[Study on the role and possible mechanism of hemeoxygenase-1/carbon monoxide system in protection of quercetin against ethanol-induced hepatocytes oxidative injury]

Objective: To study the protective effect and potential mechanism of heme oxygenase (HO-1)/carbon monoxide (CO)-mediated quercetin on alcoholic oxidative damage of primary rat hepatocytes. Methods: Primary rat hepatocytes were isolated and cultured by two-step collagenase technique. Ethanol exposed primary rat hepatocytes were simultaneously added with quercetin (100 μmol/L) and/or hemoglobin (100 μmol/L) or different doses of CO-releasing molecules (CORM-2, 5-50 μmol/L) for their combined action. After polling, LDH, AST activities and MDA and GSH levels were measured in the supernatant of cell culture. The alone or combined effects of quercetin, CORM-2, hemoglobin and zinc protoporphyrin IX exposed to ethanol were detected by the activity of CYP2E1 in liver microsomes. Statistical analysis of data was performed by analysis of variance (ANOVA) and intergroup comparison was done by SNK-test. Results: Simultaneous addition of 100 μmol/L quercetin had significantly reduced ethanol-induced AST and LDH release, and GSH consumption and MDA elevation extent. Moreover, quercetin had not only lost the hemoglobin (CO blocker) protective effect but also had further exacerbated ethanol-induced lipid peroxidation. CORM-2 had reduced ethanol-induced AST and LDH release, and GSH consumption and MDA production in liver cells, and thus had dose-dependent protective effect. Ethanol had increased significantly CYP2E1 activity. Quercetin or CORM-2 had inhibited CYP2E1 activity, while hemoglobin or protoporphyrin IX had eliminated quercetin inhibitory effect and had increased the CYP2E1 activity. Quercetin, and CYP2E1 activity was constant as compared to ethanol group when CORM-2, zinc protoporphyrin IX and ethanol were incubated with hepatocytes, but the CYP2E1 activity was significantly decreased (P < 0.05), and the differences were statistically significant. Conclusion: CO/HO-1 metabolite mediates the protective effect of quercetin on alcoholic oxidative damage of hepatocytes, which may be related to the inhibition of CYP2E1 activity.

Is vertebroplasty a risk factor for subsequent vertebral fracture, meta-analysis of published evidence?

In our paper, we systemically retrieved the eligible study evaluating whether increased incidence of subsequent vertebral fracture is associated with vertebroplasty. Main effect sizes were vertebral fracture rates reported in terms of hazard ratio (HR) for time-to-event data or relative risk (RR) for dichotomous outcome. Our results do not support the hypothesis that vertebroplasty contributes to increased risk of subsequent vertebral fracture, neither adjacent nor total vertebral fracture.

INTRODUCTION

Vertebroplasty has been implicated in significant changes in vertebral strength, vertebral shape, and consequently increased risk for subsequent vertebral fracture, especially the adjacent level. Here, we further tested the hypothesis whether new-onset vertebral fracture is a natural result of osteoporosis or consequence of cement augmentation.

METHODS

Relevant literatures were retrieved using PubMed, Web of Knowledge, and Cochrane Central Register of Controlled Trials (CENTRAL), supplemented by a hand-search of the reference lists of selected articles. Eligible studies assessed whether increased morbidity of subsequent vertebral fracture is associated with vertebroplasty. Main effect sizes were vertebral fracture rates reported in terms of hazard ratio (HR) for time-to-event data or relative risk (RR) for dichotomous outcome. Random-effects model was used to account for clinical or methodological heterogeneity across studies.

RESULTS

Thirteen studies with a number of 2,551 individuals (1,631 in vertebroplasty group and 920 in control group) were suitable for this meta-analysis. In trials that reported adjacent vertebral fracture as time-to-event data (two trials, n = 328), we found a similar incidence of vertebral fracture in percutaneous vertebroplasty (PVP) group compared to conservative therapy (HR 0.60, 95% confidence interval 0.29 to 1.26; P = 0.18). In trials that reported overall vertebral fracture as time-to-event data (three trials, n = 704), vertebroplasty was associated with a slightly increased but non-significant risk for vertebral fracture (HR 1.14, 95% confidence interval 0.65 to 2.00; P = 0.65). The outcome was further confirmed in the secondary meta-analysis of studies that reported vertebral fracture as dichotomous data. Subgroup analysis according to study design revealed no difference either.

CONCLUSIONS

Our results do not support the hypothesis that vertebroplasty contributes to increased risk of subsequent vertebral fracture, neither adjacent nor total vertebral fracture. However, adequately designed randomized controlled trials are warranted to confirm the present findings.

