A histological study of the hypophysial-gonadal system during sexual maturation and spawning in the milkfish, Chanos chanos (Forskal)

The pituitary gland of the milkfish, Chanos chanos , was studied at different stages of sexual maturation and spawning. Consecutive median sagittal sections were treated with a range of stains to demonstrate the different cell types and regions. The milkfish pituitary consists of a neural component, the neurohypophysis, and an epithelial component, the adenohypophysis, which in turn consists of three regions: the rostral pars distalis (RPD), proximal pars distalis (PPD), and pars intermedia (PI). However, unlike most teleosts, the pituitary gland of the milkfish is encased in a bony chamber, has dorsal and ventral lobes and extends anteriorly from its point of origin at the base of the brain. PAS (+) basophils are found in all regions of the adenohypophysis, but mostly in the proximal pars distalis. These cells undergo hypertrophy and hyperplasia during sexual maturation, shrinkage and degranulation during spawning.     

Uptake of free amino acids by the diatom,Melosira mediocris

Individual ¹⁴C-labelled amino acids are rapidly removed from dilute solution in artificial sea water (0.2 mol 1^–1) by suspensions of Meliosira medocris. The rate of disappearance of radioactivity corresponds closely to removal of primary amines as determined by measurement of the rate of decrease of fluorescamine-positive material. Net removal of naturally occurring free amino acids from the sea water habitat from which the alga was isolated is demonstrated using high performance liquid chromatography. Removal of amino acids from natural sources makes a significant contribution to the carbon requirements of the alga as well as supplying significant amounts of amino nitrogen.     

The complete amino-acid sequence of the proteinase inhibitor B from the root of the arrowhead (Sagittaria sagittifolia L.)

After reduction and alkylation of the disulfide bonds of the proteinase inhibitor B from the root of the arrowhead (Sagittaria sagittifolia L.) followed by CNBr cleavage three peptide fragments with 68, 62 and 11 amino-acid residues could be separated on DEAE-Sepharose CL-6B. The peptides or the inhibitor itself were further specifically cleaved either by trypsin or by the mixture of (CH3)2SO/HCl/HBr at the arginyl- and the tryptophyl-peptide bond, respectively. The complete amino-acid sequences of the peptides were determined by manual solid phase DABITC/PITC double coupling micro-method and the primary structure of the arrowhead inhibitor B consisting of 141 amino-acid residues was then elucidated. Twenty pairs of amino-acid residues are repeated in the molecule of this inhibitor, three of these pairs even occur three times. The possible locations of the reactive sites are discussed. On the basis of sequence comparisons between this inhibitor and all other serine proteinase inhibitors the arrowhead inhibitor may belong to a new family.     

Preparation of bovine blood coagulation factors X1 and X2

A method is described for the preparation of both Factor X1 and Factor X2 from citrated bovine blood. The proteins from the plasma were first adsorbed on barium citrate by adding barium chloride solution. The precipitate formed was stirred with citrate/NaOH pH 6.9 buffer; barium and other clotting factors were removed by adding ammonium sulphate (up to 30% saturation) to the suspension. The Factor X was then precipitated by 65% ammonium sulphate, after resolution in citrate buffer chromatographed on DEAE-Sephadex and purified by rechromatography on DEAE-Sephadex and DEAE-Sepharose, respectively. This yielded Factor X1 and Factor X2 with respective purifications of about 16 000 and 24 000-fold that of the plasma. The apparent molecular mass of both Factor X1 and Factor X2 was 55 kDa as estimated by the sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Factor X2 had a higher specific biological activity of about 340 000 units/mg compared to that of Factor X1 of about 230 000 units/mg.     

