insulin levels were higher in S hamsters. There was a significant increase in beta-cell mass (P<0.02) and in beta-cell 5-bromo-2'-deoxyuridine index (P<0.01), and a significant decrease in islet volume (P<0.01) only in S8 vs C8 hamsters. Cytokeratin (CK)-labelled cells were detected only in S8 hamsters. INGAP-positive cell mass was significantly larger only in S8 vs C8 hamsters. Endocrine INGAP-positive cells were located at the islet periphery ( approximately 96%), spread within the exocrine pancreas ( approximately 3%), and in ductal cells (<1%) in all groups. INGAP positivity and glucagon co-localization varied according to topographic location and type of treatment. In C8 hamsters, 49.1+/-6. 9% cells were INGAP- and glucagon-positive in the islets, while this percentage decreased by almost half in endocrine extra-insular and ductal cells. In S8 animals, co-expression increased in endocrine extra-insular cells to 36.3+/-9.5%, with similar figures in the islets, decreasing to 19.7+/-6.9% in ductal cells. INGAP-positive cells located at the islet periphery also co-expressed CK. In conclusion, a significant increase of INGAP-positive cell mass was only observed at 8 weeks when neogenesis was present, suggesting that this peptide might participate in the control of islet neogenesis. Thus, INGAP could be a potentially useful tool to treat conditions in which there is a decrease in beta-cell mass.

Topics: Animals; Antigens, Neoplasm; Biomarkers, Tumor; Blood Glucose; Body Weight; Cricetinae; Drinking; Eating; Fluorescent Antibody Technique; Insulin; Islets of Langerhans; Keratins; Lectins, C-Type; Male; Pancreatitis-Associated Proteins; Proteins; Regeneration; Sucrose

Solanum glaucophyllum (Sg) (synonym S. malacoxylon) is a plant toxic to cattle due to its high levels of 1,25-dihydroxyvitamin D3 as glycoside derivatives. Sg causes a disease characterized by wasting and calcification of soft tissues. The effects of vitamin D are not only important in calcium homeostasis, but also in immune regulation, cell growth and cell differentiation. Skin samples in Sg-intoxicated and control heifers were studied histologically. Cellular differentiation and proliferation were analysed by immunohistochemical expression of cytokeratins, involucrin and proliferating cell nuclear antigen (PCNA). The results were obtained by image processing and analysis and were statistically evaluated. Sg-intoxicated cattle showed atrophy of epidermis and severe involution of hair follicles and of sebaceous and sweat glands. As judged by PCNA expression, cellular proliferation was reduced, even though the reduction was not statistically significant. The analysed markers of differentiation, e.g. involucrin and cytokeratins 10 and 11, changed in relation to Sg-poisoning. The possible pathogenesis of the skin lesions is discussed.

Topics: Animals; Antibodies, Monoclonal; Argentina; Body Weight; Cattle; Cattle Diseases; Cell Differentiation; Cell Division; Female; Image Processing, Computer-Assisted; Immunohistochemistry; Keratins; Plant Poisoning; Proliferating Cell Nuclear Antigen; Protein Precursors; Skin Diseases; Solanaceae; Solanaceous Alkaloids; Vitamin D

Human consumption of chlorinated drinking water has been linked epidemiologically to bladder, kidney, and rectal cancers. The disinfection by-product (DBP) dichloroacetic acid is a hepatocarcinogen in Fischer 344 rats and B6C3F1 mice. The objective of this study is to determine the effect of the DBPs dichloro-, bromochloro-, and dibromoacetic acids (DCA, BCA, DBA) on intestinal microbial populations and their metabolism, with emphasis on enzymes involved in the bioactivation of procarcinogens and promutagens. One-month-old male Fischer 344 rats were provided water ad libitum containing 1 g/l DCA, BCA, or DBA for up to 5 weeks. At 1, 3, and 5 weeks of treatment, beta-glucuronidase (GLR), beta-galactosidase (GAL), beta-glucosidase (GLU), nitroreductase (NR), azoreductase (AR), and dechlorinase (DC) activities were determined in cecal and small and large intestinal homogenates. After 5 weeks of treatment, intestinal populations were enumerated on selective media. Cecal GAL (DCA, BCA, DBA) and GLR (DCA, DBA) activities were reduced after 1 and 3 weeks of treatment and GAL activity was elevated at 5 weeks (BCA). Large intestinal GAL (DCA, BCA) and GLU (DCA, BCA, DBA) activities were elevated after 5 weeks of treatment. Week 5 cecal AR (DCA, BCA, DBA), NR (DCA), and DC (DCA, DBA) activities were reduced. Even though some significant changes in intestinal populations were observed, use of selective media was not sensitive enough to explain fluctuations in enzyme activity. Haloacetic acids in the drinking water alter intestinal metabolism, which could influence bioactivation of promutagens and procarcinogens in the drinking water.

