Uptake of dehydroascorbic acid in high-GSH and normal-GSH dog erythrocytes

Uptake of dehydroascorbic acid (DHA) was studied in two types of dog erythrocytes with high GSH and normal GSH levels. Compared with ascorbic acid uptake, DHA produced a much greater ascorbic acid accumulation in dog erythrocytes. Both dog erythrocytes showed a concentration dependence of DHA uptake, and cellular ascorbic acid concentrations were significantly higher in high-GSH cells than in normal-GSH cells. Glucose and cytochalasin B inhibited DHA uptake. This suggests that DHA enters dog erythrocytes predominantly by the facilitated glucose transporter, particularly by the Glut 1 glucose transporter. The rate of glucose uptake was quite similar in the two types of cells. Compared with normal-GSH cells, high-GSH cells were more resistant to oxidative stress induced by high concentration of DHA. As a rapid entry of DHA inflicts on cells a heavy demand for GSH for its reduction to ascorbic acid, high-GSH cells containing a larger reserve of GSH have an advantage over normal-GSH cells in both ascorbic acid accumulation and resisting oxidative stress produced by DHA.     

Pivotal function for cytoplasmic protein FROUNT in CCR2-mediated monocyte chemotaxis

Ligation of the chemokine receptor CCR2 on monocytes and macrophages with its ligand CCL2 results in activation of the cascade consisting of phosphatidylinositol-3-OH kinase (PI(3)K), the small G protein Rac and lamellipodium protrusion. We show here that a unique clathrin heavy-chain repeat homology protein, FROUNT, directly bound activated CCR2 and formed clusters at the cell front during chemotaxis. Overexpression of FROUNT amplified the chemokine-elicited PI(3)K-Rac-lamellipodium protrusion cascade and subsequent chemotaxis. Blocking FROUNT function by using a truncated mutant or antisense strategy substantially diminished signaling via CCR2. In a mouse peritonitis model, suppression of endogenous FROUNT markedly prevented macrophage infiltration. Thus, FROUNT links activated CCR2 to the PI(3)K-Rac-lamellipodium protrusion cascade and could be a therapeutic target in chronic inflammatory immune diseases associated with macrophage infiltration.     

Frequent cellular senescence in small bile ducts in primary biliary cirrhosis: a possible role in bile duct loss

The pathogenesis of progressive bile duct loss in primary biliary cirrhosis remains unclear. In this study, the involvement of cellular senescence of biliary epithelial cells was examined in liver tissue samples from patients with primary biliary cirrhosis (n = 33), and compared with control diseased and normal livers (n = 83). In addition, cellular senescence was induced by oxidative stress in cultured mouse biliary epithelial cells. Biliary epithelial cells in small bile ducts in primary biliary cirrhosis, especially those in patients presenting with chronic non-suppurative cholangitis, frequently expressed senescence-associated beta-galactosidase, and senescence-associated p16(INK4) and p21(WAF1/CIP). In contrast, senescence-associated markers were rarely expressed in small bile ducts in control livers. The infiltration of myeloperoxidase-positive inflammatory cells into biliary epithelial cell layers was closely associated with the cellular senescence of biliary epithelial cells in early-stage PBC. Cellular senescence of cultured mouse biliary epithelial cells was induced by treatment with H2O2 via the p38MAPK-dependent pathway and nitric oxide-augmented H2O2-induced cellular senescence. Oxidative stress- and nitric oxide-mediated cellular senescence may be involved in bile duct lesions, which are followed by progressive bile duct loss in primary biliary cirrhosis.     

A longitudinal study of postpartum depressive symptoms: multilevel growth curve analyses of emotion regulation strategies, breastfeeding self-efficacy, and social support

Postpartum depression is a serious health issue affecting as many as 10-15 % of postpartum women. This longitudinal study aimed to explore how psychological variables such as cognitive emotion regulation strategies, breastfeeding self-efficacy (BSE), and dimensions of social support predicted postpartum depressive symptoms (Edinburgh Postnatal Depression Scale). The data were collected with web-based survey questionnaires between May 2008 and December 2009, in a sample of 737 new mothers. The same questionnaire was surveyed at three points in time: 6 weeks, 3 months, and 6 months postpartum. Data were analyzed using multilevel modeling (level 1, time points; level 2, person). Results showed that BSE, certain cognitive emotion regulation strategies, perceived available support, and need for support predicted the rate of postpartum depressive symptoms. Only breastfeeding self-efficacy predicted change in postpartum depressive symptoms. This study illustrates the importance of psychological variables with regard to postpartum depressive symptoms. Implications for preventative efforts are discussed.     

