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Biomedical subjects

R Cahen

Publications and source records attributed to R Cahen.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Volumetric analysis of urinary erythrocytes in the etiological diagnosis of hematuria].

Intravenous pyelography and cystography may fail to localize the origin of haematuria. Microhaematuria is known to be present in 2 to 10 percent of the general population, usually without pathological consequences. Study of red cell morphology by phase contrast microscopy is effective in distinguishing between "glomerular" (from renal tissue) and "non-glomerular" (from urinary tract) erythrocytes, but this technique is not currently available in all laboratories. Urinary blood cell volume analysis has been presented as a simple and automatic alternative method. We compared these two techniques in 100 cases of haematuria of various origins. The cut-off point between glomerular and non-glomerular erythrocytes was set at 71 fl. Phase contrast microscopy always confirmed the clinical and/or histological diagnosis, but volume analysis did not: mean erythrocyte volume of glomerular origin was 66.6 +/- 10.4 fl, while non-glomerular volume was 94.5 +/- 17 fl (P < 0.001); cell volume analysis was confirmative in only 72 percent of all diagnoses (65 percent of microhaematurias, 83 percent of macrohaematurias); sensitivity was 65 percent and specificity 85 percent for glomerular erythrocytes. Due to poor performance, urinary red volume analysis is not an acceptable alternative method to phase contrast microscopy when searching for the site of bleeding.

Adolescent↗
PubMed1989

Aetiology of membranous glomerulonephritis: a prospective study of 82 adult patients.

Eighty-two consecutive Caucasian adults (52 males, 30 females, aged 17-86 years) with membranous glomerulonephritis were prospectively evaluated for possible aetiological factors 1-4 weeks after renal biopsy. Presumed causes were identified in 17 patients (21%) as follows: drugs in five (D-penicillamine 3, captopril 1, fenoprofen 1); malignancy in four; chronic thyroiditis in three; systemic lupus erythematosus (SLE) in two; secondary syphilis in one; hepatitis B virus (HBV) infection in one and non-insulin-dependent diabetes mellitus in one patient. Except for age (patients with secondary membranous glomerulonephritis were older), clinical presentation and histological stage distribution did not differ between the secondary and the primary groups. Ten out of the 17 patients with secondary membranous glomerulonephritis (59%) achieved complete clinical remission within 12 months. The incidence of associated conditions in adults with membranous glomerulonephritis in this study corresponds with that reported in the few previous series. Although membranous glomerulonephritis is deemed to be idiopathic in most cases, it seems warranted to search for medication, malignancy, SLE, HBV infection, syphilis and thyroiditis as possible aetiological factors. Further evaluation should be orientated by the clinical context. An improved outcome of membranous glomerulonephritis may be expected insofar as the underlying condition is controlled.

Adolescent↗
PubMed1987

[Glomerular nephropathy in the Bardet-Biedl syndrome].

A case of Bardet-Biedl syndrome (BBS) with kidney involvement and renal failure is reported. Light microscopy demonstrates fibrosis of 40% of glomeruli, altered tubules and interstitial fibrosis; no cystic formation is present and immunofluorescence studies are negative. In electron microscopy, the glomerular basement membrane (GBM) looks twisted and uniformly thickened with segmental effacement of the trilaminar architecture; fibrillary material is accumulated close to the inner layer of the GBM. Intermittent peritoneal dialysis is initiated 2 years later; death occurs, after one year of dialysis, due to a bleeding duodenal ulcer. Chronic renal failure seems to be the most frequent cause of death in BBS and several mechanisms are involved. Tubulo-interstitial lesions and renal cysts have been well documented. Glomerular damage with early ultrastructural changes of the GBM may be implicated in the occurrence of renal failure. Further studies are needed to define the incidence and the specificity of the GBM abnormalities in BBS.

Adult↗
PubMed1986

Inhibitors of urinary stone formation in 40 recurrent stone formers.

The excretion of four inhibitors of urinary stone formation (zinc, magnesium, citrates and glycosaminoglycans (GAG) was studied in 20 normal controls and 40 recurrent calcium stone formers who were placed on a fixed diet restricted in calcium, oxalates and purines. We were unable to show any abnormality in the excretion of Zn, Mg or GAG. In 11 patients, a low level of urinary citrate was a significant feature that was associated in most cases with a urinary pH value above 6. Citrate concentration (per litre) and output (per 24 h) were found to be lower than in the controls in 19 and 33% respectively of the determinations. The overall ratio of average urinary citrate concentration in patients and controls was 0.56, a figure in agreement with previous data.

Adult↗
PubMed1986

[Preventive medical treatment of recurrent urinary calcium calculi].

In 59 out of 80 patients with recurrent renal calcium stones studied between 1977 and 1982 and followed up for 4,5 to 7 years, an index has been used to determine the activity of the disease, before and after treatment with diet, high water intake, thiazide and/or allopurinol. As estimated by variations of the "activity index", the treatment was effective in all groups studied: patients with idiopathic hypercalciuria were prescribed a low purine and oxalate diet and a large water intake associated or not with thiazide; hyperuricosuric patients were treated by the same diet and allopurinol; patients with no metabolic abnormality were submitted to diet and/or thiazide and/or allopurinol. The association of thiazide and allopurinol seems to be a more effective therapy in recurrent stone formers with primary hyperoxaluria than high diuresis and succinimide.

