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Biomedical subjects

C Lewis

Publications and source records attributed to C Lewis.

At least 127 records · Page 7Linked to original sources
PubMed1996

Reliability and changes in validity of self-reported cardiovascular disease risk factors using dual response: the behavioral risk factor survey.

The authors previously studied the validity of self-reported cardiovascular disease (CVD) risk factors assessed by telephone surveys, and found the validity low, especially for self-reported hypertension and hypercholesterolemia. One way to improve validity is to combine repeated measurements (dual response) into a single measure. The authors explored this and the reliability of self-reported CVD data collected by the Behavioral Risk Factor Survey in three New York counties from January 1989 to May 1990. Nine hundred and eleven subjects were interviewed by telephone to collect CVD risk factor and health behavior information. Interviewees were offered physical examination and laboratory testing to verify self-reported CVD risk factors; 628 participated. Subjects were also reinterviewed to assess the test-retest reliability of the survey, and to study how validity of self-reported CVD data changes by dual response. Reliability coefficients for CVD risk factors, preventive health practices, and knowledge of risk factor levels ranged from 0.42 to 0.99. Minimal improvement in sensitivity of self-reported risk factors was found using dual response, and it did not improve specificity. Also, for prevalence of risk factors, dual response minimally improved self-reported rates compared to objective estimates. Combining self-reported measurements causes minimal changes in the validity of these variables. Physiological assessment for hypertension and hypercholesterolemia, or correction for misclassification, is needed for valid individual measurement and for community prevalence estimates from telephone surveys. Self-reported cigarette smoking, obesity, and diabetes mellitus have better validity, but physiological assessment or correction for misclassification may supplement these self-reported risk factors.

Adult↗
PubMed1996

Implantation of multiple foldable acrylic posterior chamber lenses in the capsular bag for high hyperopia.

This case series describes the implantation of multiple acrylic intraocular lenses (IOLs) in the capsular bag of six eyes of three highly hyperopic patients (spherical equivalent +5.75 to +8.62) during cataract surgery. Two foldable acrylic lenses were placed in the capsular bag of each eye. Preoperative best corrected visual acuity (BCVA) ranged from 20/50 to 20/300. Postoperative uncorrected visual acuity ranged from 20/25 to 20/60, while BCVA ranged from 20/25 to 20/40. Multiple acrylic lenses were used successfully in cases in which a single IOL would have given inadequate correction.

Acrylates↗
PubMed1996

Phase I/II trial of filgrastim (r-metHuG-CSF), CEOP chemotherapy and antiretroviral therapy in HIV-related non-Hodgkin's lymphoma.

BACKGROUND: A phase I/II trial determined the maximum tolerated dose (MTD) of CEOP for AIDS-related non-Hodgkin's lymphoma (NHL) with concurrent filgrastim and antiretroviral therapy. PATIENTS AND METHODS: Fourteen AIDS-NHL patients, chemotherapy naïve and ECOG performance status < 2 received filgrastim 1.0 microgram/kg s.c. daily for 3-7 days to assess neutrophil response, followed by CEOP with filgrastim support 10 micrograms/kg s.c. daily, day 2-14, continued if the absolute neutrophil count (ANC) < 1.2 x 10(9)/l. Two CEOP dose cohorts were used: cohort 1 (5 patients) - cyclophosphamide (C) 500 mg/m2, epirubicin (E) 37.5 mg/m2, vincristine (O) 2 mg and prednisolone (P) 75 mg/m2 daily on days 1-5; cohort 2 (9 patients) - C 750 mg/m2, E 50 mg/m2, same doses of O and P. Antiretroviral therapy was maintained (zidovudine-10, ddI-3, both-1). RESULTS: In cohort 1, 4/5 patients received at least 3 courses of CEOP with one complete response after five cycles and four progressions. Four have died (3-21 months after entry) with 1 alive at 40 months. Dose limiting toxicity (DLT - grade IV febrile neutropenia in cycle 1) occurred in 1 patient. In cohort 2, 5/9 completed > or = 5 cycles with 6 complete responses, 1 partial response and 2 progressions, 6 deaths and 3 alive at > 33 months. DLT (evaluable in 8 patients) occurred in two patients. Median survival for both cohorts was 17 months. Mean relative dose intensity was > 85%. CONCLUSIONS: The dosages of CEOP in cohort 1 defined the MTD however, the cohort 2 doses with filgrastim and antiretroviral therapy gave an encouraging response, acceptable toxicities and merit further study.

