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Biomedical subjects

A Chao

Publications and source records attributed to A Chao.

At least 55 records · Page 3Linked to original sources
PubMed1997

Seasonal variation in suicides re-examined: no sex difference in Hong Kong and Taiwan.

The seasonal variation in suicides in Hong Kong and Taiwan during the period 1981 to 1993 was examined using harmonic analysis. A single cycle per year with lowest incidence in the winter months was found in both locations and for both sexes. Despite the regional differences in ascertainment procedures and preferred suicide methods, the absence of a biseasonal distribution of female suicides was consistently observed. This finding was contrary to that reported in many Western countries. A non-shared psychosocial process underlying the cross-cultural differences in the seasonality of female suicide is suggested.

Cross-Cultural Comparison↗
PubMed1997

Comparison of neuromuscular action of rocuronium, a new steroidal non-depolarizing agent, with vecuronium.

BACKGROUND: Rocuronium is a new nondepolarizing muscle relaxant. It features a rapid onset and lack of histamine release: It has an intermediate onset of action as vecuronium. The purpose of this study was to compare the neuromuscular action and condition of intubation after a bolus dose of rocuronium or vecuronium (2 x ED90). We also compared the duration of relaxation after intubation and maintenance doses of each drug. METHODS: Sixty male or female patients, age 18-65, scheduled for elective surgery under general anesthesia were divided randomly into two groups (rocuronium and vecuronium group). All patients were ASA class I-II and pre-operative laboratory data were normal. Anesthesia was performed with fentanyl, isoflurane and O2. Rocuronium 0.6 mg/kg (2 x ED90) or vecuronium 0.1 mg/kg (2 x ED90) was given during induction of anesthesia. The response of adductor pollicis was measured with acceleromyography. Neuromuscular block was maintained by bolus injection of rocuronium 0.15 mg/kg or vecuronium 0.025 mg/kg when T1 reached 25% of control. Onset time, duration, recovery indices, intubation condition and T4/T1 ratio to 70% were recorded. Side effects were recorded during the study. RESULTS: The onset time was significantly longer in vecuronium group than that of rocuronium group (102.8 +/- 26.9 s vs. 54.9 +/- 10.9 s, p < 0.05). The clinical durations of action were respectively 44.2 +/- 13.2 min in rocuronium group and 42.5 +/- 9.1 min in vecuronium group (T1 to 25%). The duration of the maintenance were respectively 28.8 +/- 9.5 min in rocuronium group and 26.1 +/- 6.8 min in vecuronium group (T1 to 25%). No adverse effect occurred with either drug. The intubation condition was similar in both groups. CONCLUSIONS: We conclude that rocuronium provides a more rapid onset of action than that of vecuronium. Rocuronium is an intermediate-acting muscle relaxant as vecuronium with good to excellent intubation condition. It may be an useful alternative to vecuronium for rapid tracheal intubation.

Adolescent↗
PubMed1997

Prediction of bleeding diathesis in patients undergoing cardiopulmonary bypass during cardiac surgery: viscoelastic measures versus routine coagulation test.

BACKGROUND: Severe hemorrhagic tendency often complicates cardiopulmonary bypass (CPB) in cardiac surgery. In this study, we compared the effectiveness of thromboelastography (TEG), Sonoclot (SCT), and routine coagulation test (RCT) in the prediction of coagulation defects. METHODS: Forty-three patients undergoing cardiac surgery with CPB were included. Blood for RCT, TEG, and SCT profiles was sampled before systemic heparinization and after protamine administration. Clinically significant bleeding was defined as chest tube drainage in excess of 100 ml/h for 3 consecutive hours or 300 ml/h in 1 h. All coagulation parameters obtained before and after CPB were compared. The sensitivity, specificity, accuracy, false positive, and false negative rate were also calculated and compared. RESULTS: All coagulation tests were within normal range except higher partial thromboplastin time. Variables which were significantly different from those before CPB included platelet count, fibrinogen level, prothrombin time, and thrombin time in RCT, alpha angle and maximum amplitude in TEG, and R2 and peak time in SCT. In the TEG tracing, all variables had high sensitivity, specificity, and accuracy (average 85.4%, 83%, and 83.5% respectively) and low false positive and negative rate (12.5% and 5% respectively). Although SCT had high sensitivity (76.3%) and low false negative rate (6.5%), its specificity and accuracy were all under 50%. CONCLUSIONS: Our data demonstrated that the TEG monitoring is a useful tool for detecting post-CPB bleeding diathesis and can provide much predictive information. RCT and SCT are of limited value because of higher rate of unreliable results.

