Hepatitis B virus RNA is measurable in serum and can be a new marker for monitoring lamivudine therapy

BACKGROUND

Changes in the serum hepatitis B virus (HBV) RNA level during lamivudine therapy were compared to those in the serum HBV DNA and HBV core-related antigen (HBVcrAg) levels in 24 patients with chronic hepatitis B.

METHODS

For measurement of HBV RNA, total nucleic acid was extracted from serum samples and treated with RNase-free DNase I. After cDNA synthesis from extracted RNA, HBV RNA was measured by real-time detection polymerase chain reaction.

RESULTS

The peak fraction of HBV RNA in serum samples was consistent with peak fractions of HBV DNA and HBV core protein in a sucrose gradient analysis, indicating that HBV RNA was incorporated into virus particles. All levels of HBV DNA, HBV RNA, and HBVcrAg decreased gradually during lamivudine therapy (P < 0.001 for all). The amount of decrease from the start of lamivudine therapy was significantly higher for HBV DNA than for HBV RNA or HBVcrAg during 6 months of lamivudine therapy (P < 0.001 for all). However, a similar difference was not seen between HBV RNA and HBVcrAg levels during that period. The HBV RNA level was significantly correlated (P < 0.001 for all) with levels of HBV DNA and HBVcrAg both at the beginning and 2 months after the start of lamivudine therapy.

CONCLUSIONS

HBV RNA is detectable in serum in a form indicating incorporation into virus particles, and its serum level might serve as a new viral marker with a significance different from that of HBV DNA in lamivudine therapy.

16q-linked autosomal dominant cerebellar ataxia: a clinical and genetic study

The autosomal dominant cerebellar ataxias (ADCAs) comprise a genetically and clinically heterogenous group of neurodegenerative disorders. Very recently, a C-to-T single nucleotide substitution in the puratrophin-1 gene was found to be strongly associated with a form of ADCA linked to chromosome 16q22.1 (16q-linked ADCA; OMIM 600223). We found the C-to-T substitution in the puratrophin-1 gene in 20 patients with ataxia (16 heterozygotes and four homozygotes) and four asymptomatic carriers in 9 of 24 families with an unknown type of ADCA. We also found two cases with 16q-linked ADCA among 43 sporadic patients with late-onset cortical cerebellar atrophy (LCCA). The mean age at onset in the 22 patients was 61.8 years, and that of homozygous patients was lower than that of heterozygous ones in one family. Neurological examination revealed that the majority of our patients showed exaggerated deep tendon reflexes in addition to the cardinal symptom of cerebellar ataxia (100%), and 37.5% of them had sensorineural hearing impairment, whereas sensory axonal neuropathy was absent. The frequency of 16q-linked ADCA was about 1/10 of our series of 110 ADCA families, making it the third most frequent ADCA in Japan.

Lysocellin, a metabolite of the novel drug 'alopestatin', induces G1 arrest and prevents cytotoxicity induced by etoposide

We report here that lysocellin, a polyether antibiotic from a streptomycete, induces G1 phase arrest in human osteosarcoma MG63 cells. Lysocellin up-regulates p21WAF1/Cip1 and down-regulates cyclin D1 at the mRNA level. In addition, cyclin D1 is down-regulated by the proteasome-dependent signal pathway in MG63 cells. In drug combination studies, we found that lysocellin treatment weakened the cytotoxic activity of etoposide in MG63 cells using a colony-formation assay. To study the in vivo efficacy of lysocellin, we isolated a novel compound related to lysocellin from the same streptomycete, and found that the novel drug is converted to lysocellin in vivo and decreases etoposide-induced alopecia in a neonatal rat model. We raise the possibility that this novel drug, named 'alopestatin', may be a promising agent against alopecia.

Laparoscopic findings in patients with nonalcoholic steatohepatitis

BACKGROUND/AIMS

Laparoscopic observation of the liver is important to diagnose liver conditions accurately. However, the laparoscopic findings of nonalcoholic steatohepatitis (NASH) have not been characterized. The aim of this study was to clarify the laparoscopic characteristics of NASH.

METHODS

Twenty-four patients were enrolled. The degrees of hepatomegaly, color and irregularity of the liver surface, and the presence of depressions, patches, and vesicles were investigated. These laparoscopic findings were compared among NASH, alcoholic liver disease (ALD), and autoimmune hepatitis (AIH).

RESULTS

Mild hepatomegaly, dullness of the liver edge, increased fat accumulation of the round ligament, and whitish markings were found in most of the patients with NASH. Small depressions were observed in approximately 70% of the patients. As fibrosis developed, the liver surface became whiter and more uneven. Compared with patients with ALD and AIH, increased fat accumulation of the round ligament and dullness of the liver edge were observed more frequently in those with NASH. However, coarse and groove-like depressions were rare in NASH patients.

CONCLUSIONS

Several findings, including mild hepatomegaly, increased fat accumulation of the round ligament, rounded liver edge, whitish markings, and small depressions were common in patients with NASH. However, coarse and groove-like depressions were rare. These findings may be helpful for confirming a diagnosis of NASH.

Severe alcoholic hepatitis with extremely high neutrophil count successfully treated by granulocytapheresis

We report a severe alcoholic hepatitis (SAH) patient with an extremely high WBC count, high serum bilirubin and low prothrombin time (PT) successfully treated with granulocytapheresis. After neutrophil-elastase inhibitor failed to reduce WBC count, methylprednisolone pulse therapy was performed. However, WBC count continued to be elevated to 97,190/microl (neutrophils 97.0%) despite improvement of total bilirubin and PT. After 5 sessions of granulocytapheresis and ulinastatin administration, increased serum IL-6, IL-8, neutrophil-elastase and WBC count gradually decreased. We could conclude that granulocytapheresis and ulinastatin can be very effective in reducing cytokines and neutrophil-elastase, and in improving the general status of SAH patients.

Autoimmune pancreatitis and complement activation system

OBJECTIVES

Autoimmune pancreatitis is characterized by increased serum level of IgG4, but its pathogenesis has not been fully elucidated. Because this disease is occasionally associated with decreased levels of complements, we sought to clarify which complement activation system was operating in its active state.

METHODS

We measured serum levels of complements, mannose-binding lectin, and circulating immune complex in patients with autoimmune pancreatitis, patients with chronic pancreatitis, and healthy controls.

