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Biomedical subjects

N L Young

Publications and source records attributed to N L Young.

At least 37 records · Page 2Linked to original sources
PubMed2000

Lack of association between human immunodeficiency virus type 1 antibody in cervicovaginal lavage fluid and plasma and perinatal transmission, in Thailand.

To determine the association between human immunodeficiency virus type 1 (HIV)-specific antibody and RNA levels in cervicovaginal lavage (CVL) samples and plasma, zidovudine treatment, and perinatal transmission, HIV subtype E gp160-specific IgG and IgA were serially measured in a subset of 74 HIV-infected women in a placebo-controlled trial of zidovudine, beginning at 36 weeks of gestation. HIV IgG was detected in 100% of plasma and 97% of CVL samples; HIV IgA was consistently detected in 62% of plasma and 31% of CVL samples. Antibody titers in CVL samples correlated better with the RNA level in CVL samples than with plasma antibody titers. Zidovudine did not affect antibody titers. Perinatal HIV transmission was not associated with antibody in CVL samples or plasma. HIV-specific antibody is present in the cervicovaginal canal of HIV-infected pregnant women; its correlation with the RNA level in CVL fluid suggests local antibody production. However, there was no evidence that these antibodies protected against perinatal HIV transmission.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Disease progression and survival with human immunodeficiency virus type 1 subtype E infection among female sex workers in Thailand.

This study describes rates and correlates of disease progression and survival among 194 female sex workers in northern Thailand who were infected with human immunodeficiency virus type 1 (HIV-1; 96% with subtype E). The median rate of CD4 T lymphocyte decline (3.9 cells/microL/month), median time from infection to <200 CD4 T lymphocytes/microL (6.9 years), and time to 25% mortality (6.0 years) were similar to those found in studies performed in Western countries before highly active antiretroviral therapy was available to populations infected with HIV-1 subtype B. Mortality rates among women with >100,000 HIV-1 RNA copies/mL were 15.4 times higher (95% confidence interval, 5.2-45.2) than among women with <10,000 copies. Initial CD4 T lymphocyte counts and serum virus load were independently strong predictors of survival. These results can help in assessing the effects of the epidemic in Thailand and in determining the prognoses for individual patients.

Adult↗
PubMed2000

Oral zidovudine during labor to prevent perinatal HIV transmission, Bangkok: tolerance and zidovudine concentration in cord blood. Bangkok Collaborative Perinatal HIV Transmission Study Group.

OBJECTIVES: To evaluate tolerance for the oral administration of zidovudine (ZDV) during labor and measure the resulting ZDV concentrations in umbilical cord blood. DESIGN: A cross-sectional study of women in a placebo-controlled trial of short-course ZDV (twice a day from 36 weeks' gestation until labor and every 3 h during labor) to prevent perinatal HIV transmission in Bangkok. METHODS: Umbilical cord blood was collected. Sixty control specimens and specimens from 372 women (182 in the ZDV group, 190 in the placebo group) were tested for ZDV by radioimmunoassay (lower detection limit < 1 ng/ml). RESULTS: All women in the ZDV group took one or more labor dose, 170 (93%) took their last dose within 3 h of delivery, and only five (3%) experienced nausea or vomiting, a proportion similar to the placebo group. The median concentration of ZDV in the cord blood in the ZDV group was 252 ng/ml (range, < 1-1133 ng/ml); 31 (17%) specimens were less than 130 ng/ml (0.5 microM), the concentration thought to be active against HIV in vitro. Median concentrations were 189 ng/ml in specimens from women taking one or two labor doses, 290 ng/ml in those taking three or four doses, and 293 ng/ml in those taking more than four doses (P < 0.01). The ZDV concentration was not associated with time since the last dose, body weight, or perinatal transmission. CONCLUSION: Oral intrapartum ZDV was feasible and well tolerated. Most ZDV concentrations in the cord blood after oral dosing during labor were at therapeutic concentrations but were lower than those reported after continuous intravenous administration. Although concentrations were not associated with perinatal transmission, these data do not exclude the possibility that intrapartum and neonatal chemoprophylaxis is effective.