Topics: Acetates; Animals; Bacteria; Body Weight; Dichloroacetic Acid; Intestines; Male; Organ Size; Rats; Rats, Inbred F344; Water Pollutants, Chemical; Water Supply

Feeding diabetes-prone BioBreeding (BBdp) rats a hydrolysed-casein (HC)-based semi-purified diet results in two-to-three-fold fewer diabetes cases compared with feeding cereal-based diets such as NIH-07 (NIH). We showed previously that young NIH-fed BBdp rats had decreased islet area at a time when classic insulitis was minimal. Rats fed an HC diet maintained near normal islet area followed 3-4 weeks later by a deviation of the pancreas cytokine pattern from Th1 to Th2/Th3. This finding raised the possibility that BBdp rats were more susceptible to diet-induced changes in islet homeostasis. To investigate this possibility further, BBdp rats were fed an NIH or HC diet from days 23 to 45. Bouin's fixed sections of pancreas were stained with H & E or antibodies for insulin and glucagon. Cell proliferation nuclear antigen (PCNA) was used as a marker of cell proliferation and cells were stained for putative markers of islet neogenesis, cytokeratin 20 (CK20) and Bcl-2. Apoptotic bodies were recognized by morphological features and by TUNEL-positive staining. BBdp rats fed an HC diet had a significantly higher beta-cell fraction than rats fed NIH, whereas alpha-cell fraction and beta-cell size were not affected by diet or rat type. Apoptotic bodies of beta-cells were rare and unaffected by diet. The number of PCNA(+)beta-cells was not affected by diet. CK20 expression was localized in the ductular system and at the periphery of islets in rats aged 7 and 45 days. There were more CK20(+)islets in BBdp rats fed NIH than in those fed HC but the CK20 area fraction was unaffected by diet. Bcl-2 expression was scattered among ducts and central acinar cells. The number of extra-islet insulin(+)and glucagon(+)clusters (

Topics: Animals; Body Weight; Caseins; Cell Division; Diabetes Mellitus, Experimental; Homeodomain Proteins; Intermediate Filament Proteins; Islets of Langerhans; Keratin-20; Keratins; Rats; Rats, Inbred BB; Stem Cells; Trans-Activators

The dithiocarbamates are known to cause dermatitis, conjunctivitis, rhinitis, pharyngitis and bronchitis in humans. The experimental group received Propineb (obtained from Bayer) concentrations of 400 ppm in distilled water five days a week (treatment time three weeks) administered orally by gasric pit. Acute oral LD50 for male rats has been found to be 8,500 mg/kg (Worthing, 1983). The control group (n = 10) received only distilled water. At ultrasonographical examination, there were no resorbed fetuses or stillborns during or after propineb administration. It can be clearly seen that the body weights of the experimental group of litters are lower than those of the control group (p < 0.001). However, the mean length of the experimental litters was identical to the control group of litters (p > 0.05). Under microscopical examination, increased keratinization and hyperplasia were observed in the epidermal cells.

Topics: Animals; Animals, Newborn; Biopsy; Body Weight; Epidermis; Female; Fungicides, Industrial; Hyperplasia; Keratins; Male; Maternal-Fetal Exchange; Pregnancy; Rats; Rats, Wistar; Skin; Teratogens; Ultrasonography, Prenatal; Zineb