RESULTS

We found high serum circulating immune complex values, which decreased significantly after corticosteroid therapy. In patients with autoimmune pancreatitis, elevated levels of circulating immune complex, as determined by C1q assay, were significantly associated with increased serum levels of IgG1 and decreased levels of C4, as well as with a tendency toward decreased levels of C3. There were no significant differences in the serum levels of mannose-binding lectin or in the frequency of a mutant allele of mannose-binding lectin between patients with autoimmune pancreatitis and those with chronic calcifying pancreatitis. Furthermore, corticosteroid therapy had no effect on the level of mannose-binding lectin.

CONCLUSIONS

Autoimmune pancreatitis exhibits a high serum circulating immune complex values in its active state, which links to a complement activation system with a classic pathway rather than the mannose-binding lectin pathway or alternative pathways.

CT virtual pancreatoscopy: a new method for diagnosing intraductal papillary mucinous neoplasm (IPMN) of the pancreas

BACKGROUND

We sought to validate computed tomographic virtual pancreatoscopy (CT-VP) created by multidetector row CT (MD-CT) in the clinical diagnosis of intraductal papillary mucinous neoplasm (IPMN) of the pancreas.

METHODS

Five cases of pancreatic IPMNs were included in this study. A nasopancreatic drainage tube was inserted and the pancreatic duct was filled with contrast medium, after which an upper abdominal scan was performed by MD-CT. CT-VP and three-dimensional (3D) CT pancreatographic images were created using a workstation and compared with images by conventional diagnostic techniques. All cases were evaluated by endoscopic retrograde pancreatography (ERP) and three cases of main duct type were assessed by intraoperative real pancreatoscopy (RP).

RESULTS

In the main duct cases, papillary projections in the main pancreatic duct and branch orifices were clearly detected by CT-VP. These lesions and structures were confirmed by intraoperative RP, and the CT-VP images were clearer than RP images. In branch cases, a surface-rendering method allowed protruding lesions to be clearly detected in the dilated branches.

CONCLUSION

Compared with conventional ERP or RP, CT-VP and 3D-CT pancreatographic images were finer in quality, and the procedures were less invasive, faster, and less expensive. The potential shown by CT-VP with 3D-CT pancreatography in the clinical diagnosis of pancreatic IPMNs suggests that this approach may replace ERP in the near future.

Assessment of KL-6 as a tumor marker in patients with hepatocellular carcinoma

AIM: To investigate the clinical significance of KL-6 as a tumor marker of HCC in two different ethnic groups with chronic liver disease consecutively encountered at outpatient clinics.

METHODS: Serum KL-6 was measured by the sandwich enzyme immunoassay method using the KL-6 antibody (Ab) as both the capture and tracer Ab according to the manufacturer’s instructions (Eisai, Tokyo, Japan). Assessment of alpha fetoprotein (AFP) and protein induced vitamin K deficiency or absence (PIVKA-II) was performed in both groups using commercially available kits.

RESULTS: A significantly higher mean serum KL-6 (556±467 U/L) was found in HCC in comparison with non-HCC groups either with (391±176 U/L; P<0.001) or without (361±161 U/L; P<0.001) liver cirrhosis (LC). Serum KL-6 level did not correlate with either AFP or PIVKA-II serU/Levels. Using receiver operating curve analysis for KL-6 as a predictor for HCC showed that the area under the curve was 0.574 (95%CI = 0.50-0.64) and the KL-6 level that gave the best sensitivity (61%) was found to be 334 U/L but according to the manufacturer’s instructions; a cut-off point of 500 U/L was used that showed the highest specificity (80%) in comparison with AFP and PIVKA-II (78% vs 72% respectively). Combining the values of the three markers improved specificity of AFP for HCC diagnosis from 78% for AFP alone; 93% for AFP plus PIVKA-II to 99% for both plus KL-6 value (P<0.001). Mean serum alkaline phosphatase level was significantly higher in KL-6 positive (564±475) in comparison with KL-6 negative (505±469) HCC patients (P = 0.021), but such a difference was not found among non-HCC corresponding groups.

CONCLUSION: KL-6 is suggested as a tumor for HCC. Its positivity may reflect HCC-associated cholestasis and/or local tumor invasion.

Inhibitory effect of 22-oxa-1,25-dihydroxyvitamin D3, maxacalcitol, on the proliferation of pancreatic cancer cell lines

Effective chemotherapy for pancreatic cancer is urgently needed. The aim of this study was to compare the anti-proliferative activity on pancreatic cancer cell lines of the vitamin D(3) analog, 22-oxa-1,25-dihydroxyvitamin D(3), maxacalcitol, with that of 1,25-dihydroxyvitamin D(3), calcitriol, with analysis of vitamin D receptor status and the G(1)-phase cell cycle-regulating factors. Antiproliferative effects of both agents were compared using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method and by measuring the tumor size of xenografts inoculated into athymic mice. Scatchard analysis of vitamin D receptor contents, and mutational analysis of receptor complementary DNA were performed. Levels of expression of cyclins, cyclin-dependent kinases and cyclin-dependent kinase inhibitors, p21 and p27, were analysed by western blotting. In vitro, maxacalcitol and calcitriol markedly inhibited the proliferation and caused a G(1) phase cell cycle arrest with the appearance of numerous domes. In vivo, maxacalcitol inhibited the growth of BxPC-3 xenografts more significantly than calcitriol, without inducing hypercalcemia. Responsive cells had abundant functional vitamin D receptors. However, Hs 766T, showing no response to either agent, had the second highest receptor contents with no abnormalities in its primary structure deduced by receptor complementary DNA. In the responsive cells, p21 and p27 were markedly up-regulated after 24h of treatment with both agents. In non-responsive cells, no such changes were observed. In conclusion, maxacalcitol and calcitriol up-regulate p21 and p27 as an early event, which in turn could block the G(1)/S transition and induce growth inhibition in responsive cells, and maxacalcitol may provide a more useful tool for the chemotherapy of pancreatic cancer than calcitriol because of its low toxicity.

Age-specific antibody to hepatitis E virus has remained constant during the past 20 years in Japan

We investigated the presence of antibodies to hepatitis E virus (anti-HEV) and hepatitis A virus (anti-HAV) by enzyme immunoassays in sera from 1015 individuals collected in 1974, 1984 and 1994. Age-specific profiles of anti-HEV remained unchanged with a peak at 40-49 years, while those of anti-HAV started to increase in individuals aged 20-29 years in 1974, 30-39 years in 1984 and 40-49 years in 1994. These results suggest that a silent HEV infection has been taking place in the last 20 years or so in Japan, while HAV infection has been terminated at least since 1974.

