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Biomedical subjects

A Chagnac

Publications and source records attributed to A Chagnac.

71 records · Page 4Linked to original sources

Effect of long-term aluminum administration on the renal structure of the rat.

Kidneys of patients on hemodialysis therapy often undergo structural changes leading to acquired cystic disease. A wide variety of chemical compounds are known to induce experimental renal cystic disease. Since aluminum intoxication has been implicated in the development of encephalopathy, osteomalacia and anemia in uremic patients, this study was designed to investigate whether aluminum administration to normal rats could induce renal morphological changes. Male Wistar rats were divided into three groups; Animals of the Low-dose aluminum (LDA) group received 0.2 mg/day of aluminum, animals of the high-dose aluminum (HDA) group received 2 mg/day of aluminum; the third group consisted of controls (C). Aluminum was injected intraperitoneally as aluminum chloride (6 days a week). 13 weeks later, the kidneys were removed and examined by light and electron microscopy. The findings on eight-microscopic examination were normal in all groups. Electron-microscopic examination was unremarkable in the C and LDA group. In HDA rats, ultrasections of the cortex and outer medulla showed changes in the proximal tubules with increased size and number of lysosomes, osmiophilic granular material inside the lysosomes, vacuolisation of organelles and mitochondrial damage of varying degree. No cystic changes were found.

Aluminum↗

Effect of verapamil on plasma parathyroid hormone.

The effects of the Ca antagonist, verapamil, on the behaviour of parathyroid hormone was studied in normal and uraemic male Wistar rats. Parathyroidectomy was by cautery. Acute uraemia was induced by bilateral nephrectomy, and moderate uraemia by s.c. injection of gentamicin (200 mg/kg). Ethylendiamine tetracetic acid (50 mg/kg X d) was injected subcutaneously. Parathyroid hormone was determined by radioimmunoassay. The degree of uraemia was determined from plasma urea levels. Renal failure resulted in a significant increase in plasma parathyroid hormone (mean +/- SEM, ng/l) (84 +/- 6, n = 10, in the control; 277 +/- 39, n = 7, in the moderate uraemics and 667 +/- 128, n = 6, in the acute uraemics). Injection of verapamil significantly increased plasma levels of parathyroid hormone, ranging from 21% in the controls to 62% in the moderate uraemia group. In the acute uraemics, parathyroid hormone levels were very high and verapamil did not cause any further elevation of the hormone in the blood. Parathyroidectomy significantly lowered plasma parathyroid hormone, and verapamil resulted in a mean increase of 29%. EDTA caused an increase of 64%, compared with the control group.

Acute Kidney Injury↗

Acute renal failure in a solitary kidney due to bacterial pyelonephritis.

Deterioration of renal function after acute bacterial pyelonephritis is rare. We report on 2 patients with a solitary functioning kidney in whom acute renal failure developed in the setting of acute bacterial pyelonephritis. Following antimicrobial treatment kidney function returned to baseline values. This finding suggests that patients with a solitary functioning kidney are more prone to have renal dysfunction after acute bacterial pyelonephritis.

Acute Kidney Injury↗

Captopril as a replacement therapy in hypertension improving quality of life--a multicentre study.

A multicentre study was undertaken to determine whether side effects induced by hypotensive drugs could be reduced by replacement with low dose captopril. There were 100 patients on combinations of drugs, including diuretics, beta-blocking agents, methyldopa, clonidine and vasodilators. A questionnarie to obtain information on quality of life was completed by the patients. Each patient had major drugs, possibly responsible for side effects, withdrawn. Captopril was added at an initial dose of 12.5 up to 25 mg b.i.d. and titrated to a maximum of 50 mg t.i.d., until the blood pressure was equal to or lower than the level on entry into the study. Blood pressure was measured every two weeks and questionnaries were completed a number of times during the treatment period and scored at random, not in chronological order. A marked drop in blood pressure was obtained: mean systolic blood pressure went down from 173.4 +/- 2 to 154.5 +/- 2 mm Hg and diastolic blood pressure dropped from 104.5 +/- 11 to 9l.5 +/- 12 mm Hg. Neither tachycardia nor orthostasis was observed. Side effects, including inability to concentrate, nightmares, dizziness and sexual dysfunction, were reduced in 36% of the patients. Captopril itself produced no significant additional adverse reactions. It is concluded that captopril is a safe and effective drug, which can replace antihypertensive drugs that have deleterious side effects.

