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Biomedical subjects

C Power

Publications and source records attributed to C Power.

34 records · Page 2Linked to original sources

Pulmonary disease progress in sarcoid patients with and without bronchoalveolar lavage collagenase.

To assess the usefulness of bronchoalveolar lavage (BAL) collagenase measurement in gauging disease severity and outcome in sarcoidosis, we analyzed BAL fluids from 84 patients with sarcoidosis for collagenase and monitored disease progress in these patients for a minimum of 12 months. Twenty patients (24%) were found to have BAL collagenase activity on initial evaluation (collagenase-positive group). Compared with patients without BAL collagenase (collagenase-negative group), the collagenase-positive group had (1) a higher proportion of BAL suppressor T cells (p less than 0.03); (2) a lower helper-suppressor T-cell ratio (p less than 0.002); (3) lower mean percent predicted FEV1, FVC, and DLCO levels (p less than 0.05); and (4) a higher proportion of patients with advanced (Stage 4) disease on chest roentgenogram (p less than 0.001). Significant differences were also observed between the collagenase-positive and collagenase-negative groups during follow-up. A higher proportion (55%, n = 11) of collagenase-positive patients required corticosteroid therapy than did collagenase-negative patients (26%; n = 17; p less than 0.025). Of those who remained untreated, pulmonary function tended to decrease in the collagenase-positive group, whereas mean pulmonary function levels actually improved in the collagenase negative group (p less than 0.05). Of those who required therapy, mean percent predicted FVC and DLCO levels improved significantly after treatment in the collagenase-negative group (p less than 0.01 and p less than 0.05, respectively), whereas an improvement in percent predicted FVC levels only (p less than 0.01) was observed in the collagenase-positive group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones

The relationship between bronchial immunopathology and hyperresponsiveness in asthma.

Physiological and Immunopathological parameters were investigated in 15 patients with diagnosed asthma, and 6 non-asthmatics presenting with other chest symptoms. The 15 symptom-free asthmatics expressed bronchohyperresponsiveness with a mean provocative dose producing a 20% fall in forced expiratory volume in one second (PD20FEV1) of 1 mg histamine. None of the non-asthmatics responded to 16 mg histamine. Twenty four hours later bronchoscopy was performed and endobronchial biopsies were obtained. Histological staining of frozen biopsy sections revealed a mononuclear cell infiltrate in all 15 asthmatics, while only 1 of the 6 non-asthmatics showed mild inflammation. Monoclonal antibodies were used to identify subsets of lymphocytes, activation markers, macrophages, and HLA-DR expression within the peribronchial infiltrates. In all samples, activated T-cells and macrophages were identified and HLA-DR expression was found to be raised, but the CD4: CD8 ratio was highly variable. No clear relationship was found between cellular distribution and measured lung function parameters. A highly significant correlation was found between the level of HLA-DR expression on the infiltrating cells (quantified microdensitometrically) and bronchial hyperresponsiveness. These results show for the first time that a chronic T-cell-mediated immune response is present in the bronchial tissue of asymptomatic asthmatics, and that the HLA-DR expression promoted correlates with the hyperresponsive status. These data promote the hypothesis that a T-cell-mediated response contributes to a predisposition to bronchial hyperresponsiveness in asthmatics.

Adolescent

Adolescent decision-making: the development of competence.

This article reviews evidence relating to the development of competence in decision-making during adolescence. The review focuses on cognitive aspects of decision-making and discusses nine indicators of competence: choice; comprehension; creativity; compromise; consequentiality; correctness; credibility; consistency; and commitment. The evidence suggests that by the age of 15 years many adolescents show a reliable level of competence in metacognitive understanding of decision-making, creative problem-solving, correctness of choice, and commitment to a course of action. Young adolescents (12-14 years) are less able to create options, identify a wide range of risks and benefits, foresee the consequences of alternatives, and gauge the credibility of information from sources with vested interests. No evidence is available relating to age differences in willingness to make choices, devise compromises, and show consistency of choices. Barriers to achieving competence in decision-making during adolescence include attitudinal constraints (e.g. beliefs about the proper age for making decisions), peer group pressures to conformity, breakdowns in family structure and functioning, and restricted legal rights to make important personal decisions (e.g. to donate blood or body tissue).

Adolescent

Predicting traffic injuries in childhood: a cohort analysis.