High prevalence of hypothyroidism in patients with autoimmune pancreatitis

Autoimmune pancreatitis is a unique form of chronic pancreatitis and has been correlated with various extrapancreatic lesions. To search for a correlation between autoimmune pancreatitis and thyroid lesions, we measured thyroid functions in 41 patients with autoimmune pancreatitis and in 41 patients with chronic calcifying pancreatitis and investigated the correlation between HLA antigens and hypothyroidism. We found a significant difference in the prevalence of antithyroglobulin antibody and hypothyroidism between patients with autoimmune pancreatitis and those with chronic pancreatitis (34.1 vs. 7.3%, P = 0.005, and 26.8 vs. 0%, P = 0.0005, respectively). Patients with hypothyroidism had a significantly higher frequency of antithyroglobulin antibody (63.6%) than those without hypothyroidism but showed no differences in other findings, including serum IgG4 concentration. We could find no significant association between any HLA antigens and the hypothyroid state of autoimmune pancreatitis. One quarter of the patients with autoimmune pancreatitis have hypothyroidism that may be independent of the active state of the pancreatic lesion or systemic fibrosing disorder, and thus patients suspected of having autoimmune pancreatitis should be evaluated for possible hypothyroidism.

Genetic analysis of the HLA region of Japanese patients with type 1 autoimmune hepatitis

BACKGROUND/AIMS

Genetic predisposition to type 1 autoimmune hepatitis (AIH) is linked mainly to HLA-class II genes. The aim of this study is to scan the HLA region for additional genes which may contribute to type 1 AIH susceptibility.

METHODS

We performed association analysis using HLA class I and II alleles and 18 polymorphic microsatellite markers distributed throughout the HLA region. We specifically assessed tumor necrosis factor (TNF)-alpha gene polymorphisms.

RESULTS

The frequencies of HLA-DRB1*0405, DRB4 and DQB1*0401 alleles were significantly higher in AIH patients. The association study revealed the presence of three segments in the HLA region showing significantly low P (Pc) values. The first segment was located around the HLA-DR/-DQ subregion, the second was around the HLA-B54 allele, and the third was around two microsatellites near the TNF gene cluster. However, stratification analysis for the effect of DRB1*0405 eliminated association of the latter two segments. Haplotype D of the TNF-alpha promoter gene polymorphisms was weakly associated with susceptibility, but was found to be not significant after stratification analysis.

CONCLUSIONS

The most influential gene on type 1 AIH pathogenesis in Japanese is the HLA-DRB1. Other genes in the HLA region, including TNF-alpha, have little or no association with type 1 AIH susceptibility.

Factors related to home discharge of cerebrovascular disease patients: 1-year follow-up interview survey of caregivers of hospitalized patients in 53 acute care hospitals in Japan

In Japan, many disabled elderly people remain hospitalized for long periods. Cerebrovascular diseases (CVD) are the most causes responsible for such disability. To examine the predictors of home discharge in CVD patients, we performed a 1-year follow-up interview of the main caregivers of patients hospitalized with a CVD event. The initial cohort consisted of CVD patients hospitalized in all the second level emergency and general hospitals in Ibaraki Prefecture in February 1992 (N=888 patients in 53 hospitals). In the following year, we performed an interview survey of the main caregivers of these CVD patients. The survey items included the characteristics of the patients (including medical and socioeconomic conditions), caregivers, and family members. The final study population included the main caregivers of 187 home patients and 90 institutionalized patients. We compared these two groups in terms of predictors of discharge to home. The results of multiple logistic regression analysis showed that the following seven factors were related to home discharge; better baseline activities of daily living (ADL), larger improvement in ADL, larger family size, spouse as the caregiver, caregiver without a full-time job, better economic status of the caregiver, and sources of the patient's income. Our study indicated that the caregiver's conditions were closely related to home discharge of the CVD patients. More attention should, therefore, be centered on the caregiver's well-being and economic aspects as well as the patient's conditions in order to encourage home discharge of stroke patients.

Patients with and without loss of hepatitis B virus DNA after hepatitis B e antigen seroconversion have different virological characteristics

The characteristic differences between patients with and without loss of hepatitis B virus (HBV) DNA after achieving hepatitis B e antigen seroconversion were analyzed by comparing changes in HBV DNA and HBV core-related antigen levels during a period from 3 years before to 3 years after the seroconversion. Of the 24 seroconverters, 6 (inactive replication group) showed continuous loss of HBV DNA in serum after the seroconversion and the remaining 18 did not lose HBV DNA (active replication group). The HBV DNA level was similar between the two groups, while the HBV core-related antigen level was significantly lower in the active replication group than in the inactive replication group before the seroconversion. The levels of both HBV DNA and HBV core-related antigen decreased remarkably around the time of seroconversion in the inactive replication group, while these levels did not change or decreased slightly in the active replication group. After the seroconversion, the HBV DNA level was significantly higher in the active replication group than in the inactive replication group, while the HBV core-related antigen level was similarly low between the two groups. Because the serum level of HBV core-related antigen mainly reflects that of HBe antigen, the low level of HBV core-related antigen seen after seroconversion in both groups might have contributed to the occurrence of seroconversion. The precore and core promoter mutations which cause diminished excretion of hepatitis B e antigen were significantly more frequent in the active replication group than in the inactive replication group. It was therefore considered that the seroconversion was caused mainly by a decrease in viral replication in the inactive replication group, and mainly by a decrease in HBe antigen production in the active replication group.

Nucleotide mutations associated with hepatitis B e antigen negativity

One hundred and forty four patients with chronic hepatitis B were tested to identify new mutations associated with hepatitis B e antigen (HBeAg) negativity, using a full genome sequence analysis. All the patients were Chinese and had hepatitis B virus infection of genotype C. Patients with none of the pre-core or core promoter mutations were significantly (P < 0.001) less common in the group with anti-HBe (13%) than in the group with HBeAg (56%). The complete nucleotide sequence was determined in four anti-HBe-positive patients who had neither pre-core nor core promoter mutations and in five HBeAg-positive patients who also had neither of these mutations (the groups were matched for age and sex). Six mutations were found to be significantly more common in the former group than in the latter: G529A (3/4 vs. 0/5), C934A (4/4 vs. 1/5), A1053G (4/4 vs. 1/5), G1915T/A (4/4 vs. 0/5), T2005C/A (4/4 vs. 0/5), and C3026T (3/4 vs. 0/5). Three of the six mutations were significantly more common in the four anti-HBe-positive patients who had neither pre-core nor core promoter mutations, compared to 11 HBeAg-positive patients who had pre-core and core promoter mutations, and also compared to 15 anti-HBe-positive patients who had pre-core and core promoter mutations, suggesting further the specificity of these mutations. Of the six mutations, two resulted in amino acid substitution in the polymerase protein, and one is located near the enhancer I region. The results suggest that the six newly discovered mutations are associated with HBeAg negativity.

