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Biomedical subjects

S Wong

Publications and source records attributed to S Wong.

At least 253 records · Page 14Linked to original sources
PubMed1984

Papain hydrolysis of X-phenyl-N-methanesulfonyl glycinates: a quantitative structure-activity relationship and molecular graphics analysis.

The hydrolysis of 32 X-phenyl-N-methanesulfonyl glycinates by papain was investigated. It was found that the variation in the Michaelis constants could be rationalized by the following correlation equation: log 1/Km = 0.61 pi '3 + 0.46 MR4 + 0.55 sigma + 2.00 with a correlation coefficient of 0.945. In this expression, pi '3 is the hydrophobic constant for the more lipophilic of the two possible meta substituents, MR4 is the molar refractivity of 4-substituents, and sigma is the Hammett constant summed for all substituents. Using this equation, we designed, synthesized, and successfully predicted Km for a new congener intended to maximize binding (1/Km). The interactions involved in enzyme-substrate binding, as characterized by the correlation equation, are interpreted using a computer-constructed color three-dimensional-graphics molecular model of the enzyme active site. The nonenzymatic hydrolysis (both acid and basic) of phenyl hippurates yield rate constants which are well correlated by Hammett equations; however, log k for both acid and alkaline hydrolysis are not linearly related to log 1/Km or log kcat/Km.

Binding Sites↗
PubMed1984

Color specular microscopy of disorders involving the corneal epithelium.

Color specular microscopy, a noninvasive, in vivo microscopic technique, was utilized to study the corneal epithelium in 17 patients including eight with keratoconus, seven with bullous keratopathy, and two with Fuchs' corneal dystrophy. Color specular microscopy was also performed on rabbit corneas with experimental surgical trauma. Changes observed by specular microscopy in these diseased states correlated with alterations noted by light microscopy and scanning and transmission electron microscopy. Specular microscopy can provide detailed in vivo cellular morphology of the ocular surface, obviating the need for tissue biopsy. Thus, specular microscopy is a valuable diagnostic technique available for the clinician to monitor changes of the diseased ocular surface.

Animals↗
PubMed1984

Lipopolysaccharide changes in impermeability-type aminoglycoside resistance in Pseudomonas aeruginosa.

Clinical isolates of Pseudomonas aeruginosa were examined for the basis of impermeability-type aminoglycoside resistance. Two apparently related burn isolate strains with high-level (strain 8803) and low-level (strain 13934) gentamicin resistance each had a plasmid. Transformation of the plasmid from either strain to P. aeruginosa PAO503 resulted in low-level gentamicin resistance. No mechanism for this resistance could be determined. Low-level gentamicin and streptomycin resistance from strain 8803 (but not 13934) was transduced with phage E79.tv2 to PAO503 without transfer of plasmid DNA. Transductants like strain 8803 showed absence or reduction of the lipopolysaccharide (LPS) "ladder" pattern of PAO503, had a change in chemical composition of LPS, and, like strain 8803, had a reduced capability to accumulate streptomycin. Comparison of the resistant clinical isolates 8803 and P10 with the apparently related but less-resistant strains 13934 and P10R, respectively, showed the latter strains had LPS ladder patterns and the former strains did not. Strain 8803 had normal outer membrane protein profiles, electron transport components, and transmembrane electrical potential relative to PAO503 and has been previously shown to have no detectable gentamicin-modifying enzymes and normal protein synthesis. We conclude that low-level impermeability-type aminoglycoside resistance in P. aeruginosa results from conversion of smooth LPS to superficial or deeper rough LPS phenotypes. High-level resistance apparently results from a plasmid-specified, but as yet unknown, mechanism combined with the preceding change in LPS structure.

Aminoglycosides↗
PubMed1984

Suppression by diets rich in fish oil of very low density lipoprotein production in man.

