Biomedical subjects

C Zhou

Publications and source records attributed to C Zhou.

244 records · Page 14Linked to original sources

PubMedDate not supplied

[Elimination of fat emulsions of various concentrations from the blood. Observational study in the intravenous administration of Lipovenös 10% and 20% in premature infants with very low birth weight].

Within the scope of an observation study 40 premature low birth weight infants requiring parenteral nutrition received either 10% or 20% lipid emulsions (Lipovenös) for 7 days. The 10% lipid emulsion differs from the 20% lipid emulsion in the higher phospholipid/triglyceride-ratio (0.06 resp. 0.12). Lipid infusion was commenced at 0.5 g triglyceride/kg/24 hours and increased steadily to 2 g triglyceride/kg/24 hours. The aim of the study was to compare the effects of the two intravenously administered lipid emulsions on serum clearance. The serum concentrations of triglyceride and cholesterol did not change significantly during the infusion with 20% Lipovenös. Significant increases in the triglyceride and cholesterol content were observed only in the serum of the patients who were given the 10% Lipovenös. The reduced lipid serum clearance is attributable to the higher content of phospholipids in the 10% lipid emulsion. With regard to the risk of high cholesterol concentrations and an abnormal LPX serum accumulation, administration of 20% lipid emulsion is preferable to 10% lipid emulsion, also during the neonatal period.

Cholesterol↗

PubMedDate not supplied

[Effect of corticosteroids on lung function and the clinical course of bronchopulmonary dysplasia in premature infants with a birth weight below 1,500 g].

11 very low birth weight infants (700-1480 g) with bronchopulmonary dysplasia were treated with dexamethasone (0.5 mg/kg/day for 3 days, 0.3 mg/kg/day for 3 days), followed by hydrocortisone (tapering from 2 mg/kg/day-0.5 mg/kg/day, total 4 days). Pulmonary function tests showed a significant improvement of lung compliance from initially 0.36 +/- 0.05 cm/ml H2O/kg to 0.54 +/- 0.16 cm/ml H2O/kg after 24 hours. Compliance remained within levels above baseline during the following 4 days. Steroid therapy was also associated with a significant reduction of FiO2 (0.45 to 0.34) and ventilator rates (48.9 to 29.3/min). Extubation was possible in all infants 11.9 (+/- 10) days after initial treatment.

Bronchopulmonary Dysplasia↗

PubMedDate not supplied

Respiratory symptoms and lung function in jute processing workers: a primary investigation.

This paper presents the results of an investigation of respiratory symptoms and lung function of 404 workers who had been exposed to jute dust in a jute mill. Measurement of total dust concentration and analysis of dust composition were also conducted. Most workers in the jute mill were exposed to jute dusts containing less than 5% silica, whereas a few workers were exposed to dusts containing approximately 10-15% silica. Male smokers and nonsmokers in the dust-exposed group had a higher prevalence of cough and chest tightness compared with those in the control group. Among dust-exposed workers, female nonsmokers had a significantly higher prevalence of cough, chronic bronchitis, chest tightness, and dyspnea than those in the control group. Lung function tests showed that dust-exposed workers had a greater incidence of abnormal lung function than did control workers, as measured by percentage of predicted forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and FEV1.0/FVC. Dust exposure was the main cause of respiratory symptoms and abnormal values of FEV1.0, but both cigarette smoking and dust exposure contributed to the abnormal values reported for FEV1.0.

Dust↗

PubMedDate not supplied

A longitudinal study of lung function in jute processing workers.

A 5-y follow-up study of pulmonary function was conducted in 1982 and in 1987 for 50 current and retired jute-processing workers who had been employed for more than 10 y in a jute mill in China. Control subjects, who had no history of dust or gas exposure, were selected from a paper-packing plant in the same city. Forced expiratory maneuvers were conducted in the same manner in both 1982 and 1987. The jute workers' pulmonary functions, i.e., forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and forced expiratory flow (FEF25-75%), were more compromised than were pulmonary functions in the controls for the same 5-y period; however, only the increased incidence of abnormal FEV1.0s in jute workers was statistically significant. Male jute workers had significantly higher annual decrements of FVC, FEV1.0, and FEF25-75% than did control workers. Regression analysis indicated that in 1987, predicted values of FEV1.0 and FEF25-75% for the jute workers were related to years of employment. Our results suggest that long-term exposure to jute dust could produce chronic loss of lung function.

Adult↗

PubMedDate not supplied

Simultaneous quantitation of cocaine and its major metabolites in human hair by gas chromatography/chemical ionization mass spectrometry.