The Y chromosome of the Okinawa spiny rat, Tokudaia muenninki, was rescued through fusion with an autosome

The genus Tokudaia comprises three species, two of which have lost their Y chromosome and have an XO/XO sex chromosome constitution. Although Tokudaia muenninki (Okinawa spiny rat) retains the Y chromosome, both sex chromosomes are unusually large. We conducted a molecular cytogenetic analysis to characterize the sex chromosomes of T. muenninki. Using cross-species fluorescence in situ hybridization (Zoo-FISH), we found that both short arms of the T. muenninki sex chromosomes were painted by probes from mouse chromosomes 11 and 16. Comparative genomic hybridization analysis was unable to detect sex-specific regions in the sex chromosomes because both sex probes highlighted the large heterochromatic blocks on the Y chromosome as well as five autosomal pairs. We then performed comparative FISH mapping using 29 mouse complementary DNA (cDNA) clones of the 22 X-linked genes and the seven genes linked to mouse chromosome 11 (whose homologue had fused to the sex chromosomes), and FISH mapping using two T. muenninki cDNA clones of the Y-linked genes. This analysis revealed that the ancestral gene order on the long arm of the X chromosome and the centromeric region of the short arm of the Y chromosome were conserved. Whereas six of the mouse chromosome 11 genes were also mapped to Xp and Yp, in addition, one gene, CBX2, was also mapped to Xp, Yp, and chromosome 14 in T. muenninki. CBX2 is the candidate gene for the novel sex determination system in the two other species of Tokudaia, which lack a Y chromosome and SRY gene. Overall, these results indicated that the Y chromosome of T. muenninki avoided a loss event, which occurred in an ancestral lineage of T. osimensis and T. tokunoshimensis, through fusion with an autosome. Despite retaining the Y chromosome, sex determination in T. muenninki might not follow the usual mammalian pattern and deserves further investigation.     

stx genotype and molecular epidemiological analyses of Shiga toxin-producing Escherichia coli O157:H7/H? in human and cattle isolates

The relationship between human diseases caused by infection with Shiga toxin (Stx)-producing Escherichia coli (STEC) O157 strains and O157 strains isolated from cattle was investigated in an area where stockbreeding is prolific. For this purpose, the stx genotypes, the molecular epidemiological characteristics of 268 STEC O157 strains including 211 human-origin strains and 57 cattle-origin strains, and clinical manifestations of 210 STEC-infected people were analyzed. Of 211 human-origin strains, 92 strains (44%) were of the stx1/stx2 genotype, and 74 strains (35%) were of the stx2c genotype. Most of the people infected with stx2c genotype strains presented no symptoms or mild symptoms such as slight diarrhea, except for 3 patients with bloody diarrhea. Of the 57 cattle-origin strains, 27 strains (47%) were of the stx2c genotype and 17 strains (30%) were of the stx1/stx2 genotype. Pulsed-field gel electrophoresis (PFGE) and insertion sequence (IS) analysis demonstrated that 11 isolates (41%) of the 27 cattle isolates of the stx2c genotype had high homology (>95% identity) with human isolates. These results suggest that some genetic patterns of the stx2c genotype strains might be preserved in cattle or their surrounding environment for several years, and during these periods, they might have opportunities to infect people through various routes. Because of the mild virulence of the stx2c genotype strains, they seemed to be transmitted asymptomatically from cattle to humans and then spread from person to person. It may be a public health concern. Further, they occasionally cause severe symptoms in humans; therefore, caution is warranted for infections by stx2c genotype O157 strains, in addition to stx2-possessing genotype O157 strains.     

C-reactive protein levels in the serum of asthmatic patients.

