Influence of Androgenicity on Adipocytes and Precursor Cells in Female Rats

We examined the effects of overexposure of testosterone (T) on fat cell morphology and adipocyte precursor pools in inguinal and retroperitoneal fat depots of ovariectomized rats. In both tissues peripubertal T decreased weights without affecting adipocyte mean cell size or the size distribution profiles, but adipocyte number was decreased by 65% in the inguinal and by 38% in the retroperitoneal depots. Immunofluorescent flow cytometry utilizing a specific antibody to rat adipose tissue lipoprotein lipase was used to quantify regional precursor cell populations. T sharply reduced the percentages of differentiated and undifferentiated preadipocytes in the inguinal depot, from 43.2 ± 5.3 to 23.5 ± 2.1% and from 57.7 ± 4.0 to 43.6 ± 5.3%, respectively, with a concomitant increase in fibroblasts from 1.6 to 32.9%. On the other hand, T had no effect on retroperitoneal preadipocyte pools. Perinatal andro-genization exacerbated the decline in the inguinal weight (1.4 ± 0.1 vs. 2.2 ± 0.1g) but otherwise did not influence the actions of peripubertal T. Androgens may thus act in a tissue-specific manner to regulate fat cell growth potential in the femoral region in the female.     

Biological Parameters for Four Coccinellid Species in Central Saudi Arabia

Developmental and reproductive rates ofAdonia variegataGoeze,Coccinella novemnotataHerbst,C. septempunctataL., andC. undecimpunctataL. were studied in wheat and barley in Central Saudi Arabia. Beetles were reared in the laboratory at 25 ± 2°C onBrevicoryne brassicae(L.) andRhopalosiphum padiL.A. variegataandC. undecimpunctatahad significantly higher egg hatching (X = 81.8 and 74.5%), adult longevity (X = 71.8 and 70.0 days), and survival (X = 61.8 and 61.5%), respectively.Coccinella undecimpunctatahad the highest fecundity (X = 370.5 eggs/female) and longest oviposition period (X = 29.8 days).C. septempunctataexhibited the lowest values for these biological parameters. No differences were evident in the total developmental time or egg and pupal duration, although species differences occurred in the larval duration. Larvae ofA. variegatadeveloped faster (X = 11.8 days) than Larvae ofC. septempunctata(X = 12.0 days),C. undecimpunctata(X = 12.2 days), orC. novemnotata(X = 13.1 days). The intrinsic rate of increase (r_m) and predicted population density were higher forC. undecimpunctata(X = 0.093 and 98553) after 60 days than forC. novemnotata(X = 0.088 and 59405),C. septempunctata(X = 0.086 and 35033), orA. variegata(X = 0.082 and 37991), respectively.     

Photosynthetic Nitrite Reduction as Influenced by the Internal Inorganic Carbon Pool in Air-Grown Cells of Synechococcus UTEX 625

Photosynthetic reduction of NO2- was studied in air-grown cells of a cyanobacterium, Synechococcus UTEX 625. Addition of NO2- resulted in significant amounts of chlorophyll a fluorescence quenching both in the absence and presence of CO2, fixation inhibitors, glycolaldehyde or iodoacetamide. The degree of NO2- quenching was insensitive to the O2 concentration in the medium. Addition of 100 [mu]M inorganic carbon in the presence of glycolaldehyde and O2, leading to formation of the carbon pool within the cells, resulted in pronounced fluorescence quenching. Removal of O2 from the medium restored the fluorescence yield completely, and the subsequent addition of NO2- quenched 36% of the variable fluorescence. From the response to added 3-(3,4-dichlorophenyl)-1,1-dimethylurea, the quenching by NO2- appeared to be photochemical quenching, and nonphotochemical quenching did not seem to be present. The reduction of NO2- observed on its addition to inorganic carbon-depleted cells remained uninfluenced by O2 or glycolaldehyde. The internal inorganic carbon pool in the cells stimulated NO2- reduction, both in the presence and absence of O2, by 4.8-fold. An increase in NO2- reduction by 0.5-fold was also observed in the presence of O2 during simultaneous assimilation of carbon and nitrogen in inorganic carbon-depleted cells. Contrary to this, under anaerobiosis, NO2- reduction was suppressed when carbon and nitrogen assimilation occurred together.     

Evaluation of the weed flora of Egypt from Predynastic to Graeco-Roman times

Macrofossils of weeds retrieved from archaeological sediments in Egypt are discussed in terms of their presence, preservation and representation significance. The study reveals 112 field weeds from 61 archaeological sites dating from Predynastic times (4500 B.C.) up to the Graeco-Roman period (A.D. 395). Most of the remains were preserved by desiccation. The 112 listed species include 24 taxa from Predynastic Hierakonpolis (3800–3500 B.C.) identified for the first time. This study is based on a selection of 97 species from the entire list. Interpretation of field weed finds from the archaeological contexts is discussed. The highest number of species, 63, is recorded from the Pharaonic period. The Predynastic era is represented by 46 species and the Graeco-Roman period by 34. The intensive archaeological excavation of Pharaonic settlements may explain the rich flora of that period compared with the two others. Floristic analysis shows that 57 species were introduced in association with crops from the Middle East and 40 may belong to the native vegetation of the Nile valley.     

