Sperm plasma membrane damage prior to intracytoplasmic sperm injection: a necessary condition for sperm nucleus decondensation

In the present study we investigated the relevance of spermimmobilization prior to intracytoplasmic sperm injection (ICSI)in the fertilization process. Using supravital staining of thespermatozoa with eosin and studying sperm decondensation with2 mM dithiothreitol (DTT) in conditions imitating sperm handlingduring ICSI, we demonstrated that immobilization of the spermatozoonby squeezing its tail between the glass pipette and the bottomof the dish damages the sperm plasma membrane. Polyvinylpyrrolidone(PVP), which is usually present in the drop with the spermatozoonto facilitate its handling, was found to impede the access ofboth eosin and DTT to the sperm nucleus. We conclude that (i)sperm immobilization prior to ICSI damages the sperm plasmamembrane, that (ii) this damage is sufficient for thiol-reducingagents to gain access to the sperm nucleus, and finally that(iii) PVP possibly interferes with sperm nucleus decondensation.     

慢性肾衰患者外周血IL-18水平及血液透析对其的影响

为探讨慢性肾衰竭 (CRF )患者外周血IL 18表达量的变化以及血液透析 (HD )对其表达的影响 ,选取 10名健康志愿者及 2 9例CRF患者 ,应用ELISA测定血浆IL 18水平 ,同时采用半定量逆转录多聚酶链反应 (RT PCR )技术 ,检测PBMC中IL 18mRNA表达量。结果是未行HD的CRF患者血浆IL 18水平及PBMCIL 18mRNA表达量较正常对照组增高 ,差异有显著统计学意义 (P <0 0 1) ,单次HD对CRF患者血浆IL 18水平及基因表达无明显影响 (P >0 0 5 ) ,但长期维持HD则可使CRF患者外周血IL 18水平及基因表达增高 (P <0 0 5 )。提示外周血IL 18的高表达可能参与CRF的发病过程及HD相关并发症的发生发展     

Burkitt's lymphoma: new insights into molecular pathogenesis

The World Health Organisation classification reports three subcategories of Burkitt's lymphoma (BL)--endemic, non-endemic, and immunodeficiency associated--proposed to reflect the major clinical and genetic subtypes of this disease. These different types of BL have been reviewed and studied by immunohistochemistry and molecular methods. The results point out the heterogeneity of BL and suggest that AIDS related BL may have a different pathogenesis from that of classic BL.     

Anti-Müllerian hormone concentrations in maternal serum during pregnancy

BACKGROUND: In females, anti-Müllerian hormone (AMH) is expressed only by the ovary. AMH is secreted by the granulosa cells of ovarian follicles and appears to regulate early follicle development. AMH is detected in serum from women of reproductive age and its levels vary slightly with the menstrual cycle, reaching the peak value in the late follicular phase. This study investigated serum AMH levels throughout gestation and after delivery in healthy pregnant women. METHODS: This cross-sectional study recruited pregnant women and healthy non-pregnant women, 84 in total. AMH, FSH and E2 were measured in the follicular phase, in the three trimesters of pregnancy and in early puerperium. RESULTS: Estradiol and FSH levels followed the expected patterns during gestation. During the follicular phase of the menstrual cycle AMH levels were 1.9 +/- 0.5 ng/ml. In the three trimesters of pregnancy and in early puerperium AMH levels were: 2.1 +/- 0.56, 2.4 +/- 0.64, 1.95 +/- 0.6 and 2.05 +/- 0.55 ng/ml respectively. No significant modifications were found in AMH levels during pregnancy and in the early puerperium. CONCLUSIONS: This study has obtained information on AMH and on the possible relationship with FSH. We hypothesize that the profile of the new marker of ovarian activity AMH may indicate that initial non-cyclic ovarian follicular activity during pregnancy is not abolished. Moreover FSH, does not seem to play a direct role on AMH synthesis and secretion.     