Data from a sample of more than 16,000 children born in the United Kingdom in 1958 were studied to identify factors that may affect the risk of having a traffic injury. Five sets of risk factors were examined: physical, developmental, educational, behavioral, and family. Information about these factors were obtained systematically from parents, teachers, and physicians when the children were 7 and 11 years of age. The results were related to traffic injuries occurring for the first time during each subsequent 4-year period. Between 8 and 11 years of age, 431 children had a traffic injury requiring medical attention, and between 12 and 16 years the number was 590. Logistic regression analyses identified a small number of factors associated with injuries, which varied according to the age and gender of the child. When all these factors were entered into a final model, only five remained: fidgety, abnormal behavior, and three measures of family disruption or disadvantage--crowding, family problems, and being removed from the family and placed in the care of the local authority. These findings suggest that it may be unwise to place much reliance on "high risk" preventive strategies by measures of this kind. Instead, more emphasis should be placed on community-based passive and environmental strategies.

Accidents, Traffic

HTLV-1 associated myelopathy in Canada.

We report the clinical and laboratory findings of six Canadian patients with progressive myelopathy associated with HTLV-1 infection. The diagnosis was suspected on clinical grounds and supported by serological studies and positive gene amplification. Only five had emigrated from an area endemic for HTLV-1 infection. Tropical spastic paraparesis should be considered in all patients with myelopathy, even those without standard serological markers of HTLV-1 infection. The pathogenesis of this condition and the serological and molecular biological means by which this diagnosis can be made are reviewed.

Adult

Collagenase and fibronectin in bronchoalveolar lavage fluid in patients with sarcoidosis.

Bronchoalveolar lavage fluid from 43 patients with biopsy proved sarcoidosis and 10 control subjects were assayed for fibronectin and collagenase activity. Fibronectin was significantly increased in the group with sarcoidosis and was found to be positively correlated with angiotensin converting enzyme activity, protein concentration, percentage of T cells and helper:suppressor ratios in the lavage fluid. Increased fibronectin in the bronchoalveolar lavage fluid was not related to functional or radiographic indices of interstitial disease and did not identify patients subsequently requiring treatment. Latent collagenase was present in bronchoalveolar lavage fluid from 16 patients with sarcoidosis but not in any control sample. There was no association between the collagenase activity and the cell profiles of the lavage fluid. Yet carbon monoxide transfer factor was decreased in patients with bronchoalveolar lavage fluid collagenase. Ten of 16 patients with bronchoalveolar lavage fluid collagenase had radiographic class III or IV disease and a disease duration of more than two years. On follow up 62% of patients with bronchoalveolar lavage fluid collagenase required subsequent treatment, compared with only 23% of patients without collagenase. These results indicate an association between bronchoalveolar lavage fluid collagenase and progressive, prolonged disease in sarcoidosis, whereas increased bronchoalveolar lavage fluid fibronectin is associated with indices of disease activity.

Adult

Social class and changes in weight-for-height between childhood and early adulthood.

The changes in weight-for-height of those from different social class backgrounds have been examined in the 1958 longitudinal study. Social class differences in the prevalence of overweight and obesity were found to be negligible in childhood but marked by early adulthood, with a greater percentage of overweight and obesity in lower social classes. This different was three-fold among obese men and two-fold among obese women when respondents were classified on the basis of their own occupation. However, a longer term effect of early class backgrounds also emerged. Children from manual backgrounds were more likely to become overweight and obese young adults (7 per cent of those with average weight-for-height at age 7) compared with their non-manual contemporaries (3 per cent). Interestingly, they were also more likely to remain overweight or obese through to early adulthood. Methods preventing weight gain in early life, whilst poorly developed at present, need to ensure that approaches are relevant to young people with lower social class backgrounds.

Adolescent

Autotransfusion: quality of blood prepared with a red cell processing device.

The quality of blood salvaged at operation and prepared with the Dideco Autotrans BT 795 autotransfusion device was compared with that of donor blood in 41 patients having cardiac surgery involving cardiopulmonary bypass. Saved blood had a higher haemoglobin concentration (17.3 v. 13.1 g dl-1; P less than 0.001), a higher 2,3-diphosphoglycerate concentration (5.3 v. 1.1 mmol litre-1; P less than 0.00001), higher white cell count (17.1 X 10(9) litre-1 v. 4.1; P less than 0.00001), higher pH (7.5 v. 6.6; P less than 0.00001) and a more physiological potassium concentration (5.4 v. 8.8 mmol litre-1; P less than 0.00001) than donor blood. Saved blood platelet count was 34.5 X 10(9) litre-1 compared with 146.24 X 10(9) litre-1 (P less than 0.00001) and its heparin concentration was 0.64 u. ml-1. We conclude that this autotransfusor is a useful aid to blood conservation, producing good quality red cells with relatively normal pH and potassium values. However, modification of the centrifugation and washing is required to lessen the high white cell count and heparin concentrations found in the saved blood.

