Shohei Kira

Daily walking reduces visceral adipose tissue areas and improves insulin resistance in Japanese obese subjects

OBJECTIVE It is known that the accumulation of abdominal fat is one of the risk factors for atherosclerosis. Although exercise is commonly prescribed to reduce body weight, the efficacy of low intensity exercise for the reduction of abdominal visceral adipose tissue remains to be investigated. RESEARCH DESIGN AND METHODS Thirty one obese Japanese males (body mass index (BMI) > or = 25) ranging in age from 32 to 59, participated in a 1-year follow up study and they were instructed to have a modest increase in daily activity and record their daily walking. Before and after exercise prescription, body composition, blood pressure, physical fitness i.e. aerobic exercise level, muscle strength and flexibility were recorded. Insulin resistance was evaluated using a homeostasis model assessment, the HOMA index. RESULTS HOMA index, parameters of body composition, blood pressure, triglyceride and HDL cholesterol were significantly improved. The aerobic exercise level, leg strength, weight-bearing index (leg strength/body weight) and the steps taken per day were significantly increased. By stepwise multiple regression analysis, Delta visceral adipose tissue area was the major determinant for Delta HOMA index. (Delta HOMA index=-0.386+0.016 Delta visceral adipose tissue area, r2=0.267, P<0.01). Exercise capacity and calorie intake were not significantly related to Delta visceral adipose tissue area, while Delta steps per day was significantly correlated with Delta visceral adipose tissue area (Delta visceral adipose tissue area=-21.363-0.004 Delta steps per day, r2=0.184, P=0.0326). CONCLUSIONS Taken together, intra-abdominal visceral adipose tissue is critically involved in insulin resistance and daily walking rather than improvement of exercise capacity correlated with the reduction of visceral adipose tissue in obese Japanese males.

Quantitative determination of urinary hippuric acid and m- or p-methylhippuric acid as indices of toluene and m- or p-xylene exposure by high performance liquid chromatography.

SummaryA high performance liquid chromatographic method for the determination of hippuric and m-(p-)methylhippuric acids in urine, metabolites of toluene and m-(p-)xylene, is described. A stainless-steel column packed with octadecyl silanized silica gel was used and the mobile phase was a mixed solution of methanol/water/acetic acid (20/80/0.2). The method is simple and specific. Urine can be analyzed directly, without solvent extraction or pretreatment. The method has a lower detection limit of 0.2 μg on column. All the analysis and quantitative determination can be performed within about 30 min. for samples containing m-(p-)methylhippuric acid.

Relationship between reduced serum IGF-I levels and accumulation of visceral fat in Japanese men.

OBJECTIVE: To investigate whether the changes in IGF-I concentrations after weight reduction in Japanese overweight men are associated with changes in visceral and subcutaneous fat.DESIGN: Cross-sectional and longitudinal clinical intervention study with exercise education.SUBJECTS: One-hundred and twelve Japanese overweight men aged 30–59 y (body mass index (BMI) 28.4±2.5 kg/m2) and 33 normal-weight men aged 30–39 y (BMI 22.1±1.5 kg/m2) at baseline. From the participants, 56 randomly selected overweight men (BMI 28.8±2.8) were further enrolled into a 1 y exercise program.MEASUREMENTS: Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography scanning at umbilical levels, metabolic parameters and hormones including insulin, leptin and IGF-I at baseline and after 1 y.RESULTS: In 112 overweight subjects at baseline, insulin (10.5±5.0 µU/ml) and leptin (6.4±3.7 ng/ml) significantly correlated with both V (r=0.260, P=0.0073; r=0.410, P<0.0001) and S areas (r=0.377, P<0.0001; r=0.613, P<0.0001), respectively. IGF-I (156.8±48.7 µU/ml) significantly and negatively correlated with V area (r=−0.242, P=0.0125) and age (r=−0.192, P=0.0480). In normal-weight men aged 30–39 y (n=33) and age-matched subjects (n=30) selected from the 112 overweight men, the serum IGF-I further tightly correlated with V area (r=−0.467, P<0.0001). Visceral fat area and age were independently related to serum IGF-I levels by multiple regression analysis. By intervention with exercise education, 56 overweight subjects showed an increase in daily steps (6224±2781 to 7898±4141 steps/day) and reduction of BMI (28.8±2.8 to 27.7±2.9). ΔIGF-I significantly correlated with ΔV area (r=−0.432, P=0.0009) but not with ΔS area or ΔBMI.CONCLUSION: The present study indicated a negative correlation between IGF-I levels and visceral fat at baseline as well as an association between the reduction in visceral fat and increase in IGF-I levels after an exercise intervention.

Changes in serum leptin concentrations in overweight Japanese men after exercise

Aim:  To investigate the link between serum leptin concentrations and exercise.

Lead content of brain tissue in diffuse neurofibrillary tangles with calcification (DNTC): the possibility of lead neurotoxicity.

Diffuse neurofibrillary tangles with calcification (DNTC) is a form of presenile dementia, characterized pathologically by fronto-temporal atrophy with neurofibrillary tangles (NFTs), neuropil threads and Fahr-type calcification, in which no senile plaques are observed. As already noted, chronic exposure to lead (Pb) might be one of the etiological factors of Fahr-type calcification. Until now, there have been no reports in which Pb concentration has been quantified in DNTC brains. We examined the concentration of Pb in fresh-frozen brain tissue and in 10% formalin-fixed brain tissue from six cases of DNTC, four cases of Alzheimers disease, and in nine non-demented elderly controls by flameless atomic absorption spectrometry, and demonstrated a high concentration of Pb in DNTC brains. Although it remains unclear how these findings are related to the formation of NFTs, they suggest that Pb neurotoxicity may be involved in the pathogenesis of DNTC.