Keratinocytes are potentially appealing vehicles for the delivery of secreted gene products because they can be transferred to human skin by the relatively simple procedure of grafting. Adult human keratinocytes can be efficiently propagated in culture with sufficient proliferative capacity to produce enough epidermis to cover the body surface of an average adult. However, the feasibility of delivering secreted proteins through skin grafting rests upon (i) the strength of the promoter in keratinocytes and (ii) the efficiency of protein transport through the basement membrane of the stratified epithelium and into the bloodstream. In this paper, we use transgenic technology to demonstrate that the activity of the human keratin 14 promoter remains high in adult skin and that keratinocyte-derived human growth hormone (hGH) can be produced, secreted, and transported to the bloodstream of mice with efficiency that is sufficient to exceed by an order of magnitude the circulating hGH concentration in growing children. Transgenic skin grafts from these adults continue to produce and secrete hGH stably, at approximately 1/10 physiological levels in the bloodstream of nontransgenic recipient mice. These studies underscore the utility of the keratin 14 promoter for expressing foreign transgenes in keratinocytes and demonstrate that keratinocytes can be used as effective vehicles for transporting factors to the bloodstream and for eliciting metabolic changes. These findings have important implications for considering the keratinocyte as a possible vehicle for gene therapy.

Topics: Adult; Animals; Body Weight; Evaluation Studies as Topic; Gene Expression; Genetic Therapy; Human Growth Hormone; Humans; In Situ Hybridization; Keratinocytes; Keratins; Mice; Mice, Transgenic; Organ Size; Promoter Regions, Genetic; Protein Processing, Post-Translational; Radioimmunoassay; RNA, Messenger; Skin; Skin Transplantation; Tissue Distribution

Previous studies have used a rate model for examination of the histopathology of oral candidiasis or mucosal coverage with dental prostheses. These studies have been complicated by the presence of accumulated debris between mucosa and prostheses.. The present study was undertaken to develop further the Wistar rat as a suitable animal model on which to study the effects of dental prostheses on oral mucosa.. The effects of three dietary regimes, used for 7 and 14 days, upon debris accumulation under denture-like appliances and measurable epithelial parameters were analysed by computerised planimetry.. Individual variation in animal weights during the study was noted, with some appliance-wearing animals exhibiting a weight gain while others lost weight. A powdered diet used in a paste form gave the least accumulation of debris under appliances and the least differences between appliance wearers and controls.. The use of the Wistar rat model utilising the past diet described is indicated for future investigation of the effect of prostheses on oral mucosa.

Topics: Acrylic Resins; Analysis of Variance; Animal Feed; Animals; Basement Membrane; Body Weight; Denture, Complete, Upper; Disease Models, Animal; Epithelium; Equipment Contamination; Image Processing, Computer-Assisted; Keratins; Male; Mouth Mucosa; Palate; Rats; Rats, Wistar; Reproducibility of Results; Statistics, Nonparametric; Stomatitis, Denture; Surface Properties

To clarify the regeneration process of pancreatic beta-cells, we established a new mouse model of diabetes induced by selective perfusion of alloxan after clamping the superior mesenteric artery. In this model, diabetes could be induced by the destruction of beta-cells in alloxan-perfused segments, while beta-cells in nonperfused segments were spared. Intraperitoneal glucose tolerance tests showed glucose intolerance, which gradually ameliorated and was completely normalized in 1 year with a concomitant increase of insulin content in the pancreas. Histological examination showed neo-islet formation in the alloxan-perfused segment and the proliferation of spared beta-cells in the nonperfused segment. In the alloxan-perfused segment, despite a marked reduction of islets in size and number at an early stage, both the number of islets, including islet-like cell clusters (ICCs), and the relative islet area significantly increased at a later stage. Increased single beta-cells and ICCs were located in close contact with duct cell lining, suggesting that they differentiated from duct cells and that such extra-islet precursor cells may be important for beta-cell regeneration in beta-cell-depleted segment. In addition to beta-cells, some nonhormone cells in ICCs were positive for nuclear insulin promoter factor 1, which indicated that most, if not all, nonhormone cells positive for this factor were beta-cell precursors. In the nonperfused segment, the islet area increased significantly, and the highest 5-bromo-2-deoxyuridine-labeling index in beta-cells was observed at day 5, while the number of islets did not increase significantly. This indicated that the regeneration of islet endocrine cells occurs mostly through the proliferation of preexisting intra-islet beta-cells in the nonperfused segment. In conclusion, the regeneration process of beta-cells varied by circumstance. Our mouse model is useful for studying the mechanism of regeneration, since differentiation and proliferation could be analyzed separately in one pancreas.

