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Biomedical subjects

N Schor

Publications and source records attributed to N Schor.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Effects of cyclooxygenase inhibitors on plasma and urinary kallikrein.

In vitro studies were performed to investigate the direct effects of the cyclooxygenase inhibitors (COI), meclofenamate, imidazol, acetylsalicylic acid (ASA), indomethacin, and acetaminophen on the plasma kallikrein system and on urinary kallikrein excretion. Biological (guinea pig ileum) and colorimetric (synthetic substrate) methods were used. Results showed that all COIs except ASA affected both the activation of pre-kallikrein in plasma and the direct activity of plasma kallikrein, but none of the COIs tested was able to alter the urinary kallikrein excretion. Additionally, in Wistar rats we studied the effects of chronic administration of ASA, meclofenamate, and indomethacin on the plasma kallikrein system and urinary kallikrein excretion. In contrast to the in vitro studies, administration of these COIs reduced the amount of total 24-hour urinary kallikrein excretion. Moreover, the pre-plasma kallikrein and total plasma kallikrein levels were diminished in all experimental groups. However, only ASA and meclofenamate increased the free-plasma kallikrein levels despite the fact the three COIs used reduced the high molecular weight kininogen. Thus, in vitro data suggest an important and direct effect of meclofenamate, imidazol, indomethacin, and acetaminophen on the plasma kallikrein system, without any effect on urinary secretion. ASA was the only COI that showed no direct effect in these experiments. Chronic COI administration in Wistar rats suggests that ASA, meclofenamate, and indomethacin affect both the plasma kallikrein-kinin system and kallikrein excretion. When these drugs are used to evaluate the interactions between prostaglandins and the kallikrein-kinin system, their possible effects through both mechanisms, directly or via prostaglandin inhibition, should be considered.

Animals↗
PubMedDate not supplied

[Kidney glomerular hemodynamics in the rodent Calomys callosus].

Renal function was characterized in Calomys callosus, a rodent which can participate in the transmission of several human diseases. The results showed that the pressures levels, hematocrit and plasmatic proteins were similar to rats submitted to the same experimental maneuvers. The corporal and renal weights, whole and single nephron glomerular filtration rates were similar to the mouse. This rodent presented a significant number of superficial glomeruli, allowing to evaluate glomerular hemodynamics and renal microcirculation parameters. Despite mean arterial pressure similar to the Munich-Wistar (MW) rats, mean glomerular capillary hydraulic pressure was lower in Calomys callosus, due to a lower post glomerular resistance in this rodent when compared to MW rats. The mean glomerular plasma flow rate was relatively elevated when compared with single nephron glomerular filtration rate, which in turn blunted the lower intraglomerular hydraulic pressure, and thus increased the single nephron glomerular filtration rate per g/kidney. The present work suggests that despite of the technical difficulties imposed by the reduced size of the Calomys callosus, the study of the renal function and glomerular hemodynamics is possible, establishing therefore, a model for the study such renal function.

Animals↗
PubMedDate not supplied

[Women and contraception: knowledge and use of contraceptive methods].

This article analyzes knowledge and use of contraceptive methods in women ages 10 to 49 years residing in the southern region of the city of São Paulo in 1992. A total of 1,157 childbearing-age women were studied, focusing on variables that might define them as to: knowledge in the use of contraceptive methods and reasons for choosing a given method. We observed that 86% of the women referred knowledge of some contraceptive method, while the most common was the pill (95.3%), followed by condoms (92.6%). Meanwhile, 14% of the interviewees denied knowledge of any contraceptive method. Of the sexually active women (66.4%), 34.9% reported never having used contraceptive methods. Of those who had, 35.3% used the pill, while 42.9% had resorted to sterilization. Only 5.2% used condoms. Despite the high level of knowledge concerning contraceptive methods, especially oral contraceptives and condoms, we observed limited use of same as compared to the high sterilization rate around the age of 27, thus leaving contraception limited to the pill and female sterilization.

Adolescent↗
PubMedDate not supplied

[The physician-scientist: from academy to partnership].

OBJECTIVES: To illustrate the changes in academy and in industry that are reshaping the profile of the physician-scientist. METHODS AND RESULTS: Data were extracted from the literature and from primary sources as well as from the authors' own experiences. CONCLUSIONS: Within an academy-industry relationship, the market demands a physician-scientist best suited to orient research activities towards patient-oriented and disease-oriented goals.

Academies and Institutes↗
PubMedDate not supplied

Ligation of the left renal vein in epm1-Wistar rats: functional and morphologic alterations in the kidneys, testes and suprarenal glands.

OBJECTIVE: The ligation of the left renal vein (LLVR) in man is a controversial procedure in view of the risks of lesion to the renal parenchyma. With the objective of studying the morphologic and functional alterations caused by these lesions, we conducted experimental research with rats. MATERIAL AND METHODS: 64 male adult EPM1-WISTAR rats were used, divided into 8 groups-4 for LLRV and four for control. Each LLRV group and corresponding control group were sacrificed progressively on the 7th, 15th, 30th and 60th day after the initial surgery. RESULTS: We found morphofunctional alterations only in animals that underwent LLRV in the four periods of sacrifice. The proteinuria creatinine in serum, testosterone in serum and serum corticosterone in serum showed practically no alteration in relation to the normal values for rats. Statistically significant severe histological lesions were found in the kidneys and testes of the LLRV groups. Lesions in the suprarenal glands were also present in these groups, but no sufficient to demonstrate statistical significance. CONCLUSION: Based on these results we can conclude that the ligation of the left renal vein is a procedure of high risk in these animals.