Administration, Oral↗
PubMed2000

Measurement properties of the activities scale for kids.

The Activities Scale for Kids (ASK) is a self-report measure of childhood physical disability, that has excellent reliability (ICC = 0.97). The purpose of this study was to assess further the ASK's measurement properties. ASK questionnaires were completed by 200 children with musculoskeletal limitations (mean age, 10.1 years). Rasch analyses confirmed that all items measured the same construct and supported aggregation of a summary score. Validity of the ASK was demonstrated by a correlation of 0.81 (P<0.0001) with parent-reported Childhood Health Assessment Questionnaire scores; a significant difference in scores according to clinicians' global ratings of disability (P<0.0001), and a correlation of 0.92 (P<0.0001) with clinician-observation. The ASK showed minimal ceiling effects, no floor effects, and changed by 1.73 standard deviation units after clinically important change. The ASK is a valid and responsive outcome measure that permits 5- to 15-year-old children physical functioning in the community to be assessed accurately by mail. The quality of this measure will enable clinical studies to measure outcome not only in a way that is relevant to patients, but also in a way that is sensitive to small amounts of change and is practical and inexpensive.

Activities of Daily Living↗
PubMed2000

Canadian Acute Respiratory Illness and Flu Scale (CARIFS): development of a valid measure for childhood respiratory infections.

Although acute respiratory infection (ARI) is the most frequent clinical syndrome in childhood, there is no validated measure of its severity. Therefore a parental questionnaire was developed: the Canadian Acute Respiratory Illness Flu Scale (CARIFS). A process of item generation, item reduction, and scale construction resulted in a scale composed of 18 items covering three domains; symptoms (e.g., cough); function (e.g., play), and parental impact (e.g., clinginess). The validity of the scale was evaluated in a study of 220 children with ARI. Construct validity was assessed by comparing the CARIFS score with physician, nurse, and parental assessment of the child's health. Data were available from 206 children (94%). The CARIFS correlated well with measures of the construct (Spearman's correlations between 0.36 and 0.52). Responsiveness was shown, with 90% of children having a CARIFS score less than a quarter of its initial value, by the tenth day.

Acute Disease↗
PubMed2000

Short-course antenatal zidovudine reduces both cervicovaginal human immunodeficiency virus type 1 RNA levels and risk of perinatal transmission. Bangkok Collaborative Perinatal HIV Transmission Study Group.

Human immunodeficiency virus (HIV) levels in cervicovaginal lavage (CVL) and plasma samples were evaluated in relation to perinatal transmission in a randomized placebo-controlled trial of brief antenatal zidovudine treatment. Samples were collected at 38 weeks' gestation from 310 women and more frequently from a subset of 74 women. At 38 weeks, after a 2-week treatment period, CVL HIV-1 was quantifiable in 23% and 52% of samples in the zidovudine and placebo groups, respectively (P<.001). The perinatal transmission rate was 28.7% among women with quantifiable CVL HIV-1 and high plasma virus levels (>10,000 copies/mL) and 1% among women without quantifiable CVL HIV-1 and with low plasma virus levels (P<.001). A 1-log increase in plasma HIV-1 increased the transmission odds 1.8 and 6.1 times (95% confidence interval, 0.9-3.5 vs. 2.4-15.4) for women with and without quantifiable CVL HIV-1, respectively (P=.03). CVL HIV-1 is an independent risk factor for perinatal HIV-1 transmission.

Cervix Uteri↗
PubMed2000

The reliability and validity of the self-reported patient-specific index for total hip arthroplasty.