A sensitive method for the simultaneous analysis of cocaine, benzoylecgonine (BE), and ecgonine methyl ester (EME) in human hair by gas chromatography/chemical ionization mass spectroscopy (GC/CIMS) is described. Hair samples are cut into 1-cm sections, washed with 1% sodium dodecylsulfate, rinsed with deionized water and methanol, and then digested overnight in a solution containing Tris buffer, sodium dodecylsulfate, Proteinase K, and dithiothreitol. Digested hair samples are extracted with Bond Elut Certify solid-phase extraction columns, derivatized with N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA), and analyzed by GC/CIMS using isobutane as reagent gas. This method is quantitative, does not cause degradation of cocaine, and requires as little as 5 mg of hair. Analysis is performed on a Finnigan ITS-40 ion trap mass spectrometer interfaced with a Varian 3400 gas chromatograph equipped with a Model 1075 split/splitless injector and a J&W DB-5 capillary column. Full scan spectra are used for identification of cocaine and its metabolites. Quantitation is based on peak area ratios of the MH+ ions, as follows: 304 for cocaine, 404 for BE-TBDMS, 314 for EME-TBDMS, and 340 for the internal standard, difluorococaine. This method can be used to quantitate cocaine at concentrations of 0.1 to 100 ng/mg hair. The coefficients of variation (%CV) at a drug concentration of 1 ng/mg hair are 10.3, 16.3, and 27.7% for cocaine, BE, and EME, respectively.

Cocaine↗

PubMedDate not supplied

Cocaine and metabolite concentrations in the hair of South American coca chewers.

Hair samples obtained from South American Indians who were identified as daily chewers of coca leaves were analyzed by a sensitive gas chromatography/mass spectrometry (GC/MS) method for cocaine, benzoylecognine (BE), and ecognine methyl ester (EME). The mean cocaine concentration in the hair of these five subjects was 15.2 ng/mg hair +/- 11.0 (range = 1.0-28.9 ng/mg), mean BE concentration was 2.8 +/- 1.6 ng/mg hair (range = 0.3-4.4 ng/mg hair), and mean EME concentration was 1.6 +/- 1.7 (range = 0.0-4.4 ng/mg hair). The finding that cocaine was present at approximately 5 times higher concentration than BE and approximately 12 times higher than EME is surprising in light of the much longer plasma half lives of these metabolites. Washing the hair before analysis with 1% dodecyl sulfate, methanol, and distilled water reduced the concentration of cocaine in the hair but also reduced the concentrations of the metabolites. These data suggest that factors other than the drug concentration in blood may be important in determining the amount of drug incorporated into hair.

Coca↗

PubMedDate not supplied

Incorporation of isotopically labeled cocaine and metabolites into human hair: 1. dose-response relationships.

Deuterium-labeled cocaine (cocaine-d5) was administered intravenously and/or intranasally in doses of 0.6-4.2 mg/kg to 25 human volunteers under laboratory clinical conditions. Sequential blood samples were collected for up to 3 days, and hair samples were collected for up to 10 months. Samples were analyzed by gas chromatography-mass spectrometry (GC-MS) for cocaine-d5 and its major metabolite, benzoylecgonine-d5 (BZE-d5). The parent drug, cocaine-d5, was the predominant analyte in hair, whereas BZE-d5 was the major analyte in blood, especially at later time periods. The amount of cocaine-d5 incorporated into hair ranged from 0.1 to 5 ng/mg hair, whereas the amount of BZE-d5 was approximately one-sixth of that concentration. The threshold dose for detection was estimated to be 25-35 mg of drug administered intravenously. A single dose could be detected for 2-6 months. Subjects receiving the same dose differed (from two to 12 times as much depending upon how it was measured) in the amount of cocaine-d5 incorporated into their hair. Non-Caucasians, in particular, incorporated more cocaine-d5 in hair than did Caucasians. Also, segmental analysis of the samples revealed considerable intersubject variability in the time drug first appeared in hair and the rate at which the drug moved along the hair shaft with time. These interindividual differences could not be explained by differences in plasma pharmacokinetics. Considered together, these results suggest that cocaine incorporation into hair may occur by way of multiple mechanisms--by way of sweat and sebum, for example--and at various times during the hair growth cycle. Thus, hair analysis using GC-MS appears to be a very sensitive method for detecting cocaine ingestion. However, within the range of doses used in the present study, hair does not provide a particularly accurate record of either the amount, time, or duration of drug use.

Administration, Intranasal↗

PubMedDate not supplied

Incorporation of isotopically labeled cocaine into human hair: race as a factor.

