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Biomedical subjects

A Okayama

Publications and source records attributed to A Okayama.

At least 109 records · Page 6Linked to original sources
PubMed1993

Heterosexual transmission of human T cell leukemia/lymphoma virus type I among married couples in southwestern Japan: an initial report from the Miyazaki Cohort Study.

To identify factors that may modify the heterosexual transmission of human T cell leukemia/lymphoma virus type I (HTLV-I), 534 married couples enrolled in the Miyazaki Cohort Study between November 1984 and April 1989 were studied: 95 husband HTLV-I-seropositive (H+)/wife seropositive (W+), 33 H+/W-, 64 H-/W+, and 342 H-/W-. After 5 years of follow-up, seven seroconversions occurred and clustered significantly among serodiscordant pairs (relative risk [RR] = 41.2); the rate of transmission was 3.9 times higher if the carrier spouse was male (P = .19). Among H+/W- couples, husband's age > or = 60 years strongly predicted seroconversion in the wives (RR = 11.5). All 4 carrier husbands whose wives seroconverted had HTLV-I titers > or = 1:1024 (P = .04) and were anti-tax antibody positive (P = .06). In cross-sectional analysis, total parity also was independently associated with wife's serostatus but only length of marriage with husband's. Overall, sexual transmission of HTLV-I was primarily from older infected husbands to their wives, with husbands' viral status being an important factor.

Adolescent↗
PubMed1993

Latency of the Achilles tendon reflex for detection of reduced functions of the peripheral nervous system in workers exposed to lead.

The latency of the soleus muscle potential, evoked by a tap of the Achilles tendon, was used in the mass assessment of healthy male workers exposed to lead. Three groups were studied: a control, a low exposure, and a high exposure group. Mean blood lead concentrations were 9.3, 19.2, and 53.1 micrograms/100 ml respectively. Latencies were adjusted for age and height and then compared among the three groups. The mean corrected latency of the high exposure group showed a 4% increase compared with the other two groups (p < 0.01). The latencies of the other two groups showed no between group differences. These results were consistent with previous neurophysiological studies done by many researchers on workers exposed to lead. They suggested that nerve conduction velocities decreased from 3 to 13% among workers whose mean blood lead concentrations were more than 30 micrograms/100 ml. The method was simple, time conserving, non-invasive, and non-aversive, and provided a quantitative measure of the nerve conduction velocities of peripheral nerves. Thus it may be useful for early detection of occupationally related impairment of peripheral nerves.

Achilles Tendon↗
PubMed1993

[A comparative study of the health conditions of elderly people living alone, elderly couples and the bedridden elderly at home in a rural area of Shiga Prefecture: special reference to morbidity rate and blood pressure, electrocardiograph and blood examination data].

For the purpose of obtaining basic data and for establishing a support system for elderly people with various health and social problems, a population survey was performed in 1990 to investigate the health and living conditions of elderly people living alone, elderly couples and the bedridden elderly in the town of Shigaraki, Shiga Prefecture. A total of 275 subjects (103 male, 172 female) 65 years of age and over were surveyed. The participation rate in this survey was 88.1%. Analysis of health conditions (morbidity rate, blood pressure, electrocardiograph and blood examination data) of elderly people living alone, elderly couples and the bedridden elderly produced the following: 1) Stroke was the main cause of being bedridden in men, while in women, bone and joint disease, especially fracture, was the main cause. 2) The combined prevalence of hypertension and borderline hypertension in elderly people living alone, elderly couples and the bedridden elderly was over 50%. The bedridden elderly had a lower prevalence than elderly people living alone and elderly couples. 3) Men in all of the above mentioned life styles, had a higher tendency of showing ECG abnormalities than women. The tendency for major ECG abnormalities was high for bedridden elderly, both male and female, with the tendency for men being higher. 4) In bedridden elderly, a tendency of higher prevalence of anemia, in both male and females, lower total serum cholesterol and triglyceride in males compared to elderly people living alone and in elderly couples, was observed.

Activities of Daily Living↗
PubMed1993

[Factors influencing self-registration in a bone-marrow bank: analysis of data from a population survey in Shiga Prefecture].

A population survey of awareness and attitudes regarding a bone-marrow bank was carried out in 19 cities and towns of Shiga prefecture in July 1991, to identify factors that would promote donor self-registration among the general population. The survey involved 832 residents (416 men and 416 women) selected as follows: Each social welfare commissioner of the cities and towns selected a total of eight residents, one male and one female from each of 4 age groups (20-29, 30-39, 40-49 and 50-59 years old). The questionnaires were distributed and collected by the social welfare commissioners with an overall response rate of 97.4%. Subjects answered questions regarding their experience and desire to participate in social volunteer activities, knowledge about bone-marrow banks, their perception of it's necessity, and whether they would participate in a bone-marrow bank, etc. A total of 25.9% of male and 20.6% of female subjects stated they had a desire to register in a bone-marrow bank. From the result of multiple regression analysis, the characteristics of those who showed interest in registration in a bone-marrow bank included having heard of the bone-marrow bank, experience in social volunteer activity, experience in blood donation, knowledge of bone-marrow transplantation and living in a town where need for establishment of a bone-marrow bank was widely discussed among residents. In the promotion of the idea of a bone-marrow bank, the role of motivating people to participate in voluntary blood donation and other social volunteer activities appears to be important.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

High HTLV-I proviral DNA level associated with abnormal lymphocytes in peripheral blood from asymptomatic carriers.

