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Biomedical subjects

H Lambert

Publications and source records attributed to H Lambert.

At least 127 records · Page 7Linked to original sources
PubMed1986

In vitro studies of the golden hamster sperm acrosome reaction: completion on the zona pellucida and induction by homologous soluble zonae pellucidae.

We have studied the occurrence of the golden hamster sperm acrosome reaction (AR) in vitro during interaction with the oocyte investments: the cumulus cell matrix and the zona pellucida. Hamster sperm were capacitated in a defined medium that does not induce the AR. These spermatozoa were allowed to interact with the ovum vestments, the events of which were recorded using high-speed videomicrography. Frame-by-frame analysis revealed that sperm did not complete the AR in the cumulus cell matrix, but did so on the zona pellucida. Furthermore, a higher percentage of sperm completed the AR on the zona pellucida of cumulus-invested than on cumulus-free eggs. We also investigated the effect of solubilized hamster and mouse zonae pellucidae on the hamster sperm AR. Addition of solubilized hamster zonae to capacitated sperm elicited the AR within 15 min. Solubilized mouse zonae were significantly less effective, indicating that the zona-induced AR in hamster sperm may be species specific. These results suggest that the hamster zona pellucida is an inducer of the AR in the intact or soluble form, and that the majority of spermatozoa traverse the cumulus cell matrix without completing the AR in our in vitro system.

Acrosome↗
PubMed1986

Sperm binding activity of the zona pellucida of immature mouse oocytes.

Immature oocytes taken from ovarian follicles are sometimes used in studies of sperm-zona interaction in species for which it is difficult to obtain ovulated eggs. As yet, however, there has been no quantitative comparison of the sperm binding capacities of immature and ovulated oocytes. We report here that in mice there is no significant difference in the numbers of sperm which bind to the zonae pellucidae of immature and ovulated oocytes in vitro. These results support the use of immature oocytes in studies of sperm-zona interaction. We have also analyzed the sources of variability in sperm binding assays, and we make suggestions for the most efficient design of experiments.

Animals↗
PubMed1986

[Acute respiratory distress syndrome in adults in colchicine poisoning].

Two cases of adult respiratory distress syndrome were treated in a series of 26 patients suffering from colchicine overdose. The syndrome appeared between the 24th and 72nd hours. It was characterized by the presence of interstitial as well as alveolar oedema seen on chest roentgenograms. Haemodynamic investigation showed a hyperkinetic state with moderate precapillary pulmonary arterial hypertension. In addition, multivisceral phenomena were observed in all cases. Post-mortem examination revealed interstitial and alveolar pulmonary oedema with haemorrhagic or macrophagic alveolitis often accompanied by hyaline membrane. The physiopathology of ARDS occurring in colchicine poisoning appeared to involve such different factors as infection, the presence of a state of shock and disseminated intravascular coagulopathy. The direct toxic action of colchicine on pneumocyte microtubules and the inhibition of surfactant production were a probable cause. The responsibility of colchicine in leukocyte aggregation remains to be determined.

Adult↗
PubMed1986

[Severe thrombopenia associated with treatment with pentosan polysulfate].

Two cases of severe thrombocytopaenia associated with acute thrombo-embolic manifestations during treatment by pentosan polysulphate, a low molecular weight heparinoid, are reported. Plasma samples from both patients caused in vitro aggregation in the presence of pentosan polysulphate. Interruption of the drug led to the recovery of the platelet count. The hypothesis of an immunoallergic mechanism similar to heparin associated thrombocytopaenia is supported. Furthermore, it seemed likely to be found with all the polysulphated X glycosaminoglycans. During treatment by pentosan polysulphate, platelet count should be monitored to avoid this potentially life-threatening syndrome.

Drug Hypersensitivity↗
PubMed1985

[Fat embolism].

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Embolism, Fat↗
PubMed1985

[Acute choriocapillaris occlusion in pregnancy and puerperium. Toxemias, thrombotic microangiopathies].

Six cases of gravidic toxemia (4) and thrombotic thrombocytopenic purpura (Moschowitz's disease) in puerperium with choriocapillaris occlusion, were examined. At the acute stage, the vision is improved, ophthalmoscopy of the fundus revealed cystlike bullous exudative subretinal with retinal detachment, yellowish spots (of retinal pigment epithelium) and often minimal localized arteriolar narrowing. The evolution included retina application pigmentary disturbances and Elschnig's spots. Fluorescein angiography showed delayed filling of the capillaris and dye leakage in the subretinal space (first hypofluorescence and late hyperfluorescence). There are various stages of ischaemic involvement but in all cases visual symptoms may be due to central obstructive choroidopathy with delayed filling and occlusion. The retinal detachment in toxemia or Moschowitz disease in pregnancy in secondary to microcirculatory choroidal damage (short ciliary vessels essentially) with rupture of blood retinal barrier. Other constatations are made in disseminated intravascular coagulation, periarteritis nodosa, accelerated nephrosclerosis, hemolytic uremic syndrome in puerperium, and these suggested possible relationship between the various conditions.

Choroid↗
PubMed1984

Role of sperm-surface glycoproteins in gamete recognition in two mouse species.

In-vitro fertilization and sperm binding to the zona pellucida within and between Mus musculus (laboratory mouse) and Mus caroli (Asian wild field mouse) were examined. Maximum homologous sperm binding in M. musculus was 12.3 +/- 0.3 spermatozoa bound/egg and in M. caroli, 9.2 +/- 0.2. In heterologous crosses, sperm-zona binding was significantly reduced (M. musculus eggs with M. caroli spermatozoa, 1.9 +/- 0.14; M. caroli eggs with M. musculus spermatozoa, 5.5 +/- 0.2). Homologous sperm-zona interaction was inhibited by different sugars in the two mouse species (M. caroli by alpha-methyl mannose, M. musculus by sialic acid). The data suggest that gamete recognition is highly species specific and that hapten sugars play a significant role in sperm-zona binding.

