Biomedical subjects

R Ohtsuka

Publications and source records attributed to R Ohtsuka.

At least 19 recordsLinked to original sources

PubMed2006

Unexpected changes in blood pressure and hematological parameters among fasting and nonfasting workers during Ramadan in Indonesia.

OBJECTIVE: To examine the effect of Ramadan fasting on basic hematological parameters, in addition to the effects on body weight and blood pressure of fasters and nonfasters. DESIGN, SETTING, AND SUBJECTS: One hundred male outdoor workers at a vehicle terminal in a city in East Java were recruited for this study. Anthropometric measurements and blood sampling were conducted on two separate occasions, just before the start of Ramadan and in the third week of the month of Ramadan (October-November 2004). The degree of subjective compliance with Ramadan fasting (complete, partial, or none) was evaluated using a questionnaire. RESULTS: The mean body mass index (BMI) of the fasting group was, as expected, significantly lower at the second sampling period, and the decrease in BMI correlated significantly with decreased blood pressure in this group. The blood pressure was also reduced in the partial fasting and nonfasting groups, which was an unexpected result. While red blood cell production was suppressed, as evidenced by lower levels of hemoglobin, red blood cell (RBC), and packed cell volume (PCV) at the second sampling, the subjects were normocytic and normochromic, based on normal mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) levels. CONCLUSIONS: These results indicate that, regardless of fasting status, blood pressure is lower and RBC production is suppressed in subjects during the Ramadan period. These findings should be taken into account when evaluating the effects of Ramadan on the general population. To avoid the adverse effects of anemia, increased intake of iron-rich foodstuffs is recommended during the Ramadan month, regardless of fasting practice.

Adolescent↗

PubMed2006

Gender differences in dietary intake among adults of Hindu communities in lowland Nepal: assessment of portion sizes and food consumption frequencies.

OBJECTIVE: To elucidate gender differences in dietary intake among adults in lowland Nepalese communities. SUBJECTS AND METHODS: For 122 male and 195 female subjects aged 20 years and over from 94 randomly selected households, interviews using a 19-item food frequency questionnaire were conducted. To determine the portion sizes of these foods, the samples consumed by 56 subjects in a full 1-day period were weighed. Energy expenditure was estimated by time spent on daily activities. RESULTS: Gender differences in per-day energy and protein intakes were related to sex differences in body size and energy expenditure. Apparent gender differences in the crude intakes disappeared when they were expressed by nutrient density (mg or microg/MJ) since micronutrient intakes were significantly correlated with energy intake. However, males' iron intake was larger even after adjustment for energy intake, attributing to their larger portion sizes of commonly consumed staple foods and higher frequencies of consuming luxury foods (fish and tea). CONCLUSION: The intrahousehold unequal distribution of food incurs risk of iron deficiency among female subjects. SPONSORSHIP: This study was financially supported by the Ajinomoto Foundation for Dietary Culture and the Alliance for Global Sustainability Program.

Adult↗

PubMed2006

Effects of reproduction norms on contraception practice among Muslim women in Amman, Jordan.

Based on the authors' interview survey for 275 Muslim women of an ethnically divergent community in Amman, Jordan, this study examined the psychosocial effects of reproduction norms on contraception practice, using the normative interpretations of legal provisions in Islam (hukm). The categorical principal component analysis (CATPCA) reduced the eight items regarding family planning and contraception use to two factors, i.e. the pressures of childbearing and acceptability of contraception use, accounting for 55% of the total variance. Even though the majority of the female subjects were conservative rather than innovative in terms of reproduction norms and significant interrelations were observed between their reproduction norms and contraception practice, approximately 70% of the female subjects who were closely in consonance with the normative interpretations of their religious leader had used contraception. It is thus indicated that religious leaders may play significant roles in increase of contraception practice among Muslim women.

Adolescent↗

PubMed2005

Changes in histology and expression of cytokines and chemokines in the rat lung following exposure to ovalbumin.

