muramidase and Virus-Diseases

The airway provides numerous defense mechanisms to prevent microbial colonization by the large numbers of bacteria and viruses present in ambient air. An important component of this defense is the antimicrobial peptides and proteins present in the airway surface fluid (ASF), the mucin-rich fluid covering the respiratory epithelium. These include larger proteins such as lysozyme and lactoferrin, as well as the cationic defensin and cathelicidin peptides. While some of these peptides, such as human beta-defensin (hBD)-1, are present constitutively, others, including hBD2 and -3 are inducible in response to bacterial recognition by Toll-like receptor-mediated pathways. These peptides can act as microbicides in the ASF, but also exhibit other activities, including potent chemotactic activity for cells of the innate and adaptive immune systems, suggesting they play a complex role in the host defense of the airway. Inhibition of antimicrobial peptide activity or gene expression can result in increased susceptibility to infections. This has been observed with cystic fibrosis (CF), where the CF phenotype leads to reduced antimicrobial capacity of peptides in the airway. Pathogenic virulence factors can inhibit defensin gene expression, as can environmental factors such as air pollution. Such an interference can result in infections by airway-specific pathogens including Bordetella bronchiseptica, Mycobacterium tuberculosis, and influenza virus. Research into the modulation of peptide gene expression in animal models, as well as the optimization of peptide-based therapeutics shows promise for the treatment and prevention of airway infectious diseases.

Topics: Animals; Antimicrobial Cationic Peptides; Cathelicidins; Cystic Fibrosis; Defensins; Disease Models, Animal; Humans; Lactoferrin; Muramidase; Proteinase Inhibitory Proteins, Secretory; Proteins; Respiratory System; Toll-Like Receptors; Tuberculosis, Pulmonary; Virus Diseases

Topics: Animals; Animals, Newborn; Bacterial Infections; Blood Bactericidal Activity; Body Temperature; Chick Embryo; Chickens; Egg Proteins; Egg Shell; Female; Infections; Intestines; Muramidase; Mycoses; Ovalbumin; Phagocytosis; Skin; Transferrin; Virus Diseases; Vitelline Membrane

Topics: Animals; Bacteria; Bacterial Infections; Central Nervous System Diseases; Circadian Rhythm; Diagnosis, Differential; Hepatitis A; Leukemia; Lysosomes; Muramidase; Periodicity; Rabbits; Rats; Virus Diseases

Topics: Herpes Simplex; Herpes Zoster; Humans; Lichen Planus; Muramidase; Stomatitis, Aphthous; Virus Diseases

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents; Anti-Inflammatory Agents; Bacteria; Drug Synergism; Female; Fever; Genital Diseases, Female; Guinea Pigs; Haplorhini; Humans; Infections; Inflammation; Mice; Muramidase; Penicillins; Peritoneal Diseases; Phagocytosis; Pneumococcal Infections; Rabbits; Rats; Staphylococcal Infections; Urologic Diseases; Virus Diseases; Viruses

Topics: Animals; Antigens; Bacteria; Cell Wall; Guinea Pigs; Humans; Mice; Muramidase; Phagocytosis; Rabbits; Rats; Virus Diseases

Human viruses possess very complex supramolecular structures. Both icosahedral and enveloped viruses typically display an array of viral-encoded protein antigens at varied spatial densities on the viral particle surface. The viral nucleic acid genome, on the other hand, is encapsulated inside the viral particle. Although both the surface antigen and the interior nucleic acids could independently produce immunological responses, how B cells integrate these two types of signals and respond to a typical virus particle to initiate activation is not well understood at a molecular level. The study of these fundamental biological processes would benefit from the development of viral structural mimics that are well constructed to incorporate both quantitative and qualitative viral features for presentation to B cells. These novel tools would enable researchers to systematically dissect the underlying processes. Here we report the development of such particulate antigens based on liposomes engineered to display a model protein antigen, hen egg lysozyme (HEL). We developed methods to overexpress and purify various affinity mutants of HEL from