T cell receptor γδ repertoire is skewed in cerebrospinal fluid of multiple sclerosis patients: molecular and functional analyses of antigen-reactive γδ clones

To study the relevance of γδ T cells in multiple sclerosis (MS) we analyzed the T cell receptor (TCR) γδ repertoire and the antigen reactivity of γδ clones isolated from cerebrospinal fluid (CSF). In T cell cultures derived from CSF we found an increased percentage of Vδ1⁺ cells as compared to peripheral blood of the same donors. Phenotypic analysis of cells from MS CSF with Vγ- and Vγ-specific monoclonal antibodies (mAb) showed that the Vγ1 chain is most frequently associated with γ chains belonging to the VγI family. Sequence analysis of TCR genes revealed heterogeneity of junctional regions in both δ and γ genes indicating polyclonal expansion. γδ clones were established and some recognized glioblastoma, astrocytoma or monocytic cell lines. Stimulation with these targets induced serine esterase release and lymphokine expression characteristic of the T_H0-like phenotype. Remarkably, these tumor-reactive γδ cells were not detected in the peripheral blood using PCR oligotyping, but were found in other CSF lines independently established from the same MS patient. Altogether, these results demonstrate that in the CSF there is a skewed TCR γδ repertoire and suggest that γδ cells reacting against brain-derived antigens might have been locally expanded.     

Sensitivity to tomato and peanut allergens in children monosensitized to grass pollen

Possible associations between allergy to grass pollen and positive skin tests to food allergens were studied in 102 children monosensitized (as to inhalant allergens) to grass pollen, and in 117 children monosensitized (as to inhalant allergens) to Dermatophagoides. Thirty-two foods were tested by an epicutaneous method. Positive skin tests to food allergens were more frequent in children with allergy to grass pollen (59.8%) than in children with allergy to Dermatophagoides (9.4%). A considerably high frequency of positive reactions to tomato (39.2%), peanut (22,5%), green pea (13.7%), and wheat (11.7%) was observed in children with allergy to grass pollen. Positive skin tests to peanut closely correlated with positive RAST results and nasal provocation tests, whereas in children with skin test positivity to tomato a close correlation with nasal provocation tests but a 45% correlation with a positive RAST result were observed. RAST inhibition experiments were carried out, and the results may suggest the presence of cross-reacting IgE to grass pollen, tomato, and peanut antigens. Clinical implications of these findings are discussed in the light of histories of food hypersensitivity, urticaria-angioedema, and atopic dermatitis in children with allergy to grass pollen.     

Wall effects in sucrose density gradient centrifugation of viruses

Summary The depletion of sedimenting particles to be expected from wall effects in the course of sucrose gradient centrifugation, was computed for various types of swing-out rotors on the assumption that particles hitting the tube wall are lost from the gradient.This assumption was roughly verified for heat-denatured, but not for native poliovirus. Tween 20 reduced the depletion, and prevented tight sticking of heat-denatured virus particles to tube walls.     

Neocortical and hippocampal EEG in normal and lateral hypothalamic-damaged rats

Cortical and hippocampal EEG were correlated with behavior in rats before and after bilateral hypothalamic (LH) damage. In Stage 1 of recovery (aphagia and adipsia), the neocortex showed continuous large amplitude slow activity. It did not desynchronize during spontaneous acts such as grooming as well as during tail pinch-induced struggling or orienting, even though a slow form of hippocampal theta accompanied these acts. However, during Stage 2 (anorexia), the neocortical EEG did desynchronize when such theta appeared. Therefore, as behavioral recovery progresses after LH damage, there appears to be a concomitant recovery of cortical participation in such behavior. Early in recovery, LH rats, unlike normals, showed slow (3–4.5 Hz) atropine-sensitive hippocampal theta during automatisms such as grooming as well as during immobility. Thus, LH damage, while temporarily abolishing fast. noncholinergic theta, appears to release slow cholinergic theta. Later in recovery, faster atropine-resistant (noncholinergic) theta becomes functional again.