Antibacterial substances from staphylococci.
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Anti-Bacterial Agents↗
Biomedical subjects
C Hsu
Publications and source records attributed to C Hsu.
Lifetime needle sharing: a predictive analysis.
Through understanding predictors of needle sharing, it may be possible to design AIDS prevention interventions more effectively. Data were collected from a sample of 416 patients in two New York City methadone programs in 1990. Questions were asked about needle sharing and about a battery of predictors covering 11 psychosocial domains. Based on factor analysis, these were reduced to seven factors: criminal history, antisocial characteristics, social integration, severity of psychiatric problems, current drug involvement, physical health, and personality disorders. Bivariate analyses showed that criminal involvement, antisocial characteristics, social integration, and age were significantly related to needle sharing. With the seven factors, as well as age, gender, and ethnicity simultaneously examined by means of regression analysis, it was found that criminal involvement, severity of psychiatric problems, and age were all positively associated with needle sharing. Implications for treatment are discussed.
Acquired Immunodeficiency Syndrome↗
Comparison of M-mode and two-dimensional echocardiographic algorithms used to estimate left ventricular mass: the Coronary Artery Risk Development in Young Adults Study.
Left ventricular (LV) mass as measured from M-mode echocardiography has been shown to be an important predictor of subsequent cardiovascular morbidity and death. Investigators have debated the advantages of LV mass calculations derived from M-mode versus various two-dimensional (2D) echocardiographic algorithms. The purpose of this study was to compare measurements of LV mass made from M-mode and 2D echocardiographic formulas in 325 healthy young adults of the Coronary Artery Risk Development in Young Adults cohort. M-mode LV mass was calculated according to a necropsy-validated formula, whereas 2D LV mass was calculated according to two established algorithms (i.e., the biplane Simpson and truncated ellipsoid methods). LV mass derived from M-mode echocardiography was 162.7 +/- 52 gm (mean +/- SD). Mean (+/- SD) LV mass derived from 2D echocardiographic measurements were as follows: with the biplane Simpson method (four-chamber view), 164.2 +/- 42 gm; with the biplane Simpson method (two-chamber view), 159.8 +/- 44 gm; with the truncated ellipsoid method (four-chamber view), 139.8 +/- 37 gm; and with the truncated ellipsoid method (two-chamber view), 143.1 +/- 38 gm. Correlations between M-mode and 2D methods ranged from 0.75 to 0.81 (p < 0.0001 for each comparison), and correlations between 2D methods were all greater than 0.90. This study has demonstrated that measurements of LV mass calculated from M-mode and 2D formulas correlate well with each other. Nonetheless, LV mass calculated from the truncated ellipsoid formula averages approximately 20 gm less than that calculated from the 2D biplane Simpson or M-mode echocardiographic formulas. These systematic differences in calculated values for LV mass must be taken into account when choosing an LV mass algorithm for use in cross-sectional and serial studies.
Adolescent↗
Cell-surface antigens expressed on L-cells transfected with whole DNA from non-expressing and expressing cells.
We have shown previously that transfection of mouse L-cells with DNA from JM, a human T-cell line expressing certain T-cell differentiation antigens, yields stable transfectants expressing one or another of these antigens. The identities of the antigens were confirmed by immunoprecipitation and SDS-polyacrylamide gel electrophoresis. We now report that our procedure--co-transfection with the chicken thymidine kinase gene (tk) and whole cellular DNA, selection with hypoxanthine-aminopterin-thymidine (HAT), and staining of the cells with fluorochrome-conjugated monoclonal antibodies and fluorescence-activated cell-sorter (FACS) selection--yields transfectants expressing a variety of cell-surface molecules (19 of 21 investigated), most at a frequency of about one per 10(3) Tk+ transformants. Of these, 9 of 12 were transferred and expressed as readily using DNA from cells which did not express the cell-surface antigens as from tissues or cells that did express them.
Animals↗
Gene transfer and molecular cloning of the rat nerve growth factor receptor.
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Amino Acid Sequence↗
Microencapsulation reactor scale-up by dimensional analysis.
A microencapsulation process for preparing protein-loaded microspheres based on a solvent-extraction method was scaled up using continuously stirred tank reactors (CSTR) from 1 L to 100 L in batch size. This study was concerned with developing a quantitative correlation between the size of the microspheres and process parameters. The process parameters considered include operational variables and physical properties associated with both the dispersion and dispersed phases. Dimensional analysis was used to establish such a correlation based on protein-free poly(lactic acid-co-glycolic acid) microspheres in an oil-in-water emulsion system prepared in a 1 L CSTR. This correlation was found to accurately describe the preparation of protein-loaded microspheres in a solid-in-oil-in-water system. Poly(methyl methacrylate) was found to behave similarly to poly(lactic-acid-co-glycolic acid) and could be used as a model polymer for scale-up investigation. This study showed that dimensional analysis can be used to predictably scale the current microencapsulation process up to 100 L to produce particles of defined size.
Carboxymethylcellulose Sodium↗
Liquid-liquid emulsification by static mixers for use in microencapsulation.
