Ultrastructural evaluation of the effect of endosulfan on mice kidney

In this study, the effect of the endosulfan on mice kidney was investigated at ultrastructural level. Moreover, biochemical analyses (G6PD, CAT, SOD, GSH and MDA) were determined in supernatant of kidney tissue. Endosulfan (13mg/kg/day body weight) was administered orally to mices via intragastric-during 10 days. The presence of mitochondrial degeneration in cytoplasm of proximal convoluted tubule cells were a striking feature. Furthermore, there was lipofuscin granules and membranous structures in some of proximal convoluted tubule cells. In some glomeruli, ultrastructural changes such as fusion in pedicels and focal thickening at glomerular basal membrane were seen. There were cytoplasmic bulges in some distal convoluted tubule cells. The biochemical results of the experimental group were significant when compared to the control. The effect of the endosulfan was mainly on the proximal convoluted tubule cells. Morever, the other parts of the nephron were effected. Thus, this degeneration in kidney may be thought that oxidative stress may play a role to the mediator in changing configuration of cell membrane and seem to account for the morphologic alteration of kidney.     

Yeast Cdk1 translocates to the plus end of cytoplasmic microtubules to regulate bud cortex interactions

The budding yeast spindle aligns along the mother- bud axis through interactions between cytoplasmic microtubules (CMs) and the cell cortex. Kar9, in complex with the EB1-related protein Bim1, mediates contacts of CMs with the cortex of the daughter cell, the bud. Here we established a novel series of events that target Kar9 to the bud cortex. First, Kar9 binds to spindle pole bodies (SPBs) in G(1) of the cell cycle. Secondly, in G(1)/S the yeast Cdk1, Cdc28, associates with SPBs and phosphorylates Kar9. Thirdly, Kar9 and Cdc28 then move from the SPB to the plus end of CMs directed towards the bud. This movement is dependent upon the microtubule motor protein Kip2. Cdc28 activity is required to concentrate Kar9 at the plus end of CMs and hence to establish contacts with the bud cortex. The Cdc28-regulated localization of Kar9 is therefore an integral part of the program that aligns spindles.     

Defective brain development in mice lacking the Hif-1alpha gene in neural cells

Hypoxia-inducible factor 1alpha (HIF-1alpha) is essential for vascular development during embryogenesis and pathogenesis. However, little is known about its role in brain development. To investigate the function of HIF-1alpha in the central nervous system, a conditional knockout mouse was made with the Cre/LoxP system with a nestin promoter-driven Cre. Neural cell-specific HIF-1alpha-deficient mice exhibit hydrocephalus accompanied by a reduction in neural cells and an impairment of spatial memory. Apoptosis of neural cells coincided with vascular regression in the telencephalon of mutant embryos, and these embryonic defects were successfully restored by in vivo gene delivery of HIF-1alpha to the embryos. These results showed that expression of HIF-1alpha in neural cells was essential for normal development of the brain and established a mouse model that would be useful for the evaluation of therapeutic strategies for ischemia, including hypoxia-mediated hydrocephalus.     

Effect of age on susceptibility to post-traumatic infection in the elderly

Previous work has demonstrated an age-related decline in neutrophil function, including a decline in phagocytic capacity, with age in healthy individuals. This decline in function may contribute to increased susceptibility to bacterial infections in the elderly population. The present study has investigated the effects of age on susceptibility to infection and neutrophil function in elderly humans following mild trauma. Specifically, we have measured neutrophil function in 44 patients, all of whom had no significant co-morbidity, were over 65 years old (mean age 82.5 years) and had sustained a fractured neck of femur. We obtained neutrophils and examined the process of microbial engulfment by phagocytosis and the bactericidal mechanism of superoxide production. In the 5-week period after trauma, almost half of the elderly trauma patients succumbed to bacterial or fungal infection, with a predominance of chest and urinary tract infections. When examining neutrophil function, a decline in superoxide production was observed in neutrophils from the elderly trauma group at the time of hip fracture when compared with those from healthy elderly controls, and this was maintained 5 weeks after trauma. This was accompanied by an age-related reduction in phagocytic function during this period. We propose that trauma and an age-related decline in neutrophil function combine to decrease the immune response to bacteria in the elderly.     

Benefit of migration in a female sika deer population in eastern Hokkaido,Japan

The major factors affecting migration in large herbivores have been shown to be access to food resources and the risk of predation. Three migratory types of deer (resident, north migrant and east migrant) occur within a wintering female sika deer (Cervus nippon) population in eastern Hokkaido, Japan. We tested the hypothesis that north and east migrants feed on a higher quality diet than residents during summer, based on analyses of fecal nitrogen content. Fresh fecal pellets were collected in 18 summer ranges in the wintering area, northern area and eastern area between 1–5 August 2000. Fecal nitrogen content for all sampling sites was positively correlated with elevation, but was not correlated with distance from the wintering area. North migrants that inhabited higher (above 300m elevation) summer ranges fed on a higher quality diet than residents. In contrast, the dietary quality of east migrants that migrated over a long distance and inhabited lower (below 300m elevation) summer ranges was similar to that of residents. We conclude that east migrants may have gained significant benefit from the use of agricultural pastures with low population density conditions and without hunting; however, the recent population control program has reduced this benefit by avoiding the use of pasturelands.     

