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Biomedical subjects

M Vial

Publications and source records attributed to M Vial.

At least 19 recordsLinked to original sources

Laparoscopic pericystectomy for liver hydatid cysts.

BACKGROUND: The laparoscopic approach for managing of liver echinococcosis is a controversial issue because of scarce experience worldwide. The aim of this report is to describe the technical details of our laparoscopic method and present our results. METHODS: Consecutive cases of liver echinococcosis managed by laparoscopic surgery are reported. Thoracic x-ray and abdominal ultrasound had been performed previously. The following aspects were considered as selection criteria: unique cyst located in segments III, IV, V, VI, and VIII; diameter less than 7 cm; and no evidence of infection or calcification. An evacuating puncture was performed, germinative membrane removed, and pericystectomy performed, which extirpated the pericystic structure with the surrounding liver parenchyma. Specimens were removed in a plastic bag through one of the ports. Surgical morbidity, hospital stay, time until return to work, and evidences of hydatid recurrence were measured. RESULTS: Surgery was performed on eight patients (5 women and 3 men) with a mean age of 44.9 years (range, 22-83 years) who had a liver hydatid cyst with a mean diameter of 6.6 cm (range, 5-7 cm). During a mean follow-up period of 30 months (range, 23-44 months), no morbidity or hydatid recurrence were verified. Hospital stay was 2 days in all cases, and return to work was within 15 days. CONCLUSION: This laparoscopic technique, applied with selective criteria, can be a useful alternative for treating patients with liver hydatidosis because its results are comparable with those for open surgery studies involving similar follow-up time.

Adult↗

Neonatal group B streptococcal infection. Results of 33 months of universal maternal screening and antibioprophylaxis.

OBJECTIVE: To assess the efficacy and pitfalls of a protocol of generalized screening for group B Streptococcus (GBS) and intra-partum treatment of all carriers in a clinical setting. DESIGN: A descriptive study and comparison with an historical group. SETTING: A tertiary perinatal center. POPULATION: All women attending prenatal care in our center and delivered after 37 weeks were eligible. Study period ranged from January 1994 to September 1996. Comparison group consisted in deliveries of years 1992 and 1993. METHODS: Vaginal cultures were performed at 36 weeks on non-selective medium followed by intra-partum treatment of all carrier mothers. Rate of carriage, incidence of neonatal GBS sepsis, influence of risk factors and the reasons for failures were analysed. Comparison was made with an historical group. Statistical analysis was performed using a Chi-square test. RESULTS: There were 5374 term deliveries during the study. 3906 were screened (72.7%) and 559 of them found positive for GBS (14.3%). We observed 46 early-onset GBS diseases (0.86% of term-births). 43.5% of infections occurred in babies born from mothers without risks factors at delivery. Negative GBS cultures at sampling accounted for 43.5% of protocol failures. Comparison of the incidence of early-onset GBS disease with the previous two years showed a significant drop (1.45-0.86%, P<0.05). CONCLUSIONS: Our protocol revealed feasible and effective in reducing the incidence of early-onset GBS disease. Improvements must be studied particularly as to the predictive value of screening cultures.

Amoxicillin↗

[Value of amnioculture for choosing antibiotic treatment for premature rupture of membranes before 34 weeks gestation].

OBJECTIVE: This study attempts to answer the following question: is systematic amniocentesis an efficient tool for adjusting an antibiotic treatment in case of preterm premature rupture of membranes? METHODS: Retrospective study of 76 cases of preterm premature rupture of membranes that occurred between January 1994 and February 1997 in a French teaching hospital. RESULTS: Amniocentesis was impossible for 28 patients (Group I). In this group there was a 46% rate of neonatal sepsis (n=13). Amniocentesis was successful in 48 patients. 24 delivered within 48 hours after amniocentesis (Group IIa). In this group there was a 29% rate of neonatal sepsis (n=7), and amniotic fluid culture was positive in 33% of the cases. 24 delivered beyond 48 hours after amniocentesis (Group IIb). In this group there was a 21% rate of neonatal sepsis (n=5) and amniotic fluid culture was positive in 12.5% of the cases. Group I and IIa had a high risk of neonatal sepsis and could not benefit from amniocentesis culture results. CONCLUSION: Group IIa and IIb cannot be distinguished a priori, therefore systematic amniocentesis can only have a restricted impact on the management of antibiotic therapy. Even in the case of a negative amniotic fluid culture, antibiotic therapy is mandatory. If a systematic amniocentesis policy is used, one hundred amniocentesis have to be performed in order to adapt six antibiotic therapies. In the group with the highest risk of neonatal sepsis (severe oligohydramnios), amniocentesis cannot be performed. A policy of systematic amniocentesis restricted to the cases that are not delivered within the first 48 hours could be evaluated in a prospective randomized trial. Such a policy could help in deciding whether to stop, adapt, or continue the antibiotic therapy, or to induce the delivery in case of an asymptomatic chorioamniotitis.

