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Biomedical subjects

P Mares

Publications and source records attributed to P Mares.

At least 199 records · Page 11Linked to original sources
PubMed1991

[Techniques, results and indications of embryonic reductions in multiple pregnancies. Review of the literature].

The authors report, after a review of the literature, the evolution of ideas concerning first-trimester terminations in multiple pregnancies. Different techniques are performed including transabdominal approach or transvaginal approach at the mean gestational age of 9 or 11 weeks of amenorrhea. Analysis of obstetrical results obtained after these procedures (rates of early or late abortions, preterm labor or in utero growth retardation) shows a high rate of abortions and demonstrate also that reductions are unable to prevent premature births. Indications are discussed: concerning pregnancies of high order (four or more), most part of authors agree with the procedure and also when a triplet pregnancy occurs on a scarred or malformed uterus. Concerning triplet pregnancies, the procedure remains considered by some teams as an unethical approach of theses gestations, specially when considering the recent advances in perinatal medicine. In all cases, a clear and complete information about the risks of these procedures should be given to couples faced with multiple pregnancies.

Abortion, Induced↗
PubMed1991

[Intra-conjugal immunotherapy and the pathology of reproduction. Experiences at the Center for the Treatment of Sterility, Montpellier-Nîmes].

81 patients who had consulted for infertility, of whom 26 had recurrent spontaneous abortions (RSA), 28 unexplained infertility (UI), and 27 with difficulties for implantation following in vitro fertilization (IVF) were tested by a cross-match for the presence of the partner's lymphocyte antibodies. When the result was negative, leucocyte transfusions were carried out (200 million of the partner's lymphocytes in 3 successive injections at intervals of one month). Positive antipaternal cytotoxic antibodies were found in 81% of cases. There was, however, no benefit in groups of unexplained infertility or implantation difficulties. In the RSA group there was a 50% recurrence of spontaneous abortions.

Abortion, Habitual↗
PubMed1990

Preparative separation of sphingolipids and of individual molecular species by high-performance liquid chromatography and their identification by gas chromatography-mass spectrometry.

Six fractions containing tri- to pentaglycosylceramides were isolated from the green, fresh water alga Chlorella kessleri, grown heterotrophically, by using preparative high-performance liquid chromatography (HPLC). Up to twelve fractions were obtained by further reversed-phase HPLC of each glycosylceramide. The use of a polar capillary column with Supelcowax 10 as the stationary phase allowed an excellent separation of the individual molecular species of ceramides, even though the separation did not occur when the ceramides differed only in the position of the amide bond. The individual molecular species (even if present in mixtures) were identified by gas chromatography-chemical ionization mass spectrometry. The evidence for a complete structure was obtained by enzyme splitting with alpha- and beta-galactosidases (the sequence of monosaccharides) and by negative ionization fast atom bombardment mass spectrometry. More than 400 molecular species of glycosylceramides were identified.

Ceramides↗
PubMed1990

Pure fetal blood samples obtained by cordocentesis: technical aspects of 322 cases.

Three hundred and twenty-two percutaneous umbilical blood samplings were performed over 4 years in our prenatal diagnostic centre. A 3.5 MHz sector ultrasound transducer was used to guide a 22.5-gauge needle under local anaesthesia. Sampling was performed for rapid fetal karyotyping (within 72 h) in 120 cases, for diagnosis of fetal toxoplasmosis in 133 cases, for determination of the severity of Rh immunization in 15 cases, and for diagnosis of congenital rubella in 4 cases. Pure fetal blood was obtained in 98.7 per cent of the cases after two attempts. The approach to the cord was either transamniotic or transplacental. Puncturing was preferentially done at the placental insertion of the cord (72.2 per cent of the cases) and the mean blood sample volume was 3.5 ml. The rate of fetal death in utero was 1.9 per cent, including two cases of amnionitis, one trisomy 18, and one severe bradycardia. The failures were due to sampling at an early stage of pregnancy (before gestation week 18), to maternal obesity, oligohydramnios, and the inexperience of the operator.

Anemia, Sickle Cell↗
PubMed1990

Excitatory amino acid antagonists and pentylenetetrazol-induced seizures during ontogenesis. I. The effects of 2-amino-7-phosphonoheptanoate.

The anticonvulsant action of 2-amino-7-phosphonoheptanoate (AP7) was assessed during ontogenesis of the rat. Animals of five age groups (7, 12, 18, 25, and 90 days) were pretreated with AP7 i.p. in the doses from 15 to 60 mg/kg 30 min prior to pentamethylenetetrazol (PTZ; metrazol; 100 mg/kg s.c.). The incidence and latency of minimal seizures (pure clonic without the loss of righting ability) and of generalized tonic-clonic seizures (major) were evaluated and compared with the control groups. Minimal metrazol seizures were not regularly observed in controls between ages 7 and 12 days. An increased incidence was noticed in AP7-treated groups. In animals of 18 days of age and older the AP7-pretreatment did not influence incidence of minimal seizures; the latencies were significantly lengthened only in 18-day-old animals. Major seizures were significantly suppressed with the highest dose of AP7 (60 mg/kg) in all groups except 7-day-old rats. In 90-day-old rats all doses of AP7 were effective in the suppression of major seizures. The latencies of major seizures were increased in 7 and 18 days old rats. It appears that the blockade of NMDA receptor substantially influences the major seizures induced by PTZ, whereas minimal (clonic) seizures are affected weakly. This suggests an important role of NMDA receptor-mediated transmission in the genesis of generalized tonic-clonic seizure pattern.