Brown Norway (BN) and Fischer 344 (F344) rats were exposed to aerosol of 1% ovalbumin (OVA) solution for 30 min at 1 week after the second sensitization with 1 mg of OVA at 2-week intervals. Changes in the histology and expression of cytokines and chemokines in the lung were examined for up to 96 h after the exposure. The lung weight significantly increased in BN rats but not in F344 rats. Histologically, in the lung of BN rats, multiple foci of hemorrhage in the alveolar space with infiltration of eosinophils and macrophages in the surrounding alveolar septa were first observed. Thereafter, granulomatous lesions developed in the preexisting hemorrhagic foci, finally resulting in formation of multiple eosinophilic granulomas. On the other hand, in F344 rats, infiltration of eosinophils and macrophages was observed around the vessels and bronchi. Thereafter it progressed gradually, resulting in mild thickening of alveolar septa. The levels of Th1- (interferon-gamma and interleukin 2 (IL-2)) and Th2-related cytokines (IL-4 and IL-5) and chemokines (eotaxin and monocyte chemoattractant protein-1) mRNAs measured by reverse transcription-polymerase chain reaction method were elevated in the lung of both strains, and the levels were higher in BN rats than in F344 rats. These results suggest that BN rats are more sensitive to OVA-sensitization/inhalation than F344 rats and that the difference in the severity of lung lesions between BN and F344 rats may reflect the difference in the expression levels of cytokines and chemokines between these two strains.

Animals↗

PubMed2005

Multi-source water pollution in the Upper Citarum watershed, Indonesia, with special reference to its spatiotemporal variation.

The Citarum River in West Java is the largest water supplier to the Saguling Dam, which plays a major role in electric power generation for the entire Java Island and is used for the aquaculture of marketed fish. To elucidate the extent of degradation in water quality and its causes in the Upper Citarum watershed, physical, chemical and biological parameters for water samples collected from various sites were analyzed. The results demonstrate large site-to-site variations in water qualities and pollutant loads derived from various human activities such as agriculture, cattle raising and the textile industry. To halt worsening conditions of the Citarum watershed, integrated mitigation efforts should be made, taking biophysical pollution mechanisms and local socioeconomic conditions into account.

Agriculture↗

PubMed2004

Molecular polymorphism of ABO blood group gene in Austronesian and non-Austronesian populations in Oceania.

A number of archeological, linguistic, and genetic studies have been carried out on the peopling of the Pacific, while the origin of Polynesians or the Lapita people is still open to debate. The Lapita people are believed to have populated the Bismarck Archipelago more than 3600 years ago. However, their Melanesian descendants still living in the Bismarck Archipelago have not been genetically clarified yet. To address this question, polymorphism of the ABO blood group gene was investigated in the following three populations who are considered to be almost free from recent admixtures: (i) Balopa islanders as Austronesian (AN)-speaking Melanesians living in the northwestern end of the Bismarck Archipelago; (ii) Gidra as non-Austronesian (NAN)-speaking Melanesians in southwestern lowlands of Papua New Guinea; and (iii) Tongan living in Ha'apai island as AN-speaking Polynesians. Interestingly, there were marked differences in allele frequencies of ABO*A101 and ABO*A102 among the three populations. The allele frequencies of ABO*A101 and ABO*A102 were 7.9 and 19.3% in Balopa, 23.2 and 0.0% in Gidra, and 2.9 and 25.0% in Tongan. Both phylogenetic and correspondence analyses suggested that Balopa was more close to Tongan than to Gidra and that Balopa was genetically placed between Tongan and Asian populations. Our results imply that Balopa may be Melanesian descendants of the Lapita people who populated the Bismarck Archipelago.

ABO Blood-Group System↗

PubMed2002

Expression of p53 and its transcriptional target genes mRNAs in the ethylnitrosourea-induced apoptosis and cell cycle arrest in the fetal central nervous system.

Ethylnitrosourea (ENU) is an alkylating agent and we previously clarified that it induced apoptosis and cell cycle arrest in the fetal central nervous system (CNS). In the present study, we studied the expression of p53 and its transcriptional target genes to investigate the role of p53 in the ENU-induced apoptosis and cell cycle arrest in the fetal CNS following the administration to dams on day 13 of gestation (GD13). Although the enhancement of p53 mRNA expression was not detected by reverse transcription and polymerase chain reaction (RT-PCR), p53-positive signals were detected immunohistochemically in the nuclei of neuroepithelial cells of the ENU-administered fetuses from 1 hour after treatment (HAT) to 12HAT, and they were most intensive at 3HAT. On the other hand, p53-positive signals were scarcely detected in the control fetuses. Among the p53 target genes, the expression of p21, bax, cyclinG1 and fas mRNAs increased and peaked at 6HAT. In addition, strong immunoreactivity for p21 was detected in the nuclei of neuroepithelial cells of the fetuses at 6HAT. The expression of p53 protein increased prior to the induction of apoptosis and cell cycle arrest, and transcription of its target genes was also activated. The present results suggest that ENU may induce apoptosis and cell cycle arrest in the fetal neuroepithelial cells in a p53-dependent manner.