Amniocentesis↗

[Regionalization of perinatal care and in utero referrals].

Further improvement in perinatal morbidity and mortality figures implies in utero referral so high risk infants, particularly very early maturity infants, can be managed immediately in specialized centers. The success of such referrals depends directly on the coherence of the regional perinatal health care network. It has been demonstrated that the chances of survival and of sequelae-free survival are greater for very premature infants born in a center with a neonatal intensive care unit. The situation in France leaves room for improvement. Only 15% of the infants born before 33 months gestation and with birth weight under 1500 g are born in level III maternity wards equipped with a neonatal intensive care unit. The goal is 80%. We have tried to analyze the reasons behind this situation and propose ways to better organize perinatal health care.

Female↗

[Urinalysis using dipsticks].

Beneath its apparent simplicity, the urinary dipstick is one of the most important advances in the current diagnosis procedure in pediatric nephro-urology. This test represents the best way to approach the most frequent conditions, i.e., urinary tract infection, hematuria and proteinuria. It therefore offers reliable information at a very low financial cost.

Child↗

Are there still obstetric and perinatal benefits for selective embryo reduction of triplet pregnancies?

We present in this study the results of a retrospective analysis comparing a group of ongoing triplet pregnancies and a group of triplet pregnancies reduced to twins. These two groups were managed in the same way between January 1993 and April 1996 in hospital. Mean gestational age at birth was comparable in both groups of patients. Prematurity rate was lower in the reduced pregnancies group (62.5 versus 95.6%, P < 0.05). Severe prematurity (<32 weeks) was not different in the two groups. The percentage of Caesarean section was lower in the reduced group (23.5 versus 70.8%, P < 0.01). No significant difference was observed for perinatal mortality. Newborns of ongoing triplet pregnancies had a higher percentage (67.7 versus 86.8%) of hospitalization in the intensive neonatal care unit and a tendency towards lower birthweight. The differences observed in this study do not seem to represent a decisive benefit for reducing triplet pregnancies. Due to the progress in the management of multiple pregnancies and neonatal intensive care, we think that embryo reduction should no longer be justified by obstetric benefits but rather as a possibility offered to couples who could be confronted with the potential severe psychological, social and economic problems of triple births.

Adult↗

Should we routinely screen for cytomegalovirus antibody during pregnancy?

In order to evaluate the usefulness of cytomegalovirus (CMV) antibody screening during pregnancy, women attending for antenatal care at the Antoine Béclère Hospital (Clamart, France) were prospectively studied during 22 months (1995-1996). Forty-five percent of these women were CMV-seropositive. Twenty suspected or confirmed CMV primary infections were detected. Nine infected infants were born to these women. All infected infants are now between 10 months and 2.5 years old. They all are asymptomatic even those who initially presented abnormal biological parameters or slightly abnormal ultrasound scans during fetal life. Presently, screening for CMV antibody cannot be recommended because it induces economic, psychological and ethical problems. Furthermore, there is no efficient and safe treatment available so far. However, we do think that large studies must be performed to increase our knowledge about the natural history of intrauterine CMV infection. This is also important for an improved assessment of the value of ultrasound examination results as well as the biological parameters measured in fetal blood samples.

Amniotic Fluid↗

[Prevention of prematurity in 842 consecutive twin pregnancies].

