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Biomedical subjects

E C Wright

Publications and source records attributed to E C Wright.

At least 55 records · Page 3Linked to original sources
PubMed1987

Progressive neuropsychologic impairment and hypoxemia. Relationship in chronic obstructive pulmonary disease.

In previous work we showed that patients with chronic obstructive pulmonary disease (COPD) suffered decrements in neuropsychologic functioning suggestive of organic mental disturbance. This study combined data from two multicenter clinical trials to explore the nature and possible determinants of such neuropsychologic change. Three groups of patients with COPD whose hypoxemia was mild (N = 86), moderate (N = 155), or severe (N = 61) were compared with age- and education-matched nonpatients (N = 99). The rate of neuropsychologic deficit rose from 27% in mild hypoxemia to 61% in severe hypoxemia. Various neuropsychologic abilities declined at different rates, suggesting differential vulnerability of neuropsychologic functions to progress of COPD. Multivariate analyses revealed a consistent significant relationship between degree of hypoxemia and neuropsychologic impairment, but the amount of shared variance was small (7%). Increasing age and lower education were also associated with impairment.

Adult↗
PubMed1987

Stochastic curtailing for comparison of slopes in longitudinal studies.

In some clinical trials, rate of change of a physiological function is used as a surrogate for a more serious outcome. We assume an expected change linear in time for each study participant with variation in slopes and intercepts from individual to individual and repeated measures over time for each individual. We also assume that deviations of response for an individual from expected response have zero mean, constant variance, and are uncorrelated. Under these assumptions we describe ways in which stochastic curtailing as defined by Lan, Simon, and Halperin (Commun Stat Seq Anal 1:207-219, 1982) can be implemented in a two-treatment trial for one-sided comparison of slopes in the two groups. Staggered entry is taken into account, as is the possibility that some of an individual's responses are not available; this is assumed to be random. The analysis assumes the number of participants in each group is large and that most individuals have at least two measurements (including baseline value). The possibility that rate of change is not constant and its consequences are discussed.

Clinical Trials as Topic↗
PubMed1987

Airways obstruction and the risk for lung cancer.

The presence of airways obstruction identify in middle-aged male smokers at increased risk for lung cancer. This hypothesis was tested in a sample of patients with moderate to severe obstruction from the Intermittent Positive Pressure Breathing Trial and a sample of patients with no obstruction to moderate obstruction from the Johns Hopkins Lung Project, all of whom were followed for the development of lung cancer. On follow-up, the risk of developing lung cancer was found to be associated with entry values for age, smoking, and ventilatory status by linear, proportional hazard, and log-linear adjustment techniques. Among cigarette smokers, the presence of airways obstruction was more of an indicator for the subsequent development of lung cancer than was age or the level of smoking. The risk for lung cancer also increased in proportion to the degree of airways obstruction. These data suggest that smokers with ventilatory obstruction are at greater risk for lung cancer than are smokers without obstruction.

Age Factors↗
PubMed1986

Prognosis in chronic obstructive pulmonary disease.

We recruited 985 patients with COPD but without hypoxemia or other serious disease, treated them in a standard fashion, and followed them closely for nearly 3 yr. At the time of recruitment the patients were carefully characterized as to symptom severity, lung function, exercise tolerance, and quality of life, and studies of lung function were repeated during follow-up. Overall mortality was 23% in 3 yr of follow-up. Patient age and the initial value of the FEV1 were the most accurate predictors of death; when FEV1 before bronchodilator was used, the response to bronchodilators was directly related to survival, but this relationship became nonsignificant when postbronchodilator FEV1 was used as a primary predictor. After adjustment for age and FEV1, mortality was related positively to TLC, resting heart rate, and perceived physical disability, and related negatively to exercise tolerance. These relationships, though significant, were relatively weak. When standardized for age and FEV1, mortality in the present series was less than that of a previous series (4), and the same as that of hypoxemic patients with COPD who received continuous home O2 therapy. Changes in FEV1 with time averaged -44 ml/yr, but the standard deviation was large. Patients with low initial values of FEV1 showed relatively little further decline, probably indicating a survivor effect. In patients with well-preserved initial FEV1, rate of decline correlated negatively with bronchodilator response, symptomatic wheezing, and psychological disturbances.

Adult↗
PubMed1986

Bronchodilator response in chronic obstructive pulmonary disease.

We measured response to 250 micrograms isoproterenol in 985 patients with COPD who were carefully studied and followed closely for nearly 3 yr. Response was quantitated in relative (% increase in FEV1) and absolute (change in FEV1 as a % predicted normal) terms. Patients were told to abstain from bronchodilator for 6 h before testing, and responses were larger in those who said they had done this. Responses were not related to blood theophylline concentrations. In patients who had abstained for 6 h, response averaged 15% of the baseline FEV1 or 5% of the predicted normal FEV1. Relative response was inversely proportional to baseline FEV1, whereas absolute response was directly related to baseline FEV1. Responses were positively related to symptomatic wheezing and exercise capacity, and negatively to smoking history, but these features accounted for little of the observed variation in response. Patients with large relative and absolute responses demonstrated increased variability of FEV1 with time and a decreased annual rate of decline of FEV1. There was little change in response with time, and the change observed could probably be explained by a gradual decrease in FEV1. However, time-related interindividual and intraindividual variations of response were large and impossible to separate from random variations of FEV1.

