Evaluation of oxidative stress during apoptosis and necrosis caused by D-galactosamine in rat liver

Eighteen and twenty-four hours after intraperitoneal administration of D-galactosamine (1g/kg body weight) to rats, the activity of caspase-3-like protease in the liver increased significantly compared with that in the control group given saline. Histological examinations including the in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method found apoptotic hepatocytes 18 hr after the administration of D-galactosamine. Caspase-3 activity was barely detectable in the plasma of control rats, but increased significantly 24 hr after drug administration along with a dramatic increase in glutamate-oxaloacetate transaminase (GOT). These results indicated that D-galactosamine causes apoptosis in the liver by activating caspase-3, which is released to the plasma by secondary necrosis. The concentration of lipid hydroperoxides in the liver increased significantly 24 hr after D-galactosamine administration. In contrast, the concentration of vitamin C in the liver decreased significantly 18 and 24 hr after D-galactosamine administration. These results suggest that D-galactosamine induces severe oxidative stress in the liver, leading to extensive necrosis.     

The effect of repeated sevoflurane anesthesia on hepatic function and immunological system

BACKGROUND: Sevoflurane is known as a useful and safe anesthetic because of its properties of fast uptake and elimination at the lungs and of no effects on hepatic function. In this study we examined the effect of repeated sevoflurane anesthesia on hepatic function and immunological system. METHODS: Eight patients (ASA, PS 2 or 3) received sevoflurane anesthesia three times in 6 months. Six patients had emergency operation for injuries. Aspirate transaminase (AST), alanine transaminase (ALT) and complements (CH50, C3, C4) were measured prior to anesthesia, and 1, 7 and 14 days after anesthesia. RESULTS: The values of AST and ALT were high prior to anesthesia at the first anesthesia. However, these were of no significant changes. CH50, C3, C4 increased significantly after the first anesthesia. However, there were no significant changes of these complements after the second and the third anesthesia. CONCLUSIONS: Our results suggest that sevoflurane is not likely to provide adverse effects on the liver and to suppress the production of complements accompanied by the surgical stress.     

Postoperative recurrence of venous thromboembolism in patients with episodes of preoperative thromboembolism

BACKGROUND: Venous thromboembolism (VTE) has become a major health problem in Japan. METHODS: We examined, postoperative recurrence of VTE in patients with preoperative venous thromboembolic events and evaluated factors that are relevant to the occurrence of postoperative VTE. RESULTS: Forty-four cases out of 38500 had been diagnosed preoperatively as having VTE in the period of 1995-2001 at Kitasato University Hospital. Postoperative VTE was detected in four patients (9%) out of these 44 cases. Patients who had thrombophilia (antiphosholipid syndrome) or recent episode of VTE within 1 month were higher in the incidence of postoperative recurrence of VTE than the others. Temporary infra-vena cava filters were placed to prevent pulmonary thromboembolism in twelve patients. In 8 of the patients, thrombi were detected in or at the filter before explantation. Three patients (7%) had undergone thrombolysis therapy. Postoperative VTE was not found in patients who had already received anticoagulant therapy (warfarin) for 3 or more months. CONCLUSIONS: It is concluded that newly developed VTE occurred perioperatively in 9% of patients with preoperative VTE, and that thrombophilia and a recent episode of VTE were considered as risk factors of perioperative VTE. Temporary infra-vena cava filters are a valuable device for prevention of postoperative pulmonary thromboembolism.     

Correlation between number of renal cysts and aortic circumferences measured using autopsy material

Although the presence of renal cysts has been reported to be associated with aortic aneurysm or dissection by imaging studies, an autopsy study has not been performed. Therefore, in our institute, recent consecutive adult autopsy cases (n = 108, 64 males and 44 females) were reviewed. The circumferences and atherosclerosis ratios of both thoracic and abdominal aorta were individually measured and graded. The number of renal cysts was scored and graded. Age of subjects along with histories of smoking, hypertension, and diabetes mellitus were confirmed. Multiple linear regression analyses demonstrated that severity of atherosclerosis and the number of renal cysts were correlated with thoracic aortic circumference, while only the number of renal cysts was correlated with abdominal aortic circumference (p < 0.05), which was more predominant in female subjects (p < 0.05). Microscopically, significantly more dilated renal tubules (by Student's t-test, p < 0.05) along with decreased stainability of basement membrane by Periodic acid-Schiff staining and immunostaining of type IV collagen were noted in background renal tissues in cases with numerous renal cysts than in age- and sex-matched controls without renal cysts (n = 10 vs. 10). The present study suggests that a syndrome that affects both aorta and renal tubules may exist.     