Alkylating Agents↗

PubMed2001

Physical activity and subsistence pattern of the Huli, a Papua New Guinea Highland population.

Several studies on human energetics have been conducted in developed and developing countries, but very few simultaneously measured time use and energy expenditure. Only a few quantitatively compared subsistence patterns between rural and urban dwellers of an identical population. Here we present the daily physical activity level (PAL), physical exertion, time, and energy expenditure in contrasting subsistence/occupational activities of Papua New Guinea Highlanders, comparing 27 rural villagers (15 men, 12 women) who maintained traditional subsistence agriculture, with 29 urban migrants (14 men, 15 women) who engaged in cash-earning work. A large sex inequality in the division of labor was noted between rural males and females, but not among urban dwellers. Rural-urban comparison indicated sex differences in urbanization. For urban men, the reduction of physical exertion level during work, from energy-consuming agricultural work to sedentary cash-earning work, together with significantly extended work time (by 261 min/day, P < 0.001), led to an increase in work energy expenditure (15-29% of PAL). In contrast, urban women who spent almost equal time at work relative to rural women showed a lower energy expenditure (18% compared to 26% of PAL). The associations with urbanization included a gain in body weight (by 6.4 kg for either sex) and reduced PAL (by 7%, not significant in men; 13%, P < 0.01 in women). Further research is needed to elucidate the effects of urbanization on time use, energy expenditure, and PAL, by comparing rural residents with urban migrants in the same population.

Adult↗

PubMed2001

Chronic exposure to ELF magnetic fields during night sleep with electric sheet: effects on diurnal melatonin rhythms in men.

The possible effects of repeated night-time exposure to an extremely low frequency magnetic field (ELF-MF) on melatonin were investigated in nine healthy male subjects aged 23-37 yr. The 16-week experiment consisted of 3 weeks of pre-exposure, 11 weeks of night-time exposure to MF generated from a nonheated electric sheet (ES), and 2 weeks of post-exposure recovery observation. The average MF intensity (rms, mainly 50 Hz AC) on the surface of the sheet was 0.7 microT at the head, 8.3 microT at the waist, and 3.5 microT at the feet of the subject. For each of the urine samples collected 5 times a day on scheduled sampling days, the urinary excretion rate (ng/h) of melatonin was determined, and 24 h rhythms were extracted for each subject and each experimental period (pre-exposure, first half and latter half exposure, and post-exposure periods) by the method of complex cosine curve fitting. Although estimates of the peak height, acrophase, and total daily amount of melatonin were characterized by significant variations among individual subjects, they did not reveal any statistically significant difference between exposure periods and nonexposure periods. Thus, the present study indicates that any profound effect of the MF originating from an ES on nocturnal melatonin production and its circadian rhythm is unlikely.

Adult↗

PubMed2001

Influence of urbanisation on physical activity and dietary changes in Huli-speaking population: a comparative study of village dwellers and migrants in urban settlements.

The influence of urbanisation on physical activity and dietary changes was examined in a Papua New Guinea Highland population. Adult male and female subjects (n 56) were selected, including twenty-seven rural villagers and twenty-nine urban migrants. BMR was calculated from values measured in similar samples of Huli-speaking population, according to gender and body weight. Total daily energy expenditure (TEE) was assessed by 24 h heart rate (HR) monitoring (flex-HR method) and physical activity level (PAL) calculation was based on BMR. Energy, protein and fat intakes were measured by weighing food on a single day. Urban subjects were heavier and taller than their rural counterparts; significant differences were found in stature in men (P < 0.05) and body weight in women (P < 0.05). Urban subjects had longer sedentary periods (HR < or = flex-HR) and shorter active periods (HR > flex-HR) than rural subjects. Consequently, the former had lower TEE and PAL than the latter; significant differences were found in women (TEE, P < 0.05, PAL, P < 0.01) but not in men. Total daily energy intake and TEE were well balanced (<7 %) in all groups, whereas protein and fat intakes were considerably higher in urban subjects than rural subjects. Reduced PAL and increased fat intake by urban dwellers may increase the risks of obesity and chronic degenerative diseases.

