Shunzo Koizumi

Inverse association between coffee drinking and the risk of hepatocellular carcinoma: a case‐control study in Japan

Coffee use has consistently been associated with lower serum liver enzyme levels and a reduced risk of liver cirrhosis. A limited number of cohort and case‐control studies also suggest a decreased risk of hepatocellular carcinoma (HCC) among coffee drinkers, but mostly without consideration of hepatitis virus infection. In the present case‐control study, we recruited 209 incident HCC cases and three different controls (1308 community controls, 275 hospital controls, and 381 patients with chronic liver disease [CLD] without HCC), all of whom were aged 40–79 years and residents of Saga Prefecture, Japan. A questionnaire survey elicited information on coffee use during the last 1–2 years and 10 years before, and plasma hepatitis B surface antigen and antibodies to hepatitis C virus were tested for all but community controls. After adjustment for sex, age, heavy alcohol use, smoking status and hepatitis virus markers (except for community controls), coffee use during the last 1–2 years was associated with a decreased risk against any control group. For coffee use 10 years before, comparison between HCC cases and either community controls or CLD patients revealed a decreased risk; adjusted odds ratios for occasional use, 1–2 cups/day and ≥3 cups/day compared with no use were 0.33, 0.27 and 0.22 (P trend < 0.001), respectively, against community controls, and 0.86, 0.62 and 0.53 (P trend = 0.05), respectively, against CLD patients. These results suggest that coffee may protect against the development of HCC, yet further elaborate studies (hopefully, intervention studies) are warranted to corroborate these findings. (Cancer Sci 2007; 98: 214–218)

Medical student abuse during clinical clerkships in Japan

AbstractOBJECTIVE: To assess the prevalence of medical student abuse during clinical clerkships in Japan.n DESIGN: A cross-sectional questionnaire survey.n SETTING: Six medical schools in Japan.n PARTICIPANTS: Final year (sixth-year) and fifth-year medical students in the period from September 2003 to January 2004. From a total of 559 students solicited, 304 (54.4%) returned the questionnaire, and 276 (49.4%: 178 male and 98 female) completed it.n MEASUREMENTS: Prevalence of medical student abuse in 5 categories: verbal abuse, physical abuse, academic abuse, sexual harassment, and gender discrimination; differences in abusive experience between male and female students; types of alleged abusers; reporting abusive experiences to authorities; and emotional effects of abusive experiences.n RESULTS: Medical student abuse was reported by 68.5% of the respondents. Verbal abuse was the most frequently experienced abuse (male students 52.8%, female students 63.3%). Sexual harassment was experienced significantly more often (P<.001) by female students (54.1%) than by male students (14.6%). Faculty members were most often reported as abusers (45.2% of cases). Abuse occurred most frequently during surgical rotations (42.0% of cases), followed by internal medicine (25.1%) and anesthesia rotations (21.8%). Very few abused students reported their abusive experiences to authorities (8.5%). The most frequent emotional response to abuse was anger (27.1% of cases).n CONCLUSIONS: Although experience of abuse during clinical clerkships is common among medical students in Japan, the concept of “medical student abuse” is not yet familiar to Japanese. To improve the learning environment, medical educators need to take action to resolve this serious issue.

Influence of alcohol consumption and gene polymorphisms of ADH2 and ALDH2 on hepatocellular carcinoma in a Japanese population.

