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Biomedical subjects

C S Ray

Publications and source records attributed to C S Ray.

16 recordsLinked to original sources

Epidemiology of betel quid usage.

Betel quid chewing is an ancient practice common in many countries of Asia and among migrated communities in Africa, Europe and North America. It enjoys complete social acceptance in many societies and is also popular among women. In its most basic form, betel quid consists of betel leaf (Piper betel), areca nut, the main psychoactive ingredient, and slaked lime (calcium hydroxide). Areca nut is said to be the fourth most commonly used psychoactive substance in the world, after caffeine, nicotine and alcohol. There are a great variety of ingredients and ways of preparing betel quid in different countries. In some, particularly in India, tobacco is added to the quid. In recent years, commercially-manufactured non-perishable forms of betel quid (pan masala or betel quid mixtures and gutka), not containing betel leaf, have been marketed. Within a short period of about 2 decades, this industry has risen in value to several hundred US million dollars. Use of areca nut in any form is not safe for oral health; the use of commercially manufactured forms seems even riskier.

Areca↗

Pulmonary edema associated with scuba diving : case reports and review.

Acute pulmonary edema has been associated with cold-water immersion in swimmers and divers. We report on eight divers using a self-contained underwater breathing apparatus (scuba) who developed acute pulmonary edema manifested by dyspnea, hypoxemia, and characteristic chest radiographic findings. All cases occurred in cold water. All scuba divers were treated with complete resolution, and three have returned to diving without further episodes. Mechanisms that would contribute to a raised capillary transmural pressure or to a reduced blood-gas barrier function or integrity are discussed. Pulmonary edema in scuba divers is multifactorial, and constitutional factors may play a role. Physicians should be aware of this potential, likely underreported, problem in scuba divers.

Acute Disease↗

Measurement of synovial fluid and serum concentrations of the 846 epitope of chondroitin sulfate and of carboxy propeptides of type II procollagen for diagnosis of osteochondral fragmentation in horses.

OBJECTIVE: To determine whether serum or synovial fluid concentrations of chondroitin sulfate epitope 846 and carboxy propeptides of type II collagen (CPII) can be used to diagnose osteochondral fragmentation (OC) in horses. ANIMALS: 38 horses with unilateral OC of the radiocarpal (n = 31) or intercarpal (33) joints and 8 clinically and radiographically normal horses. Procedures-For horses with OC, serum and synovial fluid concentrations of epitope 846, CPII, and keratan sulfate (KS) were determined, along with synovial fluid WBC counts and total protein concentrations. Serum epitope 846, CPII, and KS concentrations were measured in control horses. RESULTS: Synovial fluid epitope 846 and total protein concentrations were significantly higher in the joints with OC than in unaffected joints, but CPII and KS concentrations and WBC counts were not. Synovial fluid total protein and 846 epitope concentrations were linearly related to grade of OC. Serum epitope 846 and CPII concentrations were significantly higher in horses with OC than in control horses. Discriminant analysis allowed 27 of 34 (79%) horses to be correctly classified as having or not having OC on the basis of serum epitope 846 and CPII concentrations. CONCLUSIONS: Results suggest that serum and synovial fluid concentrations of epitope 846 and CPII are associated with OC. Increases in concentrations of epitope 846 and CPII suggest that increased synthesis of cartilage aggrecan and type II procollagen may be associated with OC. CLINICAL RELEVANCE: Measurement of serum epitope 846 and CPII concentrations may be useful in the diagnosis of OC in horses.

Animals↗

An evaluation of dipstick-dot immunoassay in the detection of antibodies to HIV-1 and 2 in Zimbabwe.