BACKGROUND: The Patient-Specific Index is unique in that it reflects how individual patients weigh concerns in rating the outcome of total hip arthroplasty. The Patient-Specific Index was originally administered by an interviewer, which is not always feasible and can be costly. The purposes of the present study were (1) to create a self-reported version of the Patient-Specific Index, (2) to determine the reliability of this new self-reported version, and (3) to determine the relationship between the scores on the new self-reported version and those on the original interviewer-administered version. METHODS: A self-reported version of the Patient-Specific Index was developed, and a pilot test was performed on ten patients. Patients who were scheduled for a total hip arthroplasty or who had recently had a total hip arthroplasty were eligible for the reliability and validity testing. A copy of the new self-reported Patient-Specific Index was mailed to the patients, and they completed it independently. The patients' ratings of the importance and severity of twenty-four concerns prior to total hip arthroplasty were added together to create a summary Patient-Specific Index score. To determine test-retest reliability, patients completed the self-reported Patient-Specific Index a second time, two weeks later. To determine criterion validity, participants also completed the interviewer-administered Patient-Specific Index. RESULTS: Fifty-five patients completed the study. The random-effects intraclass correlation test-retest coefficient was 0.79 (greater than 0.75 represents excellent reliability). The mean Patient-Specific Index scores on the self-reported version and on the interviewer-administered version were 173 and 165 points, respectively (Student t test, p = 0.45). The self-reported Patient-Specific Index was concordant with the interviewer-administered Patient-Specific Index (intraclass correlation coefficient, 0.78). CONCLUSIONS: We concluded that a self-reported version of the Patient-Specific Index, which focuses on the concerns of individuals, is reliable and has criterion validity compared with an interviewer-administered version.

Activities of Daily Living↗
PubMed2000

Human immunodeficiency virus-related tuberculosis and primary drug resistance in Bangkok, Thailand.

SETTING: Central Chest Hospital, a 500-bed referral hospital near Bangkok with a large out-patient department. OBJECTIVES: To determine human immunodeficiency virus (HIV) seroprevalence among patients with pulmonary tuberculosis (TB), and compare HIV-positive and HIV-negative TB patients. DESIGN: From July 1995 through June 1996, a cross-sectional study was conducted of newly registered adults (> or =16 years old) with suspected pulmonary TB. RESULTS: Of 2587 newly registered patients with suspected pulmonary TB, 2019 (78%) received HIV pretest counseling and 1816 (90%) consented to testing. Of these, 364 (20%) were HIV-seropositive. Among 1091 patients with bacteriologically confirmed TB, HIV seroprevalence was 22%. HIV-positive patients were more likely to be young, unemployed, single men and to have a history of injection drug use. HIV-positive patients with first-episode TB were more likely to have Mycobacterium tuberculosis strains resistant to isoniazid (10.9% vs 3.5%; P < 0.001), rifampicin (9.4% vs 2.9%; P < 0.001), and at least isoniazid and rifampicin (multidrug-resistant TB [MDR-TB]; 5.2% vs 0.4%; P < 0.001). CONCLUSIONS: HIV prevalence is high among TB patients at this Bangkok hospital and is associated with drug resistance, including a 12 times higher risk of MDR-TB. These findings underscore the urgent need to assure adherence to complete, effective TB treatment regimens for all patients, including persons who are potentially difficult to manage such as injection drug users.

AIDS-Related Opportunistic Infections↗
PubMed1999

Clinical presentation of hospitalized adult patients with HIV infection and AIDS in Bangkok, Thailand.

OBJECTIVE: To characterize the clinical spectrum of disease and immune status of adult HIV-1-infected patients in Bangkok. DESIGN: Cross-sectional survey of hospital admissions. METHODS: From November 1993 through June 1996, demographic, clinical, and laboratory data were collected from HIV-infected inpatients (> or =14 years old) at an infectious diseases hospital. RESULTS: Of 16,717 persons admitted, 3112 (18.6%) were HIV-seropositive, 2261 of whom were admitted for the first time. Of 2261, 1926 (85.2%) were male, 1942 (85.9%) had been infected heterosexually or by means not related to drug use, 319 (14.1%) were injection drug users (IDUs), and 1553 (68.7%) had AIDS. The most common AIDS-defining conditions were extrapulmonary cryptococcosis (EPC; 38.4%), tuberculosis (TB; 37.4%), and wasting syndrome (WS; 8.1%). IDUs were more likely (p < .05) to have TB or WS but less likely (p < .05) to have EPC or Pneumocystis carinii pneumonia than patients with no history of injection drug use. Lymphocyte counts were measured for 2047 (90.5%) patients; 81.8% had < or =1500 lymphocytes/microl. CONCLUSION: These HIV-infected patients were admitted with severe immunosuppression. Cryptococcosis and TB are major problems and differ in prevalence among IDUs and persons infected sexually. Clinical and immunologic information is critical in improving the lives of HIV-infected persons in Asia through prevention, treatment, and prophylaxis.

