Impact of neck posture and insulating stick use on neck disability in Korean line workers: a cross-sectional study

Background

Occupational neck disability is a prevalent issue, especially among line workers, who are often exposed to elevated levels of cervical ergonomic stress. The aim of this study was to investigate the impact of neck posture and insulating stick use on neck disability in a specific occupational group in Korea.

Methods

This cross-sectional study was conducted among 483 line workers in Gwangju and Jeonnam, Korea. Data were collected using the Neck Disability Index, Cervical Degenerative Index, and a structured questionnaire focusing on demographic and occupational factors. Logistic regression analysis was applied to determine the adjusted odds ratio (OR) and 95% confidence interval (CI) for neck posture and factors related to neck disability.

Results

Neck disability prevalence was 17.2% among the participants. Multivariate logistic regression analysis showed that factors related to neck disability included age over 60 years (adjusted OR: 3.08; 95% CI: 1.63-5.83), depression (adjusted OR: 8.33; 95% CI: 3.85-18.00), a history of cervical trauma (adjusted OR: 2.13; 95% CI: 1.04-4.40), and radiological degenerative changes in the cervical spine (adjusted OR: 2.33; 95% CI: 1.26-4.33). In particular, the adjusted OR of neck disability among live-line workers was 2.10 (95% CI: 1.12-3.92) when compared with support workers (model 1). Other analysis models showed that use of insulating sticks for more than 10 hours per week (adjusted OR: 2.46; 95% CI: 1.32-4.61) and higher neck extension (adjusted OR: 2.98; 95% CI: 1.14-3.46) were significant work-related risk factors (model 2,3).

Conclusions

Neck posture, age, depression, cervical trauma history, degenerative changes in the cervical spine, and use of insulating sticks are significant risk factors for neck disability among line workers in Korea. These findings highlight the need to improve the working environment and reduce the burden of cervical ergonomic stress among line workers.

Work-Related Risk Factors of Knee Meniscal Tears in Korean Farmers: A Cross-Sectional Study

Background

Meniscal tears are among the major risk factors for knee osteoarthritis progression. This study aimed to investigate the relationship between meniscal tears and work-related factors in the farming occupation.

Methods

The participants included 486 farmers (238 men and 248 women), aged 40–69 years, who were among the 550 farmers registered in the Korea Farmer's Knee Cohort (KFKC). Data such as those on gender, age, body mass index (BMI), mechanical axis, cumulative heavy-lifting working time (CLWT), cumulative squatting working time (CSWT), and previous knee injury history were collected from the questionnaire, along with whole leg radiographic findings. Two radiologists assessed the magnetic resonance images of both knees to confirm the presence of meniscal tears. The factors related to meniscal tears were analyzed by multiple logistic regression.

Results

A total of 54.5% of the farmers (48.7% of men and 60.1% of women) had meniscal tears. These tears were associated with gender, age, and BMI. We also identified an association between meniscal tears and CSWT, an especially important factor in farming [10,000–19,999 working hours, odds ratio = 2.16, 95% confidence interval (CI): 1.14-4.07, ≥20,000 working hours, odds ratio = 2.35, 1.45-3.80]. However, mechanical axis, knee injury history, and CLWT were not significantly related to meniscal tears.

Conclusion

This study's findings show that squatting for long periods, as an occupational factor, is related to meniscal tears.

Effects of work-related factors on self-reported smoking among female workers in call centers: a cross-sectional study

Objectives

This study conducted to investigate work-related factors in relation to smoking among women working in call centers in Gwangju, South Korea.

Methods

From 56 call centers (7320 employees), we selected 10 and conducted a survey using a structured questionnaire by randomly selecting 10% of workers from each center. A total of 387 subjects participated in this survey We analyzed for 375 respondents, after excluding men and those with missing responses. We analyzed the relationships of work-related factors such as emotional labor, workplace violence, employment type, annual salary, working hours, employment period with smoking, using multiple logistic regression analysis. Emotional labor and workplace violence were measured using the Korean Emotional Labor Scale (K-ELS) and Korean Workplace Violence Scale (K-WVS).

Results

The prevalence of current smoking among call center female workers was 13.6%. Univariate analysis showed that “Emotional disharmony and hurt”, “Experience of psychological and sexual violence from supervisors and co-workers” among items of K-ELS and K-WVS, working hours, annual salary correlated with smoking. After adjusting for emotional labor, workplace violence, employment type, annual salary, working hours, employment period, and age, only working hours show a significant association with smoking. Women who worked 40–49 h had 3.50 times (95% CI = 1.04–11.80) and worked more than 50 h had 8.68 times (95% CI = 1.89–39.78) greater odds of smoking as compared with women who worked less than 40 h.

Conclusions

Smoking was associated with working hours among female workers in call center. However, emotional labor and workplace violence did not show significant relationships with smoking.

Evaluation of the prevalence of musculoskeletal symptoms, presumptive diagnosis, medical care use, and sick leave among female school meal service workers

Background

Most of the school meal service workers in Korea are middle-aged individuals. They have high workload, which increases their incidence of musculoskeletal disorders. This study aimed to evaluate the prevalence and risk factors of subjective musculoskeletal symptoms, presumptive diagnosis, medical care use, and sick leave among female school meal workers.

Methods

We analyzed the results of musculoskeletal disease screening of 1581 female school meal workers. The screening consisted of self-administered questionnaire, history taking by occupational physicians, and physical examination. The prevalence of subjective musculoskeletal symptoms, presumptive diagnosis after initial examination by occupational physicians, use of medical care for more than 7 days, and sick leave due to musculoskeletal diseases during the past year were evaluated in this study. The relative risk of four outcome indicators of musculoskeletal disorders was compared with respect to potential factors, such as age, subjective physical loading, present illness, injury experience, and type of school, using log-binomial regression.

Results

The prevalence of subjective musculoskeletal symptom was 79.6%; presumptive diagnosis, 47.6%; hospital visits over 7 days, 36.4%; and sick leave, 7.3%. The relative risk of musculoskeletal symptoms by age (≥50 years vs < 50 years) was 1.04 (95% confidence interval (CI): 1.00–1.09); presumptive diagnosis of musculoskeletal disease, 1.17 (95% CI: 1.06–1.30); hospital visits over 7 days, 1.26 (95% CI: 0.85–1.85); and sick leave, 1.17 (95% CI: 1.02–1.34). The relative risk of musculoskeletal symptoms due to subjective physical loading (very hard vs low) was 1.45 (95% CI: 1.33–1.58); presumptive diagnosis, 2.92 (95% CI: 2.25); hospital visits over 7 days, 1.91 (95% CI: 1.02–3.59); and sick leave, 2.11 (95% CI: 1.63–2.74).

Conclusions

Subjective physical loading was a more important factor in musculoskeletal disorders than the age of female school meal workers.

Systemic sclerosis due to crystalline silica exposure among jewelry workers in Korea: two case reports

Background

Occupational exposure to crystalline silica is a potential risk factor for various systemic autoimmune diseases including systemic sclerosis. The etiology of systemic sclerosis is not conclusively known, but there are epidemiological studies that show the relationship between exposure to crystalline silica and risk of systemic sclerosis. Here we report, for the first time, two cases of crystalline silica-related systemic sclerosis in patients who worked in crystal processing in the jewelry-manufacturing field.