BACKGROUND: Asthma is a chronic airway inflammatory disease caused by immune cells such as T lymphocytes and eosinophils. Recently, highly sensitive C-reactive protein (hs-CRP) assays have become available for detecting small changes in CRP levels within the reference range, allowing for the evaluation of clinical inflammation. OBJECTIVE: To investigate the relationship between hs-CRP levels and bronchial asthma. METHODS: We collected blood samples from 109 patients with bronchial asthma, with or without attacks, and measured serum eosinophil cationic protein levels, pulmonary function, and serum CRP levels using an hs-CRP assay. RESULTS: Mean serum hs-CRP levels were significantly higher in patients without attacks (0.473 mg/L) and with attacks (0.908 mg/L) (P < .001 for both) than in controls (0.262 mg/L). Serum hs-CRP levels were inversely correlated with forced expiratory volume in 1 second/forced vital capacity in asthmatic patients (r = -0.4915; P < .01). CONCLUSION: Serum hs-CRP levels may be related to the state of asthma exacerbation and allergic inflammation.     

Effects of hPTH (1-34) and Gosha-jinki-gan on the trabecular bone microarchitecture in ovariectomized rat tibia

Although human parathyroid hormone (1-34) [hPTH (1-34)] was reported to improve osteoporotic bone loss, little is known about the anti-osteoporotic effect of the traditional Chinese medicine, Gosha-jinki-gan (GJG). The purpose of this present study was to clarify and compare the effects of hPTH (1-34) and GJG on trabecular bone microarchitecture in ovariectomized (OVX) rat tibia by using microcomputed tomography (micro-CT). Thirty 12-week-old Sprague-Dawley female rats were underwent ovariectomy (OVX) or sham operation. Four weeks later, the ovariectomized rats were further divided into OVX, OVX + PTH, and OVX + GJG groups. hPTH (1-34) was administered subcutaneously at a dose of 20 microg/kg, 3 times/week, and OVX + GJG group received 0.05% aqueous solution of GJG as the only drinking fluid for 8 weeks respectively. The three-dimensional (3D) trabecular microarchitecture of the bone in the proximal tibial metaphysis was evaluated by micro-CT. In the OVX + PTH group, trabecular bone volume (BV/ TV), number (Tb.N) and thickness (Tb.Th) were significantly increased, structure model index (SMI) and trabecular bone pattern factor (TBPf) decreased when compared with the OVX group. In comparison to the OVX group, BV/TV and Tb.N were significantly greater, while SMI and TBPf had no marked changes in the OVX + GJG group. These results suggest that the administration of hPTH (1-34) restore the trabecular bone volume and improve the microstuctural property as well, while GJG reduce the bone loss without affecting its microstructural property in ovariectomized rats.     

In vivo visualization and portally repeated transplantation of bone marrow cells in rats with liver damage

Recent reports have raised concerns over the feasibility of differentiating bone marrow cells (BMCs) into functional hepatocytes. Such augmentation is considered necessary for potential clinical use of these cells in liver diseases. The present investigation was designed to determine the kinetics of transplanted BMCs and evaluate the effects of repeated bone marrow transplantation (BMT) in rat models of CCl(4)-induced liver damage. The early kinetics of transplanted BMCs was evaluated with a charge-coupled-device (CCD) camera using BMCs obtained from green fluorescent protein (GFP) transgenic (Tg) rats and followed up with in vivo imaging system (IVIS) using BMCs obtained from firefly luciferase (luc) Tg rats. We used a portal infusion system for repeated BMT. BMCs were transplanted via a peripheral vein or the portal vein (PV) once or repeatedly using this system. The results revealed that BMCs accumulated more in the damaged liver than in the intact liver. In the experimental group receiving repeated BMT via the PV, the liver fibrosis was milder than that in the group not receiving BMT, and large clusters of albumin-producing cells were detected by albumin staining. The injected BMCs were shown to accumulate in the damaged liver. This strategy of repeated BMT has potential clinical use in enhancing the number of albumin-producing cells and suppressing liver fibrosis. This combination of beneficial effects may contribute to the benefits of cell transplantation therapy. Demonstration of the benefits of BMT in this study may be expected to have great significance for clinical trials.