AIDS-Related Opportunistic Infections↗
PubMed1999

Short-course zidovudine for perinatal HIV-1 transmission in Bangkok, Thailand: a randomised controlled trial. Bangkok Collaborative Perinatal HIV Transmission Study Group.

BACKGROUND: Many developing countries have not implemented the AIDS Clinical Trials Group 076 zidovudine regimen for prevention of perinatal HIV-1 transmission because of its complexity and cost. We investigated the safety and efficacy of short-course oral zidovudine administered during late pregnancy and labour. METHODS: In a randomised, double-blind, placebo-controlled trial, HIV-1-infected pregnant women at two Bangkok hospitals were randomly assigned placebo or one zidovudine 300 mg tablet twice daily from 36 weeks' gestation and every 3 h from onset of labour until delivery. Mothers were given infant formula and asked not to breastfeed. The main endpoint was babies' HIV-1-infection status, tested with HIV-1-DNA PCR at birth, 2 months, and 6 months. We measured maternal plasma viral concentrations by RNA PCR. FINDINGS: Between May, 1996, and December, 1997, 397 women were randomised; 393 gave birth to 395 live-born babies. Median duration of antenatal treatment was 25 days, and median number of doses during labour was three. 99% of women took at least 90% of scheduled antenatal doses. Adverse events were similar in the study groups. Of 392 babies with at least one PCR test, 55 tested positive: 18 in the zidovudine group and 37 in the placebo group. The estimated transmission risks were 9.4% (95% CI 5.2-13.5) on zidovudine and 18.9% (13.2-24.2) on placebo (p=0.006; efficacy 50.1% [15.4-70.6]). Between enrolment and delivery, women in the zidovudine group had a mean decrease in viral load of 0.56 log. About 80% of the treatment effect was explained by lowered maternal viral concentrations at delivery. INTERPRETATION: A short course of twice-daily oral zidovudine was safe and well tolerated and, in the absence of breastfeeding, can lessen the risk for mother-to-child HIV-1 transmission by half. This regimen could prevent many HIV-1 infections during late pregnancy and labour in less-developed countries unable to implement the full 076 regimen.

Administration, Oral↗
PubMed1999

Maternal viral load and timing of mother-to-child HIV transmission, Bangkok, Thailand. Bangkok Collaborative Perinatal HIV Transmission Study Group.

OBJECTIVES: To determine the proportion of HIV-1-infected infants infected in utero and intrapartum, the relationship between transmission risk factors and time of transmission, and the population-attributable fractions for maternal viral load. DESIGN: Prospective cohort study of 218 formula-fed infants of HIV-1-infected untreated mothers with known infection outcome and a birth HIV-1-positive DNA PCR test result. METHODS: Transmission in utero was presumed to have occurred if the birth sample (within 72 h of birth) was HIV-1-positive by PCR; intrapartum transmission was presumed if the birth sample tested negative and a later sample was HIV-1-positive. Two comparisons were carried out for selected risk factors for mother-to-child transmission: infants infected in utero versus all infants with a HIV-1-negative birth PCR test result, and infants infected intrapartum versus uninfected infants. RESULTS: Of 49 infected infants with an HIV-1 birth PCR result, 12 (24.5%) [95% confidence interval (CI), 14 -38] were presumed to have been infected in utero and 37 (75.5%) were presumed to have been infected intrapartum. The estimated absolute overall transmission rate was 22.5%; this comprised 5.5% (95% CI, 3-9) in utero transmission and 18% (95% CI, 13-24) intrapartum transmission. Intrapartum transmission accounted for 75.5% of infections. High maternal HIV-1 viral load (> median) was a strong risk factor for both in utero [adjusted odds ratio (AOR) 5.8 (95% CI, 1.4-38.8] and intrapartum transmission (AOR, 4.4; 95% CI, 1.9-11.2). Low birth-weight was associated with in utero transmission, whereas low maternal natural killer cell and CD4(+) T-lymphocyte percentages were associated with intrapartum transmission. The population-attributable fraction for intrapartum transmission associated with viral load > 10 000 copies/ml was 69%. CONCLUSIONS: Our results provide further evidence that most perinatal HIV-1 transmission occurs during labor and delivery, and that risk factors may differ according to time of transmission. Interventions to reduce maternal viral load should be effective in reducing both in utero and intrapartum transmission.