Although alcohol intake as well as hepatitis viruses has been associated with hepatocellular carcinoma (HCC), gene–alcohol interactions on HCC risk remain to be elucidated. We conducted a case‐control study to examine whether polymorphisms of alcohol dehydrogenase 2 (ADH2) and aldehyde dehydrogenase 2 (ALDH2) modified the HCC risk depending on the amount of alcohol intake. ADH2 and ALDH2 genotyping was performed by a duplex polymerase chain reaction with confronting two‐pair primers in 209 newly diagnosed HCC cases and 2 different controls [275 hospital controls and 381 patients with chronic liver disease (CLD)]. Multiple logistic regression analyses revealed that heavy drinkers consuming ≥3 “go”s/day of sake (69 g of ethanol/day) showed an increased risk of HCC based on comparison of HCC cases with hospital controls [adjusted odds ratio (OR) = 13.5; 95% confidence interval (CI) 3.3–54.3] or CLD patients (adjusted OR = 7.0; 95% CI 2.5–19.2), whereas the overall risk was not elevated among light to moderate drinkers consuming <3 “go”s/day. Interestingly, light to moderate drinking was associated with an increased risk among those with ALDH2*1/*2 (adjusted OR = 4.5 or 2.0), but not among those with ALDH2*1/*1 (adjusted OR = 0.8 or 1.0; p interaction = 0.03 or 0.13). However, this gene–alcohol interaction was not observed for heavy drinking. Among light to moderate drinkers, people with the combination of ALDH2*1/*2 and ADH2*2/*2 revealed the highest risk of HCC. These findings indicate that the ALDH2 polymorphism may modify HCC risk among light to moderate drinkers.

A prospective analysis of the factors influencing pancreaticojejunostomy performed using a single method, in 100 consecutive pancreaticoduodenectomies

The factors influencing the healing process of pancreaticojejunostomy (P-J) following pancreaticoduodenectomy (PD) are still ill defined, allowing the recommendation of various anastomotic methods. We conduced a prospective study to determine the risk factors influencing the protracted healing of P-J, examining 100 consecutive patients who underwent PD followed by P-J, performed as an end-to-side “mucosa-to-mucosa” anastomosis using vertical mattress sutures (VMS method). Protracted healing of P-J was classified as either peripancreatic sepsis (PPS), defined as prolonged suppurative discharge of less than 50 ml a day from the drain beneath the P-J for more than 1 week; or a pancreatic fistula (PF), defined as prolonged discharge of more than 50 ml a day with a high amylase content (>1000 IU) for more than 1 week. There were 80 patients with a malignant neoplasm, and 20 with benign disease. The overall incidence of healing problems following P-J was 9%, which included 6 patients (6%) with PPS and 3 (3%) with PF. Apart from an advanced age of more than 70 years, none of the patients characteristics or postoperative complications influenced the healing of P-J. The type of reconstruction, an anastomotic stent, the duct size, and a “soft” pancreas were not risk factors either. In conclusion, no factors, apart from the age or any special problem of an individual patient, influenced the dehiscence of P-J when the VMS method was used after PD.

The pathological role of visceral fat accumulation in steatosis, inflammation, and progression of nonalcoholic fatty liver disease

BackgroundOur previous studies have indicated a close association between visceral fat accumulation and hepatic steatosis in nonalcoholic fatty liver disease (NAFLD). This study investigated whether visceral fat accumulation was related to the pathogenesis and disease progression of nonalcoholic steatohepatitis (NASH)/NAFLD.MethodsFirst, a total of 550 subjects who underwent a health checkup and measurement of visceral fat accumulation, done with a bioelectrical impedance analyzer (X-SCAN; Owa Medical, Fukuoka, Japan), were included. The relationship between visceral fat accumulation and biochemical parameters was examined. Second, a total of 74 patients with NASH/NAFLD who underwent liver biopsy were reviewed. Visceral fat accumulation was determined by abdominal computed tomography. The association between visceral fat accumulation and the histopathological grade/stage determined by the NAFLD activity score and Brunt’s classification was evaluated.ResultsThere was a significant relationship between visceral fat accumulation and glucose, triglyceride, and alanine aminotransferase (ALT; rxa0=xa00.423, Pxa0<xa00.01). In stepwise regression analysis, visceral fat area (VFA), serum triglyceride level, and serum low-density lipoprotein (LDL)-cholesterol level were selected as predictor variables for serum ALT level, in a continuous manner (serum ALT levelxa0=xa0−1.359xa0+xa00.143xa0×xa0VFAxa0+xa00.046xa0×xa0triglyceridexa0+xa00.059xa0×xa0LDL, R2xa0=xa00.217, Pxa0<xa00.001). In patients with NASH, there was no correlation between histological grade and the visceral fat volume. Visceral fat accumulation in patients with stage 3/4 advanced NASH was greater than that in patients with stage 1/2 early NASH (Pxa0<xa00.05).ConclusionsThese results suggest that visceral fat accumulation plays a role in steatosis and fibrosis in the pathogenesis and prognosis of NAFLD.