Adult↗

Combined tubular dysfunction in medullary cystic disease.

A patient with medullary cystic disease presented with a combined tubular dysfunction, including severe salt wasting, renal tubular acidosis types I and IV, and marked aldosterone resistance. High-dose mineralocorticoid treatment partially corrected the defect in potassium excretion and did not affect natriuresis. Plasma aldosterone level was more than 30 times the upper normal level and was decreased but not normalized by captopril administration and volume expansion. The severe hemodynamic and metabolic consequences of these defects were corrected by renal transplantation.

Acidosis, Renal Tubular↗

Effects of verapamil and bepridil on occlusion and reperfusion arrhythmias in the canine heart.

The effects of verapamil and bepridil on occlusion and reperfusion ventricular arrhythmias including ventricular fibrillation (VF) were studied in a canine model. The control group consisted of 27 dogs. 30 dogs received intravenous verapamil (0.2 mg/kg/3 min followed by a continuous infusion of 0.01 mg/kg/min for 15 min). 18 dogs received bepridil (0.5 mg/kg/min for 10 min). The left anterior descending coronary artery was occluded in one step 8 min after the commencement of verapamil administration and 5 min after the termination of bepridil infusion. The incidence of ventricular arrhythmias during the occlusion period was 14 (VF, 5/14), 13 (VF, 0/13) and 14 (VF, 9/14) in the control, verapamil and bepridil groups, respectively. The frequencies of reperfusion VF were 8/24 (33%), 4/30 (13.3%) and 0/13 (0%), respectively. It was concluded that (a) verapamil effectively prevents occlusion but not reperfusion VF and (b) bepridil has an arrhythmogenic effect in the ischemic canine heart but reduces the incidence of reperfusion VF.

Animals↗

Hypercalcemia associated with transitional cell carcinoma without bone metastases: description of two cases.

Two cases of hypercalcemia associated with transitional cell carcinoma and negative bone scan are described. In both cases hypercalcemia appeared while there was evidence of tumor spread. Although hypercalcemia was controlled, both patients died shortly thereafter. Hypercalcemia rarely occurs in transitional cell carcinoma and its appearance may suggest spreading of the tumor and poor prognosis.

Aged↗

Effects of dantrolene sodium on occlusion and reperfusion arrhythmias in the canine heart.

The effects of dantrolene sodium on occlusion and reperfusion ventricular arrhythmias (VA) were studied in a canine model. Transient ischemia was induced by a 10 min occlusion period of the left anterior descending coronary artery in 27 control dogs and 32 dogs pretreated with dantrolene sodium (2.5 mg/kg). In the control group, 14 (52%) dogs experienced VA during occlusion. Five of these had ventricular fibrillation, 3 of which were fatal. Eight of 24 control dogs which reached reperfusion experienced ventricular fibrillation during the first 30 sec of reperfusion. Dantrolene sodium did not lower the frequency of VA during occlusion 22/32 (69%). Moreover, the incidence of fatal ventricular fibrillation during occlusion was significantly (p less than 0.025) higher in the drug treated-group (12/32; 37.5%) than in the control group (3/27; 11%). Dantrolene sodium also significantly reduced the time that lasted from the commencement of occlusion to the appearance of ventricular fibrillation (240 +/- 1 sec versus 166 +/- 9 seconds, control and drug group, respectively p less than 0.05) without significantly altering either heart rate or blood pressure (169 +/- 4 b.p.m., and 170 +/- b.p.m.; 101 +/- 10 mmHg and 104 +/- 9 mmHg, before and after dantrolene sodium, respectively). These results indicate that dantrolene sodium might have an arrhythmogenic effect in the ischemic canine heart.

Animals↗

Liver granulomas: a possible paraneoplastic manifestation of hypernephroma.

A patient with hypernephroma presented with signs of liver dysfunction. Liver biopsy disclosed the presence of granulomas. Extensive search for a known cause of hepatic granulomas was negative. The presence of granulomas in lymph nodes draining the neoplasm, the improvement of liver dysfunction after nephrectomy, and its aggravation preceding overt metastatic manifestation support the existence of a cause and effect relationship between the renal cell carcinoma and the liver granulomatous disease.

Aged↗

Effect of verapamil on uremic myocardial disease in the rat.

