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Biomedical subjects

A M Klein

Publications and source records attributed to A M Klein.

26 records · Page 2Linked to original sources
PubMed1985

Effect of aluminum on the renal handling of phosphate in the rat.

The effects of aluminum (Al) on the renal handling of phosphate (Pi) were studied by clearance techniques in the presence and absence of endogenous parathyroid hormone (PTH) and after Pi infusion. In all groups, a 1-h control period was followed by three 1-h experimental periods in which controls continued to receive saline and experimental animals received Al. Glomerular filtration rate, urine flow rate, and plasma sodium (Na) were not significantly changed between periods in any group. In the presence of endogenous PTH, the fractional excretion of phosphate (FEPi) increased significantly after 3 h of Al infusion (6.1 +/- 0.9 to 15.0 +/- 1.8%, P less than 0.05, n = 8), but not in controls (n = 7), while plasma calcium and Pi decreased, suggesting a PTH effect. However, in acutely thyroparathyroidectomized (TPTX) rats the FEPi also increased significantly after 3 h of Al infusion (4.3 +/- 3.0 to 10.6 +/- 4.2%, P less than 0.05, n = 7), but not in controls (n = 6). In TPTX rats infused with Pi where plasma Pi was increased to 10 mg/dl, FEPi increased significantly after 2 and 3 h of Al (7.0 +/- 1.4 to 15.5 +/- 2.1 to 16.9 +/- 2.2%, P less than 0.01, n = 15), but not in controls (n = 8). In this group, changes in FEPi were accompanied by a small but significant increase in FENa but not urinary cAMP. Blood pH was not significantly different between saline and Al-infused rats. These studies indicate that Al infusion inhibits renal Pi reabsorption by a mechanism independent of PTH, blood pH, or cAMP.

Aluminum↗
PubMed1985

[Comparative study of analgesia and plasma level following rectal, intramuscular and intravenous administration of ketamine].

Ketamine 25 mg/kg was administered to five foxhounds by the intravenous, intramuscular or rectal route. Plasma concentrations were measured by gas-chromatography and analgesia was tested by two techniques. Intravenous application gave reliable analgesia and well reproducible plasma levels in all subjects. Distribution and elimination half lives were found to be 6 min and 55 min, respectively. Intramuscular injection resulted in peak-plasma levels around the twentieth minute, elimination half life was fifty-two minutes, bioavailability 90%. Analgesia proved satisfactory in four out of the five subjects and lasted longer than after intravenous injection. The rectal route produced a wide range of peak-plasma levels, the average peak appearing after 40 min. We found an elimination halflife of 43 min and a bioavailability of 30%. Analgesia was poor in four out of the five subjects. The low plasma levels following rectal application are due to the poor bioavailability and this appears to be the reason for the unsatisfactory results with this route of administration. Bioavailability depends on the site of application (drainage mainly through the vena cava or portal vein) and the pH of the rectum.

Analgesics↗
PubMed1982

Antibody to hepatitis A and hemodialysis.

Antibody to hepatitis A virus (anti-HAV) was surveyed in 469 patients from 20 of 31 Michigan hemodialysis units, during spring 1978. The mean point prevalence of anti-HAV was 59.5% and within the 20 individual units ranged from zero to 100%. For the entire survey population, the point prevalence of anti-HAV was significantly greater with increasing age, among blacks, and in individuals with hypertension as their underlying renal disease. Anti-HAV was independent of sex, duration of dialysis, or the presence of either hepatitis B surface antigen or its associated antibody. Within individual units, anti-HAV prevalence was associated with a higher mean patient age but not with dialysis unit size, mean duration of dialysis therapy, race, or prevalence of hepatitis B markers among patients or staff. These data support reports that transmission of the hepatitis A virus is neither associated with hemodialysis therapy nor routinely spread by parenteral mechanisms as observed in hepatitis B virus transmission.

Adolescent↗
PubMed1980

Fluid administration and bronchopulmonary dysplasia. The lack of an association.

The fluid intake of 38 surviving infants with severe respiratory distress syndrome was evaluated. There were no substantial difference in fluid administration between those in whom bronchopulmonary dysplasia (BPD) developed and those in whom it did not. The factors that were associated with the development of BPD were the degree of prematurity, patent ductus arteriosus, pulmonary air leak, exposure to high concentrations of oxygen, and use of ventilation at faster rates.

Ductus Arteriosus, Patent↗
PubMed1980

Hyaline membrane disease. A controlled study of inspiratory to expiratory ratio in its management by ventilator.

Sixty-nine neonates with severe hyaline membrane disease (HMD) were mechanically ventilated using either a 1:2 or a 2:1 inspiratory to expiratory (I/E) ratio. Survivors in the 2:1 group required a lower fraction of oxygen in the inspired air (FiO2) and lower end-expiratory pressure to achieve satisfactory oxygenation. During the first week of life, time of exposure to FiO2 greater than 0.60 while being mechanically ventilated was 29.7 +/- 7.5 hours for the 1:2 group and 6.6 +/- 2,7 hours for the 2:1 group, while time of exposure to end-expiratory pressure greater than 3 cm H2O was 49.4 +/- 7.9 hours for the 1:2 group and 13.4 +/- 7.4 hours for the 2:1 group. Mortality and the incidence of air leak, patent ductus arteriosus, intraventricular hemorrhage, necrotizing enterocolitis, bronchopulmonary dysplasia, and pulmonary hemorrhage were not different for the two groups. Using an increased I/E ratio during the acute phase of HMD improved oxygenation but did not alter morbidity or mortality.

Carbon Dioxide↗
PubMed1975

Congenital hypothyroidism--signs and symptoms in the newborn period.

Infants with athyrotic hypothyroidism usually manifest signs and symptoms of hypothyroidism prior to or during the period in the newborn nursery. These features are variable and include: prolonged gestation with large size at birth, large posterior fontanel, respiratory distress, hypothermia, peripheral cyanosis, hypoactivity, poor feeding, lag in onset of stooling, abdominal distension with vomiting, protracted icterus, and/or edema. Retrospective assessment of newborn nursery records of three infants from the Collaborative Perinatal Project who were subsequently found to have congenital hypothyroidism disclosed that they had six, eight, and nine, respectively, of these features while in the newborn nursery. Evaluation of newborn records on 12 other infants, often less complete, who were later found to have congenital hypothyroidism disclosed that each infant had from one to seven of these signs and symptoms, with an average of 3.2 per infant. Thus the most important period for clinical consideration of athyrotic hypothyroidism is in the newborn nursery to initiate early thyroid replacement therapy in affected infants.

Birth Weight↗