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Biomedical subjects

C Lewis

Publications and source records attributed to C Lewis.

At least 163 records · Page 9Linked to original sources
PubMed1994

The prevalence of specific arithmetic difficulties and specific reading difficulties in 9- to 10-year-old boys and girls.

Data from an epidemiological sample (n = 1206) of British schoolchildren were used to estimate the proportions of 9- to 10-year-olds with specific arithmetic difficulties (SAD), combined with arithmetic-and-reading difficulties (ARD), and specific reading difficulties (SRD). Children in the sample contributed scores on separate tests of arithmetic, reading and nonverbal intelligence. Using a cutting-score approach, which took into account performance on all three tests, a small group of children with SAD (1.3%) were distinguished from larger groups with ARD (2.3%) and SRD (3.9%). Contrary to some previous reports, there were equal numbers of males and females within each of the two groups with arithmetic difficulties but a preponderance of males over females amongst the group with specific reading difficulties.

Child↗
PubMed1994

A speech rate measure of laboratory induced affect: the role of demand characteristics revisited.

The study examined the effects of mood shift on a behavioural measure to investigate an ongoing question in the mood induction literature: Whether changes in performance following laboratory based mood induction procedures reflect genuine changes in affective state, or whether such changes can be generally attributed to the demand characteristics of the experimental situation. Prior to mood induction 40 subjects were assessed on self-spaced and maximal performance articulation tasks. Following mood induction articulation rates were again recorded. It was hypothesized that while there is considerable scope for experimental demands to influence self-paced tasks, by contrast maximal performance tasks should either reduce or eliminate demand characteristics. The results indicated that maximal articulation rate was sensitive to mood induction in that performance was retarded by the depressogenic procedure and accelerated by the elation-inducing procedure. Additionally, within-subject changes in speech rates correlated with conventional self-report measures of affective state. Interestingly, the speeded task appeared more sensitive to the mood manipulation than the self-paced task where demand characteristics had been expected to exert their greatest effect. It is concluded that these results corroborate the view that laboratory based induction procedures do promote true affective change and indicate that the speeded articulation task constitutes an effective indicator of that change.

Adult↗
PubMed1994

A review of the use of chemoprotectants in cancer chemotherapy.

Dose-limiting toxicity secondary to antineoplastic chemotherapy is principally due to the inability of the drugs to differentiate between normal and malignant cells. This results in normal tissue damage, as well as the desired antitumour effect. Toxicity may be acute, as in cisplatin-induced nephrotoxicity or alkylating agent myelotoxicity and haemorrhagic cystitis, or cumulative, as in anthracycline-related cardiac toxicity or cisplatin neurotoxicity. The consequences of this often include serious adverse effects and the inability to deliver adequate dose-intensive therapy against the cancer. Chemoprotective agents have been developed to provide site-specific protection against normal tissue toxicity, without compromising antitumour activity. Several chemoprotective compounds have recently been developed, including dexrazoxane (ICRF-187), amifostine (ethiofos: WR-2721), mesna and ORG-2766. Initial results confirm their promise as selective protective agents, although further randomised trials are required to identify their optimal role when used alone or in combination with other toxicity modifiers, including haematopoietic growth factors, with the ultimate aim being adequate dose escalation of chemotherapy to overcome tumour resistance.

Adrenocorticotropic Hormone↗
PubMed1994

Skewed T-cell receptor usage and junctional heterogeneity among isletitis alpha beta and gamma delta T-cells in human IDDM [corrected].

Because of anatomical limitations, molecular characterization of islet-inflammatory T-cells in human insulin-dependent diabetes mellitus (IDDM) has remained elusive. We have isolated isletitis T-cells from pancreas graft biopsies of two patients (syngeneic and allogeneic, respectively) shortly after onset of recurrent IDDM and have characterized their repertoire by sequencing T-cell receptor (TcR)-specific cDNAs. Histopathological analysis of the grafts revealed selective beta-cell loss and isletitis characteristic of recurrent disease with no evidence of chronic inflammation or rejection. Most of the in vivo-activated isletitis T-cells were CD8+TcR alpha beta+ and CD4-CD8-TcR gamma delta+ in both patients. Comparison of the different TcR alpha,beta,gamma, and delta sequences revealed V(D)J junctional heterogeneity but skewed TcR usage within patients. Eighth of 13 different isletitis TcR beta sequences (19 of 26 cDNAs) from the syngeneic graft of patient 1 were V beta 3+, as opposed to only 1 of 31 peripheral TcR beta sequences (1 of 31 cDNAs) (61.5 vs. 3.2%, P < 0.0001). Of the 19 different isletitis TcR alpha clonotypes of this patient (24 of 42 cDNAs), 5 were V alpha 14+. The isletitis TcR beta clonotypes of the human leukocyte antigen-identical allogeneic graft of patient 2 showed selective J beta, but not V beta, gene usage. Two of three predominant isletitis clonotypes of patient 2 were V alpha 22+ (19 of 28 cDNAs) and the other (5 of 28 cDNAs) was also V alpha 14+.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The Governance Symposium--Part II. A new context for trustees.