Adult↗
PubMed1996

The effect of a medical school's admission and curriculum policies on increasing the number of physicians in primary care specialties.

PURPOSE: The Charles R. Drew University of Medicine and Science, which is affiliated with the University of California, Los Angeles, UCLA School of Medicine, has a mission to increase the number of physicians pursuing careers in primary care and/or providing care to the underserved. The authors sought to determine whether Drew's initial classes are pursuing career paths consistent with the institution's mission. METHOD: In June 1992 the alumni from the Drew and UCLA classes of 1985 through 1987 were mailed questionnaires to ascertain their specialty choices and practice settings. Responses were analyzed using bivariate analyses and multiple logistic regression. RESULTS: The response rates were 89% (402 of 454) for the UCLA graduates and 76% (44 of 58) for the Drew graduates. Bivariate analyses showed that Hispanics, women, older individuals, and Drew graduates were more likely to choose primary care specialties (p < .001 for each variable). Multiple logistic regression also showed that these variables predicted primary care career choice: for being a Hispanic, odds ratio (OR) = 3.2, 95% CI (1.66, 6.35); for being a woman, OR = 1.9, 95% CI (1.28, 2.97); for being older, OR = .92, 95% CI (.86, .99); and for being a Drew graduate, OR = 2.4, 95% CI (1.09, 5.27). Older graduates practiced in underserved areas more than did younger ones (26% vs 13%, p = .03). CONCLUSION: To some degree, Drew has fulfilled its mission of graduating physicians who are primary care specialists and/or practice in underserved areas; however, the results raise questions regarding possible early influences on career choice.

Adult↗
PubMed1996

Evaluation in the Substance Abuse and Mental Health Services Administration.

The evaluation policy of the Substance Abuse and Mental Health Services Administration (SAMHSA) is described in this article. Three studies are presented that exemplify SAMHSA's evaluations. These include evaluations of a program to prevent substance abuse among pregnant and postpartum women and their infants; a Job Corps treatment enrichment program; and the McKinney program for homeless persons with severe mental illnesses. Each of these evaluations demonstrated the effectiveness of the programs in reducing substance abuse or homelessness and in improving the health and well-being of the consumers served. SAMHSA will use the results of these and similar evaluations to guide policy and program development. Through its evaluations, SAMHSA must identify effective approaches to prevention, treatment, and rehabilitation. By using its evaluation results to guide policy and program development, SAMHSA aims to improve the quality of the public system of substance abuse and mental health services.

Adolescent↗
PubMed1996

Local government reorganisation in Scotland and Wales.

This article describes the new local authority structure that comes into effect in Scotland and Wales on 1 April 1996. The relationship between the new 'unitary' authorities and other administrative areas is discussed briefly and some key demographic data are presented. References are given to other sources of statistical information.

Adolescent↗
PubMed1996

Is general practice audit alive and well? The view from Portsmouth.

A brief look at medical audit activity in the Portsmouth and South East Hampshire Health Authority area by use of a questionnaire mailed out to general practitioners, information from the medical audit advisory group database and the local health authority records. The details collected consisted of topics chosen, the stage of audit cycle reached, funding arrangements, practice personnel and the outside collaborators involved. Most general practices were found to be undertaking audit activity, and in some it had become integrated into the everyday routine.