Adrenal Glands↗
PubMedDate not supplied

[Evaluation of three plants with potential diuretic effect].

To evaluate three natural products with potential diuretic effect, Elephantopus scaber, Alpina speciosa and Tradescantia diuretica it was performed a trial of acute administration in 10 healthy volunteers, with interval of 7 days for each dose, except Tradescantia diuretica which was administered with 60 days of interval. All groups were compared with placebo group. The three products were given doses 5 times higher than the usually preconized by the popular use, i.e., 7.5 g/100mL, 0.8g/100mL and 25g/100mL of water, respectively. Besides physical examination, plasmatic and urinary parameters of sodium, potassium, uric, acid, calcium, phosphate, urea, creatinine and total urinary volume were evaluated. The only significant data were a light increase in diuresis (p < 0.05) with Alpinia speciosa, which also lowered the mean diastolic (p < 0.05) and systolic (p < 0.01) blood pressure. We did not found any effect in electrolytes excluding therefore, a tubular effect of these teas in modifying Na, K, Ca, P and uric acid excretions, as well as any detectable glomerular action since no changes were observed in renal function parameters.

Adult↗
PubMedDate not supplied

[Renal artery aneurysm].

Patients with haematuria should be submitted to deep investigative protocol, for a more accurate diagnosis. Thus, we report a case of macroscopic haematuria and the set of complementary examinations that led to the diagnosis of this rare pathological entity. The classification (etiological or morphological), diagnosis, surgical intervention indications and therefore the treatment (embolization or surgical) were pointed out. Accurate diagnosis is obtained through Renal Digitalis Arteriography after the morphological assessment of the normal urinary tract (UGE and renal US) and the evidence of unilateral bleeding (cystoscopy).

Adult↗
PubMedDate not supplied

[Recurrent hematuria in children: study of 250 cases].

In order to analyse the etiology of recurrent hematuria in childhood, we studied 250 children, referred to our Service (age: 6 mo-17 ys; 102 female and 148 male). They were submitted to the following protocol: urine analyses, uroculture, serum total and fraction complement, electrophoresis of hemoglobin, serum creatinine, BUN, 24h urinary calcium, uric acid and protein, oral calcium load test in children with hypercalciuria (UCa greater than 4mg/kg/day). Radiological evaluation and renal percutaneous biopsy was performed when necessary. The following diagnostic distribution was obtained: Alport syndrome, 19; Berger disease, 15; other glomerulopathies, 45; hypercalciuria, 67; uric acid hyperexcretion, 10; nephrolithiasis, 27; urinary tract infection, 14; renal malformation, 8; no diagnosis, 43. Based in these results, we conclude that appropriate investigation on recurrent hematuria, leads to determination of etiology in over 80% of cases.

Adolescent↗
PubMedDate not supplied

[Primary hyperparathyroidism: clinical and laboratory spectrum].

The authors analyze clinical and laboratorial features of 13 patients with surgically confirmed primary hyperparathyroidism (HPT). Among them, 8 presented renal lithiasis, 7 had bone disease, and 2 had both. All patients were hypercalcemic and had elevated serum carboxyterminal levels of PTH. The aminoterminal portion of the PTH was above the normal range in 9 patients and inappropriately high for the level of serum calcium in other two. The c'AMP was elevated in 7/8 patients. Hypophosphatemia was detected in 8/11 patients. Among the lithiasic patients, hypercalciuria was found in only 3. Five patients were submitted to an oral calcium load test which detected no intestinal hyperabsorption of calcium (IH) secondary to HPT in any of them. The rate of elimination of stones/patient/year was 1.7 before the establishment of HPT diagnosis. Despite the presence of renal lithiasis, hypercalciuria and IH were not common findings in HPT patients. Serum calcium and urinary c'AMP were the best screening tests for the diagnosis of HPT in this series. The diagnosis should be further confirmed determining the PTH.

Adult↗
PubMedDate not supplied

[Quantitative analysis of blood loss in liposuction].

This study was performed in 15 female patients submitted to suction lipectomy as an isolated procedure, to establish blood loss in the procedure. A wide variation of blood-to-fat ratios was observed (17 to 59%) with a mean blood loss in lipoaspirates of 34 +/- 3%. Internal blood losses occurring in the first 72 post-operative hours were as important as or more important than external losses, and responsible for a mean 7% fall in the level of hemoglobin. Internal blood losses occurred between 72 hours and the 7th to the 10th post-operative days and were responsible for a mean 3% fall in the level of hemoglobin. Blood losses occurring in this study were demonstrated to be greater than usually assumed. Some prophylactic measures are recommended to provide for a safer treatment of these patients: an iron supplementation during the pre-operative period; careful clinical and laboratorial screening for bleeding disorders and for the intake of drugs that can interfere with coagulation; use of smaller-diameter cannulas for aspiration, auto-transfusion when aspirating in excess of 1,000 ml, and limiting the aspiration to 1,500 ml.

Adult↗