Today you are a hospital trustee. If health care reform doesn't scare you away, tomorrow you could be governing a system, a network, a physician/hospital organization, or a community hospital that belongs to one of these other entities. managed care will change your priorities, your responsibilities, and the expectations others have of you as well as the health care delivery system. To learn more about the trustee's role in a reformed health care system, the American Hospital Association and Trustee recently convened a governance symposium (see the list of participants on the opposite page). The first part of the discussion from that symposium was presented in the August issue (see "Quantum leap," page 6). The second part focuses on the issues of board accountability and compensation and realigning incentives for the future.

Governing Board↗
PubMed1994

Assessment of general practitioners' management of hyperlipidaemia. A study using personal visits and a scenario-based questionnaire.

In summary our study has looked at the current management practices of hyperlipidaemia by general practitioners in an innovative way. Our results suggest that most GPs are managing this condition appropriately. Where their management differs from current guidelines is mainly in introducing medication early. We obtained significantly lower participation rates in the metropolitan as compared with the regional and rural areas, but we found no significant differences in the overall assessment of appropriate management between the different geographical regions of Victoria.

Data Collection↗
PubMed1994

Evaluation of two AIDS education programs for impoverished Latina women.

This paper evaluates and contrasts the effectiveness of two culturally sensitive AIDS education programs developed by the UCLA AIDS Nursing Network and delivered to 213 impoverished Latina homeless or drug-addicted women in Los Angeles. The Comprehensive Health Seeking and Coping Paradigm guided the program, which was implemented by specially trained Latina nurses and outreach workers. A quasi-experimental design was employed where women were randomized by site into Specialized (N = 82) and Traditional (N = 131) programs. Repeated measures ANOVAS and log-linear models were used to evaluate improvement over a two-week period for women in both groups and to identify interactions with program type. Two-week posttest analyses were also conducted to assess program effectiveness, controlling for baseline values of the measure in question, nonequivalency between groups at baseline, and selected demographic characteristics, including acculturation. Results indicated that women in both AIDS education programs improved significantly in cognitive, behavioral, and psychologic outcomes.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Access to prenatal care following major Medicaid eligibility expansions.

OBJECTIVE: To determine whether lack of financial access was a significant barrier to prenatal care following major expansions of Medicaid eligibility in California. DESIGN: Retrospective analysis of birth certificates, assessing risks of inadequate prenatal care by insurance, controlling for maternal race/ethnicity, birthplace, age, parity, education, and marital status. SAMPLE: Singleton live births to California residents occurring in-state in 1990 (N = 593,510). OUTCOME MEASURES: Untimely initiation of care, two few visits, and no prenatal care. RESULTS: Despite major Medicaid expansions, nearly 11% of live births were uninsured for prenatal care. Being uninsured and having Medi-Cal were both risk factors of sizable magnitude, controlling for maternal characteristics. Compared with women who had private fee-for-service coverage, uninsured women were at elevated risk of untimely initiation (odds ratio [OR], 2.54; 95% confidence interval [CI], 2.47 to 2.60) and too few visits (OR, 2.49; 95% CI, 2.44 to 2.55). Women with Medi-Cal had a high risk of untimely care (OR, 3.33; 95% CI, 3.26 to 3.40); their risk of too few visits was also elevated (OR, 1.63; 95% CI, 1.60 to 1.66) but less than for the uninsured. Lack of private insurance was a strong risk factor for no care (OR, 6.70; 95% CI, 6.00 to 7.47). CONCLUSIONS: In spite of major Medicaid expansions, access to prenatal care was limited for women without private insurance. Medicaid was associated with untimely entry but with improved continuity. The findings suggest that financial barriers were salient even when controlling for many factors related to care-seeking behavior. Policy initiatives need to address continuing financial barriers along with other obstacles.

Adolescent↗
PubMed1993

Differences in the requirement of antigen-presenting cells for long-term growth among cytomegalovirus-specific Th clonotypes.

