Increased risk of thyroid cancer in female residents nearby nuclear power plants in Korea: was it due to detection bias?

BACKGROUND: The Korea Radiation Effect & Epidemiology Cohort METHODS: Using the KREEC-R raw data, we calculated age standardized rates (ASRs) of female thyroid cancer and re-analyzed the results of survey on the use of medical services. We also marked the administrative districts of residents who received the Radiation Health Research Institute (RHRI) health examinations and those in which thyroid cancer case occurred as per the Chonnam National University Research Institute of Medical Sciences (RIMS) final report on maps where the locations of NPPs and 5 km-radii around them were also indicated. And we compared the incidence rates of Radiation-induced cancer measured between the first period when RHRI health examinations were not yet implemented, and the second period when the RHRI health examinations were implemented. RESULTS: The ASR for the far-distance group, which comprised residents living in areas outside the 30 km radius of the NPPs, increased rapidly after 2000; however, that of the exposed group, which comprised residents living within a 5 km radius of the NPPs, started to increase rapidly even before 1995. The frequencies of the use of medical services were significantly higher in the intermediate proximate group, which comprised residents living within a 5–30 km radius of the NPPs, than in the exposed group in women. In case of female thyroid cancer, the second period ASR was higher than the first period ASR, but in case of female liver cancer and female stomach cancer no significant difference were observed between the periods. On map, many administrative districts of residents who received RHRI health examinations and most administrative districts in which thyroid cancer case occurred on RIMS final report were outside 5 km-radii around NPPs. CONCLUSIONS: We could not find any evidence supporting the assertion that detection bias influenced the increased risks of female thyroid cancer observed in the exposed group of the KREEC-R study, as opposed to the control group.

The work-relatedness at a case of acute lymphoblastic leukemia in a radiation oncologist

BACKGROUND: Clinicians who perform radiation therapy (RT) are exposed to radiation, which may negatively affect their health. The present study reports a case of acute lymphoblastic leukemia in a healthcare provider who was exposed to radiation at work; we also present a literature review of this topic. CASE PRESENTATION: A 45-year-old patient, who had been a radiation oncologist and had been exposed to radiation while performing brachytherapy 10 years ago, complained of chest pain and was suspected of having leukemia based on the results of a blood test in an outpatient clinic. He was diagnosed with acute lymphoblastic leukemia, and subsequently underwent chemotherapy. However, the case died during treatment. Through epidemiological investigation, it was found that the case's cumulative exposure dose based on personal exposure and spatial dose measured during the work period was in the range of 6.08–12.15 mSv. CONCLUSIONS: Based on the following considerations, acute lymphoblastic leukemia was highly correlated with the level of radiation to which the case was exposed while performing brachytherapy on patients with cancer. Firstly, the latent period of acute lymphoblastic leukemia in the case closely matched the latency time reported in previous published studies (5–10 years). In addition, numerous studies have reported significantly higher relative risks of cancer among clinicians who perform RT compared with the general population. The case was also atypically exposed to radiation through his hands, despite wearing protective equipment. Lastly, the case's coworkers were also found to have been exposed to high levels of radiation. Investigation into the influence of radiation exposure through atypical routes during RT on the health of clinicians is recommended.

The effect of aircraft noise on sleep disturbance among the residents near a civilian airport: a cross-sectional study

BACKGROUND: Aircraft noise is a major environmental noise problem. This study was conducted in order to investigate the relationship between sleep disturbance and exposure to aircraft noise on the residents who are living near an airport. METHODS: There were 3308 residents (1403 in the high exposure group, 1428 in the low exposure group, and 477 in the non-exposure group) selected as the subjects for this study. The Insomnia severity Index (ISI) and Epworth Sleepiness Scale (ESS) questionnaires were used to evaluate sleep disturbance. RESULTS: The mean ISI and ESS scores were 6.9 ± 6.4 and 5.5 ± 3.7, respectively, and the average scores were significantly greater in the aircraft noise exposure group, as compared to the non-exposure group. The percentage of the abnormal subjects, which were classified according to the results of the ISI and ESS, was also significantly greater in the noise exposure group, as compared to the control group. The odd ratios for insomnia and daytime hypersomnia were approximately 3 times higher in the noise exposure group, as compared to the control group. CONCLUSIONS: The prevalence of insomnia and daytime hypersomnia was higher in the aircraft noise exposure group, as compared to the control group. Further study is deemed necessary in order to clarify the causal relationship.

