Biomedical subjects
Publications and source records attributed to H Ushijima.
Rotavirus was examined in 818 diarrheal stool samples collected in Karachi, Pakistan, from 1990 to 1997. Rotavirus was detected in 112 samples (13.7%). The predominant serotypes were G1 and G4 and G3 was not detected. The predominant type changed between years. Rotavirus was found in all seasons and most infections were found in children aged less than 2 years.
An epidemiological survey of maternal child-rearing behaviors was conducted in the rural minority areas of Yunnan, China. An interview of 2019 rural mothers of Hani, Yi, Hui, Miao, and Han and 544 urban mothers with children younger than 7 years of age showed that 51.7% of these rural mothers placed their infants in swaddling clothes. In the rural sample, exclusive breastfeeding occurred at frequency rates of 76.7% and 34.2% during 3 and 6 months postpartum, respectively. Maternal training and playing behaviors were reported less frequently, whereas physical punishment for children's misbehavior was more commonly found in the child-rearing behavior of rural mothers. Maternal child-rearing behaviors differed significantly among ethnic groups as well as between urban and rural areas. Maternal child-rearing behaviors were significantly associated with maternal education level, family type, family income, maternal age at delivery, and number of children in the family. Children's gender had no significant association with maternal child-rearing behaviors.
In addition to the serotype-specific primers described previously (1 to 7), a new serotype 8-specific primer has been designed, allowing detection of all astrovirus serotypes. A total of 1,382 diarrheal stool samples in 5 regions in Japan were examined by reverse transcription-polymerase chain reaction (RT-PCR). The incidence of astrovirus infection in all 5 regions was 5.9% (82 of 1,382 samples) and infection occurred mainly from November to April. Serotypes 1, 3, and 4 were detected in 66, 14, and 2 of the 82 positive samples, respectively. None of the other serotypes was detected. The highest detection rate was from 0 to 1 year old, 39.0%, and the next highest was from 1 to 2 years old, 34.1%. The primers provide a useful approach for study of the epidemiology of astroviruses.
Sulfated colominic acid exhibited suppressive effects on SA11 (simian rotavirus)- and MO (human rotavirus)-infections, but not on Wa (human rotavirus)-, Sabin 1 (poliovirus 1)-, and Nancy (coxsackie B3 virus)-infections, in vitro. The infection of SA11 was found to be inhibited by mixed treatment and early posttreatment with sulfated colominic acid, but not by pretreatment, by plaque assay and multiple growth assay. The results were confirmed by the infectivity titer, RNA polyacrylamide gel electrophoresis, and electron microscopic analysis. The mechanism of the suppressive effect was suggested to be adsorption inhibition at an early stage of the infection.
Astroviruses are small RNA viruses associated with pediatric gastroenteritis. A latex agglutination (LA) test is more convenient and rapid than electron microscopy, enzyme immunoassay (EIA) and reverse transcription-polymerase chain reaction (RT-PCR) for detection of astroviruses in stool specimens was developed by using polyclonal antibody against cultured serotype 1 astrovirus, and tested on astrovirus positive- and negative- samples collected between 1985 and 1993 in Ehime, Japan. Cultured serotype 1 astrovirus was detected by the LA test, but serotype 2, 3, 4, 5, 6, and 7 viruses could not be detected, although they yielded high titer of the viruses. When tested on the 27 clinical samples, all 8 serotype 1 astroviruses determined previously by EIA were positive by the LA test, however, 9 other serotype astroviruses and 10 astrovirus negative-samples were all negative. PT-PCR was found to be the most sensitive followed by EIA and LA test. Further development of LA test with other serotypes is necessary.