The level of proviral DNA in peripheral blood mononuclear cells from a representative group of asymptomatic HTLV-I carriers in Miyazaki district, an HTLV-I endemic area in Japan, was determined by a single-cycle polymerase chain reaction method (PCR). Of 217 subjects, 26% had a high level of proviral DNA, 43% a medium level, 18% a low level, and 13% an undetectable level. In the high-DNA group, 60% had at least 0.6% abnormal lymphocytes on peripheral blood smears, significantly higher than in those with low DNA levels (19%). This association was present for men of all ages and for women under 55. Men were more than twice as likely to have abnormal lymphocytes as well as high levels of proviral DNA. These differences may reflect different host responses to the virus by sex or by the time or route of infection. This study supports the utility of PCR for molecular screening in epidemiologic studies of the natural history of HTLV-I, and may lead to the identification of those carriers who are at greatest risk of developing HTLV-I-induced malignancy.

Age Factors↗
PubMed1992

A cross-sectional study on the brainstem auditory evoked potential among workers exposed to carbon disulfide.

In order to clarify the chronic effect of carbon disulfide (CS2) on the central nervous system (CNS), the brainstem auditory evoked potential (BAEP) was measured in spinning workers exposed to CS2 in a viscose rayon manufacturing factory and unexposed workers in Japan. Workers exposed to CS2 were divided into three groups according to length of exposure: current spinning workers with an exposure duration of more than 240 months (L group, n = 34), current spinning workers with an exposure duration of 24-84 months (S group, n = 25), and former spinning workers with an exposure duration of more than 120 months (R group, n = 16). Unexposed controls were selected from workers in a nylon filament factory using the same criteria (N group; n = 40). BAEP records were analyzed based on the latencies of three main components (I, III, V) and interpeak latencies (I-III IPL, III-V IPL, I-V IPL). Latencies of component V, III-V IPL, and I-V IPL in the L group were significantly greater (P < 0.01, P < 0.05, P < 0.05, respectively). The significantly, higher III-V IPL in the L group suggested that in humans, chronic exposure to CS2 involves the auditory ascending tract in the brainstem. Recovery from this neurotoxic effect is apparently possible, as the BAEP parameters in the R group were not significantly higher than those of the N group despite the long previous CS2 exposure of the R group.

Adult↗
PubMed1992

Changes in auditory brainstem response in rats chronically exposed to carbon disulfide.

The chronic effect of carbon disulfide (CS2) on the central nervous system (CNS) was studied by examining auditory brainstem responses (ABRs) in female rats (Jcl Wistar) exposed to 200 ppm or 800 ppm CS2 by inhalation, 6 h a day, 5 days a week, for 15 weeks. Two modes of ABRs evoked by clicks at 61 and 96 dB sound pressure levels (61 dB-ABR and 96 dB-ABR) were recorded during the exposure and for 6 weeks afterwards. Three main components (I, III and V) of ABRs were analyzed from the latencies and differences between latencies of them (interpeak latencies, IPL I-III, IPL III-V and IPL I-V). The latencies of the three components and IPLs of 96 dB-ABR in rats group exposed to 800 ppm of CS2 were significantly delayed during the exposure period. The delay of latency of component V and IPL III-V and I-V tended to increase with exposure time. At 61 dB-ABR, the changes in the latency of component V, IPL III-V and I-V resembled those at 96 dB-ABR. For the rats group exposed to 200 ppm CS2, the latency of component I, IPL III-V and I-V at 96 dB-ABR were delayed significantly but transiently during the exposure period. For both groups, recovery from the latencies of the three components and IPLs of ABR was observed by the end of the recovery period. The delayed latencies of ABR observed in rats exposed to 800 ppm CS2 suggested a conduction dysfunction in the brainstem due to CS2 exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Sensitivity of polymerase chain reaction assay for Rickettsia tsutsugamushi in patients' blood samples.