Cohort Studies↗
PubMed1999

Maternal virus load and perinatal human immunodeficiency virus type 1 subtype E transmission, Thailand. Bangkok Collaborative Perinatal HIV Transmission Study Group.

To determine the rate and risk factors for human immunodeficiency virus (HIV)-1 subtype E perinatal transmission, with focus on virus load, pregnant HIV-infected women and their formula-fed infants were followed prospectively in Bangkok. Of 281 infants with known outcome, 68 were infected (transmission rate, 24.2%; 95% confidence interval, 19.3%-29.6%). Transmitting mothers had a 4.3-fold higher median plasma HIV RNA level at delivery than did nontransmitters (P<.001). No transmission occurred at <2000 copies/mL. On multivariate analysis, prematurity (adjusted odds ratio [AOR], 4.5), vaginal delivery (AOR, 2.9), low NK cell percentage (AOR, 2.4), and maternal virus load were associated with transmission. As RNA quintiles increased, the AOR for transmission increased linearly from 4.5 to 24.8. Two-thirds of transmission was attributed to virus load>10,000 copies/mL. Although risk is multifactorial, high maternal virus load at delivery strongly predicts transmission. This may have important implications for interventions designed to reduce perinatal transmission.

Acquired Immunodeficiency Syndrome↗
PubMed1999

HIV-1 and other sexually transmitted infections in a cohort of female sex workers in Chiang Rai, Thailand.

OBJECTIVES: To determine demographic and behavioural factors and sexually transmitted infections (STIs) associated with prevalent HIV-1 infection among brothel based and other female sex workers (FSWs) in Chiang Rai, northern Thailand. METHODS: Data were collected from questionnaires, physical examinations, and laboratory evaluations on Thai FSWs enrolled in a prospective cohort study in Chiang Rai, Thailand, from 1991 to the end of 1994. RESULTS: HIV-1 seroprevalence was 32% among 500 women: 47% for 280 brothel workers and 13% for 220 other FSWs (p < 0.001); 96% of infections were due to HIV-1 subtype E. At enrolment, other STIs were common: chlamydia, 20%; gonorrhoea, 15%; active syphilis (serological diagnosis), 9%; genital ulcer, 12%; seroreactivity to Haemophilus ducreyi, 21%, and herpes simplex virus type 2 (HSV-2), 76%. On multiple logistic regression analysis, HIV-1 was associated with brothel work, birth in upper northern Thailand, initiation of commercial sex at < 15 years of age, syphilis, HSV-2 seropositivity, and genital ulcer. CONCLUSIONS: Young Thai FSWs working in brothels in northern Thailand in the early phase of the HIV epidemic have been at very high risk for HIV-1 infection and several other STIs. Programmes are needed to prevent girls and young women from entering the sex industry and to reduce the risk of infection with HIV-1 and other STIs.

Adolescent↗
PubMed1998

Infection with HIV-1 subtypes B and E in injecting drug users screened for enrollment into a prospective cohort in Bangkok, Thailand.