Case presentation

Case 1 is a 57-year-old man who had worked mainly in crystal processing for multiple jewelry-processing companies for 17 years, since the age of 15 years. He contracted tuberculosis at the age of 25 years and showed Raynaud’s phenomenon of both the hands and feet at age 32 years. Digital cyanosis and sclerosis developed at approximately age 41 years. The patient was diagnosed with systemic sclerosis at age 48 years.

Case 2 is a 52-year-old man who worked in crystal processing for various jewelry-processing companies for 7 years, since the age of 23 years. He first showed signs of cyanosis in the third and fourth digits of both hands at age 32 years, was diagnosed with Raynaud’s syndrome at age 37 years, and was diagnosed with systemic sclerosis at age 38 years.

Crystal processing is a detailed process that involves slabbing and trimming the selected amethyst and quartz crystals, which requires close proximity of the worker’s face with the target area. In the 1980s and 1990s, the working hours were 12 h per day, and the working environment involved 15 workers crowded into a small, 70-m² space with poor ventilation.

Conclusion

Two workers who processed crystals with a maximum crystalline silica content of 56.66% developed systemic sclerosis. Considering the epidemiological and experimental evidence, exposure to crystalline silica dust was an important risk factor for systemic sclerosis. An active intervention is necessary to reduce exposure in similar exposure groups in the field of jewelry processing.

Cases of acute mercury poisoning by mercury vapor exposure during the demolition of a fluorescent lamp factory

Background

In 2015, workers dismantling a fluorescent lamp factory in Korea were affected by mercury poisoning from exposure to mercury vapor.

Case presentation

Eighteen out of the 21 workers who participated in the demolition project presented with symptoms of poisoning and, of these, 10 had persistent symptoms even at 18 months after the initial exposure to mercury vapor. Early symptoms of 18 workers included a general skin rash, pruritus, myalgia, sleep disturbance, and cough and sputum production. Following alleviation of these initial symptoms, late symptoms, such as easy fatigue, insomnia, bad dreams, and anxiety disorder, began to manifest in 10 out of 18 patients. Seven workers underwent psychiatric care owing to sleep disturbance, anxiety disorder, and depression, and three workers underwent dermatologic treatment for hyperpigmentation, erythematous skin eruption, and chloracne-like skin lesions. Furthermore, three workers developed a coarse jerky movement, two had swan neck deformity of the fingers, and two received care at an anesthesiology clinic for paresthesia, such as burning sensation, cold sensation, and pain. Two workers underwent urologic treatment for dysfunction of the urologic system and impotence. However, symptomatic treatment did not result in satisfactory relief of these symptoms.

Conclusion

Awareness of the perils of mercury and prevention of mercury exposure are critical for preventing health hazards caused by mercury vapor. Chelation therapy should be performed promptly following mercury poisoning to minimize damage.

Air pollution and urinary n-acetyl-B-glucosaminidase levels in residents living near a cement plant

Background

To identify adverse renal effects due to air pollution derived from a cement plant in Korea. Urinary n-acetyl-B-glucosaminidase (U-NAG) levels in residents living near a cement plant were compared to those in a group who lived farther away from the plant.

Methods

From June to August 2013 and from August to November 2014, laboratory tests for U-NAG and heavy metal were conducted on 547 study participants. Based on the level of air pollution exposure, subjects were divided into the “less exposed group,” (LEG) which consisted of 66 persons who lived more than 5 km away from the cement plant, the “more exposed group from the rural area” (MEG-R), which consisted of 272 persons, and the “more exposed group from downtown area” (MEG-D), which consisted of 209 persons who lived within a 1 km radius of the cement plant. U-NAG levels >5.67 U/L were defined as “higher U-NAG” levels. We compared the prevalence of higher U-NAG levels and estimated the adjusted odds ratio (OR) by air pollution exposure using a chi-square test and multiple logistic regression analysis. Further, we estimated the interaction between air pollution exposure and heavy metal exposure in renal toxicity.

Results

The OR of higher U-NAG levels by MEG-D and MEG-R compared to LEG was 2.13 (95 % CI 0.86–4.96) and 4.79 (95 CI 1.65–10.01), respectively. Urinary cadmium (U-Cd), urinary mercury (U-Hg), age, occupation, hypertension, and diabetes had a significant association with higher U-NAG levels. However, blood lead (B-Pb), sex, and smoking were not associated with higher U-NAG. Especially, concurrent exposure to heavy metals (U-Hg or/and U-Cd) and air pollution had an additive adverse effect. In the group with both 4^th quartile heavy metal exposure (U-Cd or/and U-Hg) and air pollution exposure, the OR in MEG-R and MEG-D was 6.49 (95 % 1.42–29.65) and 8.12 (95 % CI 1.74–37.92), respectively, after adjustment for age, occupation, hypertension, diabetes.

Conclusions

U-NAG levels seem to be affected by air pollution exposure as well as age, hypertension, diabetes, and even low levels of cadmium and low levels of mercury. Moreover, concurrent exposure to heavy metals and air pollution can have additive cytotoxic renal effects.

Antinociceptive Effects of Botulinum Toxin Type A on Trigeminal Neuropathic Pain

Previous studies have demonstrated that botulinum toxin type A (BoNT-A) attenuates orofacial nociception. However, there has been no evidence of the participation of the voltage-gated sodium channels (Navs) in the antinociceptive mechanisms of BoNT-A. This study investigated the cellular mechanisms underlying the antinociceptive effects of BoNT-A in a male Sprague-Dawley rat model of trigeminal neuropathic pain produced by malpositioned dental implants. The left mandibular second molar was extracted under anesthesia, followed by a miniature dental implant placement to induce injury to the inferior alveolar nerve. Mechanical allodynia was monitored after subcutaneous injection of BoNT-A at 3, 7, or 12 d after malpositioned dental implant surgery. Subcutaneous injections of 1 or 3 U/kg of BoNT-A on postoperative day 3 significantly attenuated mechanical allodynia, although 0.3 U/kg of BoNT-A did not affect the air-puff threshold. A single injection of 3 U/kg of BoNT-A produced prolonged antiallodynic effects over the entire experimental period. Treatment with BoNT-A on postoperative days 7 and 12, when pain had already been established, also produced prolonged antiallodynic effects. Double treatments with 1 U/kg of BoNT-A produced prolonged, more antiallodynic effects as compared with single treatments. Subcutaneous administration of 3 U/kg of BoNT-A significantly inhibited the upregulation of Nav isoform 1.7 (Nav1.7) expression in the trigeminal ganglion in the nerve-injured animals. These results suggest that antinociceptive effects of BoNT-A are mediated by an inhibition of upregulated Nav1.7 expression in the trigeminal ganglion. BoNT-A is therefore a potential new therapeutic agent for chronic pain control, including neuropathic pain.

Distal airways are protected from goblet cell metaplasia by diminished expression of IL-13 signalling components

BACKGROUND

Increased mucus production is a critical factor impairing lung function in patients suffering from bronchial asthma, the most common chronic inflammatory lung disease worldwide.

OBJECTIVE

This study aimed at investigating whether goblet cell (GC) metaplasia and mucus production are differentially regulated in proximal and distal airways.

METHODS

Female Balb/c mice were sensitized to ovalbumin (OVA) and challenged with an OVA-aerosol on two consecutive days for 1 week (acute) or 12 weeks (chronic). Real-time RT-PCR analysis was applied on microdissected airways.