Fine mapping of the muscular dystrophy (AM) gene on chicken chromosome 2q

Our previous studies revealed that the genetic locus for chicken muscular dystrophy of abnormal muscle (AM) mapped to chromosome 2q, and that the region showed conserved synteny with human chromosome 8q11-24.3. In the current study, we mapped the chicken orthologues of genes from human chromosome 8q11-24 in order to identify the responsible gene. Polymorphisms in the chicken orthologues were identified in the parents of the resource family. Twenty-three genes and expressed sequence tags (ESTs) were mapped to chicken chromosome 2 by linkage analysis. The detailed comparative map shows a high conservation of synteny between chicken chromosome 2q and human chromosome 8q. The AM locus was mapped between [inositol(myo)-1(or4)-monophosphatase 1] (IMPA1) gene and [core-binding factor, runt domain, alpha-subunit 2; translocated to 1; cyclin D-related] (CBFA2T1) gene. The genes located between IMPA1 and CBFA2T1 are the most likely candidates for chicken muscular dystrophy.

Hepatocellular carcinoma: recent trends in Japan

During the past 20 years, primary liver cancer, 95% of which is hepatocellular carcinoma (HCC), has ranked third in men and fifth in women as a cause of death from malignant neoplasm in Japan. The numbers of deaths and death rate from HCC showed a sharp increase beginning in 1975. Although both hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are important causes, HCV-related HCC has accounted for most of the recent increase and now represents 75% of all HCC in Japan. Geographically, HCC is more frequent in western than eastern Japan, and the death rate of HCC in each prefecture correlates with prevalence of anti-HCV. Among patients with HCV-related HCC, a history of blood transfusion was a relatively important source of infection in the 1990s, whereas community-acquired infections increased after 2000. There was a negative correlation between the duration from onset of infection to development of HCC and the age at onset. Interferon therapy for chronic hepatitis C has reduced the risk for HCC, indicating that early detection of HCV carriers and better treatment will contribute to improved outcomes. Nationwide screening for HCV and HBV began in 2002 in Japan, and reduction of HCC is anticipated. Further research should focus on mechanisms of carcinogenesis by HCV and HBV, development of more effective treatments, and establishment of early detection and treatment approaches. Better understanding of HCC unrelated to HCV and HBV and possibly because of steatohepatitis and diabetes should also be a major concern in future studies.

Types of human leukocyte antigen and decrease in HCV core antigen in serum for predicting efficacy of interferon-Alpha in patients with chronic hepatitis C: analysis by a prospective study

BACKGROUND

A prospective study was conducted to evaluate the influence of host factors, including human leukocyte antigen (HLA), and viral factors, including hepatitis C virus (HCV) core antigen, on the response to interferon (IFN)-Alpha.

METHODS

Natural IFN-Alpha was given to 66 patients with chronic hepatitis C at a dose of 9 million units per day for 2 weeks, followed by 9 million units three times a week for 22 weeks.

RESULTS

Sustained virological response without detectable HCV RNA in serum 24 weeks after the end of IFN therapy was achieved in 21 patients, while it was not in 32 patients; the remaining 13 patients were not evaluated. HCV core antigen and HCV RNA started to decrease 1 and 4 weeks, respectively, after the commencement of IFN in responders ( P = 0.02 and P = 0.05, respectively). On univariate analysis, age of 50 years or less ( P < 0.001); lack of HLA DR6 ( P = 0.018) or DR52 ( P < 0.041); platelets more than 14 x 10(4)/mm(3) ( P = 0.031); HCV core antigen 500 fmol/l or less ( P = 0.001); and HCV RNA 100 KIU/ml or less were predictive of response. On multivariate analysis, age 50 years or less (odds ratio [OR], 4.009; P = 0.039); lack of HLA DR6 (OR, 8.130; P = 0.027); IFN-naive (OR, 11.63; P = 0.016); HCV core antigen 500 fmol/l or less (OR, 10.61; P = 0.007); and genotypes other than 1b (OR, 8.929; P = 0.010) were predictive of response.

CONCLUSIONS

Lack of HLA DR6 determined the response to IFN. HCV core antigen was useful in predicting and monitoring the response to IFN.

Hepatic hydrothorax in the absence of ascites diagnosed by intraperitoneal spraying of indocyanine green

Hepatic hydrothorax in the absence of ascites is a rare complication of liver cirrhosis. A 56-year-old woman was referred to our hospital because of a massive pleural effusion on the right side, requiring continuous drainage. Although the patient was known to have chronic hepatitis C, she had no signs of hepatic failure including ascites. A laparoscopic examination revealed a nodular liver and a small volume of ascites in the peritoneal cavity. Indocyanine green sprayed into the intraperitoneal cavity was excreted from the pleural drain just after the spraying, indicating an intraperitoneal origin of the pleural fluid. Discontinuation of pleural drainage and an introduction of standard treatment for ascites due to liver cirrhosis (including restriction of salt intake and diuretic administration) resulted in a marked decrease of pleural effusion.

Ectoparasites of the Pallas squirrel, Callosciurus erythraeus, introduced to Japan

The squirrel Callosciurus erythraeus (Pallas) (Rodentia: Sciuridae) was intentionally introduced to Japan in 1935 and has become established throughout much of the country. Although they live mainly in forests, Pallas squirrels come into gardens and are frequently fed by people or kept as pets, so their ectoparasites could be of potential medical as well as veterinary importance. During 2001-2003 we conducted the first ectoparasite survey of Pallas squirrels in Japan. From 105 C. erythraeus captured in Kamakura District of Kanagawa Prefecture on Honshu Island, three types of ectoparasite were found: 52 specimens of the sucking louse Neohaematopinus callosciuri Johnson (Anoplura: Haematopinidae), 26 fleas Ceratophyllus (Monopsyllus) anisus Rothschild (Siphonaptera: Ceratophyllidae) and four nymphs of the tick Haemaphysalis flava Neumann (Acari: Ixodidae) on 22, 13 and one squirrels, respectively. Evidently in Japan C. erythraeus carries relatively few ectoparasite species; this may be a contributory factor to their invasive success. Further investigations are needed to assess risks of zoonotic transmission of plague or murine typhus by C. anisus, of louse-borne typhus by N. callosciuri and of tularaemia and especially Japanese spotted fever (Rickettsia japonica) by H. flava.