We developed a nested polymerase chain reaction (PCR) method to detect Rickettsia tsutsugamushi (R. tsutsugamushi) DNA and determined its sensitivity. Primers were selected from the DNA sequence of the 58-kDa group-specific antigen gene of the Karp strain. The target sequence of rickettsial DNA was detectable as the band corresponding to 88 bp in 1.0 microgram of the DNA extracted from BS-C-1 cells infected with R. tsutsugamushi. Rickettsia-specific bands were observed not only for the homologous Karp strain, but also for four heterologous strains: two other reference strains (Gilliam and Kato) and two prototype strains prevalent in Miyazaki district (Irie and Hirano). The minimum copy number detectable by this method was estimated to be five rickettsiae. All of nine peripheral blood mononuclear cell samples from patients with tsutsugamushi disease who were seen 2-11 days after disease onset tested positive for rickettsial DNA. The PCR assay method presented here could be a specific diagnostic tool for tsutsugamushi disease, especially in its early acute stage.

Adult↗
PubMed1992

Successful graft of HTLV-I-transformed human T-cells (MT-2) in severe combined immunodeficiency mice treated with anti-asialo GM-1 antibody.

To develop an experimental model of adult T-cell leukemia/lymphoma in small animals, severe combined immunodeficiency (SCID) mice treated with anti-asialo GM-1 antibody were inoculated with MT-2 cells, a cell line transformed by the human T-cell leukemia virus (HTLV-I). Three mice injected with 4 x 10(7) cells subcutaneously or intramuscularly developed tumors at or near inoculation sites. Immunofluorescent antibody (IFA) staining for HTLV-I structural protein, p19, revealed the specific antigen in the cytoplasm of most cells from tumors and the DNA signals of HTLV-I proviral DNA were also positive in cellular DNA by polymerase chain reaction assay with HTLV-I tax gene primers, SK43/SK44. The MT-2 cells did not invade in mouse organs.

Animals↗
PubMed1992

Which postoperative combined therapy results in the best prognosis: radiochemocytokine therapy or aggressive chemotherapy?

The recurrence of esophageal cancer involving regional nodes, even in patients who have undergone curative surgery, often takes place within three years after surgery. Thus, a new multidisciplinary treatment including cytokines or aggressive chemotherapy with active nutritional support to improve the prognosis in cancer of the thoracic esophagus has been adopted.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Determinants of HTLV-1 seroprevalence in Miyazaki Prefecture, Japan: a cross-sectional study.

To evaluate determinants of the prevalence of human T-cell leukemia virus type I (HTLV-I) antibody positivity in an endemic region, Miyazaki Prefecture, Japan, demographic and serologic data were collected on 7,055 individuals consecutively seen at Miyazaki City Health Promotion Center between September 1983 and December 1984. The overall HTLV-I seroprevalence was 8.5%; age and gender distributions of HTLV-1 antibody positivity were consistent with previous findings for endemic populations. The prefecture could be divided into two geographic areas based on seroprevalence: high prevalence (12.1%) in the southwest and medium prevalence (6.6%) for the rest of the prefecture. Current occupation in fishing, forestry, or livestock raising significantly correlated with HTLV-1 seropositivity [relative risk (RR) = 3.0, 2.5, 2.0, respectively]; farming also was associated but only in the medium prevalence region (RR = 1.3; p = 0.06). For a subset of 157 HTLV-I-positives and 175 negative controls screened for antibodies to the toxoplasmosis organisms, toxoplasma exposure was not significantly associated with HTLV-I infection. In this endemic Japanese population, both geographic and sociologic factors characterized the distribution of HTLV-I seroprevalence, reflecting transmission patterns and historical duration of the infection.

Adolescent↗
PubMed1991

Unusual pattern of antibodies to human T-cell leukemia virus type-I in family members of adult T-cell leukemia patients.

Detection methods for the human T-cell leukemia virus type-I (HTLV-I) for blood screening and diagnosis generally rely on antibody tests that use the structural proteins of HTLV-I as antigen. We have found an unusual pattern of antibody reactivity among people who are at high risk of HTLV infection due to being a family member of an adult T-cell leukemia (ATL) patient: a specific antibody reaction exclusively directed to the HTLV regulatory protein tax, and not to the HTLV-I structural proteins. Sera from 7 of 82 (8.5%) structural antibody-undetectable family members of ATL patients had the anti-tax reactivity. Two seroconverters were observed. One seroconverter a healthy resident of Miyazaki, tested negative for structural antibody, but positive for tax antibody. Two years later she tested positive for both. The other seroconverter, an Israeli hemophiliac, tested negative for both antibodies, but converted to tax antibody-positive/structural antibody-negative. The HTLV-I tax-only antibody profile was also observed in sera sets from two other populations at risk for HTLV infection, human immunodeficiency virus-1-infected patients at the Bronx-Lebanon Hospital in New York and Israeli hemophiliacs. DNA samples from lymphocytes of four individuals with antibody reactivity only to HTLV-I tax were tested in polymerase chain reaction experiments; no HTLV-I or -II DNA was detected.