RESULTS

In acutely and chronically OVA-challenged mice, GC metaplasia and mucus production were observed in proximal but not in distal airways. In contrast, inflammation reflected by the infiltration of eosinophils and expression of the TH2-type cytokines IL-4 and IL-13 was increased in both proximal and distal airways. Abundance of IL-13Rα1 was lower in distal airways of healthy control mice. Under acute and chronic OVA-exposure, activation of IL-13Rα1-dependent signalling cascade, reflected by Spdef and Foxo3A transcription factors, was attenuated in distal compared to proximal airways.

CONCLUSION AND CLINICAL RELEVANCE

These data indicate that distal airways might be less sensitive to IL-13-induced GC metaplasia and mucus production through lower expression of IL-13Rα1 and attenuated activation of downstream signalling. This might represent a protective strategy to prevent mucus plugging of distal airways and thus impaired ventilation of attached alveoli.

Emphysema prevalence related air pollution caused by a cement plant

Background

To identify adverse pulmonary health effects due to air pollution derived from a cement plant in Korea. The emphysema prevalence in residents around a cement plant was compared to that in the group who live far away from the plant by chest films (PA and lateral view) and high-resolution computed tomography (HRCT) lung images.

Methods

From June to August in 2013 and from August to November in 2014, chest films and HRCT scan were conducted on residents over the age of 40 who lived around a cement plant. The residents were divided into two groups; a “more exposed group (MEG)” which consisted of 1,046 people who lived within a 1 km radius and a “less exposed group (LEG)” which consisted of 317 people who lived more than 5 km away from the same plant. We compared the emphysema prevalence and estimated the OR of this between the MEG and the LEG by using a chi-square and logistic regression on chest films and HRCT.

Results

The emphysema prevalence was 9.1 % in the LEG, 14.3 % in the MEG on chest films and 11.4 %, 17.8 % on the HRCT, respectively. The OR of the emphysema prevalence in MEG was 2.92 (95 % CI 1.77-4.83) on the chest films, 2.56 (95 % CI 1.64–3.99) on the HRCT after sex, age, body mass index (BMI), smoking history, residency period and firewood used history were adjusted. The OR in the less than 29 pack-years smoking history was 1.66 (95 % CI 0.92–3.06) and in the more than 30 pack-years was 3.05 (95 % CI 1.68–5.52) on the chest films, and was 1.68 (95 % CI 0.98–2.90), 2.93 (95 % CI 1.72–4.98) on the HRCT, respectively.

Conclusion

The emphysema prevalence seems to be affected by the level of exposure to air pollution derived from the cement plant as well as sex, age, BMI, and smoking history in this study. Moreover, the OR of the case of the more exposed to the air pollution was similar to that of the case in smoking.

Clinical utility of routine laboratory testing to identify possible secondary causes in older men with osteoporosis: the Osteoporotic Fractures in Men (MrOS) Study

We investigated the value of routine laboratory testing for identifying underlying causes in older men diagnosed with osteoporosis. Most osteoporotic and nonosteoporotic men had ≥1 laboratory abnormality. Few individual laboratory abnormalities were more common in osteoporotic men. The benefit of routine laboratory testing in older osteoporotic men may be low.

INTRODUCTION

To evaluate the utility of recommended laboratory testing to identify secondary causes in older men with osteoporosis, we examined prevalence of laboratory abnormalities in older men with and without osteoporosis.

METHODS

One thousand five hundred seventy-two men aged ≥65 years in the Osteoporotic Fractures in Men study completed bone mineral density (BMD) testing and a battery of laboratory measures, including serum calcium, phosphorus, alkaline phosphatase, parathyroid hormone (PTH), thyroid-stimulating hormone (TSH), 25-OH vitamin D, total testosterone, spot urine calcium/creatinine ratio, spot urine albumin/creatinine ratio, creatinine-derived estimated glomerular filtration rate, 24-h urine calcium, and 24-h urine free cortisol. Using cross-sectional analyses, we calculated prevalence ratios (PRs) and 95 % confidence intervals (CI) for the association of any and specific laboratory abnormalities with osteoporosis and the number of men with osteoporosis needed to test to identify one additional laboratory abnormality compared to testing men without osteoporosis.

RESULTS

Approximately 60 % of men had ≥1 laboratory abnormality in both men with and without osteoporosis. Among individual tests, only vitamin D insufficiency (PR, 1.13; 95 % CI, 1.05-1.22) and high alkaline phosphatase (PR, 3.05; 95 % CI, 1.52-6.11) were more likely in men with osteoporosis. Hypercortisolism and hyperthyroidism were uncommon and not significantly more frequent in men with osteoporosis. No osteoporotic men had hypercalciuria.

CONCLUSIONS

Though most of these older men had ≥1 laboratory abnormality, few routinely recommended individual tests were more common in men with osteoporosis than in those without osteoporosis. Possibly excepting vitamin D and alkaline phosphatase, benefit of routine laboratory testing to identify possible secondary causes in older osteoporotic men appears low. Results may not be generalizable to younger men or to older men in whom history and exam findings raise clinical suspicion for a secondary cause of osteoporosis.

Injury to the blood-testis barrier after low-dose-rate chronic radiation exposure in mice

Exposure to ionising radiation induces male infertility, accompanied by increasing permeability of the blood-testis barrier. However, the effect on male fertility by low-dose-rate chronic radiation has not been investigated. In this study, the effects of low-dose-rate chronic radiation on male mice were investigated by measuring the levels of tight-junction-associated proteins (ZO-1 and occludin-1), Niemann-Pick disease type 2 protein (NPC-2) and antisperm antibody (AsAb) in serum. BALB/c mice were exposed to low-dose-rate radiation (3.49 mGy h(-1)) for total exposures of 0.02 (6 h), 0.17 (2 d) and 1.7 Gy (21 d). Based on histological examination, the diameter and epithelial depth of seminiferous tubules were significantly decreased in 1.7-Gy-irradiated mice. Compared with those of the non-irradiated group, 1.7-Gy-irradiated mice showed significantly decreased ZO-1, occludin-1 and NPC-2 protein levels, accompanied with increased serum AsAb levels. These results suggest potential blood-testis barrier injury and immune infertility in male mice exposed to low-dose-rate chronic radiation.

Ventilation impairment of residents around a cement plant

Objectives

To identify adverse health effects due to air pollution derived from a cement plant in Korea. The ventilation impairment in residents around a cement plant was compared to another group through a pulmonary function test (PFT).

Methods

From June to August of 2013, both a pre and post-bronchodilator PFT was conducted on a “more exposed group (MEG)” which consisted of 318 people who lived within a 1 km radius of a cement plant and a “less exposed group (LEG)” which consisted of 129 people who lived more than 5 km away from the same plant. The largest forced expiratory volume in a one second (FEV1) reading and a functional residual capacity (FVC) reading were recorded after examining the data from all of the usable curves that were agreed upon as valid by PFT experts of committee of National Institute of Environmental Research. The global initiative for chronic obstructive lung disease (GOLD) criteria for COPD, defined the FEV1/FVC ratio < 0.7 as the obstructive type, and the FEV1/FVC ratio ≧ 0.7 and FVC% predicted < 80% were as the restrictive type. The FVC% predicted value was estimated using Korean equation. We compared the proportion of lung function impairments between the MEG and the LEG by using a chi-square, and estimated the OR of obstructive and restrictive ventilation impairments by logistic regression.

