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Biomedical subjects

F Arnal

Publications and source records attributed to F Arnal.

At least 55 records · Page 3Linked to original sources

Studies on new, centrally active and reversible acetylcholinesterase inhibitors.

We have synthesized the tertiary amines of pyridostigmine and neostigmine, 3-pyridinol dimethylcarbamate (norpyridostigmine) and 3-dimethylaminophenol dimethylcarbamate (norneostigmine) respectively, and we have tested their abilities to cross the blood-brain barrier and inhibit mouse brain AChE activity. The in vivo inhibition of AChE activity by norpyridostigmine reaches 72% at 10 minutes which is comparable to that seen with physostigmine (73% at 10 minutes). Inhibition by norneostigmine is less effective (50% at 10 minutes) and approaches that obtained with tetrahydroaminoacridine (57% at 10 minutes). These data show that both norpyridostigmine and norneostigmine cross the blood-brain barrier and that they are effective inhibitors of mouse brain AChE activity. These drugs could be useful in the treatment of memory impairment associated with Alzheimer's disease, and other memory disorders.

Acetylcholinesterase↗

Early or late monitoring of stimulation of ovulation for in-vitro fertilization? A methodological discussion of a randomized study.

Two GnRH agonist long-stimulation protocols, in association with HMG, are compared on a random basis. Group A (n = 53) was monitored daily from the 6th day of stimulation, whereas monitoring in group B (n = 55) began on the 11th day of stimulation. There was no significant difference in the numbers of follicles which matured, the numbers of collected oocytes, the numbers of embryos obtained in vitro and the clinical pregnancy rate. But the power of such a study is very weak (6%). It would have been necessary to include greater than 1000 patients in each group to obtain a bioequivalence test. Such a study is unrealistic for a single centre and multicentric studies are very difficult to achieve because of practical difficulties. A pooled analysis is perhaps the methodological answer.

Chorionic Gonadotropin↗

Obstetrical results after embryonic reductions performed on 34 multiple pregnancies.

Thirty-four women with multiple pregnancies (three or more fetuses) underwent embryonic reduction in order to reduce abortions, premature births or fetal growth-retardation by obtention of twins. Four early abortions occurred. Thirty pregnancies reached term and out of 60 fetuses, 58 infants were born alive. Fetal death in utero of one twin occurred in two pregnancies. The mean term until delivery was 36 +/- 2.8 weeks gestation and the prematurity rate was 51.7%. Of 55 neonates, 25 were underweight within the 10th percentile and 10 out of 55 neonates were underweight below the 3rd percentile. There were three deaths in the early neonatal period. The rate of perinatal mortality was 8.3%. Fifty-four children are currently healthy and one child has a mild axial hypotonia. A reduction in prematurity was observed with a gain of 2 weeks on reported data concerning triplet pregnancies. The rate of low-birth-weight infants was high, 63.5% being underweight at birth.

Abortion, Incomplete↗

Results of IVF attempts in patients with unexplained infertility.

From January 1986 to July 1987, 143 patients with unexplained infertility (UI) following 217 IVF attempts were studied and randomly assigned for statistical analysis to be compared with 434 tubal infertility (TI) patients undergoing 748 IVF attempts. The age of patients, previous pregnancy history and stimulation protocols were identical in both groups. In comparison with tubal patients, IVF attempts on the UI group were characterized by the same rates of cycle failure, mean number of oocytes retrieved per cycle, a lower fertilization rate (45.7% UI/59.8% TI) (P less than 0.01) and no difference in cleavage and nidation rates. However, a decrease in the pregnancy rate/attempt (13.8% UI/19.5% TI) tended towards a significant value (P = 0.06). Although the semen parameters were found to be in the normal range during the previous fertility screening in both groups, the incidence of at least one abnormality (count less than 20 X 10(6)/ml, and/or total motility less than 30% and/or abnormal forms greater than 75%) on the day of insemination was found to be significantly higher in UI (20%) than in TI (11%) patients. Moreover, 25% of UI patients did not fertilize any oocytes inseminated, whatever the number of oocytes retrieved. This rate of failed fertilization was significantly lower (9%) in tubal patients. The oestrogen response profiles were similar in both groups, analyzed according to the stimulation protocols.(ABSTRACT TRUNCATED AT 250 WORDS)

Buserelin↗

[Use of a technic of bioluminescence for determining estrogens and LH during static and dynamic study of the ovary].

