Cyclooxygenase-2 is expressed by cumulus cells during oocyte maturation in cattle.

Prostaglandins could be involved in various aspects of final differentiation of ovarian follicles. Prostaglandins are generated by the cyclooxygenase (cox) pathway. Until now, the expression pattern of isoforms cox-1 and cox-2 of cyclooxygenase in bovine cumulus-oocyte complexes (COCs) was unknown. Using immunodetection procedure, we demonstrated in the present study that cox-2 was expressed by cumulus cells during in vivo and in vitro maturation. Time course induction of cox-2 expression was investigated during in vitro maturation using Western blot analysis. Specific signal of cox-2 was markedly evidenced from 6 hr of culture and increased to reach a maximal level at 24 hr of culture. In vitro, cox-2 expression in COCs was associated with increased concentrations of PGE(2) and PGF(2alpha) in the maturation medium. In addition, the effects of culture conditions on cox-2 expression was considered using RT-PCR and Western-blot analysis. We demonstrated that the addition of 10 ng/ml of EGF to TCM199 clearly increased the expression level of cox-2 mRNA and protein. Higher levels of in vitro cox-2 expression was associated with greater rates of cumulus expansion and oocytes at metaphase II at 24 hr of culture. In conclusion, our present results suggest that cox-2 expression in cumulus cells may be involved in differentiation of COCs that occurs during oocyte maturation.     

Varicella-zoster virus in actively spreading segmental vitiligo skin: Pathological,immunochemical, and ultrastructural findings (a first and preliminary study)

Segmental vitiligo (SV) is a unilateral subtype of vitiligo which is clinically characterized by a cutaneous depigmentation and histologically by a melanocyte loss from the epidermis and hair follicle reservoirs. To date, its pathogenesis remains a mystery. In many cases, this skin depigmentation shares several clinical features and dysfunctions with herpes zoster (HZ). So, for the first time, we examined whether any nucleus and cell fusion associated with a positive immunolabelling of varicella-zoster virus (VZV) and VZV mature virions could be found in SV skin samples as in herpes zoster (HZ). A total of 40 SV samples were used for histological and immunochemical studies. Control samples were obtained from three HZ, and 10 generalized vitiligo lesions. For ultrastructural study, three recent SV and one HZ as controls were recruited. Here, we report that nuclear fusion in epidermal cells were statistically associated with recent SV (p < .001), whereas syncytia formation was associated with long-lasting SV (p = .001). A positive detection of VZV antigen was statistically associated in the epidermis with recent SV and in the dermis with long-lasting SV (p = .001). Finally, the discovery of mature virions in 3/3 recent SV samples provides additional arguments for our viral hypothesis.     

Influence of physical conditions on the oxidation of hemoglobin during freeze-drying

The potential influence of some physical conditions--dialysis, crystallization, concentration, pH, and temperature--on the amount of methemoglobin obtained after freeze-drying of hemoglobin has been studied. Among these parameters, pH and crystallization influence the oxidation. In acid medium (pH 5), the oxygen saturation is better than that obtained for pH 8. Crystalline hemoglobin leads to a methemoglobin rate significantly lower (29% versus 49%) than untreated hemoglobin. Methemoglobin is continuously formed during desiccation even at the lowest temperature. Although it has been possible to lessen the denaturation of hemoglobin by the choice of a definite preliminary treatment of the samples, we were not able to reduce methemoglobin to low and physiological values. However, the results obtained with crystalline hemoglobin make it possible to propose mechanisms for the oxidation of the hemoprotein.     

Etude cytochimique des hémocytes des crustacés décapodes brachyoures

Histochemistry and Cell Biology - Les hémocytes de deux espèces de crabes, Eriocheir sinensis et Carcinus maenas, ont été soumis à différentes réactions...     

Evolution de la radioactivité des cellules neurosécrétrices de la pars intercerebralis chez Locusta migratoria migratorioides (Insecte Orthoptère) après injection de cystéine S35

Résumé Après injection de cystéine S³⁵, les cellules A, B, C et les neurones banaux de la pars intercerebralis chez Locusta (femelles immatures et mûres) sont radioactifs. Le taux d' incorporation de la cystéine S³⁵ dans les cellules B est identique chez toutes les femelles et il est légèrement supérieur à celui des neurones banaux. Ces résultats confirment l'inactivité sécrétoire protéique des cellules B. Les cellules C incorporent 3 à 5 fois plus de cystéine S³⁵ que les neurones banaux. Elles synthétisent donc une ou plusieurs protéines contenant de la cystéine ce qui réaffirme leur activité neurosécrétrice chez Locusta. Les cellules A possèdent le taux d'incorporation de cystéine S³⁵ le plus élevé: 5 à 8 fois celui des neurones banaux.Chez toutes les femelles, les cellules A synthétisent plus de neurosécrétion et en éliminent proportionellement plus que les cellules C. La neurosécrétion A est élaborée sous sa forme figurée plus rapidement (30 min) que la neurosécrétion C (60 min). Le renouvellement de la neurosécrétion A est donc quantitativement plus important et plus rapide que celui de la neurosécrétion C. Chez les femelles immatures, les cellules A et C synthétisent plus de matériel et en éliminent proportionnellement plus que chez les femelles mûres. Le temps nécessaire à l'élaboration et à la vidange des grains de neurosécrétion A est identique chez toutes les femelles. Il en est de même pour le matériel C. Le renouvellement des neurosécrétions A et C est donc plus important chez les femelles immatures que chez les femelles mûres mais il n'est pas plus rapide. L'accumulation du matériel fuchsinophile dans les cellules A et C lors de la maturation ovarienne correspond à une réduction de leur fonction neurosécrétrice: elle résulte d'une diminution de l'activité d'élimination des cellules neurosécrétrices A et C supérieure à l'affaiblissement de leur activité de synthèse.

