The effect of diabetes on 4-year changes of hearing thresholds in male workers exposed to noise in a single company: a longitudinal study.

Background: Recently, several studies have assessed the association between diabetes and hearing impairment. However, the effect of diabetes on hearing impairment is not well known in diabetic patients exposed to noise, a typical cause of hearing impairment. The aim of this study is to longitudinally analyze the effect of diabetes on hearing impairment in workers exposed to similar noise levels from 2013 to 2017 who had experienced little change in their working conditions.

Arsenic levels in the groundwater of Korea and the urinary excretion among contaminated area.

Drinking water is a main source of human exposure to arsenic. Hence, the determination of arsenic in groundwater is essential to assess its impact on public health. Here, we report arsenic levels in the groundwater of 722 sites covering all six major provinces of Korea.

Relationship of cigarette smoking and hearing loss in workers exposed to occupational noise.

Objectives: To investigate the effects of smoking on hearing loss among workers exposed to occupational noise.

Methods: From the results of a special workers health examination performed in 2011, we enrolled 8,543 subjects exposed to occupational noise and reviewed the findings. Using self-reported questionnaires and health examination results, we collected data on age, smoking status, disease status, height, weight, and biochemistry and pure tone audiometry findings.

Cohort study for the effect of chronic noise exposure on blood pressure among male workers in Busan, Korea.

Objective: It has not yet been established whether exposure to chronic noise induces an increase in blood pressure or an increase in the development of hypertension. Therefore, a cohort study was performed to identify the effects of chronic noise exposure on blood pressure.

Methods: Five hundred thirty male workers at a metal manufacturing factory in Busan, Korea, were enrolled in the study.

Arsenite-enhanced procoagulant activity through phosphatidylserine exposure in platelets.

Numerous epidemiological studies have reported the close relationship between arsenic in drinking water and cardiovascular disease (CVD), yet the exact mechanism underlying this relationship remains unclear. We investigated whether arsenic can affect the procoagulant activity of platelets, which are essential in blood clotting, thrombus formation, and progression of CVD. While arsenite alone did not induce procoagulant activity, it significantly enhanced thrombin-induced procoagulant activity of human platelets in a concentration- and time-dependent manner.

Comparison of disability duration of lumbar intervertebral disc disorders among types of insurance in Korea.

The incidence of work-related musculoskeletal disorder including low back pain sharply increased since 2000 in Korea. The objectives of the present study are to compare disability duration of lumbar intervertebral disc displacement among types of insurances, and to obtain its appropriate duration. The medical records of all patients whose final diagnosis in discharge summary of chart was lumber specified intervertebral disc displacement (LIVD) in 6 large general hospitals in Korea were reviewed to compare the length of admission and disability among different types of insurances.

Inorganic arsenite potentiates vasoconstriction through calcium sensitization in vascular smooth muscle.

Chronic exposure to arsenic is well known as the cause of cardiovascular diseases such as hypertension. To investigate the effect of arsenic on blood vessels, we examined whether arsenic affected the contraction of aortic rings in an isolated organ bath system. Treatment with arsenite, a trivalent inorganic species, increased vasoconstriction induced by phenylephrine or serotonin in a concentration-dependent manner.

Neurobehavioral changes of shipyard painters exposed to mixed organic solvents.

This study was conducted to evaluate neurobehavioral changes arising from occupational exposure to organic solvents among shipyard painters and to establish whether a dose-effect relation existed where there was any observed impairment of neurobehavioral performance by running the test of Simple Reaction Time (SRT), Symbol Digit Substitution (SD), and Finger Tapping Speed (FT) with a computer-assisted neurobehavioral test battery. The study group consisted of 180 shipyard painters and 60 reference workers. The workers answered a self-administered questionnaire on occupational, medical history, and demographic characteristics including age, work duration, education level, and quantity and frequency of alcohol and smoking, and performed three psychometric tests on the Korean Computerized Neurobehavioral tests.

Occupational hand-arm vibration syndrome in Korea.

Objectives: It is suspected that there is a large number of patients suffering from hand-arm vibration syndrome (HAVS) in Korea. However, no cases have been reported since 1992. This study was conducted to identify HAVS cases and determine the characteristics of the syndrome.

Whole blood and red blood cell manganese reflected signal intensities of T1-weighted magnetic resonance images better than plasma manganese in liver cirrhotics.