Estrogens and LH are necessary among other assays for ovulation diagnostic and ovarian monitoring during stimulations. They can be both measured with a method based on a bioluminescent reaction. This method measures, with a standard luminometer, the reduced NAD produced and accumulated by the reaction of two dehydrogenase enzymes: the estradiol dehydrogenase for direct assay of estrogens (estrone + estradiol), the glucose-6-phosphate dehydrogenase for gonadotrophin determination. These techniques can be applied to all biological fluids. They are simple and straightforward, do not need extraction and can be automated. Urinary assays are very useful in clinical practice to appreciate ovarian function, either during a spontaneous cycle or under stimulation, and are mandatory to decide the timing of hCG injection. The reported studies can be listed as follows: determination of preovulatory LH rise (LH greater than 10 Ul/g of creatinine) prior to embryo transfer after cryopreservation and thawing, detection of LH surges during ovarian stimulation, either premature surges causing premature luteinization, either normal surges when follicular maturation is adequate (296 cycles), confirmation of pituitary desensitization when using GnRH agonists (43 cycles), study of the initial stimulatory effect of GnRH agonists (13 patients). This effect can be responsible for the inadequate results obtained with the so-called "short protocol" in this experience when compared with the "long protocol" in the author's experience with compared with the "long protocol" (8 p. cent pregnancy rate per stimulation cycle versus 20 p. cent respectively, intrafollicular LH in 129 follicular fluids (86 with GnRH agonists and 43 without) has no correlation with the fecundability of the ovum. These results lead to extend bioluminescent techniques to the study of other parameters, and in particular FSH.

Buserelin↗

Infection by Mycobacterium avium intracellulare in AIDS: endoscopic duodenal appearance mimicking Whipple's disease.

We report the case of a 24-year-old woman who presented with diarrhea, weight loss and abdominal lymph node enlargement. A diagnosis of infection by Mycobacterium avium intracellulare with a clinical picture similar to Whipple's disease was established. The endoscopic study of the duodenum revealed multiple yellow nodules that became confluent in the second portion, entirely replacing the normal mucosa. These endoscopic findings have not been described previously in intestinal infection by Mycobacterium avium intracellulare.

Acquired Immunodeficiency Syndrome↗

Santorinirrhage: hemosuccus pancreaticus in pancreas divisum.

We describe a previously unreported complication of pancreas divisum: severe and repeated episodes of gastrointestinal bleeding through the main pancreatic duct (hemosuccus pancreaticus) in a 34-yr-old woman over a period of 10 months. She had negative investigations, including a blank laparotomy, until an endoscopic retrograde cholangiopancreatography revealed a pancreas divisum with chronic pancreatitis and a small pseudocyst at the tail of the dorsal pancreas. During the procedure, bleeding through the papilla minor was observed coming from Santorini's duct. A corporocaudal pancreatectomy was done and the bleeding episodes have subsided.

Adult↗

Recurrent abnormal follicular maturation and ovarian stimulation for in-vitro fertilization.

A total of 1078 cycles were stimulated for in-vitro fertilization between 1 January 1986 and 31 July 1987. One-hundred-and-ninety-six cycles had to be cancelled because of an abnormal ovarian response (18.2%). The majority of these cancellations were due to the phenomenon of follicular atresia (45%) or the absence of follicular growth (30%). Bad responder patients who had undergone cancellation during at least two successive cycles, when compared with normal responder patients, were somewhat older and had more frequent periovarian adhesions and ovulatory defects. The use of a GnRH agonist allowed correction of a certain number of ovarian response inadequacies, but follicular atresia and absence of folliculogenesis remained frequent phenomena.

Adult↗

Significance of the changes in plasma amino-acid levels in meningococcal infection.

A series of patients with meningococcal infections have been studied and divided in two groups: Group I patients with meningococcal sepsis and group II, those with meningococcal meningitis. Patients in group I presented with more severe encephalopathy, shock, DIC and acute systemic complications. Both groups showed a marked hypoaminoacidemia compared with normal controls (other than for the sulfur containing amino acids and phenylalanine). The concentration of aromatic and basic amino acids, the phenylalanine/tyrosine ratio, the transaminase levels and the negative nitrogen balance were higher in group I patients. The ratio of branched chain to aromatic amino acids was lower in group I. All these differences were statistically significant. The close association between the metabolic derangements and clinical manifestations may help in the understanding of several physiopathological aspects of meningococcal infections.

Adolescent↗

Ovarian stimulation by a combination of a gonadotropin-releasing hormone agonist and gonadotropins for in vitro fertilization.

