Does an increase in the ratio of cytoplasmic NADPH to NADP+ accompanied by a decrease in the ratio of cytoplasmic NADH to NAD+ mediate the actions of insulin?

This paper proposes that both a decrease in the cytoplasmic ratio of $\text{NADH}\text{NAD}{}^{\mathrm{+}}$ and an increase in the ratio of $\text{NADPH}\text{NADP}{}^{\mathrm{+}}$ may account for many biological actions of insulin. Evidence in support of this hypothesis is discussed.     

Atheromas that cause fatal thrombosis are usually large and frequently accompanied by vessel enlargement.

Several lines of clinical evidence show that AMI frequently occurs at sites with mild to moderate degree of coronary stenosis. The degree of luminal stenosis depends on plaque deposition and degree of vessel remodeling, features poorly assessed by coronary angiography. This postmortem study tested the hypothesis that the size of coronary atheroma and the type of remodeling distinguish culprit lesion responsible for fatal AMI from equi-stenotic nonculprit lesion in the same coronary tree. The main coronary branches from 36 consecutive patients with fatal AMI were studied. The culprit lesion (Group 1) and an equi-stenotic nonculprit segment (Group 2) obtained in measurements of another coronary branch from the same patient were compared. Morphometry and plaque composition was assessed in both groups. Compared to Group 2, Group 1 had larger areas of: plaque 9.6 vs. 4.7 mm(2), vessel 12.7 vs. 7.4 mm(2) and lumen 1.7 vs. 1.2 mm(2); (P< .01). Positive remodeling was more frequent in Group 1 than Group 2: 21/30 (70%) vs. 8/26 (31%). Plaque area correlated positively with lipid core and macrophages and negatively with fibrosis and smooth muscle cells. Atherosclerotic plaques that cause fatal thrombosis are more frequently positively remodeled and tend to be larger than nonculprit plaques with the same degree of cross-sectional stenosis. We tested whether arterial remodeling and plaque size vary between segments containing a fatal thrombosed plaque versus an equi-stenotic nonculprit plaque. Culprit vessel segments had higher cross-sectional areas of intimal plaque and of vessel wall than equi-stenotic nonculprit plaques. The cross-sectional area of the vessel correlated positively with both the lipid core area and CD68(+) macrophage content, and negatively with fibrosis area and smooth muscle cell content. These results add elements explaining limitations of angiography in identifying plaques and provide new insights into the role of remodeling in plaque instability.     

Natural occurrence of Aflatoxins in commercial pepper in Iran

During the period from September to November 2014, occurrences of Aflatoxin B1, B2, G1, and G2 (AFB1, AFB2, AFG1, and AFG2) were determined in 76 pepper samples consisting black pepper (n?=?40) and red pepper (n?=?36) obtained from local markets of Isfahan province, Iran. Aflatoxins' (AFs') analyses were carried out by using the high-performance liquid chromatography (HPLC) method. AFB1 levels in 32 (88.9%) of 36 red pepper samples were higher than the Iranian and European maximum permitted level (>5?µg/kg). Total AFs were detected in 41 out of 76 samples (53.9%) while 25 pepper samples (32.9%) had levels of the toxin above the Iranian and European permitted level, that is, 10?μg/kg. This study shows that incidence of AFs' contamination in red pepper in Iran was significantly higher than black pepper (p?相似文献   

A subcritical decrease in blood concentrations of glucose induced in healthy individuals and not accompanied by any pathological manifestations.

An earlier unknown subcritical decrease in blood concentrations of glucose is described, which is not accompanied by any pathological manifestations, and proceeds on the background of normal physical activity and health of the surveyed individuals. 35 healthy volunteers, aged between 19 and 33, have been surveyed by means of the apparatus 'Artificial pancreas' of the 'Biostator' type and the meters of glucose concentrations 'Dextrometer' and 'Aiton'.     

A steady decrease in occurrence of Salmonella typhi infection in Rourkela, Orissa

Between January 1999 and December 2001, the isolation rate of Salmonella typhi in Rourkela was found to be under steady fall as compared to the isolation rate encountered between 1996 and 1998. Of 4378 blood samples tested, 254 were found positive for S. typhi giving an over all per cent positivity of 5.8. Enteric fever was found to occur almost through out the year. An over all 30.7 per cent of multi drug resistant (MDR) strains of S. typhi have appeared during this period. Proper and timely health education besides undertaking corrective measures in sanitary system and water supply management, appeared to have a cumulative effect in the steady reduction of enteric fever morbidity in this region.     

