Sporulation in yeast consists of two highly coordinated processes. First, a diploid cell that is heterozygous at the mating-type locus undergoes meiosis, in which one round of DNA replication is followed by two rounds of nuclear division. Second, the meiotic products are packaged into spore cells that remain within the mother cell. A large number of genes are induced specifically during sporulation, and their products carry out different sporulation-specific events. Expression of these sporulation-specific genes is controlled by several regulators which function at different stages of the sporulation program, resulting in a cascade of gene expression following induction of meiosis. Here we describe one sporulation-specific gene, SSP2, which is induced midway through meiosis. Ssp2 shows significant homology to the predicted product of a hypothetical ORF in Candida albicans. Homozygous mutant ssp2 diploid cells fail to sporulate. In the mutant background, meiotic recombination and nuclear divisions remain normal; however, viability declines rapidly. Following meiosis, ssp2 cells form the prospore membrane, but fail to form the outer layer of the spore wall. The Ssp2 protein localizes to the spore wall after meiosis II. In addition, the ssp2 defect is also associated with delayed and reduced expression of late sporulation-specific genes. Our results suggest that SSP2 function is required after meiosis II and during spore wall formation.
The liver of the mature male rat contains a moderate affinity (Kd = 10(-8)M), low-capacity, cytoplasmic androgen binding protein (CAB) whose appearance during puberty and disappearance during senescence correlate with the androgen-dependent synthesis of alpha 2u-globulin. Molecular properties of CAB were examined by photoaffinity labeling with tritiated methyltrienolone (R-1881), a synthetic androgen, and by its localization within the hepatocytes which are competent to produce alpha 2u-globulin. Photoaffinity labeling of the liver cytosol derived from postpubertal male rats, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography, showed a predominant androgen binding band corresponding to Mr 31,000. This 31-kilodalton (kDa) binding component was conspicuously absent in the liver of androgen-insensitive prepubertal and senescent male rats and in adult male rats treated with estradiol-17 beta. In addition, unlike the cytoplasmic extract, the nuclear lysate of the male rat hepatocytes did not contain the 31-kDa androgen binder. Disappearance of the 31-kDa androgen binding band from the cytosolic fraction of androgen-insensitive animals was associated with a concomitant appearance of a minor androgen binding component of apparent Mr 29,000. The livers of postpubertal male rats normally contain two subpopulations of hepatocytes, only one of which is highly active (competent) in alpha 2u-globulin synthesis. Separation of these two subpopulations through a fluorescence-activated cell sorter followed by whole cell labeling showed more than a 2-fold higher uptake of R-1881 by the competent cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Total cystectomy with Roux-en-Y hepaticojejunostomy for choledochus cyst often causes malabsorption and other problems as a result of jejunal biliary diversion bypassing the duodenum. Restoration of near normal anatomy can only return the normal physiological harmony and assure normality. A simple antirefluxing hepaticoduodenostomy has proved successful.
A prospective study of 48 women was carried out to estimate the incidence of common genital pathogens in women referred to colposcopy clinic requiring diathermy loop excision and to compare patient morbidity in the subgroups with and without genital pathogens. Of the 43 women included in the analysis, genital pathogens were present in 24 cases (56%) and absent in 19 (44%) of the 24 positive cases, 19 (79%) women had pathogen(s) on the cervical swab, 24 (100%) had pathogen(s) on the high vaginal swab and 15 (63%) had both a positive cervical and high vaginal swab (HVS). The most frequently isolated groups of organisms were mixed anaerobes, alone (four HVS and four cervical) or in combination with Gardnerella vaginalis (four HVS and three cervical) or coliforms (two HVS and two cervical). The mean duration of bleeding and vaginal discharge in the two study groups was not statistically significant (t value 1.97, P 0.05; and t value 0.48, P 0.5, respectively). However, the mean duration of bleeding graded by the patient as being moderate to severe was significantly different in the two groups (t value 3.18 P 0.01). Fifty-six per cent of the women in the study had confirmed genital pathogens, predominantly anaerobes, and the prolonged moderate-to-severe bleeding in this group suggests a potential role for prophylactic bacteriocides, although the study size was unable to implicate a single pathogen.
IntroductionThyroid hormones (TH) influence the growth and development of the maturing mammalian brain via specific nuclear receptors, while their role in normal functioning of the adult mammalian brain is unclear. However, adult-onset of dysthyroidism develops a number of functional and neuropsychological disorders in adult humans [1]. In contrast to the developing brain, most of the changes developed in adults are reversible with the proper adjustment of circulatory TH.Recently, the idea of direct non-genomic actions of TH in adult neurons is interesting. These include distribution, concentration, metabolism and binding of L-triiodothyronine (L-T 3 ) [1,2] in the synaptosomes of adult rat cerebral cortex and indicate crucial role of TH in neuronal functions in adult mammals. Although TH-mediated calcium entry in adult rat brain synaptosomes [3,4], and in hypothyroid mouse cerebral cortex [5] have been reported, its synaptic functions in adult neurons in dysthyroidism are unclear. Calcium-influx is an important physiological function in brain, following which cascades of membrane events occur that ultimately lead to neurotransmitter release and follow up neural functions. Disruption in this crucial membrane event may lead to various neuropsychological disorders that depend on calcium. Present study demonstrates a regulation and homeostatic mechanism of calcium accumulation within cerebrocortical synaptosomes of hypothyroid adult rat. Materials and MethodsMaterials L-Triiodothyronine (L-T 3 ), 6-n-propylthiouracil (PTU), disodium-ATP, quin-2, bovine serum albumin (BSA), sodium azide, 2-mercaptoethanol, EDTA and EGTA were purchased from Sigma Chemical Co., USA. All other chemicals were of highest reagent grade. Animal treatmentAdult male Charles Foster rats (12 weeks) were housed at 25 18C in 12 h dark-12 h light conditions and fed ad libitum with standard rat diet and water. Hypothyroidism was induced by i.p. injections of PTU (20 mg/kg b.w.) for 14 days. Serum L-T 4 and L-T 3 levels were measured by radioimmunoassay [6]. Preparation of synaptosomesThe animals were sacrificed quickly by decapitation, brains were removed and cerebral cortices were dissected out in ice-cold condition. The synaptosomes from the cerebral cortex were prepared as described [6]. Briefly, the cerebral cortex was homogenized (10 % w/v) in 0.32M sucrose and centrifuged at 1000 g for 10 minutes to remove cell debris and nuclei. The supernatant was collected and re-centrifuged at 1000 g for another 10 min. The resulting supernatant was layered over 1.2 M sucrose, and centrifuged at 34000 g for 50 min at 48C. The fraction collected between the 0.32 M and 1.2 M sucrose layer was diluted at 1:1.5 ratio with ice-cold bidistilled water, further layered on 0.8M sucrose, and again centrifuged at 34 000 g for 30 min. The pellet thus obtained was washed, repelleted at 20 000 g for 20 min. Intact synaptosomes were used for the experiments.
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