Adult↗
PubMed1985

Influence of genes of the major histocompatibility complex on ulcerative dermal necrosis induced in mice by Mycoplasma arthritidis.

All mouse strains injected s.c. with Mycoplasma arthritidis developed severe abscesses in the subdermal tissues. However, M. arthritidis strain 14124 P10 also induced an ulcerative dermal coagulation necrosis in mouse strains expressing the k and d haplotypes but not in those expressing the b, q, or s haplotypes. The use of inbred and congenic mouse strains established that the ulcerative necrosis was associated with the haplotypes expressed at the H2 major histocompatibility complex (MHC). The gene restriction seen could be partially overcome by using a more virulent mouse-passaged strain of M. arthritidis (158 P10P9). The data suggest that genes of the MHC function by rendering certain mouse strains more susceptible to an as yet unidentified necrotizing moiety. The close histologic resemblance of the dermal necrosis induced by M. arthritidis to certain human diseases such as necrotizing fasciitis, the ulcerative lesions induced by Mycobacterium ulcerans, and the crepitant and gangrenous cellulitides may therefore provide a unique model to study the genetic factors and mechanisms of pathogenesis in these latter human conditions.

Animals↗
PubMed1985

Xylose absorption in Down's syndrome.

A standard xylose absorption test was carried out in 14 people with Down's syndrome (DS) and in 14 age-matched mentally deficient controls; a further 30 people with DS were similarly investigated. Mentally deficient people as a group were found to have impaired xylose absorption, the matched DS subjects having a significantly reduced xylose absorption (P less than 0.001) when compared to the mentally deficient controls. Ninety percent of the DS subjects had a xylose excretion below the normal range. At present it is not possible to identify the cause of the malabsorption but it is highly likely that the malabsorption plays a role in a number of the vitamin and mineral deficiencies found in people with DS.

Adult↗
PubMed1984

Quality of life and its predictors in patients with mild hypoxemia and chronic obstructive pulmonary disease.

Measures of quality of life were obtained on 985 patients with mild hypoxemia and chronic obstructive pulmonary disease (COPD). A subsample of 100 patients were also given extensive neuropsychological and personality tests. Mildly hypoxemic COPD patients showed impairment in quality-of-life activities. They showed less impairment in physical function, compared with previous studies on COPD patients with hypoxemia, but about equal impairment in psychosocial function and dysphoric mood. Nonrelated health changes in life do not seem to account for these findings. Degree of self-reported tension-anxiety was the single greatest predictor of both physical and psychosocial measures of quality of life. Level of exercise completed, forced expiratory volume in 1 s, and neuropsychological status were significantly related to physical limitations, but not psychosocial functioning. The Pao2 was not significantly related to quality-of-life measures in this patient group.

Adult↗
PubMed1983

Primary pulmonary artery sarcoma diagnosed noninvasively by two-dimensional echocardiography.

A 21-year-old white male was evaluated in our echocardiographic laboratory for presumed mitral valvular bacterial endocarditis. Electrocardiographic, physical, and initial two-dimensional echocardiographic findings suggested a left-to-right shunt at the atrial septal level. However, injection of contrast saline solution failed to demonstrate signs of an atrial septal defect. Continuation of the echocardiographic study led to the diagnosis of an unsuspected primary sarcoma of the pulmonary trunk, which was rapidly confirmed by computerized axial tomography. Therapeutic interventions were undertaken. This case highlights the usefulness of two-dimensional echocardiography.

Adult↗
PubMed1980

Enzymatic control of phenylalanine intake in phenylketonuria.

The plant enzyme phenylalanine ammonia lyase (PAL) will survive in the gut for long enough to deplete the phenylalanine derived from food protein and so reduce the rise in blood phenylalanine that otherwise occurs after a protein meal. This effect has been demonstrated in healthy adults and phenylketonuric (PKU) patients. When the enzyme was given to an untreated PKU patient for 12 consecutive days (three doses a day after food) his blood phenylalanine levels were reduced on average by a quarter. This enzyme preparation may have a place in the treatment of PKU.

Adult↗
PubMed1980

Glutathionuria: gamma-glutamyl transpeptidase deficiency.

A mentally retarded young woman with severe behaviour problems was found to excrete large amounts of glutathione due to a generalized gamma-glutamyl transpeptidase deficiency. As in the only other case described in detail, plasma levels and renal reabsorption of the amino acids were normal. In the parents' urine, plasma and leukocytes, enzyme activity was normal but in their cultured fibroblasts it was below the minimum for the control range. An autosomal recessive mode of inheritance is suggested. The implications of these findings for possible role of the gamma-glutamyl cycle in amino acid transport are briefly discussed.

Adult↗
PubMed1979

Passive-active immunity from hepatitis B immune globulin. Reanalysis of a Veterans Administration cooperative study of needle-stick hepatitis. The Veterans Administration Cooperative Study Group.