The highly polyunsaturated fatty acids in fish oils lower the plasma triglyceride concentration. We have studied the effect of a diet rich in fish oil on the rate of production of the triglyceride-transporting very low density lipoprotein (VLDL). Seven subjects, five normal and two with hypertriglyceridemia received up to 30% of daily energy needs from a fish oil preparation that was rich in eicosapentaenoic acid and docosahexaenoic acid, omega-3 fatty acids with five and six double bonds, respectively. Compared with a diet similarly enriched with safflower oil (in which the predominant fatty acid is the omega-6 linoleic acid, with two double bonds), the fish oil diet lowered VLDL lipids and B apoprotein concentrations profoundly. High density lipoprotein lipids and A1 apoprotein were also lowered, but the effect on low density lipoprotein (LDL) concentration was inconsistent. The daily production or flux of VLDL apoprotein B, calculated from reinjected autologous 125I-labeled lipoprotein, was substantially less in six subjects studied after 3 wk of fish oil, compared with after safflower oil. This effect on flux was more consistent than that on the irreversible fractional removal rate, which was increased in the four normolipidemic but inconsistent in the hypertriglyceridemic subjects. This suggests that fish oil reduced primarily the production of VLDL. The daily production of VLDL triglyceride, calculated from the kinetics of the triglyceride specific radioactivity-time curves after [3H]glycerol was injected, also showed very substantial reductions in five subjects studied. The marked suppression in VLDL apoprotein B and VLDL triglyceride formation was found not to be due to diminished plasma total free fatty acid or plasma eicosapentaenoic flux, calculated during constant infusions of [14C]eicosapentaenoic acid and [3H]oleic acid in four subjects. In two subjects there was presumptive evidence for substantial independent influx of LDL during the fish oil diet, based on the precursor-product relationship between the intermediate density lipoprotein and LDL apoprotein B specific radioactivity-time curves.

Adult↗
PubMed1984

Cardiopulmonary resuscitation at the Singapore General Hospital.

Effective use of Cardiopulmonary Resuscitation (CPR) saves lives both in and out of hospitals. Yet, in Singapore, this practical skill is rarely taught even within the medical community. Observations from a CPR pilot training programme at the Singapore General Hospital expose this glaring deficiency in our health system. Urgent remedial measures are needed.

Education, Continuing↗
PubMed1983

Neonatal methadone withdrawal. Effect of two treatment regimens.

Thirty-one infants exposed to methadone in utero who required pharmacologic treatment for withdrawal symptoms were randomly assigned to a paregoric or phenobarbital treatment group. Seven infants had symptoms too mild to require treatment. Respiratory rate, blood pH, PCO2, systolic BP, and serum thyroxine concentrations were measured on the 4th, 7th, and 14th days of life. Platelet counts were performed on the seventh and 14th days of life, and urinary catecholamine excretion was measured on the sixth day of life. Rates of weight gain were recorded during the second and third weeks of life. With the exception of a slightly higher blood PCO2 level in the phenobarbital-treated infants on day 7, no significant intergroup differences were observed in the treated infants. Paregoric-treated infants required a significantly longer period of treatment than phenobarbital-treated infants (22 v 17 days). This may have been due, at least in part, to the prolonged half-life and relatively high blood levels of phenobarbital present after cessation of therapy.

Blood Pressure↗
PubMed1983

The rate of starch hydrolysis in vitro does not predict the metabolic responses to legumes in vivo.

The aim of this study was to determine whether legumes in a physical form which is rapidly digested in vitro give rise to proportionately greater metabolic responses in vivo than legumes which are slowly digested in vitro. Samples of cooked whole and ground lentils were incubated in vitro with pancreatic amylase for 30 min and the percentage starch hydrolysis determined. Grinding the lentils before cooking resulted in a 5-fold increase in the rate of starch hydrolysis (whole lentils 12.1%, ground lentils 60.9%). For the in vivo studies six healthy, young, lean subjects consumed two test meals containing 50 g starch: whole lentils and lentils that had been ground finely before cooking. Postprandial glucose and insulin responses were measured over 4 h. Peak glucose and insulin responses occurred 60 min postprandially for the whole lentils and 30 min postprandially for ground lentils. Although the increase in plasma glucose after ground lentils (1.6 mM) was significantly higher (p less than 0.025) than that after whole lentils (0.9 mM), there was no difference in the magnitude of the insulin responses. These results indicate that, unlike for cereals, the rate of intestinal starch hydrolysis is not the major factor determining the metabolic responses to legumes. By virtue of their low postprandial glucose and insulin responses, irrespective of their physical form and digestibility, legumes would appear to be ideal for inclusion in the diet of diabetics.