Effects of exercise on insulin binding and glucose metabolism in muscle

To elucidate the mechanism of enhanced insulin sensitivity by muscle after exercise, we studied insulin binding, 2-deoxy-D-[1-14C]glucose (2-DOG) uptake and [5-3H]glucose utilization in glycolysis and glycogenesis in soleus and extensor digitorum longus (EDL) muscles of mice after 60 min of treadmill exercise. In the soleus, glycogenesis was increased after exercise (P less than 0.05) and remained sensitive to the action of insulin. Postexercise insulin-stimulated glycolysis was also increased in the soleus (P less than 0.05). In the EDL, glycogenesis was increased after exercise (P less than 0.05). However, this was already maximal in the absence of insulin and was not further stimulated by insulin (0.1-4 nM). The disposal of glucose occurred primarily via the glycolytic pathway (greater than 60%) in the soleus and EDL at rest and after exercise. The uptake of 2-DOG uptake was not altered in the soleus after exercise (4 h incubation at 18 degrees C). However, with 1-h incubations at 37 degrees C, a marked increase in 2-DOG uptake after exercise was observed in the soleus (P less than 0.05) in the absence (0 nM) and presence of insulin (0.2-4 nM) (P less than 0.05). A similar postexercise increase in 2-DOG uptake occurred in EDL. Despite the marked increase in glucose uptake and metabolism, no changes in insulin binding were apparent in either EDL or soleus at 37 degrees C or 18 degrees C. This study shows that the postexercise increase of glucose disposal does not appear to be directly attributable to increments in insulin binding to slow-twitch and fast-twitch muscles.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bovine serum albumin: characterization of a fatty acid binding site on the N-terminal peptic fragment using a new spin-label

A new spin-label, 4-(L-glutamo)-4'-[(1-oxy-2,2,5,5-tetramethyl-3L-pyrrolidinyl )amino]-3, 3'-dinitrodiphenyl sulfone, is shown to bind to one high-affinity binding site on bovine serum albumin (K = 5 X 10(4) M-1, n = 1). Analysis of the binding of the spin-label to the amino-terminal half (peptic fragment PB) and the carboxy-terminal half (peptic fragment PA) of BSA, and their complex (PA-PB), indicates that the spin-label binds to a long-chain fatty acid binding site located on PB. The usefulness of the novel specificity of the spin-label in characterizing this binding site is discussed.     

子宫颈糜烂病毒病因的探讨

491份宫颈拭子病毒分离结果表明:糜烂宫颈单纯疱疹病毒(HSV)分离阳性率(30.8％)是正常宫颈(2.6％)的11.8倍,用人干扰素治疗一个疗程后,病毒分离率下降至疗前的1/4.36例糜烂宫颈活体组织DNA分子杂交表明,乳头瘤病毒16型(HPV-16)阳性者占52.8和,HPV-18占17.9％,HPV-6B占28.1％,HPV-11占7.7％,251例宫颈糜烂患者经人(?)D型基因工程干扰素双盲对比治疗后,总有效率达93.8％,显效率达60％,分析临床疗效与HSV分离率的变化表明,临床有效病例中有35％(49/140)在治疗后病毒阴转,有57％在疗前疗后均未分离出HSV,有5％在疗前疗后保持阳性不变,有2.9％疗前阴性,疗后阳性,上述结果表明,HSV和HPV与慢性宫颈炎有一定关系。     

赤霉素产生菌~#85104菌株原生质体的形成再生和紫外光对原生质体诱变条件的研究

赤霉产生菌在正常条件下不产生孢子,育种材料以多核菌丝体及其碎片为主,大部分常用的诱变剂对它们诱变效应较差。本文报导有关赤霉素产生菌~#85104菌株原生质体的获得、再生和紫外光诱变原生质体的条件,甘氨酸对菌丝体生长的影响,以及采用二硫苏糖醇预处理菌丝体等方面条件的研究。在采用紫外光照射原生质体的诱变处理下,已获得数株高产的新菌株。     

Population structure and dynamics of Pinus massoniana Lamb. on mount Jinyun,Sichuan, China

Masson Pine (Pinus massoniana Lamb.) is a pioneer in forest succession in the subtropics of East Asia. However, the species persits, though with decreasing abundance, throughout the various successional phases. Agestructure, spatial pattern, density, population biomass, and their dynamics are described for a population in Sichuan, China, on the basis of a census of all individuals in the population while substituting space with time. In the course of succession, the population density increases and its rate of growth decreases until self-thinning starts; during the phase of self-thinning density decrease and continues to decrease even afterwards, but the rate of growth increase markedly after self-thinning has stopped. The development of population biomass (Bp) during the early succession from shrub-grassland to the early stages of mixed pine and broad-leaved forest can be described by a logistic equation. Later, Bp decrease rapidly. These changes are governed partly by inherent biological features of P. massoniana and partly by the invasion, establishment and development of shade-tolerant evergreen broad-leaved trees. Both self- and alien-thinning occur. Soil conditions affect the rates of these processes.