Association between catechol-O-methyltransferase gene polymorphisms and wearing-off and dyskinesia in Parkinson's disease

Catechol-O-methyltransferase (COMT) is an enzyme that inactivates catecholamines, including levodopa. An amino acid change (Val-108-Met) in the COMT protein has been found to result in a change from high to low enzyme activity. In the present study, we genotyped 121 Japanese patients with Parkinson's disease (PD) and 100 controls. Comparison of the allele frequencies revealed that homozygosity for the low-activity allele was significantly more common among PD patients than the controls (p = 0.047, odds ratio = 3.23). In addition, homozygosity for the low-activity allele was overrepresented in PD patients that exhibited the 'wearing-off' phenomenon (p = 0.045, odds ratio = 3.82) or dyskinesia (p = 0.030, odds ratio = 4.80) compared with controls, although these differences were not significant after Bonferroni's correction. Our results may help understand the mechanism that cause complications of levodopa therapy in PD patients.

Comparison of pioglitazone and metformin efficacy using homeostasis model assessment

AIMS

To compare clinical efficacy of two different insulin sensitizers, pioglitazone and metformin, and to reveal factors that influence the clinical efficacy.

METHODS

Seventy-eight Japanese subjects with Type 2 diabetes mellitus poorly controlled with sulphonylureas [38 men and 40 women, aged 57 +/- 9 years, body mass index 25.2 +/- 1.4 kg/m2, and HbA1c 8.3 +/- 0.6% (means +/- SD)] were randomly assigned to groups for the addition of either pioglitazone or metformin and followed up for 4 months. A decrease in HbA1c levels was compared with baseline factors including homeostasis model assessment of insulin sensitivity (HOMA-R) and beta-cell function (HOMA-beta) with 71 subjects who completed the study.

RESULTS

The overall decrease in HbA1c levels was similar for the pioglitazone (-1.2 +/- 0.2%) and metformin (-1.3 +/- 0.1%) groups. In the pioglitazone group, the decrease in HbA1c levels was negatively correlated with baseline HOMA-R (r=-0.698, P<0.0001) and HOMA-beta (r=-0.680, P<0.0001). In contrast, the decrease was positively correlated with baseline HOMA-beta (r=0.556, P=0.0004) in the metformin group. Multivariate analysis revealed that either HOMA-R or HOMA-beta was a main determinant of the decrease in HbA1c levels in the pioglitazone group. In the metformin group, baseline levels of fasting glucose were also included as an independent determinant in addition to HOMA-beta. The subjects with greater HOMA-R (> or =4.0) or HOMA-beta (> or =40%) displayed better response to pioglitazone than to metformin, and vice versa.

CONCLUSIONS

In Type 2 diabetic subjects poorly controlled with sulphonylureas, addition of pioglitazone or metformin resulted in a comparable reduction in HbA1c levels. Subjects with greater insulin resistance or preserved beta-cell function displayed better response to pioglitazone, whereas subjects with reduced beta-cell function displayed better response to metformin.

Factors predisposing to the occurrence of cryoglobulinemia in two cohorts of Egyptian and Japanese patients with chronic hepatitis C infection: ethnic and genotypic influence

The association between cryoglobulinemia and hepatitis C virus (HCV) infection has been reported. However, the factors underlying its wide variation of occurrence have not yet been well identified. To investigate this, cryoglobulinemia was studied in four cohorts of Egyptian and Japanese patients. Fifty Egyptian patients with chronic hepatitis C, infected with genotype 4 (the predominant HCV genotype in Egypt), were compared with 50 age- and sex-matched Japanese patients, infected with HCV genotype 1b (the predominant HCV genotype in Japan). Thirty-two Egyptian and 30 age- and sex-matched Japanese patients with chronic hepatitis B were included as controls. All patients were noncirrhotic. Antinuclear antibody (ANA), immunoglobulins (Ig), and cryoglubulins were assessed. Results showed a significantly higher prevalence of cryoglobulinemia in chronic hepatitis C Japanese genotype 1b (40%) as compared with Egyptian genotype 4 (14%), P = 0.003, while no difference was found between Japanese (17%) and Egyptian chronic hepatitis B controls (13%). Symptomatic cryoglobulinemia was more prevalent in the Japanese than in the Egyptian chronic hepatitis C group (10% vs. 4%), but the difference was not statistically significant. Univariate analysis showed no association between cryoglobulinemia and either age, sex, alanine aminotransferase level, or HCV viral load in Japanese or Egyptian patients, while the mean IgM level was significantly higher in the cryoglobulin-positive than in the cryoglobulin-negative chronic hepatitis C patients in each group (P = 0.003 and 0.017, respectively). Cryoglobulinemia was found to be significantly associated with both high IgG level (P = 0.020), and positive ANA (P < 0.001) in Japanese patients with chronic hepatitis C, genotype 1b but not in Egyptians with genotype 4. Multivariate analysis showed that the only factors predisposing to cryoglobulinemia were Japanese ethnicity with HCV genotype1b (P = 0.002, OR = 2.56), high IgM level of >245 mg/dl (P = 0.018, OR = 2.05) and female gender (P = 0.040, OR = 1/0.66). In conclusion, cryoglobulinemia is prevalent in Japanese patients with chronic hepatitis C infected with genotype 1b, but cryoglobulinemia is not common in Egyptians with HCV genotype 4. Although it was not possible to evaluate ethnicity and HCV genotype separately in this study, HCV genotype 1b appears to predispose more to cryoglobulinemia than does genotype 4. Female gender and high serum IgM level were also related.