There is a need, in many developing countries, for simple and inexpensive HIV serology tests for use at the district level of health care. The Programme for Appropriate Technology in Health has developed a simple dipstick ELISA to detect antibodies to HIV-1 and 2, at a cost considerably lower than current ELISAs, which requires no specialized washing or reading equipment. In order to evaluate this dipstick under local conditions we used a panel of 546 sera selected from frozen stocks maintained by the Zimbabwe AIDS Prevention Project in Harare, Zimbabwe. Prior to storage, the sera had been tested by Abbott recombinant peptide HIV-1 and 2 ELISA and Enzygnost synthetic peptide HIV-1 and 2 ELISA. The panel included sera that were positive by both (including symptomatics and asymptomatics), negative by both, and sera showing discrepant test results. The panel was not representative of a "normal' batch of sera in Zimbabwe, and in particular included an abnormally high number of sera showing discrepant results. Thawed sera were retested using the Abbott recombinant peptide HIV-1 and 2 ELISA and concurrently with the synthetic peptide ICL-Dipstick ELISA. Both the sensitivity and specificity of the ICL Dipstick exceeded 99% when using sera that were positive or negative in all 3 plate ELISAs as the gold standard. When using sera that gave discrepant results between the two pre-storage ELISAs, most results with the ICL Dipstick concurred with findings from other test systems, including Western blot and p24 antigen detection. Considering the accuracy, low cost and case of operation of the ICL Dipstick ELISA, this test can be recommended for use for the rapid detection of antibodies to HIV at district level in developing countries.

Enzyme-Linked Immunosorbent Assay↗

Behaviour patterns which may predispose to HIV infection or further transmission and possible intervention strategy in the City of Harare. Part II.

The proportion of people with AIDS is increasing rapidly in Zimbabwe. Several strategies have been adopted to check the further spread of the disease. This paper discusses the behaviour patterns which may predispose to HIV infection and possible intervention strategies that may be taken in the City of Harare. Over a third (33.9 pc, n = 1,526) of the married respondents reported that they were living separately from their spouses. There was a high proportion (76.6 pc, n = 564) of single respondents who admitted to engaging in premarital sex. Fifteen pc of total respondents were engaging in casual sex. The proportion of single respondents (31.2 pc) engaging in casual sex was higher than among the married (11.1 pc). More single respondents (10.9 pc) had been paid for sex than the married (4.1 pc) whilst the proportion that had been paid for sex was similar for the single (21.2 pc) and the married (22.9 pc). The median age for starting sex was 17 years (range = three to 26) for the single and 18 years (range = four to 35) for the married respondents. Sixteen pc stated that they had an STD in 1989. Condom usage was low with only 9.2 pc always using a condom. Forty eight pc of the married respondents who have engaged in casual sexual relationships never use condoms. The main source of information on AIDS/HIV was the radio (74 pc). Most parents (66 pc) had not talked about AIDS to their children.

Adolescent↗

Knowledge and attitudes on AIDS relevant for the establishment of community care in the city of Harare.

Part I: Because of the increasing number of people with the HIV infection or AIDS, health resources and facilities are becoming over burdened. Many projects are looking towards involving communities more in caring and supporting those living with HIV/AIDS. In view of this, features of knowledge and attitudes have been drawn out of a main study on knowledge, attitudes and practices on 2 109 respondents in the City of Harare, to demonstrate areas where urgent preparation is needed to facilitate community care. The majority of respondents (96 pc) were aware that AIDS is a sexually transmitted disease. About 70 pc of the respondents thought that there were many people infected with HIV in Zimbabwe. Most of the respondents (83.3 pc) were frightened by the idea of catching AIDS. However, 82 pc would want to know if they are infected with the AIDS virus. About nine pc of the respondents said that they would commit suicide on discovering that they had HIV. Only 10 pc would have another child after becoming infected. A quarter of the respondents would not be supportive of people with AIDS. They stated that they would evict lodgers with AIDS, would avoid either neighbour, coworker or school mate with AIDS. People were generally more willing to look after their own children (76 pc) and less supportive of other relatives (68 pc) who had AIDS. Gender differences are also highlighted.

Adolescent↗

Therapeutic review: tuberculosis.