Topics: Alloxan; Animals; Blood Glucose; Body Weight; Cell Division; Diabetes Mellitus, Experimental; Disease Models, Animal; Glucagon; Glucose Tolerance Test; Homeodomain Proteins; Immunohistochemistry; Insulin; Islets of Langerhans; Keratins; Male; Mice; Mice, Inbred ICR; Pancreatic Polypeptide; Perfusion; Regeneration; Somatostatin; Time Factors; Trans-Activators

The classical mouse fancy Agouti gene is responsible for the wild-type coat color where hairs are banded black and yellow. The Agouti gene encodes a 131-amino-acid secreted protein product that regulates phaeomelanin synthesis by melanocytes in mice. Mice with a dominant mutation at this locus, Ay, develop a yellow coat color, obesity, and diabetes, as the result of a deletion that results in ectopic overexpression of the Agouti gene mRNA in all tissues examined. Obesity and diabetes in Ay mutant mice could be caused by circulation of the protein, or localized action in specific tissues as a paracrine factor acting in cell-cell communication. To test these two possibilities, the Agouti cDNA was overexpressed in the skin of transgenic mice using either the Tyrosinase-Related Protein-1 or the keratin-14 (K14) promoter, the latter with and without an intron. The K14 promoter directed high constitutive levels of expression of Agouti mRNA in the skin, and several lines of transgenic mice exhibited coat colors resembling dominant Agouti allele phenotypes. Two highly expressing K14-Agouti transgenic lines, with light-yellow pelage, were analyzed for obesity and hyperglycemia. The transgenic mice were not significantly different from the controls (P > 0.05), indicating that the Agouti product does not act as an endocrine factor. RNase protection assays revealed a correlation between the levels of dorsal and ventral skin expression with pigmentation/phaeomelanin phenotypes. Co-injection experiments with the Agouti transgenes and other transgenes demonstrated co-integration of the two constructs at the same chromosomal site in approximately 95% of F1 progeny, allowing transgene inheritance to be visibly detected.

Topics: Agouti Signaling Protein; Animals; Base Sequence; Blood Glucose; Body Weight; Gene Expression; Gene Transfer Techniques; Genes, Dominant; Genetic Markers; Growth Substances; Hair Color; Intercellular Signaling Peptides and Proteins; Keratins; Membrane Glycoproteins; Mice; Mice, Transgenic; Molecular Sequence Data; Mosaicism; Mutagenesis; Oxidoreductases; Phenotype; Promoter Regions, Genetic; Protein Biosynthesis; Proteins; Recombinant Fusion Proteins; Skin Physiological Phenomena; Tissue Distribution

To study the involvement of cyclin D1 in epithelial growth and differentiation and its putative role as an oncogene in skin, transgenic mice were developed carrying the human cyclin D1 gene driven by a bovine keratin 5 promoter. As expected, all squamous epithelia including skin, oral mucosa, trachea, vaginal epithelium, and the epithelial compartment of the thymus expressed aberrant levels of cyclin D1. The rate of epidermal proliferation increased dramatically in transgenic mice, which also showed basal cell hyperplasia. However, epidermal differentiation was unaffected, as shown by normal growth arrest of newborn primary keratinocytes in response to high extracellular calcium. Moreover, an unexpected phenotype was observed in the thymus. Transgenic mice developed a severe thymic hyperplasia that caused premature death due to cardio-respiratory failure within 4 months of age. By 14 weeks, the thymi of transgenic mice increased in weight up to 40-fold, representing 10% of total body weight. The hyperplastic thymi had normal histology revealing a well-differentiated cortex and medulla, which supported an apparently normal T-cell developmental program based on the distribution of thymocyte subsets. These results suggest that proliferation and differentiation of epithelial cells are under independent genetic controls in these organs and that cyclin D1 can modulate epithelial proliferation without altering the initiation of differentiation programs. No spontaneous development of epithelial tumors or thymic lymphomas was perceived in transgenic mice during their first 8 months of life, although they continue under observation. This model provides in vivo evidence of the action of cyclin D1 as a pure mediator of proliferation in epithelial cells.