Animals↗
PubMed1984

[Acute edema of the lung in eclampsia].

In 6 cases of eclampsia in the course of pre and post-partum, we could observe neurological disorders associated with acute pulmonary oedema with acute respiratory distress occurring 5 to 72 hours after the first convulsive crisis. Hemodynamic check-up provided various results: 3 cases corresponded to A.P.O resulting from a lesion, with normal capillary pressure. In 3 other cases, there was hemodynamic oedema (overloading with high flow and hypervolemia in one case, myocardial incompetence with hypovolemia in an other case revealed by test filling in a third case). There were clinical signs of left ventricular failure in 4 case. Post-mortem investigations (5 cases) revealed unimportant ultrastructural alterations of myocardium only in 2 cases. Pulmonary histopathological investigations (5 cases) were the investigations carried out in case of oedema resulting from lesions with interstitial and alveolar oedema, hyaline membranes, alteration of pneumocytes, and intra-capillary thrombi. Mendelson's syndrome which was always discussed could be eliminated. The syndrome of respiratory distress was certainly connected with more or less generalized microcirculatory disorders (microembolism with hyperpermeability) connected with hemostasis disorders and cerebral manifestations.

Acute Disease↗
PubMed1983

[Prevention of pulmonary embolism by the Kimray-Greenfield filter. 22 cases].

At present, the Kimray-Greenfield filter appears to be the best intraluminal method for preventing thromboembolism, as it is simple, effective and innocuous. The authors report their experience in the first 22 cases. They were surprised by the frequent problems encountered in installing the filter, especially by the femoral route. Two accidents occurred during the procedure: a filter introduced through the jugular vein migrated as soon as it was released, and a patient developed sudden and irreversible coma during passage of the guiding instrument behind the clavicle. Cavographies performed in 10 patients after one month or more disclosed two thromboses of the inferior vena cava and a tipped-over filter. Eight filters remained permeable. No recurrence of pulmonary embolism was observed.

Aged↗
PubMed1983

Analysis of the passive mechanical properties of rat carotid arteries.

The passive mechanical properties of rat carotid arteries were studied in vitro. Using a tensile testing machine and a piston pump, intact segments of carotid arteries were subjected to large deformations both in the longitudinal and circumferential directions. Internal pressure, external diameter, length and longitudinal force were measured during the experiment and compared with the in vivo dimensions of the segments prior to excision. The anisotropic mechanical properties of the vessel wall material were analyzed using incremental elastic moduli and incremental Poisson's ratios. The results suggest that there is a characteristic deformation pattern common to all vessels investigated which is highly correlated with the conditions of loading that occur in vivo. That is, under average physiological deformation of the vessel, the longitudinal force is nearly independent of internal pressure. In this range of loading the circumferential incremental elastic modulus is nearly independent of longitudinal strain. However, the longitudinal and radial incremental elastic moduli vary significantly with deformation in this direction. The values of the moduli in all three directions increase with raising internal pressure. The weak coupling between circumferential and longitudinal direction in the wall material of carotid arteries is shown by the small value of the corresponding incremental Poisson's ratios.

Animals↗
PubMed1983

Differences in the DNA of the inactive X chromosomes of fetal and extraembryonic tissues of mice.

We have examined the role of DNA modification in X chromosome inactivation of fetal tissues of the mouse using DNA-mediated gene transfer for the gene hypoxanthine phosphoribosyltransferase (HPRT). Two types of tissues have been examined with respect to randomness of inactivation in 14-day mouse conceptuses: 1) fetal tissue, which undergoes random inactivation of either the maternal or paternal X; and 2) yolk sac endoderm tissue, an extraembryonic membrane, which normally undergoes nonrandom inactivation of the paternal X. Exploiting an electrophoretic variant of HPRT as a means to mark the active and inactive HPRT alleles we provide evidence that: 1) inactive X DNA of the fetus at 14 days behaves like that of both adult tissue and cell lines in that the inactive X DNA is not efficient in gene transfer; and 2) in contrast, inactive X DNA from yolk sac endoderm is functional in gene transfer. Thus, despite the similarity in single active X chromosome expression in yolk sac endoderm and somatic tissues, there appears to be a difference at the level of DNA modification between these two tissues.

Animals↗
PubMed1983

[Morphologic aspects of intravascular disseminated coagulation. Apropos of 100 cases].

The authors report a morphological study of one hundred cases of disseminated intravascular coagulation (D.I.C.) of various origins. In each case laboratory findings demonstrated an authentic consumption coagulopathy. In all cases organ biopsies were performed either in vitro (rarely), or mainly immediately after death or at autopsy. Optic microscopy was performed for all of them (3 stains were chosen: hemalum eosin saffron, Mallory's phosphotungstic acid hematoxylin stain, P.A.S.). For a smaller number of cases ultrastructural microscopy and immunofluorescence were performed. As far as microscopic findings are concerned, the authors insist particularly upon intravascular microthrombi (fibrinous type and hyalin type). Haemorrhages and particularly necrosis, because of multiple origin, are not detailed. The repartition of these microthrombi is particularly detailed (in connection with the different organs, etiologies, clinical and/or biological findings, treatments). A review of literature is reported.

Adolescent↗