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Biomedical subjects

R D Lindeman

Publications and source records attributed to R D Lindeman.

98 records · Page 6Linked to original sources

Serum concentrations and urinary excretions of zinc in cirrhosis, nephrotic syndrome and renal insufficiency.

Serum zinc conentrations are decreased in patients with a variety of clinical disorders including cirrhosis, nephrotic syndrome and renal insufficiency. Urinary zinc excretions are increased in the first two disease states. Symptoms of acute zinc deficiency (anorexia, dysfunction of smell and taste and mental and cerebellar disturbances) and chronic zinc deficiency (growth retardation, anemia, testicular atrophy and impaired wound healing) are common in these patients. It remains unresolved whether these low serum zinc concentrations in these disease states are indicative of true symptomatic or asymptomatic zinc deficiency, or merely reflect a decrease in available zinc-binding proteins, as well over 90% of serum zinc is bound to protein in normal subjects. The correlation between serum zinc and albumin concentrations, reportedly the major zinc-binding protein, is unimpressive. Studies of serum and urine binding of added radiozinc65 using Sephadex G-200 gel column chromatography and polyacrylamide gel electrophoresis suggest most of the radiozinc is bound to a protein with a molecular weight near albumin (68,000). Polyacrylamide gel electrophoresis suggests this might be a prealbumin. The low serum zinc concentration in the patient with nephrotic syndrome does not appear to be due to loss of zinc bound to urinary protein.

Adult↗

Case report: acute pancreatitis following corticosteroid and azathioprine therapy.

Several drugs have been implicated as causes of acute pancreatitis. This report presents four patients, three with lupus nephritis and one with membranous glomerulopathy, who developed acute pancreatitis while being treated with corticosteroids alone or in combination with azathioprine. Two of the reported patients died with a hemorrhagic pancreatitis and one of the patients developed a pancreatic pseudocyst. The pathogenesis of corticosteroid and/or azathioprine-induced pancreatitis is discussed.

Acute Disease↗

Influence of synthetic corticosteroids on plasma zinc and copper levels in humans.

The effects of varying doses of a short-acting (methylprednisolone) and a long-acting (dexamethasone) synthetic glucocorticoid on extent and duration of alterations in plasma zinc and copper concentrations in normal humans are documented. Early after intravenous administration of either steroid, increases in plasma zinc and copper levels were observed. By 12 hours, plasma zinc concentrations had decreased below control levels and the extent and duration of the depression depended on the dosage of the steroid administered. No significant decrease was noted beyond 48 hours. The plasma copper levels did not decrease until after zinc levels began returning toward normal, reaching a peak depression at 48 hours and, at high doses of steroids, persisting until completion of the study at 96 hours. This difference in the time sequence suggests that different mechanism control plasma concentrations of the two metals. The serum zinc levels may depend on ACTH-adrenal interactions, while the slower response of the serum copper levels may depend on changes in the rate of synthesis of the serum copper-binding protein, ceruloplasmin.

Adult↗

Changes in renal function with aging. Implications for treatment.

The most important clinical renal function to monitor with aging is the glomerular filtration rate (creatinine clearance). Most decisions on drug dosage can be based on this information alone as other (tubular) functions of the kidney decrease at rates paralleling the decrease in glomerular filtration rate. As individuals age, mean creatinine clearances fall at a rate approximating 1% per year and there is an increasing variance in creatinine clearances making it increasingly important to adjust drug dosages for changes in renal function. Since muscle mass and urinary creatinine excretions decrease at nearly the same rate, mean serum creatinine concentrations stay nearly constant. One must be aware of this phenomenon when using serum creatinine concentrations alone to determine drug dosages and intervals.

Aging↗

Prevalence of self-reported illnesses in elderly Hispanic and non-Hispanic Whites in New Mexico.

OBJECTIVE: To report on the prevalences of self-reported illnesses from the New Mexico Elder Health Survey. DESIGN: Randomized community-based cross-sectional survey of elderly (> or = 65 years of age) Hispanics and non-Hispanic Whites. METHOD: Analysis of data from the 883 participants in the New Mexico Elder Health Survey. RESULTS: Complete data on 848 subjects were available for this analysis: Hispanic males, 212; Hispanic females, 189; non-Hispanic White males, 236; non-Hispanic White females, 211. The mean age was 74 years (age range 65-98). Hispanics had fewer years of school and lower income. Hispanics reported a significantly (P<.05) higher prevalence of type 2 diabetes; leg ulcers/pressure sores; and Parkinson's Disease. Non-Hispanic Whites reported a significantly (P<.05) higher prevalence of asthma; circulatory problems; stomach (not ulcers), intestinal or gallbladder disease; urinary tract disorders (other than kidney disease); and cancer. Prevalence odds ratios and confidence intervals were calculated. Hispanic males reported a higher prevalence of type 2 diabetes (OR 1.88, CI 1.10-3.26, P = .02), and lower prevalences of asthma (OR 0.43, CI 0.18-0.93, P = .04); urinary tract disorders, other than kidney disease (OR 0.59, CI 0.38-0.91, P = .01); and cancer (OR 0.31, CI 0.13-0.68, P = .005). Hispanic females reported a higher prevalence of diabetes (OR 3.01, CI 1.48-6.50, P = .003), and a lower prevalence of glaucoma (OR 0.48, CI 0.22-1.00, P = .05). These differences remained significant after adjustment for age, education, income, and language. CONCLUSION: There are significant differences in the prevalences of self-reported illnesses between Hispanic and non-Hispanic White elderly.

Aged↗

Rapid development of glomerular crescents in epinephrine-infused dogs.

A serendipitous finding in the kidneys examined by light, electron, and immunofluorescence microscopy (LM, EM, and IFM, respectively) in mongrel dogs infused intravenously with epinephrine (4 microgram per kg per min) alone or in combination with therapeutic agents over a six hour period was proliferating epithelial cells in Bowman's space and adhesion to the Bowman's membrane (crescent). This lesion was observed in 10 of 17 dogs. In five, over 50 percent of the glomeruli were involved. In seven additional dogs infused with epinephrine, renal biopsy studies (LM) at 0, 3 and 6 hr periods revealed crescents only in the six hr specimens. By EM, the crescents were composed of actively proliferating epithelial cells with many large mitochondria containing conspicuous intramitochondrial particles. Fibrin was found within glomerular and peritubular capillaries, within tubules but rarely in the crescent. IFM revealed granular deposits of IgG only in the glomerular basement membrane and mesangium. Other changes included necrosis of the tubules in all dogs receiving epinephrine alone and necrosis of arterioles in some of the dogs studied. Dogs receiving normal saline infusions (control) did not reveal any abnormalities in the kidney. This model should prove useful in determining the morphogenesis of crescent formation and in evaluating the effect of therapeutic agents in the prevention of this lesion.

Animals↗

An electron microscopic technique for the study of elastic tissue in small arteries and arterioles of the kidney.

Elastic tissue content and distribution were studied by electron microscopy of small arteries and arterioles of kidneys obtained from normotensive Wistar and spontaneously hypertensive rats, normal dogs and patients with hypertension and glomerular diseases. Specificity and sensitivity of silver tetraphenyl porphyrin sulfonate stain are discussed. This specific electron microscopy technique should prove useful in analysis of elastic tissue in pathologic states of other organs, especially where elastic tissue normally appears to be sparse or absent.

Animals↗