Topics: Aging; Animals; Base Sequence; Body Weight; Cattle; Cell Division; Crosses, Genetic; Cyclin D1; Cyclins; DNA Primers; Epidermis; Epithelium; Female; Humans; Hyperplasia; Immunohistochemistry; Keratins; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Inbred Strains; Mice, Transgenic; Molecular Sequence Data; Oncogene Proteins; Organ Size; Polymerase Chain Reaction; Promoter Regions, Genetic; Restriction Mapping; T-Lymphocyte Subsets; T-Lymphocytes; Thymus Gland; Vagina

Epidemiological studies have implied that Chinese salted fish is a human nasopharyngeal carcinogen. In the present study, 162 Sprague-Dawley rats were randomly assigned to one of four experimental groups. Rats in groups 1 (n = 41) and 3 (n = 40) were exposed to salted fish from birth through the breast feeding period by giving the maternal rats a diet containing 10% and 5% salted fish, respectively, later feeding the rats with pellets containing 10% and 5% of salted fish respectively. In group 2, the rats (n = 41) were given pellets containing 10% of salted fish from 6 weeks of age. Rats in group 4 (n = 40), serving as controls, were only given ordinary pellets. Three rats had nasopharyngeal tumours, 2 from group 1 had a poorly differentiated carcinoma and a squamous cell carcinoma. One rat from group 2 had a squamous cell carcinoma. Four rats had nasal tumours, one fibrosarcoma and one adenocarcinoma were found in rats from group 1. One rhabdomyosarcoma was found in group 2, and one soft tissue sarcoma was found in a rat in group 3. No nasal or nasopharyngeal tumours appeared in the control group. The difference in the occurrence of malignant nasal and nasopharyngeal tumours among the four experimental groups was statistically significant (one tailed p for trend = 0.041). The frequency of tumours appearing in other organs such as the breast, kidney, lung, liver and brain was not significantly different between the salted fish treated groups and the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adenocarcinoma; Animals; Animals, Newborn; Body Weight; Carcinoma; Carcinoma, Squamous Cell; Desmin; Diet; Female; Fibrosarcoma; Fishes; Food Preservation; Keratins; Male; Nasopharyngeal Neoplasms; Nose Neoplasms; Pregnancy; Rats; Rats, Sprague-Dawley; Rhabdomyosarcoma; Sarcoma, Experimental; Survival Rate; Vimentin

Miltefosine (hexadecylphosphocholine, HPC, CAS 58066-85-6) was investigated in transplanted primary methylnitrosourea-induced PYH mammary carcinoma of F344 rats. The therapy was performed in the 5th and 10th passage. At first HPC (113 mg/kg body weight) significantly reduced the median tumor volume, but a loss of activity was observed in the 10th passage. To explain the loss of sensitivity and to obtain information on the mechanism of action histology, cytoskeleton and hormone receptor content were investigated. The most important change was observed in the histopathology of the tumor. The initial tubular papillary adenocarcinoma was transformed into a malignant adenoacanthoma with epithelial structure. Vimentin as an endothelial marker of the cytoskeleton was equally expressed in all passages. Cytokeratin was weakly expressed in the earlier passages and intensively present in the late passages. The histopathological change from tubular adenocarcinoma to malignant adenoacanthoma might be caused by an overgrowth of the primary epithelial tumor cells or by a real transformation in the morphological characteristics of the tumor, which may occur during repeated transplantation.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Biomarkers, Tumor; Body Weight; Female; Keratins; Mammary Neoplasms, Experimental; Neoplasm Transplantation; Phosphorylcholine; Rats; Rats, Inbred F344; Vimentin

Effects of cyproterone acetate, a synthetic steroidal compound, on the reproductive organs of female rats have been investigated. This agent caused reduction of ovarian weights indicative of suppression of pituitary gonadotrophins. Oestrogenic nature of cyproterone acetate was investigated in intact and ovariectomized rats taking uterine weight and vaginal keratinization as an index of oestrogenicity. Cyproterone acetate in ovariectomized animals induced vaginal keratinization and increased the uterine weights. These effects were parallel to the effect of oestradiol dipropionate in ovariectomized animals, thus indicating oestrogenic activity of cyproterone acetate. We may conclude that the above compound caused antifertility effects due to its oestrogenic nature at the dose level of 2 mg/alternate day in rats when the compound was administered subcutaneously.

Topics: Animals; Atrophy; Body Weight; Castration; Cyproterone; Estradiol; Female; Fertility; Genitalia, Female; Hyperplasia; Hypertrophy; Keratins; Organ Size; Ovary; Rats; Reproduction; Uterus; Vagina

Biological properties of axerophthene, the hydrocarbon analog of retinol, have been studied both in vitro and in vivo. In tracheal organ culture axerophthene reversed keratinization caused by deficiency of retinoid in the culture medium; its potency was of the same order of magnitude as that of retinyl acetate. Axerophthene supported growth in hamsters fed vitamin A-deficient diets although less effectively than did retinyl acetate. Axerophthene was considerably less toxic than was retinyl acetate when administered repeatedly in high doses to rats. Administration of an equivalent p.o. dose of axerophthene caused much less deposition of retinyl palmitate in the liver than did the same dose of retinyl acetate, while a greater level of total retinoid was found in the mammary gland after administration of axerophthene.