A Genetic and Mosaic Analysis of a Locus Involved in the Anesthesia Response of Drosophila Melanogaster

We describe a genetic and behavioral analysis of several alleles of har38, a mutant with altered sensitivity to the general anesthetic halothane. We obtained a P-element-induced allele of har38 and generated several excision alleles by remobilizing the P element. The mutants narrow abdomen (na) and har85 are confirmed to be allelic to har38. Besides a decreased sensitivity to halothane, all mutant alleles of this locus cause a characteristic walking behavior in the absence of anesthetics. We have quantified this behavior using a geotaxis apparatus. Responses of the mutant alleles to different inhalational anesthetics were tested. The results strongly favor a multipathway model for the onset of anesthesia. Mosaic flies were tested for their response to halothane and checked for their abnormal walking behavior. The analysis suggests that both the behaviors are exhibited only by such mosaics as have the entire head of mutant origin. It is likely that this focus represents an element of a common pathway in the anesthetic response to several inhalational anesthetics but not all. This result is the first demonstration of regional specificity in the CNS of any animal for general anesthetic action.     

Purification and Characterization of a Human Brain Galectin-1 Ligand

Abstract: Our previous studies have characterized an endogenous lectin from human brain identified as galectin-1. A soluble ligand of galectin-1 was purified from human brain by affinity chromatography and preparative electrophoresis. The purified ligand (termed HBGp82, for human brain galectin-1-binding polypeptide of 82,000 daltons) has an apparent molecular mass of 82 kDa and is glycosylated by N -linked biantennary complex structures. HBGp82 was partially characterized by microsequencing of peptide fragments. Similar peptides were found in a heat shock of protein of 90,000 daltons, hsp90. However, comparison of apparent molecular weights and matrix-assisted laser desorption mass spectrometry clearly showed that HBGp82 differs to some degree from hsp90.     

Proteolytic activity of proteasome on myofibrillar structures

The physiologic function of proteasome remains unclear. Evidence suggests a role in degradation of ubiquitin-protein conjugates, MHC antigen presentation, and some specificity of substrate within certain cell types. To explore further the properties of proteasome we have examined its effect on a well defined structure, the myofibril. We find that despite its large size (20S) proteasome is able to degrade myofibrils and intact, permeabilized muscle fibrils. The proteins degraded showed some specificity because actin, myosin and desmin were degraded faster than -actinin, troponin T and tropomyosin. Changes in ultrastructure were slow and included a general loss of structure with Z and I bands effected before the M band and costameres.     

Spatial relationships between the anterior centriole and the mitotic center during interphase in the amoebae of the myxomycete Physarum polycephalum

Amoebae of the Myxomycete Physarum polycephalum in the interphase state typically contain only one proflagellar apparatus in which the anterior kinetosome (anterior centriole) is attached to the microtubule organizing center 1 (mtoc 1). We built strains possessing more than one mtoc 1 and a variable number of anterior centrioles to allow the appearance of new structures. In 8% of the amoebae of these strains, the 1:1 attachment between the anterior centriole and the mtoc 1 is not always respected. In nine cases studied using tridimensional reconstructions from ultrastructural thin sections, the pattern of attachment was more complex. A mtoc 1 could be linked to several anterior centrioles, and/or reciprocally an anterior centriole could be linked to several mtoc 1. In one case, an anterior centriole was not linked to a mtoc 1 and in three cases, a single centriole exhibited anterior and posterior characteristics. These observations suggest that (1) each pair of centrioles constitutes a morphological and physiological entity that is distinct from the mitotic center (mtoc 1); (2) the attachment of the anterior centriole to the mtoc 1 occurs at the end of each mitosis; (3) there is an inductory process during the morphogenesis of the link between the anterior centriole and the mtoc 1; (4) the anterior characteristics of a centriole can be present in the absence of the link with the mtoc 1; (5) the anterior and posterior characteristics of a centriole are not exclusive of each other, ruling out the existence of a lineage corresponding to the anterior centriole and a lineage corresponding to the posterior centriole; and (6) the differences between anterior and posterior centrioles result from a maturation process.     

Separation, isolation and amino acid composition of uremic peptides

Gel filtration and thin layer chromatography were conducted on sera from uremic patients and normal subjects for the isolation of nitrogenous substances unique to uremia. Many ninhydrin-positive substances were found in greater amounts in uremic patients compared to normal subjects. Some of these ninhydrin-positive substances were also detected by staining with chlorine-tolidine. Amino acid analysis of these substances showed considerable qualitative and quantitative differences, perhaps reflecting interference with enzymatic activity by the uremic environment.