Blood Coagulation Tests↗
PubMed1996

Decreasing rates of cervical cancer among American Indians and Hispanics in New Mexico (United States).

Minority women in New Mexico (United States)--including American Indian and Hispanic women--have shown disproportionately high incidence rates of invasive cervical cancer during the 1960s and 1970s. Several public health programs in New Mexico were directed toward early detection of cervical cellular abnormalities, particularly targeting the state's minority women. To evaluate the effectiveness of these programs, we examined the New Mexico Surveillance, Epidemiology, and End Results (SEER) data collected from 1969-92, and calculated average annual, age-specific, and age-adjusted incidence rates by ethnic group (American Indian, Hispanic, and non-Hispanic White) for five-year time intervals. We also calculated age-adjusted mortality rates for cervical cancer in the same ethnic groups using state vital records. Age-adjusted incidence rates for invasive cervical cancer show substantial temporal decreases, especially for minority women in the state. The age-adjusted incidence rate decreased by 66 percent, from 30.3 to 10.3 per 100,000 for American Indian women, and by 61 percent, from 26.1 to 10.2 per 100,000 for Hispanic women. A stage shift to earlier stages of cervical neoplasia occurred over the study period, with a substantially higher proportion of in situ compared with invasive cancers diagnosed in the most recent cf the most remote time period. The ratio of incidence rates of in situ to invasive cancers changed dramatically for both American Indian and Hispanic women. Cervical cancer mortality rates decreased steadily among Hispanic women from 1958 to 1992; the decrease among American Indian women was less stable and fluctuated due to small numbers. Ongoing targeted screening programs should help to reduce cervical cancer incidence and mortality further in New Mexico.

Adult↗
PubMed1996

Vitamin A deficiency and T-cell subpopulations in children with meningococcal disease.

Although group A meningococcal disease is a major cause of child morbidity and mortality in sub-Saharan Africa, little is known about vitamin A status and T-cell subpopulations in affected children. A prospective study of vitamin A levels and T-cell subpopulations was conducted in 41 children hospitalized for meningococcal meningitis in Butare, Rwanda, during an epidemic from September through November, 1992. The mean age of cases was 3.6 +/- 2.7 years (range 0.5-16 years). The case-fatality rate was 20 per cent; 73 per cent of the children had serum vitamin A levels consistent with subclinical deficiency (< 0.7 mumol/l), and 27 per cent had levels consistent with severe deficiency (< 0.35 mumol/l). Mean CD4 per cent was higher and CD8 per cent was lower among children with meningitis compared with known reference populations. These results suggest that meningococcal disease is characterized by T-cell subpopulation alterations and vitamin A deficiency.

Adolescent↗
PubMed1995

Diagnostic utility of immune-complex-dissociated p24 antigen detection in perinatally acquired HIV-1 infection in Rwanda.

We evaluated the diagnostic utility and prognostic value of immune-complex-dissociated (ICD) HIV-1 p24 antigen detection in a prospective cohort study of perinatally acquired HIV-1 infection in Butare, Rwanda. HIV-1 p24 antigen was measured after acid dissociation in plasma samples collected at 6 weeks and 3 months of age from 36 HIV-1 infected and 80 uninfected children born to HIV-1 infected women. Among children with persistent HIV-1 antibody after 12 months of age, 26.7% of samples tested ICD HIV-1 p24 antigen positive. Among children who died between 3 and 12 months of age but were classified as HIV-1 infected, 17.6% tested p24 antigen positive at 6 weeks of age and 33.3% at 3 months of age. Female infants were more likely to test p24 antigen positive than male infants (p = 0.046). The specificity of the assay was 96.8%. Cumulative probabilities of child survival to 36 months of age were computed by HIV-1 status of the child and early p24 antigenemia. The mean survival time was 7 months for HIV-1 infected children with a high (> 50 pg/ml) p24 antigen concentration versus 20 months for children with p24 antigen concentrations between 10 and 50 pg/ml (p = 0.02). Cumulative probabilities of survival to 36 months of age were 0% among HIV-1 infected children with at least one positive p24 antigen test, 44% among confirmed HIV-1 infected children who were p24 antigen-negative at both 6 weeks and 3 months of age, and 95% among seroreverting children (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS Serodiagnosis↗
PubMed1995

The Zavanelli maneuver for relief of abdominal dystocia associated with gastroschisis.

