Localization and synthesis of hyaluronic acid in the cumulus cells and mural granulosa cells of the preovulatory follicle.

Mural and cumulus granulosa cells synthesize hyaluronic acid (HA) and expand in vitro in response to follicle-stimulating hormone and a soluble factor(s) produced by fully grown oocytes. In the present study we examined HA synthesis and extracellular matrix organization by the two cell populations in vivo during the preovulatory period. After injection of human chorionic gonadotropin into pregnant mares' serum gonadotropin-primed animals, a progressive increase in HA synthesis was observed by the cumulus cell-oocyte complex (COC), and by the mural granulosa cells adjacent to the antrum (antral granulosa cells). The outermost layers of mural granulosa cells (peripheral granulosa cells) did not synthesize HA. Net HA synthesis was approximately 4 pg/cell for COCs isolated after full expansion induced either in vivo or in vitro, whereas the total HA content and cell number in the ovulated COC (approximately 11 ng HA and approximately 3000 cells per COC) were about threefold higher than for COCs expanded in vitro (approximately 4 ng HA and approximately 1000 cells per COC). The increased cell content of ovulated COCs appears to be primarily the result of inclusion of proximal mural granulosa cells which synthesize HA in response to the oocyte factor(s) and become incorporated in the expanded COC extracellular matrix mass. Media conditioned by oocytes enclosed in the cumulus cell mass (intact COCs) contained only 10-20% of the HA-stimulatory activity of media conditioned by an equal number of isolated oocytes when tested on mural granulosa cell cultures. Further, HA-stimulatory activity of media conditioned by isolated oocytes was dramatically reduced (approximately 70%) by preincubation for 5 hr with cumulus cells compared to preincubation in the absence of cells. The results suggest that differences in HA synthesis between subregions of membrana granulosa depend on a diffusion gradient of the oocyte factor(s).     

Effect of excess boron on summer and winter squash

The boron tolerance of two summer squash cultivars (Cucurbita pepo L. Aristocrat Zucchini and Peter Pan Scallop) and one winter squash cultivar (Cucurbita moschata Poir. Butter boy) was determined in large, outdoor sand cultures. Boron treatments were imposed by irrigation with culture solutions that contained 1.0, 3.0, 6.0, 9.0, 12.0, or 15.0 mg B L^-1. Relative fruit yields of Zucchini, Scallop, and Butter boy were reduced 5.2%, 9.8%, and 4.3% with each unit (mg L^-1) increase in soil solution B (B_sw)>2.7, 4.9, and 1.0 mg B L^-1, respectively. Reduced yields of all cultivars were attributed to a reduction in fruit number and not fruit size. Boron concentrations in leaves and fruit were directly correlated to B_sw.     

Study by in situ hybridization of the prevalence of herpes virus as cofactors of the tumoral development of papillomatous lesions of the anogenital region in seropositive and seronegative men against HIV]

Infection with specific types of HPV has emerged as necessary but not sufficient factor in the neoplastic transformation of anogenital condylomas. Some viruses (HIV, Herpes viridae: HSV, CMV, EBV) might act as cofactors in the neoplastic changes and cancer. To study the prevalence of these viral pathogens in anogenital lesions, biopsies were obtained from HIV seropositive or seronegative men and tested using in situ hybridization technique. Infection by "high risk" HPV, HSV and CMV are facilitated in patients immunocompromised by HIV. Presence of CMV is more frequent in high risk HPV-induced lesions than in low risk HPV lesions.     

Genetic variability in the Arabian oryx (Oryx leucoryx)

An electrophoretic survey of blood markers of the Arabian oryx (Oryx leucoryx) was undertaken in order to ascertain the genetic variability in a sample of 85 individuals, mainly from Saudi Arabian (Taíf) and Jordanian herds. Three out of 18 loci were found to be polymorphic (P = 16.7%) and the mean heterozygosity (H = 0.052) appears to be relatively high with respect to the severe demographic bottlenecks expressed by the species since the 1960s. No genetic differentiation was found between Arabian and Jordanian samples considered. Consequences of these findings for the management of the Taíf herd and for such procedures as pedigree determination are discussed, and an example of this latter application is given for a case of doubtful parentage.     