England↗
PubMed1996

Social influences on false belief access: specific sibling influences or general apprenticeship?

Some recent studies have found a relation between the number of siblings 3-4-year-old children have and their performance on false belief tasks. 2 experiments reported here examine a variety of factors in children's social environments, including daily contact with peers and adults as well as the numbers of their siblings, on a battery of false belief tests. In Experiment 1, 82 preschoolers were studied in Rethymnon, Crete, in order to obtain a range of extended kin available as a resource for the child. In Experiment 2, 75 Cypriot preschoolers were studied in Nicosia in order to examine the influences of each child's daily social contacts, as measured by maternal questionnaire. Logistic regression revealed that the factors which account for most of the predicted variance on the theory of mind tests were (a) the number of adult kin available (Experiment 1) or adults interacted with daily (Experiment 2), (b) the child's age, (c) the number of older siblings a child has, and (d) the number of older children interacted with daily. The results suggested that theory of mind is not simply passed from one sibling to another in a process of social influence. It seems more likely that a variety of knowledgeable members of her or his culture influence the apprentice theoretician of mind.

Age Factors↗
PubMed1995

Coexpression of P2X2 and P2X3 receptor subunits can account for ATP-gated currents in sensory neurons.

Cation-selective P2X receptor channels were first described in sensory neurons where they are important for primary afferent neurotransmission and nociception. Here we report the cloning of a complementary DNA (P2X3) from rat dorsal root ganglia that had properties dissimilar to those of sensory neurons. We also found RNA for (P2X1)(ref. 7), (P2X2)(ref. 8) and P2X4 (ref. 9) in sensory neurons; channels expressed from individual cDNAs did not reproduce those of sensory ganglia. Coexpression of P2X3 with P2X2, but not other combinations, yielded ATP-activated currents that closely resembled those in sensory neurons. These properties could not be accounted for by addition of the two sets of channels, indicating that a new channel had formed by subunit heteropolymerization. Although in some tissues responses to ATP can be accounted for by homomeric channels, our results indicate that ATP-gated channels of sensory neurons may form by a specific heteropolymerization of P2X receptor subunits.

Adenosine Triphosphate↗
PubMed1995

The phosphorylation state of the microtubule-associated protein tau as affected by glutamate, colchicine and beta-amyloid in primary rat cortical neuronal cultures.

The effects of the excitatory amino acid glutamate, the microtubule destabilizing agent colchicine, and beta 25-35-amyloid peptide on the phosphorylation state of tau were studied in rat cortical neurons in primary culture. Using immunocytochemistry and Western-blot analysis, we demonstrated that a proportion of tau in these cultures is normally highly phosphorylated, but most of this tau fraction is dephosphorylated after treatment of the cultures with glutamate or colchicine, but not with beta-amyloid; the glutamate- and colchicine-induced changes in tau phosphorylation commenced before cell death, as assessed by release of lactate dehydrogenase. Dephosphorylation of tau was readily revealed by using the monoclonal antibodies Tau.1 and AT8, which have phosphate-sensitive epitopes that both centre around serine-199 and -202 (numbering of the largest tau isoform). On Western blots and by immunocytochemistry, AT8 labelling strongly decreased after glutamate and colchicine treatments, whereas Tau.1 staining was more intense. Neurofilament monoclonal antibodies, including RT97, 8D8, SMI31 and SMI310, all additionally known to recognize tau in a phosphorylation-dependent manner, also demonstrated that glutamate and colchicine treatments of the cultures induced a dephosphorylation of tau. We also showed immunocytochemically that there is an increase in tau immunoreactivity in neuronal perikarya in response to glutamate and colchicine treatment, and this occurs concomitantly with the dephosphorylation of tau. Treatment of the primary rat cortical neuronal cultures with beta 25-35-amyloid peptide, under conditions which induce neuronal degeneration, did not induce a change in tau phosphorylation, and failed to act synergistically with glutamate to produce an increase in dephosphorylation of tau over that produced by glutamate treatment alone. These findings demonstrate that glutamate and colchicine induce tau dephosphorylation, as opposed to increased tau phosphorylation, which would be more indicative of Alzheimer-type neurodegeneration.

