‘Ischemic tolerance’ phenomenon detected in various brain regions

We investigated the effects of mild and non-lethal ischemic insult on neuronal death following subsequent lethal ischemic stress in various brain regions, using a gerbil model of bilateral cerebral ischemia. Single 10-min ischemia consistently caused neuronal damage in the hippocampal CA1, CA2, CA3 and CA4, layer III/IV of the cerebral cortex, dorsolateral part of the caudoputamen and ventrolateral part of the thalamus. On the other hand, in double ischemia groups, 2-min ischemic insult 2 days before 10-min ischemia exhibited significant protection in the CA1 and CA3 of the hippocampus, the cerebral cortex, the caudoputamen and the thalamus. Five-min ischemic insult 2 days before 10-min ischemia also showed protective effect in the same areas as those of 2-min ischemia except for the CA1 region of the hippocampus, while 1-min ischemic insult exhibited no protective effect in any brain regions. In the immunoblot analysis, both 2- and 5-min ischemia caused increased synthesis of heat shock protein 72 (HSP 72) in the hippocampus, but 1-min ischemia did not. The present study demonstrated that the ‘ischemic tolerance’ phenomenon was widely found in the brain and also suggested that ischemic treatment severe enough to cause HSP 72 synthesis might be needed for induction of ‘ischemic tolerance’.     

Enhancement of hepatitis-B surface-antigen expression by 5-azacytidine in a hepatitis-B-virus-transfected cell line.

The human hepatoblastoma-derived cell line HB611 secretes hepatitis-B surface antigen (HBsAg) and hepatitis-B e antigen (HBeAg) into the medium. Hepatitis-B-virus (HBV) DNA integrated into the cellular genome was found to be hypermethylated. When the cells were treated with 5-azacytidine for 3 days, the level of HBsAg in the medium increased, while the level of HBeAg remained constant. The level of alpha-fetoprotein (AFP) decreased with the 5-azacytidine treatment. Southern blot analysis of DNA digested with HpaII or MspI showed that 5-azacytidine treatment resulted in hypomethylation of the integrated HBV DNA, suggesting that 5-azacytidine increased HBsAg production in the cells through hypomethylation of the HBV genomic DNA.     

INTRAOPERATIVE BLEEDING IN ENDOSCOPIC SUBMUCOSAL DISSECTION IN THE STOMACH AND STRATEGY FOR PREVENTION AND TREATMENT

To control intraoperative bleeding is an important key to successful endoscopic submucosal dissection. The distribution of submucosal vessels encountered during the procedure differ in places in the stomach and are roughly categorized into three groups: those located in the antrum, those in the lesser curvature, and those on the anteroposterior corpus wall which consists of oblique muscle layers. Therefore, knowledge of a suitable setting of diathermy and adjusted depth of dissection in the submucosal layer for each site is imperative. The combination of utilizing the distal attachment forced or swift coagulation (trimming with coagulation mode) have enable the treatment with an insulation tipped knife safer.     

Effect of tacrolimus and partial hepatectomy on transthyretin metabolism in rats

Liver transplantation, which serves as treatment of familial amyloidotic polyneuropathy (FAP), and domino liver transplantation, which utilizes resected livers from patients with FAP for treatment of liver diseases, may induce changes in transthyretin (TTR), a pathogenic FAP-related protein. To evaluate this possibility, we performed a 70% hepatectomy or administered tacrolimus to Dark Agouti (DA) rats for 7 days and then measured changes in liver TTR mRNA levels and changes in serum TTR concentrations. After hepatectomy, TTR mRNA levels decreased by 77%; at day 3, they returned to preoperative levels. Except for slightly elevated serum TTR concentrations 12 h after operation, serum TTR levels remained unchanged. Thus, partial hepatectomy did not influence serum TTR concentrations. After tacrolimus administration, TTR mRNA declined by 56% 12 h after the experiment started; however, after day 3, a rebound phenomenon occurred until day 7. Tacrolimus may facilitate serum TTR degradation, although production of TTR in the liver also increased. This finding -- that TTR, the source of FAP-inducing amyloid, did not increase after transplantation -- may help post-transplantation treatment of patients who have FAP and other liver diseases.     

Congestive heart failure in elderly readmitted patients]

The clinical features of congestive heart failure in the elderly were investigated in 104 patients (57 males, 47 females, mean age of 79.2). Patients were divided into two subgroups, the readmission group, 33 patients who were readmitted within 6 months after discharge, and the non-readmission group. Chief complaints were dyspnea, edema, chest pain, loss of appetite, chest compression, and palpitation. Heart failure was caused by infection, myocardial ischemia, arrhythmia, inappropriate drug usage including poor drug compliance, the use of beta-blockers, excessive intake of sodium, and anemia. Careful use of drug was essential especially in the readmission group. Major underlying heart disease were ischemic heart disease (39.4%), valvular disease (26.9%), hypertensive heart disease (9.6%), with cardiomyopathy, congenital heart disease seen in the minority. There was no statistically significant difference in underlying heart diseases between the two groups. Supraventricular arrhythmias such as atrial fibrillations, paroxysmal atrial fibrillations, paroxysmal supraventricular tachycardias, and premature atrial contractions were noted in 85.3% of the cases. Drugs for treatment were diuretics, digitalis, isosorbide dinitrate, calcium antagonists. ACE inhibitors and alpha-blockers were also used, showing that vasodilators were more extensively used than before. The major complications were hypertension (39.4%), renal dysfunction (27.9%), cerebrovascular disease (26.9%), diabetes mellitus (16.5%), arteriosclerosis obliterans (7.7%). Renal dysfunction, arteriosclerosis obliterans was seen significantly more frequently in the readmission group. The prognosis at one year after admission was significantly worse in the readmission group. In summary, the major underlying diseases were ischemic heart disease, valvular disease, and hypertensive heart disease. Ischemic heart disease was seen more frequently than in previous investigations at our hospital.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pathological effects on mice by gambierol, possibly one of the ciguatera toxins

Gambierol was isolated from Gambierdiscus toxicus, which causes ciguatera fish poisoning. The acute toxicological effects induced in mice by synthesized gambierol were studied. The lethal doses were about 80 μg/kg by i.p. and i.v., and 150 μg/kg by p.o. The main injury by this toxin was observed in the lung, and secondary in the heart, resulting in systemic congestion. Another toxic effect was seen in the stomach, inducing hypersecretion and ulceration. With survival from the severe stage during the initial 3 h, recovery was favorable, especially after 4 days. Additional effects were not evident during 1-week post-administration observation.     

Independent association of antibodies against human papillomavirus type 16 and E7 proteins with cervical cancer

The E4 open reading frame (ORF) of human papillomaviruses (HPVs) is transcribed in abundant mRNAs encoding an fusion gene during the productive infection, and the HPV 16 E7 ORF encodes an oncoprotein detectable in the cell lines derived from cervical carcinoma. We examined 421 human sera, which included 108 samples from the patients with cervical carcinoma, for the presence of IgG antibodies against the HPV 16 E4 and E7 proteins by enzyme-linked immunosorbent assay. Bacterially expressed fusion protein lac- and nonfusion protein E7 were purified and used as antigens. All of the 22 serum samples positive for anti-E7 antibody and the 11 out of 15 samples positive for anti- antibody were from the patients with cervical carcinoma, but only one sample was found to contain both anti- and anti-E7 antibodies. These findings show specific and independent association of these antibodies with cervical carcinoma.