A case-control study for early prediction of hepatitis B e antigen seroconversion by hepatitis B virus DNA levels and mutations in the precore region and core promoter

Factors influencing and predictive of seroconversion from hepatitis B e antigen (HBeAg) to antibody (anti-HBe) were sought in a case-control study of 61 patients with chronic hepatitis B who had been observed from 5 years before to 1 year after seroconversion, and 32 patients who did not seroconvert during the entire 6-year period. Almost all of the patients (96%) were infected with HBV genotype C. HBV DNA levels began to decrease 3 years before seroconversion in the seroconverters, while they remained high in the non-converters. The frequency of precore mutation and the loss of HBeAg (A1896) started to increase 1 year before in the converters, and became significantly higher at seroconversion (23 vs. 3%, P = 0.030) than that in the non-converters. Double mutation in the core promoter (T1762/A1764) was more common in the seroconverters than in the non-converters 5 years before seroconversion (48 vs. 28%), and became significantly more frequent at seroconversion (65 vs. 41%, P = 0.046). Seroconversion occurred in 75% of the patients with at least HBV DNA levels <5.5 logarithmic equivalents/mL; precore mutation in 20% or more of HBV DNA; or core promoter mutation. Seroconversion occurred in 50% of those patients within 1 year, 88% within 2 years, and 93% within 5 years. These results indicate that a decrease in HBV DNA levels and mutations in the precore region and the core promoter were associated significantly and complementarily with seroconversion, and each of them or a combination thereof was predictive of seroconversion years ahead.

Expansion of clonotype-restricted HLA-identical maternal CD4+ T cells in a patient with severe combined immunodeficiency and a homozygous mutation in the Artemis gene

We have observed a male infant with severe combined immunodeficiency (SCID) responsible for Artemis gene mutation, in whom marked expansion of the transplacentally grafted maternal CD4(+) T cells was observed in various tissues. His class I and II major histocompatibility antigens (MHC) were identical to his mother's. We analyzed the T-cell populations within target tissues at a molecular level in order to determine whether different T-cell clonotypes are expanded in different types of tissue. Prior to T-cell expansion, the T-cell receptor variable beta (TCRBV) 5.1 subfamily predominated in peripheral blood (PB) lymphocytes. Third complementarity determining region (CDR3) size spectratyping and amino acid sequencing showed that the range of T-cell clonotypes was very restricted. After T-cell expansion, different TCRBV subfamilies were found to predominate in different target tissues; these included TCRBV 5.1 and 17 in the PB, TCRBV 13 and 21.3 in the bone marrow, and TCRBV 17 in lymph nodes. CDR3 size analysis showed that the expression of different proliferating T-cell clonotypes remained restricted after T-cell expansion. These results indicate that highly restricted maternal T-cell clonotypes can markedly expand, possibly in response to tissue-specific antigens, in a MHC-identical recipient.

Long-term follow-up of hepatitis C virus infection: HLA class II loci influences the natural history of the disease

Hepatitis C virus (HCV) causes various grades of chronic liver disease, ranging from an asymptomatic state to cirrhosis. To assess genetic factors of disease severity, we selected two HCV patient groups according to the following stringent criteria: (i) asymptomatic carrier state (ASC) defined by HCV infection for more than 20 years, normal alanine aminotransferase levels for the past 5 years as well as normal liver histology and/or shape and (ii) liver cirrhosis (LC) as diagnosed by clinical symptoms, liver biopsy and/or ultrasonography. A total of 103 chronically infected Japanese HCV patients (43 ASC and 60 LC) were analyzed. HLA class I and II alleles were established using low resolution DNA typing. HLA-DRB1 and DQB1 genotypes were inferred upon polymerase chain reaction-restriction fragment length polymorphism analysis. Two hundred and one anti-HCV-negative ethnically matched controls were included. The frequencies of DRB1*12 (*1201 and *1202), DQB1*0301 and DRB3*03 alleles were higher in patients with ASC than in those with LC (odds ratio (OR) 11.23, OR 4.25, and OR 3.22, respectively). The frequency of DQB1*0503 were lower in ASC patients compared to LC patients (OR 0.05). No significant differences between groups were observed for age, sex, source of infection, HCV genotype or viral loads. Our findings establish that certain HLA class II alleles strongly influence disease progression following HCV infection.

Peroxisome proliferator-activated receptor gamma ligand troglitazone induces cell cycle arrest and apoptosis of hepatocellular carcinoma cell lines

BACKGROUND

Ligand activation of peroxisome proliferator-activated receptor gamma (PPARgamma) results in the inhibition of proliferation of various cancer cells. The aim of this study is to investigate the mechanisms of cell growth inhibition of hepatocellular carcinoma (HCC) cell lines by the PPARgamma ligand, troglitazone.

METHODS

Six HCC cell lines were used to study the effects of troglitazone on cell growth by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, on cell cycle by flow cytometry, and on the cell cycle-regulating factors of late G1 phase by Western blotting. Apoptosis assays were performed by flow cytometry using membrane, nuclear, cytoplasmic, and mitochondrial markers. Caspase inhibitors were used to analyze the mechanisms of apoptosis induced by troglitazone.

RESULTS

Troglitazone showed a potent dose-dependent effect on the growth inhibition of all six HCC cell lines, which were suppressed to under 50% of control at the concentration of 10 micromol/L. The growth inhibition was linked to the G1 phase cell cycle arrest through the up-expression of the cyclin-dependent kinase inhibitors, p21 and p27 proteins, and the hypophosphorylation of retinoblastoma protein. Troglitazone induced apoptosis by caspase-dependent (mitchondrial transmembrane potential decrease, cleavage of poly [adenosine diphosphate ribose] polymerase, 7A6 antigen exposure, Bcl-2 decrease, and activation of caspase 3) and caspase-independent (phosphatidylserine externalization) mechanisms.

CONCLUSIONS

Our data suggest that ligand activation of PPARgamma by troglitazone or modified analogs of the thiazolidinedione class of drugs is a novel target for effective therapy against HCC, because of the significant antiproliferative and programmed cell death induction capabilities demonstrated by troglitazone.

HLA DRB10405-DQB10401 haplotype is associated with autoimmune pancreatitis in the Japanese population

BACKGROUND & AIMS

Autoimmune pancreatitis is a distinctive disease entity characterized by high serum immunoglobulin G4 concentrations. Because of the close association between some autoimmune diseases and particular alleles of major histocompatibility complex genes, we investigated the association between HLA alleles and autoimmune pancreatitis.

METHODS

HLA-A, -B, -C, -DR, and -DQ gene typing and HLA-DRB1, -DQB1, and -DPB1 allele typing were performed by the polymerase chain reaction sequence-specific primers method and the restriction fragment length polymorphism method, respectively, in 40 patients with autoimmune pancreatitis, 43 patients with chronic calcifying pancreatitis, and 201 healthy subjects.