In the first of two studies, 20 patients were selected on the basis of tubal infertility and were randomly assigned to two groups receiving different ovarian stimulation protocols. In group A, 10 patients were given follicle-stimulating hormone (FSH), FSH was continued until the criteria for human chorionic gonadotropin (hCG) administration were satisfied. In group B, 10 patients received Buserelin (0.3 ml twice a day subcutaneously) for 14 days to induce pituitary desensitization. Stimulation with FSH was then started, and Buserelin treatment was continued until hCG administration. In the second study, patients were included if they had had at least two previous attempts at ovarian stimulation that failed to reach the stage of follicular aspiration. Ovarian stimulation was conducted with a combination of Buserelin and human menopausal gonadotropin. Use of the gonadotropin-releasing hormone (GnRH) agonist in in vitro fertilization increased the number of oocytes collected, the fertilization rate, the length of the luteal phase and the pregnancy rate. The GnRH agonist also contributed to a generally better ovarian response in patients whose estradiol production had previously responded poorly to conventional ovarian stimulation protocols.

Adult↗

Follicular steroids in relation to oocyte development and human ovarian stimulation protocols.

Oocytes of pre-ovulatory follicles were collected by laparoscopy for in-vitro fertilization in 118 women. Patients were treated either during the natural cycle, or after induction of ovulation with clomiphene citrate, or with human menopausal gonadotrophin (HMG), or clomiphene citrate combined with HMG. The oestrogens (oestrone + oestradiol) and total aromatizable androgens (androstenedione, testosterone and dehydroepiandrosterone and its sulphate) were assayed in follicular fluids using an enzymatic method. The levels of progesterone, 17 alpha OH-progesterone, thromboxane, and prostaglandins (PGE2 and PGF2 alpha) were determined by radioimmunoassay. The best follicular fluid indicator of oocyte fertilization in vitro was the A/E ratio, which was less than 1 when the oocyte was fertilized in vitro and led to a pregnancy. The lowest value for the A/E ratio was obtained with spontaneous ovulation protocols. Regardless of oocyte development, the progesterone level was always greater than 2000 ng/ml, and the PGE2/PGF2 alpha ratio was greater than 1 in all stimulated cycles. Our investigations show that a combination of clomiphene citrate and HMG provides the best stimulation, on the basis of follicular fluid analysis and the outcome of fertilized oocytes.

Androgens↗

Pedicled scapular apophysis transplantation. Growing grafts studied in dogs.

Twenty-eight immature dogs, divided into three groups, have been studied to determine the possibilities of pedicled epiphyseal transplantation from a rarely used donor site area, the scapula. One group of 8 immature dogs were studied anatomically using India ink and Batson's compound injection methods. We identified the vascular pattern of the diaphyseal portion of the graft, consisting of the lateral crest or border of the scapula. In two groups of 10 immature dogs, this area was used as a pedicled island graft to rebuild the semiresected or totally resected proximal humerus. There were marked differences between these two groups on the basis of morphologic, histologic, histochemical and electron microscopic aspects of the samples. Preservation of normal growth appeared to be directly related to the compressive forces applied to the graft. Preservation of the cartilage was also related to the biomechanical situation; fibrocartilage and signs of arthrosis were noted 1 year after the operation in several animals whose humeri had been fully subjected to normal stresses. Both the diaphyseal and epiphyseal areas had increased one- to fivefold in volume, but longitudinal growth was markedly deficient.

Animals↗

[Stimulation of ovulation by pure FSH for in vitro fertilization. Study of the route of administration].

Pulsatile injection of FSH to stimulate ovulation for in vitro fertilization was undertaken in order to compare the intramuscular route with the pulsatile subcutaneous route in two groups of 6 patients each selected at random. The patients were selected in such a way as to reduce as far as possible the parameters that would make it difficult to interpret the results. Both from the point of view of the numbers of patients who responded to stimulation of ovulation as well as the numbers of pregnancies that were obtained, the intramuscular route seems to be preferable.

Adult↗

Ultrastructural aspects of nerves, bones, and vessels in hereditary sensory neuropathy.

This study concerns two children, from the same otherwise normal family, presenting progressive spontaneous amputations of the limbs, suggesting peripheral hereditary sensory neuropathy. Samples from the distal nerves and vessels and the distal tibial epiphyses were examined ultrastructurally. The nerves showed signs of degeneration, and a typical bone necrosis, without osteoclasts, was observed in the 2 cm margin of the samples. Simultaneous modifications of the vessels suggest a neurally initiated vascular reflex resulting in bone destruction. Theories that might explain the observations are discussed.

Arterioles↗