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Biomedical subjects

S J Williams

Publications and source records attributed to S J Williams.

At least 145 records · Page 8Linked to original sources
PubMed1979

The relationship between utilization of mental health and somatic health services among low income enrolees in two provider plans.

Mental health services were included in comprehensive benefits available with no out-of-pocket expenses to enrollees in the Seattle Prepaid Health Care Project. This study was designed to examine the characteristics of users as compared to nonusers of mental health services and to examine the possibility of lower use of somatic health services attributable to the availability of mental health services. Two enrollee groups were studied: one group included enrollees with at least one mental health service (MH-U) and the other included those with some somatic utilization but without mental health utilization (MH-NU). Results indicated that mental health users were different from nonusers based on sociodemographic, health status, and prior utilization measures. Further, the mental health utilizers consumed more somatic services than other enrollees, even controlling for background variables. The visit and admission rates for the MH-U group were 2.4 times that of the MH-NU group, and total inpatient and outpatient costs were three times as high. On all three comparisons, approximately 60 per cent of the difference was accounted for by mental health utilization and by differences in sociodemographic and health status characteristics. The remaining 40 per cent could not be explained, but there is a suggestion that the higher utilization occurred for conditions where medical care is discretionary.

Adolescent↗
PubMed1979

Methods of studying lobar and segmental function of the lung in man.

Making the decision whether a patient with chest disease can undergo lung surgery may be easier if the anatomical extent of the disease and the functional effects of resection can be estimated. Although information can be gained by non-invasive physiological studies of lung function of a routine kind, these cannot define the anatomical extent of the disease or distinguish the relative influence of affected and unaffected parts as estimates of lung function. Whole lung ventilation and perfusion scans provide immediate topographic information but have limited resolution and anatomical accuracy, particularly when the architecture of the lung is disturbed by disease. Bronchoscopy gives direct visual information about the more central airways but little or none about the function of the areas they serve. This paper gives brief descriptions of a series of procedures which could help in assessing the feasibility of lung surgery. The size, shape and volumes of individual lungs and lobes can be estimated from plain chest radiographs. Corresponding information about individual segments, and about lobes not delineated by normal X-ray, can be obtained using radio-active krypton 81m and a gamma camera during otherwise routine fibreoptic bronchscopy segments can be determined by simple single-breath manoeuvres at bronchoscopy using a respiratory mass spectrometer. The radio-isotope and spectrometric tests can be obtained in the same breath. The spectrometric tests can be recorded from more than one part of the lung within the same breath. All of the procedures give information in terms of anatomical units of interest to the surgeon.

Adult↗
PubMed1978

An evaluation of the tuberculosis agglutination test.

The tuberculosis agglutination titre as described by Nicholls (1975) was measured without prior knowledge of the diagnosis in 27 patients with open pulmonary tuberculosis, 100 patients with other diseases and 14 control patients with no apparent disease. Reproducibility of the test, as judged by repeat estimations on split samples, was poor. When attempting to distinguish between the disease categories the test gave 29% false negatives in patients with tuberculosis and 52% false positives in patients with other disease. Therefore the tuberculosis agglutination titre cannot be recommended for use in distinguishing tuberculosis from other conditions.

Agglutination Tests↗
PubMed1978

A causal model of health services for diabetic patients.

A causal model of health services which includes patient and provider variables, perceived access to care, utilization of services, continuity of care, technical quality of the care process, technical quality of the care outcome, and patient satisfaction is applied to a group of diabetic patients enrolled in the Seattle Prepaid Health Care Project. The enrollees received comprehensive health services at zero out-of-pocket cost from either a prepaid group practice plan or an independent practice plan. Surveys were periodically conducted to determine health status, satisfaction, and demographic characteristics of the enrollees; utilization of services was monitored throughout the experiment. The causal model is operationalized through the use of path analysis. Significant relationships (p less than or equal to .10) were established between satisfaction and perceived access to care, family size, sex, and professional qualifications of the provider; between outcome of care and health status, female education, and physician performance; between physician performance and professional qualifications; between continuity of care and health status and female education; between utilization and perceived access, specialty of provider, and provider system; and between access to care and provider system. The policy implications of the results are discussed.