Tuberculosis (TB) is increasing in Zimbabwe and other countries in Africa and world-wide. TB treatment and control face new difficulties including the impact of the HIV epidemic and drug resistance. There is now abundant evidence that six-month regimens are highly effective and, by improving compliance, can improve results and the cost-effectiveness of therapy. Intermittent therapy reduces drug costs and allows for the possibility of complete supervision. The optimal management of the HIV-infected TB patient has not yet been established but an increased rate of drug reactions suggests that standard treatment should be reassessed.

Antitubercular Agents↗

High resolution computed tomography and lung function in asbestos-exposed workers with normal chest radiographs.

Asbestos-exposed persons with normal chest radiographs can demonstrate parenchymal abnormalities on high resolution computed tomography (HRCT). We reviewed the HRCT, clinical presentation, and results of pulmonary function tests in 169 asbestos-exposed workers with normal chest radiographs (ILO less than 1/0). The HRCT was normal or near normal in 76 subjects (Group 1), abnormal but indeterminate for asbestosis in 36, and abnormal and suggestive of asbestosis in 57 (Group 2). The indeterminate subjects were excluded from further analysis. The subjects in Groups 1 and 2 were not significantly different in their duration of asbestos exposure, latency, smoking history, or in measurements of airflow obstruction (FEV1/FVC% and %FEV1). Both the vital capacity percent predicted and diffusing capacity percent predicted were significantly lower in the abnormal subjects (Group 2) than in the normal subjects (Group 1) (79.0 versus 86.2, p = 0.005; 78.2 versus 87.1, p = 0.024; independent t test). We conclude that in asbestos-exposed subjects with normal chest radiographs, HRCT can identify a group of subjects with significantly reduced lung function indicative of restrictive lung disease when compared with a group with normal or near-normal HRCT.

Adult↗

Asbestos-related pleural and parenchymal fibrosis: detection with high-resolution CT.

Twenty-nine subjects with occupational asbestos exposure and clinical asbestosis were examined with high-resolution computed tomography (HRCT) to determine its sensitivity, relative to that of conventional computed tomography (CT), for detection of benign asbestos-related disease. Thin-section HRCT scans were obtained at five discrete levels through the mid and lower thorax in both prone and supine positions. The same technique was used in 34 age-similar control patients. Parenchymal abnormalities were seen most frequently in the posterior portion of the lung bases in the asbestos-exposed subjects. HRCT prone scans enabled basal structural abnormalities to be reliably distinguished from gravity-related physiologic phenomena in 25 asbestos-exposed subjects. HRCT was more sensitive than CT in detection of both pleural and parenchymal fibrosis. In subjects with clinical asbestosis, HRCT demonstrated parenchymal abnormality in 96%, compared with 83% for CT. Similarly, pleural thickening was shown in 100% of subjects at HRCT, compared with 93% at CT. HRCT could be an important adjunct in the evaluation of asbestos-related pleuroparenchymal fibrosis. An HRCT study including prone scans is a sensitive, reliable means of detecting thoracic abnormalities in asbestos-exposed individuals.

Adult↗

Asbestos-related focal lung masses: manifestations on conventional and high-resolution CT scans.

In 260 asbestos-exposed individuals evaluated by means of computed tomography (CT), 43 unsuspected pulmonary masses were found in 27 individuals. The masses included fissural pleural plaques (n = 10), dense fibrotic bands (n = 3), round atelectasis (n = 11), carcinomas (n = 3), and other presumed benign masses (n = 16). The most helpful features in the diagnosis of rounded atelectasis with CT were (a) contiguity to areas of diffuse pleural thickening, (b) a lentiform or wedge-shaped outline, (c) evidence of volume loss in the adjacent lung, and (d) a characteristic "comet tail" of vessels and bronchi sweeping into the margins of the mass. Less advanced areas of focal atelectasis had fewer classic features. Intrafissural pleural plaques were readily identified with high-resolution CT. In asbestos-related masses, the demonstration of stability over time is necessary. Careful interpretation of CT and high-resolution CT features and close surveillance can obviate the need for biopsy in the majority of instances.