RESULTS

In patients with autoimmune pancreatitis compared with healthy subjects, we found a significant increase in DR4 (73% vs. 44%, corrected P = 0.01) and DRB1*0405 (58% vs. 21%, corrected P = 0.000026) and DQ4 (58% vs. 26%, corrected P = 0.001) and DQB1*0401 (58% vs. 21%, corrected P = 0.000017). The DRB1*0405-DQB1*0401 haplotype in autoimmune pancreatitis showed no significant association with any HLA class I antigens, in contrast to the B54-DRB1*0405-DQB1*0401 haplotype reported in autoimmune hepatitis. The frequencies of DRB1*0405 and DQB1*0401 were significantly high in patients with autoimmune pancreatitis compared with chronic calcifying pancreatitis.

CONCLUSIONS

It is probable that DRB1*0405-DQB1*0401 haplotype is associated with autoimmune pancreatitis in the Japanese population.

SEN virus: response to interferon alfa and influence on the severity and treatment response of coexistent hepatitis C

The SEN virus (SENV) is a recently identified single-stranded, circular DNA virus. A strong association between 2 SENV variants (SENV-D and SENV-H) and transfusion-associated non-A-to-E hepatitis has been reported. To clarify the effect of SENV infection on coexisting chronic hepatitis C and the effect of interferon alfa (IFN-alpha) therapy on SENV replication, SENV DNA was quantitated by polymerase chain reaction in serum samples from 186 patients with chronic hepatitis C. Thirty-nine of 186 (21%) patients with chronic hepatitis C were positive for SENV DNA. There were no differences in the clinical, virologic and histologic features between patients with and without SENV infection. Eighteen of 102 patients with chronic hepatitis C who received IFN-alpha were positive for SENV DNA. The sustained response rate for hepatitis C virus (HCV) clearance after IFN-alpha treatment did not differ significantly between patients with SENV (28%) and without SENV infection (39%). SENV DNA levels decreased during therapy in 15 of 16 patients, and 11 of the 16 patients (69%) had a sustained loss of SENV DNA in response to IFN-alpha. In coinfected patients, SENV responses to IFN-alpha were significantly better in those who failed to clear HCV RNA than in those who lost HCV RNA (P =.013). In conclusion, SENV infection was frequently found in patients with chronic hepatitis C. SENV infection had no apparent influence on the severity of HCV-related liver disease or the HCV response to IFN-alpha. SENV was sensitive to IFN-alpha therapy and the majority of patients had a sustained virologic response.

Localization of the muscular dystrophy AM locus using a chicken linkage map constructed with the Kobe University resource family

A chicken linkage map, constructed with the Kobe University (KU) resource family, was used to locate the genetic locus for muscular dystrophy of abnormal muscle type (AM). The KU resource family is a backcross pedigree with 55 offspring produced from the mating of a White Leghorn F-line (WL-F) male and a hybrid female produced from a cross between the WL-F male and a female of the Fayoumi OPN line who was homozygous for the AM gene. In total, 872 loci were genotyped on the pedigree; 749 (86%) were informative and mapped to 38 linkage groups. These informative loci included 649 AFLPs, 93 MS, three functional genes, the AM locus, sex phenotype, and two red blood cell loci. The remaining 123 markers were unlinked. Nineteen of the 38 KU linkage groups were assigned to macrochromosomes 1-8 and 11 microchromosomes including chromosome W, while 19 linkage groups were unassigned. The total map was 3569 cM in length, with an average marker interval of 4.8 cM. The AM locus was mapped 130 cM from the distal end of chromosome 2q.

Clinical significance of T.T. virus infection in maintenance hemodialysis patients of an endemic area for hepatitis C infection

Clinical significance of TTV infection was analyzed in Egyptian hemodialysis (HD) patients. Forty-seven Egyptian patients on maintenance HD and 50 age-matched volunteer blood donors were investigated. TT virus (TTV) DNA detection and genotyping were performed using a semi-nested polymerase chain reaction with specific primers. The prevalence of TTV DNA in patients on HD (66%) was significantly (P<0.001) higher than in blood donors (24%) with genotype 1b predominance (89%) in both. Clinical background including mean age, sex, history of blood transfusion, and positive markers for either hepatitis B virus (HBV) or hepatitis C virus (HCV) did not differ between TTV DNA positive and negative HD patients. However, the mean duration of HD was significantly (P=0.032) shorter in the TTV positive patients (28+/-19 months) than in the negative ones (45+/-34 months). Mean alanine aminotransferase level in patients with HCV infection alone (41+/-24 IU/l) did not differ from that in patients with both co-infection (33+/-28 IU/l), but was significantly higher than that in patients with TTV infection alone (26+/-10 IU/l). Occurrence of chronic hepatic changes in patients with TTV infection alone (7%) was significantly less common than those with HCV infection alone (100%, P<0.001) or those with both co-infection (100%, P<0.001). Serum level of HCV core protein was similar between patients with HCV infection alone and those with co-infection with TTV. In conclusion, the prevalence of TTV infection is high in Egyptian patients on regular HD, especially with shorter duration on HD. No clinical significance of TTV virus could be elicited in HD Egyptian patients; neither it showed any clinical impact as a co-infection with HCV.

Energetic feasibility of hydrogen abstraction and recombination in coenzyme B(12)-dependent diol dehydratase reaction

Coenzyme B(12) serves as a cofactor for enzymatic radical reactions. The essential steps in all the coenzyme B(12)-dependent rearrangements are two hydrogen abstraction steps: hydrogen abstraction of the adenosyl radical from substrates, and hydrogen back-abstraction (recombination) of a product-derived radical from 5'-deoxyadenosine. The energetic feasibility of these hydrogen abstraction steps in the diol dehyratase reaction was examined by theoretical calculations with a protein-free, simplified model at the B3LYP/6-311G* level of density functional theory. Activation energies for the hydrogen abstraction and recombination with 1,2-propanediol as substrate are 9.0 and 15.1 kcal/mol, respectively, and essentially not affected by coordination of the substrate and the radical intermediate to K+. Since these energies can be considered to be supplied by the substrate-binding energy, the computational results with this simplified model indicate that the hydrogen abstraction and recombination in the coenzyme B(12)-dependent diol dehydratase reaction are energetically feasible.