Adult↗
PubMed1983

A conceptual approach to the development of motivational strategies.

Teachers in both general and professional education are well aware of the importance of motivation as the basis of effective teaching. Heidgerken maintains that a major problem that faces nursing educators is to select the right type of motivation and to know how to effect motivation. The authors propose a conceptual model for developing strategies to deal with motivational problems. This model is an application of Vroom's value/expectancy theory and Rotter's social learning theory, and is based on the premise that nursing faculty are in strategic positions to enhance student motivation for learning by manipulating variables that are believed to influence motivation. These suggested strategies include: enhancing student's need value by rewarding them with rewards that they value the most; increasing student's perceptions of a strong link between performance and rewards; providing students with consistent and clear role perceptions; improving student satisfaction towards learning.

Achievement↗
PubMed1983

Anti-inflammatory and antiarthritic evaluation of acetaminophen and its potentiation of tolmetin.

The data obtained from 5-day and long-term evaluations of acetaminophen (APAP) using the adjuvant arthritis rat model, demonstrated the anti-inflammatory and antiarthritic activities of APAP. The analgesic, anti-inflammatory and antiarthritic activities of tolmetin were significantly potentiated when used in combination with APAP. Inasmuch as APAP, up to 2.0 mg/kg/day, does not produce ulcerogenic effects and does not potentiate the ulcerogenic potency of tolmetin, the therapeutic safety of the APAP-tolmetin combination is much superior to tolmetin alone as determined by these preclinical evaluations. Further studies will be necessary to identify the existence of other side effects, which may or may not be potentiated, before any clinical studies can be contemplated.

Acetaminophen↗
PubMed1982

Problems in teaching ethnic minority nursing students.

Ethnic minority nursing students are different from the majority of white students, and approaches that nursing faculties use in teaching them must also be different. Teaching these students is sometimes viewed by many faculties as a threat. However, if difficulties are recognized early and handled efficiently, educating the ethnic minority students can instead become a challenge to the nurse educators. The authors propose some ways to deal with the existing or potential difficulties that arise from teaching these students. These suggestions are made with major emphasis on the student, the teaching process, and the curriculum. Ethnic minority students need to be helped to develop a positive self-esteem, a sense of worthiness and a feeling of equality and acceptance. Nursing faculties are charged with this responsibility and must be committed to it. Furthermore, nursing curricula need to take into account cultural diversity, to increase students' understanding of the impact of cultural diversities on health care. This paper presents a viewpoint from which important questions related to problems associated with teaching minority students, could be raised.

Adult↗
PubMed1981

The selection and organization of curricular experience in nursing.

Curriculum is the educational design of learning experiences for the students. Curricular experiences include course content as well as learning activities. The selection and organization of curricular experiences must also reflect the philosophy of the school. The identifying and organizing of curricular experiences begins with the analysis of curriculum objectives. The most commonly used approach in selecting learning experiences is the logical approach in which the process is treated as content in curriculum development. This paper attempts to analyse the selection and organization of the first year curricular experiences of the proposed curriculum by applying the logical approach. The proposed curriculum is designed for a 2-year diploma school of nursing. Nursing is offered as a continuum of increasing complexity throughout the three semesters of each year. The curricular framework is based on the health field concept; curricular experiences are selected and organized in accordance with this concept. Courses related to the four elements of the health field concept become mandatory classes for all students. Similarly clinical experience is organized so that a total integration of knowledge from these four elements is enhanced. The first year students study the general aspects of health and health field concept; the nursing process; helping relationships and selected skills necessary for meeting patient's physiological needs. The last semester of the first year is a synthesis practicum proposed to integrate principles and theories which the students have acquired previously and to apply them to the practice of nursing.

Curriculum↗