Interaction between cytochrome P450 1A2 genetic polymorphism and cigarette smoking on the risk of hepatocellular carcinoma in a Japanese population

Limited epidemiological evidence suggests that genetic polymorphisms of drug-metabolizing enzymes such as cytochrome P450 (CYP), glutathione S-transferase (GST) and N-acetyltransferase (NAT) may be involved in tobacco-related hepatocarcinogenesis. We conducted a case-control study, including 209 incident cases with hepatocellular carcinoma (HCC) and two different control groups [275 hospital controls and 381 patients with chronic liver disease (CLD) without HCC], to investigate whether CYP1A1, CYP1A2, CYP2A6, CYP2E1, GSTM1 and NAT2 polymorphisms are related to the risk of HCC with any interaction with cigarette smoking. Overall, no significant associations with HCC were observed for any genotypes against either control group. However, we found a significant interaction (P = 0.0045) between CYP1A2 -3860G>A polymorphism and current smoking on HCC risk when we compared HCC cases with CLD patients; adjusted odds ratios [ORs; and 95% confidence intervals (CIs)] for G/A and A/A genotypes relative to G/G genotype were 0.28 (0.12-0.66) and 0.18 (0.04-0.94), respectively, among current smokers (P trend = 0.002), as compared with 1.28 (0.80-2.06) and 0.76 (0.34-1.71), respectively, among never/former smokers (P trend = 0.96). Similarly, in CYP1A2 G/G genotype, significant risk increase was observed for current smoking (OR = 4.08, 95% CI = 2.02-8.25) or more recent cigarette use (e.g. pack-years during last 5 years, P trend = 0.0003) but not in G/A and A/A genotypes combined (OR for current smoking = 1.39, 95% CI = 0.63-3.03; P trend for pack-years during last 5 years = 0.40). These results suggest that the CYP1A2 -3860G>A polymorphism modifies the smoking-related HCC risk among CLD patients.

Case–control study on cigarette smoking and the risk of hepatocellular carcinoma among Japanese

Emerging epidemiologic data suggest that cigarette smoking may increase the risk of hepatocellular carcinoma (HCC), yet considerable controversies (e.g. inconsistent dose–response relationships) still exist with this association. We examined whether smoking was associated with HCC risk in a case–control study including 209 incident HCC cases and two different control groups (256 hospital controls and 381 patients with chronic liver disease [CLD] without HCC). Comparison of HCC cases with CLD patients, but not with hospital controls, demonstrated a significantly increased risk of HCC for current smokers. After adjustment for sex, age, heavy drinking history and hepatitis virus markers, odds ratios (and 95% confidence intervals) for former and current smokers relative to never smokers were 1.0 (0.6–1.7) and 2.5 (1.4–4.6), respectively, against CLD patients, as compared with 0.8 (0.3–2.3) and 1.8 (0.6–5.1), respectively, against hospital controls. In terms of pack‐years during lifetime, dose–response relationship was not evident against either control group (P trend = 0.43), but it became clearer for more recent cigarette use among CLD patients. For example, regarding cumulative cigarette consumption during the last 5 years, adjusted odds ratios (and 95% confidence intervals) for 1–4 and 5+ pack‐years relative to no use were 1.9 (1.1–3.6) and 2.8 (1.5–5.2) (P trend = 0.003), respectively. These results suggest that cigarette smoking may play a crucial role in the late stage of HCC development and that CLD patients may benefit from their earliest smoking cessation. (Cancer Sci 2008; 99: 93–97)

Interaction between interleukin-1β −31T/C gene polymorphism and drinking and smoking habits on the risk of hepatocellular carcinoma among Japanese