Topics: Animals; Body Weight; Diterpenes; Female; Keratins; Liver; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Organ Culture Techniques; Rats; Retinyl Esters; Trachea; Vitamin A; Vitamin A Deficiency

Ducks maintained from hatching on zinc-deficient diets were retarded in growth and had severe lesions of the pedal epidermis, epithelia of the base of the tongue, oral surface of the larynx and nasal sinuses. Similar but milder changes affected the roof of the mouth, the crop and the oesophagus of a few cases. There was derangement of the architecture of the rete mucosum with loss of distinction between the cells of the stratum basale and stratum spinosum. Enlargement of the nuclei and nucleoli of these cells, widening of the intercellular space and dyskeratosis and degeneration, particularly of the prickle cells, were seen. Although epithelial atrophy occurred in early examples of the condition, acanthosis, hyperkeratosis and heterophil infiltration of the epithelial layers were characteristic of most cases. Erosion of the epithelium with the formation of purulent crusts ocntaining secondary bacterial foci was present and in these cases inflammatory phenomena occurred in the dermis. A small proportion of the nuclei of the pancreatic exocrine cells were enlarged and irregular in shape.

Topics: Animals; Body Weight; Ducks; Epithelium; Keratins; Larynx; Paranasal Sinuses; Poultry Diseases; Skin; Tongue; Zinc

Topics: Animals; Body Weight; Cilia; Epithelial Cells; Keratins; Methods; Mice; Microscopy, Electron; Microscopy, Electron, Scanning; Nasal Mucosa; Nasal Septum; Olfactory Mucosa; Organ Size; Species Specificity

Topics: Animal Nutritional Physiological Phenomena; Animals; Body Weight; Bone and Bones; Carbon Dioxide; Carbon Isotopes; Collagen; Cystine; Diet; Digestive System; Elements; Feces; Glycine; Hair; Keratins; Kidney; Liver; Male; Minerals; Muscle Proteins; Nutrition Disorders; Pancreas; Proline; Protein Biosynthesis; Rats; Respiration; Skin; Sulfur Isotopes; Testis; Zinc

Taste preferences were studied in two groups of rats depleted of vitamin A by dietary restriction. One group received sufficient vitamin A acid supplement to maintain normal growth. The other group was repleted with vitamin A alcohol after the classical deficiency symptoms had appeared; this group gradually lost normal preferences for NaCl and aversion to quinine solutions during depletion. Vitamin A alcohol repletion tended to restore taste preferences to normal. In contrast, the group receiving vitamin A acid showed normal taste preferences throughout the depletion period. When the vitamin A acid supplement was removed taste preferences became abnormal and returned to normal when vitamin A acid was restored. Peripheral gustatory neural activity of depleted rats without any form of vitamin A was less than normal both at rest and when the tongue was stimulated with NaCl solutions. Histological examination showed keratin infiltrating the pores of the taste buds. Accessory glandular tissues were atrophied and debris filled the trenches of the papillae. It is concluded that vitamin A acid can provide the vitamin A required for normal taste, as contrasted with its inability to maintain visual function. It is suggested that the effect of vitamin A is exerted at the receptor level, as a result of its role in the biosynthesis of mucopolysaccharides, which have been recently identified in the pore area of taste buds, as well as being present in the various secretions of the oral cavity.

Topics: Acetates; Animal Nutritional Physiological Phenomena; Animals; Body Weight; Chorda Tympani Nerve; Electrophysiology; Glycosaminoglycans; Keratins; Quinine; Rats; Sodium Chloride; Sucrose; Sweetening Agents; Synaptic Transmission; Taste; Taste Buds; Tongue; Vitamin A; Vitamin A Deficiency

Topics: Alkanes; Body Weight; Guinea Pigs; Hydrocarbons; Hyperplasia; Keratins; Keratosis; Keratosis, Actinic; Metabolism; Pharmacology; Research; Skin; Toxicology; Water

Topics: Animals; Body Weight; Keratins; Wool