Detection of Mutagenicity in Mussels and Their Ambient Water

Mussels provide an excellent system for monitoring marine pollutants: the system is often called mussel watch. Investigators have reported the susceptibility of this organism to petroleum hydrocarbons and polynuclear aromatic hydrocarbons. The authors showed the applicability of this organism to monitor oil pollutions by detecting organosulfur compounds in field samples. In the present study, they undertook the mutagen screening of mussel bodies and ambient water, and investigated the correlation between the mussel- and water-mutagenicities. Mutagenic compounds being detected here are those adsorbable to blue cotton or blue rayon and extractable with a methanol-ammonia solution, and the Ames assay was used for the detection of mutagenicity, with Salmonella typhimurium TA98 as the ester strain and with S9-mix for metabolic activation.

cDNA cloning and expression of mutant catalase from the hypocatalasemic mouse: comparison with the acatalasemic mutant.

Mutant catalase cDNAs from the hypocatalasemic and acatalasemic mice were cloned and expressed in bacteria. A novel missense mutation, Asp (AAT) to Ser (AGT), was identified at amino acid position 439 of the hypocatalasemic catalase. Analysis of recombinant catalase mutants revealed that the mutation is responsible for the reduced activity of hypocatalasemic catalase and the unstable tetrameric structure of acatalasemic catalase was also suggested.

The prevalence of pleural plaques and/or pulmonary changes among construction workers in Okayama, Japan

BACKGROUND Since asbestos has been widely used in Japanese building materials since 1960s, a large number of Japanese construction workers may be exposed to asbestos occupationally. METHODS Among 2951 construction workers in Okayama, Japan, the prevalence of asbestos-induced pleural or pulmonary changes was examined by screening chest x-rays; these findings were confirmed by computed tomography (CT) scanning of the chest. RESULTS Among 2951 construction workers, 168 (5.7%) were found to have significant findings for pleural plaque or pulmonary changes on chest x-ray. Seventy-four had both pleural plaque and asbestosis, 85 pleural plaques alone, and 9 asbestosis alone. In 11 subjects, pleural plaques were suggested by chest x-ray, but neither pleural plaque nor asbestosis was demonstrated by chest CT. Honeycombing as one of the characteristic findings of asbestosis was found in 29 subjects. Others showed subpleural spots or curvilinear shadow, which suggested the early stage of asbestosis. The occupations of these workers were carpenters (64), plasterers (27), and concrete board cutters (14). About 30% of the workers with these findings were aware that they were handling asbestos in activities such as installation of asbestos boards, and/or asbestos spraying. CONCLUSIONS As the incidence of malignant mesothelioma and primary lung cancer associated with asbestos exposure are high, screening by chest CT is necessary for detecting asbestos-induced pulmonary and/or pleural lesions. Education for protection such as telling about the presence of asbestos in building materials is also necessary.

Serum bFGF levels are reduced in Japanese overweight men and restored by a 6-month exercise education.

OBJECTIVE: To investigate whether the changes in vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) concentrations before and after weight reduction in Japanese overweight men are associated with changes in body mass index (BMI), visceral, subcutaneous fat, VO2 and work rate (WR) at ventilatory threshold (VT).DESIGN: Cross-sectional and longitudinal clinical intervention study with exercise education.SUBJECTS: In total, 30 Japanese overweight men (BMI, 29.0±2.2 kg/m2) and 31 normal-weight men (BMI, 22.5±1.6 kg/m2) at baseline were enrolled: 30 overweight men (BMI, 29.0±2.2 kg/m2) were further enrolled into a 6-month exercise program.MEASUREMENTS: Fat distribution evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography scanning at umbilical levels, angiogenic peptides including VEGF and bFGF, exercise tests at baseline and after 6 months.RESULTS: In normal-weight and overweight subjects at baseline, VEGF positively correlated with S area (r=0.350, P=0.007) but not with V area. In contrast, bFGF negatively correlated with BMI (r=−0.619, P<0.001), S (r=−0.457, P<0.001) and V areas (r=−0.466, P<0.001). By intervention with exercise education, 30 overweight subjects showed reduction in BMI (29.0±2.2 to 28.0±2.0, P<0.001), V and S areas, increase in VO2 and WR at VT, increase in bFGF (9.21±5.82–21.2±7.04 ng/ml, P<0.001), and no change in VEGF (1.45±0.72–1.88±0.52 ng/ml, P=0.016). The stepwise multiple regression analysis revealed that ΔBMI (β=−6.052) and ΔVO2 (β=2.806) were independently related to ΔbFGF (P<0.001) and all other variables including ΔS area, and ΔV area, and ΔWR did not enter the equation at significant levels.CONCLUSION: The present study indicated a negative correlation between serum bFGF levels and BMI at baseline as well as an association of ΔBMI and ΔVO2 with ΔbFGF after exercise intervention. The exercise-induced elevation of bFGF may be beneficial in the prevention of the atherosclerosis in overweight subjects.

Transfer to fish of petroleum paraffins and organic sulfur compounds

Abstract Eels were maintained in a controlled laboratory environment in water with suspensions of crude oil. Gas chromatography of the eel flesh revealed the presence of paraffins and organic sulfur compounds whose concentration increased with rearing time.