The risk of hepatocellular carcinoma (HCC) increases with the severity of hepatic inflammation. Interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha are proinflammatory cytokines with multiple biological effects and may play essential roles in inflammation-linked tumor development. We conducted a case-control study including 209 incident HCC cases and two control groups (275 hospital controls and 381 patients with chronic liver disease [CLD] without HCC) to investigate whether IL-1B and TNF-A gene polymorphisms influence HCC susceptibility with any interaction with alcohol and tobacco. By comparing HCC cases with CLD patients, we found that IL-1B -31T/C polymorphism was associated with HCC risk among never drinkers and current smokers; adjusted odds ratios (and 95% confidence intervals) for C/T and T/T genotypes compared with C/C genotype were 1.70 (0.76-3.77) and 2.46 (1.05-5.76) (P trend=0.03), respectively, among never drinkers, and 1.53 (0.60-3.99) and 2.54 (0.81-7.95) (P trend=0.11), respectively, among current smokers. Similarly, HCC risk associated with heavy alcohol intake and current smoking differed by this polymorphism among CLD patients. IL-1B -31T/C polymorphism may modify HCC risk in relation to alcohol intake or smoking.

STATUS OF MEDICAL EDUCATION REFORM AT SAGA MEDICAL SCHOOL 5 YEARS AFTER INTRODUCING PBL

In Japan, problem‐based learning (PBL) is a relatively new method of educating medical students that is reforming the face of medical education throughout the world, including Asia. It shifts from teacher‐centered learning strategies (for example, lectures in large auditoriums) to student‐centered, self‐directed learning methods (for example, active discussions and problem‐solving by students in small groups under the guidance of faculty tutors). Upon a recommendation by the Japan Model Core Curriculum, Saga Medical School introduced a PBL curriculum 5 years ago. A full PBL curriculum was adopted from the McMaster model through Hawaii. A description of how PBL was implemented into the 3rd and 4th year (Phase III curriculum) is given. The overall result has been good. Students who experienced PBL had increased scores on the National Medical License Exam, and Saga increased its ranking from 56th to 19th of the 80 medical schools in Japan. A key step was introduction of the educational scaffolding in PBL Step 0. Students were allowed to see page one of the PBL case, containing the chief complaint, on the weekend before meeting in small groups. Despite a perceived overall benefit to student learning, symptoms of superficial discussions by students have been observed recently. How this may be caused by poor case design is discussed. Other problems, including “silent tutors” and increased faculty workload, are discussed. It is concluded that after 5 years, Sagas implementation of a PBL curriculum has been successful. However, many additional issues, including motivation of students and preparation for PBL in the first 2 years, must still be resolved in the future. This is the first description of the positive and negative outcomes associated with the reform of medical education and the introduction of PBL to a traditional medical school curriculum in Japan.

hOGG1 Ser326Cys Polymorphism and Risk of Hepatocellular Carcinoma among Japanese

BACKGROUND The Ser326Cys polymorphism in human oxoguanine glycosylase 1 (hOGG1), which is involved in the repair of 8-hydroxy-2-deoxyguanine in oxidatively damaged DNA, has been associated with susceptibility to certain cancers, but has not been examined in causation of hepatocellular carcinoma (HCC). METHODS We conducted a case-control study to investigate whether this polymorphism was related to HCC risk with any interaction with alcohol consumption and cigarette smoking. Genotyping was performed by a polymerase chain reaction with confronting two-pair primers among 209 newly diagnosed HCC cases, 275 hospital controls, and 381 patients with chronic liver disease (CLD) without HCC. RESULTS Overall, the hOGG1 genotype was not significantly associated with HCC; adjusted odds ratios (and 95% confidence intervals) for the Ser/Cys and Cys/Cys genotypes compared with the Ser/Ser genotype were 0.79 (0.35-1.79) and 0.48 (0.18-1.27) against hospital controls, and 1.51 (0.96-3.37) and 0.86 (0.50-1.47) against CLD patients. We could not detect any significant gene-alcohol interaction (p = 0.95 or 0.16) or gene-smoking interaction (p = 0.70 or 0.69). CONCLUTIONS These results suggest that the hOGG1 Ser326Cys polymorphism may not play a major role as an independent factor in hepatocarcinogenesis.