Adult↗
PubMed1985

[Comparative study of urine immunoelectrophoresis and 4 indexes of glomerular selectivity in chronic glomerulopathies].

Glomerular selectivity has been evaluated in a group of 89 patients, using renal clearances of orosomucoid (Cl O), transferrin (cl T) and immunoglobulin G (Cl IgG). In all cases, protein excretion was found above 0,30 g/24 h and urinary immunoelectrophoresis (IEP) showed a glomerular pattern. Clearance ratios Cl IgG/Cl T and Cl T/Cl O as well as Joachim's and Sabot's indexes were correlated to IEP patterns, protein daily excretion, creatinin clearance and pathological findings. The ratio Cl T/Cl O and Joachim's and Sabot's indexes correlated significantly with IEP patterns while Cameron's ratio (Cl IgG/Cl T) did not. Criteria other than Cameron and Joachim's indexes were found to be related to protein excretion; all indexes, Cameron's excluded, were influenced by renal functional status. Progress may be expected from the simultaneous serum and urine determinations of 5 proteins in the range 40 000-1 000 000 molecular weight with more accurate techniques such as laser nephelometry.

Adolescent↗
PubMed1984

Do beta blockers prevent pressor responses to mental stress and physical exercise?

Do beta blockers prevent the elevation of blood pressure induced by physical exercise and mental stress? The variations of blood pressure and pulse rate observed with dynamic effort and during tests of mental calculation, colour stress, and grip strength were measured in 15 hypertensive patients, before and after treatment with atenolol (100 mg day-1) and in a series of 16 normotensive control subjects. With treatment, the systolic and diastolic blood pressures and the pulse rate were significantly lowered in the hypertensive patients at rest. The tests of mental stress and static physical effort caused a rise in blood pressure, significantly greater in the untreated patients than in the control subjects. Atenolol diminished the rise in systolic blood pressure and pulse rate secondary to a dynamic effort, but did not significantly alter the blood pressure variations induced by static physical effort and mental stress. These findings are in agreement with previous results obtained with other beta blockers.

Adrenergic beta-Antagonists↗
PubMed1983

[Localized pulmonary pseudo-tumoral form of Wegener's disease and fulminating evolution. Apropos of a case].

A case of Wegener's granulomatosis starting as a localized pseudo-tumoral lung lesion and following a fulminating course is reported. The histological diagnosis required thoracotomy. New pulmonary lesions developed post-operatively, together with severe renal failure which was responsible for the patient's death 5 weeks after the thoracotomy. The authors describe the lesions characteristic of the disease and their pathogenesis and discuss the relationship between Wegener's syndrome and other granulomatous angiitis.

Adult↗
PubMed1982

[Is the serum level of beta 2 microglobulin a better marker of glomerular filtration than blood creatinine?].

beta 2-microglobulin (b2M) serum level assessed by radioimmunoassay), creatinine serum level and Glomerular Filtration Rate (GFR, as measured by 125I iothalamate clearance) have been simultaneously determined in 53 controls and 123 patients with chronic renal disease (100 with chronic renal failure, GFR = 80-18 ml/min). In all groups studied, correlations between beta 2M and GFR showed no improvement over creatinine and GFR. The beta 2M serum level does not appear to be a more sensitive or reliable marker of GFR than is creatinine.

Adult↗
PubMed1982

[The kidney in systemic scleroderma. A report of 38 consecutive cases ].

The renal status of 38 patients with progressive systemic sclerosis (scleroderma) has been investigated by the usual clinical tests, urine electrophoresis, glomerular filtration rate (GFR) and renal plasma flow (RPF) determinations and in 4 cases by renal biopsy. Fourteen patients presented with proteinuria and/or a high serum creatinine and/or hypertension with low clearance values in all cases. In 14 other patients, an abnormality was apparent from clearance results (12 cases), renal biopsy (1), urine electrophoresis (1). The earliest sign of renal involvement that could be demonstrated was a reduced RPF and an elevated filtration fraction. Subsequently, a glomerular proteinuria with a electrophoretic pattern was observed as either the only sign (9 cases) or in association with abnormal clearance values (8 cases). The incidence of clinical renal involvement (proteinuria, renal failure, hypertension) ranged from 16 to 60%; 2/3 of patients who presented with proteinuria and hypertension died within 3 years. A mucoid thickening of intima and a fibrosis of adventitia in the proximal part of interlobar and arciform arteries, a fibrinoid necrosis in the distal part of lobular and preglomerular arteries are distinctive although inconstant features. The vascular lesions (seen in 70% of cases) and superimposed but reversible vasoconstriction, account for the decreased RPF. An effective control of blood pressure is mandatory; the therapeutic value of angiotensin converting enzyme inhibition remains to be corroborated.

Adult↗