Topics: Animals; Antigens, Viral; B-Lymphocytes; Biomimetic Materials; Liposomes; Models, Molecular; Muramidase; Protein Conformation; Vaccination; Virus Diseases

The aim of this study was to evaluate the diagnostic capacity of a number of blood components such as soluble adhesion molecules, interleukin-6 (IL-6), myeloperoxidase (MPO) and lysozyme in the distinction of acute bacterial and viral infections. Blood was taken from 115 acutely infected patients at admission before any treatment and in some cases on several consecutive days. 35 of the patients had a definite viral cause for their infection and 66 a bacterial cause. All variables were raised in patients with acute bacterial infections. Soluble vascular cell adhesion molecule-1 (sVCAM-1), sE-selectin, lysozyme and MPO were also raised in acute viral infections, but for sE-selectin and MPO less so than in bacterial infections. Evaluation of the diagnostic power showed that for MPO and IL-6 at cut-offs of 1300 microg/l and 100 ng/l, respectively, the positive predictive value was 97% and 100% and the negative predictive value 78% and 76%, respectively, in the classification of acute bacterial infections. In the distinction between viral or bacterial causes of acute infections in otherwise healthy subjects serum measurements of MPO and IL-6 are valuable tools and should be considered as diagnostic aids in the routine setting. The soluble adhesion molecules did not offer any further information in this respect.

Topics: Acute Disease; Adolescent; Adult; Aged; Aged, 80 and over; Bacterial Infections; Biomarkers; Cell Adhesion Molecules; Child; Cytokines; Diagnosis, Differential; E-Selectin; Female; Humans; Intercellular Adhesion Molecule-1; Interleukin-6; Male; Middle Aged; Muramidase; Peroxidase; Predictive Value of Tests; Vascular Cell Adhesion Molecule-1; Virus Diseases

The presentation of infection in immunocompromised patients can be subtle. Patients often undergo extensive testing and empiric treatment for rejection and infection while awaiting the results of the biopsy and culture results. Delay in diagnosis of either entity can result in a worse clinical outcome. Lysozyme activity has been found to be both a sensitive and a specific marker for infection in laboratory animals and trauma patients. Our goal was to determine whether lysozyme activity could serve as a reliable marker for infection in immunocompromised organ transplant recipients.. Transplant recipients from three clinical categories were enrolled in this study. Group 1 (n = 16) were patients hospitalized for sepsis (culture-positive), and Group 2 (n = 13) for biopsy-proven rejection. Group 3 (n = 51) were recipients who had routine blood sampling in the clinic. In Groups 1 and 2, blood was collected within 24 h of hospital admission and centrifuged, and serum samples were stored at 80 degrees C until processing. Lysozyme activity was assayed by turbidimetric measurement on a sample of a standard suspension (0.15 mg/ml) of Micrococcus lysodeikticus in buffer using a spectrophotometer to read the optical density at 450 nm. The lysozyme activity level was then determined by the measuring activity at 1 min subtracted from activity at 4 min. White blood cell count was determined by using a flow cytometer. Statistical comparisons between groups were made using paired Student's t test.. Serum lysozyme was found to be significantly elevated in Group 1; the mean level of activity was 60.1 +/- 13 (P < 0.05) compared to the level of activity in Group 2, mean 41.1 +/- 11, and Group 3, mean 40.8 +/- 13. A level of 45 units of activity/ml of serum or above indicated infection and not rejection in the patients admitted to the hospital.. These findings indicate that the lysozyme activity assay appears to be useful in differentiating infection from rejection in transplant recipients.

