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Biomedical subjects

F Tan

Publications and source records attributed to F Tan.

65 records · Page 4Linked to original sources
PubMed1984

NADP-dependent glutamate dehydrogenase from a facultative methylotroph, Pseudomonas sp. strain AM1.

The NADP-dependent glutamate dehydrogenase (EC 1.4.1.4.) elaborated by the methylotrophic bacterium Pseudomonas sp. strain AM1 when growing on succinate and ammonium chloride was studied. The enzyme, which has a pH optimum of 9.0, was purified 140-fold and shown to have Km values of 20.2 mM, 0.76 mM, 0.033 mM, and 31.6 mM for ammonia, alpha-ketoglutarate, NADPH, and glutamate, respectively. The native molecular weight was determined by polyacrylamide gel electrophoresis to be 190,000, and electrophoresis under denaturing conditions in the presence of sodium dodecyl sulfate revealed a minimum molecular weight of 50,000. The enzyme was highly specific; NADH was unable to replace NADPH in the reaction, various alpha-keto acids could not replace alpha-ketoglutarate, and neither methylamine nor hydroxylamine could substitute for ammonia. Glutamate dehydrogenase was synthesized by the bacteria only when ammonia was its nitrogen source and was repressed if methylamine or nitrate were provided as sources of nitrogen instead of ammonia.

Ammonium Chloride↗
PubMed1983

Relationship between types of asthmatic reaction, nonspecific bronchial reactivity, and specific IgE antibodies in patients with red cedar asthma.

We studied the relationship between specific IgE antibodies, nonspecific bronchial reactivity to methacholine, and the type of asthmatic reaction in patients with red cedar asthma. The level of circulating specific IgE antibodies (expressed as RAST ratios) was not related to the type of asthmatic reaction, the degree of nonspecific bronchial hyperreactivity [expressed by the provocative concentration of methacholine producing a 20% decrease in the forced expiratory volume in 1 sec (PC20)] or the index of reactivity to plicatic acid. On the other hand, methacholine PC20 was found to correlate with the index of reactivity to plicatic acid in the late asthmatic reaction (LAR) and both the immediate and late components of the dual asthmatic reaction (DAR). Development of the LAR is associated with increase in nonspecific bronchial hyperreactivity. Repeated inhalation challenge with plicatic acid in eight patients with LAR resulted in DAR in all. The results suggest that the mechanism responsible for the LAR is associated with an increase in nonspecific bronchial reactivity; furthermore, the immediate component of DAR could also be related to heightened bronchial hyperreactivity.

Adult↗
PubMed1983

Epidemiologic health study of workers in an aluminum smelter in British Columbia. Effects on the respiratory system.

A health survey was carried out on all white males in an aluminum smelter in British Columbia. The survey consisted of a medical-occupational questionnaire, spirometry, chest radiography, and environmental monitoring. We have compared the results of a respiratory survey in 713 workers in the office and casting department with no significant exposure to air contaminants (control workers) with those of 797 potroom workers: 495 who spent more than 50% of their working time in the potroom (high exposure) and 302 workers who spent less than 50% of their working time in the potroom (medium exposure). Potroom workers (high) had a significantly greater prevalence of cough and wheeze than did those in the control group, and they had significantly lower mean forced expiratory volume in one second and maximal midexpiratory flow rate than did those in the control group after adjustment had been made for differences in age, height, and smoking habits. Potroom workers (medium) had a slightly greater prevalence of respiratory symptoms and lower lung function than did workers in the control group, but the differences were not significant. We were unable to demonstrate potroom asthma. The levels of total fluoride, gaseous fluoride, particulate fluoride, sulphur dioxide, and total particulates found in the potroom at the time of the study were below the currently accepted threshold limit values, but the levels of benzo-alpha-pyrene were high.

Adult↗
PubMed1982

Lack of relationship between ABH secretor status and lung function in pulp mill workers.

To evaluate whether persons who do not secrete blood group antigens in their saliva (ABH nonsecretors) are more prone to develop respiratory symptoms or lung function abnormalities than are ABH secretors, we determined ABH secretor status of 1,422 pulp mill workers who took part in an occupational health survey. There were 331 nonsecretors (23.3% of total population), and the remainder were secretors. Respiratory symptoms were not significantly different in nonsecretors when compared with secretors. Spirometric results for forced expiratory volume in one second (FEV1), maximal mid-expiratory flow (MMEF), forced vital capacity (FVC), and FEV1/FVC% were not significantly different in nonsecretors when compared with secretors, irrespective of smoking status or occupational exposure. Likewise, there was no significant difference in prevalence rates of abnormal FEV1, MMEF, or FEV1/FVC%, in nonsecretors when compared with secretors. It is concluded that ABH secretor status is not related to respiratory symptoms or spirometric abnormalities in pulp mill workers. This study suggests that ABH nonsecretor status is not a significant risk factor for the development of chronic obstructive pulmonary disease.

ABO Blood-Group System↗
PubMed1982

Complete amino acid sequence of mung bean trypsin inhibitor.

The mung bean trypsin inhibitor has been found to be microheterogeneous at N-terminal region due to the presence of several isomers. After treatment with aminopeptidase M it becomes homogeneous and is suitable for sequence determination. Based on the determination of the structures of two active fragments the complete amino acid sequence of mung bean trypsin inhibitor has been elucidated. It consists of 72 amino acid residues with 7 pairs of disulfide bonds. The results show that this inhibitor belongs to the Bowman-Birk inhibitor family.

Amino Acid Sequence↗
PubMed1981

The effects of age, smoking, and alcohol on routine laboratory tests.

