Early macrophage infiltration in mice treated with low-dose streptozocin decreases islet superoxide dismutase levels: prevention by silica pretreatment.

It has been hypothesized that streptozocin (STZ) given in low doses for 5 consecutive days produces diabetes by induction of peroxidation phenomena similar to those induced by free radicals. Moreover, it has been demonstrated that macrophages are among the first to invade the pancreatic parenchyma and destroy islet B cells supposedly by the release of interleukin-1 that induces free radical formation. Superoxide dismutase (SOD) is a free radical scavenger present in cells, and islet B cells are known to have extremely low levels of this enzyme. Therefore, our aim was to observe SOD activity concomitantly with the appearance of intra-islet macrophages, in early diabetes induced by low-dose streptozocin (LDS). Silica-pretreated mice showed SOD values which were comparable to those found in control animals. In LDS-only-treated mice we found that SOD levels were decreased even after only 4 days from the last STZ injection and that it is at this time that the first 'recruited' macrophages appear in the islets. Moreover, the SOD levels found at this early stage (animals were still normoglycaemic and therefore not as yet diabetic) were similar to levels found by us in a previous work, in prediabetic Bio Breeding rats, thereby ascribing a crucial factor to the lowering of SOD levels even in LDS-induced diabetes.     

The in vitro adherence of murine eosinophils, neutrophils and non-induced and induced macrophages to infective larvae of Toxocara canis (Nematoda, Ascarididae)

Infective larvae of the parasite nematode Toxocara canis were incubated in vitro with murine eosinophils, neutrophils and non-induced and induced macrophages. The interactions between the different types of cells and the worms were observed in the presence or absence of immune mouse serum and/or complement. Cells showed considerable differences in the manner, duration and outcome of this interaction. Despite the adhesion of cells to the larvae of T. canis, there was no evidence of damage to the worms. Scanning and transmission electron microscopic observations suggest that the cells adhere to the cuticular surface via an electron-dense material. This material might play a protective role against the helmintotoxic capacity of the inflammatory cells.     

Isolation of SPO12–1 and SPO13–1 from a Natural Variant of Yeast That Undergoes a Single Meiotic Division

ATCC4117 is a strain of S. cerevisiae that undergoes a single nuclear division during sporulation to produce asci containing two diploid ascospores (Grewal and Miller 1972). All clones derived from these spores are sporulation-capable and, like the parental strain, form two-spored asci. In this paper, we describe the genetic analysis of ATCC4117. In tetraploid hybrids of vegetative cells of the ATCC4117 diploid and a/a or α/α diploids, the production of two-spored asci is recessive. From these tetraploids, we have isolated two recessive alleles, designated spo12–1 and spo13–1, each of which alone results in the production of asci with two diploid or near-diploid spores. These alleles are unlinked and segregate as single nuclear genes. spo12–1 is approximately 22 cM from its centromere; spo13–1 has been localized to within 1 cM of arg4 on chromosome VIII. This analysis also revealed that ATCC4117 carries a diploidization gene allelic to or closely linked to HO, modifiers that reduce the number of haploid spores per ascus and alleles affecting the total level of sporulation.     

Euphorigenic drugs: effects on the reward pathways of the brain.

This report summarizes a number of experiments designed to examine the changes in the threshold for intracranial self-stimulation (ICSS) in the rat after the administration of morphine and a number of narcotic agonist-antagonists, as well as three nonnarcotic drugs that have extensive nonmedical use (cocaine, d-amphetamine, and phencyclidine). The results of these experiments clearly indicate that morphine lowers the threshold for ICSS and, furthermore, there appears to be little or no tolerance to this effect. The only mixed agonist-antagonist that consistently lowered the ICSS threshold was pentazocine. Cocaine, d-amphetamine, and to a lesser degree, phencyclidine also lowered the ICSS threshold. These results suggest that the abuse liability of these agents may be directly related to their ability to sensitize the neural substrate involved with natural reward.     

Effect of ethyl acetate on the transport of sodium and glucose in the hamster small intestine in vitro.

The effect of ethyl acetate on Na+, water and glucose transport, as well as on glucose and electrolyte intracellular concentrations in everted and cannulated sacs of hamster jejunum, have been studied.Ethyl acetate, a substance that easily penetrates and delivers energy to the cell, strongly stimulates net glucose and Na+ transport. The explanation of the experimental results takes into account the possibility of the existence of an active extrusion of glucose at the level of the basolateral membrane of the enterocyte.     

Effect on ethyl acetate on the transport of sodium and glucose in the hamster small intestine in vitro

The effect of ethyl acetate on Na⁺, water and glucose transport, as well as on glucose and electrolyte intracellular concentrations in everted and cannulated sacs of hamster jejunum, have been studied.Ethyl acetate, a substance that easily penetrates and delivers energy to the cell, strongly stimulates net glucose and Na⁺ transport.The explanation of the experimental results takes into account the possibility of the existence of an active extrusion of glucose at the level of the basolateral membrane of the enterocyte.     

Validity of the reduced version of the Morningness-Eveningness Questionnaire

Sleep and Biological Rhythms - The aim of the present work was to validate the reduced version of the Morningness-Eveningness Questionnaire (MEQr) using circadian motor activity as external...