Asbestos↗

High-resolution CT of benign asbestos-related diseases: clinical and radiographic correlation.

We prospectively analyzed benign asbestos-related pleural and parenchymal abnormalities on high-resolution CT scans and correlated them with clinical diagnoses in 100 asbestos-exposed workers. All subjects had high-resolution CT scans in conjunction with conventional CT at the time of clinical evaluation. To evaluate for asbestosis, we ranked high-resolution CT scans as high, intermediate, or low probability of asbestosis on the basis of the multiplicity and extent of observed parenchymal changes. By linear regression analysis, the most distinctive high-resolution CT features of asbestosis included thickened nondependent interstitial short lines and parenchymal bands. In 45 subjects satisfying clinical criteria of asbestosis, high-resolution CT probability of asbestosis was high in 38 (84%), intermediate in five (11%), and low in two (4%). In 20 (36%) of 55 subjects without clinical asbestosis, parenchymal abnormalities indicative of a high probability of asbestosis were observed on high-resolution CT. High-resolution CT probability scores had a strong positive correlation with chest radiographic profusion scores (p less than .0001) and asbestos-related pleural thickening (p less than .0001). Significant inverse correlations were seen with forced vital capacity (p less than .006) and single-breath diffusing capacity (p less than .03), both functional measures of restrictive interstitial lung disease. Neither clubbing nor rales were sufficiently prevalent to have statistical correlation with high-resolution CT scores. High-resolution CT is sensitive in detecting both pleural and parenchymal abnormalities in the asbestos-exposed subject. Asbestos-related pleural changes are observed more frequently on high-resolution CT than on conventional CT or chest radiography. The probability of asbestosis based on high-resolution CT parenchymal features has a significant correlation with existing clinical determinants of disease, and high-resolution CT can detect abnormality when other methods are not diagnostic.

Adult↗

Effects of obesity on respiratory function.

Obesity, because it alters the relationship between the lungs, chest wall, and diaphragm, has been expected to alter respiratory function. We studied 43 massively obese but otherwise normal, nonsmoking, young adults with spirometry, lung volume measurement by nitrogen washout, and single-breath diffusing capacity for carbon monoxide (DLCO). Changes in respiratory function were of two types, those that changed in proportion to degree of obesity--expiratory reserve volume (ERV) and DLCO--and those that changed only with extreme obesity--vital capacity, total lung capacity, and maximal voluntary ventilation. When compared with commonly used predicting equations, we found that mean values of subjects grouped by degree of obesity were very close to predicted values, except in those with extreme obesity in whom weight (kg)/height (cm) exceeded 1.0. In 29 subjects who lost a mean of 56 kg, significant increases in vital capacity, ERV, and maximal voluntary ventilation were found, along with a significant decrease in DLCO. Because most subjects fell within the generally accepted 95% confidence limits for the predicted values, we concluded that obesity does not usually preclude use of usual predictors. An abnormal pulmonary function test value should be considered as caused by intrinsic lung disease and not by obesity, except in those with extreme obesity.

Adult↗

Pulmonary function abnormalities in patients with CT-determined emphysema.

The CT quantification of both the extent and severity of emphysema was undertaken in 30 subjects. The CT scans at five preselected anatomic levels were analyzed using two methods. Correlation of the results of the CT methods were with pulmonary function results of airway obstruction and alveolar diffusion for carbon monoxide. Analysis by direct observation of the CT scans gave insignificantly different results for a complex grid method of analysis. The emphysema score with the observational method had a positive correlation with airflow obstruction (r = -0.817) as did the score with the grid method (r = -0.873). The diffusing capacity for carbon monoxide also correlated with both emphysema scores. The CT methods for quantifying emphysema correlate closely with functional abnormalities. As previously demonstrated with pathological assessment of lung slices for emphysema, direct observation of CT scans is as precise as a more complex grid method.

Aged↗