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Biomedical subjects

R Gandar

Publications and source records attributed to R Gandar.

At least 19 recordsLinked to original sources
PubMed1991

[The corpus luteum and progesterone secretion].

The pulsatility of LH secretion has been known only since 1970. The pulsatility of progesterone secretion has now also been shown. The frequency and amplitude of these pulses vary during the three phases of the luteal period. The first or early luteal (EL) phase lasts four days starting from the peak of LH. There is no pulsatility of progesterone during EL. The frequency of LH pulsatility is 103 +/- 8 minutes. The second or mid luteal (ML) phases, from +6 to +9 days after the peak of LH, is characterised by pulses of LH and of progesterone, most often in positive crossover correlation and with 7 to 14 pulses per 24 hours. The frequency of LH pulsatility is 166 +/- 33 minutes according to Filicori. The amplitude of LH secretion is 4 to 40 ng/ml. The third or late luteal (LL) phase, occurring at +11 days before the menstrual period, has the same characteristics in terms of quality but shows variations in frequency and amplitude towards a decrease. Thus the amplitude of progesterone secretion is 2.8 to 9 ng/ml (Veldhuis). In the opinion of clinicians, the corpus luteum is independent up to LH+ 5 days. The injection of hCG during this time is ineffective. A single progesterone level is sufficient if the result is 10 ng/ml or more. The problem remains complex concerning results below 10 ng/ml. The solution suggested for the present is that described by Olive: during ML and/or LL, three samples in the morning at hourly intervals and two endometrial biopsies during two consecutive cycles.

Biopsy↗
PubMed1988

[Premature failure of the ovaries].

The premature ovarian failure syndrome has been reviewed on the basis of existing data. The frequency, clinical picture and diagnostic procedures of premature ovarian failure are discussed. The disorder is characterized by secondary amenorrhea with constant estrogen deficiency and elevated gonadotropin levels in the post-menopausal range. Differential diagnosis is to be made with pituitary adenomas secreting gonadotropin, circulating gonadotropin antibodies, and biological profiles typical of the peri-menopausal years. Histopathology distinguishes two principal forms of premature ovarian failure: the premature menopause with complete follicular depletion of the ovaries, and the insensitive ovary syndrome. A correct ovarian biopsy is important for this diagnosis and can also help to point toward an immunological etiology. The following causes of premature menopause are analysed: chromosomal abnormalities, autoimmune disorders, viral infections and galactosemia. The toxic and iatrogenic causes are not developed. The factors eventually implicated in the insensitive ovary syndrome are discussed: deficient biological activity of gonadotropins, the presence of inhibitor substances preventing hormone action and the presence of antibodies toward FSH receptors. In the management of premature ovarian failure, a possible autoimmunization has to be considered. When an immunological disorder is suspected, other autoimmune glandular failures, that may develop secondarily, have to be detected. From the 26 pregnancies reported after a diagnosis of the insensitive ovary syndrome, only two occurred after a correct ovarian biopsy. Those cases seem to indicate that reducing endogenous gonadotropins to normal levels is important before considering induction of ovulation.

Adult↗
PubMed1987

[Risk factors in cancer of the endometrium].

The authors evaluate the incidence of the main risk factors in endometrial cancer by comparing a continuous series of 101 patients with a matched reference series. Among these factors, obesity and multiparity are significantly more frequent in patients with endometrial cancer. All of these risk factors are related to a hyperestrogen level. Their knowledge may contribute to a policy of prevention of endometrial cancer, but does not permit its screening by limiting to women presenting these risk factors.

Adult↗
PubMed1986

[Value and indications for nipple stimulation in obstetrics].

The authors have evaluated the effect of stimulation of the breast on uterine tone in a series of 25 patients at term where induction of labour was indicated for obstetric reasons. In 64% of cases breast stimulation carried out for 30 minutes was followed by uterine contractions. In 20% of these cases the authors found that the uterus contracted strongly and in two patients so strongly as to cause fetal heart slowing. Breast stimulation matures the cervix slightly but this is not statistically significant for Bishop's score. In 16% of case breast stimulation provoked labour. Analysing these results and studying the literature shows that the effect is linked to the degree of cervical maturity at the onset and the effect of stimulation depends also on the length of time the stimulation was carried out. In practice the use of breast stimulation is limited because of the risks of hypertonic contractions and this is turn requires careful fetal heart monitoring.

Adolescent↗
PubMed1985

[Cytological detection of cancer of the cervix uteri].

In spite of the apparent simplicity in detection of dysplasias (cervical intraepithelial neoplasias or CIN I, II, or III) and cancer of the cervix, numerous epidemiologic, biochemical, cytologic and socioeconomic problems are involved. The purpose of this early detection is unquestionably sound, even if the efficiency seems not to achieve high levels in accordance to expectations concerning results and if the cost of reiterated cervical and vaginal scraping smears seems exorbitant. The financial constraints and some cost-effectiveness analyses have promulgated use of longer intervals between cytologic exams (Pap tests). Such an attitude is only acceptable if an improvement in quality and sensitivity of detection is likewise established: other factors such as variable biologic development of epithelial lesions of the cervix must be taken into account; and consideration of cytologic sensitivity of early detection with the difficulties encountered in definition and identification of groups of women at risk. The longer spread between Pap smears exposes some women to the danger of non-detection of certain dysplasias (CIN I, II, or III), rapidly developing carcinomas, and so they lose out on the benefits of an early diagnosis, limited, effective, and less expensive treatment.

Adolescent↗
PubMed1985

[The effects of the pulsatile administration of naloxone on the secretion of gonadotrophins in a case of hypothalamo-hypophyseal amenorrhea].