Growth of sebaceous cells in monolayer culture

Summary Rat preputial cells were grown in an epithelial cell primary monolayer culture system identical to that used for culturing epidermal cells, which were studied for comparison. Despite similar appearance when observed by phase contrast microscopy, other features identified the preputial cells as a unique epithelial cell population. Preputial cells grew as a relatively small number of large colonies, formed domes before confluence, and expressed a specific acinar keratin, K4, which had previously been found in human sebaceous glands. In addition, preputial cells formed fewer cornified envelopes than epidermal cells, too few to discern the reduction of envelope formation by retinoic acid treatment in vitro which was found in epidermal cells. Rat preputial cells in monolayer culture, therefore, are a promising model for studying the effects of hormones on sebaceous cell growth and differentiation.     

Divergence of protamine gene sequences in fish

Complementary DNA to trout protamine mRNA was hybridized to excess genomic DNA from trout, salmon and yellow perch. Although there was extensive hybridization of the cDNA to trout DNA, no cross-reaction with yellow perch DNA was observed and the hybridization to salmon DNA was noticeably less than in the homologous reaction. To confirm these results, yellow perch protamine mRNA was purified and compared directly to trout protamine mRNA. Yellow perch protamine mRNA was shorter than trout protamine mRNA, when measured by agarose gel electrophoresis in the presence of methyl mercury hydroxide. The two mRNAs did not cross-react in cDNA/RNA hybridizations, although the homologous reactions went to 90% of completion. This lack of sequence homology was confirmed when the oligopyrimidine tracts from the cDNAs were compared. No sequences longer than tetranucleotides were common to both species. Trout protamine cDNA contained oligopyrimidines of composition C₇T₄, C₄T₂, C₃T₂, C₂T₄, C₂T₃, C₁T₅ and C₁T whereas yellow perch protamine cDNA contained C₆T₃ and C₄T₃.     

Identification on I-Ak molecules of a functional site recognized by proliferating T-lymphocytes

The inhibitory capacity of 17 monoclonal antibodies (m.Ab.) specific for the products of the I-A ^k subregion was evaluated in proliferative responses of B10.BR T-lymphocytes to GAT, Keyhole limpet hemocyanin, and ovalbumin. Considered in isolation, each m.Ab. mediated inhibitory effects of comparable magnitude on these three different proliferative responses. On the other hand, clear differences were observed when the magnitude of the inhibitory effects was compared from one m.Ab. to another. The m.Ab. were consequently classified as strong or moderate-to-weak inhibitors of T-cell proliferative responses. Evidence was simultaneously gained indicating the following: (a) the determinants recognized by different m.Ab. were expressed on the same molecules; (b) the differences in affinity of the m.Ab. for I-A^k positive cells did not explain their differences in inhibitory capacities; (c) conversely, the inhibitory capacity of each m.Ab. followed its ability to inhibit the cell surface fixation of Ia.17-specific 10-2.16 m.Ab.; (d) the strong inhibitory capacity of some m.Ab. was not related to a special ability to modulate cell surface Ia molecules. These results suggest that antigen recognition by T lymphocytes is preferentially restricted by a functional site of the I-A^k molecules related to the Ia.17 and Ia.1 specificities.Abbreviations EDTA Ethylenediamine-tetraacetic acid disodium salt - EHAA Eagle's Hanks' amino acids medium - FCS fetal calf serum - in polypeptide G is glutamate, A, alanine, T, tyrosine - HEPES N-2-hydroxy-piperazine-N-2-ethane sulfonic acid - kd dissociation rate constant - KLH Keyhole limpet hemocyanin - LPS lipopolysaccharide - m.Ab. monoclonal antibodies - NP-40 nonidet P-40 - PBS phosphate buffered saline - PBS-BSA PBS supplemented with 1% bovine serum albumin - PBS-BSA-NP-40 PBS-BSA supplemented with 0.5% NP-40 - RT room temperature - SEM standard error of the mean - s.c. spleen cells     