Consumer Behavior↗
PubMed1977

A vital statistics-based procedure for estimating conception rates.

A method for estimating conception rates, using vital statistics data, is developed and applied to data on five-year age groups of California women for 1971. The approach is deterministic and allocates total exposure time to the known pregnancy outcomes of live birth, spontaneous abortion, and induced abortion. The population at risk is defined to exclude women who are known to be sterile or sexually inactive. Early fetal loss, premarital conception, and contraceptive use are taken into account. Estimates are made of the fecundability which would obtain if no contraception were used.

Abortion, Induced↗
PubMed1976

Bronchodilator effect of delta1-tetrahydrocannabinol administered by aerosol of asthmatic patients.

Ten volunteer inpatient asthmatics in a steady state were given a single inhalation of an aerosol (63 mul) delivered in random order, on each of three consecutive days, in the laboratory of a respiratory unit. Before, and for one hour after treatment the pulse, blood pressure (lying and standing), forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), peak flow rate (PFR), and self-rating mood scales (SRMS) were recorded. Treatments were placebo-ethanol only; delta1-tetrahydrocannabinol (THC) 200 mug in ethanol; or salbutamol 100 mug (Ventolin inhaler), administered double blind. Salbutamol and THC significantly improved ventilatory function. Maximal bronchodilatation was achieved more rapidly with salbutamol, but at 1 hour both drugs were equally effective. No cardiovascular or mood disturbance was detected, and plasma total cannabinoids at 15 minutes were undectable by radioimmunoassay. The mode of action of THC differs from that of sympathomimetic drugs, and it or a derivative may make a suitable adjuvant in the treatment of selected asthmatics.

Albuterol↗
PubMedDate not supplied

Matrix metalloproteinase inhibition protects hepatic integrity in hemorrhagic shock.

Hemorrhagic shock increases cytokines, such as tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6), and compromises hepatic function and integrity. The production of TNF-alpha involves a cascade reaction regulated by the enzyme TNF-alpha convertase. The purpose of this study was to examine the effects of matrix metalloproteinase inhibitor (MMPI) (British Biotech 1101) in vivo on hepatic integrity in a rat model of hemorrhagic shock. Sprague-Dawley rats (n = 26) were divided as follows: hemorrhagic shock (group 1) and hemorrhagic shock plus MMPI (group 2). TNF-alpha, IL-6, and hepatic membrane potentials (Em) were obtained. The administration of MMPI significantly decreased TNF-alpha levels (P <0.001) and stabilized the membrane potential at -30 mV as compared to the depolarized membrane potential at -20 mV for hemorrhagic shock without MMPI. IL-6 levels were not affected by the MMPI. This study demonstrates that MMPI decreases TNF-alpha levels and protects hepatic integrity in hemorrhagic shock, as evidenced by the stabilization of the membrane potential, independent of the mean arterial pressure. The hepatic protection is closely related to the decrease in TNF-alpha levels seen in the portal circulation.

Animals↗
PubMedDate not supplied

Comparative stability, sensitivity and specificity studies with different lots of Blastomyces dermatitidis yeast and mycelial lysate antigens.

Comparative studies were performed to assess the stability and lot-to-lot variation of Blastomyces dermatitidis yeast and mycelial phase lysate antigens. Four lots were prepared from each growth phase of B. dermatitidis strain T-58 (canine isolate) during a 14-month period. Serum specimens from dogs with blastomycosis, histoplasmosis, coccidioidomycosis, cryptococcosis and aspergillosis were assayed for antibody content using an alkaline phosphatase enzyme-linked immunosorbent assay (ELISA). The four lots of the yeast phase reagents were similar with respect to sensitivity and specificity, and the absorbance readings were approximately four times greater with sera from dogs with blastomycosis than with histoplasmosis or coccidioidomycosis. Even less cross-reactivity was evidenced when the sera from dogs with cryptococcosis and aspergillosis were assayed. In contrast, the four lots of the mycelial lysate reagents were considerably less reactive and more cross-reactive than the yeast phase antigens and, as above, the four reagents retained their activity after prolonged storage. Therefore the results indicated that the lysate antigens exhibited a great deal of stability and lot-to-lot variations in activity were not observed.

Animals↗