---

Evolution of the radioactivity of the neurosecretory cells of pars intercerebralis in Locusta migratoria migratorioides (insect orthoptera) after injection of ³⁵S-cysteineAn autoradiographic study by optical and electronic microscopy

Summary After injection of ³⁵S-cysteine, the A, B, C cells and the ordinary neurones of pars intercerebralis in Locusta — immature and mature females — are radioactive. The rate of incorporation of ³⁵S-cysteine into the B cells is the same for all the females, and it is slightly higher than the rate of incorporation of ³⁵S-cysteine into the ordinary neurones. These results demonstrate the proteinic secretory inactivity of the B cells. The C cells incorporate 3 to 5 times more ³⁵S-cysteine than ordinary neurones. Thus, the C cells synthesize one protein or several proteins with cysteine; this observation confirms their neurosecretory activity in Locusta. The A cells have the highest rate of incorporation of ³⁵S-cysteine: 5 to 8 times the one of ordinary neurones.In all the females, the A cells produce and release proportionally more neurosecretion than the C cells. The production of granules is faster in A cells (30 min) than in C cells (60 min). The turnover of the A neurosecretion is consequently higher and quicker than the C neurosecretion. In immature females, the A and C cells synthesize and release proportionally more material than in mature females. The time necessary for production and release of the A neurosecretion is the same for all the females. It is so for the C material. The turnover of the A and C neurosecretions is thus more important in immature females than in mature females but it is not more rapid. The accumulation of stainable neurosecretory material in A and C cells at the time of ovarian maturation is associated with a reduction of their neurosecretory activity: it is due to a decrease of the rate of release of the A and C cells being more important than their rate of production.

     

In vivo assessment of tumor-induced nonspecific suppression of contact sensitivity

Summary Normal BALB/c mice were assessed for 2,4-dinitrofluorobenzene (DNFB)-induced contact sensitivity following adoptive transfer of macrophages (Mo). T cells, or their derived products, from normal or tumor-bearing hosts (TBH). Contact sensitivity (CS) was measured by a quantitative radioisotopic ear assay, a total in vivo system based on localization of IP-injected iodinated human serum albumin ([¹²⁵I]HSA) in the DNFB-challenged ear. Adoptive transfer of low or high doses of TBH T cells or their derived supernatants into normal recipients suppresed their responsiveness, while Mo supernatants enhanced it. Moreover, in all cases adoptive transfer of TBH cells or supernatants resulted in a lower CS response than did their normal counterparts. These results further corroborate our previous in vitro data indicating that T cells, or Mo and T cell soluble products, possess immunoregulatory capabilities in vivo.Abbreviations DNFB 2,4-dinitrofluorobenzene - TBH tumor-bearing host - Mo macrophages - ¹²⁵I-HSA iodinated-human serum albumin - CMI cell-mediated immunity - CS contact sensitivity; Ig, immunoglobulin - C complement     

Chromosomal Localization of Human RNA Polymerase II Subunit Genes

The eukaryotic DNA-dependent RNA polymerase II (or B) is composed of 10 to 14 polypeptides ranging from 220 to 10 kDa. To gain further insight into the molecular structure and function of these subunits, we have undertaken the molecular cloning of nucleotide sequences corresponding to the human enzyme. The cDNAs of five subunits (hRPB220, hRPB140, hRPB33, hRPB25, and hRPB14.5) have been isolated. Using in situ hybridization, we show that the genes of these subunits have distinct chromosomal locations (17p13, 4q12, 16q13-q21, 19p13.3, and 19q12, respectively). Thus, if assembly of active polymerase molecules requires coordinated expression from these independent genes, mechanisms that ensure tight coregulation of the corresponding promoters must exist.     

Isoelectrofocusing of erythrocyte galactose 1 phospho uridyl transferase in a family with both galactosemia and duarte variants

Summary A family with the presence of the genes for both galactosemia and the Duarte variant is described. Galactose 1 phospho uridyl transferase has been studied not only by electrophoresis on starch gel, but also by isoelectrofocusing on thin-layer acrylamide.Normal and variant transferases were resolved into three bands, the isoelectric point of which was between 5.40 and 5.10 for the normal subjects, and between 5.25 and 4.95 for subjects with the Duarte variant.