BACKGROUND: Child growth retardation and malnutrition remain a matter of uttermost public concern in economically disadvantaged areas of China. The present study aimed to estimate the prevalence of protein-energy malnutrition with various anthropometric indices and examine its correlates in a large sample of poor rural minority children. METHODS: A total of 2019 children under 7 years of age belonging to the Hani, Yi, Hui, Miao ethnic minority groups and the Han major group were drawn from four poor rural minority counties in the Yunnan Province of China. Well-trained investigators completed child physical measurements and maternal interviews. Protein-energy malnutrition was defined as being underweight (weight for age), wasting (weight for height) and stunting (height for age) on the basis of reference data from the National Center of Health Statistics (NCHS)/World Health Organization (WHO). RESULTS: The respective prevalence of moderate and severe protein-energy malnutrition was 15.8 and 3.1% for underweight children, 31.8 and 19.2% for stunting and 0.9 and 0.5% for wasting. Stunting was most common in children aged 2 years. Boys were more likely to suffer from malnutrition. Logistic regression analyses showed that lower family income, lower parental height, belonging to the Miao, Yi and Hani ethnic groups compared with Han and poorer maternal child-rearing behavior significantly increased the risk for stunting of children. CONCLUSIONS: Protein-energy malnutrition is relatively high in the rural minority children of China. Chronic socioeconomic underdevelopment and genetic effects, rather than a severe or immediate lack of food, may lead to protein-energy malnutrition.
BACKGROUND: The promotion of breast-feeding is one of the essential interventions for reduction of infant mortality and improving infant development worldwide. The aim of the present study was to examine the current status of infant feeding and the influences of suspected family sociodemographic characteristics and social support as well as maternal knowledge, attitudes and behaviours in infant feeding since the Baby-Friendly Hospital Initiative was launched in Thailand. METHODS: A total of 221 mother-infant pairs were randomly drawn from six health care centers in Bangkok from 20 April to 1 May 1998. Health care staff, using a structured questionnaire, interviewed the mothers in the health care centers. RESULTS: Most sampled mothers believed that breast milk was the best food for their infants and knew that breast milk had many advantages for infants, mothers and families. Ninety-five percent of mothers breast-fed their infants up to 3 months postpartum, but the prevalence of exclusive breast-feeding was relatively low (62.4%). Multiple logistic regression analyses revealed that the following factors independently increased the risk of mixed or formula feeding during the first 3 months of life: (i) mothers with a full-time job; (ii) grandmothers and other people as the main child caretakers; (iii) mothers who did not have an antenatal plan of exclusive breast-feeding; and (iv) newborns' non-exclusive breast-feeding in hospitals after birth. However, the mother being a housewife, mother as the main child caretaker, an antenatal plan of exclusive breast-feeding and exclusive breast-feeding in hospital were more likely to improve exclusive breast-feeding. CONCLUSION: The prevalence of exclusive breast-feeding was relatively low. Antenatal plans for exclusive breast-feeding and newborn feeding type in hospital after birth may play key roles in the duration of exclusive breast-feeding. These findings suggest the importance of strengthening implementation of the Baby-Friendly Hospital policy and prenatal health education regarding breast-feeding.
We have determined that the tolerance of in vitro matured/in vitro fertilized (IVM/IVF) bovine embryos to cryopreservation at the pre-morula stage can be improved by removal of cytoplasmic lipid droplets by centrifugation. Nucleus transfer was also performed using cryopreserved, delipated (lipid droplets removed) 8- to 16-cell-stage blastomeres of IVM/IVF embryos as donor nuclei. In vitro developmental ability of the delipated embryos to the blastocyst stage (20 of 126) was found to be equal to that of undelipated embryos (35 of 176); and of 53 delipated embryos cryopreserved at the 8- to 16-cell stage, 12 developed into blastocysts in vitro after thawing. On the other hand, only 2 of 43 undelipated embryos and 5 of 59 sham-operated embryos survived (p < 0.05). When blastomeres isolated from cryopreserved, delipated 8- to 16-cell-stage embryos were used for nucleus transfer, 57 of 80 successfully fused with enucleated oocytes, which was significantly lower than the fusion rate obtained with blastomeres of unfrozen, undelipated embryos (93 of 104, p < 0.01). However, the developmental rate to the blastocyst stage for nucleus transfer embryos reconstituted with frozen, delipated blastomeres (9 of 57) was not different from that of the nucleus transfer embryos with unfrozen, undelipated embryos (23 of 93). These results confirm that removal of cytoplasmic lipid droplets from bovine IVM/IVF zygotes allows for successful cryopreservation at the 8- to 16-cell stage and that blastomeres from these embryos can be used as donors of karyoplasts for nucleus transfer.