Adult↗

PubMed2001

Nutrient intake among female shift workers in a computer factory in Japan.

Based on a 4-day questionnaire survey for all meals and snacks consumed by female workers in a computer factory in Japan, consisting of 44 daytime workers and 93 weekly-rotating shift workers (of whom 47 and 46 were engaged in, respectively, early-shift work and late-shift work during the survey week), the present study aimed to clarify the effects of shift work on their nutrient intakes in association with food consumption patterns. Their dietary intakes for 3 working days and an off day were assessed by self-registered food consumption records with the aid of a photographic method, and intakes of energy, protein, fat, carbohydrate, calcium and iron were estimated. The inter-group differences were prominent in the working days. The shift workers, particularly the late-shift workers, took smaller amounts of energy and nutrients than the daytime workers, implying that the former group's nutritional status has been worsened, judged from the recommended dietary allowance for Japanese. Their inadequate nutrient intake was due to lower meal frequency and poor meal quality, both of which were conditioned by shift work.

Adult↗

PubMed2001

Variation in malaria endemicity in relation to microenvironmental conditions in the Admiralty Islands, Papua New Guinea.

For 197 adults and adolescents in four villages of three small islands in the Admiralty Islands, Papua New Guinea, antimalarial antibody titers were examined using the indirect fluorescent antibody test (IFAT) and malaria parasites were detected by the microtiter plate hybridisation (MPH) method using polymerase chain reaction (PCR) technique. The parasite rate (either Plasmodium falciparum or P. vivax, or both) averaged 39.2%, varying from 31.1% to 44.8% among the four villages due to natural and artificial microenvironmental conditions related to breeding sites of mosquitoes (Anopheles farauti). The lack of flat zones owing to geomorphological formation contributed to the lowest parasite rate in the extremely small island. However, human-modified environments such as a wet-land (naturally formed but artificially reformed) and an open well played significant roles in other inter-village differences. The present findings imply significant roles of microenvironment in diversified malaria prevalence and suggest some ways of mitigation of malarial hazards.

Adolescent↗

PubMed2001

Males in rural Bangladeshi communities are more susceptible to chronic arsenic poisoning than females: analyses based on urinary arsenic.

Spot urine samples were collected from the inhabitants of two rural communities in northwestern Bangladesh. We compared arsenic levels in the urine samples ([As](u); n = 346) with those in water from tube wells ([As](tw); range < 1-535 microg/L; n = 86) on an individual basis. The small variation of [As](u) within subjects and highly positive correlation with [As](tw) indicate that [As](u) is a useful indicator of exposure. Analyses of [As](u) showed that creatinine correction was necessary, that [As](u) only reflected recent exposure, and that there were substantial interindividual differences for a given [As](tw) level. To evaluate the toxic effects of arsenic exposure, we constructed a system for rating skin manifestations, which revealed distinct sex-related differences. Comparison of males and females in the same households confirmed that skin manifestations were more severe in the males, and in the males of one community a dose-response relationship between [As](u) and the degree of skin manifestation was evident. The results of this study indicate that [As](u) in spot urine samples can be used as an exposure indicator for As. They suggest that there might be sex-related, and perhaps community-related, differences in the relationship between [As](u) and skin manifestations, although several confounding factors, including sunlight exposure and smoking habits, might contribute to the observed sex difference. The existence of such differences should be further confirmed and examined in other populations to identify the subpopulations sensitive to chronic arsenic toxicity.

Adult↗

PubMed2000

Establishment of efficient reaggregation culture system for gene transfection into immature T cells by retroviral vectors.

To overcome low efficiency of retroviral infection into immature T cells, we modified reaggregation fetal thymus organ culture by closely packed co-culture with virus-producing cells (VPC). The viral vector was constructed in chimeric vector, pMX, with IRES and tailless-rat CD2 as a surface marker of infected cells. A rearranged TCR beta gene (Vbeta8.2) was further inserted into the construct for investigating effect of the introduced gene in T cell development. Using this system, we succeeded to transfer the viral vector into immature thymocytes at a remarkably higher efficiency compared to conventional methods using medium containing retrovirus. Moreover, the introduced TCR beta gene was expressed on thymocytes of RAG2-deficient mice to induce in the transition of CD4-CD8- double-negative (DN) into CD4+CD8+ double-positive (DP) cells by transducing beta-selection signaling. Thus, our modified reaggregation culture system is useful for studying the molecular mechanism of T cell development due to a highly efficient gene transfer into immature T cells.