Results

The obstructive type impairment proportion was 9.7% in the MEG, whereas it was 8.5% in the LEG. The restrictive type was 21.6% in the MEG which was more than the 12.4% of the LEG. The odds ratio (OR) of total ventilation impairment in the MEG was 2.63 (95% CI 1.50 ~ 4.61) compared to the LEG. The OR of obstructive type in the MEG was 1.60 (95% CI 0.70 ~ 3.65), the smoking history was 3.10 (CI 1.10 ~ 8.66) whereas OR of restrictive type in the MEG was 2.55 (95% CI 1.37 ~ 4.76), the smoking history was 0.75 (95% CI 0.35 ~ 1.60) after adjusting for sex and age. Level of exposure to particulate played a role in both types. However, it appeared to be a significant variable in restrictive type, while smoking history was also an important variable in obstructive type.

Conclusion

Although this study is a limited cross-section study with a small number of subjects, ventilation impairment rate is higher in the MEG. There might be a possibility that it is due to long-term exposure to particulate dust generated by the cement plant.

A unique role for p53 in the regulation of M2 macrophage polarization

P53 is critically important in preventing oncogenesis but its role in inflammation in general and in the function of inflammatory macrophages in particular is not clear. Here, we show that bone marrow-derived macrophages exhibit endogenous p53 activity, which is increased when macrophages are polarized to the M2 (alternatively activated macrophage) subtype. This leads to reduced expression of M2 genes. Nutlin-3a, which destabilizes the p53/MDM2 (mouse double minute 2 homolog) complex, promotes p53 activation and further downregulates M2 gene expression. In contrast, increased expression of M2 genes was apparent in M2-polarized macrophages from p53-deficient and p53 mutant mice. Furthermore, we show, in mice, that p53 also regulates M2 polarization in peritoneal macrophages from interleukin-4-challenged animals and that nutlin-3a retards the development of tolerance to Escherichia coli lipopolysaccharide. P53 acts via transcriptional repression of expression of c-Myc (v-myc avian myelocytomatosis viral oncogene homolog) gene by directly associating with its promoter. These data establish a role for the p53/MDM2/c-MYC axis as a physiological 'brake' to the M2 polarization process. This work reveals a hitherto unknown role for p53 in macrophages, provides further insight into the complexities of macrophage plasticity and raises the possibility that p53-activating drugs, many of which are currently being trialled clinically, may have unforeseen effects on macrophage function.

Giant cell tumor of upper thoracic spine

Giant cell tumor (GCT) of the spine is a rare benign tumor, but can be aggressive and can exhibit a high local recurrence rate. Furthermore, GCT of the upper thoracic spine may pose diagnostic and management difficulties. Here, we report a rare case of GCT of the upper thoracic spine with soft tissue extension to the spinal canal. The patient was managed by decompressive laminectomy and posterolateral fusion followed by an injection of polymethylmethacrylate into the vertebral lesion. The patient recovered clinically and showed radiological improvement after surgical treatment without tumor recurrence at his last follow-up of postoperative 7 years. We present this unusual case of GCT and include a review of the literature.

Cardiovascular disease risk of bus drivers in a city of Korea

Objective

To prevent the occurrence of CV events such as MI and stroke among professional drivers in Korea, bus drivers were compared to other occupations through the Framingham risk scoring system (FRS) or metabolic syndrome (MS) of cardiovascular disease (CVD) risk assessment methods.

Methods

In October 2012, a health examination survey was conducted for 443 male bus drivers in a big city. Their CVD risk factors were compared to those of a ‘total employed’ (A group) and ‘crafts and machine operators’ (B group) extracted from Fifth Korea National Health and Nutrition Examination Survey (KNHANES, 2010) data by using FRS and MS. We calculated proportions of the CVD risk factors distribution between bus drivers and the A, B groups by the bootstrapping method. The Odds ratio (OR) between CV event risk combining MS with CHD equivalent risk of FRS and occupational factors like shift patterns and professional driving duration/age ratios (PDAR) of bus drivers was calculated through multinominal logistic regression.

Results

The proportion of BMI ≥ 25 kg/m² was 53.9% and waist circumference ≥ 90cm was 40.9% among bus drivers. Hypertension and MS prevalence of bus drivers was 53.3%, 49.9% which is higher than 17.6%, 22.6% in the A group and 19.7%, 23.8% in the B group respectively. OR of high CV event risk in alternate shift was 2.58 (95% CI 1.33~5.00) in comparison with double shift pattern and OR in PDAR ≥ 0.5 was 2.18 (95% CI 1.15~4.14).

Conclusion

Middle aged male drivers in a big city of Korea stand a higher chance of developing CV event than other professions of the same age.

miR-125b transcriptionally increased by Nrf2 inhibits AhR repressor, which protects kidney from cisplatin-induced injury

MicroRNAs (miRNAs) have a role in the cellular defense mechanism. Nuclear factor erythroid-2-related factor 2 (Nrf2) increases antioxidant enzyme capacity. However, miRNA transcriptionally controlled by Nrf2 had been uncharacterized. Here we report that miR-125b is transactivated by Nrf2 and inhibits aryl hydrocarbon receptor (AhR) repressor (AhRR). Bioinformatic approaches enabled us to extract six candidate miRNAs. Of them, only miR-125b was increased in the kidney of mice treated with oltipraz. Nrf2 overexpression enhanced primary, precursor and mature miR-125b levels. Functional assays revealed MIR125B1 is a bona fide target gene of Nrf2. Oltipraz treatment protected the kidney from cisplatin toxicity with increase of miR-125b. Consistently, Nrf2 knockout abrogated an adaptive increase of miR-125b elicited by cisplatin, augmenting kidney injury. An integrative network of miRNA and messenger RNA changes enabled us to predict miR-125b as an inhibitor of AhRR for the control of AhR activity and cell survival. In our molecular study, miR-125b inhibited AhRR and thereby activated AhR, leading to the induction of mdm2. Consistently, p53 activation by cisplatin was diminished by either miR-125b or oltipraz treatment. The results of experiments using miR-125b mimic or small interfering RNA of AhRR verified the role of miR-125b in AhRR regulation for kidney protection. In conclusion, miR-125b is transcriptionally activated by Nrf2 and serves as an inhibitor of AhRR, which contributes to protecting kidney from acute injury.

Clinical analysis of microscopic removal of discal cyst

Objective

The purpose of this study was to evaluate the clinical presentation and surgical outcome in patients with symptomatic discal cyst.

Methods

The authors reviewed consequent 9 patients in whom microscopic excision of the discal cyst with or without additional discectomy for discal cyst from 2005 to 2012. Diagnostic imagings including simple radiographs, computed tomography with discogram and magnetic resonance images were performed in each case. The patients were reviewed to evaluate the clinical presentation, surgical outcome and related complications.

Results

In all patients, discal cyst was located in the lumbar region and they presented with back pain and unilateral radiating pain. The preoperative magnetic resonance images (MRI) and computed tomography (CT) scan with discogram showed a connection between the cyst and the involved intervertebral disc. All patients obtained immediate relief of symptoms after microscopic excision of discal cyst. There were no recurrent lesions during follow-up period. The mean preoperative visual analogue scale (VAS) was 7.8 when compared with 2.6 in preoperative assessment. All patients obtained excellent or good outcome according to modified MacNab's criteria.

Conclusion

Discal cysts are rare lesions that can lead to back pain and refractory sciatica. Microscopic excision of the cyst can achieve remarkable improvement of symptoms.