The entire capsid regions of 12 serotype-4 astroviruses from Japan were sequenced and compared with those of other serotypes. Serotype-4 isolates were divided into two new subgroups. The intrasubgroup nucleic acid and deduced amino acid sequences were quite homologous (more than 93%), but slightly less so between subgroups (almost 85%). However, the serotype-4 sequences differed from those of serotypes 1, 2, 3, 5, 6, 7 and 8 (less than 50%). Determining whether these differences significantly alter the epidemiology and antigenicity will require further investigation.
Sequence analyses of the VP4 and NSP4 genes were performed on twenty human isolates of serotype G3 rotavirus obtained from China and Japan. One isolate from China, CHW17, possessed P[4] genotype VP4 and KUN group NSP4 genes which are associated with G2. One isolate (02/92) from Japan, which was shown to have a wider spacing between RNA segments 10 and 11 by RNA polyacrylamide gel electrophoretic analysis like AU-1, possessed P[9] genotype VP4 and AU-1 group NSP4 genes. The other isolates had P[8] genotype VP4 and Wa group NSP4 genes. While the nucleotide sequence conservation among the G3 VP7 genes was more than 79% (Wen et al, Arch. Virol., 1997, 142: 1481-1489), the conservation of VP4 and NSP4 genes in the same genotypes or groups was more than 85%.
Human rotavirus (HRV) serotypes were studied from diarrheal stool specimens in children in 7 regions of Japan (Sapporo, Tokyo, Maizuru, Osaka, Kagawa, Kurume, and Saga) from 1984 to 1997 by enzyme immunoassay (EIA) with serotype-specific monoclonal antibodies against serotypes 1, 2, 3, and 4. In addition, reverse transcription-polymerase chain reaction (RT-PCR) was conducted for analysis of "others" which included nonserotypable and mixed-serotype rotavirus specimens by EIA. In 3756 rotavirus-positive specimens, serotype 1 was detected in 2649 (70.5%), serotype 2 in 362 (9.6%), serotype 3 in 232 (6.2%) and serotype 4 in 196 (5.2%). Overall, serotype 1 was predominant from 1984 to 1997, although there were a few cases in which serotype 2, 3 and 4 became predominant based on area and year. The frequency of serotype 1 has gradually increased since 1993. Twenty two, 2, 3 and 1 among 57 specimens of "others" by EIA from Tokyo, Maizuru, Sapporo and Kurume in 1995-1996 and 1996-1997 were determined as serotypes 1, 2, 3, and 9 by RT-PCR, respectively.
To elucidate the effect of pregnancy, lactation and weaning on bone mineral density (BMD) in rats, a longitudinal study was done on the same individuals measuring BMD by dual-energy X-ray absorptiometry (DXA) and comparing their profiles with those of nonpregnant controls. Twenty-seven pregnant Wistar rats which had been mated at 11 weeks old (baseline), lactated during the three weeks postpartum period and weaned thereafter. Twenty-four rats of the same age served as nonpregnant controls. BMDs in lumbar spine, distal femur and caudal spine of all rats were measured weekly from 11 to 22 weeks except for the week of parturition (14th week). During pregnancy, BMDs of the three sites increased significantly from the baseline values, but no significant difference was observed in comparison with the control. After parturition and during lactation, BMD of the three sites decreased significantly from the pregnant values and decreased even from baseline values. All the BMD values of the pregnant group were significantly lower than those of the control group. After weaning, BMDs of the three sites increased gradually and caught up to the control group at 22 weeks in the lumbar spine and the femur and at 21 weeks in the caudal spine. In conclusion, pregnancy in itself does not significantly affect maternal BMDs of rats, although the significant bone mineral loss during lactation is not completely restored until at least 5 weeks after weaning.
The scrapie prion protein (PrP(Sc)) has been shown to induce apoptosis of rat cortical neurons in vitro. Here we demonstrate that the toxic effect displayed by PrP(Sc) can be blocked by sulfated colominic acid (polymer of N-acetylneuraminic acid). This compound acts neuroprotectively at a concentration of > or = 0.3 microg/ml when preincubated with the neurons or PrP(Sc). Rat cortical cells also undergo apoptosis after incubation with the HIV-1 coat protein gpl20 in vitro. This effect was abolished also by sulfated colominic acid when preincubated with the cells or gpl20. Addition of 0.3 microg/ml of compound resulted in an increase in cell viability by about 1.6-1.9-fold compared to cultures incubated for 18 h with 30 ng/ml of PrP(Sc) or 20 ng/ml of gpl20 alone (containing about 40% viable cells). Sulfated colominic acid does not act as antagonist of NMDA receptor channels at concentrations of up to 3 microg/ml when co-administered with 100 microg/ml of NMDA. It displayed a strong cytoprotective effect on human T lymphoblastoid CEM cells exposed to HIV-1; a 50% protection occurred after preincubation of the cells with 0.43 microg/ml of compound. At the same concentration, the compound caused an inhibition of HIV-1-induced syncytium formation. Sulfated colominic acid may be a promising compound for treatment of dementia caused by PrP(Sc) and HIV-1 infections.