Adolescent

Transformation related expression of glutathione-S-transferase P in rat liver cells.

A neutral isoenzyme of glutathione transferase designated glutathione-S-transferase 7-7, but also referred to as glutathione-S-transferase P (GST-P) is absent from adult rat liver hepatocytes, but expressed at a very early stage in chemically induced in vivo hepatocarcinogenesis. The expression of this enzyme in a range of aflatoxin B1 (AFB1) associated hepatocarcinogenic systems has been examined, including in vivo induced preneoplastic and neoplastic liver tissue, cell lines derived from hepatomas, primary hepatocytes in culture and an immortalized rat liver cell line before and after transformation in vitro either by transfection with ras oncogenes or by treatment with metabolically activated AFB1. Analyses of total cytosol proteins using a polyclonal antibody to GST-P did not detect the presence of GST-P protein in cytosols from control or regenerating liver. A low level of expression was detected in the immortalized, non-transformed epithelial cell line, but a greatly induced level occurred subsequent to transformation of these cells by either of the two techniques used. High levels of the protein were detected in in vivo induced preneoplastic and neoplastic tissues, and in the cell lines derived from them. Total RNA fractions isolated from the various cells or tissues, when examined with a cDNA probe for GST-P mRNA, showed it to be absent from control and regenerating rat liver. It was present at low levels in the untransformed cell line and primary hepatocytes after 48 h in culture, but present at greatest abundance in the in vivo and in vitro transformed cells. The results indicate that the highest elevation in expression of this protein is associated with the stage of definitive malignant transformation in in vitro carcinogenesis, and this could have relevance in defining comparable events in the in vivo multistage sequence.

Aflatoxin B1

Incidence of renal stones in 18 British towns. A collaborative study.

The geographical distribution of renal stones in England and Wales was investigated by selecting 18 towns which encompassed a range of social and economic conditions. Case registers of stone patients were maintained in the hospitals for 2 years; they included out-patients and in-patients. The annual registration rate was 22/100,000 population. Additional information was available for 1980 from Hospital Activity Analysis and the annual rate was 28/100,000. It is suggested that this is the best estimate of the incidence of renal stones in England and Wales. The rate ranged from 56/100,000 in Canterbury to 15/100,000 in Burton-on-Trent. The incidence of renal stones was higher in towns with better social and economic conditions. In comparison, climatic factors, latitude and water hardness were not important determinants of the distribution of renal stones.

Age Factors

Long latency spinal cord dorsum potential; suppression by intrathecal morphine and enkephalin analog.

We have developed a new method which combines intrathecal recordings of spinal cord dorsum potentials (CDPs) with application of drugs to the spinal cord via an intrathecal catheter. With this technique we have discovered a late component (LC) in the CDP which has not been previously described. The LC is evoked by high intensity electrical stimulation of the rat tail. Whereas previous reports describe early components in the CDP evoked by low intensity A-fiber stimulation, ours is the first to describe a late evoked potential implicating C-fiber activation of the cord. Moreover, we show that the LC is blocked by intrathecal application of morphine sulphate or D-Ala-Met-enkephalinamide in a naloxone reversible manner. We postulate that this LC represents, at least in part, the spinal cord evoked response to C-polymodal nociceptive afferent inputs.

Analgesics

Diet and renal stones: a case-control study.

The diets of 51 men with renal stones were compared with those of 94 age-matched controls, using a measured record of all food and drink consumed during 4 days. The mean intakes of three nutrients suspected in the aetiology of renal stones, animal protein, refined carbohydrate (sugar) and dietary fibre, were similar for both cases and controls. However, the cases had a higher intake of ascorbic acid. A greater proportion of cases had low fluid intakes or took no exercise in their leisure time.

Adult

Prevalence of gall stones at necropsy in nine British towns: a collaborative study.

A prospective study of the prevalence of gall stones at necropsy in nine towns in England and Wales showed considerable geographical variations. The age- and sex-standardised prevalence ranged from 20.6% in Ipswich to 9.2% in Wakefield. The distribution of gall stones differed from that of all-cause mortality and was negatively correlated with that of mortality from ischaemic heart disease. Socioeconomic influences related to affluence do not appear to be major determinants of the distribution of gall stones.

Adult