Animals↗
PubMed1991

Sexual transmission of human T-cell leukemia virus type I associated with the presence of anti-Tax antibody.

The tax gene product (Tax protein) of human T-cell leukemia virus type I (HTLV-I) is a specific transcriptional activator of the viral long terminal repeat sequence and is essential for the replication cycle of the virus. To elucidate the relationship between the presence of anti-Tax antibody and the transmission of the viral infection, annual consecutive serum samples from married couples serologically discordant or concordant for HTLV-I were examined. These included 5 individuals whose spouses seroconverted during this 5-year follow-up study period. The samples were tested by a Western blot assay using a recombinant Tax protein as the antigen. The results showed that 24 of 32 (75%) men in the concordant couples (both husband and wife were HTLV-I carriers) had anti-Tax antibody, while only 5 of 18 (27.8%) men in the discordant couples (husband was carrier and wife was seronegative to HTLV-I) were positive for anti-Tax antibody (P = 0.0012). Furthermore, all spouses of the 5 seroconverters (4 women and 1 man) had anti-Tax antibody, while only 23 of 46 (50%) age-matched randomly selected HTLV-I carriers from the discordant-couple group had anti-Tax antibody. When the data were analyzed by gender, all husbands of the female seroconverters had anti-Tax antibodies, which was significantly higher than the prevalence of anti-Tax antibodies in men who did not transmit the virus to their spouses during the follow-up period (P = 0.017). In addition, antibody reactivity to other HTLV-I antigens (including Env gp46, transmembrane protein gp21, and Gag p19 and p24) were examined. The results indicated no significant differences between the prevalence of antibody reactivity to any of the antigens in the spouses of the seroconverters and the reference group. We conclude that the presence of anti-Tax antibody in men may indicate a high risk of viral transmission to their wives via heterosexual routes.

Agglutination Tests↗
PubMed1991

Alterations in the metabolism of serotonin and dopamine in the mouse brain following a single administration of allylnitrile, which induces long-term dyskinesia.

The effects of allylnitrile (ALN), which induces a long-term dyskinesia in mice, on the metabolism of serotonin (5-HT) and dopamine (DA) were studied after a single administration. One day after injection, ALN produced a significant increase in the levels of 5-HT, 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA): 5-HT in the brain cortex, medulla oblongata plus pons, hypothalamus and midbrain; 5-HIAA in the cortex, medulla oblongata plus pons, striatum, hypothalamus and midbrain; the ratio of 5-HIAA/5-HT in the medulla oblongata plus pons, striatum and midbrain; HVA in the cortex and midbrain. These changes were not seen 10 and 35 days after injection when the animals were showing behavioral abnormalities. The present findings suggest that changes in 5-HT and DA metabolism are involved in the appearance of the dyskinetic syndrome.

Administration, Oral↗
PubMed1991

High incidence of antibodies to HTLV-I tax in blood relatives of adult T cell leukemia patients.

Adult T cell leukemia (ATL) is caused by the human T cell leukemia virus type I (HTLV-I). Although the mechanisms of the leukemogenic process are unknown, the tax gene may have a role in this process. Because clustering occurs with HTLV-I and ATL, members of ATL families were examined for antibodies to the tax protein and compared with matched HTLV-I-positive blood donors. To investigate the antibody response to this protein, a plasmid, pBHX-4, was constructed to express a recombinant tax protein (r-tax). For ATL patients and their HTLV-I antibody-positive blood relatives, the rate of seroreactivity with the r-tax protein was 67.3% (35/52), compared with 51.6% (97/188) for HTLV-I antibody-positive control blood donors (P less than .05). The difference between direct offspring of ATL patients and matched HTLV-I blood donors was even greater (84.2% [16/91] vs. 44.2% [42/95]; P less than .005). Thus, tax antibody positivity in direct offspring of ATL patients may reflect differences in time or route of HTLV-I infection. Alternatively, it might reflect genetic differences in host susceptibility or virus strain.

Adolescent↗
PubMed1991

Polymerase chain reaction analysis of defective human T-cell leukemia virus type I proviral genomes in leukemic cells of patients with adult T-cell leukemia.

Human T-cell leukemia virus type I (HTLV-I) is the etiologic agent of adult T-cell leukemia, and the clonally derived leukemic cells all contain proviral genomes. Polymerase chain reaction with a variety of primers which span the HTLV-I genome was used to determine that a significant fraction of patients (at least 32%) carry deleted viral genomes in their leukemic cells. The pX region of the HTLV-I genome encoding the regulatory genes tax and rex was preferentially retained. The fact that the tax coding region was retained provides supporting evidence that the tax protein contributes to leukemogenesis in vivo. The reasonably high fraction of patients with adult T-cell leukemia carrying deleted genomes in their tumor cells suggests that the deletions have a role in leukemogenesis.

Adult↗