The hearing protectors most often used in noisy workplaces are earplugs. The sound attenuation performance of earplugs depends in part on the user's skill and knowledge. This study sought to clarify whether individual training and self-practice based on a checklist can improve sound attenuation. Measurements were performed as follows: Ten subjects, including both men and women, were provided with semi-insert earplugs (E-A-R flex 350-1001) and wore them based only on the printed instructions of the product. Sound attenuation was measured from 125Hz to 8000Hz, in accordance with JIS T8161-1983. Intervention was provided through 5 minute individual training with oral and written instructions, followed by 10 minute self-practice each day for 7 days. Sound attenuation was then measured once again. The results indicated significantly improved attenuation, ranging from 7.7dB to 11.7dB, in all frequencies following training, confirming the effectiveness of the intervention. This is an easy and effective method for training workers in how to wear earplugs most effectively.

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In recent decades, Iran has had a steadily growing economy with an annual rate of 6% on average. The country's economy is dominantly influenced by oil and natural gas production and related industries like petrochemicals and fertilizers. There are two million job units and sixteen million employees. The occupational health and safety (OHS) system is mainly regulated by two bodies: the Ministry of Health and Medical Education, responsible for occupational health services and legislations; and the Ministry of Labour and Social Affairs, which undertakes the enactment and enforcement of occupational safety legal issues. Inspectorates in each ministry carry out regular health and safety monitoring according to the OHS legislations. The most common occupational health disorders are musculoskeletal problems, respiratory diseases, noise induced hearing loss, and occupational injuries. Because the OHS is a complex system with overlapping responsibilities among the co-responders, its improvement needs well-organized collaboration among Iranian universities, industries, and governmental agencies, and reliable basic data. The present study takes a glance at the situation and activities of the Iranian OHS system.

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Apocrine carcinoma is a rare variant of breast carcinoma, and accounts for 0.3 to 1.0% of all breast cancers. A 55-year-old Japanese female patient presented with a right breast tumor, which had been detected by mass-screening, and she was admitted to our hospital. The physical examination revealed an elastic hard lump in the upper lateral quadrant of the right breast. The tumor size was approximately 1.0cm in diameter, and the border was clear. There were no palpable axillary lymph nodes nor supraclavicular nodes. Fine-needle aspiration cytology revealed invasive ductal carcinoma. The patient underwent a partial resection of the right breast (breast conserving therapy) and a right axillary lymphadenectomy. Macroscopically, the resected specimen revealed a white tumor measuring 1.2×1.2×1.0cm. The TNM classification was diagnosed as T1cN0M0 stage Ⅰ. Histopathologically, the tumor revealed a proliferation of atypical epithelial cells with apocrine differentiation, arranged in a papillotubular or cribriform growth pattern with stromal invasion. The tumor cells showed irregular round-shaped nuclei often containing prominent nucleoli, and had particularly abundant eosinophilic granular cytoplasm. In the immunohistochemical analysis, these carcinoma cells were positive for Gross Cystic Disease Fluid Protein 15 and the androgen receptor, whereas they were negative for the estrogen and progesterone receptors. Immunohistochemical staining for Her2 using the HercepTest was found to be negative (score 0). Thus, the pathological diagnosis was apocrine carcinoma. There were no metastases in the axillary lymph nodes. The patient has had no recurrence in 8 years after surgery.

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Only a small number of aneurysms arising on the posterior communicating artery itself (true Pcom aneurysm) have been reported. We report two cases of ruptured true Pcom aneurysms with some characteristic features of true Pcom aneurysm. A 43 year old man suffering from subarachnoid hemorrhage (SAH) had an aneurysm arising on the fetal-type Pcom artery itself, and underwent surgery for clipping. Most of the aneurysm was buried in the temporal lobe, so retraction of the temporal lobe was mandatory. During the retraction, premature rupture was encountered. After tentative dome clipping and the control of bleeding, complete clipping was achieved. Another patient, a 71 year old woman presenting with consciousness disturbance due to SAH, had an aneurysm on the fetal-type Pcom artery itself, and underwent surgery for clipping. It has been generally considered that hemodynamic factor plays an important role in the formation, the growth, and the rupture of the cerebral aneurysm. This factor is especially significant in true Pcom aneurysm formation and rupture. According to the literature, a combination of fetal type Pcom and formation of the true Pcom aneurysm has been reported in most cases (81.8%). Most of the aneurysm can be buried in the temporal lobe, and the retraction of the temporal lobe during the dissection of the neck would be necessary, which causes premature rupture of the true Pcom aneurysm. In the surgery for a true Pcom aneurysm, we should be aware of possible premature rupture when temporal lobe retraction is necessary.