Mobile phone use, blood lead levels, and attention deficit hyperactivity symptoms in children: a longitudinal study

BACKGROUND

Concerns have developed for the possible negative health effects of radiofrequency electromagnetic field (RF-EMF) exposure to children's brains. The purpose of this longitudinal study was to investigate the association between mobile phone use and symptoms of Attention Deficit Hyperactivity Disorder (ADHD) considering the modifying effect of lead exposure.

METHODS

A total of 2,422 children at 27 elementary schools in 10 Korean cities were examined and followed up 2 years later. Parents or guardians were administered a questionnaire including the Korean version of the ADHD rating scale and questions about mobile phone use, as well as socio-demographic factors. The ADHD symptom risk for mobile phone use was estimated at two time points using logistic regression and combined over 2 years using the generalized estimating equation model with repeatedly measured variables of mobile phone use, blood lead, and ADHD symptoms, adjusted for covariates.

RESULTS

The ADHD symptom risk associated with mobile phone use for voice calls but the association was limited to children exposed to relatively high lead.

CONCLUSIONS

The results suggest that simultaneous exposure to lead and RF from mobile phone use was associated with increased ADHD symptom risk, although possible reverse causality could not be ruled out.

Early volumetric change and treatment outcome of metastatic brain tumors after external beam radiotherapy: differential radiotherapy for brain metastasis

PURPOSE

To evaluate the treatment outcomes of low-dose whole brain radiation therapy (WBRT)-based differential radiation therapy (RT) for metastatic brain tumors.

METHODS

A total of 242 targets (metastatic brain lesions) were analyzed in the present study. Median WBRT dose and number of fractions were 25 (range 25-35) Gy and 10 (range 8-15) fractions, respectively. A median normalized total dose (NTD) of 1.8 Gy (NTD(1.8Gy)) to the metastatic lesion was 45 (range 27-64.8) Gy. We numbered and contoured each metastatic lesion sequentially using computed tomography fused with serial magnetic resonance imaging to evaluate volumetric changes.

RESULTS

The 6-month and 1-year freedom from remote intracranial failure rates were 87.7 and 58.5 %, respectively. The 6-month actuarial local control (LC) rate was 93.4 %. Tumor diameter was a major determinant for LC, and tumor histology was a significant parameter predicting the volume reduction rate. With overall complete response (CR) rate of 56.6 % after RT, CR rate, if the target was more than 1 cm in size, was 25 % with a median NTD(1.8Gy) of 45 Gy, requiring dose escalation to achieve better target regression.

CONCLUSIONS

Low-dose WBRT with selective boost was feasible and effective. Our results pose the rationale of future trial of differential radiation therapy (RT), which prescribes different radiation dose according to the tumor density in metastatic brain tumors.

Effect of environmental tobacco smoke on atopic dermatitis among children in Korea

The prevalence of atopic dermatitis is increasing in many countries. Several factors are known to be associated with childhood atopic dermatitis. Environmental tobacco smoke (ETS) is one of the most common indoor pollutants, and children are more vulnerable to ETS exposure than adults are. In this study, the possible association of ETS with atopic dermatitis was evaluated in 7030 individuals aged 6-13 years who participated in the Children's Health and Environment Research study. In addition, predictive factors, such as the allergic history of the parents, children's immunoglobulin E levels and children's history of rhinitis and its association with dermatitis, were assessed. After adjustment for possible confounding variables, atopic dermatitis was found to be highly correlated with ETS, especially among children whose mothers had smoked during pregnancy and/or in the first year after birth (OR=2.06, 95% CI: 1.01-4.22). In conclusion, our results show that childhood exposure to ETS is a major risk factor for atopic dermatitis.

Association between environmental tobacco smoke exposure of children and parental socioeconomic status: a cross-sectional study in Korea

INTRODUCTION

It has been reported that most environmental tobacco smoke (ETS) exposure of children occurs at home, and lower parental socioeconomic status (SES) increases the risk of this exposure. We estimated the independent and interactive effects of parental SES and residential area SES on ETS exposure of children at home.

METHODS

We evaluated whether ETS exposure was associated with parental SES by entering data from 7,059 school-aged children in Korea into fixed effects models. The empirical model, including the interaction variable of the level of deprivation of each residential area, was fitted with parental SES.

RESULTS

After adjustment for possible confounding variables, low paternal education (odds ratio [OR], 1.81; 95% CI, 1.30-2.54) and highly deprived areas (OR, 1.34; 95% CI, 1.06-1.69) were significantly associated with the ETS exposure of children, especially among children whose fathers had <12 years of education and lived in the most deprived area (OR, 2.04; 95% CI, 1.04-4.02).

CONCLUSIONS

Our findings suggest that the SES of residential areas may influence the ETS exposure of children directly, as well as interactively with parental SES, in Korea. Findings from this study will help inform policy decision makers that intervention to promote smoking cessation should consider not only the SES of individuals but also that of residential areas.

Effects of early measles on later rhinitis and bronchial hyperresponsiveness

BACKGROUND

The hygiene hypothesis suggests that infectious diseases in early life reduce the risk of allergic diseases.

OBJECTIVE

To investigate the association between measles infection during early childhood and the prevalence of allergic diseases, lung function, bronchial hyperresponsiveness (BHR), and sensitization in later childhood.

METHODS

A survey was conducted 5 years after a nationwide measles outbreak in Korea. From September 1 through November 30, 2006, we obtained information on history of measles and allergic diseases but not of measles vaccination through a questionnaire completed by 1004 schoolchildren aged 6 to 7 years. Furthermore, we measured measles antibody titers and performed skin prick tests, pulmonary function tests, and methacholine challenge tests. Children were divided into groups based on their history of measles infection and antibody titers.

RESULTS

Prevalence of measles infection was 8.2%. Children with both a positive measles history and a positive antimeasles antibody had significantly higher antimeasles antibody levels than those without a measles history. The prevalence of current rhinitis (adjusted odds ratio [aOR], 1.86; 95% confidence interval [CI], 1.02-3.40), rhinitis ever (aOR, 2.17; 95% CI, 1.19-3.94), and current BHR (aOR, 1.98; 95% CI, 1.04-3.78) was significantly higher in the group with a positive measles history compared with the group with a negative measles antibody. No differences were found among groups in the prevalence of asthma, lung function, provocation concentration that caused a decrease in forced expiratory volume of 1 second of 20%, or sensitization.

CONCLUSION

Early measles infection was associated with increased prevalence of rhinitis and BHR at the age of 7 years but has no effect on the development of asthma and allergy at the age of 7 years. This study indicates that common childhood infections such as measles in early age do not protect against later development of allergic diseases.

Purification and Characterization of a Keratinase from a Feather-Degrading Bacillus licheniformis Strain

A keratinase was isolated from the culture medium of feather-degrading Bacillus licheniformis PWD-1 by use of an assay of the hydrolysis of azokeratin. Membrane ultrafiltration and carboxymethyl cellulose ion-exchange and Sephadex G-75 gel chromatographies were used to purify the enzyme. The specific activity of the purified keratinase relative to that in the original medium was approximately 70-fold. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and Sephadex G-75 chromatography indicated that the purified keratinase is monomeric and has a molecular mass of 33 kDa. The optimum pH and the pI were determined to be 7.5 and 7.25, respectively. Under standard assay conditions, the apparent temperature optimum was 50 degrees C. The enzyme is stable when stored at -20 degrees C. The purified keratinase hydrolyzes a broad range of substrates and displays higher proteolytic activity than most proteases. In practical applications, keratinase is a useful enzyme for promoting the hydrolysis of feather keratin and improving the digestibility of feather meal.