Effect of amino acids on the eutectic behavior of NaCl solutions studied by DSC

The effect of a series of amino acids on the eutectic behavior of NaCl solutions at isotonic concentration has been studied by differential scanning calorimetry. The inclusion of different amino acids had different effects on eutectic formation. The amino acids were grouped into four categories based on their effect on eutectic formation: category C were amino acids that had no effect on eutectic formation; category D amino acids inhibited eutectic formation; category T amino acids shifted the melting of the eutectic to a lower temperature; category E amino acids caused the formation of a new eutectic with a melting temperature approximately -5 degrees C. The mechanism of these different effects on eutectic behavior is discussed, based on the chemical structure of the amino acids.

Expression of human Fas ligand on mouse beta islet cells does not induce insulitis but is insufficient to confer immune privilege for islet grafts

Fas (CD95) and Fas ligand (FasL/CD95L) are involved in programmed cell death and the regulation of host immune responses. FasL has been shown to provide immune privilege, thus prolonging the survival of unmatched grafts in a variety of tissues, such as eyes and testis. In murine FasL (mFasL) transgenic mice, FasL provoked granulocyte infiltration and insulitis in the pancreas. We intended to study whether the expression of human FasL, instead of mFasL, on mouse beta islet cells could avoid granulocyte infiltration, and whether islet cells transgenic for FasL could be used in islet transplantation. We produced transgenic mice in which the human FasL transgene was driven by rat insulin promoter and was expressed exclusively in the pancreas islet cells in ICR mice. In contrast to mFasL transgenic mice, histochemical staining showed that the pancreas was intact in human FasL transgenic ICR mice. However, when human FasL transgenic islet cells were transplanted into allogeneic mice with streptozotocin-induced diabetes, human FasL appeared not to prolong graft survival. Intensive granulocyte infiltration into the islet grafts was observed in recipients (Balb/c mice) which received islet grafts from human FasL transgenic mice, but not from nontransgenic, allogeneic ICR mice on day 31. Our observations suggest that FasL alone is insufficient to confer immune protection, and that other environmental factors might contribute to the formation of immune privilege sites in vivo

Enhanced secretion of IFN-gamma by activated Th1 cells occurs via reverse signaling through TNF-related activation-induced cytokine

Growing evidence has demonstrated that members of TNF superfamily transduce signals after engagement with their receptors. TNF-related activation-induced cytokine (TRANCE), a member of TNF superfamily, is preferentially expressed on the surface of activated CD4(+) Th1 cells. The soluble receptor activator of NF-kappaB (RANK).Fc fusion protein suppresses IFN-gamma secretion by activated Th1 cells, but does not affect IL-4 secretion by Th2 cells. The suppressive effect on IFN-gamma secretion is observed when Th1 cells are activated by APCs, but not by immobilized anti-TCR beta mAb. In contrast, immobilized RANK.Fc fusion protein augments IFN-gamma secretion by Th1 cells, indicating the occurrence of reverse signaling through TRANCE during T cell/APC interaction. The enhanced secretion of IFN-gamma mediated via TRANCE correlates with the activation of p38 mitogen-activated protein kinase and is blocked by SB203580, a p38 mitogen-activated protein kinase-specific inhibitor. Thus, in addition to its role in activating dendritic cells by binding to the receptor RANK, TRANCE itself can signal the augmentation of IFN-gamma secretion via a p38-dependent pathway, and this provides yet another example of reverse signaling by a member of TNF superfamily.

Functional implication of human serine/threonine kinase, hAIK, in cell cycle progression

Protein phosphorylation is involved in many biological activities and plays important roles in cell cycle progression. In the present study, we identified a serine/threonine kinase, hAIK, from human hepatic cells using degenerated polymerase chain reactions with a pair of primers derived from the highly conserved sequence in the catalytic domain of kinases. The full-length hAIK cDNA was then obtained, which contained 403 amino acids and was homologous to Drosophila Aurora2 and yeast Ipl1 proteins. Northern blotting analysis revealed that hAIK was highly expressed in the testis but not in other tissues. Expressions of hAIK drastically increased in cancer tissues/cell lines but not in fibroblasts or nontumorigenic cell lines. The recombinant hAIK protein phosphorylated itself and histone H1; this phosphorylation activity was totally abolished after a point mutation at the catalytic domain (hAIKm). During the interphase cell, hAIK was found mainly in the cytoplasm; during mitosis hAIK accumulated at the centrosomes. In addition, overexpression of hAIK in cancer cell lines (HEK293T and HeLa) appeared to inhibit cell cycle progression. None of these phenomena were observed in hAIKm whose kinase activity was rendered inactive. Our results suggest that hAIK protein/activity might modulate cell cycle progression by interacting with the centrosomes and/or proteins associated with these structures.