Natural haemagglutinins in mice: their occurrence and properties

The frequency and titres of natural sheep haemagglutinins in mice were greatest in the C57BL/6J strain. They did not appear until the mice were about 5 weeks old and increased with age.

The development of haemagglutinins was not prevented by neonatal thymectomy or by injection of neonates with large doses of sheep erythrocytes. Irradiation of the very young adult or treatment with 6-mercaptopurine did not appear to be effective in preventing the development of natural haemagglutinins and titres of existing haemagglutinins were unaltered by these treatments.

The natural haemagglutinins are of the 19S variety, are susceptible to mercaptoethanol treatment and do not pass from the mother to the suckling young. In contrast, agglutinins elicited by injection of sheep cells are of the 7S variety, their titres are unchanged by mercaptoethanol and they pass from the mother to the suckling young.

Similarities between these natural heterohaemagglutinins and natural ABO antibodies of man are discussed.

     

No decrease occurs in the number of COCs retrieved with repeated IVF cycles

Sir, We read with interest the paper by de Boer et al. (2004). Theauthors examined if the number of cumulus–oocyte complexes(COCs) retrieved decreases across consecutive IVF cycles,     

Cerebral cortex lesions decrease the number of bromodeoxyuridine-positive subventricular zone cells in mice

We previously showed that cortical lesions in rats increase the number of subventricular zone (SVZ) cells. Here, we examined the response of the SVZ to cortical lesions in mice from 6 h to 35 days later. Whereas the total number of cells did not change, the number of cells in S-phase (bromodeoxyuridine-positive) decreased in a biphasic manner (from 6 h to day 3, and again at days 25-35). In addition, there was a delayed (days 25-35) increase in immunoreactivity for polysialylated neural cell adhesion molecule, a marker of neuroblasts. The results suggest that in mice there are rapid as well as delayed responses in the SVZ to injury of the overlying cerebral cortex. They also show that the SVZ of different mammalian species can exhibit widely divergent responses to the same brain injury.     

Depression-like state in maternal rats induced by repeated separation of pups is accompanied by a decrease of cell proliferation and an increase of apoptosis in the hippocampus

Stressful experiences, such as an unsatisfactory mother–infant relationship after delivery, can induce depressive disorders, and it is well-known that stressors impair memory function. The hippocampus plays a crucial role in memory processes. In the present study, we determined whether a depressed-like state induced by repeated separation of pups affects the memory capability of the maternal rats. We also determined the effects of repeated separation from pups on cell proliferation, apoptosis, and serotonin expression in the brains of maternal rats. In the present results, the immobility time in the forced swim test was increased and the climbing time was decreased in the mothers separated from their pups. The latency in the step-down avoidance task was increased in the mothers separated from their pups. Also, the expressions of serotonin (5-hydroxytryptamine) and tryptophan hydroxylase in the dorsal raphe were decreased in the mothers separated from their pups. The number of Ki-67-positive cells was decreased, while the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells in the hippocampal dentate gyrus was increased in the mothers separated from their pups. Based on the present results, it is suggested that separation of pups might induce a depressed-like state in the maternal rats with reduced cell proliferation and increased apoptosis in the hippocampus, resulting in memory impairment of maternal rats.     

Age-related decrease in the number of hemopoietic stem cells and progenitors in senescence accelerated mice

Senescence accelerated mice (SAM-P) were used for the study of the possible aging of hemopoiesis. The number of peripheral leukocytes decreased significantly with age, whereas hematocrit showed only a slight decrease. Although the number of total nucleated cells in the bone marrow increased, the number of hemopoietic stem cells (CFU-S) as well as that of granulocyte-macrophage colony forming cells (GM-CFC) showed a decrease in old mice. A significant decrease in the number of GM-CFC was observed in the spleen of old SAM-P mice, whereas no decrease was found in the number of CFU-S. Such a profound reduction of the recruitment of GM-CFC from CFU-S in the spleen together with a reduction of bone marrow hemopoiesis may be responsible for the decrease in the number of peripheral leukocytes in the old mice. SAM-P mice could provide a good model for the study of the aging of hemopoietic system.     