12 mg of Naloxone were given using an intravenous pulsatile pump at the rate of 0.4 mg/minute every 8 minutes over a period of 4 hours in a woman of 28 years of age who had secondary amenorrhea of hypothalamic origin. The levels of L.H., F.S.H. and Prolactin were calculated every half hour during and after the perfusion. These was a progressive rise in the amplitude of L.H. peaks but no changes in F.S.H. and Prolactin levels. Intermittent inhibition of endogenous opioids seems to re-establish the pulsatile secretions of the hypothalamo-pituitary axis.

Adult↗
PubMed1984

[Protein binding of steroids].

The role of protein-binding in the physiology of steroids is of great complexity. The following are envisaged: the types of protein, methods of binding and the affinity of steroids for proteins, and the variations in free fraction according to plasma protein levels; the functions of binding proteins on the activity and clearance of steroids as well as on the peripheral conversion of androgens; the factors which influence variations in binding protein levels and in particular the influence of circulating levels of natural hormones and the influence of hormone treatment.

Adult↗
PubMed1984

[Changes in LH, FSH, PRL and estradiol after perfusion with naloxone in normal and amenorrheic women].

Naloxone is antagonistic to endogenous opioids. Giving it shows that these opioids act as controlling mechanisms in the secretion of LH and FSH by the hypothalamic, pituitary system and probably of Gn-RH by the hypothalamus. Endogenous opioids and particularly beta endorphin, which is itself under the control of oestradiol, play an inhibitory role on the secretion of Gn-RH and alter the pulsatile mode of Gn-RH secretion. We could not demonstrate PRL action which has been described by other authors.

Amenorrhea↗
PubMed1983

[Hemoglobin A1c and its variations in pregnancy].

Variations in haemoglobin A1c were studied at different stages of pregnancy in 306 non-diabetic women, using a specific method. It was found that HbA1c levels progressively decreased during the first 25 weeks of pregnancy, then remained stable. No correlation was noted between carbohydrate metabolis and Hb A1c levels. The new assay provides additional information on glucose tolerance in pregnant women and could be used to detect gestational diabetes.

Adult↗
PubMed1982

[Treatment of menopausal hot flushes with a nonhormonal medication, veralipride].

The value of veralipride in menopausal disorders is no longer questionable and has been documented by a number of studies. The purpose of this paper is to study the clinical effectiveness and to look for the biological consequences of three months therapy with veralipride. To achieve this, a thorough biological study (hematology, glucids, lipids, hepatic and renal function) was done in 21 patients with a menopausal syndrome before and after taking veralipride for three months. Clinical effectiveness was excellent with 80% satisfactory results. No signs of intolerance or adverse side-effects were seen. We recorded no significant changes in biological parameters. No disturbances of renal or hepatic function were detected, either in individual assessments or in the overall statistical analysis of the study group. Because it is well tolerated, effective, and devoid of adverse metabolic side-effects, we conclude that veralipride is the best non-hormonal treatment for menopausal disorders presently available.

Climacteric↗
PubMed1982

[Maternal glucose tolerance along pregnancy (author's transl)].

The development of the foetal and placental unit induces large changes in maternal glucose tolerance along pregnancy. Oestrogen-induced hyperinsulinism is responsible for facilitated anabolism which take place during the first part of pregnancy. Accelerated catabolism occurring during the second part is due to the direct action of placental hormones, mainly of human placental lactogen. The latter is responsible for diminution of peripheral insulin activity. Hyperinsulinism, which is very important at this stage, facilitates an intense and rapid anabolism, mainly in the liver from where nutriments can be easily removed. Glucose and amino-acid uptake by placental and foetus are greatly increased by all these changes.

Blood Glucose↗
PubMed1982

[Infertility and carbohydrate metabolism. A study of 93 cases (author's transl)].

An oral glucose tolerance test was performed in 93 women with unexplained infertility (sterility or repeated abortions). An abnormal carbohydrate metabolism was found in 1/3 of the cases (32 patients). Advice on diet control, provided to all of these patients, was followed only by 13.9 of these, who conceived less than 6 months after initiation of the low carbohydrate diet, achieved full-term pregnancy. These results suggest a relationship between infertility and glucose intolerance. A glucose tolerance test should be performed in all women presenting unexplained infertility.

Abortion, Habitual↗
PubMed1979

[The oral glucose tolerance test during normal pregnancy (author's transl)].

Physiological changes in carbohydrate tolerance were studied between the beginning and end of pregnancy. Amongst 145 oral glucose tolerance tests performed between the 9th and 40th weeks, results indicated that carbohydrate tolerance evolved throughout pregnancy. The first 24 weeks were characterised by a change in the shape of the glucose tolerance curve, in the form of horizontalisation of the terminal part, but with no increase in early blood glucose figures. It was only after the 24th week that mean blood glucose levels were seen to be increased. The interpretation of glucose tolerance tests during pregnancy should take these physiological changes into account. Critical values, above which diabetes must be suspected, are different at the beginning and end of pregnancy. The critical point would appear to be around the 24th week.

Adult↗
PubMed1979

[Screening for diabetes during pregnancy (author's transl)].

Screening for diabetes, or more commonly the study of maternal glucose tolerance, a routine procedure during pregnancy. The first step consists of assessing the diabetic risk for the patient. Screening tests should be applied early if risk factors for diabetes are present, and/or at a later stage in all pregnant women. The initial test should always be provoked hyperglycemia by the intravenous route. According to the value of the glucose assimilation coefficient K, the test will be repeated using the oral route. Screening can only be effective if applied to all pregnant women.

Administration, Oral↗