4e report a feasibility study on liquid-liquid emulsification by static mixers for use in microencapsulation. This study was concerned with developing a quantitative correlation between the size of the microspheres and process parameters. The process parameters considered included operational variables and physical properties associated with both the dispersion and dispersed phases. The effect of mixing element design on mixing efficiency and particle-size distribution was evaluated using three different static mixers. The performance of static mixers and conventional continuously stirred-tank reactors was assessed in several different aspects. Dimensional analysis was used to establish a correlation based on protein-free poly(lactic acid-co-glycolid acid) and poly(methyl methacrylate) microspheres in an oil-in-water emulsion using 1/4", 1/2" and 1" static mixers. This correlation accurately described the preparation of protein-loaded microspheres and provided large-scale microsphere production with a empirical basis.
Biocompatible Materials↗
Enhancement of methacholine-stimulated guanosine 3':5'-cyclic monophosphate formation in supersensitive guinea pig vasa deferentia.
Decentralization of the guinea pig vas deferens resulted in supersensitivity of the contractile response to methacholine. Methacholine also elevated cyclic GMP to a greater extent in the decentralized vas deferens than in sham-operated controls. Decentralization did not alter basal cyclic AMP or cyclic GMP content. These observations are analogous to the enhanced responsiveness of cyclic AMP formation in supersensitive beta adrenergic systems.
Animals↗
Diagnostic pitfalls in the fine needle aspiration of thyroid nodules. A study of 555 cases in Chinese patients.
The diagnostic value and limitations of fine needle aspiration (FNA) were determined by examining 555 palpable thyroid nodules in Chinese patients who had a definitive diagnosis established by thyroidectomy (529 cases) or large-needle biopsy (26 cases). Of the aspirates, 97.8% were satisfactory for cytologic examination. The overall malignancy rate was 20%. FNA detected 73 (74.5%) of 98 primary malignant tumors and 9 (90%) of 10 metastatic tumors. Diagnostic errors were most commonly due to inadequate specimens and cystic lesions. Cystic fluid, present in one-third of all lesions, was associated with a malignant nodule in 13% of the cases. FNA was most valuable for detecting papillary carcinomas; it may at times suggest the likelihood of a follicular carcinoma.
Adenoma↗
[An epidemiological study of 6 year-old children not attending school. I. Preliminary findings from Taipei City].
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Child↗
Cytologic diagnosis of lung tumors from bronchial brushings of Chinese patients in Hong Kong.
In 1,156 single or multiple specimens obtained from fiberoptic bronchoscopy on 1,016 Chinese patients in Hong Kong, a positive diagnosis of malignancy was made on cytologic examination in 288 and a histologic type assigned. On histologic examination of tissue, malignant tumors were diagnosed in 284 cases. The total positive yield by cytology was 88%, and the overall cytologic accuracy in correlation with histology was 73%. Comparing cases typed by cytology and by histology, the diagnostic accuracy of cytology was 83% in squamous-cell carcinoma, 81% in small-cell carcinoma, 69% in adenocarcinoma and 46% in large-cell carcinoma. The detection rate of nonbronchogenic tumors was 50%. Bronchogenic tumors showed a low male:female ratio, 1.96:1, whereas 80% of squamous-cell carcinomas and 45% of adenocarcinomas occurred in males. All seven cases of bronchogenic carcinoma in patients under 40 years of age occurred in males.
Adenocarcinoma↗
Exfoliative cytology in the evaluation of interferon treatment of cervical intraepithelial neoplasia.
Local interferon injection in four patients with cervical intraepithelial neoplasia (CIN) regularly elicited progressive regression of the lesions. The response was observed with exfoliative cytology after each injection, guided by colposcopic examination. The cytologic changes showed a cytocidal effect mainly on the dyskaryotic cells, preceded by cellular degeneration not unlike that of nonspecific inflammation and accompanied by an increase in neutrophil infiltration. The cytologic response was closely correlated with partial or complete clinical regression based on the absence of viable or degenerated dyskaryotic cells in the cervical smears. Three patients showed complete clinical regression after treatment. One patient showed recurrent viable dyskaryotic cells when the dosage was reduced, and treatment was suspended temporarily although her lesion had regressed completely after five injections. Clinical recurrence was noted one week after viable dyskaryotic cells reappeared in her smears. These observations suggest that cytology may be a useful means of monitoring interferon treatment in CIN.
Adult↗
Dietary habits of first-year medical students assessed during clinical nutrition course.