A patient with acute hydramnios and advanced preterm labor at 34 weeks was seen after gastroschisis had been diagnosed by second-trimester fetal ultrasonography. The fetus also had meconium peritonitis and acute ascites. The distended abdomen did not decompress spontaneously during the second stage of labor. Severe abdominal dystocia was resolved with the Zavanelli maneuver (cephalic replacement) and cesarean delivery. This is the first reported use of the Zavanelli maneuver for abdominal dystocia.

Abdominal Muscles↗
PubMed1994

Risk factors associated with prevalent HIV-1 infection among pregnant women in Rwanda. National University of Rwanda-Johns Hopkins University AIDS Research Team.

This study evaluated risk factors associated with prevalent HIV-1 infection among pregnant women in a semi-rural but densely populated area surrounding the town of Butare in Rwanda. Overall seroprevalence was 9.3% in 5690 pregnant women who sought antenatal care at one of five health centres. Factors associated with higher seroprevalence of HIV-1 included history of multiple sexual partners, history of at least one sexually transmitted disease (STD), relatively high socioeconomic status (SES), being unmarried, young age at first pregnancy, and low gravidity. Women who had used oral contraceptives, smoked more than one cigarette per day, whose partners were circumcised, and had had sex to support themselves were also at higher risk of being infected. A history of blood transfusion in the past 5 years was not associated with HIV-1 infection. History of multiple sexual partners, history of STD, high household income, partner circumcision, and past oral contraceptive use remained strongly associated with HIV-1 infection even when simultaneously controlling for other covariates. Among legally married women who lacked sexual behaviour risk factors, history of STD, high SES, young age at first pregnancy, and low gravidity were significantly associated with HIV-1 seroprevalence.

Adolescent↗
PubMed1994

A survey of occupational blood contact and HIV infection among traditional birth attendants in Rwanda.

OBJECTIVE: To investigate the risk of occupationally acquired HIV infection among traditional birth attendants (TBA) in Rwanda, Africa. DESIGN AND METHODS: A serosurvey was conducted among 219 TBA practicing in a rural but densely populated area in southern Rwanda. Each TBA was interviewed about sociodemographic information, work-related habits and practices, and presence of nonoccupational risk factors for HIV infection. The frequency of skin exposure to HIV-infected blood was estimated for each TBA from HIV seroprevalence data collected previously from pregnant women stratified by the geographic zones in which the TBA practiced. RESULTS: Four TBA (1.8%) tested HIV-1-antibody-positive; all four had reported nonoccupational risk factors for HIV infection. We estimated that the 215 HIV-negative TBA had 2234 potentially infectious blood-skin contacts out of a total of approximately 35,000 deliveries assisted in the past 5 years. However, we found no evidence of HIV infection caused by occupational blood contact (none out of 2234; upper limit of the 95% confidence interval because of one potentially infectious blood-skin contact = 0.2%). CONCLUSION: Although these findings may not be universal to all TBA in Africa, the risk of occupationally acquired HIV infection among TBA appears small. The high frequency of blood-skin contact among TBA in Rwanda highlights the need to include infection control precautions in the training of TBA.

Adult↗
PubMed1994

Incident HIV-1 infection in a cohort of young women in Butare, Rwanda.