Co-stimulatory signals mediated by the interaction of B7-1/B7-2 with CD28 are important for the activation of CD4+ T cells stimulated with antigen on antigen-presenting cells. There are controversies about the expression and function of B7-1/B7-2 on CD4+ T cells. The aim of this study was to analyze the expression of B7-1/B7-2 on naive and memory CD4+ T cells and the co-stimulatory function in the activation of naive CD4+ T cells stimulated by TCR ligation. Present results indicate that memory CD4+ T cells express B7-2 molecules on their surface, whereas naive CD4+ T cells do not. Neither memory nor naive CD4+ T cells expressed B7-1 molecule on their surface, although B7-1 mRNA was faintly expressed in memory T cells. B7-2 molecules expressed on memory T cells co-stimulated CD4+ naive T cells stimulated with plate-coated anti-CD3 to produce IL-2. Naive CD4+ T cells were shown to express B7-2 after co-stimulation with B7-2 and TCR ligation, because the naive T cells stimulated with anti-CD3 and B7-2CHO expressed B7-2 on their surface, although it remained to be studied whether the co-stimulation with B7-2 directly induced B7-2 expression on naive T cells. Our present results indicate that memory CD4+ T cells play some role in the activation of naive CD4+ T cells through the co-stimulation with B7-2 molecules.
Human standard astroviruses, serotypes 1 to 7, and 35 Japanese isolates were typed by reverse transcription and polymerase chain reaction (RT-PCR) with serotype-specific primers for the first time. The results were identical with those obtained by enzyme immunoassay with serotype-specific polyclonal antibodies, a method which has already been reported. RT-PCR with serotype-specific primers is useful for epidemiological studies of astroviruses where serotype-specific polyclonal antibodies are not available. Two parts of the capsid region, N terminus and C terminus, were sequenced. Serotypes differed in those regions. The N terminus differed less than the C terminus between serotypes. Both the N terminus and C terminus were similar intraserotypically with the exception of serotype-4 isolates which could be divided into A and B subgroups on the basis of their C terminus sequences, which were not known previously.
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We have previously reported that the growth of lymphocytes and tumor cells with lymphocyte lineage was strongly inhibited by a part of cloned macrophage hybridomas. This growth inhibition was accomplished by cell-to-cell contact and found to be attributed to lipid-like molecule(s) in a macrophage hybridoma cell membrane fraction. Instead of macrophage hybridomas, in the present study we utilized splenic adherent cells (SACs) that had been stimulated with IFN-gamma to see whether they inhibited tumor cell growth or not. The results demonstrated that IFN-gamma-stimulated but not unstimulated SACs showed a significant growth inhibition of BW-5147 tumor cells. This growth inhibition was not mainly mediated by prostaglandin E2 secreted from macrophages, since the inhibition was not reduced in the presence of indomethacin. Furthermore, as was reported previously in the case of macrophage hybridomas, the inhibitory activity resides in a lipid fraction of IFN-gamma-stimulated SAC membrane.
We have previously reported that a lipid molecule in the membrane fraction of cloned macrophage hybridomas inhibited the growth of lymphocytes and several tumor cell lines. In this study, the inhibitory lipid molecule in the membrane fraction of macrophages was analyzed by thin-layer chromatography and identified as 25-hydroxycholesterol, a family of oxysterols. This conclusion was confirmed by analysis using gas chromatography-mass spectrometry. In addition, both 25-hydroxycholesterol and the lipid molecule recovered from macrophage cell membrane induced apoptosis of the murine T cell lymphoma, BW-5147. These results suggest that an oxysterol expressed in the macrophage cell membrane may participate in the regulation of cell growth through cell contact.