Detection of current-sheet and bipolar ion flows in a self-generated antiparallel magnetic field of laser-produced plasmas for magnetic reconnection research.

Magnetic reconnection in laser-produced magnetized plasma is investigated by using optical diagnostics. The magnetic field is generated via the Biermann battery effect, and the inversely directed magnetic field lines interact with each other. It is shown by self-emission measurement that two colliding plasmas stagnate on a midplane, forming two planar dense regions, and that they interact later in time. Laser Thomson scattering spectra are distorted in the direction of the self-generated magnetic field, indicating asymmetric ion velocity distribution and plasma acceleration. In addition, the spectra perpendicular to the magnetic field show different peak intensity, suggesting an electron current formation. These results are interpreted as magnetic field dissipation, reconnection, and outflow acceleration. Two-directional laser Thomson scattering is, as discussed here, a powerful tool for the investigation of microphysics in the reconnection region.

High-power laser experiment on developing supercritical shock propagating in homogeneously magnetized plasma of ambient gas origin.

A developing supercritical collisionless shock propagating in a homogeneously magnetized plasma of ambient gas origin having higher uniformity than the previous experiments is formed by using high-power laser experiment. The ambient plasma is not contaminated by the plasma produced in the early time after the laser shot. While the observed developing shock does not have stationary downstream structure, it possesses some characteristics of a magnetized supercritical shock, which are supported by a one-dimensional full particle-in-cell simulation taking the effect of finite time of laser-target interaction into account.

Direct observations of pure electron outflow in magnetic reconnection.

Magnetic reconnection is a universal process in space, astrophysical, and laboratory plasmas. It alters magnetic field topology and results in energy release to the plasma. Here we report the experimental results of a pure electron outflow in magnetic reconnection, which is not accompanied with ion flows. By controlling an applied magnetic field in a laser produced plasma, we have constructed an experiment that magnetizes the electrons but not the ions. This allows us to isolate the electron dynamics from the ions. Collective Thomson scattering measurements reveal the electron Alfvénic outflow without ion outflow. The resultant plasmoid and whistler waves are observed with the magnetic induction probe measurements. We observe the unique features of electron-scale magnetic reconnection simultaneously in laser produced plasmas, including global structures, local plasma parameters, magnetic field, and waves.

Review and pooled analysis of studies on MTHFR C677T polymorphism and esophageal cancer.

Esophageal cancer has been associated with tobacco and alcohol consumption, gastric reflux, exposure to nitrosamines from food or other environmental sources, and diets lacking folate. Susceptibility to esophageal cancer may be modified by functional polymorphisms in genes along the folate metabolic pathway, such as methylenetetrahydrofolate reductase (MTHFR). The C677T polymorphism is the most common functional variant, leading to a reduction in enzyme activity. We report a pooled analysis of 5 studies on the association of MTHFR C677T polymorphism and esophageal cancer, including 725 cases and 1531 controls. A significant association between the MTHFR 677 TT genotype and esophageal cancer was observed (OR=2.63, 95% CI: 1.75-3.94), although there was significant heterogeneity between studies. A sensitivity analysis excluded one study; the association between TT genotype and esophageal cancer was still present, although of reduced magnitude (OR=1.57, 95% CI: 0.96-2.56). A significant interaction between smoking and TT genotype on esophageal cancer risk was observed, while no interaction was observed between alcohol consumption and genotype.

Microscale multiple scattering of coherent surface acoustic wave packets probed with gigahertz time-reversal acoustics.

The multiple scattering of coherent surface acoustic wave packets in a microstructure is studied using an ultrafast optical technique. By recording a set of acoustic transfer functions, we show that it is possible to implement time-reversal acoustics and refocus the wave packets up to the GHz range, two orders of magnitude higher than usual. Many applications in time-reversal acoustics are thus transposable to correspondingly smaller structures, opening the way to efficient nondestructive characterization and manipulation of multiple scattering on the microscale.

Fish consumption and colorectal cancer: a case-reference study in Japan.