OBJECTIVE: To determine the incidence of HIV-1 infection and associated risk factors among young, seronegative, and sexually active women in a mixed rural and urban population in southern Rwanda. DESIGN: A prospective cohort study. METHODS: Between October 1991 and April 1993, we completed a 2-year follow-up survey among HIV-1-seronegative women aged < or = 30 years at the time of their initial HIV-1 screening during pregnancy. All women aged < or = 25 years and a randomly selected sample of 26-30-year olds were invited to participate from five prenatal clinics in the Butare region. The interview focused on potential risk factors for HIV-1 acquisition during the 2-year interval between blood collection. RESULTS: Out of 1524 women selected, 1150 (75%) participated in the follow-up survey. The 2-year incidence of HIV-1 infection was 2.7% [95% confidence interval (CI), 1.8-3.9]. Teenage women were at the highest risk (incidence, 10.5%; 95% CI, 5.2-19.4), with incidence leveling off with increasing age (P < 0.001). Women who began sexual activity recently were also at higher risk; the lowest risk category consisted of women aged 26-30 years with 5 or more years of sexual experience. The more urban the geographic residence of the woman, the more likely she was to have acquired HIV-1 infection (P < 0.001). In the urban and peri-urban zones, the poorest women were at significantly higher risk of incident HIV-1 infection than women reporting higher household income. In a multivariate analysis, young maternal age, marital status (being single, divorced or widowed), multiple sexual partners, and a history of sexually transmitted diseases remained strongly associated with incident HIV-1 infection. Geographic residence, hormonal contraception, and receipt of injections were no longer significantly associated with incident HIV-1 infection when these other factors were accounted for simultaneously. CONCLUSION: Among young Rwandan women, the early years of sexual activity are particularly dangerous for acquisition of HIV-1 infection. Interventions should focus on young teenagers before they become sexually active.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Maternal human immunodeficiency virus 1 infection and intrauterine growth: a prospective cohort study in Butare, Rwanda.

A prospective cohort study of 318 human immunodeficiency virus 1 (HIV-1)-infected and 309 seronegative pregnant women was carried out in Butare, Rwanda. Birth weight was significantly lower among singleton infants born alive to HIV-1-infected mothers compared with those born alive to seronegative mothers (2706 g vs. 2825 g; P = 0.002). Crown-to-heel length, head circumference, chest circumference and placental weight were also reduced. Maternal HIV-1 infection was significantly associated with intrauterine growth retardation but not with preterm birth. Differences in the body mass index and weight/head ratio suggest that the adverse impact on live born infants may have been most severe towards the end of pregnancy, resulting in a lean infant with a relatively large head. The higher frequency of intrauterine growth retardation could not be explained by potential confounding factors such as maternal cigarette smoking, history of sexually transmitted diseases or sociodemographic characteristics. The neonatal physical examination did not reveal any differences in clinical signs or symptoms within 48 hours of birth except for the presence of conjunctivitis which was more common among infants of HIV-1-infected mothers. The perinatal and neonatal mortality rates were not significantly affected by maternal HIV-1 status.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Growth discordancy, birth weight, and neonatal adverse events in third trimester twin gestations.

In order to understand the effects of intrauterine growth discordancy (15% or more birth weight difference), birth weight, and gestational age on the neonatal adverse events (including 1- or 5-min Apgar scores < 7, neonatal death, ICU admission, respiratory distress, hypoglycemia, hypocalcemia, perinatal infection, blood transfusion, and hyperbilirubinemia) in third trimester twin gestations, 279 consecutive twin pairs delivered from January 1986 to December 1991 were studied. Univariate analyses showed discordant twins were smaller than concordant twins in gestational age by 1.4 weeks (35.74 and 37.14 weeks respectively). When birth weight was compared, that of smaller (one with lower birth weight in a pair) discordant twins (1,951 g) was significantly lower than that of smaller concordant twins (2,423 g), while larger (one with higher birth weight in a pair) discordant twins (2,556 g) and concordant twins (2,594 g) showed no significant difference. Univariate analysis indicated there was a tendency for adverse events to occur in discordant twins, especially in the smaller twin. Through logistic regression analysis, it was found that birth weight and gestational age, but not discordancy, are the predictors of the occurrence of adverse events. A smaller twin weighing no more than 2,000 g has a 10 times greater risk to develop an adverse event as compared to a twin with a birth weight over 2,000 g and a similar gestational age; while a twin with a gestational age of less than 34 weeks has a 5 times greater risk than one 34 weeks or over with a similar birth weight.

Apgar Score↗
PubMed1994

Difference in efficacy of the Cell Saver in coronary bypass grafting surgery and cardiac valvular reoperations.