It has been shown that calcium content of myocardium is increased in uremia and calcium overload has been implicated in the genesis of uremic myocardial disease. To determine whether verapamil (V) may prevent the development of myocardial lesions in uremic rats, the left ventricular myocardium has been examined with an electron microscope (EM) in 4 groups of Wistar male rats: 1) subtotally nephrectomized (SNX, n = 10); 2) SNX treated by V, 1.5 mg/kgx2/day (SNX-V, n = 8); 3) sham-operated (Sh, n = 5); 4) Sh treated by V (Sh-V, n = 5). EM examinations were performed after 13 weeks of uremia and V treatment. Serum urea and creatinine were similar in SNX and SNX-V rats and were higher in SNX and SNX-V than in Sh and Sh-V rats. The mitochondria of the myocardium in SNX rats showed damage of varying degree, starting from disrupted cristae to very dense mitochondrial structure with barely visible cristae. Myofibrils appeared disorganised with marked clear intermyofibrillar spaces. The myocardial ultrastructure of Sh, Sh-V and SNX-V rats was normal. It may be concluded that V seems to prevent the development of myocardial damage in the uremic rats.

Animals↗

Prevalence of Raynaud's phenomenon in patients with migraine.

We assessed the prevalence of Raynaud's phenomenon (RP) in 111 migrainous patients and 111 controls matched for age and sex. While 29 (26%) of the 111 migrainous patients suffered from RP, its prevalence among the controls was seven (6%) of 111. Raynaud's phenomenon was diagnosed among 13 (33%) of 39 patients with classic migraine and 16 (22%) of 72 patients with common migraine. Drug treatment did not account for the different prevalence in the two groups. We conclude that RP occurs more frequently in patients suffering from migraine than in the non-migrainous population.

Adolescent↗

The morphological changes in acute renal failure due to rhamdomyolysis following viral infection.

A case of myoglobinuric renal failure associated with viral rhabdomyolysis is described. Clinical signs of muscle involvement were lacking, but peculiar biochemical abnormalities suggested the diagnosis which was established by renal biopsy. The management required brief supportive hemodialysis, and the patient recovered. The diagnosis of myoglobinuria should be considered when acute renal failure develop subsequently to the onset of viral infection.

Acute Kidney Injury↗

Infectious endocarditis in idiopathic hypertrophic subaortic stenosis: report of three cases and review of the literature.

Three cases of infective endocarditis (IE) occurringg in patients with idiopathic hypertrophic subaortic stenosis (IHSS) are described. A review of the literature reveals the IE occurs in about 50 percent of the patients suffering from IHSS. It appears to complicate the natural history of the severe cases, at least as it appears from hemodynamic studies, being precipitated by the same factors and caused by the same infective organisms as in valvular heart disease. It has the same clinical picture and outcome, although the appearance of new murmurs was more common than in other types of heart disease complicated by IE, and indicated the same poor prognosis. The infection seems to involve both the aortic and the mitral valve, with equal frequency, and less commonly the ventricular outflow tract. The need for IE prophylaxis in cases of IHSS is stressed.

Adolescent↗

Effects of disopyramide on reperfusion arrhythmias in dogs.

We tested the effect of disopyramide on reperfusion arrhythmias in mongrel dogs. The control group consisted of 27 dogs. Twenty-nine dogs received two intravenous doses of disopyramide (total: 5.3 mg/kg) before and during the occlusion of the left anterior descending coronary artery. The blood levels of disopyramide averaged 3.95 +/- 0.95 micrograms/ml and 5.9 +/- 1.1 micrograms/ml, 2.5 and 9.5 min after the ligation. The incidence of reperfusion arrhythmias was significantly (p less than 0.05) lower in the treated group (7.5%) than in the control group (33.3%). Disopyramide also lowered the incidence of arrhythmias during the occlusion period (14% vs. 52%, p less than 0.01). Both groups showed a correlation between the incidence of arrhythmias during the occlusion period and on reperfusion.

Animals↗

Staphylococcal infections in PD: monitoring, screening and prevention.

Peritonitis and catheter infections remain a major complication of peritoneal dialysis, accounting for much of the morbidity associated with the technique. The most common source of infection is contamination with predominantly Gram positive skin flora, Staphylococcus (S) epidermidis and S. aureus. The aims of this study were, (a) to determine the incidence of S. aureus and S. epidermidis infections in the unit, (b) to examine whether treatment of S. aureus carriers may reduce the incidence of exit site infection and (c) to examine whether improving patient education may reduce S. epidermidis peritonitis rate.

Adult↗