Several clinical studies have suggested that supplementation with fish oils can suppress the proliferation of colorectal mucosa and therefore inhibit the development of colorectal cancer. However, epidemiological evidence concerning fish consumption and risk is inconsistent and limited. To clarify the association between intake of fish and the likelihood of developing colorectal cancer, we conducted a large sample size case-reference study with 928 cases of colon cancer, 622 of rectal cancer and 46886 cancer-free outpatient references aged 40-79 years. The data showed frequent raw/cooked fish intake to be associated with decreased odds ratio (OR) 0.68 with 95% confidence interval (CI) 0.47-0.99 for male colon cancer, especially for males aged over 60 years, smokers and frequent meat eaters. A marginal decrease in the OR (OR 0.58, 95% CI 0.31-1.07) was also detected for female rectal cancer, especially in the regular physical exercise subgroup. However, frequent dried/salted fish intake was found to be associated with increased OR in females younger than 60 years old and alcohol drinkers. Although there is some possible bias in epidemiological studies, the results suggest that frequent raw/cooked fish intake may decrease the risk while dried/salted fish, in contrast, may exert a detrimental effect.

Association of polymorphisms in the beta-2 and beta-3 adrenoceptor genes with risk of colorectal cancer in Japanese.

BACKGROUND: The adrenergic receptor system is involved in thermogenesis and in the activation of lipid mobilization in fat cells, and polymorphisms in the beta-2 and beta-3 adrenoceptor genes (BAR2 and BAR3) have been reported to be associated with obesity and insulin resistance. To examine links between polymorphisms in these genes and the risk of colorectal cancer in Japanese, we conducted the present hospital-based case-referent study. METHODS: Mutations of the BAR2 gene at codon 27 (Gln27Glu) and of the BAR3 gene at codon 64 (Trp64Arg) were examined in 131 patients with colorectal cancer (cases) and in 239 cancer-free referents. We also collected information on environmental factors, using a questionnaire approach. Odds ratios (ORs) were estimated with an unconditional logistic model, after adjustment for potential confounding factors. RESULTS: The proportional distribution of the mutations in BAR2 and BAR3 did not differ between cases and referents. Analysis of a subgroup with a higher body mass index showed that the Trp64Arg variant increased the OR (2.63; 95% confidence interval, 1.13-6.11) for colon cancer, but not for rectal cancer, compared with the Trp64 genotype. Altered ORs for colon and rectal cancers with the Gln27Glu variant were not observed in either the subgroup with the lower body mass index or the subgroup with the higher body mass index. CONCLUSION: These findings suggest that the BAR3 polymorphism may alter the susceptibility to colon cancer risk in obese subjects. To confirm this finding, a further study with a larger number of subjects is now required.

Smoking and lung cancer risk in American and Japanese men: an international case-control study.

Rates of lung cancer in American men have greatly exceeded those in Japanese men for several decades despite the higher smoking prevalence in Japanese men. It is not known whether the relative risk of lung cancer associated with cigarette smoking is lower in Japanese men than American men and whether these risks vary by the amount and duration of smoking. To estimate smoking-specific relative risks for lung cancer in men, a multicentric case-control study was carried out in New York City, Washington, DC, and Nagoya, Japan from 1992 to 1998. A total of 371 cases and 373 age-matched controls were interviewed in United States hospitals and 410 cases and 252 hospital controls in Japanese hospitals; 411 Japanese age-matched healthy controls were also randomly selected from electoral rolls. The odds ratio (OR) for lung cancer in current United States smokers relative to nonsmokers was 40.4 [95% confidence interval (CI) = 21.8-79.6], which was >10 times higher than the OR of 3.5 for current smokers in Japanese relative to hospital controls (95% CI = 1.6-7.5) and six times higher than in Japanese relative to community controls (OR = 6.3; 95% CI = 3.7-10.9). There were no substantial differences in the mean number of years of smoking or average daily number of cigarettes smoked between United States and Japanese cases or between United States and Japanese controls, but American cases began smoking on average 2.5 years earlier than Japanese cases. The risk of lung cancer associated with cigarette smoking was substantially higher in United States than in Japanese males, consistent with population-based statistics on smoking prevalence and lung cancer incidence. Possible explanations for this difference in risk include a more toxic cigarette formulation of American manufactured cigarettes as evidenced by higher concentrations of tobacco-specific nitrosamines in both tobacco and mainstream smoke, the much wider use of activated charcoal in the filters of Japanese than in American cigarettes, as well as documented differences in genetic susceptibility and lifestyle factors other than smoking.

