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Biomedical subjects

J Lefebvre

Publications and source records attributed to J Lefebvre.

At least 127 records · Page 7Linked to original sources
PubMed1989

Altered erythrocyte cation permeability in familial pseudohyperkalaemia.

1. Erythrocyte cation transport pathways have been investigated in a family with pseudohyperkalaemia. 2. Ouabain- and bumetanide-resistant Na+ and K+ effluxes in three pseudohyperkalaemic patients were not different from those of control subjects when assessed at 37 degrees C. 3. When the temperature was decreased to 20 degrees C and 9 degrees C, K+ passive permeability markedly increased and Na+ permeability remained unchanged in these patients. In contrast, in control subjects a reduction in temperature caused a marked reduction in Na+ and K+ passive permeability. 4. These findings could account for the marked increase in plasma K+ concentration observed at subphysiological temperatures. 5. The Na+-K+ co-transport pathway was reduced in all members of the family, but the Na+-K+ pump was reduced in only two of them. These alterations were independent from the pseudohyperkalaemic state.

Aged↗
PubMed1989

Possibilities and limits of the medical treatment for primary hyperparathyroidism.

Clinically obvious primary hyperparathyroidism is only curable by surgery. Medical treatment is debatable under other circumstances: mild chronic hypercalcemia, patients who refuse surgery, serious coexisting medical problems and recurrence or persistence of PHPT after surgical treatment. Prior to medical treatment, the usual common management of any mild hypercalcemia must be taken. The potential medical treatments are: (1) the inhibition of parathyroid hormone (PTH) secretion, and (2) the inhibition of the effects of PTH. The substances of these two main types are successively described. Nevertheless, no ideal medical treatment of PHPT is actually available.

Amifostine↗
PubMed1989

[Changes in the glucose tolerance parameters in non-diabetic hypertensive patients treated with cicletanine].

The effects of cicletanine hydrochloride on glucose tolerance parameters were studied in a two-phase trial in which patients received a placebo for 2 weeks, followed by cicletanine 50 mg/day for 3 months. Ten patients with mild to moderate hypertension, who were neither obese nor diabetic and had no disorder of glucose tolerance entered the study. None of the patients was withdrawn. Glucose tolerance was evaluated by two oral glucose tolerance tests performed at 90 days' interval, each with half hourly blood glucose and insulin assays. The clinical effectiveness of the drug was assessed by monthly blood pressure measurements. No significant change in glycaemia and insulinaemia was observed. There was a significant decrease of supine SBP from 170.7 +/- 9.1 mmHg to 150.3 +/- 6.7 mmHg (p less than 0.0001) and of supine DBP from 101.3 +/- 4.1 to 80.3 +/- 7.7 mmHg (p less than 0.0001). At the end of the study, 9 of the 10 patients had normal blood pressure values. No undesirable clinical or biochemical effect was noted. thus, cicletanine, an antihypertensive drug derived from furopyridine, proved to be devoid of adverse effects on glycoregulation and clinically effective on hypertension.

Adult↗
PubMed1989

[Enkephalin-like immunoreactivity in Leydig cell tumor].

So far, the presence of an enkephalin-like immunoreactivity has never been reported in Leydig cell tumors at our knowledge. A 39 years old man having a painful gynecomastia and an impotency changing in time has been studied. At clinical examination, he was normal, without palpable testis tumor. The sperm count analysis showed an oligoastheno-spermia. Plasma testosterone (T) was low and plasma estradiol (E2) was high, varying from day to day. T/E2 ratio was always low (20 to 72 - N:220-240) and fell after HCG administration. Plasma LH was normal and plasma FSH was low. 17 hydroxyprogesterone (17 OH-P)/T ratio was increased (0.7 - N:0.23). A small tumor was localized in the left testis by ultrasonography. The spermatic vein catheterization, which was only possible on the left side, showed a decreased T, a high E2 and a low T/E2 ratio (19 - N:304). After unilateral orchidectomy, the histological study confirmed the diagnosis of Leydig cell tumor. With antibodies raised against synthetic Met-en-kephalin, it has been possible to detect an enkephalin-like immunoreactivity in the tumoral cells as well as in the surrounding normal cells.