Functional and molecular studies of in vivo-activated T lymphocytes involved in normal and abnormal immune responses, i.e., cells infiltrating tissues affected by autoimmune processes, require their previous in vitro expansion. Problems such as unavailability of specific antigen(s) (Ag) and/or the requirement of large amounts of autologous peripheral blood mononuclear cells (PBMC) as feeders have prompted the development of alternative expansion methods that circumvent the use of antigen-presenting cells (APC) and/or Ag. We have previously shown that cytomegalovirus (CMV)-specific T cell lines and clones can be efficiently propagated in long-term cultures by stimulation with agonistic monoclonal antibodies (mAb) coated onto polystyrene particles in the absence of APC. However, this and other stimulation protocols may skew the repertoire of clonotypes that proliferate in response to nominal Ag and APC. Here we show that polyclonal populations of CMV-primed and interleukin-2 (IL-2)-stimulated PBMC undergo the same clonotypic selection when induced to grow both by continuous stimulation with CMV and an anti-CD3 mAb presented by APC. This selection, reproduced in three independent expansion experiments, involved the dominant growth of two CMV-specific, IL-2-secreting CD4+ clonotypes sharing J alpha, J beta, V alpha and V beta genes and highly homologous T cell receptor (TcR) junctional sequences. The dominant growth of these 2 clonotypes required a direct T cell/APC interaction since when coated onto polystyrene particles the same mAb induced the selective expansion of another IL-2-secreting CD4+ CMV-specific clonotype expressing a different, yet homologous, TcR heterodimer (used same V alpha and V beta genes), which was underrepresented before expansion (5 vs. 58%). T cell clones belonging to the subdominant clonotype proliferated significantly faster in response to stimulation with anti-CD3 mAb coated onto beads than in response to stimulation with CMV or anti-CD3 mAb presented by APC, possibly due to long-term expansion without APC or antigen. In contrast, neither the dominant clonotypes nor unprimed T cells were able to undergo CD3-mediated expansion in the absence of APC. We conclude that quantitative differences in growth competency among normal Ag-activated T-helper (Th) clonotypes in response to antigenic stimulation can be reproduced by stimulation through the TcR in the absence of TcR occupancy but only in the presence of APC and that certain clonotypes do not require APC for long-term growth in vitro. These data have practical implications for the isolation and repertoire characterization of in vivo-activated T cells from tissues affected by inflammatory, i.e. autoimmune, phenomena.

Amino Acid Sequence↗
PubMed1993

Outcomes of specialized and traditional AIDS counseling programs for impoverished women of color.

The efficacy and differential effects of specialized (S) and traditional (T) AIDS education programs on cognitive, behavioral, and psychological outcomes were investigated. The sample consisted of 858 impoverished African-American and Latina women (S = 448, T = 410). At baseline, women in the traditional group reported significantly higher distress, greater knowledge of AIDS, and less problem-focused coping. Significant improvements over the 2-week intervention interval were found for participants of both AIDS education programs for appraisal of threat, concerns, knowledge, and attitudes about AIDS, emotion-focused coping, number of sexual partners, IV and non-IV drug use, depression, and distress. However, multivariate analysis indicated that the traditional group had slightly better posttest scores on concerns, emotion-focused coping, knowledge of AIDS, and number of partners than the specialized group. The specialized group reported greater use of problem-focused coping. These differences do not detract from the substantial improvement found for both groups, but they do reinforce the conclusion that the specialized program was not more effective than its standard counterpart.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Sex and drugs and nuclear war: secular, developmental and type A influences upon adolescents' fears of the nuclear threat, AIDS and drug addiction.

Researchers are divided over the significance of teenagers' expressed fear of nuclear war. This study of 3556 secondary school pupils examined whether (1) fear of nuclear war remains a feature of adolescent concern during the current east-west détente; (2) the examination of responses in a large sample reveals age and sex differences in such expressed fears; (3) worry about 'real world' issues like nuclear war, AIDS and drug addiction relates more generally to Type A proneness in adolescents. The results suggest that fewer teenagers spontaneously raise fear of nuclear war than in previous "pre-Glasnost" research in Britain, that such concern is expressed differentially according to the child's age and sex and that secondary school pupils who express concern about nuclear war and AIDS are more likely to show significantly higher Type A identification.

Acquired Immunodeficiency Syndrome↗
PubMed1993

When is a mug not a mug? Effects of content, naming, and instructions on children's drawings.