Dietary protective and risk factors for esophageal and stomach cancers in a low-epidemic area for stomach cancer in Jiangsu Province, China: comparison with those in a high-epidemic area.

Comparative epidemiological studies with ecological and case-control approaches in high- and low-epidemic areas of China have provided us with much evidence with regard to risk and benefit in the environment. To clarify how dietary factors are involved in esophageal and stomach cancer development, we performed a case-control study in a low-epidemic area, and compared the findings with those obtained earlier for a high-epidemic area for stomach cancer in the same Jiangsu Province, China. We recruited 199 and 187 cases with esophageal and stomach cancers, respectively, and 333 population-based common controls. Odds ratios (ORs) for esophageal and stomach cancers were calculated with adjustment for potential confounding factors, using an unconditional logistic model. Current and former smoking elevated the OR for esophageal cancer, along with high intake of pickled vegetables and broiled meat, while decreased ORs were observed for frequently consumed raw vegetables and garlic. With regard to stomach cancer, ORs were increased with frequent consumption of salty fish, leftover gruel, and broiled meat, and lowered by snap bean consumption. The present risk factors were common to the previously obtained results in the high-epidemic area, and similarly distributed in each general population. While more protective factors were observed in the high-epidemic area, their penetrance was much greater in the low-epidemic area. The present study thus suggests that frequent vegetable and garlic consumption contributes to low mortality rates for esophageal and stomach cancers in a low-epidemic area, counteracting similar exposure levels for risk factors as in the high-epidemic area.

[Association between the interleukin 1B (C-31T) polymorphism and Helicobacter pylori infection in health checkup examinees].

PURPOSE: Associations between Helicobacter pylori (HP) infection and lifestyle factors have been demonstrated by several studies, but there are very few reports on links with host factors, especially concerning genetic polymorphisms for inhabitants of large city. The present investigation was conducted to determine the HP infection rate with reference to the Interleukin-1 beta gene (IL-1B) polymorphism and assess the interactions with smoking reported for outpatients. METHOD: The subjects were 468 participants in a health-check-up program of law of health for aged conducted by Nagoya Nishi Health Center. The participants were asked to permit use of their residual blood drawn during a health-check-up program and written informed consent was obtained for gene polymorphism tests. Data on smoking habit were obtained by self-administered questionnaire. The IL-1B C-to-T polymorphism at -31 was genotyped by PCR-CTPP (polymerase chain reaction with confronting two-pair primers) and an anti-HP IgG antibody test was used for detecting HP infection. Differences in values were assessed by a chi 2 test. An unconditional logistic model was applied for estimating odds ratios with the computer program STATA Version 6. This study was approved by the Ethical Committee at Aichi Cancer Center in 2000 before it was commenced (Ethical Committee Approval Number 11-12) RESULTS: The HP infection rate was 52.6% (61/116) for the C/C genotype of IL-1B-31, 48.6% (89/183) for the C/T, and 63.2% (103/163) for T/T; the difference were not statistically significant. However, when non-current smokers were excluded, the rate were 47.8% (11/23), 52.9% (18/34), and 72.7% (16/22), respectively, indicating the T/T genotype to have a higher infection rate. The age-sex-smoking adjusted odds ratio (OR) relative to the C/C genotype were 0.97 (95% confidence interval, 0.59-1.57) for the T/C genotype and 1.73 (1.04-2.87) for the T/T genotype. Among current and former smokers the age-sex adjusted OR were 1.68 (0.50-5.71) for the T/C genotype and 5.29 (1.11-25.1) for the T/T genotype, suggesting a effect of this polymorphism prominent in smokers. CONCLUSION: An association between the IL-1B-31 polymorphism and persistent HP infection was observed for inhabitants with a smoking habit, indicating that this polymorphism is one genetic trait conferring an increased likelihood of persistent HP infection.

