Developmental changes in the intraplacental distribution of placental lactogen and alkaline phosphatase in the rat

The junctional and labyrinth regions of the rat chorioallantoic placenta during the second half of gestation showed different patterns of development with regard to DNA, protein, placental lactogen and alkaline phosphatase content. DNA and protein measurements indicated that growth of the labyrinth region was more rapid and persisted for longer during gestation than did growth in the junctional zone. At midpregnancy the junctional zone was the main source of placental lactogen whereas by late pregnancy both regions contributed considerable amounts. On Day 20 of gestation the labyrinth region contained significantly more placental lactogen than did the junctional zone. Alkaline phosphatase activity was predominant in the labyrinth zone throughout the second half of gestation. The results indicate that the chorioallantoic placenta is composed of two functionally distinct regions.     

Plasma cell granuloma of the tongue. Report of a case

A case of plasma cell granuloma of the tongue in an otherwise symptomless 48-year-old caucasian female is reported. The polyclonal nature of the plasmocytes was revealed by immunostaining of kappa and lambda light chains. Electron microscopic observations showed typical mature plasmocytes. A parasitic etiology of this type of lesion is suggested.     

Fatty acid oxidation in bone tissue and bone cells in culture. Characterization and hormonal influences.

Fatty acid oxidation and its hormonal modulation were investigated in cultured rat calvaria and in cultivated cell populations. The latter were obtained from calvaria of newborn rats by sequential time-dependent digestion with collagenase, yielding eight cell populations: the early ones containing mainly fibroblasts, the middle ones being osteoblast-like, and late ones osteoblast-osteocyte-like. In calvaria, fatty acid oxidation was increased by adding 0.1 mM- and 1.0 mM-palmitate to the medium, containing 10% (v/v) fetal-calf serum. No effect was found after parathyrin addition in vitro or when injected in vivo. All cell populations obtained by sequential digestion were found to oxidize palmitate, whereby the osteoblast-like cells showed a lower oxidation rate than the other populations. Both parathyrin and calcitonin had no effect on fatty acid oxidation. 1,25-Dihydroxycholecalciferol at 1-100 nM and 24,25-dihydroxycholecalciferol at 100 nM increased oxidation primarily in the population enriched with osteoblast-like cells. Insulin at 1.6 microM diminished it in the cell populations enriched with osteoblast-like cells and in the late bone-cell fraction. However, glucagon had no effect. The energy provided by fatty acid oxidation in this system is approx. 40-80% of glucose metabolism, suggesting that this event may be of importance in the energy metabolism of bone.     

Interaction of androgens and estrogens in the control of reproduction

Castrated male quail were injected with the synthetic oestrogen, diethylstylbestrol (DES) or the synthetic androgen, methyltrienolone (R 1881) or both compounds simultaneously. Both R 1881 and DES activated male sexual behaviour, inhibited LH and FSH secretion and increased hypothalamic aromatase activity. Additive effects between R 1881 and DES were observed for the induction of brain aromatase and for the inhibition of FSH secretion. As a consequence, mechanisms mediated by androgen and estrogen receptors must be involved in the control of these reproductive characteristics.     

Growth curves,morphology and ultrastructure of ten Paracoccidioides brasiliensis isolates

The yeast phase of ten P. brasiliensis isolates were studied to characterize their growth pattern, morphology and ultrastructure. Growth curves were determined after counts of total and viable fungi units (FU) during 20 days. Three growth patterns were observed: slow, reaching approximately 10–30× 10⁶ FU/tube (Pb 18, Pb 265 and PB 2); intermediate, reaching 60–150×10⁶ FU/tube (IVIC Pb 9, IVIC Pb 267, Pb SN, Pb Vitor and Pb Campo Grande) and fast, reaching 180–370×10⁶ FU/tube (Pb 2052 and Pb 192). The highest percentage of viable cells occurred on the 6th day of culture for Pb 192, Pb Campo Grande, Pb 2052 and IVIC Pb 9; on the 8th day for Pb Vitor, Pb SN, Pb 18 and IVIC Pb 267; on the 10th day for Pb 265 and on the 12th day of culture for Pb 2. Mean generation times varied from approximately 21.2 (Pb 2052) to 102.6 hours (Pb 265). The isolates showed similar morphology, except IVIC Pb 267 which did not present a typical yeast-phase at 35°C and the two fast-growing isolates (Pb 2052 and Pb 192) that presented smaller cell sizes and less tendency to clump. The ultrastructure of the isolates was similar: the cell walls presented a width of 0.1 to 0.2 °; the mitochondria presented few cristae and had equivalent patterns of distribution and morphology; the endoplasmic reticulum was scanty, presenting narrow cisternae; the vacuoles, empty or filled with electrondense material, were numerous and two to five nuclei with pores were constantly observed.     