Association between SEN virus infection and hepatitis C in Japan

There is a strong association between 2 SEN virus (SENV) variants (SENV-D and SENV-H) and transfusion-associated non-A-E hepatitis. In total, 200 subjects from a Japanese region where hepatitis C virus (HCV) is highly endemic and 194 persons from a contiguous area where HCV is not endemic were tested for SENV-D and SENV-H DNA by polymerase chain reaction. SENV DNA was detected equally in subjects from each area (56% prevalence in the area of high endemicity vs. 61% in the nonendemic area). Age-specific prevalence of SENV was similar to that of TT virus, with equal distribution at all ages in both areas; HCV was predominant in the elderly population. Alanine aminotransferase levels were significantly associated with HCV viremia but not with SENV viremia. SENV is a common infection that appears to have transmission routes and age-related prevalence that are distinct from those of HCV. No evidence was found that SENV caused hepatitis or worsened the course of hepatitis C.

A case with myasthenia gravis (MG) emerging after splenectomy for idiopathic thrombocytopenic purpura (ITP): possible effects of thymectomy on autoantibodies

The combination of idiopathic thrombocytopenic purpura (ITP) and myasthenia gravis (MG) has been reported infrequently. We report here the development of MG in a patient who underwent splenectomy for ITP ten years earlier, and describe the serum levels of anti-acetylcholine receptor antibodies (anti-AchR) and platelet-associated IgG (PAIgG) followed over 11 years. The concentrations of both autoantibodies have been decreased after thymectomy, suggesting that this procedure is potentially beneficial for treating both MG and ITP.

Relationship between hepatitis C virus infection and schistosomal liver disease: not simply an additive effect

BACKGROUND

To study the association, clinical significance, and impact of hepatitis C virus (HCV) co-infection in patients with schistosomal liver disease (SLD).

METHODS

A total of 240 patients with chronic liver diseases encountered consecutively were enrolled in the study. Fifty volunteer blood donors were enrolled as controls. HCV antibody determination (enzyme-linked immunosorbent assay), qualitative and quantitative HCV RNA assay (reverse transcriptase polymerase chain reaction), and HCV genotyping (line probe assay) were performed.

RESULTS

Twenty-eight patients had SLD alone, 60 had both SLD and chronic hepatitis C (CH-C), 120 had CH-C alone, and 32 had other liver diseases. The positivity rates for HCV antibody (76% vs 20%; P < 0.001) and HCV RNA (59% vs 10%; P < 0.001) were significantly higher in the patients with SLD (n = 88) than in the volunteer blood donors (n = 50). Complications of liver cirrhosis were more common in patients with concomitant SLD and CH-C than in those with either SLD or CH-C alone. The mean levels of alanine aminotransferase (77 +/- 42 vs 93 +/- 55 IU/l; P = 0.049) and HCV RNA concentrations (3.5 +/- 1.0 vs 4.2 +/- 1.0 log copy/ml; P < 0.001) were significantly lower in patients with concomitant SLD and CH-C than in those with CH-C alone. HCV genotype 4 predominated in both these groups (93% and 98%).

CONCLUSIONS

SLD in Egypt is significantly associated with HCV infection, with the predominance of genotype 4. Concurrent HCV infection and SLD result in much more severe liver disease than that seen with either disease alone. However, the activity of HCV infection seems to be partially suppressed in patients with SLD.

A theoretical study of the dynamic behavior of alkane hydroxylation by a compound I model of cytochrome P450

Dynamic aspects of alkane hydroxylation mediated by Compound I of cytochrome P450 are discussed from classical trajectory calculations at the B3LYP level of density functional theory. The nuclei of the reacting system are propagated from a transition state to a reactant or product direction according to classical dynamics on a Born-Oppenheimer potential energy surface. Geometric and energetic changes in both low-spin doublet and high-spin quartet states are followed along the ethane to ethanol reaction pathway, which is partitioned into two chemical steps: the first is the H-atom abstraction from ethane by the iron-oxo species of Compound I and the second is the rebound step in which the resultant iron-hydroxo complex and the ethyl radical intermediate react to form the ethanol complex. Molecular vibrations of the C-H bond being dissociated and the O-H bond being formed are significantly activated before and after the transition state, respectively, in the H-atom abstraction. The principal reaction coordinate that can represent the first chemical step is the C-H distance or the O-H distance while other geometric parameters remain almost unchanged. The rebound process begins with the iron-hydroxo complex and the ethyl radical intermediate and ends with the formation of the ethanol complex, the essential process in this reaction being the formation of the C-O bond. The H-O-Fe-C dihedral angle corresponds to the principal reaction coordinate for the rebound step. When sufficient kinetic energy is supplied to this rotational mode, the rebound process should efficiently take place. Trajectory calculations suggest that about 200 fs is required for the rebound process under specific initial conditions, in which a small amount of kinetic energy (0.1 kcal/mol) is supplied to the transition state exactly along the reaction coordinate. An important issue about which normal mode of vibration is activated during the hydroxylation reaction is investigated in detail from trajectory calculations. A large part of the kinetic energy is distributed to the C-H and O-H stretching modes before and after the transition state for the H-atom abstraction, respectively, and a small part of the kinetic energy is distributed to the Fe-O and Fe-S stretching modes and some characteristic modes of the porphyrin ring. The porphyrin marker modes of nu(3) and nu(4) that explicitly involve Fe-N stretching motion are effectively enhanced in the hydroxylation reaction. These vibrational modes of the porphyrin ring can play an important role in the energy transfer during the enzymatic process.

Changes in the levels of glutathione after cellular and cutaneous damage induced by squalene monohydroperoxide

Squalene monohydroperoxide (Sq-OOH), the initial product of ultraviolet-peroxidated squalene, was used to investigate the effect of peroxidative challenge upon the glutathione contents in rabbit ear skin and primary-cultured fibroblasts derived from rabbit ear skin. The cellular reduced glutathione (GSH) contents decreased during 30-minute incubations in vitro with Sq-OOH, and oxidized glutathione (GSSG) was formed concomitantly, indicating that Sq-OOH had a potential for GSH-depleting activity in vitro. When Sq-OOH was applied topically to the skin in vivo, only GSSG contents increased significantly within 30 minutes. Moreover, pretreatment with the GSH depletors, DL-buthionine sulfoximine (BSO) and diethyl maleate (DEM), could potentiate the cytotoxicity and comedogenicity induced by Sq-OOH. These findings suggest that the endogenous antioxidant, glutathione, is quite sensitive to Sq-OOH and may be an important material for protecting cells and/or tissues against the oxidative stress induced by Sq-OOH treatment.