Intercellular communications within the rat anterior pituitary XI: an immunohistochemical study of distributions of S-100 positive cells in the anterior pituitary of the rat

The distribution of the S-100 protein cell (folliculo-stellate cell) is very important to our understanding of the regulation of the anterior pituitary. In this study, 10 intact 60-day-old male Wistar-Imamichi rats, were separated equally into two groups. One was used for immunohistochemical study, and the other for electron microscopic analysis. Immunostained pituitary sections with S-100 protein antibody were photographed using a CCD camera equipped with a computer. The S-100 protein cells were then measured using NIH image software, and the three-dimensional distribution of the cells was analyzed. The distribution of the cells observed in each serial section showed that S-100 protein cells were dense at the basal zone of the gland and at the "transitional zone" where the pars tuberalis adjoined the anterior and intermediate lobes, where they represented over 50% of the total cell population. They then decreased in number with distance from this region to mid-way towards the sagittal axis before increasing again in the tail of the gland. The population of cells also decreased with increasing distance from the "transitional zone" to the wing and with distance from the basal zone. Portal vessels entered the anterior lobe through the "transitional zone" as thick capillaries, ran through the basal surface and penetrated into the central area of the anterior lobe. In all planes, S-100 protein cells encircled the capillaries. Ultrastructural observations confirmed the light microscopic findings indicating that clusters of agranular cells were densely located at the "transitional zone" and in the pars tuberalis. The distribution pattern of the folliculo-stellate cells and the capillaries showed good agreement and the spatial relationship between these two is detailed so as to better understand hypophyseal histophysiology.     

Free polymeric bioligands in aqueous two-phase affinity extractions of microbial xylanases and pullulanase

Two reversibly soluble-insoluble polymers (viz. Eudragit S-100 and alginate) were used as free macroaffinity bioligands in polyethylene glycol (PEG)/salt two-phase systems for separation of enzymes. Incorporation of Eudragit S-100 and alginate in the PEG phase led to considerable selectivity in separation of microbial xylanases and pullulanase, respectively. Xylanase from Aspergillus niger was recovered 93% with 56-fold purification, whereas the enzyme from Trichoderma reesei and Bacillus amyloliquefaciens was obtained with 93% activity recovery (31-fold purification) and 90% activity recovery (32-fold purification), respectively. From Bacillus acidopullulyticus pullulanase, 85% enzyme activity recovery with 44-fold purification was obtained. The approach described here shows the potential of developing into a general approach for use of reversibly soluble-insoluble macroaffinity ligand in two-phase affinity extraction.     

Volumetric productivity improvement for endoglucanase of Trichoderma pseudokoingii S-38

AIMS: The objective of this study was to design an economically feasible process for endoglucanase (EG) production. METHODS AND RESULTS: Trichoderma pseudokoingii S-38 EG synthesis was studied. Initially, either glucose at 2.5, 5 or 10 g l-1, or cellulose powder (CF11) at 5 g l-1 was used as the sole carbon source. The results showed that enzyme synthesis and biomass formation were closely correlated, and both were affected by the carbon source. To improve EG volumetric product efficiency, a new technique was developed. Glucose and CF11 (2.5 and 5 g l-1, respectively) were used as initial carbon source, and glucose was added at 2.5 g l-1 day-1. EG activity, volumetric and specific EG productivities were 6.17 IU l-1, 53 IU l-1 h-1 and 114.3 IU (g cell protein)-1 h-1, respectively. Batch production in a 2-l laboratory fermenter confirmed the advantage of the technique. The product contained 10.86 IU ml-1 EG activity in 88 h. The volumetric and specific EG productivities were 123.4 IU l-1 h-1 and 177.8 IU (g cell protein)-1 h-1, respectively. CONCLUSIONS: These results suggest that optimization of the ratio of glucose to CF11 for balancing the induction and growth rate in the production of EG may lead to technical and economical benefits. SIGNIFICANCE AND IMPACT OF THE STUDY: A new technique was developed for the production of EG which improves both the volumetric product efficiency and the specific activity.     

Organization of genes required for gellan polysaccharide biosynthesis in<Emphasis Type="Italic"> Sphingomonas elodea</Emphasis> ATCC 31461

Sphingomonas elodea ATCC 31461 produces gellan, a capsular polysaccharide that is useful as a gelling agent for food and microbiological media. Complementation of nonmucoid S. elodea mutants with a gene library resulted in identification of genes essential for gellan biosynthesis. A cluster of 18 genes spanning 21 kb was isolated. These 18 genes are homologous to genes for synthesis of sphingan polysaccharide S-88 from Sphingomonas sp. ATCC 31554, with predicted amino acid identities varying from 61% to 98%. Both polysaccharides have the same tetrasaccharide repeat unit, comprised of [4)--l-rhamnose-(13)--d-glucose-(14)--d-glucuronic acid-(14)--d-glucose-(1]. Polysaccharide S-88, however, has mannose or rhamnose in the fourth position and has a rhamnosyl side chain, while gellan has no sugar side chain but is modified by glyceryl and acetyl substituents. Genes for synthesis of the precursor dTDP-l-rhamnose were highly conserved. The least conserved genes in this cluster encode putative glycosyl transferases III and IV and a gene of unknown function, gelF. Three genes (gelI, gelM, and gelN) affected the amount and rheology of gellan produced. Four additional genes present in the S-88 sphingan biosynthetic gene cluster did not have homologs in the gene cluster for gellan biosynthesis. Three of these gene homologs, gelR, gelS, and gelG, were found in an operon unlinked to the main gellan biosynthetic gene cluster. In a third region, a gene possibly involved in positive regulation of gellan biosynthesis was identified.     

