Lesions of the Pancreatic Islets Produced in Cats by Administration of Glucose

Hydropic degeneration of the islands of Langerhans and permanent severe diabetes mellitus have followed the prolonged injection of intraperitoneal glucose-saline solution in normal as well as in partially depancreatized cats. Positive results were associated with prolonged hyperglycemia. These findings add further evidence in support of the hypothesis that a sustained elevation of blood glucose may, under certain conditions, lead to the production of damage to the islands of Langerhans in this species. Besides hyperglycemia, other disturbances which might be responsible wholly or in part for the island lesions are under study.     

Variation at the b Mating Type Locus of Ustilago maydis

ABSTRACT Population level diversity at the Ustilago maydis b mating type locus was determined in samples from four Minnesota locations using a combination of plate mating techniques and a polymerase chain reaction (PCR)-based assay. The PCR method allows rapid identification of b types from samples of natural populations and utilizes the hypervariable regions of the b locus that determine mating type specificity. Results demonstrated high levels of b diversity within populations, with one population yielding 17 of the total 18 b types found in the study. Pairwise G(ST) values were in the range of 0.02 to 0.05, and common b mating types were found across broad geographic distances. These data demonstrated that very low levels of differentiation among U. maydis populations occur with respect to b locus variation. Consistent with frequency-dependent selection models, b types were represented at approximately equal frequencies within the entire Minnesota population. However, neutral evolutionary models for patterns of geographic distribution and variation at b cannot be entirely excluded. The importance to agricultural practices of understanding population genetic processes is discussed.     

Rapid and early changes in morphology and gene expression in soya bean seedlings emerging in the presence of neighbouring weeds

Light signalling is an important mechanism of plant competition during the early stages of seedling development. Far‐red‐enriched (FR‐E) light reflected from neighbouring weeds has been shown to induce the shade avoidance response leading to changes in plant morphology and increased variability in yields. In this study, the morphological and molecular changes occurring at the hypocotyl arch and primary leaf stage of soya bean development were investigated in response to FR‐E light reflected from neighbouring weeds. A reduction in the root/shoot was identified at the hypocotyl arch stage, and an increase in height was detected at the unifoliate stage of soya bean seedlings. In addition, FR‐E light induced a change in the expression profile of reactive oxygen species (ROS)‐scavenging genes. Early in seedling development, ROS‐scavenging genes were upregulated. However, this trend was reversed at later stages of development with downregulation of several ROS‐scavenging genes. These results demonstrated the rapidity of induction of the shade avoidance response and that gene expression in soya bean seedlings was dependent upon developmental stage and tissue type sampled.     

猪败血型链球菌病的诊疗报告

本文阐述了猪链球菌病的临床症状、实验室检验及防治方法，力求为科学防控猪链球菌病提供有益的探索和参考。     

Collagen polypeptides: normal release from polysomes in the absence of proline hydroxylation

It is not necessary that proline be hydroxylated for the completion and release of nascent collagen chains from polysomes. Hydroxylation of collagen proline in vivo normally takes place predominantly on nascent polypeptides; however, in the presence of an inhibitor of hydroxylation, unhydroxylated chains are released. These chains may subsequently be hydroxylated when the inhibition is removed. The results clarify a controversy over the site of proline hydroxylation.     

Antifungal activities of mono- and di-SCCl3 substituted compounds: Structure-activity correlations

The mono- and di-N-SCCl₃ substituted derivatives of lactams, cyclic urea, 5,5-diphenylhydantoin and 5-ethyl-5-phenylbarbituric acid were synthesized. Many of these compounds have not been reported previously. The antifungal activities were determined by spore germination method using Stemphylium sarcinaeforme, Monilinia fructicola, Helminthosporium maydis and Alternaria solani. Among the lactam and cyclic urea derivatives studied 1,3-bis(trichloromethylthio)-2-imidazolidinone appears to be the most active compound against S. sarcinaeforme, and has activity slightly below those of the commercial products captan and folpet. Among the diphenylhydantoin and phenobarbital derivatives the mono-SCCl₃ compounds appear to be more potent than the disubstituted compounds in most of the cases examined, but they are not as active as the imidazolidinone derivative. The antifungal activity appears to be highly dependent on the lipophilic character as measured by the 1-octanol/water partition coefficient. Since the bis-SCCl₃ compounds are less potent than the mono-substituted compounds in both of the series of compounds studied, it is evident that the whole molecule rather than any decomposition products of the N-SCCl₃ moiety is responsible for the fungitoxicity.