Alcohol, smoking, and dietary status and susceptibility to malignant lymphoma in Japan: results of a hospital-based case-control study at Aichi Cancer Center.

Recent increase in the incidence of malignant lymphoma (ML) suggests possible involvement of lifestyle or environmental factors in its genesis. However, evidence for an effect of lifestyle factors, especially diet, on ML risk among Japanese is lacking. To explore the possibility that lifestyle factors exert an influence, we have conducted a hospital-based case-control study with 333 histologically confirmed ML cases and 55904 non-cancer controls who first visited Aichi Cancer Center Hospital between 1988 and 1997. Multiple logistic regression analysis showed regular alcohol consumption to be associated with reduced risk of ML, whereas no risk change was observed for smoking. Some other factors including intake of vegetables (carrots and pumpkin), pork and fish showed partial associations, but their significance needs further clarification. From the previous study on genetic background for ML [Matsuo et al., Blood, 97, 3205 - 3209 (2001)], genetic variation combined with limited environmental factors should be targeted in future studies.

[The medical team approach to the suicide--attempted patients by taking drugs or chemicals--participation of the medical social workers].

There are many suicide-attempted patients admitted to the critical care medical center of the Kitakyushu General Hospital. Suicide-attempted patients need psychosocial intervention from the beginning of their hospitalization, because they have their own psychosocial problems. Accordingly, medical social workers (MSW) give psychosocial assistance to the patients in our critical care medical center. In 1997, we participated in the treatment of 53 patients out of 64 suicide-attempted patients. Forty-four patients committed suicide by ingesting some drugs or poisons, and 9 patients committed suicide by jumping from a height or by self-burning. Kinds of drugs or chemicals used for suicide were medicinal drugs (55.3%), household medicines (14.9%), agricultural chemicals (10.7%), insecticides (8.5%), detergents (4.3%), household chemicals (4.3%) and others (2.0%). The largest number of male patients was in their fifties (6 out of 15 male patients). Patients with alcoholism held the first place in male patients. The largest number of female patients was in their twenties (11 out of 29 female patients). There were many female patients with mood disorder, drug dependence or psychopathy. If the patients are discharged without receiving psychosocial measures, it may be every possibility that the patients commit suicide again. MSW make the cause of suicide clear and assess the mental status, and also have interview with patient's families. If both MSW and the doctors in charge judge that there is high possibility of repeated suicide, MSW introduce the patient to the special hospital under the consent of the patient and families. Thirty-five patients out of 44 patients transferred to the psychiatric hospitals. It is important that MSW join the treatment of suicide-attempted patients in order to prevent repeated suicide.

Association of family history and other risk factors with breast cancer risk among Japanese premenopausal and postmenopausal women.

OBJECTIVES: To determine the impact of family history (FH) on anthropometric and reproductive risk factors for breast cancer, a case-referent study was conducted using data from the Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC), Japan. METHODS: In total, 1584 breast cancer cases were included and 15,331 women, confirmed as free of cancer, were recruited as the referents. Odds ratios and 95% confidence intervals were determined by logistic regression analysis. Separate analyses were performed for premenopausal and postmenopausal women. RESULTS: Height, weight, and current body mass index (BMI) were positively associated with postmenopausal breast cancer regardless of FH, while these anthropometric factors did not alter risk in premenopausal women. The impacts of height and weight on postmenopausal breast cancer were more pronounced among FH women. There was little association with reproductive risk factors for premenopausal or postmenopausal breast cancer in FH cases, in clear contrast to the non-FH cases. CONCLUSIONS: These findings suggest some differences in risk impact of common etiologic factors between familial breast cancer and sporadic cases that may give pointers to further analysis of host-specific factors. They imply that avoidance of obesity after menopause may reduce the risk of breast cancer, regardless of FH.

Possible risk reduction in esophageal cancer associated with MPO -463 A allele.