Ribosomal DNA evolution and phylogeny in Aloe (Asphodelaceae)

All Aloe taxa (～400 species) share a conserved bimodal karyotype with a basic genome of four large and three small submetacentric/acrocentric chromosomes. We investigated the physical organization of 18S-5.8S-26S and 5S ribosomal DNA (rDNA) using fluorescent in situ hybridization (FISH) to 13 Aloe species. The organization was compared with a phylogenetic tree of 28 species (including the 13 used for FISH) constructed by sequence analysis of the internal transcribed spacer (ITS) of 18S-5.8S-26S rDNA. The phylogeny showed little divergence within Aloe, although distinct, well-supported clades were found. FISH analysis of 5S rDNA distribution showed a similar interstitial location on a large chromosome in all species examined. In contrast, the distribution of 18S-5.8S-26S rDNA was variable, with differences in number, location, and size of loci found between species. Nevertheless, within well-supported clades, all species had the same organizational patterns. Thus, despite the striking stability of karyotype structure and location of 5S rDNA, the distribution of 18S-5.8S-26S rDNA is not so constrained and has clearly changed during Aloe speciation.     

On the interpretation of small-angle x-ray solution scattering from spherical viruses.

The intermediates in the ribosome assembly in exponentially growing Escherichia coli have been identified by centrifuging a crude lysate, pulse-labeled with a radioactive RNA base, through a sucrose gradient and analyzing for precursor rRNA in the gradient fractions by gel electrophoresis. The major intermediate in the assembly of the 50 S subunit cosediments with the mature subunit, whereas two minor precursor species sediment between the 30 S and 50 S peaks. The assembly of the 30 S subunit proceeds via a minor intermediate sedimenting slightly behind the mature subunit and a major precursor particle that cosediments with the mature 30 S subunit.The fraction of the rRNA contained in these precursor particles was determined by direct determination of the amount of rRNA in the precursor particles, and from the labeling kinetics of their rRNA. The direct estimation indicated that about 2% of the total 23 S type RNA, and 3 to 5% of the total 16 S type RNA is harboured in precursor particles. In the kinetic experiments the specific activity of the nucleoside triphosphates and of the different ribosomal particles was followed after addition of a radioactive RNA precursor to the growth medium. The results were compared with a digital simulation of the flow of isotopes through the assembly pathways. This method indicated that approximately 2% of the total 23 S type RNA, as well as 2% of the total 16 S type RNA, is contained in the precursor particles.     

Identification and Characterization of Sulfhydryl-Containing Proteolytic Fragments Involved in the Ca2+-Induced Conformational Change of Beef Brain S-100

Abstract: The Ca²⁺-dependent conformational alteration of the brain-specific S-100 protein was studied by reacting the protein with N -ethyl[2,3-¹⁴C]maleimide in the absence and presence of Ca²⁺ and under denaturing conditions. Peptic hydrolysates of the ¹⁴C-labeled protein were analyzed and fractionated by high-performance liquid chromatography. Labeled peptide fractions were characterized by high-voltage electrophoresis and TLC. A clear distinction could be made between two classes of sulfhydryl-containing fragments: (a) neutral, hydrophobic, and (b) acidic. Ca²⁺ markedly favored ¹⁴C incorporation into the former components, whereas the latter were readily available only under denaturing conditions.     

奥沙利铂联合替吉奥胶囊治疗晚期大肠癌患者的临床疗效

目的:探讨奥沙利铂联合替吉奥胶囊治疗晚期大肠癌患者的临床疗效。方法:非盲法随机对照方法将患者分成试验组和对照组,各27例。试验组患者使用奥沙利铂联合替吉奥胶囊治疗,对照组患者使用奥沙利铂治疗,均为4个周期。评价两组治疗后的临床疗效和不良反应。结果:试验组:CR 1例,PR 11例,SD 10例,PD 5例。(CR+PR)RR 44.4%。中位疾病进展时间(TTP)9.5个月,中位生存期(MST)19.1个月。对照组:CR 0例,PR 5例,SD 8例,PD 15例。(CR+PR)RR 18.5%。中位疾病进展时间(TTP)8.6个月,中位生存期(MST)16.9个月。主要不良反应为血液毒性、胃肠道反应、外周神经炎及肝功能异常。试验组白细胞下降15例,对照组12例,试验组贫血发生为13例,对照组的为21例,试验组恶心、呕吐发生为18例,对照组为24例,试验组便秘发生为8例,对照组为15例,差异有统计学意义(P0.05)。结论:奥沙利铂联合替吉奥胶囊治疗晚期大肠癌患者相比单独使用奥沙利铂更加有效,更具优越性,不良反应更少,患者的生存质量得以改善,值得临床上推广应用。     

Cytogenetic studies in South American species of Serjania (Sapindaceae: Paullinieae)

Abstract

Serjania Mill. (Paullinieae) is considered the most important neotropical genus of Sapindaceae due to species number and its widespread distribution. In this study, 14 species belonging to three sections were analyzed using conventional staining, C/CMA/DAPI banding, and fluorescence in situ hybridization (FISH) with a 18S-5.8S-26S rDNA probe. New chromosome counts are reported for Serjania crassifolia, Serjania platycarpa, and Serjania regnellii, all with 2n = 24, which is remarkably constant for Serjania. The karyotypes are moderately asymmetric, and variations observed in A1 and A2 indices show resemblances between S. platycarpa, Serjania hebecarpa, and S. crassifolia, and between Serjania communis, Serjania gracilis, and S. regnellii. The banding pattern was homogeneous in Serjania. C/DAPI bands (AT-rich sites) were not clearly evidenced, but changes in the number and position of GC-rich sites (CMA bands) were observed. These segments were associated with 18S-5.8S-26S rDNA sites. The significance of the results is discussed in relation to chromosomal data available for the genus and in regard to the infrageneric treatment of Serjania.