OBJECTIVE: To evaluate the effects of a specific management in prevention of prematurity in twin pregnancies. METHOD: The parameters involved in obstetrical follow-up of twin pregnancies were evaluated in a retrospective study of 842 twin pregnancies between 1979-1992. RESULTS: Five-hundred-and-fifteen pregnancies were spontaneous. Two-hundred followed treatment with ovulation induction agents and 127 were due to in vitro fertilization. Early diagnosis of twin pregnancies allowed preventive measures against prematurity. Management of twin pregnancies included rest at home and regular clinical examination of the cervix. Monthly consultations and monthly ultrasounds were performed at hospital. Weekly consultations were made by midwives at home. Hospitalization was not systematic, but was necessary in cases of maternal complications. The diagnosis of twin pregnancy was made before 16 weeks in 82.4% of the cases. The mean gestational age at delivery was 36.2 weeks. The prematurity rate was 45.96%. The mean weight of the neonates was 2,376 +/- 533 g for the first twin and 2,297 +/- 547 g for the second twin. The mean Apgar score at 5 minutes was 9.7 and 9.3, respectively for the first and the second twin. The perinatal mortality was 39.3 per 1,000. The main neonatal complications resulted from prematurity. Twins were hospitalized in the intensive care unit in 20.7 cases. CONCLUSION: The present study supports early diagnosis of multiple pregnancies with systematic ultrasound at 11-13 weeks for each pregnancy, information of the patients, rest at home and regular clinical examination of the cervix.

Bed Rest↗

[Type of birth center and conditions of transfer of neonates under 1500 g or gestational age under 33 weeks].

BACKGROUND: Perinatal care's organization has been widely discussed in France during this last decade. Until now, transfer of high-risk neonates from their birth maternity to a pediatric unit using mobile vehicles led by specialized teams is encouraged in this country. POPULATION AND METHODS: Retrospective analysis of the type of maternities of birth for a population of 717 newborns, weighing less than 1,500 g and/or of gestational age under 33 weeks, extracted from a sample of 84,279 births in 1991. RESULTS: Only 15.6% of studied births took place in a maternity including a special intensive care pediatric unit (international level 3); 58.7% of those newborns where transferred outborn. There was a significant difference between the immediate access of newborns to a level 3 pediatric unit according to the location-of birth: significantly fewer newborns were directly transferred to a level 3 unit when born in a facility that included a level 2 pediatric unit, compared with those born in facilities that included a level 1 or 3 pediatric unit. CONCLUSION: Strong efforts should be made to identify mothers at high risk of giving birth to extremely prematured babies or babies with a very low birthweight so that births could take place in maternities properly equipped for their care. Perinatal care's organization should be built on a hierarchical network of maternities and pediatric services related to the risk of the population. Accreditation of maternities and pediatric services could help moving towards this kind of organization.

Bias↗

First biochemical evidence of differential functional effects following Gamma Knife surgery.

Clinical experience with radiosurgery for epilepsy on lesions located in highly functional areas has suggested the possibility of Gamma-Knife-induced functional effects without deterioration of the underlying cerebral cortex. To investigate these hypothetical functional changes, we have developed a special frame dedicated to small-animal radiosurgical experimental models, allowing purely atlasguided protocols. The left striatum of the first series of rats was targeted with high doses (200 Gy maximum) for validation of this new device. The same target was used with lower doses (50 Gy at the 50% isodose) in the second series to evaluate the biochemical changes and their chronology. The main biochemical changes occurred between 59 and 90 days after Gamma Knife irradiation, with different amplitudes depending on the biochemical parameter observed. Differential effects were first observed between glutamate decarboxylase and choline acetyltransferase, and secondarily between excitatory amino acids (AAs) and non-excitatory AAs, particularly gamma-aminobutyric acid. These preliminary results need to be confirmed and completed by further experimental studies. However, Gamma-Knife-induced differential biochemical effects provide the basis for a promising new concept for functional radiosurgery and particularly the Gamma Knife surgery of epilepsy.

Animals↗

[Experimental radiosurgery in rats using gamma a "gamma knife". Description of a stereotactic device for small laboratory animals].

