Adverse health effects of asbestos: solving mysteries regarding asbestos carcinogenicity based on follow-up survey of a Chinese factory

The present review summarizes the results of several follow-up studies assessing an asbestos product manufacturing plant in Chongqing, China, and discusses three controversial issues related to the carcinogenicity of asbestos. The first issue is the amphibole hypothesis, which asserts that the carcinogenicity of asbestos is limited to amphiboles, such as crocidolite, but not serpentines, such as chrysotile. However, considering the possible multiple component of asbestos carcinogenicity in the presence of tobacco smoke or other carcinogens, chrysotile cannot be regarded as non-carcinogenic. Additionally, in a practical sense, it is not possible to assume "pure" chrysotile due to its ubiquitous contamination with tremolite, which is a type of amphibole. Thus, as the International Agency for Research on Cancer (IARC) assessed, all forms of asbestos including chrysotile should be regarded carcinogenic to humans (Group 1). The second issue is the chrysotile/tremolite paradox, which is a phenomenon involving predominant levels of tremolite in the lung tissues of individuals who worked in locations with negligible levels of tremolite due to the exclusive use of chrysotile. Four possible mechanisms to explain this paradox have been proposed but this phenomenon does not support the claim that amphibole is inert. The final issue discussed is the textile mystery, i.e., the higher incidence of cancer in asbestos textile plants compared to asbestos mines where the same asbestos was produced and the exposure levels were comparable. This phenomenon was first reported in North America followed by UK and then in the present observations from China. Previously, levels of fiber exposure were calculated using a universal converting coefficient to estimate the mass concentration versus fiber concentration. However, parallel measurements of fiber and mass concentrations in the workplace and exposed air indicated that there are wide variations in the fiber/mass ratio, which unjustifies the universal conversion. It is possible that contamination by airborne non-fibrous particles in mines with mass fiber conversion led to the overestimation of fiber concentrations and resulted in the textile mystery. Although the use and manufacturing of asbestos has been banned in Japan, more than 10 million tons of asbestos had been imported and the majority remains in existing buildings. Thus, efforts to control asbestos exposure should be continued.

Characteristics of second-year residents intending to become a primary care physicians / 日本プライマリ・ケア連合学会誌

<b>Purpose</b> : To examine the characteristics of second-year residents intending to become primary care physicians.<br><b>Methods</b> : Using a self-administered questionnaire, we surveyed 7344 second-year residents in March, 2006. Of the 4167 responders (response rate 56.7%), the 3838 who answered that they intended to make a career choice of being clinical practitioners were taken as subjects for analysis. The odds ratios (OR) for the intention of being a primary care physician was calculated, together with the 95% confidence interval (95% CI), using logistic regression models (primary care physicians intended=1 vs. specialist intended=0) <br><b>Results</b> : In total, 56% of the residents affirmed an interest in becoming primary care physicians. Multiple stepwise logistic models showed that residents intending to become primary care physicians planned to open their own clinics in the future (OR 1.44, 95% CI : 1.20-1.73), did not wish to obtain doctor of medical science (DMSc) degrees (OR 1.29, 95% CI : 1.07-1.55), and were more likely to choose internal medicine (OR 1.44, 95% CI : 1.07-1.94).<br><b>Conclusion</b> : This study demonstrated that second-year residents who aimed to be primary care physicians were associated with more interest in opening private clinics for their future practice, preferably in the field of internal medicine, and with less interest in earning DMSc degrees.

The effects of marriage and child–bearing on career satisfaction among female physicians / 医学教育

The number of female physicians is increasing. In Japan, marriage and child–bearing have been considered barriers preventing female physicians from working continuously. This study investigated the effects of marriage and child–bearing on career satisfaction among female physicians.<br>1)We surveyed the alumni of two private medical schools (University A: n=646; University B: n=316). The response rate was 38% for University A and 71% for University B.<br>2)When the subjects were asked if they were satisfied that they had chosen a career as a physician, 85%(n=400) answered that they were satisfied.<br>3)In total, 348 female physicians (74%) were married, and of them, 280 (80%) had experienced childbirth, and 259 (77%) were married to physicians.<br>4)Factors that significantly and positively affected career satisfaction were marriage for all female physicians and child–bearing for married female physicians.<br>5)The results of this study suggest that marriage and child–bearing, rather than being obstacles to career development, have positive effects on the career satisfaction of female physicians.