The efficacy of the Cell Saver in reducing transfusion requirements in patients who underwent either coronary artery bypass grafting (CABG) or reoperation for valvular replacement (Redo) were prospectively studied in 112 patients. In 41 patients, the Cell Saver was used from the beginning of the surgery (group 1), and in the other patients, no blood conservation techniques were undertaken (group 2). Perioperative hematological profile, postoperative chest tube drainage and transfusion requirements were examined in all patients. More red cells could be retrieved from the Redo patients than from the CABG patients (p < 0.05) during operation. The use of the Cell Saver in CABG patients reduced the total amount of blood transfusion required (p < 0.001). However, in the Redo patients, the use of the Cell Saver did not reduce the transfusion requirements during hospitalization. Furthermore, the amount of platelet concentrates transfused in the group 1 Redo patients was greater than the group 2 Redo patients. The use of the Cell Saver did not increase the postoperative chest tube drainage in either the CABG or the Redo patients. We conclude that the Cell Saver is useful in CABG patients, as far as the reduction of transfusion requirements is concerned; however, its efficacy in reducing transfusion requirements for Redo patients is questionable.

Blood Transfusion, Autologous↗
PubMed1994

Hyperbilirubinemia after cardiac operation. Incidence, risk factors, and clinical significance.

Three hundred and two consecutive patients who had undergone cardiac operation for various cardiac lesions were studied prospectively to evaluate the incidence, risk factors, and the associated mortality of postoperative hyperbilirubinemia after cardiopulmonary bypass. Concentrations of the serum total (conjugated and unconjugated) bilirubin, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase, albumin, globulin, and serum haptoglobin were measured before the operation and again on the first, second, and seventh postoperative days. Postoperative hyperbilirubinemia was defined as occurrence of a serum total bilirubin concentration of more than 3 mg/dl in any measurement during the postoperative period. Logistic regression was done to identify possible risk factors for postoperative hyperbilirubinemia. Overall incidence of postoperative hyperbilirubinemia was 35.1%; the incidence of postoperative hyperbilirubinemia was higher in patients whose valves were replaced with mechanical prostheses than in those without prostheses (p < 0.00001). In patients with postoperative hyperbilirubinemia, 70% of the increase of total bilirubin on the first postoperative day came about from an increase in unconjugated bilirubin. Serum haptoglobin decreased significantly at the same time (p < 0.01). Development of the postoperative hyperbilirubinemia was associated with a higher mortality (5.6% versus 0.5%, p < 0.01) and higher frequency of use of intraaortic balloon counterpulsation, especially for patients in whom the highest postoperative total bilirubin occurred after the first 2 days. The numbers of valves replaced, preoperative right atrial pressure, and preoperative total bilirubin concentration are the significant risk factors that, in combination, correctly predict the occurrence of postoperative hyperbilirubinemia in 80% of the patients. We concluded that postoperative hyperbilirubinemia results mainly from an increase in unconjugated bilirubin and is associated with higher mortality, especially for patients in whom highest postoperative total bilirubin occurred late after operation. Patients with the higher preoperative right atrial pressure and total bilirubin level who then underwent multiple valve replacement procedures are at greater risk for development of postoperative hyperbilirubinemia.

Cardiac Surgical Procedures↗
PubMed1993

Accuracy of recall of hip fracture, heart attack, and cancer: a comparison of postal survey data and medical records.

Accuracy of recall of hip fracture, heart attack, and cancer was evaluated by comparing data obtained from postal surveys and medical records of participants in the Leisure World Disease Prevention Study. The study cohort comprised 13,897 residents of Leisure World Laguna Hills who responded to a questionnaire first mailed in 1981. Follow-up questionnaires requesting information on recent disease history were mailed in 1983 and 1985 to all living cohort members and were returned by 9,734 (86%) and 8,884 (82%) persons, respectively. The proportion of false-positive answers was about 40% for acute myocardial infarction, but less than 10% for hip fracture and cancer. Many of those who gave a false-positive answer on the questionnaire had a condition that the lay population might easily confuse with the condition of interest (e.g., heart attack vs. other cardiovascular disease). Among persons with the disease of interest recorded in the medical record, the percentage who failed to report their events on the questionnaires was highest for those who had an acute myocardial infarction, followed by those who had cancer and those who had hip fracture. The highest rates of confirmation of cancer were for cancers of the breast, bladder, prostate, and uterus. For closely related sites (e.g., colon and rectum), the reliability of reports decreased. The amount of information obtained varied according to the wording of the questionnaire and the specificity of the questions asked. Improved accuracy of recall was observed when the occurrence of specific diseases was asked in addition to a general question about recent hospitalizations.

California↗