Transblot and cytochemical identification of avidin-interacting proteins in mitochondria of cultured cells

Cell lysates prepared from 3T3-L1 cells were analyzed by western blotting using the avidin-biotin complex system and anti-Bax antibody. The antibody interacted with bands of proteins with estimated molecular weights of 120, 74, 72, and 25 kDa. However, only the 25-kDa band was detected with the anti-Bax antibody when the direct immunoblotting method was used. Peroxidase-conjugated avidin interacted with the 120-, 74-, and 72-kDa bands. This interaction was not limited to 3T3-L1 cells, because peroxidase-avidin also interacted with these three proteins in MC3T3-E1, YROS, Saos-2, MG63, SCCKN, and SCCTF cells although the staining intensity was different in each cell type. Avidin-peroxidase also interacted with these three proteins in the mitochondria-containing fractions prepared from 3T3-L1 cells. FITC-streptavidin was also localized in mitochondria in the cultured cells. The localization of avidin/streptavidin-interacting proteins in mitochondria was confirmed by using double staining with FITC-streptavidin and Mito-tracker.     

Monitoring the cellular activity of a cultured single cell by scanning electrochemical microscopy (SECM). A comparison with fluorescence viability monitoring

The respiratory activities of cultured HeLa cells were monitored at a single cell level using scanning electrochemical microscopy (SECM) that produces images of the localized distribution of oxygen around the cell. The change in the cellular activity was traced after exposures to KCN, ethyl alcohol and the antibiotic drug, Antimycin A. The results were compared with those from the conventional fluorescence monitoring using Calcein-AM that is sensitive to deformation of the cell membrane. The SECM-based measurement follows the decrease in the cellular activity upon exposure to KCN and Antimycin A more rapidly than the fluorescence-based measurements, demonstrating that SECM is suitable for studying the cellular influence of respiration inhibitors.     

A critical role for a Rho-associated kinase, p160ROCK, in determining axon outgrowth in mammalian CNS neurons

We tested the contribution of the small GTPase Rho and its downstream target p160ROCK during the early stages of axon formation in cultured cerebellar granule neurons. p160ROCK inhibition, presumably by reducing the stability of the cortical actin network, triggered immediate outgrowth of membrane ruffles and filopodia, followed by the generation of initial growth cone-ike membrane domains from which axonal processes arose. Furthermore, a potentiation in both the size and the motility of growth cones was evident, though the overall axon elongation rate remained stable. Conversely, overexpression of dominant active forms of Rho or ROCK was suggested to prevent initiation of axon outgrowth. Taken together, our data indicate a novel role for the Rho/ROCK pathway as a gate critical for the initiation of axon outgrowth and the control of growth cone dynamics.     

Membrane enzyme systems responsible for the Ca(2+)-dependent phosphorylation of Ser(27), the independent phosphorylation of Tyr(10) and Tyr(7), and the dephosphorylation of these phosphorylated residues in the alpha-chain of H/K-ATPase

H/K-ATPase preparations (the G1 membrane) from pig stomach contain both kinases and phosphatases and show reversible phosphorylation of Tyr(7), Tyr(10), and Ser(27) residues of the alpha-chain of H/K-ATPase. The Tyr-kinase is sensitive to genistein and quercetin and recognized by anti-c-Src antibody. The Ser-kinase is dependent on Ca(2)(+) (K(0.5) = 0.9 microM), sensitive to a PKC inhibitor, and recognized by antibodies against PKCalpha and PKCbetaII. The addition of 3-[(3-cholamidopropyl)dimethylammonio]-1-propane-sulfonic acid (CHAPS) caused a dramatic increase in the phosphorylation of added synthetic copolymer substrates and permitted the phosphorylation of maltose-binding proteins fused with the N-terminal domain of alpha-chains. The phosphotyrosine phosphatase was inhibited by vanadate. The phosphoserine phosphatase was inhibited by okadaic acid and by inhibitor-2. The presence of protein phosphatase-1 was immunologically detected. Column chromatographic separation of CHAPS-solubilized G1 membrane and others indicate the apparent molecular weight of the Src-kinase to be approximately 60 kDa, the PKCalpha and/or PKCbII to be approximately 80 kDa, the Tyr-phosphatase to be 200 kDa, and PP-1 to be approximately 35 kDa. These data show that these membrane-bound enzyme systems are in sufficiently close proximity to be responsible for reversible phosphorylation of Tyr(7), Tyr(10), and Ser(27) of the catalytic subunit of membrane H/K-ATPase in parietal cells, the physiological role of which is unknown.