Animals↗

PubMed2000

Basal metabolic rate and energy costs at rest and during exercise in rural- and urban-dwelling Papua New Guinea highlanders.

OBJECTIVE: (1) To evaluate inter-individual variations, regional and sex differences in the basal metabolic rate (BMR) and related variables; (2) to compare measured BMR with estimated BMR using predictive equations; and (3) to examine the net mechanical efficiency (NME) in step tests. DESIGN: BMR and energy costs at rest and during step tests were measured by the Douglas bag technique of indirect calorimetry. NME was calculated from BMR and energy costs of step tests. SETTING: Rural villages under subsistence agriculture and urban settlements under cash economy. SUBJECTS: Adult males and females (n=33) including 16 rural villagers and 17 urban migrants. INTERVENTIONS: Step exercise test. RESULTS: There were significant regional differences in BMR (per body weight) in both sexes. The BMR predicted by Schofield equation correlated with the measured BMR (-1 to+3%), while the BMR predicted by Henry and Rees equations under-estimated the measured BMR by 6-11%. NME was higher in urban subjects with larger body size than in rural subjects for both sexes, albeit insignificantly. NME tended to be higher with increased stepping level in both sexes. CONCLUSIONS: Urban migrants had lower BMR than rural dwellers, and the BMR predicted by Schofield equation correlated with the measured BMR in both sub-groups.

Adolescent↗

PubMed2000

Teratologic studies on rat perinates and offspring from dams treated with ethylnitrosourea (ENU).

Ethylnitrosourea (ENU), a well known DNA alkylating agent, induces anomalies in the central nervous system (CNS), craniofacial tissues, limbs and male reproductive organs. Recently we clarified that excess cell death caused by apoptosis occurred in these organs and tissues of rat fetuses from dams treated with ENU at day 13 of gestation (GD13). In this study, we examined fetuses at GD21 and offspring at 10 weeks of age after ENU administration to pregnant rats at GD13 in order to clarify the relationship between ENU-induced apoptosis in the fetal tissues and teratogenicity of ENU. Severe intrauterine growth retardation was observed in the ENU group, and the body weight of the offspring in the ENU group was significantly lower than that of the control group throughout the experiment. In addition, a high incidence of microencephaly, ectrodactyly and curved caudal vertebrae was observed in the offspring from dams treated with ENU at GD13. Judging from the results of our previous and present studies, it was strongly suggested that ENU-induced apoptosis in rat fetal tissues may play an important role in the induction of anomalies in the corresponding tissues.

Abnormalities, Drug-Induced↗

PubMed2000

Analysis of HLA-DRB1 polymorphism in the Gidra of Papua New Guinea.

The genetic structure of the Gidra-speaking population inhabiting 13 villages in Papua New Guinea was investigated, based on the analysis of HLA-DRB1 polymorphism. Nei's fixation indices (F(IS), F(IT), and F(ST)) showed that the Gidra villages were genetically differentiated. The genetic distances significantly correlated with the geographic distances among the 13 villages. Thus, it is likely that a low intervillage migration rate has been maintained since the Gidra community was established. Correspondence analysis revealed that the Gidra, who belong to non-Austronesian-speaking groups, are genetically located at the intermediate point between the Aboriginal Australian groups and the Austronesian-speaking groups. Moreover, the HLA-DRB1*0802 allele, which has been observed in only two Polynesian groups (Austronesian-speaking groups) of Oceanian populations, was also found in the Gidra. These results suggest that the admixture of Austronesian and indigenous non-Austronesian groups beyond the linguistic boundary occurred partly in Papua New Guinea before Austronesian groups spread to the Pacific.

Black People↗

PubMed1999

Daily time budgets of long-distance commuting workers in Tokyo megalopolis.

In Tokyo Megalopolis, long-distance commuting between residences in the suburbs and work places in the centre of the city was examined. Using a questionnaire, heads of household in two suburbs were asked about the influences of long commuting hours on their daily time budgets. The results showed that on workdays, the workers who spent longer commuting rose and left home for work earlier, and came back home and retired later; accordingly, both time spent on in-home activities on workdays and hours slept on the day before a workday were shorter. Comparison of time budgets between the subjects who work 5 and 6 days per week revealed more vulnerable influences of long commuting hours in the former than the latter. The expected health consequences of these findings are discussed from a biosocial/human ecological viewpoint.

Adult↗