2-Amino-5-phosphonovalerate↗
PubMed1990

Ketamine suppresses both bicuculline- and picrotoxin-induced generalized tonic-clonic seizures during ontogenesis.

An anticonvulsant action of ketamine, a noncompetitive N-methyl-D-aspartate (NMDA) antagonist (5-40 mg/kg IP), on the bicuculline-induced (3-8 mg/kg IP) or picrotoxin-induced seizures (3-6 mg/kg IP) was assessed in male Wistar rats aged 7, 12, 18, 25 and 90 days. Ketamine alone caused moderate ataxia which was more pronounced in younger animals. In combination with both aforementioned convulsants, ketamine exerted anticonvulsant effects against generalized tonic-clonic seizures in all developmental stages studied. This effect was more pronounced in bicuculline-treated animals. Moreover, ketamine also suppressed the lethality induced by both drugs during all the development. On the contrary, the action of ketamine on minimal (clonic) seizures was moderate or absent. Our results suggest an important role of ketamine-affected transmission in the generation of the generalized tonic-clonic seizure pattern; moreover, an action of high doses of ketamine on GABA-A receptors might be present.

Aging↗
PubMed1990

Effects of dietary n-3 fatty acids on the composition of cholesteryl esters and triglycerides in plasma and liver perfusate of the rat.

The effects of polyunsaturated fatty acids of the omega-3 family (PUFA n-3), (addition of fish oil), on the molecular composition of cholesteryl esters and triglycerides in plasma and liver perfusate of rats were studied. Rats fed a diet rich in saturated fatty acids (addition of lard) served as controls. Supplemention with PUFA n-3 not only decreases the plasma concentrations of free cholesterol, cholesteryl esters, and triglycerides, it also significantly alters the plasma composition of cholesteryl esters and triglycerides. Analyses of liver perfusate indicate a decrease in triglycerides secretion by in vitro perfused liver and reciprocal changes in relative contents of cholesteryl esters fractions with C(16) and C(20) acyl chains. This finding may be a result of chain-shortening of long-chain fatty acids probably in peroxisomal beta-oxidative system. Alterations in plasma cholesteryl esters and triglycerides composition of the fish oil group could be affected further by additional factors such as increased plasma cholesterol esterification activity and presence of triglyceride species of intestinal origin.

Journal Article↗
PubMed1990

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↗
PubMed1990

[Cytometric profiles of DNA content in cervical intraepithelial neoplasia (CIN)].

The cervical cytologic screening is responsible for the overall decline in the incidence of cervical cancer. Despite this apparent success, the cytologic assessment by light microscopy of cervical smear has recently been shown to have deficiencies particularly in cervical intraepithelial neoplasia (CIN). Now, this pathology of the uterine cervix is increasingly becoming recognized as a major health problem in young women because of its high frequency and its association with the development of cervical carcinoma. Flow cytometry (FCM) is widely used as a rapid method to analyse DNA content of a great number of cells on a cell by cell basis. The authors have applied FCM to CIN in order to reinforce the cytologic screening of cervical smears. Three abnormal DNA patterns have been observed: increased and heterogeneous DNA pattern; increased S and G2+M phases; abnormal DNA content. The statistical calculation has emphasized the significant relation linking these DNA patterns with the cytologic diagnosis and the severity of CIN. Therefore, FCM is a powerful complementary tool in cervical pathology.

Carcinoma in Situ↗
PubMed1990

Influence of a new antiepileptic drug ORG 6370 on metrazol-induced seizures in rats during ontogenesis.

The anticonvulsant action of a new antiepileptic drug ORG 6370 (Organon International B.V.) was studied in 217 male albino rats aged 7, 12, 18, 25 and 90 days. Epileptic phenomena induced by a subcutaneous injection of a 100 mg/kg dose of metrazol (isolated myoclonic jerk, minimal metrazol seizures and major, generalized tonic-clonic metrazol seizures) were used as a model. ORG 6370 did not influence myoclonic jerks or minimal metrazol seizures in those age groups where they were regularly elicited. In 12-day-old rats pretreatment with ORG 6370 led to the appearance of minimal metrazol seizures, a phenomenon rarely seen under control conditions. Major seizures were suppressed only in adult rats with a 20 mg/kg dose; on the other hand, ORG 6370 exhibited a selective action against the tonic phase of major seizures at all stages of development. The profile of action of ORG 6370 is almost the same as that of phenytoin.

Animals↗
PubMed1990

Localisation of the origin of self-sustained after-discharges (SSADs) in the rat: the serrated wave (SerW) type of SSAD.

The self-sustained after-discharges (SSADs) characterised by the EEG pattern of serrated waves (SerW) were induced by rhythmic low frequency electrical stimulation of thalamic nuclei and the hippocampus of Wistar albino male rats in acute experiments. We used spreading depression to eliminate functionally the cortex and the hippocampus. Suction ablation of the cortical somatosensory projection area was also used to test its involvement in the SerW SSAD induction. The hippocampal spreading depression but not the cortical one abolished the SerW SSAD induced by the stimulation of the thalamic nuclei. The animals with the suction ablation of the somatosensory projection area also produced SerW SSADs when the stimulation electrodes were placed in the thalamic ventrobasal complex (in intact animals this stimulation induces spike-and-wave SSADs but not SerW-SSAD). The crucial importance of the hippocampus in the SerW SSAD generation and its possible use as a model of partial seizures with complex symptomatology is discussed.

Animals↗