From May through August 1995, a cross-sectional survey was conducted among injecting drug users (IDUs) drawn from 15 drug treatment clinics in Bangkok and who were not known to be HIV-seropositive, to determine the prevalence of HIV-1 subtypes B and E and related risk behaviors, and to offer enrollment in a prospective cohort study. IDUs who voluntarily consented were interviewed, and blood specimens were tested for the presence of HIV antibodies. HIV-1-seropositive specimens were tested for subtypes B' (Thai B) and E by using V3 loop peptide enzyme immunoassays specific for these HIV-1 genetic subtypes. Of 1674 IDUs studied, the mean age was 31.2 years (interquartile range, 25-37 years), 94.8% were men, and 29.3% were HIV-1-seropositive. On multiple logistic regression analysis, HIV-1 seropositivity was associated with older age, not being married, less education, needle sharing, and incarceration. HIV-1 subtype B' accounted for 65% of prevalent infections and subtype E, 35%. Infection with subtype E was associated with younger age and did not seem to be associated with sexual risk behaviors, which were uncommon in general. Bangkok IDUs continue to be at high risk for HIV-1 infection related to needle sharing and incarceration. Although HIV-1 subtype B' accounts for most prevalent infections, subtype E seems to be more prevalent among younger IDUs, and most infections seem likely to result from parenteral transmission.

Adult↗
PubMed1998

HIV-1 seroconversion in a prospective study of female sex workers in northern Thailand: continued high incidence among brothel-based women.

OBJECTIVES: To determine the incidence of HIV-1 infection, temporal trends in incidence, and risk factors for seroconversion in a cohort of female commercial sex workers (CSW) in upper northern Thailand, the region of Thailand with the highest rates of HIV-1 infection. METHODS: CSW were enrolled from 1991 through 1994 and evaluated prospectively with interviews, physical examination, testing for sexually transmitted diseases (STD), and serologic testing for HIV-1 infection. RESULTS: The incidence of HIV-1 seroconversion in the first year of follow-up was 20.3 per 100 person-years among 126 brothel-based CSW and 0.7 per 100 person-years among 159 other CSW who worked in other venues such as bars or massage parlors. Incidence remained elevated among brothel-based CSW who were enrolled later in the study compared with those who enrolled earlier. Through 1996, 30 women seroconverted. In a multivariable proportional hazards model, seroconversion was significantly associated (P < 0.05) with brothel-based sex work (adjusted risk ratio, 7.3) and Chlamydia trachomatis cervical infection (adjusted risk ratio, 3.3). CONCLUSION: Despite national HIV control efforts and declining rates of infection among young men in Thailand, brothel-based CSW may continue to be at high risk for HIV-1 infection. Additional efforts are needed to provide alternative economic choices for young women, to ensure universal condom use during commercial sex, and to develop new prevention technologies.

Adolescent↗
PubMed1998

HIV-1 subtype E incidence and sexually transmitted diseases in a cohort of military conscripts in northern Thailand.

OBJECTIVES: To determine the rate of and risk factors for HIV-1 seroconversion and describe sexually transmitted disease (STD) prevalence rates for young men in northern Thailand. METHODS: Data were collected from self-administered questionnaires and serologic testing at enrollment in a prospective study in 1991 and at follow-up after 6, 17, and 23 months on a cohort of 1115 men selected by lottery for military conscription. RESULTS: A total of 14 men seroconverted to HIV-1 envelope subtype E. The overall HIV-1 incidence rate was 1.1 (95% confidence interval [CI], 0.6-1.8) per 100 person-years (PY) of follow-up. However, the rate was 2.0/100 PY for conscripts from the upper northern subregion of Thailand compared with 0.5/100 PY from other regions (adjusted rate ratio [RR] = 2.69; 95% CI, 0.8-12.2). On multivariate analyses, the behavioral factors associated with HIV-1 seroconversion were frequency of sex with female sex workers (FSWs; p = .04), receptive anal sex (adjusted RR = 6.73; 95% CI, 1.8-21.7), and large amount of alcohol consumption (adjusted RR = 3.12; 95% CI, 1.0-10.9). Genital ulceration was the STD most strongly associated with seroconversion. The prevalence of serologic reactivity to syphilis, Haemophilus ducreyi, and herpes simplex virus type 2 increased with greater frequency of sex with FSWs and was generally higher for men from the upper north. CONCLUSION: Young men in northern Thailand are at high risk for HIV-1, primarily through sex with FSWs; and other STDs are highly associated with HIV-1 incidence. As HIV-1 infection extends into the general population, intervention programs are needed to address the problem of sexual transmission apart from commercial sex venues.

Adult↗