Cancer mortality and asbestosis among workers in an asbestos plant in Chongqing, China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate whether asbestosis is a risk factor for mortality of lung cancer.</p><p><b>METHODS</b>A fixed cohort study was established in an asbestos plant in Chongqing, China, and followed up for 30 years from the beginning of 1972. Basic personal information on life state, cause of death, and diagnosis of asbestosis was collected. Multiple logistic regressions were applied to analyze risk factors.</p><p><b>RESULTS</b>During the 30-year follow-up, 584 male workers constituting a total of 14,664 person-years were monitored and data were analyzed. Among them, 203 (34.8%) died and the mortality rate was 13.8 per 1000 person-years, cancer accounting for 37.4%. Excess risks were observed for lung cancer (OR = 3.72) and nonmalignant respiratory diseases (OR = 2.73) among workers with asbestosis. High-exposure level was another risk factor for lung cancer (OR = 3.20). Workers with category II of asbestosis demonstrated a higher OR of both lung cancer and nonmalignant respiratory diseases than those with category I of asbestosis.</p><p><b>CONCLUSION</b>High asbestos exposure level and asbestosis were the risk factors for death of lung cancer and nonmalignant respiratory diseases. Asbestosis is an independent risk factor for lung cancer among Chinese workers exposed to chrysotile, the risk increases with the increasing profusion of opacities of lung.</p>

Competition or complement: relationship between judo therapists and physicians for elderly patients with musculoskeletal disease

<p><b>OBJECTIVES</b>Among the complementary and alternative medical services available in Japan, only judo therapists are covered under the national health-insurance program without a referral from a physician. Many orthopedists claim that judo therapists deprive them of potential patients. If such competition exists, fewer patients would be expected to visit orthopedists in areas where many patients visit judo therapists. Therefore, we examined the correlation between the number of patients visiting judo therapists and those visiting physicians for musculoskeletal diseases.</p><p><b>METHODS</b>In a cross-sectional study covering each prefecture in Japan (n = 47), we obtained figures for the numbers of judo therapist facilities and elderly patients (over 70 years old) who visited them and the numbers of orthopedists and patients who visited physicians for musculoskeletal diseases. Correlations between the numbers of practitioners per 100,000 population and the numbers of their patients per 100,000 population were examined by prefecture.</p><p><b>RESULTS</b>There were positive correlations between the numbers of judo therapist facilities and elderly patients who visited them (r = 0.72, P < 0.01, n = 47), and between the numbers of orthopedists and elderly patients who visited physicians for musculoskeletal diseases (r = 0.32, P = 0.03). However, there was no significant correlation between the numbers of elderly patients who visited judo therapist facilities and those who visited physicians (r = 0.06, P = 0.68) for musculoskeletal diseases.</p><p><b>CONCLUSIONS</b>This study did not find a negative correlation between the numbers of patients visiting judo therapists and patients visiting physicians for musculoskeletal diseases. Thus, these results do not support the orthopedists' claim that the two services compete for patients.</p>

Development of a questionnaire to assess 'Hie' symptoms using an evidence-based analysis

<p><b>OBJECTIVES</b>Certain symptoms and signs are culturally specific. 'Hie' (chill sensation) is a major symptom experienced by Japanese people; however, it is not easily understood by Westerners. Although Hie is not life-threatening, it greatly hampers the quality of life in sufferers. To develop a remedy for Hie, valid and reliable measures are required. This is the first study aimed at developing a standardized questionnaire to quantitatively measure Hie symptom.</p><p><b>METHODS</b>This was a cross-sectional study. To identify question items, we conducted a literature search using published books that mention Hie and related symptoms. The first draft of the questionnaire was prepared by selecting 31 items, including three empirically used items, using the Delphi method. A total of 744 Japanese volunteers completed the draft questionnaire. Simple correlation and factor analyses were performed to select items for the final version of Hie questionnaire and for evaluating its test-retest reliability.</p><p><b>RESULTS</b>The following ten question items were ultimately selected: feeling a breeze, shivery feeling, tolerance, sensitivity to cold, Hie-like sensation in an airplane, dislike of air conditioning, use of gloves, use of an electric blanket, use of heavy clothing and need for heating devices. Of the ten Hie-related question items, five pertained to physical symptoms and the other five to daily behaviours. The internal consistency of the ten-item questionnaire was high, with a Cronbach's alpha of 0.85. The test-retest reliability of the questionnaire was preserved by the paired two-tailed t test.</p><p><b>CONCLUSIONS</b>A new questionnaire was developed to evaluate the subjective symptom of Hie. This questionnaire demonstrated sufficient reliability and could be used as a tool to assess this symptom.</p>

Medical Education from the Perspectives of Medical Student with a Hearing Disability / 医学教育

1) Persons with hearing disabilities have been allowed to obtain medical licenses in Japan since 2002, and a medical student with a hearing disability has been receiving medical training at Teikyo University School of Medicine.<BR>2) Despite their best efforts, the student's classmates and instructors often did not recognize or understand his disabilities during medical training.<BR>3) Mutual understanding and support of team members are essential for medical students with hearing disabilities to become physicians. To this end, financial support from public institutions and other types of social support are also need

Training in End-of-life Care as an Elective Program for Medical Students / 医学教育

Bioethics and palliative care have rarely been taught systematically in Japanese medical schools, and methods for teaching them have not been established. This report is based on a program to teach end-of-life care as part of public health education for fifth-year students at Teikyo University School of Medicine. Medical students participated in an elective program for nursing students in end-of-life care, visited terminally ill patients, and made care plans. Through this experience, students came to understand the purpose of terminal care and became aware of the importance of mental support to patients and teamwork with co-medical staff. Having the opportunity to contemplate human death before starting clinical practice helps students acquire behaviors appropriate for physicians.