Expression of Sfrp2 Is Increased in Catagen of Hair Follicles and Inhibits Keratinocyte Proliferation

BACKGROUND: Hair follicles undergo cycles of repeated growth and regression. The Wnt pathway plays an important role in the regeneration and differentiation of hair follicles. Sfrp2, a Wnt inhibitor, is involved in the developmental and disease processes of various cells and tissues by modulating the Wnt pathway. OBJECTIVE: The aim of this study was to understand the role of Sfrp2 in hair follicles through investigation of the Sfrp2 expression pattern in the skin and its effect on keratinocytes. METHODS: We investigated Sfrp2 mRNA expression and the expression of the wnt target genes, Ccnd1 and C-myc, at various mouse hair follicle developmental stages using Real-time polymerase chain reaction. We also investigated the effect of SFRP2 on the proliferation and differentiation of mouse keratinocyte cells by adding SFRP2 protein or overexpressing Sfrp2 using an in vitro culture system. RESULTS: Sfrp2 expression peaked in the catagen phase and remained high until telogen, and then declined at the beginning of the next anagen. An inverse relationship to Sfrp2 expression was found for the expression of the Wnt target genes, C-myc and Ccnd1. In addition, we also observed inhibited proliferation of mouse keratinocytes in the presence of SFRP2. CONCLUSION: These results suggest that Sfrp2 may play a role in the catagen phase by inhibiting the proliferation of keratinocyte and functioning as a Wnt inhibitor in keratinocytes.

The Hairless Gene: A Putative Navigator of Hair Follicle Development

The Hairless (HR) gene regulates the expression of several target genes as a transcriptional corepressor of nuclear receptors. The hair follicle (HF), a small independent organ of the skin, resides in the epidermis and undergoes regenerative cycling for normal hair formation. HF development requires many genes and signaling pathways to function properly in time and space, one of them being the HR gene. Various mutations of the HR gene have been reported to cause the hair loss phenotype in rodents and humans. In recent studies, it has been suggested that the HR gene is a critical player in the regulation of the hair cycle and, thus, HF development. Furthermore, the HR gene is associated with the Wnt signaling pathway, which regulates roliferation and differentiation of cells and plays an essential role in hair and skin development. In this review, we summarize the mutations responsible for human hair disorders and discuss the roles of the HR gene in HF development.

Influence of No Smoking and Rehabilitation after Microscopic Discectomy in Lumbar Disc Herniation: A Minimum of 10-Years Follow Up / 대한척추외과학회지

STUDY DESIGN: A retrospective analysis study of the long term clinical results of microscopic discectomy. OBJECTIVES: To evaluate clinical outcome of microscopic lumbar discectomy at the 10 year postoperative follow up SUMMARY OF LITERATURE REVIEW: There have been frequent reports of short term follow up studies for microscopic lumbar discectomies, but in there have been few long term follow-up studies reported in the literature. (Please confirm the highlighted section; before it was incomplete, so I have tried to complete for you.) MATERIALS AND METHODS: A ten year follow-up study was possible in 40 out of the 101 patients diagnosed with a lumbar disc herniation and treated with a microscopic discectomy between January 1992 and December 1993. Recurrent HIVD (Define?), followed by a microscopic discectomy, was evaluated using Kim's criteria. Also, the effects of smok0ing prohibition and rehabilitation exercise programs on recurrence were investigated. RESULTS: Among the 101 patients having undergone an operation, 5 and 10 year follow ups were performed in 83 (82.2%) and 40 cases (39.6%), respectively. Loss to follow-up was mostly due to changes of address and in the contact-list. 33 cases (84.6%) showed more than fair recovery after 5 years, with 33 cases (82.5%) showing similar results after 10 years. Postoperative smoking prohibition and exercise programs for the prevention of a recurrence were carried out on 32 cases (80%), with 2 of these cases (6.3%) showing recurrence compared with 5 cases (62.5%) in the non-control group. CONCLUSION: Postoperative smoking prohibition and rehabilitation exercise programs were useful and are recommended for lumbar disc herniation patient following a microscopic discectomy. Also, early return of the patient to their previous work could decrease the potential recurrence rate.