The effects of age, smoking, and alcohol intake on the results of some routine hematology and clinical chemistry tests have been determined for a group of 1,826 healthy male workers. Increasing age was significantly associated with higher hemoglobin, hematocrit, SGOT, BUN, and creatinine levels and with lower total protein concentration, but there was no significant association with leukocyte count, total bilirubin, or alkaline phosphatase. Smoking was significantly associated with higher hemoglobin, hematocrit, leukocyte count, and alkaline phosphatase, and with lower total bilirubin, SGOT, total protein, and BUN, but there was no significant association with creatinine levels. Alcohol consumption was significantly associated with higher hematocrit, bilirubin, and SGOT and with lower BUN and creatinine, but there was no significant association with hemoglobin, leukocyte count, alkaline phosphatase, or total protein. The possible reasons for these effects, and their implications, are discussed.

Adult↗
PubMed1981

Use of maximal expiratory flow-volume curves with air and helium-oxygen in the detection of ventilatory abnormalities in population surveys.

Flow-volume curves with air and helium, and spirometry were obtained in 423 subjects during epidemiologic health surveys; subjects were divided into 4 groups: nonsmokers and smokers not exposed to air pollutants at work, and nonsmoking and smoking grain elevator workers. The data obtained from 78 healthy nonsmokers who were not exposed to any air contaminants at work and had no respiratory symptoms were used to develop "normal" prediction equations for each of the following parameters: forced expiratory volume in one second (FEV1), maximal mid-expiratory flow, maximal expiratory flow at 50% of vital capacity while breathing air (Vmax50), the increase in Vmax50 after breathing a mixture of helium and O2 (delta Vmax50), and the volume of isoflow (VisoV). The prediction equations thus obtained from normal nonsmokers agreed with those published in the literature. The coefficient of variation was higher for delta Vmax50 (40.7%) and VisoV (57.6%) than for FEV1 (17.7%) or Vmax50 (27.7%). Comparison of results in smokers and nonsmokers who were not exposed to any air contaminants at work indicated that Vmax50 was the best test for discriminating the effect of cigarette smoking, whereas delta Vmax50 and VisoV were not significantly different. The FEV1 was the best discriminator of the effects of grain dust. There was poor concordance among FEV1, Vmax50, and delta Vmax50 or VisoV. We concluded that FEV1 and Vmax50 are more useful parameters than are delta Vmax50 and VisoV for detecting ventilatory abnormalities in a smoking, working population and in grain elevator workers. The results suggest that the addition of the more time-consuming test, the helium flow-volume curve, is unlikely to contribute any further useful information among the populations surveyed.

Air Pollutants, Occupational↗
PubMedDate not supplied

Self-care and quality of life in patients with advanced heart failure: the effect of a supportive educational intervention.

OBJECTIVE: The goal of this study was to determine the effects of a supportive educational nursing intervention on self-care abilities, self-care behavior, and quality of life of patients with advanced heart failure. DESIGN: The study design was an experimental, random assignment. SETTING: The study was located at the University Hospital in Maastricht, The Netherlands. PATIENTS: The study included 179 patients (mean age 73 years, 58% men, New York Heart Association classification III and IV) admitted to a university hospital with symptoms of heart failure. OUTCOME MEASURES: Outcome measures included self-care abilities (Appraisal of Self-care Agency Scale), self-care behavior (Heart Failure Self-care Behavior Scale), 3 dimensions of quality of life (functional capabilities, symptoms, and psychosocial adjustment to illness), and overall well-being (Cantril's ladder of life). INTERVENTION: The intervention patients received systematic education and support by a nurse in the hospital and at home. Control patients received routine care. RESULTS: Self-care abilities did not change as a result of the intervention, but the self-care behavior in the intervention group was higher than the self-care behavior in the control group during follow-up. The effect of the supportive educational intervention on quality of life was limited. The 3 dimensions of quality of life improved after hospitalization in both groups, with no differences between intervention and control group as measured at each follow-up measurement. However, there was a trend indicating differences between the 2 groups in decrease in symptom frequency and symptom distress during the 9 months of follow-up. CONCLUSION: A supportive educational nursing intervention is effective in improving self-care behavior in patients with advanced (New York Heart Association class III-IV) heart failure; however, a more intensive intervention is needed to show effectiveness in improving quality of life.

Adaptation, Psychological↗
PubMedDate not supplied

Epidemiologic health study of workers in an aluminum smelter in Kitimat, B.C. II. Effects on musculoskeletal and other systems.

A health study was carried out on 2066 workers in an aluminum smelter in Kitimat, British Columbia to study the effects of exposure to fluoride and other air contaminants encountered on the potlines on the musculoskeletal system, hemopoietic tissue, liver, and renal function. Three hundred seventy-two railway repair workers from Squamish, British Columbia served as an "external" control group. Examination of the spine and sacroiliac joints and pelvic X-ray were conducted on long-term potline workers and a number of "internal" control workers in the smelter not exposed to any air contaminants. Urinary fluoride measurements and personal sampling for airborne fluoride were also carried out. Blood samples were collected for routine blood count and liver and renal function test. Definite cases of skeletal fluorosis were not found in any potroom workers. Some of the changes of early skeletal fluorosis described on pelvic X-rays, e.g., increased density, calcification of ligaments, and periosteal changes, were found in a few workers who were employed on the potlines for more than 10 yr. There was, however, poor agreement in the findings of the two radiologists who read the films. The entity "musculoskeletal fluorosis" does not exist in this smelter where the potroom workers were exposed to total fluoride levels below the currently accepted threshold limit value of 2.5 mg/m3. No ill effects on the hematopoietic tissue or liver and renal function were found.

Air Pollutants↗