Topics: Adolescent; Adult; Aged; Bacterial Infections; Graft Rejection; Humans; Middle Aged; Muramidase; Organ Transplantation; Reference Values; Surgical Wound Infection; Virus Diseases

Cerebrospinal fluid lysozyme (CSF-LZM) concentrations were determined in 62 controls, 28 viral meningitis and 22 bacterial meningitis, as compared to CSF lactic acid routinely used. CSF-LZM measurement was performed by a rapid turbidimetric assay which required 50 microliters CSF only. The mean CSF-LZM concentration of the control group was 0.23 mg/l, the highest value being 0.65 mg/l. The mean LZM levels in viral meningitis were 1.10 mg/l, never exceeding 3 mg/l. The range of pretreatment LZM levels in bacterial meningitis was 7.2 to 65 mg/l and above 3 mg/l in all cases 48 h after treatment. On the 6th day after admission, 12 of 16 samples showed abnormal values. The CSF-LZM assay seems to be of more value than that of lactic acid. Thus, before treatment, LZM concentrations were 10 to 100 fold higher than that of the normal values, with persistent high levels on the 2nd and even on the 6th day of treatment (whereas lactic acid values were all normal on day 6).

Topics: Analysis of Variance; Bacterial Infections; Child; Child, Preschool; Humans; Infant; Lactates; Lactic Acid; Meningitis; Muramidase; Photometry; Protein C; Virus Diseases

The effects of season and variations in the prevalence of infectious disease on the concentrations and daily production of breast-milk immunoproteins were studied in 152 rural Gambian mothers and their children up to 26 months post-partum. IgA, IgG, IgM, C3, C4, lactoferrin, lysozyme and secretory component concentrations and breast-milk volumes were measured longitudinally over a six month period which encompassed dry and rainy seasons. No increase in the production of any immunoprotein was observed at the time of maximum prevalence of serious infectious diseases, especially diarrhoea, in the children. Enhanced secretion of certain immunoproteins was noted in mothers of children aged 9-18 months at the beginning of the rainy season. There was some evidence that this may have been associated with skin sepsis, particularly impetigo, in the children. The production of most immunoproteins fell during the rainy season. This was not the result of declining maternal food intakes as similar decreases were seen for women receiving a dietary supplement.

Topics: Bacterial Infections; Complement C3; Complement C4; Developing Countries; Female; Gambia; Humans; Immunoglobulins; Infant; Infant Nutritional Physiological Phenomena; Infant, Newborn; Lactation; Lactoferrin; Milk, Human; Muramidase; Mycoses; Pregnancy; Rural Population; Seasons; Secretory Component; Virus Diseases

Topics: Acute Disease; Adolescent; Child; Humans; Mucus; Muramidase; Nasal Mucosa; Respiratory Tract Infections; Saliva; Virus Diseases

The CSF levels of lactoferrin, lysozyme, and beta 2-microglobulin (beta 2 mu) were measured in patients with evident, probable, or possible inflammatory CNS reactions and compared to those found in neurologically apparently healthy patients. Patients with viral CNS infections had significantly raised beta 2 mu and lysozyme levels but normal lactoferrin levels, indicating a local activation of lymphocytes and monocytes but not of granulocytes. Patients with bacterial CNS infections had significantly raised levels of all three cell markers, but the increase of lysozyme and lactoferrin was relatively more pronounced than that of beta 2 mu, indicating that the inflammatory response to bacterial agents is dominated by monocytes and granulocytes. Patients with primary or secondary malignant brain tumors were characterized by a moderate increase of beta 2 mu and a considerable increase in both lysozyme and lactoferrin, i.e., the same protein pattern as observed in bacterial CNS infection. The lysozyme levels were moderately increased in half the patients with benign cerebral tumors while the levels of beta 2 mu and lactoferrin were normal, indicating that benign and malignant brain tumors induce different local inflammatory CNS reactions. Half the patients with pituitary gland adenoma had elevated beta 2 mu and lysozyme levels but normal lactoferrin levels, suggesting that immunological mechanisms are associated with the adenoma development. Patients with MS had moderately but significantly raised CSF levels of beta 2 mu and lysozyme and a third of them also had raised levels of lactoferrin, a protein pattern suggesting a low-active inflammatory process in CNS involving mononuclears and granulocytes. A similar protein pattern was found in Guillain-Barré syndrome. In cerebrosarcoidosis we noted considerably increased lysozyme and beta 2 mu but normal lactoferrin levels, consistent with the idea that the sarcoid granuloma mass is dominated by monocytic inflammatory cells. The data obtained indicate a clinical value of lactoferrin, lysozyme, and beta 2 mu as differential indices of inflammatory cell reactions taking place in various CNS processes.