Adult↗
PubMed1988

Assay of GCDFP-15 by ELISA: an available method for in vitro studies of functional differentiation in human breast cancer.

An enzyme-linked immunosorbent assay (ELISA) was applied to a light protein, isolated from human breast cyst fluid (BCF) termed "gross cystic disease fluid protein - 15 Kda" (GCDFP-15), a potential differentiation marker in in vitro human breast cancer studies. The detection limits of this procedure, performed in microtiter plates, were 0.5 to 250 ng/well corresponding to 10 ng/ml to 5 micrograms/ml of sample or antigen solution. Possible cross-reaction with various antigens, especially those found in culture media, were investigated. The correlation coefficient between enzymoassay and radioimmunoassay was 0.978. The results showed that quantification of GCDFP-15 by ELISA is a specific and highly sensitive method. This procedure may be of interest in in vitro studies on the functional differentiation of breast cancer cells.

Apolipoproteins↗
PubMed1988

Comparison of three techniques for detection of Chlamydia trachomatis in endocervical specimens from asymptomatic women.

Culture in DEAE-dextran-treated HeLa 229 cells, a solid-phase enzyme immunoassay (EIA) (Chlamydiazyme; Abbott Laboratories, North Chicago, Ill.), and a direct immunofluorescence test (DFA) (MicroTrak; Syva Co., Palo Alto, Calif.) were compared for the detection of Chlamydia trachomatis in endocervical specimens from 715 asymptomatic women. Response to antibiotic therapy was also monitored at least 4 weeks after completion of therapy. An additional sample was collected at a control visit, and a second culture was performed if discrepancies were observed between the three tests. A total of 48 infections were diagnosed, for a prevalence of 6.7%. At the first visit, 37 specimens were positive by culture. The respective sensitivities of EIA and DFA were 78.4 and 81.1% and the respective specificities were 96.8 and 97.9% when compared with the cell culture technique. The positive predictive values were 56.9 and 68.2%, respectively. When the additional 11 infections detected by the second culture were included to establish a new standard of positivity, the sensitivity of the first culture was estimated at 77.1%. The positive predictive values of EIA and DFA increased to 77.6 and 83.7%, respectively. EIA and DFA performed as well as culture for control of therapy; a 100% agreement among the three techniques was observed.

Adolescent↗
PubMed1988

Characterization of catecholestrogen membrane binding sites in estrogen receptor positive and negative human breast cancer cell-lines.

A specific membrane-binding of an estradiol metabolite, the catecholestrogen (CE) 2 hydroxyestrone (2OH-E1), was demonstrated in two receptor-positive (MCF7 and VHB1) and one receptor-negative (MDA-MB-231) human mammary carcinoma cell lines. The three cell lines were found to be able to synthesise and inactivate CE. Solubilization of membrane bound CE results in a high molecular weight component whose specificity differs from that of the classical estrogen receptor. Apparent dissociation constants were 6-10. 10(-9) M and binding capacities were higher in the receptor-positive cell lines than in the receptor-negative one. Since CE are susceptible to rapid degradation, the presence of such a site may be relevant in the protection and concentration of 2OH-E1 which has been shown to have "in vitro" anti-estrogenic properties in MCF7 breast tumor cells.

Binding Sites↗
PubMed1988

[Early prediction of the magnitude of seasonal variations in testicular diameter and percentage of abnormal spermatozoa in Ile-de-France rams. 1. Animals born in February].