Heat treatment prevents postharvest geotropic curvature of asparagus spears (Asparagus officinalis L.)

Negative geotropic curvature of fresh asparagus spears after harvest was prevented by a brief heat treatment. The heat treatment was immersion in heated water at 47.5 degrees C for 2-5 min and cooling to storage temperature as soon as possible after heat treatment. The heat treatment can be varied from 45 degrees C for longer than 5 min to 50 degrees C for 2.5 min or less to avoid significant loss of spear appearance. The treatment temperature and time needed to be adjusted for spear diameter, small diameter spears required a shorter exposure time or lower temperature.

[Experimental study of R plasmid eliminating action of Coptis chinensis on E. coli]

The R plasmid curing experiment was performed in vitro with E. coli strain E. 102 bearing R plasmid as target bacteria and Coptis chinensis as elimination agent. The influence of different time on R plasmid elimination was also observed. Results showed that when the acting time was 24 hours, the cure rate of R plasmid was 2.42% and when the acting time increased to 48 hours, the cure rate elevated to 22.57%. The Missing patterns of R plasmid might be occurred in disappearence of either multiple or single resistance.

Recurrent carcinoma of the vagina following Okabayashi's radical hysterectomy for cervical carcinoma

Between 1962 and 1976, 1847 cases of cervical cancer were treated by Okabayashi's radical hysterectomy. Of these, 42 cases developed vaginal invasive carcinoma and 5 developed vaginal intraepithelial carcinoma thereafter, giving a recurrence rate of 2.5%. The vaginal recurrence rate declined annually during the period 1962-1976, and was thought to be due to the efficacy of routinization of postoperative vaginal cuff irradiation. Of the 47 recurrent cases 33 were discovered within 2 years following the operation. Seventy-two percent of the recurrent cases were asymptomatic. The importance of close follow-up of the patients during the first 2 postoperative years was denoted. The incidence of developing a secondary vaginal cancer in the cases of cervical adenocarcinoma was 10.0%, higher than the 2.2% for squamous cell carcinoma. All the recurrent cases were treated with vaginal cuff irradiation, either alone or with external irradiation and/or chemotherapy. The 3-year survival rate of the patients who had vaginal recurrence alone was 40.0%, better than that of the cases accompanied with recurrence at the other sites.

Vagina invasion by cervical carcinoma

Seventy patients with cervical carcinoma who underwent radical hysterectomy and pelvic lymphadenectomy were evaluated to assess spread to the vagina. The overall vaginal invasion rate was 34.2% (24/70), with 36% (21/58) by squamous cell carcinoma, 25% (2/8) by adenocarcinoma and 25% (1/4) by adenosquamous carcinoma. A high vaginal invasion rate (45.7%) was noted in cases in which the cervical lesion was greater than 21 mm (p less than 0.05). Combined parametrial extention (45%) and combined lymph node metastasis (33.3%) were significantly higher in the vaginal invasion cases. The diagnostic accuracy of colposcopy and the Schiller test was 80% and 67% respectively. Histologically, the course of vaginal invasion by squamous cell carcinoma could be divided into : a) continuous invasion (16/21), b) incontinuous invasion via vessel permeation (3/21) and c) combined invasion (2/21). Both cases of vaginal invasion by adenocarcinoma were noted to spread by vessel permeation. Of the 7 cases of vessel permeation, colposcopic examination was positive in only one case. A high percentage of parametrial involvement and lymph node metastasis was noted in the vessel permeation type.

Postharvest Variation in Cell Wall-Degrading Enzymes of Papaya (Carica papaya L.) during Fruit Ripening

Pectin methylesterase (PME), polygalacturonase (PG), xylanase, cellulase, and proteinase activity were determined and related to respiration, ethylene evolution, and changes in skin color of papaya (Carica papaya L.) fruit from harvest through to the start of fruit breakdown. PME gradually increased from the start of the climacteric rise reaching a peak 2 days after the respiratory peak. PG and xylanase were not detectable in the preclimacteric stage but increased during the climacteric: during the post climacteric stage, the PG declined to a level one-quarter of peak activity with xylanase activity returning to zero. Cellulase activity gradually increased 3-fold after harvest to peak at the same time as PME, 2 days after the edible stage. Proteinase declined throughout the climacteric and postclimacteric phases. A close relationship exists between PG and xylanase and the rise in respiration, ethylene evolution, and softening. Cultivar differences in postclimacteric levels of enzymic activity were not detected.An inhibitor of cellulase activity was detected in preclimacteric fruit. The inhibitor was not benzyl isothiocyanate (BITC). BITC did inhibit PG activity, though no inhibitor of PG activity was detected in preclimacteric homogenates when BITC was highest. The results indicate that inhibitors did not play a direct role in controlling wall softening.