Two hundred seventy 5-year-old children produced a copy drawing of a transparent glass mug with its handle turned away. In a factorial design three factors were manipulated to examine their additive or independent influence on the child's production of either view-specific or canonical (i.e., with the handle at the side) depictions: the content of the mug, the label used to describe it, and the explicitness of instruction. The results showed, first, that each of these variations in task demands exerted an influence on the canonicality/view-specificity of the children's drawings. Second, these influences were both facilitative and prohibitive. So, for example, general instructions prompted canonical drawings, while very explicit instructions elicited view-specific depictions. Third, each factor exerted an independent influence upon whether or not the handle was included--there were no interactions between factors on the production of the two types of picture. These results provide further evidence against simple associations between children's drawings and their cognitive abilities. They suggest that what children produce in studies of "drawing" may well simply inform us about the development of an understanding of adults' communicative intent.

Age Factors↗
PubMed1993

Molecular heterogeneity of a Graves' thyroid-infiltrating T cell population rich in CD8+ and gamma delta+ T cells.

We report here on the isolation and repertoire characterization of a Graves' thyroid T cell population which, unlike most Graves' thyroid T cell isolates reported before, was rich in CD4-CD8- T cells (16%, all TcR gamma delta+) and CD8+ T cells (75%) [TcR alpha beta+ (59%) and TcR gamma delta+ (16%)]. Only 7% of the isolated T cells were CD4+. By contrast, < 2% of peripheral blood mononuclear cells from the same patient were gamma delta+ and < 14% were CD8+. Sequence analysis of 18 TcR delta cDNAs prepared from these cells indicated the presence of at least 17 different gamma delta+ T cell clonotypes with molecularly heterogeneous antigen-binding site sequences. As opposed to most peripheral blood gamma delta+ T cells (express V delta 2 TcRs), 13 of the 17 different TcR delta clonotypes used a V delta 1 gene, although PCR amplification of TcR gamma- and TcR delta-specific cDNAs with V delta- and V gamma-gene family-specific oligonucleotides confirmed usage of all 4 V gamma and all 6 V delta families. Sequence analysis of 21 TcR alpha cDNAs from a TcR alpha-specific cDNA library indicated the presence of at least 12 different clonotypes, using 8 different V alpha gene families and heterogeneous antigen-binding site sequences. These results are in contrast with the selective V alpha gene usage reported for other intrathyroidal T cell subpopulations in autoimmune thyroid disease.

Adolescent↗
PubMed1993

The first transplantation of the lung in a human revisited.

The first homotransplantation of the lung in a human was performed in early 1963, thirty years ago. It is the purpose of this review to evaluate the significance of this event and to determine its effects on the further development of lung transplantation.

History, 20th Century↗
PubMed1993

Validity of cardiovascular disease risk factors assessed by telephone survey: the Behavioral Risk Factor Survey.

The Behavioral Risk Factor Surveillance System (BRFSS) collects telephone interview data on behaviors for the leading causes of premature death and disability. Its validity has never been adequately studied. The authors replicated BRFSS methodology to validate self-reported cardiovascular disease (CVD) risk factors. Nine-hundred and eleven subjects from three upstate New York counties were interviewed between 1/89 and 5/90. Interviewees were offered physical examinations and laboratory testing for CVD risk factors; 282 men and 344 women participated. The authors studied validity by comparing objectively measured to self-reported CVD risk factors. Sensitivities for self-reported hypertension, hypercholesterolemia, obesity, smoking, and diabetes were: 43, 44, 74, 82 and 75%, respectively. Only smoking sensitivity differed by gender: men, 77%; women, 86%. Specificity was > 85% for all risk factors, except hypercholesterolemia in men (75%). Prevalence was underreported for hypertension, hypercholesterolemia, obesity, and smoking by 43, 50, 25 and 17%, respectively. Results suggest telephone survey research includes physiologic measurements for blood pressure, cholesterol, height, weight, and smoking to validate self-reported CVD risk factors. When this is impossible, results such as these can be used, in similar samples, to correct risk factor prevalence rates from telephone surveys for misclassifications.

Adult↗
PubMed1993

A phytoestrogen diet induces the premature anovulatory syndrome in lactationally exposed female rats.

The effects of a phytoestrogen diet on sexual differentiation were examined in lactationally exposed rat pups. Rat dams were provided a semipurified diet containing the isoflavonoid coumestrol at a concentration (0.01%) previously found to be uterotrophic. Coumestrol treatment did not significantly alter the time of vaginal opening, although vaginal opening did occur at a lighter body weight. By 132 days of age, 83% of coumestrol-treated females exhibited the cornified smears of a persistent estrous state. By contrast, 91% of control animals were cycling regularly at 132 days of age. Estradiol stimulation failed to elicit an LH elevation in the coumestrol-treated animals, suggesting the possibility of neuroendocrine impairments. These findings indicate that the female offspring of mothers fed a low-level phytoestrogen diet during lactation manifest early and nearly universal disruption of cyclicity of the persistent-estrus type.

Animals↗