The aim of this study, conducted in spring born animals, was to analyse if within a group of males of the same age, there is any relationship between the testis diameters (TD) or between the percentages of morphologically abnormal spermatozoa (AS) recorded in the same animal at two periods of its life (be it at two different spring periods or at two stages of its age: ram lamb and adult). Eighteen Ile-de-France ram lambs born in February 1980 and issued from five adult rams whose seasonal variations in TD and AS had been followed for two consecutive years were used in this study. Semen was collected (artificial vagina, 1 ej/male/wk) from October 1980 until December 1983 (slaughter of the animals) every semester during "Periods" (n = 7). Within a same year, the first semester (February to June) was called "Spring", the second (August to December) "Autumn". AS (150 cells/smear) were controlled on each ejaculate and the same week maximum TD of both testes was measured using a calliper. Correlations were calculated for TD and AS between individual values (simple correlations) or between groups of individual values (multiple or canonic correlations) at different periods. These values were chosen as follows: TD: 4th and 5th control for the first period (P1, ram lamb); the three lowest values recorded in April (P2, P4, P6); the three mean highest values recorded in Autumn (P3, P5, P7). AS: the first five measurements in P1; the four highest percentages obtained in March-April in P2, P4, P6 (correlations were not calculated in autumn since AS were very few). 1 a: On the whole, TD increased with the age of the animal until 24-27 months and passed alternatively by minimal (February to April) and maximal (September) values each year. Testis growth due to the effect of photoperiodism started every year in the first days of June. 1 b: Except alterations of semen quality in August 1983 (due to high local temperatures), AS were always higher in Spring than in Autumn, maximal values being reached in February (P4) or in March-April (P2 and P6). Their seasonal variations were thus opposed to those of TD (r = -0,671 between weekly means of AS and TD of the whole group of animals from P2 to P6). II-TD: Individual TD of ram lambs were significantly correlated with those recorded in the same adult animal (P1-P2, P1-P6, but P1-P4 NS) especially in autumn (P1-P3, P1-P5, P1-P7.

Animals↗
PubMed1987

Prognostic significance of prolactin receptors in human breast cancer.

Overall survival and relapse free survival (RFS) were studied in 547 patients according to the presence of prolactin receptors (PRL-R), either free or total (after 3 M MgCl2 desaturation). All these patients were surgically treated for locoregional disease in the same institution between 1978 and 1984. In actuarial survival studies, RFS was higher in total PRL-R positive patients in the whole population (P less than 0.02). When the population was divided into two groups, according to either the presence or the absence of node metastasis or the presence or absence of estradiol receptor, the higher RFS was restricted to node positive (P less than 0.001) and to estradiol receptor positive patients (P less than 0.01). The Cox analysis on RFS showed that free PRL-R alone was a significant prognostic factor in estradiol receptor positive patients; total PRL-R alone was never significant; when considered together with steroid receptors, free as well as total PRL-Rs were significant prognostic factors in some subgroups of patients.

Breast Neoplasms↗
PubMed1987

[Blood amylase and lipase in diabetic ketoacidosis].

The relation between increase of amylasaemia and increase of lipasaemia was studied during ketoacidosis in 31 insulin-dependent diabetics. The effects of metabolic disturbances on amylase production during the acute phase of ketoacidosis were also evaluated. The greatest increase of amylasaemia was observed after 24 hours in 17 cases (55%), with return to normal values after 3 to 7 days. Amylasuria was closely correlated with amylasaemia (r = 0.7; P less than 0.01). No correlation was found between hyperamylasaemia and the degree of ketoacidosis, but there was a correlation between plasma osmolality and hyperamylasaemia (r = 0.44; P less than 0.02). The increase of lipasaemia, considered more specific of pancreatic damage, was closely correlated with that of amylasaemia (r = 0.63: P less than 0.01). The electrolyte disturbances associated with ketoacidosis are responsible for cellular damage with release of enzymes in many tissues. The hyperamylasaemia consecutive to pancreatic damage might be of similar origin and aggravated by splanchnic hypoperfusion.

Acute Disease↗