Trehalose Suppresses Lysosomal Anomalies in Supporting Cells of Oocytes and Maintains Female Fertility

Supporting cells of oocytes, i.e., cumulus cells, control oocyte quality, which determines fertilization success. Therefore, the transformation of mature and immature cumulus cells (MCCs and ICCs, respectively) into dysmature cumulus cells (DCCs) with dead characteristics deteriorates oocyte quality. However, the molecular basis for this transformation remains unclear. Here, we explored the link between autophagic decline and cumulus transformation using cumulus cells from patients with infertility, female mice, and human granulosa cell-derived KGN cell lines. When human cumulus cells were labeled with LysoTracker probes, fluorescence corresponding to lysosomes was enhanced in DCCs compared to that in MCCs and ICCs. Similarly, treatment with the autophagy inhibitor chloroquine elevated LysoTracker fluorescence in both mouse cumulus cells and KGN cells, subsequently suppressing ovulation in female mice. Electron microscopy analysis revealed the proliferation of abnormal lysosomes in chloroquine-treated KGN cells. Conversely, the addition of an autophagy inducer, trehalose, suppressed chloroquine-driven problematic lysosomal anomalies and ameliorated ovulation problems. Our results suggest that autophagy maintains the healthy state of the supporting cells of human oocytes by suppressing the formation of lysosomes. Thus, our results provide insights into the therapeutic effects of trehalose on female fertility.     

Alteration of Annexin IV Expression in Alcoholics

Western blot analysis was performed by using a specific antibody to measure annexin IV in human postmortem brain samples from alcoholic subjects. The analysis showed a significantly augmented expression in the hippocampus compared with controls, whereas the expression in the frontal cortex was equivalent in both groups. Annexin IV expression in the occipital cortex tended to increase in alcoholics. It was shown further that autoantibodies to annexin IV were increased significantly in alcoholic patients compared with controls. Thus, annexin IV may become a novel biological marker for alcoholics.     

Factors Influencing in Vivo Disposition of Polymeric Micelles on Multiple Administrations

l-lactic acid)₃₀ (AB-type), which accumulates in solid tumors through the enhanced permeability and retention (EPR) effect. However, lactosome on multiple administrations changed its pharmacokinetics from accumulation in tumors to liver due to the production of antilactosome IgM, which was triggered by the first administration. This phenomenon is called the accelerated blood clearance (ABC). In order to reduce the production of antilactosome IgM, a novel nanoparticle composed of (poly(sarcosine)₂₃)₃-block-poly(l-lactic acid)₃₀ (A₃B-type) was prepared. The A₃B-type lactosome at the second administration showed an in vivo disposition similar to that at the first administration due to suppression of antibody production. This study involving the AB- and A₃B-type lactosomes, with variation of conditions, revealed that the high local density of poly(sarcosine) chains of the A₃B-type lactosome should relate to the prevention of a polymeric micelle from interacting B-cell receptors.     

Distinct intraspecific variations of garlic (Allium sativum L.) revealed by the exon–intron sequences of the alliinase gene

Garlic (Allium sativum L.) has been used worldwide as a food and for medicinal purposes since early times. Garlic cultivars exhibit considerable morphological diversity despite the fact that they are mostly sterile and are grown only by vegetative propagation of cloves. Considerable recombination occurs in garlic genomes, including the genes involved in secondary metabolites. We examined the genomic DNAs (gDNAs) from garlic, encoding alliinase, a key enzyme involved in organosulfur metabolism in Allium plants. The 1.7-kb gDNA fragments, covering three exons (2, 3, and 4) and all four introns, were amplified from total DNAs prepared from garlic samples produced in Asia and Europe, leading to 73 sequences in total: Japan (JPN), China (CHN), India (IND), Spain (ESP), and France (FRA). The exon sequences were highly conserved among all the sequences, probably reflecting the fully functional alliinase associated with the flavor quality. Distinct intraspecific variations were detected for all four intron sequences, leading to the haplotype classifications. A close relationship between JPN and CHN was observed for all four introns, whereas IND showed a more divergent distribution. ESP and FRA afforded clearly different variants compared with those from Asian sequences. The present study provides information that could be useful in the development of an additional molecular marker for garlic authentication and quality control.     

Cytochrome P450 1A1 (CYP1A1) inhibitor alpha-naphthoflavone interferes with UDP-glucuronosyltransferase (UGT) activity in intact but not in permeabilized hepatic microsomes from 3-methylcholanthrene-treated rats: possible involvement of UGT-P450 interactions

The effects of cytochrome P450 (P450, CYP) ligands and permeabilization of microsomes on 3-hydroxybenzo(a)pyrene [3-OH-B(a)P] glucuronidation mediated by rat hepatic microsomes were studied. While the UDP-glucuronosyltransferase (UGT) activity with non-permeabilized microsomes from 3-methylcholanthrene (MC)-treated rats was markedly reduced by alpha-naphthoflavone (NF), this inhibitor had hardly any effect when permeabilized microsomes were used in which the inhibitor was expected to have easy access to UGT. Kinetic analysis indicated that the inhibitory effect of alpha-NF is competitive. These results suggest that a UGT isoform(s) involved in 3-OH-B(a)P glucuronidation is interfered by a CYP1A inhibitor via a mechanism dependent on the intact nature of microsomal membranes in MC-treated rats. It is likely that P450 functions as a substrate transporter for some isoforms of UGT via possible interactions between UGT and P450.