Genetic analysis of norovirus GII.4 variants circulating in Korea in 2008

Noroviruses are the enteric pathogens most commonly responsible for infectious gastroenteritis and outbreaks of foodborne illness. The GII.4 norovirus, in particular, is responsible for the majority of epidemics. Here, we present data on the distribution of norovirus genotypes in Chungnam, Korea, in 2008, measure genetic variation among GII.4 strains, and compare Korean GII.4 variants with reference strains based on the 237-bp junction of ORF1 and ORF2. We detected 139 different strains, which formed two distinct genetic clusters with significant sequence diversity. One Korean cluster (2008-Korea_a) showed high similarity to the Sakai cluster that appeared in Japan and Europe in 2006. The other cluster (2008-Korea_b) was unique and unrelated to previously reported clusters. Genotype GII.4 was confirmed as the predominant cause of norovirus epidemics in Korea. Foodborne norovirus infections, on the other hand, were generally caused by emerging GII.4 genetic variants similar to those responsible for global epidemics.

The nature and enhancement of magnetic surface contribution in model NiO nanoparticles

We report an alternative synthesis method and novel magnetic properties of Ni-oxide nanoparticles (NPs). The NPs were prepared by thermal decomposition of nickel phosphine complexes in a high-boiling-point organic solvent. These particles exhibit an interesting morphology constituted by a crystalline core and a broad disordered superficial shell. Our results suggest that the magnetic behavior is mainly dominated by strong surface effects at low temperature, which become evident through the observation of shifted hysteresis loops (approximately 2.2 kOe), coercivity enhancement (approximately 10.2 kOe) and high field irreversibility (>or=50 kOe). Both an exchange bias and a vertical shift in magnetization can be observed in this system below 35 K after field cooling. Additionally, the exchange bias field shows a linear dependence on the magnetization shift values, which elucidate the role of pinned spins on the exchange fields. The experimental data are analyzed in terms of the interplay between the interface exchange coupling and the antiferromagnetically ordered structure of the core.

The influence of lagoon on neighboring rivers by water and sediment quality

Canonical discriminant analysis (CDA) was applied in order to distinguish the water-quality and the sediment-quality parameters from neighboring rivers, and to recognize similarities of water and sediment properties between a lagoon and neighboring rivers. Two set of constructed discriminant functions showed a marked contribution to most of the discriminant variables. In water, the significant parameters - the total nitrogen, algae, dissolved oxygen and total phosphate - were combined as the nutrient effect factor. The recognition capacities of the two discriminant functions were 95.6 and 4.4%, respectively; the Kaoping River showed the most similarities with the water quality in Dapeng Bay; in sediment, the significant parameters porosity, Cd, Cr, Al, and Pb were combined as the heavy metal effect factor. The recognition capacities were 82.6 and 17.4%, respectively, but the sediment properties in these three rivers had no significant similarity with the Dapeng Bay.

Role of interparticle interactions on the magnetic behavior of Mg(0.95)Mn(0.05)Fe(2)O(4) ferrite nanoparticles

We present here a detailed investigation of the static and dynamic magnetic behavior of a Mg(0.95)Mn(0.05)Fe(2)O(4) spinel ferrite nanoparticle system synthesized by high-energy ball milling of almost identical particle size distributions ([Formula: see text], 5.1 and 6.0 ± 0.6 nm). The samples were characterized by using x-ray diffraction, Mössbauer spectroscopy, dc magnetization and frequency dependent real χ(')(T) and imaginary χ('')(T) parts of ac susceptibility measurements. The zero-field-cooled (ZFC) and field-cooled (FC) magnetization have been recorded in a low field and show a behavior typical of superparamagnetic particles above a temperature of 185 ± 5 K, which is further supported from the temperature dependent Mössbauer measurements. The fact that the blocking temperature calculated from the ZFC magnetization and Mössbauer data are almost similar gives a clear indication of the interparticle interactions among these nanoparticle systems. This is further supported from the FC magnetization curves, which are almost flat below a certain temperature (less than the blocking temperature), as compared with the monotonically increasing behavior characteristics of non-interacting superparamagnetic particles. A shift of the blocking temperature with increasing frequency was observed in the real χ(')(T) and imaginary χ('')(T) parts of the ac susceptibility measurements. The analysis of the results shows that the data fit well with the Vogel-Fulcher law, whereas trials using the Neel-Brown and power law are unproductive. The role of magnetic interparticle interactions on the magnetic behavior, namely superparamagnetic relaxation time and magnetic anisotropy, are discussed.

Chronic stress evaluation using neuro-fuzzy

The purpose of this research was to evaluate chronic stress using physiological parameters. Wistar rats were exposed to sound stress for 14 days. Biosignals were acquired hourly. To develop a fuzzy inference system that can integrate physiological parameters, the parameters of the system were adjusted by the adaptive neuro-fuzzy inference system. Of the training dataset, the input dataset was the physiological parameters from the biosignals and the output dataset was the target values from the cortisol production. Physiological parameters were integrated using the fuzzy inference system, then 24-hour results were analyzed by the Cosinor method. Chronic stress was evaluated from the degree of circadian rhythm disturbance. Suppose that the degree of stress for initial rest period was 1. Then, the degree of stress after 14-day sound stress increased to 131, and increased to 1.47 after the 7-day recovery period. That is, the rat was exposed to 37%increased amount of stress by the 14-day sound and did not recover after the 7-day recovery period.

Water quality assessment and apportionment source of pollution from neighbouring rivers in the Tapeng Lagoon (Taiwan) using multivariate analysis: a case study

Factor analysis was conducted to explain the characteristics and variation in the quality of water during the disassembly of oyster frames and fishery boxes. The result shows that the most important latent factors in the Tapeng Lagoon are the ocean factor, the primary productivity factor, and the fishery pollution factor. Canonical discriminant analysis is applied to identify the source of pollution in neighbouring rivers outside the Tapeng Lagoon. The two constructed discriminant functions (CDFs) showed a marked contribution to all the discriminant variables, and that total nitrogen, algae, dissolved oxygen, and total phosphate combined in the nutrient effect factor. The recognition capacities in these two CDFs were 95.6% and 4.4%, respectively. The water quality in the Kaoping river most strongly affected the water quality in the Tapeng Lagoon. Disassembling the oyster frames and fishery boxes improved the water quality markedly. However, environmental topographic conditions indicate that strengthening stream pollution prevention and constructing another entrance to the ocean are the best approaches for improving the quality of water in the Tapeng Lagoon by reducing eutrophication. These approaches and results yield useful information concerning habitat recovery and water resource management.