To enhance the Introduction to Clinical Nutrition course at the University of Alabama at Birmingham, medical students taking the course from 1989 to 1992 (n = 616) were required to analyze by computer the nutrient composition of their own diets for a 24-h period. In 1991 and 1992, they were required to repeat the analysis at the completion of the course. Overall, fat comprised 30% of energy intake, and along with saturated fat and the cholesterol-saturated fat index, it declined virtually each year compared with the previous year. Significant changes were noted by the end of the course in 1991 and 1992 compared with the beginning, when fat comprised 26% of energy, and more students adhered to recommendations for dietary fat, saturated fat, and fiber. Vitamin C intakes exceeded the recommended dietary allowance by more than twofold and increased further by the end of the course in 1991 and 1992, probably indicating an increase in fruit and vegetable intake. Each year, most students rated the dietary assessment as moderately or very useful. These data suggest that dietary self-assessment is a useful tool for teaching clinical nutrition in medical schools and that, even before instruction in clinical nutrition, medical students are favorably altering their dietary patterns to a greater extent than the general population.
Adult↗
The statistical analysis of cancer inhibition/promotion experiments.
The purpose of this paper is to address the very important problem of accurate statistical analysis of certain types of cancer inhibition/promotion (IP) experiments. These experiments are routinely used by the National Cancer Institute to test the effects of potential chemopreventative agents. The statistical analysis is difficult since there is Type I censoring. In the IP experiments under investigation, laboratory animals (rats) are injected with a single dose of either a direct or indirect acting carcinogen. In the mammary tumor system, animals in the control group generally develop 5-7 tumors and typical experiments are usually terminated after 4-6 months. Animals are sacrificed at the end of the experiment and all observed tumors are confirmed. The two most common response variables are the number of observed tumors per animal and the rate of tumor development. The difficulty in analyzing these experiments occurs because experiments are terminated before all induced tumors have been observed. Fewer observed tumors in one group compared to another could be the result of a decreased number of induced tumors, a decrease in growth rate, or a combination of both. It is essential for the experimenter to distinguish between these two different biological actions. Present statistical techniques do not account for this confounding and since they rely primarily on nonparametric procedures, do not present an accurate description of potential IP agents. In this paper we introduce a parametric procedure that explicitly acknowledges the confounding present in experiments of this nature. The analysis is based on the comparison of the mean number of tumors per group (lambda) and the mean time to tumor appearance (mu). A longer mean time to development is believed to indicate a slower tumor growth rate. Hypothesis tests are developed to determine if there is an overall experiment effect, to isolate which groups are contributing to an observed experiment effect, and to isolate factors (tumor number and/or growth rate) contributing to an observed group difference. Confidence regions for (lambda, mu) are also generated. This analysis leads to a better understanding of how potential IP agents function.
9,10-Dimethyl-1,2-benzanthracene↗
Cisplatin, etoposide, and weekly high-dose 5-fluorouracil and leucovorin infusion (PE-HDFL)--a very effective regimen with good patients' compliance for advanced gastric cancer.
We have previously shown that weekly 24-hour infusion of high-dose 5-fluorouracil and leucovorin (HDFL), a regimen initially designed for the treatment of advanced colorectal cancer, is also effective in the treatment of gastric cancer. This HDFL regimen is unique in that it is virtually non-myelosuppressive, and thus provides a comerstone on which ideal protocols may be developed. In this prospective phase II study, we examined the efficacy and toxicity of PE (cisplatin, etoposide)-HDFL, a HDFL-based combination chemotherapy, in the treatment of advanced-gastric cancer. This regimen consisted of cisplatin 60 mg/m2, i.v., D1; etoposide 65 mg/m2, i.v., D1-3; and 5-fluorouracil 2600 mg/m2 plus leucovorin 300 mg/m2, 24-hour i.v. infusion by an ambulatory infusion pump, D2,9,16; repeated every 4 weeks. The major eligibility criteria of the patients included: a) a histologically confirmed, objectively measurable, recurrent or primary inoperable gastric adenocarcinoma; b) age > or = 75 years; c) a Karnofsky performance status > or = 50%; d) an absolute granulocyte count (AGC) > or = 2000/mm3, and a platelet count > or = 100,000/mm3; e) a serum bilirubin concentration < or = 2.0 mg/dl; f) a serum creatinine concentration < or = 1.5 mg/dl; and g) a signed informed consent. Between March 1992 and June 1996, a total of 42 patients were enrolled onto the study. There were 31 men and 11 women with a median age of 54 (24-75) years; these included 16 primary metastatic, 3 locally advanced and inoperable, and 23 postgastrectomy recurrent gastric cancer patients. ECOG (Eastern Cooperative Oncology Group) grade III/IV leukopenia and thrombocytopenia developed in 34.0% and 11.0% of a total of 229 courses given, respectively. There was no treatment-related death. Four patients developed a reversible neurotoxicity; and two of them refused further chemotherapy. Among the 40 patients evaluable for responses, 9 [22.5%; 12-38%, 95% confidence interval (C.I.)] patients achieved complete remission, and 20 [50.0%; 33-67%, 95% C.I.] patients achieved partial remission. The overall response rate was 72.5% [56-86%, 95% C.I.]. The overall median survival and median time to progression of the responders were 10 and 7 months, respectively. The overall median survival of the whole group was 9 months. We concluded that PE-HDFL is a highly effective treatment for advanced gastric cancer. The treatment-related toxicity was mild and the patients' compliance was satisfactory.
Adenocarcinoma↗