Amyloid beta-Peptides↗
PubMed1995

Estrogen-induction of dendritic spines in ventromedial hypothalamus and hippocampus: effects of neonatal aromatase blockade and adult GDX.

Treatment of male rats at birth with an aromatase inhibitor (Letrazole), followed by adult gonadectomy GDX, led to an increase in dendritic spine density on ventromedial hypothalamic neurons (VMN) when treated with estrogen as compared to a decrease when vehicle animals were given estrogen. In contrast, estrogen-treatment increased dendritic spine density on CA1 pyramidal neurons regardless of neonatal treatment. In addition, in CA1 there was a significant difference between the two estrogen groups. These results suggest that estrogen induction of dendritic spines in the VMN and CA1 is dependent on organizational effects of gonadal steroids.

Animals↗
PubMed1995

Role of mycotoxins in human and animal nutrition and health.

The impact of mycotoxins on human and animal health is now increasingly recognised. Mycotoxin entry to the human and animal dietary systems is mainly by ingestion but increasing evidence also points at entry by inhalation. Mycotoxins exhibit a wide array of biological effects and individual mycotoxins can be mutagenic, carcinogenic, embryotoxic, teratogenic, or oestrogenic. Average levels of ingestion of currently known mycotoxins in most EEC countries are rather low. Little is known about the consequences to humans of such mycotoxin intakes. Establishing a causal relationship between mycotoxin exposure and human disease is complicated by uncertainties associated with human epidemiological studies. Analysis of mycotoxin adducts in human populations can act as a surrogate for human genotoxicity. Mycotoxins can also be immunosuppressive and appear to involve cellular immune phenomena and non-specific humoral factors associated with immunity.

Animals↗
PubMed1995

Laparoscopic abdominoperineal excision of the rectum.

In laparoscopic abdominoperineal resection of the rectum (LAP-AP) an abdominal incision is completely avoided as the tumor is delivered through the perineal incision. It is our belief that the view provided in the pelvis by laparoscopy is significantly better than at laparotomy and allows excellent anatomical definition and meticulous dissection. In this study we compared the adequacy of excision of the first 12 patients undergoing LAP-AP to the last 16 patients undergoing open abdominoperineal resection (OP-AP). In all patients the procedure was carried with curative intent for adenocarcinoma and the Dukes staging and Jass score's were similar in both groups. [table: see text] The data demonstrate similar nodal harvest in both groups as well as extent of radial excision. However, two patients in the open group had microscopic radial margin involvement despite being microscopically clear at surgery. We conclude that although long-term follow-up is required to address the issue of local cancer recurrence, laparoscopic rectal dissection appears as good as open surgery and may allow a more precise assessment of excision margins.

Adult↗
PubMed1995

"Is this man your daddy?" suggestibility in children's eyewitness identification of a family member.

Studies of natural language development suggest that overextension of family memberships terms, such as daddy or papa, occurs in children in the second year of life, but rarely persists thereafter. However, in British Courts it is common for the testimony of 3- and even 4-year-olds to be dismissed on the grounds that these children may not be reliably identifying their father or stepfather when they claim that daddy was the perpetrator of abuse. This study examined whether 3-year-olds could be persuaded to confirm that a stranger who was labelled as daddy was their own father. A mock interview with experienced disclosure interviewers was conducted. Five of the 17 children--all from blue-collar families--misidentified a photograph of their own father when an identification question was repeated. Rather than undermining the validity of all preschoolers testimony, it is suggested that the responses of some children to apparently mundane questions of fact are influenced by contextual factors, including repetition of the question and the perceived omniscience of the interviewer.

Child Abuse↗