Excess post-exercise oxygen consumption in adult sockeye (Oncorhynchus nerka) and coho (O. kisutch) salmon following critical speed swimming

The present study measured the excess post-exercise oxygen cost (EPOC) following tests at critical swimming speed (Ucrit) in three stocks of adult, wild, Pacific salmon (Oncorhynchus sp.) and used EPOC to estimate the time required to return to their routine level of oxygen consumption (recovery time) and the total oxygen cost of swimming to Ucrit. Following exhaustion at Ucrit, recovery time was 42-78 min, depending upon the fish stock. The recovery times are several-fold shorter than previously reported for juvenile, hatchery-raised salmonids. EPOC varied fivefold among the fish stocks, being greatest for Gates Creek sockeye salmon (O. nerka), which was the salmon stock that had the longest in-river migration, experienced the warmest temperature and achieved the highest maximum oxygen consumption compared with the other salmon stocks that were studied. EPOC was related to Ucrit, which in turn was directly influenced by ambient test temperature. The non-aerobic cost of swimming to Ucrit was estimated to add an additional 21.4-50.5% to the oxygen consumption measured at Ucrit. While these non-aerobic contributions to swimming did not affect the minimum cost of transport, they were up to three times higher than the value used previously for an energetic model of salmon migration in the Fraser River, BC, Canada. As such, the underestimate of non-aerobic swimming costs may require a reevaluation of the importance of how in-river barriers like rapids and bypass facilities at dams, and year-to-year changes in river flows and temperatures, affect energy use and hence migration success.

The effect of temperature on swimming performance and oxygen consumption in adult sockeye (Oncorhynchus nerka) and coho (O. kisutch) salmon stocks

Our knowledge of the swimming capabilities and metabolic rates of adult salmon, and particularly the influence of temperature on them, is extremely limited, and yet this information is critical to understanding the remarkable upstream migrations that these fish can make. To remedy this situation, we examined the effects of temperature on swimming performance and metabolic rates of 107 adult fish taken from three stocks of sockeye salmon Oncorhynchus nerka and one stock of coho salmon O. kisutch at various field and laboratory locations, using large, portable, swim tunnels. The salmon stocks were selected because of differences in their ambient water temperature (ranging from 5 degrees C to 20 degrees C) and the total distance of their in-river migrations (ranging from approximately 100 km for coastal stocks to approximately 1100 km for interior stocks). As anticipated, differences in routine metabolic rate observed among salmon stocks were largely explained by an exponential dependence on ambient water temperature. However, the relationship between water temperature and maximum oxygen consumption (MO2max), i.e. the MO2 measured at the critical swimming speed (Ucrit), revealed temperature optima for MO2max that were stock-specific. These temperature optima were very similar to the average ambient water temperatures for the natal stream of a given stock. Furthermore, at a comparable water temperature, the salmon stocks that experienced a long and energetically costly in-river migration were characterized by a higher MO2max, a higher scope for activity, a higher Ucrit and, in some cases, a higher cost of transport, relative to the coastal salmon stocks that experience a short in-river migration. We conclude that high-caliber respirometry can be performed in a field setting and that stock-specific differences in swimming performance of adult salmon may be important for understanding upstream migration energetics and abilities.

A feasibility study using three-dimensional conformal boost technique in locally advanced carcinoma of the nasopharynx

To investigate the feasibility and efficacy of dose escalation using three-dimensional (3-D) conformal boost technique, 21 patients with stage III or IV nasopharyngeal cancer were enrolled in a prospective protocol. All patients with node metastases initially received external radiotherapy by conventional technique up to 70.2 Gy, followed by 3-D conformal radiotherapy (3-D CRT) to the boost part up to 79.2 Gy with 9 Gy increments (daily fraction of 1.8 Gy for 5 days). A modified technique with the same dose escalation of 9 Gy using 3-D CRT was applied to 7 patients without node metastases, who were treated by conventional technique up to 54 Gy, followed by 3-D CRT to boost up to a basic dose of 70.2 Gy, and then finally with dose escalation of 9 Gy. The protocol was relatively well tolerated by the majority of patients. Acute complications during the dose escalation schedule was low, with rare occurrences of grade 3 or 4 toxicity. Although late radiation-induced complications also appeared limited, 1 patient developed a temporal lobe necrosis and 2 patients suffered from sensory-neural hearing loss. There were no radiation-induced fatal complications. At a median follow-up of 48 months, only 3 patients experienced local failure and 2 patients developed distant metastases. The 5-year overall actuarial survival rate and recurrence-free survival rate for all patients were 68% and 85%, respectively. On the basis of acceptable morbidity and encouraging treatment results, we conclude that the dose escalation in 9 Gy increments using a 3-D conformal boost technique is relatively safe and efficacious, enough to be used routinely for locally advanced nasopharyngeal cancers.

Dyspnea and palpitation during pregnancy

OBJECTIVES

Dyspnea and palpitation are common features of pregnancy. While several theories have been put forward to explain the etiology of gestational dyspnea and palpitation, there have been few systemic studies of its incidence, severity and time-course in a group of normal women.

METHODS

We interviewed postpartum women, within 3 days after delivery, about dyspnea and palpitation. Separately from this interview, we performed 24-hour ECG monitoring for obstetric patients with palpitation before delivery.

RESULTS

The subjects interviewed were 261 women, of whom 37.5 percent and 11.5 percent experienced dyspnea and palpitation, respectively. These symptoms had tendency to increase to term. The presence of arrhythmias could be documented in only 22% of patients having 24-hour Holter monitoring.

CONCLUSION

Dyspnea and palpitation were common among normal pregnant women and had a tendency to increase to term.

Epstein-Barr virus-associated B cell lymphoproliferative disorder following mismatched related T cell-depleted bone marrow transplantation

Epstein-Barr virus (EBV) is closely associated with the progressive and often fatal lymphoproliferative disorders (LPD) in post bone marrow transplantation (BMT) and immunocompromised hosts. The incidence increases significantly when alternative donors or manipulation of marrow graft are used. A total of 318 consecutive BMT from partially mismatched related family donors (PMRD) were performed between February 1993 and June 1998. Known risk factors for the development of EBV-LPD were analyzed which included HLA mismatches, T cell depletion, antithymocyte globulin (ATG), and graft-versus-host disease (GVHD). Eighteen patients (5.7%) developed EBV-LPD at a median of 137 days post BMT (range 48-617). The estimated probability of developing EBV-LPD was 0.13 (95% CI 0.07-0.19) at 5 years. The incidence of grade II to IV GVHD was 19.2%, which translated into an increased trend of EBV-LPD. No correlation with other risk factors was observed. Treatment consisted of supportive antiviral agents, tapering of immunosuppressive regimens, donor leukocyte infusions and radiation. Three patients are alive and disease-free at a median follow-up of 69 months (range 36-71). We observed a lower than expected incidence of EBV-LPD despite existing multiple high-risk factors. We believe prevention and early control of GVHD may contribute to this finding.

Airway inflammation and remodeling in asthma. Lessons from interleukin 11 and interleukin 13 transgenic mice

Noninflammatory structural alterations, variously referred to as airway remodeling, are well documented in the asthmatic airway. However, the pathogenesis of these alterations, the importance of airway remodeling in generating the asthma phenotype, and the natural history of airway remodeling responses have not been adequately defined. Because exaggerated cytokine production is a characteristic feature of the asthmatic airway, we used constitutive and inducible overexpression transgenic systems to investigate the contributions that interleukin 11 (IL-11) and IL-13 might make to airway remodeling responses. These studies demonstrated that both cytokines produce responses in the murine airway with features similar to those in human asthmatic tissues. IL-11 caused airway fibrosis with the enhanced accumulation of interstitial collagens, myocytes, and myofibroblasts. IL-13 caused mucous metaplasia, enhanced mucin gene expression, enhanced tissue hyaluronic acid accumulation, and subepithelial fibrosis. Importantly, IL-11 was detected most readily in tissues from asthmatic subjects with severe airway remodeling that was similar to that seen in the IL-11 transgenic mice. In addition, IL-11 was shown to inhibit asthma-like inflammation while stimulating airway fibrosis. This suggests that IL-11 elaboration is, in part, an attempt at airway healing. Last, a novel triple transgenic system is described that allows transgene expression to be regulated in a true "on/off" manner. This system may be useful in defining the reversibility of transgene-induced airway remodeling responses.