To allow the experimental use in rats of a Gamma Knife Radiosurgical Unit, a stereotactic device adapted from the conventional Kopf's device was developed. To control the accuracy of the coordinate system based on the De Groot's rat stereotactic atlas, experimental radiosurgical lesions were made on the left striatum. The isodose curve distribution of the 4 mm collimator was calculated with the dose planning software used in Gamma Knife and superimposed on the left striatum target. Doses of 200 Gy were administered to the left striatum in six rats. The results were evaluated 21, 34 and 47 days later. At 34 and 47 days necrotic lesions were exactly as targeted. In a second group of 48 rats receiving a doses of 100 Gy, no lesions were observed after 7, 15, 24, 31, 45 days. However, in all rats sacrificed 59, 72 and 90 days after day radiation, a necrotic lesion was always present and confirmed that at each time the lesions were precisely targeted. This apparatus allows precise and reproducible gamma irradiation lesion in rat brain without expensive and time consuming imaging techniques. This device provides a useful system to observe the experimental effects of radiosurgery on the central nervous system in rats.

Animals↗

Hexose accumulation by enterocytes from the jejunum and rectum of chickens adapted to high and low NaCl intake.

We have studied the effects of adaptation to low NaCl intakes on hexose transport using suspensions of enterocytes isolated from the jejunum and the rectum of the chicken. Animals (12-13 weeks old) were kept for 11 days on either a high-Na+ (HS) or a low Na+ (LS) diet. On day 11, mean serum aldosterone concentration was 46 pg/ml in HS birds and 236 pg/ml in LS birds. Results of transport studies show that: (1) adaptation to a LS diet reduces the cellular 3-oxymethyl-D-glucose cumulative capacity by 40% in the jejunum and is virtually abolished in the rectum; (2) LS adaptation reduces initial alpha-methyl-D-glucoside influx (1 mmol/l) by 22% in the jejunum and by 54% in the rectum; (3) the influx of the membrane potential sensor tetraphenyl-phosphonium (TPP+) in enterocytes strongly suggests that rectal cells of LS birds are significantly depolarized; (4) the presence of 0.1 mmol/l amiloride increases the capacity of the rectal cells of LS birds to establish a sugar gradient across the membrane; (5) incubation of enterocytes with cytochalasin B increases sugar cumulative capacity of the jejunal cells of both HS and LS birds, and has no effect on the rectal cells of LS birds. We conclude that the effects of LS adaptation on sugar transport may involve a reduction in the membrane electrical potential.

Amiloride↗

Effects of ion channel blockers and phorbol ester treatments on [3H]dopamine release and neurotensin facilitation of [3H]dopamine release from rat mesencephalic cells in primary culture.

In this work, we tested the effect of ion channel blockers and of phorbol ester treatments on [3H]dopamine ([3H]DA) release and neurotensin (NT)-induced facilitation of [3H]DA release from cultures of rat fetal mesencephalic cells. The potassium channel blockers tetraethylammonium and 4-aminopyridine increased basal [3H]DA release and decreased K(+)-evoked [3H]DA release, whereas apamin was without effect. K(+)-evoked [3H]DA release was decreased by omega-conotoxin and nifedipine, totally suppressed by cadmium, and unaffected by amiloride. These results show the differential sensitivity of [3H]DA release to blockade of various ion channels and suggest the involvement of N-type, L-type, and non-L-non-N-type, but not T-type, voltage-sensitive calcium channels in K(+)-evoked release. Phorbol 12-myristate 13-acetate increased both spontaneous and K(+)-evoked [3H]DA release, suggesting a modulatory action of protein kinase C on DA release in this system. Unexpectedly, however, the effects of the phorbol ester were not counteracted by the protein kinase C inhibitors H7, staurosporine, or polymyxin B. NT-induced facilitation of K(+)-evoked [3H]DA release was insensitive to most of the ion channel blockers, except cadmium (64% decrease in NT effect), suggesting that the corresponding potassium and calcium channels were not involved in the effect of NT on [3H]DA release in this system. The NT effect was totally suppressed by phorbol ester treatments, indicating a possible desensitization of the corresponding transduction mechanisms after protein kinase C activation.

4-Aminopyridine↗

Potent cocaine analogs inhibit [3H]dopamine uptake in rat mesencephalic cells in primary cultures: pharmacological selectivity of embryonic cocaine sites.

