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Biomedical subjects

M Vanhaeverbeek

Publications and source records attributed to M Vanhaeverbeek.

At least 19 recordsLinked to original sources

[Comparison of 2 techniques for measuring lymphocyte proliferation: tritiated methyl-thymidine incorporation and propidium iodide fluorometry].

In vitro lymphocyte mitogenic stimulation by phytohemagglutinin A was determined in 20 subjects, comparing tritiated thymidine incorporation and nuclear propidium iodide fluorescence. Unexpectedly, no correlation could be found between the two measures. The pitfalls of both methods are reviewed and discussed. The inability to validate one test by the other restricts the interpretation of the results obtained with one method and prevents their generalization. Without another gold-standard at the present time, specific and limited method-dependent norms should be defined.

Fluorometry

Thiobarbiturate and fructosamine assays: significance and interest of the borohydride blank.

The acute-phase reaction (APR) induces the production by the liver of short-lived glycoproteins. The carbohydrate moiety of these proteins is thought to interfere with the thiobarbiturate (TBA) and nitroblue tetrazolium colorimetric tests which are used for assaying non-enzymatic glycosylation (NEG) of serum proteins. The aim of the present study was to assess the effect of the APR on the specificity of the colorimetric tests in non-diabetic and diabetic subjects. A positive correlation was found between C-reactive protein (CRP), an APR glycoprotein, and non-specific TBA reactivity as determined after borohydride reduction (BH4-resistant TBA, BR-TBA), both in non-diabetics (r = 0.61; P < 0.01) and diabetics (r = 0.68; P < 0.01). The BH4-sensitive specific TBA (SP-TBA) was not influenced by glycoproteins, and its increase in diabetics was correlated with the nitroblue tetrazolium assay (r = 0.89; P < 0.01). An independent effect of diabetes and APR on non-specific TBA was also demonstrated, suggesting an effect of hyperglycaemia on both protein glycation and glycosylation. TBA with borohydride reduction is an attractive tool for the study of complex glycoproteins in diabetes.

Acute-Phase Reaction

Hormonal status and clinical relevance of hirsutism in elderly women.

Hirsutism is a common condition of elderly women, but its aethiopathogeny and its clinical implications remain unclear. We therefore studied circulating androgen concentrations in elderly women. In addition, this study aims to define a possible relationship between hirsutism and anthropometric determinations, bone mass and serum lipids. Androgen levels were determined at basal state, after adrenocorticotrophin (ACTH) stimulation and after dexamethasone administration in 10 hirsute elderly women and compared to 10 age-matched non-hirsute women. Anthropometric determinations included measurements of skinfold thickness and body mass index. Spinal bone mass density was assessed using dual photon absorptiometry. Hirsute women presented significantly higher levels of testosterone than controls (1.49 +/- 0.38 vs 0.59 +/- 0.05 nmol/l, mean +/- SEM; p < 0.05) and dihydrotestosterone (0.54 +/- 0.07 vs 0.32 +/- 0.03; p < 0.02). 17-hydroxyprogesterone levels after ACTH stimulation tended to be higher in hirsute women than in controls. No differences were observed between the two groups in serum oestrogen concentrations, plasma lipid pattern or bone mineral density. Hirsute women had a lower body mass index and lower calculated percentage body fat than the control group. We conclude that: (i) hirsutism of elderly women is associated with increased androgen levels, probably from adrenal origin; (ii) in some cases, enhanced response in 17-hydroxyprogesterone after ACTH stimulation suggests a partial adrenal 21-hydroxylase deficiency; (iii) hirsute women present anthropometric characteristics compatible with the known anabolic effect of androgens on fat-free mass.

Adrenocorticotropic Hormone

[Fulminant hepatic failure of neoplastic origin].

The case of a 59-year-old woman, hospitalised for a degradation of her health status which evolved within 10 days in fatal liver failure is reported. Although acute yellow atrophy was diagnosed, its origin remained elusive. Post-mortem examination of the liver disclosed massive hepatic infiltration by a breast adenocarcinoma. The causes of acute hepatic failure are reviewed and, particularly, the neoplastic ones.

Adenocarcinoma

Emission tomography for assessment of diffuse alcoholic liver disease.