Myeloperoxidase (MPO), an enzyme found in lysosomes of phagocytes, causes hydroxy radicals linked to DNA damage and activation of smoking related carcinogens. A -463 G/A polymorphism in the promoter region of the MPO gene results in reduced gene expression, which would imply lower susceptibility of esophageal cancer in mutant carriers. We conducted case-control study to test this hypothesis. Cases were 91 patients with esophageal cancer and controls were 241 non-cancer outpatients. MPO genotypes were examined by PCR-RFLP. The allele frequency for MPO -463A was found to be 8.2% for cases and 10.5% for controls. The age, sex, smoking and drinking status adjusted odds ratio for all subjects for MPO -463 GG/GA as compared to the AA was 0.61 (95% CI: 0.28-1.32). The adjusted odds ratio for the GG/GA genotype was significantly low (0.15; 0.03-0.76, P=0.022) for those aged 61 years or older who had a significantly higher odds ratio for smoking than younger subjects. No difference was observed in disease risk when prevalent and incident cases were compared. Although there are limitations for interpretation of this study because of prevalent case-control study and partial statistical significance, these results suggest that MPO -463 A allele reduce the risk of esophageal cancer.

Smoking habit and interleukin lB C-31T polymorphism.

Recent studies suggest that smoking habit may relate to genetic traits. This study examines the association with a polymorphism (C-31T) of interleukin 1B (IL-1B), which encodes IL-1beta, a multifunctional pro-inflammatory cytokine. Since the T allele makes a TATA box, the allele is thought to be responsible for a higher potency of IL-1B expression, indicating that individuals harboring the T allele are prone to inflammation. The study subjects were two different populations; 241 non-cancer outpatients (118 males and 123 females) at a cancer hospital and 462 examinees (127 males and 335 females) of a health checkup program provided by a local government. Current smokers were 36.4% for the male outpatients, 9.8% for the female outpatients, 38.6% for the male examinees, and 5.6% for the female examinees. The sex-age-adjusted odds ratios of current smokers were calculated for the genotypes with the T allele relative to the CC genotype by an unconditional logistic model. The estimate was 0.45 (95% confidence interval, 0.21-0.97) for the outpatients, and 0.83 (0.42-1.61) for the examinees. Although not significant for the examinees, the observed associations suggest that this polymorphism may influence smoking behavior through an inflammatory response of the respiratory tract to cigarette smoke.

[Development and evaluation of a QOL questionnaire for elderly subject living in a community].

A comprehensive, basic and simple QOL questionnaire for elderly subjects living in a community was developed, and its validity and reliability were examined. The subjects were 2944 individuals of 65 years or older living in 5 areas of metropolitan Tokyo and in a town of Aichi Prefecture. The QOL questionnaire with 19 questions was developed based on the component of QOL by Lawton and concept of QOL by Koyano. The questionnaire consisted of 6 subscales (daily activity, satisfaction with health, satisfaction with human support, satisfaction with economic state, symptom of depression and positive mental attitude). Factor analysis revealed that the 19 questions could be clearly separated into 6 components in Tokyo and Aichi districts with total variances of 70.8% and 78.4%, respectively. Scores of daily activity and positive mental attitude were significantly lower with older subjects in both men and women. However, scores for other subscales did not differ with age. Primary factors which are considered to affect QOL were compared with the 6 QOL subscales of this study. Being an outpatient had a significant relation to daily activity and satisfaction with health, presence of a spouse to satisfaction with human support, depressive state, positive mental attitude and possession of ones own room to satisfaction with economical state, and belief in religion to positive mental attitude. The results suggest that the present questionnaire include the basic components necessary for evaluation of QOL in elderly subjects living in a community. Further research is required to examine the validity of this questionnaire with correction of questions.

Gene-environment interaction between an aldehyde dehydrogenase-2 (ALDH2) polymorphism and alcohol consumption for the risk of esophageal cancer.