The cellular localization of the cocaine binding sites in primary cultures of embryonic rat mesencephalic cells was previously reported to differ from that observed in adult rat brain. In order to know whether this different localization was associated with a different pharmacological selectivity, we tested the effect of new cocaine analogs on tritiated dopamine ([3H]DA) uptake in primary cultures of rat embryonic mesencephalic cells. In these cultures, [3H]DA was taken up by a nomifensine-sensitive, but desipramine and fluoxetine-insensitive process, reflecting selective uptake by the dopaminergic transporter. 3 beta-(4-Chlorophenyl)tropan-2 beta-carboxylic acid methyl ester (RTI-COC-31) was by far the most potent inhibitor of the [3H]DA uptake, presenting an IC50 of 3.8 nM, while the corresponding analog with an unsubstituted phenyl ring (WIN 35,065-2) was 38 times less potent. The enantiomer of WIN 35,065-2, namely WIN 35,065-3, was 30 times less potent than the former. A similar pattern was found for the relative ability of these compounds to inhibit binding of the radiolabeled cocaine derivative [125I]RTI-55 to membranes prepared from mesencephalic cultures. The order of potencies found for the three cocaine analogs on mesencephalic cultures was similar to that previously obtained in [3H] WIN 35,428 binding experiments and [3H]DA uptake inhibition in adult rat striatum, suggesting that the pharmacological selectivity of cocaine sites functionally related to the DA transporter in cultured embryonic neurons does not differ from that obtained in adult rat brain.

Animals↗

Magnetic resonance imaging of the fetus: a study of 20 cases performed without curarization.

Twenty patients underwent magnetic resonance imaging (MRI) at a mean gestational age of 32 weeks. There were 12 patients with suspected fetal brain abnormality and four with intrauterine growth retardation (IUGR), while the remaining four cases were studied for other reasons. The MRI examinations were performed on a 0.5 Tesla machine, with surface coils. One minute acquisition time T1 sequences were used. All the studies were performed without fetal curarization, and only under maternal sedation using flunitrazepam given per os 1 h before MRI examination. Three examinations were incomplete because of fetal movement artefacts. In the remaining cases, MRI allowed the examination of fetal brain anatomy. In five cases, it helped to differentiate isolated hydrocephalus and corpus callosum agenesis. Sub-ependymal nodules were depicted in a case of fetal tuberous sclerosis. One suspected arachnoid cyst was proved to be an ultrasound artefact. Decreased fetal fat on MR images was correlated with low birth weight in cases of IUGR. Due to its better spatial resolution, ultrasonography was more accurate for the diagnosis of facial and lumbar anomalies. Fetal MRI may be performed without curarization. Surface coils allow the detailed analysis of brain parenchyma, and thus MRI is especially useful in the difficult prenatal diagnosis of fetal brain abnormalities.

Adipose Tissue↗

Biochemical characterization and autoradiographic localization of [125I]endothelin-1 binding sites on trophoblast and blood vessels of human placenta.

The presence of endothelin binding sites in the human placenta raises the question of the precise localization of these receptors on well defined placental constituents. In order to find an answer to this problem various approaches were used. Specific binding sites for [125I] endothelin-1 (ET-1) were identified on human term placenta, not only on membranes of smooth muscles stem villi vessels, but also on trophoblastic plasma membranes prepared from trophoblast in culture. Scatchard analysis of binding data revealed a single class of high affinity binding sites with Kd values of 26 +/- 4 pmol/L for stem villi vessels and 126 +/- 4 pmol/L for trophoblast in culture, with maximum binding capacities of 681 +/- 61 and 224 +/- 53 fmol/mg protein, respectively. The anatomical localization of these binding sites was determined by in vitro autoradiography. Autoradiograms obtained from placental sections incubated with [125I]ET-1 indicate that [125I]ET-1 high affinity binding sites exist on placental stem villi vessels and on the trophoblastic layer of the villi. The latter localization was also found on autoradiograms of trophoblast in culture. The human placental syncytiotrophoblast is a polarized epithelium with the microvillous membrane, facing maternal blood space and the basal plasma membrane, facing fetal circulation. [125I]ET-1 high affinity binding sites are present on both membranes but the number of binding sites is higher on the basal plasma membrane. These findings lead to the suggestion that ET-1 may be involved in the regulation of the feto-placental circulation and may subserve specific trophoblastic functions.

Arteries↗