A method of quantitative liver tomoscintigraphy (SPECT) was compared for accuracy with planar scintigraphy (PS) in a group of patients with diffuse alcoholic liver disease. SPECT sensitivity was also compared with that of transmission computed tomography (CT), US, aminopyrine breath test (ABT) and liver chemistries (LC). One hundred and fourteen alcoholic patients with proven liver disease and 17 patients free of liver disease were included. Seven quantitative scintigraphic features and a score, including all criteria were considered. With a specificity of 95%, the sensitivity was 79% in steatosis and 97% in cirrhosis. SPECT showed a better sensitivity than PS (SPECT 89%, PS 66%), especially in patients with steatosis. In the same subsets of patients, SPECT sensitivity also compared favorably with that of transmission CT (SPECT 92%, CT 65%), ultrasonography (SPECT 88%, US 53%) and ABT (SPECT 90%, ABT 63%).

Alanine Transaminase

[The concept of utility in decision strategies: application to diagnosis and treatment of renovascular hypertension].

To select a guideline in the management of diagnosis and treatment of renovascular hypertension, the clinician has to take into account many contradictory elements. He has to weight the invasive nature and the relative accuracy of the diagnostic tests, as well as the efficacy and drawbacks of medical and surgical treatments. The concept of utility in a decision making tree may lead to objective determination of best suited management for a given patient, according to the prior probability he had a renovascular hypertension.

Algorithms

Changing pattern of CD5+ CD20+ double positive lymphocytes with ageing and cytotoxic chemotherapy.

In this cross-sectional clinical study, it was found that two subtypes of CD5+ B-lymphocytes existed either with CD5-high and CD20-low or CD5-low and CD20-high expression, as determined by dual fluorescence analysis with fluorochrome-labeled monoclonal antibodies on a FACScan flowcytometer. In the normal healthy subjects (n = 20), the CD20 positive cells could be broken down into 3 subsets: CD5(2+) CD20+, 25.4 +/- 3.0% (mean +/- S.E.M.), CD5+ CD20(2+), 18.4 +/- 2.4% and CD5- CD20(2+), 56.2 +/- 2.7%. Similar values were observed in a group of patients (n = 29) suffering from a wide variety of benign or untreated malignant disorders. The CD5(2+) CD20+ subset was typically related to age (Spearman coefficient of correlation rho = 0.77, P less than 0.001 in healthy subjects and rho = 0.46, P = 0.02 in pathological cases). The CD5+ CD20(2+) subpopulation was a salient feature of newborns and little infants (n = 6, 75.4 +/- 2.4%, P less than 0.01). The CD5- CD20(2+) subset was characteristically depressed in patients treated with cytotoxics (n = 21, 41.2 +/- 3.6%, P = 0.001). As far as cytotoxic chemotherapy may represent a model of accelerated ageing, it is worth noting that, in patients treated with cytotoxics, the CD5 CD20 pattern was frequently disturbed in a hyperyoung or hyperaged picture. That age and cytotoxics can affect CD5 expression on CD20+ lymphocytes, suggests some specific B-dysregulation and should be put together with the known emergence of autoantibodies, paraproteinemias and lympho-plasmocytic tumors with age and chemotherapy.

Adult

Leukocyte and lymphocyte subsets after a short pharmacological stress by intravenous epinephrine and hydrocortisone in healthy humans.

Nine healthy volunteers received epinephrine and hydrocortisone intravenously in order to assess the typical acute response to a brief stress, of leukocyte and lymphocyte subsets, acute phase reactants and lymphocyte reactivity to T and B mitogens. At 10 min., all leukocyte subsets were increased, especially mononuclear cells. At 1 hour, moderate lymphopenia and monocytopenia occurred. At 6 hours, neutrophilia and eosinopenia were observed. During the lymphocytic early wave, all the lymphocyte subset counts increased, particularly T-suppressive/cytotoxic and natural killer cells. As a consequence, the percentage of T cells decreased and the CD4/CD8 ratio fell. No changes in acute phase reactants occurred over the 24 hours of the study. All leukocyte and lymphocyte subsets were normalized and mitogen reactivity was unchanged 24 hours after the stress. These typical shifts in leukocyte subsets could probe the adrenocortical and medullary response to an environmental stressor.

Acute-Phase Proteins

Nifedipine-induced hyporeactivity in delayed hypersensitivity skin tests.

Four patients and three healthy volunteers were submitted to delayed hypersensitivity skin tests to candidin, tuberculin, streptokinase/streptodornase (SK/SD) and mumps antigen before and after a 1 week treatment with nifedipine 10 mg q. 8h. A decrease in the scores of induration and erythema was observed, especially in response to SK/SD antigen challenge. We conclude that nifedipine may induce an anergy status in delayed hypersensitivity skin tests.

Humans