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A 37-year-old Japanese man presented with alopecia after being involved in a traffic accident. An immunohistochemical study of the biopsy specimen demonstrated that CD8⁺ T cells infiltrated into hair follicles with satellite cell necrosis of keratinocytes. Four weeks after his initial visit, he again had another traffic accident. Despite the treatment with oral prednisolone and a topical steroid, the alopecia became universalis. Treatment with systemic and topical steroids was continued, and 12 weeks later, white vellus hairs grew over the whole scalp. Intracytoplasmic study revealed that there was a positive correlation between the severity of the alopecia and the increase of interferon-γ producing Th1 cells or interleukin (IL)-17 producing Th17 cells, whereas the number of IL-4 expressing Th2 cells was inversely proportional to the extent of alopecia. The autoimmune hair loss might occur via the activation of T helper 1 (Th1) and Th17 cells.

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From 1998 to 2000, UOEH Hospital identified a problem with bronchoscopes which were contaminated with mycobacteria. While conducting research into the problem, we found an extensive amount of nontuberculous mycobacteria (NTM) in wet areas. In this study, we collected a total of 114 samples to screen wet areas such as drains and taps in our hospital and in standard residences. We used the Ziehl-Neelsen staining method and specific PCR for mycobacteria. As a result, mycobacteria were detected in 96% (27/28) of hospital samples and 40% (34/86) of standard residential samples. Next, we tried to isolate mycobacteria. Eleven isolates from hospital samples and 24 isolates in standard residential samples were isolated through cultivation. Seventeen isolates of Mycobacterium gordonae were isolated. Four isolates of M. avium were isolated exclusively in hospital samples. Three isolates of M. avium were resistant to 8 antimicrobial agents, including antituberculous agents. Two hospital isolates survived in phagocytes. Although 80% ethanol solution was effective in all 13 tested isolates, it was not effective in decontaminating the one drain we tested. After brushing the drain with 80% ethanol solution, mycobacteria were not detected for 3 months. This indicated to us that brushing with 80% ethanol solution was an effective procedure for eradicating mycobacteria.

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The hood performance of a local exhaust ventilation system is determined by the capture velocity and the air flow rate. The equation proposed by Dalla Valle has been widely used to speculate this relationship. However, Dalla Valle used different formulae for slot and plain opening (rectangular) hoods, and the calculated values near the boundary between the slot and plain opening by these formulae do not always match each other. In this study, we measured capture velocity of four hoods by changing the distance from the hood face for different aspect ratios. We also tried to develop an empirical formula to express a relationship that could be applied to both types of hoods. As a result, it was found that the relationship between air velocity in front of exterior hoods and air flow rate could be expressed as the sum of two exponential functions with distance. In addition, when the hood aspect ratio was less than 9 the values of the capture velocity calculated by the proposed equation were in good agreement with the experimental ones.

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Two major degradation systems exist in cells: the lysosome and proteasome. In the lysosome system, extracellular materials are degraded via endocytosis. Intracellular materials are degraded by autophagy, a cellular pathway crucial for various intracellular events. It has recently been demonstrated that autophagy is involved in the pathogenesis of various liver diseases. In hepatitis B or hepatitis C virus infection, autophagy is enhanced in hepatocytes. In hepatic steatosis, hepatocyte autophagy is inhibited. The expression of the autophagy protein is disrupted in hepatocellular carcinoma. I summarize recent advances in the study of the involvement of autophagy in various liver diseases. The regulation of autophagy in the liver may be a useful therapeutic strategy for various liver diseases.

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