Topics: Adult; Albumins; Bacterial Infections; beta 2-Microglobulin; Beta-Globulins; Central Nervous System Diseases; Cerebrospinal Fluid Proteins; Female; Humans; Inflammation; Lactoferrin; Lactoglobulins; Male; Muramidase; Virus Diseases

Topics: Bacterial Infections; Child; Colitis, Ulcerative; Crohn Disease; Diagnosis, Differential; Feces; Hepatitis A; Humans; Meningitis; Meningitis, Aseptic; Muramidase; Urinary Tract Infections; Virus Diseases

Topics: Adult; Aged; Amino Acids; Betamethasone; Deglutition Disorders; Galantamine; Glossopharyngeal Nerve; Humans; Male; Muramidase; Pharyngeal Diseases; Pyrrolidines; Syndrome; Thiamine; Virus Diseases; Vitamin B 12

Topics: Adolescent; Bacterial Infections; Child; Child, Preschool; Female; Humans; Immunosuppressive Agents; Infant; Male; Muramidase; Virus Diseases

A new methodological approach to the study of the organism resistance to infection with the use of experimental animals with controlled microflora (germfree and other categories of gnotobiotic animals) is considered. Characteristics of the state of natural resistance of germfree animals, revealing considerable defects of cellular and humoral protection mechanisms, are given. Findings of experimental studies into inflammation, phagocytosis and other reactions of nonspecific resistance in gnotobiotic animals, disclosing complex mechanisms of formation of these reactions under the influence of microflora, are presented. The etiological and pathogenetic role of the microbial factor in the development of infectious diseases and in the formation of mechanisms of protective reactions at various levels of integration of the organism are discussed. Conclusions concerning prospects of the gnotobiological approach in investigating the role of the microbic factor in pathology are set forth.

Topics: Animals; Antibody Formation; Bacterial Infections; Burns; Cell Movement; Complement System Proteins; Germ-Free Life; Growth; Guinea Pigs; Immunity, Cellular; Infections; Inflammation; Intestines; Leukocytes; Mice; Muramidase; Phagocytosis; Properdin; Rats; Virus Diseases

Topics: Agammaglobulinemia; Age Factors; Bacterial Infections; Bronchitis; Child, Preschool; Chronic Disease; Complement System Proteins; Humans; Immunoglobulin A; Immunoglobulin G; Infant; Muramidase; Virus Diseases

Topics: Animals; Chromatography; Chromatography, Gel; Culture Media; Haplorhini; Humans; Interferons; Muramidase; Ribosomes; RNA, Viral; Virus Cultivation; Virus Diseases

Topics: Child; Complement System Proteins; Enterovirus Infections; Humans; Muramidase; Respiratory Tract Infections; Virus Diseases

Topics: Dermatologic Agents; Muramidase; Neoplasms; Pain; Virus Diseases

Topics: Antiviral Agents; Dermatologic Agents; Humans; Mumps; Muramidase; Parotitis; Stomatitis; Virus Diseases

Topics: Anti-Infective Agents, Local; Antiviral Agents; Dermatologic Agents; Dermatology; Muramidase; Virus Diseases

Topics: Antiviral Agents; Dermatologic Agents; Humans; Muramidase; Skin Diseases; Virus Diseases

Topics: Anti-Bacterial Agents; Antibiotics, Antitubercular; Child; Dermatologic Agents; Humans; Infant; Infections; Muramidase; Sepsis; Virus Diseases