Aldehyde dehydrogenase-2 (ALDH2) degrades acetaldehyde metabolized from ethanol. Its encoding gene ALDH2 has a functional polymorphism: ALDH2 Glu487LYS: An association between this polymorphism and esophageal cancer among alcoholics has been reported. To further evaluate the gene-environment interaction, a hospital-based case-control study was conducted. Cases were 102 patients with histologically confirmed esophageal cancer and controls were 241 non-cancer outpatients of Aichi Cancer Center. ALDH2 genotypes were examined by a PCR-CTPP method developed in our laboratory, which does not require a digestion stage. Logistic regression analysis was employed for estimation of relative risk and gene-environment interaction. The allele frequency for ALDH2 Lys487 was 0.28, consistent with previous reports. The age, sex, smoking and drinking status adjusted odds ratio for the ALDH2 Glu/Lys and Lys/Lys genotypes as compared with the Glu/Glu genotype was 3.43 (95% CI 1.74-6.75). The odds ratio for heavy drinking was 49.6 (14.5-169.4) among Lys487 carriers and 7.84 (2.77-22.2) for the Glu/Glu genotype. The gene-environment interaction between alcohol drinking and the ALDH2 Lys487 allele was 6.84 (2.39-19.6), whereas no significant interaction was obtained with smoking status. Although limited because of its prevalent case-control design, our study revealed a strong gene-environment interaction between ALDH2 polymorphism and heavy alcohol consumption. Taking the observed high risk of esophageal cancer in association with the ALDH2 Lys487 allele into consideration, reducing alcohol intake may be most protective among Lys487 allele carriers of this polymorphism.

Dietary factors and lung cancer risk in Japanese: with special reference to fish consumption and adenocarcinomas.

To investigate risk modification for lung cancer with diet in Japanese, we conducted a hospital-based case-control study and evaluated variation in influence with the histological type. We recruited 367 male and 240 female cases with adenocarcinomas, and 381 male and 57 female cases with squamous cell and small cell carcinomas. Controls comprised 2964 male and 1189 female cancer-free outpatients matched for sex and age with the cases. Odds ratios (ORs) and their 95% confidence intervals (CIs) for lung cancer were calculated with adjustment for potential confounding factors, using an unconditional logistic model. We found decreased ORs for adenocarcinomas in both males (OR = 0.51, 95% CI 0.31-0.84) and females (OR = 0.48, 95% CI 0.24-0.94) who consumed cooked/raw fish, but not dried/salted fish at the highest quartile frequency, compared with the lowest. Soybean curd consumption was associated with a decreased OR for female adenocarcinomas. Decreased ORs for squamous cell and small cell carcinomas were observed in males with frequent consumption of raw and green vegetables, fruit and milk, but consumption of carrot, pumpkin, egg and coffee was associated with increased ORs. This study suggests cooked/raw fish consumption lowers the risk of adenocarcinoma of the lung in Japanese.

Subsite-specific risk factors for hypopharyngeal and esophageal cancer (Japan).

OBJECTIVES: To clarify subsite-specific risk factors for hypopharyngeal and esophageal cancers (HC and EC), we concluded a hospital-based case-referent study in Nagoya, Japan. METHODS: Subjects comprised 346 male cases with cancer of the hypopharynx (n = 62) or esophagus (upper [U-EC] 53, middle [M-EC] 159, lower [L-EC] 72), and 11,936 male referents free from cancer among first-visit outpatients aged 40-79 years in 1988-1997. Of histological confirmed cases, 93% comprised squamous cell carcinoma. Odds ratios (ORs) were estimated by a logistic regression model with adjustment for potential confounding factors. RESULTS: Cigarette smoking increased the OR for M-EC, and alcohol drinking elevated the ORs for all subsites. The trend of ORs for combined cases of M- and L-EC tended to increase with number of cigarettes (p = 0.056), and a decreasing trend of the ORs was found with years after quitting smoking (p = 0.006). The ORs for smoking with drinking were multiplicatively greater than those for smoking or drinking in combined cases of HC and EC. In contrast, daily raw vegetable consumption lowered the ORs for all subsites. CONCLUSIONS: This study suggests that the magnitude of risk with smoking is stronger for M-EC within the esophagus, and drinking increases the risk at any subsite.