deamino-arginine-vasopressin and Atrophy

We analysed a large sample of children diagnosed with urinary tract malformations and/or infections and calculated diagnostic efficiency and quality indexes for five different functional markers, with the goal of testing which is the most sensitive for detecting a loss of renal parenchyma.. Ours was a cross-sectional retrospective study in which the clinical histories of 179 paediatric patients (91 male and 88 female) were evaluated. In 102 of these patients (57%), a scintigraphy revealed loss of parenchyma. The most commonly observed morphological type of damage was renal scarring. All patients had undergone at least one desmopressin urine concentration test. We also analysed albumin/creatinine and N-acetyl-glucosaminidase (NAG)/creatinine ratios, glomerular filtration rate (GFR), and urine volume.. By distributing patients according to normal/abnormal scintigraphy, we observed statistically significant differences between the two groups in maximum urine osmolality and GFR. Urine volume was elevated in 31.3% of cases (sensitivity: 37.9%; specificity: 81.8%) and 24% had a defect in renal concentrating ability (sensitivity: 30.4%; specificity: 84.8%). Urinary albumin excretion was high in 12.2% of patients, and 7.2% had a high NAG/creatinine ratio. GFR was low in only 5.7% of patients. These last two markers were the least sensitive but most specific for detecting a loss of renal parenchyma (100%).. In our study, the most sensitive functional tests for detecting the loss of renal parenchyma were the two that take into account the ability of the kidney to manage water, i.e. urine volume and maximum urine osmolality. These two tests had specificity >80%. However, the maximum specificity was obtained by the NAG/creatinine ratio and GFR, which were, conversely, the least sensitive tests. A normal GFR does not necessarily show normal renal function.

Topics: Acetylglucosaminidase; Adolescent; Albuminuria; Atrophy; Biomarkers; Child; Child, Preschool; Creatinine; Cross-Sectional Studies; Deamino Arginine Vasopressin; Female; Glomerular Filtration Rate; Humans; Infant; Kidney; Kidney Concentrating Ability; Male; Osmolar Concentration; Radionuclide Imaging; Retrospective Studies; Sensitivity and Specificity; Urinary Tract Infections; Urogenital Abnormalities; Vesico-Ureteral Reflux

In mammals, the hormonal regulation of water homeostasis is mediated by the aquaporin-2 water channel (Aqp2) of the collecting duct (CD). Vasopressin induces redistribution of Aqp2 from intracellular vesicles to the apical membrane of CD principal cells, accompanied by increased water permeability. Mutations of AQP2 gene in humans cause both recessive and dominant nephrogenic diabetes insipidus (NDI), a disease in which the kidney is unable to concentrate urine in response to vasopressin. In this study, we generated a line of mice with the distal COOH-terminal tail of the Aqp2 deleted (Aqp2(Delta230)), including the protein kinase A phosphorylation site (S256), but still retaining the putative apical localization signal (221-229) at the COOH-terminal. Mice heterozygous for the truncation appear normal. Homozygotes are viable to adulthood, with reduced urine concentrating capacity, increased urine output, decreased urine osmolality, and increased daily water consumption. Desmopressin increased urine osmolality in wild-type mice but had no effect on Aqp2(Delta230/Delta230) mice. Kidneys from affected mice showed CD and pelvis dilatation and papillary atrophy. By immunohistochemical and immunoblot analyses using antibody against the NH(2)-terminal region of the protein Aqp2(Delta230/Delta230) mice had a markedly reduced protein abundance. Expression of the truncated protein in MDCK cells was consistent with a small amount of functional expression but no stimulation. Thus we have generated a mouse model of NDI that may be useful in studying the physiology and potential therapy of this disease.

Topics: Animals; Aquaporin 2; Atrophy; Cell Line; Deamino Arginine Vasopressin; Diabetes Insipidus, Nephrogenic; Disease Models, Animal; Diuresis; Dogs; Drinking; Gene Deletion; Heterozygote; Homozygote; Kidney Concentrating Ability; Kidney Medulla; Kidney Pelvis; Kidney Tubules, Collecting; Mice; Mutation; Osmolar Concentration; Protein Structure, Tertiary

Case report.. To present a case of central diabetes insipidus (CDI) that developed after a gunshot injury to the thorax and thoracic spinal cord and to discuss the disease process in light of the relevant literature.. Antidiuretic hormone (ADH) abnormalities may develop after spinal trauma and/or surgery. Although there are published reports of inappropriate ADH syndrome arising in this clinical picture, CDI is rare.. A 33-year-old woman with hemopneumothorax and a gunshot wound to her thoracic spine was treated with chest tube drainage. No surgery was performed for the spinal injury. The patient was paraplegic on admission and rapidly developed excessive urine output. Testing revealed that her serum ADH level was low, consistent with CDI. Desmopressin acetate nasal spray was the prescribed treatment.. The patient responded well to the desmopressin acetate spray.. CDI is a complicated hormonal disorder characterized by excessive urine output. It is typically linked to an abnormality in the hypothalamohypophyseal axis that markedly reduces ADH production. The most common inciting causes are craniocerebral trauma, brain tumor and/or surgery, and central nervous system infection. Although uncommon, CDI should be considered when a spinal trauma patient develops excessive urine output.

Topics: Administration, Intranasal; Adult; Atrophy; Deamino Arginine Vasopressin; Diabetes Insipidus, Neurogenic; Female; Hemostatics; Humans; Magnetic Resonance Imaging; Spinal Cord; Spinal Cord Injuries; Thoracic Injuries; Thoracic Vertebrae; Thorax; Treatment Outcome; Wounds, Gunshot