Porcine splenic peptides (Polyerga) decrease the number of experimental lung metastases in mice

Preparations of splenic peptides under the name of Polyerga are being tested in numerous experimental immunomodulating and antitumorous models and are also used during supportive treatment of tumorous patients. Further, the incidence of experimental lung metastases of melanoma cells in mice was significantly reduced if we used Polyerga preparations. The aim of our investigation was to determine whether Polyerga is active directly against tumor cells or whether its activity is manifested by modulating immune and other possible abilities of the organism. To clarify the problem glycopeptides containing Polyerga were incubated with melanoma B16F10 cells in vitro and the plating efficiency of these cells determined when cultivated in medium, or in medium with different doses of the same Polyerga preparation. The cells preincubated in medium only reacted to the addition of increasing doses of Polyerga, 150 pg or more, by raising colonies number. However, 24-h incubation of melanoma cells in the presence of 150 μg of Polyerga per ml significantly reduced the number of tumor cell colonies in comparison to the corresponding cell cultures previously not exposed to Polyerga. These in vitro studies were extended to in vivo application using C57B1/GoZgr mice injected i.v. with melanoma cells pretreated with Polyerga in vitro or previously not treated. A group of the treated mice was further injected i.p. with Polyerga. All the mice were killed at a particular time and the number of lung nodules determined. A significant difference to the control values was noticed in each group that used Polyerga, regardless of the exposure of melanoma cells to Polyerga in vitro, in vivo or to combined treatment. The efficiency of Polyerga application 7 days following i.v. injection of control melanoma cells (cultivated in medium only) when the nodules already exist, was further evaluated in a combined treatment using DTIC, a drug of choice in melanomas. The smallest incidence of experimental lung metastases was observed in the group exposed to the combination of DTIC and Polyerga. Polyerga preparation is thus active against melanoma cells, particularly in vivo and if combined with chemotherapy.     

The number of retrieved oocytes does not decrease during consecutive gonadotrophin-stimulated IVF cycles

BACKGROUND: Our aim was to study whether there is a decreasing trend in the number of retrieved oocytes in women who had all undergone at least seven consecutive IVF cycles. METHODS: A nationwide retrospective cohort study was conducted among women whose first IVF cycle was stimulated with gonadotrophins in The Netherlands between 1983 and 1995. Among these eligible women, we identified all women who had received at least seven consecutive IVF cycles (n = 330). Poisson regression analysis was used to assess the trend in the number of retrieved oocytes over the first six IVF cycles. RESULTS: The unadjusted results showed a slight but non-significant decrease in the number of retrieved oocytes over six IVF cycles. The change in cycle 6 compared with cycle 1 was -0.06 oocytes (5.8% decrease) (P = 0.21). When adjusting for the number of ampoules and the stimulation protocol (fertility drug used combined with use of GnRH agonists), there was a considerable and highly significant decrease from cycle 1 to cycle 6 [change in cycle 6 compared with cycle 1: -0.19 oocytes (17.4% decrease), (P < 0.0001)]. However, when adjusting for age of the women, this decrease almost completely disappeared [change in cycle 6 compared with cycle 1: -0.05 oocytes (5% decrease), (P = 0.50)]. CONCLUSION: The results suggest that there is no decrease in the number of retrieved oocytes over subsequent cycles when simultaneously accounting for the increasing age of the women, differences in the number of ampoules of gonadotrophins used, type of stimulation protocol and year of IVF treatment.     

Age-related decrease in the proportion of germinal center B cells from mouse Peyer's patches is accompanied by an accumulation of somatic mutations in their immunoglobulin genes

Somatic hypermutation of immunoglobulin genes and the generation of memory B cells seems to take place in germinal centers, which are chronically present in Peyer's patches. Age-associated changes in the germinal center B cell compartment of Peyer's patches and in the mutations of a χ light chain transgene were analyzed in unimmunized mice. Somatic mutations accumulate in germinal center B cells slowly and continuously to reach an apparent plateau when the animals are around 5 months old. In contrast, the proportion of germinal center B cells reaches a maximum in very young mice (about 2 months old) and decreases progressively thereafter. These results suggest that the highly mutated B cells in older mice arise by the successive accumulation of mutations in memory cells. The data also show that the optimum time for the analysis of hypermutation of transgenes in Peyer's patches is when the mice are about 5 months old.