We examined whole blood (MnB), red blood cell (MnRBC), plasma (MnP) and urinary Mn (MnU) concentrations in 22 liver cirrhotics and 10 healthy controls to evaluate Mn concentration in which a fraction of biological samples best reflects pallidal signal intensities (pallidal index; PI) on T1-weighted magnetic resonance images (MRI) in liver cirrhotics. Increased signal intensity in the globus pallidus was observed in 18 (81.8%) of the 22 patients with liver cirrhosis.

Blood manganese concentration is elevated in iron deficiency anemia patients, whereas globus pallidus signal intensity is minimally affected.

Objectives: To determine whether blood manganese (Mn) concentration is elevated in patients with iron deficiency anemia (IDA), and whether this affects signal intensities in the globus pallidus.

Methods: Twenty-seven patients with IDA and 10 control subjects were tested for blood Mn, and brain magnetic resonance images (MRI) were also examined. Seventeen of the 27 patients were followed-up after iron therapy.

CDNA array analysis of gene expression profiles in brain of mice exposed to manganese.

This study is performed to detect changes of gene expression in substantia nigra (SN) and striatum in manganese (Mn)-exposed mice brain. The cDNA array is a recently developed molecular biological method that can detect the differential expression of several hundreds of genes simultaneously and is therefore advantageous in the study of trace metal intoxication effect at the genetic level. Using this technology, we discovered 5 genes in the mouse striatum and 9 genes in SN changed by more than 50% following Mn exposure.

Whole blood manganese correlates with high signal intensities on T1-weighted MRI in patients with liver cirrhosis.

We examined whole blood (MnB), plasma (MnP) and urinary Mn (MnU) concentrations in 33 cirrhotics and 11 healthy controls to clarify: (1) whether, in chronic liver diseases, MnB or MnP reflects pallidal signal intensities in magnetic resonance imaging (MRI); and (2) which factors in chronic liver diseases correlate with pallidal signal intensities in T1-weighted MRI. Increased signal intensity in the pallidum was observed in 27 (81.8%) of 33 patients with liver cirrhosis in T1-weighted MRI.

Calcification mimicking manganese-induced increased signal intensities in T1-weighted MR images in a patient taking herbal medicine: case report.

Characteristic high signal intensities confined to the globus pallidus on T1-weighted magnetic resonance image (MRI) can be observed in manganese (Mn)-exposed workers, however, these high signals should be differentiated from those due to other causes such as fat, hemoglobin breakdown products, melanoma, neurofibromatosis, and calcification. A 39-year-old woman was admitted with mutism and involuntary movements which had developed the day before. She had ingested two packs of liquid herbal medicine containing 0.

Effect of manganese exposure on MPTP neurotoxicities.

We used a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice model to evaluate whether manganese (Mn) exposure can affect MPTP-induced neurotoxicity. We randomly assigned adult male C57BL/6 mice (n=5-7 per group) the following treatments: SO, Mn(-) x MPTP(-); MO, Mn(+) x MPTP(-); SM, Mn(-) x MPTP(+); MM, Mn(+) x MPTP(+). Mn (MnCl(2).

Hematological changes of children exposed to volatile organic compounds containing low levels of benzene.

We conducted a cohort study to evaluate the hematological changes of children environmentally exposed to volatile organic compounds (VOCs). The study subjects comprised 192 children who consisted of 97 children living near a petrochemical estate region and 95 children living in a suburban region of Ulsan, Korea. We executed the hematological examination three times, in April, July and October.

Nasal septum perforation of welders.

During the periodic physical checkups in 1997-2000, the authors have found eleven cases of nasal septum perforation among 2,869 welders in Ulsan, Korea. They have not suffered from diseases and conditions that could cause septum perforation such as tuberculosis, syphilis, and long-term use of topical corticosteroids. And also they did not have trauma history and surgical experiences on their nasal septum.

Evaluation of activity of erythrocyte pyrimidine 5'-nucleotidase (P5N) in lead exposed workers: with focus on the effect on hemoglobin.

Anemia that accompanies lead poisoning is in part the result of various inhibitory effects of lead on heme biosynthesis. Lead also increases the rate of red blood cell destruction due to the profoundly depressed activities of erythrocyte pyrimidine 5'-nucleotidase (P5N) activities. We studied parameters of the two metabolic pathways in the workers exposed to lead to evaluate P5N in the lead exposed workers and which pathway has an effect on hemoglobin (Hb) level.