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Biomedical subjects

M O Benoit

Publications and source records attributed to M O Benoit.

12 recordsLinked to original sources

[Hemodialysis and ferritinemia].

Iron-deficiency is a common phenomenon in chronic renal diseases and haemodialysis patients, a treatment with iron or transfusions is always provided in an early preventive way; yet, an overload may appear. Serum ferritin, in spite of analytic variability, remains at the present time a good witness to appreciate patients' iron stores. Authors report the results obtained with four commercial reagents in healthy population and in haemodialysed children or adults. The comparison of results for this parameter shows that haemodialysed sera, with or without treatment, have the same behaviour with reagents as those of healthy subjects.

Adult

Monitoring of heart allograft rejection by simultaneous measurement of serum beta 2-microglobulin and urinary neopterin.

In patients with heart transplant, the combined determination of serum beta 2-microglobulin and urinary neopterin, as rejection marker, prevented the interference by renal function and cyclosporin therapy. Unfortunately, the simultaneous measurement of these two parameters cannot distinguish between a rejection episode and the early stage of viral infection.

Biopterins

[Normal serum concentration of retinol transport protein (RBP) measured by an immunonephelometric method].

The authors give serum retinol binding protein (RBP) normal values, established by immunonephelometry, for two healthy populations in their hospital laboratory. The mean values for men's and women's group are significantly different. They note for women's group with estroprogestative drugs a higher mean value. Relations between retinol and RBP metabolism are known. RBP values give a good estimation of retinal reserves in patients.

Adult

[Diagnosis of AL amyloidosis in the absence of detectable serum or urinary monoclonal component].

A case of massive amyloidosis without detectable monoclonal Ig component either in serum or in urines on classical electrophoresis and without obvious plasma cell proliferation is reported. Immunohistochemical study of renal and bone marrow biopsies showed that amyloid deposits were specifically stained with the anti-lambda antiserum and that 92% of the plasma cells were also lambda positive. Immunofixation following electrophoretic analysis of serum and urinary proteins exhibited a monoclonal lambda light chain at an advanced stage of the disease. Simple but not routinely used techniques are therefore of great interest to characterize apparently idiopathic amyloidosis which could have therapeutic implications.

Aged

[A manual method for the direct determination of serum iron using a new chromogen: chromazurol B].

The authors describe a manual method for the direct assay of iron in human serum using the ammonium salt of Chromazurol B. This new chromogen reacts with ferric or ferrous ions and cetyltrimethylammonium bromide giving a purple ternary complex. Reliability and practicability of the method are studied. The results correlate very well either with those of the SFBC's method or with a direct ferrozine-guanidine kit. The reagents are very cheap, the method is quickly performed; no significant interference could be observed in case of high concentrations of added bilirubin, copper or hemoglobin.

Benzoates

[Magnesium deficiencies in cardiovascular diseases].

Plasma (pl), red blood cell (ery) and urinary magnesium (Mg) concentrations were measured by spectrophotometry in over 300 patients at the Cardiology Department of Broussais Hospital. Other biological parameters, including pl and ery potassium, calcium and phosphate concentrations were measured simultaneously. In a control group (54 subjects) the mean pl Mg was 0,851 mmol/l in men and 0,819 mmol/l in women; mean ery Mg was 2,12 mmol/l and 2,09 mmol/l respectively. Magnesium depletion was observed in several pathological cardiovascular conditions: -- mitral valve prolapse: the Mg levels were significantly lower in women (19 cases) (pl Mg 0,740 mmol/l; ery Mg 1,83 mmol/l: p less than 0,001); the deficit was less pronounced in men: pl Mg 0,829 mmol/l, p less than 0,01, and ery Mg 2,01 mmol/l (NS); -- recurrent junctional tachycardia (21 cases): the Mg levels were significantly lower than normal: pl Mg = 0,796 mmol/l in men and 0,763 mmol/l in women; ery Mg = 1,93 and 1,88 mmol/l, respectively; -- coronary insufficiency (86 cases): pl Mg = 0,821 mmol/l in men and 0,768 mmol/l in women (p less than 0,001). In a subgroup with coronary spasm (22 cases), the mean ery Mg was decreased (2,01 mmol/l, p less than 0,05); -- unstable or labile hypertension (24 cases): the decrease was significant, especially in women (pl Mg = 0,796 mmol/l, ery Mg = 1,88 mmol/l). These magnesium deficits were sometimes associated with a low pl Ca, and often associated with a low ery K although pl K was usually raised. In some privileged cases of cardiac arrhythmia and coronary spasm, intravenous Mg repletion was beneficial but did not affect plasma concentrations. The role of magnesium depletion in cardiovascular disease remains obscure and requires further study.

Adolescent

[Serum isoamylases determination. Analytical and critical study of a new method using an inhibitor protein].

A new method for the serum isoamylase assay is studied. Its principle is the use of an inhibitor protein from wheat, mainly active on the salivary type isoamylases. Amylase remaining in the presence of the inhibitor (R) and total amylase (T) are measured and the R/T ratios calculated. The kinetic of the inhibition is studied with various samples of pancreatic juice and saliva, of which the isoenzymatic pattern has been evidenced by electrofocusing. The results show that 80% of the salivary type isoamylases (S) and 20% of those from pancreatic type (P) are inhibited in the operational conditions described. The inhibition is stopped, but not modified, by addition of amylase activity substrate. The analytic study of the kit showed convenient results. The chemical inhibition methodology is compared with a modified Davies' electrophoretic technic on cellulose acetate membrane. The results are shown on a diagram: R/T ratio on the ordinate and total amylasemia on the abscissa. In the middle of the diagram appears an area which corresponds to normal values obtained with 69 healthy subjects from 20 to 30 years old.

Glycoside Hydrolases

[A study of the specificity of amylases. Measurement of pancreatic isoamylases (author's transl)].

Serum lipase, pancreatic isoamylases and serum inhibitory activity on proteases were measured in 29 patients, 17 of whom had pancreatic disorders. The new test used to measure pancreatic isoamylases is rapid and useful, as it is relatively specific of pancreatic lesions. In acute abdominal syndromes, it undoubtedly enhances the value of biochemical investigations by confirming or excluding pancreatic lesions or involvement.

Amylases