In order to evaluate race as a possible factor affecting the incorporation of drugs into human hair, 2 mg/kg deuterium-labeled cocaine (cocaine-d5) was administered intranasally to nine male non-Caucasian volunteers under controlled laboratory conditions. Sequential blood samples were collected for up to three days, and scalp hair samples were collected at 24 and 72 h after dosing and at monthly intervals for up to 12 months. The samples were then analyzed by gas chromatography-mass spectrometry for cocaine-d5 and benzoylegonine-d5 (BZE-d5). The amounts of cocaine-d5 found in the hair of these non-Caucasian subjects were compared with the amounts of cocaine-d5 found in the hair of Caucasian subjects who received the same cocaine dose under identical conditions as part of a study we reported previously. The non-Caucasians in the present study had approximately 2.7 times more cocaine-d5 in their hair than the Caucasian subjects in the earlier study. In five of the non-Caucasian subjects, cocaine-d5 could be detected in hair within 24 h after dosing. Curiously, we were unable to detect any cocaine-d5 in one of the non-Caucasian subject's hair at any time after dosing even though cocaine-d5 was in plasma at the expected levels. The results from these studies suggest there may be a racial bias in the incorporation of cocaine into human hair; however, the data are not conclusive because of the relatively small sample size.

Administration, Intranasal↗

PubMedDate not supplied

Predictors of longitudinal changes in pulmonary function among swine confinement workers.

OBJECTIVE: To determine predictors of longitudinal changes in pulmonary function in swine confinement workers. DESIGN: Longitudinal study conducted from November 1989 to June 1991 and January 1994 to May 1995. SETTING: Swine confinement workers in Saskatchewan. PARTICIPANTS: Forty-two swine confinement workers who were studied in 1989/90 and studied again in 1994/95. RESULTS: Of 98 male swine confinement workers (mean age SD 36.3 11.1 years) studied at baseline, 42 were studied again five years following. Complete information on baseline across-shift pulmonary function (preshift forced expiratory volume in 1 s [FEV1], forced vital capacity [FVC], and every 2 h FEV1 and FVC during the shift), and five-year follow-up pulmonary function (with FEV1 and FVC) were available on all 42 subjects. Mean across-shift changes (preshift measurement to last measurement of the day) at baseline were -159. 8 61.7 mL in FEV1 and -35.3 65.6 mL in FVC. Mean annual rate change between baseline and follow-up for FEV1 was -53.9 61.7 mL/year and for FVC -48.9 71.6 mL/year. After adjusting for age, height, smoking and hours spent in the barn, the baseline across-shift change in FEV1 and FVC was a significant predictor of annual rate change in FEV1 (P=0.01) and FVC (P=0.02), respectively. To determine the effects of indoor air quality on longitudinal lung function decline, indoor air environmental measurements were analysed. Complete information on respiratory health and indoor air quality was available on 34 of the 42 subjects. Assessment of indoor environment of swine barns included a summer and winter measurement for airborne dust, gases and endotoxin levels. After adjusting for age, height, smoking, ammonia and hours spent in the barn, the endotoxin level (Eu/mg)was a significant predictor of annual rate change for FEV1 but not FVC. CONCLUSIONS: These results suggest that shift change is an important predictor of longitudinal changes in lung function in swine confinement workers and that endotoxin exposures may mediate annual decline in FEV1 in these workers.

Adolescent↗

PubMedDate not supplied

Descriptive epidemiology of animal bites in Indiana, 1990-92--a rationale for intervention.

Animal bites are a reality of life throughout the world. They arise out of an imperfect relationship with domestic animals and wildlife. Most bite injuries are preventable. The principal approaches to community-wide bite prevention programs include reducing the number of domestic animals roaming in the community (animal control) and teaching people to refrain from behaviors likely to provoke bites. This article addresses the epidemiologic basis and justification for a bite prevention program targeted toward children. Animal bite data from Indiana for the years 1990, 1991, and 1992 were analyzed for trends that might suggest opportunities for preventive intervention. Bites inflicted by humans were not included in this data base. Children of all age groups were disproportionately affected, with the highest incidence in the 5-9 year age group. The dog and the cat were the most commonly reported biting animals. Wild and pet rodents were the next most frequent biting group. The bites most frequently reported from nonrodent wild animals were inflicted by raccoons. The incidence of animal bites in children peaked during the spring (April-June). Boys were bitten at a higher rate than girls, but this difference between the sexes narrows with age and was not noted in the adult population. Residents of urban counties (population greater than 100,000) had higher reported bite rates than residents of nonurban counties.

Adolescent↗