Hyporheic biofilms — a potential food source for interstitial animals

Glass-beads (diam. = 250 μm) were buried 10 cm deep in the sediment of a stream. After an exposure of eight weeks, bacterial densities on the beads varied between 2.7 × 10⁵ and 2.4 × 10⁷/cm², and the length of the fungal mycelium between 0.2 and 5.3 mm/cm². Bacterial densities did not show any correlation with the DOC content of the water, but were positively correlated with respiration on the beads. Fungal mycelium was negatively correlated with water temperature. Acid hydrolysis of stream-exposed beads released sugars and amino acids, whose combined carbon content exceeded that of the microbial cells by a factor of at least 4. Gut extracts of Gammarus tigrinus and Tipula caloptera released amino acids and sugars from stream-exposed beads.     

Characteristic chromosome abnormalities,including rearrangements of 6p,del(7q), +12, and t(12;14), in 44 uterine leiomyomas

Summary The cytogenetic analysis of 224 leiomyomas from 138 patients is presented. An insufficient number of mitoses was found in 35 tumors, normal karyotypes in 145, and clonal chromosome aberrations were detected in 44. The three previously identified cytogenetic subgroups were all represented in this series: del(7) (q21.2q31.2) was found in 11, trisomy 12 in five, and t(12;14)(q14-15;q23-24) in one leiomyoma. Rearrangements of 6p, including deletions, inversions, and various translocations, were found in eight tumors, thus delineating a new cytogenetic subgroup of uterine leiomyoma. The remaining 21 karyotypically abnormal tumors had nonrecurrent changes. One leiomyoma had two cytogenetically unrelated clones characterized by del(7)(q21.2 q31.2) and +12. Karyotypic changes in two separate leiomyomas from the same uterus were identified in five patients; in three of them, different anomalies were found in the two tumors, whereas cytogenetically identical aberrations – del(7q) and dic(21;22) – were detected in two macroscopically discrete tumors. These findings suggest that whereas some multiple leiomyomas originate independently, others may be derived from the same neoplastic clone.     

Prothymosin alpha expression is associated to cell division in rat testis

Summary Using immunohistochemical methods, we have investigated the cellular distribution of prothymosin alpha (ProT) in adult rat testis. A policlonal antibody raised against thymosin alpha 1 conjugated to keyhole limpet hemocyanin was used. ProT immunoreactivity was observed in the cytoplasm and nucleus of spermatogonia and primary spermatocytes in initial phases of the first meiotic division, preleptotene, leptotene and zygotene. However, in pachytene phase they already showed a weak or negative staining. On the other hand, secondary spermatocytes, spermatids, spermatozoa and Sertoli cells were not stained. Based on this fact we suggest that ProT is present in the proliferative cycle in the final steps of G₁ phase, throughout the S and G₂ phases and in initial steps of the prophase.     

Release of copper from yeast copper-thionein after S-alkylation of copper-thiolate clusters.

Our knowledge on the release of copper from Cu-thionein in biological systems is limited. Other than oxidative cleavage or direct transfer, the possibility of an alkylation mechanism seemed attractive. Iodoacetamide and methyl methanesulphonate were successfully employed to alkylate the Cu-thiolate sulphur atom of homogeneous Cu(I)-thionein from yeast. The alkylation caused a weakening of the Cu-S bonding, which led to the release of copper. After equilibrium dialysis a proportion of the released copper was found in the dialysis buffer. When iodoacetamide was used carboxymethylcysteine was detected in the protein hydrolysate. A 10-fold molar excess over cysteine was sufficient for complete alkylation, which could be conveniently monitored by c.d. at 328 and 359 nm. The reaction proceeded under both aerobic and anaerobic conditions. E.p.r. measurements of Cu2+ revealed unequivocally the complete cleavage of the Cu-thiolate bonding in less than 5 h. It is possible that this mode of copper release might be of relevance to the molecular transport of this biochemically important transition metal.