The Mdm-2 amino terminus is required for Mdm2 binding and SUMO-1 conjugation by the E2 SUMO-1 conjugating enzyme Ubc9

Covalent attachment of SUMO-1 to Mdm2 requires the activation of a heterodimeric Aos1-Uba2 enzyme (ubiquitin-activating enzyme (E1)) followed by the conjugation of Sumo-1 to Mdm2 by Ubc9, a protein with a strong sequence similarity to ubiquitin carrier proteins (E2s). Upon Sumo-1 conjugation, Mdm2 is protected from self-ubiquitination and elicits greater ubiquitin-protein isopeptide ligase (E3) activity toward p53, thereby increasing its oncogenic potential. Because of the biological implication of Mdm2 sumoylation, we mapped Ubc9 binding on Mdm2. Here we demonstrate that Ubc9 can associate with Mdm2 only if amino acids 40-59 within the N terminus of Mdm2 are present. Mdm2 from which amino acids 40-59 have been deleted can no longer be sumoylated. Furthermore, addition of a peptide that corresponds to amino acids 40-59 on Mdm2 to a sumoylation reaction efficiently inhibits Mdm2 sumoylation in vitro and in vivo. In UV-treated cells Mdm2 exhibits reduced association with Ubc9, which coincides with decreased Mdm2 sumoylation. Our findings regarding the association of Ubc9 with Mdm2, and the effect of UV-irradiation on Ubc9 binding, point to an additional level in the regulation of Mdm2 sumoylation under normal growth conditions as well as in response to stress conditions.

Primary squamous cell carcinoma of the parotid gland

PURPOSE

To investigate the clinical behavior and treatment outcome of patients with primary squamous cell carcinoma (SCC) of the parotid gland.

PATIENTS AND METHODS

Twelve cases of primary SCC originating in the parotid gland were retrospectively reviewed. The majority of patients had a locally advanced disease. Eight cases underwent a combination of radical surgery and postoperative radiotherapy, whereas the remaining four cases were treated with radiotherapy alone. Patterns of treatment failure, survival rate, and prognostic factors for these patients were investigated.

RESULTS

The predominant pattern of failure was local failure, either alone or in combination with other failures. Two patients who were treated with radiation alone had persistent disease after completion of treatment, whereas 4 of 8 patients who received combined modality treatment and 2 of 4 patients who were treated with radiation alone subsequently developed local recurrences in the primary site or surgical bed. The local failure rate and regional failure rate were 58% and 25%, respectively. Most locoregional recurrences developed within 1 year after initial treatment. Only 2 patients had distant metastasis. The prognosis appeared to be relatively poor for those patients, compared with those with SCC in other head and neck sites. The overall 5-year actuarial survival rate and the disease-free survival rate were 31% and 33%, respectively. Although advanced stage, facial nerve palsy, and regional lymph node metastasis all portended an unfavorable prognosis, only patient age and treatment modality were found to be statistically significant poor prognostic factors.

CONCLUSIONS

Primary SCC of the parotid gland is an uncommon tumor with a highly malignant potential. Our results indicate that a combination of radical surgery and postoperative radiotherapy is the treatment of choice for achieving better locoregional control rates and improved cure rates in the treatment of these patients.

Enhancement of the p300 HAT activity by HIV-1 Tat on chromatin DNA

HIV-1 Tat is able to form a ternary complex with P/CAF and p300 and increase the affinity for CDK9/P-TEFb CTD kinase complex. Our previous study demonstrated that Tat binds to p300/CBP in the minimal HAT domain (aa 1253-1790) and that the interaction results in a change of conformation on p300/CBP. Here, we show that the Tat-p300 interaction increases the HAT activity of p300 on histone H4 that is associated with nucleosomal DNA and not with free histones. Nucleosomal histone H4 was acetylated on lysines 8, 12, and 16. Acetylation of H4 was inhibited by Lys-coenzyme A (CoA), a selective inhibitor of p300 acetyltransferase activity. Unexpectedly, we also found that Tat could autoacetylate itself, which was specific to lysine residues 41 and 71. Peptides lacking these two lysines could not enhance the HAT activity of p300. Comparison of the sequences of Tat with other HIV-1 clades and HAT containing transcription factors indicated sequence identity in the acetyl-CoA binding motif A, KGXG. Furthermore, when utilizing an in vitro transcription assay, as well as a Tat mutant virus, we found that ectopic expression of only wild-type Tat in the presence of p300, and not a lysine 41 Tat mutant, could activate HIV-1 chromatin DNA, as evidenced by the absence of HIV-1 virion antigen. Therefore, transcription of integrated viral DNA in vivo requires the HAT activity of coactivators that are modulated by Tat to derepress the HIV-1 chromatin structure and aid in activated transcription.

Enzyme-linked immunosorbent assay for detection of Trichinella spiralis antibodies and the surveillance of selected pig breeding farms in the Republic of Korea

Trichinellosis is a parasitic zoonosis of public health importance. It is caused by Trichinella spiralis which has a wide host range including humans. In the present communication, the ELISA technique was employed on a total of 803 blood samples from 7 selected pig breeding farms in 1996 for diagnosis and surveillance of trichinellosis. Out of the entire 803 samples, nine were found to be suspected while one was positive by ELISA. But western blot analyses employed for further confirmation have shown that all of 10 samples did not react to larval excretory-secretory product antigens. These results indicate that pig breeding farms included in the present study are free from trichinellosis. However, it does not mean Korea is free from trichinellosis since human trichinellosis has recently been reported. The necessity of continued surveillance for trichinellosis in both pigs and wild animals was discussed.

Hemodynamic effects of lipids in humans

Evidence suggests lipid abnormalities may contribute to elevated blood pressure, increased vascular resistance, and reduced arterial compliance among insulin-resistant subjects. In a study of 11 normal volunteers undergoing 4-h-long infusions of Intralipid and heparin to raise plasma nonesterified fatty acids (NEFAs), we observed increases of blood pressure. In contrast, blood pressure did not change in these same volunteers during a 4-h infusion of saline and heparin. To better characterize the hemodynamic responses to Intralipid and heparin, another group of 21 individuals, including both lean and obese volunteers, was studied after 3 wk on a controlled diet with 180 mmol sodium/day. Two and four hours after starting the infusions, plasma NEFAs increased by 134 and 111% in those receiving Intralipid and heparin, P < 0.01, whereas plasma NEFAs did not change in the first group of normal volunteers who received saline and heparin. The hemodynamic changes in lean and obese subjects in the second study were similar, and the results were combined. The infusion of Intralipid and heparin induced a significant increase in systolic (13.5 +/- 2.1 mmHg) and diastolic (8.0 +/- 1.5 mmHg) blood pressure as well as heart rate (9.4 +/- 1.4 beats/min). Small and large artery compliance decreased, and systemic vascular resistance rose. These data raise the possibility that lipid abnormalities associated with insulin resistance contribute to the elevated blood pressure and heart rate as well as the reduced vascular compliance observed in subjects with the cardiovascular risk factor cluster.