The mechanism of action of hepatitis B immune globulin (HBIG) and immune serum globulin was sought in a reanalysis of a Veterans Administration cooperative study on needle-stick exposure to hepatitis B surface antigen (HBsAg)-positive blood. Sera from 296 exposed persons were tested for HBsAg, antibody to HBsAg (anti-HBs), and antibody to hepatitis B core antigen (anti-HBc) by radioimmunoassay. Type B hepatitis developed in three HBIG (2%) and in 12 ISG (8%) recipients. In contrast, subclinical infection (development of HBsAg or anti-HBs and anti-HBc without symptoms or jaundice) developed in 16 HBIG (10%) but only six immune serum globulin (4%) recipients. Thus, infection occurred equally in both groups but was more likely to be subclinical in HBIG recipients, indicating that HBIG permitted development of passive-active immunity to type B hepatitis. An additional 53 immune serum globulin recipients (36%) but only one HBIG recipient developed anti-HBs alone, without hepatitis, HBsAg, or anti-HBc. This response was more compatible with immunization by HBsAg than with infection. Ultracentrifugation analysis revealed occult HBsAg in the immune serum globulin but not the HBIG, indicating that some immune serum globulin preparations contain HBsAg and can induce active immunity to type B hepatitis.

Hepatitis B↗
PubMed1978

Type B hepatitis after needle-stick exposure: prevention with hepatitis B immune globulin. Final report of the Veterans Administration Cooperative Study.

Hepatitis B immune globulin (HBIG) and immune serum globulin (ISG) were examined in a randomized, double-blind trial to assess their relative efficacies in preventing type B hepatitis after needle-stick exposure to hepatitis B surface antigen (HBsAG)-positive donors. Clinical hepatitis developed in 1.4% of HBIG and in 5.9% of ISG recipients (P = 0.016), and seroconversion (anti-HBs) occurred in 5.6% and 20.7% of them respectively (P less than 0.001). Mild and transient side-effects were noted in 3.0% of ISG and in 3.2% of HBIG recipients. Available donor sera were examined for DNA polymerase (DNAP) and e antigen and antibody (HBeAg; anti-HBE). Both DNAP and HBeAg showed a highly statistically significant correlation with the infectivity of HBsAg-positive donors. Hepatitis B immune globulin remained significantly superior to ISG in preventing type B hepatitis even when the analysis was confined to these two high-risk subgroups. The efficacy of ISG in preventing type B hepatitis cannot be ascertained because a true placebo group was not included.

Adolescent↗
PubMed1977

A randomized, double blind controlled trial of the efficacy of immune serum globulin for the prevention of post-transfusion hepatitis. A Veterans Administration cooperative study.

A double blind, randomized, controlled trial has been conducted in 11 Veterans Administration hospitals during a 49-month period to compare the relative efficacies of immune serum globulin (ISG) and an albumin placebo for the prevention of post-transfusion hepatitis (PTH). A total of 2204 patients, of whom 1094 received ISG, participated in the study. The results indicate that ISG significantly reduced the incidence of icteric type non-B hepatitis only (inferred to be also type non-A hepatitis). Adverse reactions were rare, and the ISG did not significantly alter the incubation period or duration of the disease. The data suggest, however, that a similar reduction in type non-A, non-B hepatitis would have occurred had commercial blood been excluded from use. Analysis of the 241 patients who developed hepatitis indicates that type B hepatitis constituted less than 20% of the cases each year of the study. Furthermore, the efficacy of the ISG, manufactured in 1944, against apparent type non-A, non-B hepatitis suggests that this overlooked disease has existed from at least that time. Host- and transfusion-related factors that might have modified the development of PTH were examined. The use of commercial blood was observed to be the most important risk factor. It is concluded that the PTH incidence can be most effectively reduced by eliminating commercial donor blood, and continuing to screen volunteer donors for hepatitis B surface antigen (HBsAg) by sensitive procedures. Of prime importance is the need to define the agent(s) responsible for type non-A, non-B hepatitis.

Adult↗
PubMed1976

Type B hepatitis: the infectivity of blood positive for e antigen and DNA polymerase after accidental needlestick exposure.

To determine the relation between the presence of donor DNA polymerase and e antigen, and recipient hepatitis, we tested, under code, serums from a controlled trial of hepatitis B immune globulin used to treat individuals accidentally inoculated with HBs Ag-positive blood. All recipients lacked antibody to HBs Ag. In 29 of 31 donors, both polymerase and e were in perfect agreement; both demonstrated a highly significant correlation with recipient hepatitis (P less than 0.001). DNA polymerase/e-negative blood did not cause hepatitis. Blood containing polymerase or e antigen did not cause hepatitis in six of 31 and four of 18 recipients, respectively. Hepatitis did not correlate with transaminase or duration of antigenemia in the donor. Polymerase and e appear to be indicators of the relative infectivity of HBs Ag-positive serum, particularly after small-volume exposure. They may be important determinants in assessing infectivity of chronic carriers of HBs Ag and in evaluating efficacy of hepatitis B immune globulin and hepatitis B vaccines.

Acute Disease↗