Adhesive specificity of developing cerebellar cells on lectin substrata

Ten lectins, each with a different carbohydrate-binding specificity, have been coupled to tissue culture substrata with carbodiimide [1-cyclohexyl-3-(2-morpholinoethyl)-carbodiimide-metho-p-toluene sulfonate] and assayed for their efficacy as substrates for the carbohydrate-specific adhesion of cells dissociated from mouse cerebellum at embryonic Day 13 and postnatal Days 0 and 7. On surfaces treated with concanavalin A, succinyl-concanavalin A, Lens culinaris agglutinin, and wheat germ agglutinin, both embryonic and early postnatal cerebellar cells formed a monolayer. On surfaces coupled with Ricinus communis_I agglutinin (120,000 daltons) both embryonic and postnatal cells formed cellular aggregates with extensive fiber outgrowth. On surfaces treated with peanut agglutinin, Dolichos bifloris agglutinin, Wistaria floribunda agglutinin, soybean agglutinin, or Ulex europaeus_I agglutinin, embryonic cerebellar cells formed cellular aggregates with a cell viability of 25–35% and little or no fiber outgrowth. Postnatal cerebellar cells, in contrast, formed cellular aggregates with a cell viability of 60–70% and extensive fiber outgrowth. On surfaces treated with Ulex europaeus_I agglutinin, cells from postnatal Day 7 formed limited areas of monolayer in addition to cellular aggregates. After 12 hr in vitro the specific attachment of cerebellar cells to lectin-derivatized substrata was inhibited 60–80% by the inclusion of free hapten carbohydrate (50–100 mM) in the growth medium. The addition of soluble concanavalin A or Ricinus communis_I agglutinin (100 μg/ml) was toxic. These studies suggest the presence of glycoconjugate-binding sites for concanavalin A, Lens culinaris agglutinin, and wheat germ agglutinin which promote cerebellar cellular adhesion.     

Les Radiolaires d'âge jurassique supérieurà crétacé supérieur dans les Radiolarites du Pinde-Olonos (Presqu'île de Koroni; Péloponnèse méridional,Grèce)

Radiolarians of several radiolarites sections of the Pindos-Olonos zone, southern Peloponnesus, lead to propose direct datations of mesozoic sediments. The acuity of such datations allow to distinguish two periods for depositionof radiolarites s.s. in the tethyan region. The first period would be Upper Jurassic and general in tethyan realm, radiolarites depositing under various latitudes (0–35°N). This would be the result of a strong ocean surface current. The second period would be Upper Cretaceous (Vraconian—Coniacian) and be geographically much more restricted (0–15°N). This could result from a weaker current. The absence of radiolaritic sedimentation is possibly the result of the destruction or insulation of the accurate basins during the obduction of ophiolites on the apulo-african realm. The inventory of Late Cretaceous radiolarian fauna, rarely done on alpine series so far, shows similar result to those obtained in Central American and California.     

Cockroach collagen: isolation, biochemical and biophysical characterization

Collagen fibrils from the mesenteric connective sheath of the adult cockroach Periplaneta americana were extracted by enzymatic digestion with pepsin and were purified. Chromatographic studies and sodium dodecylsulfate electrophoresis revealed the presence of a single chain. It was demonstrated that the structure of this collagen could be represented by the formula (alpha)3. The amino acid composition is typical of collagens (one-third glycine, and a high imino acid content) and similar to that of type II. The carbohydrate content was high (8.8%), and the cyanogen bromide pattern was different from that of known collagens. The chains were linked by the stable intermolecular bond dihydroxylysinonorleucine. The banding patterns of the segment-long-spacing crystallites and of the reconstituted fibrils were similar to type I collagen. The molecular weight (Mr 280,000) and length (285 nm) were typical, but the denaturation temperature was high (38.5 degrees C). It was concluded that cockroach mesenteric collagen showed the characteristic features of invertebrate mesodermal collagens, except that of the thermal stability of the triple-helical structure.