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Biomedical subjects

C Davis

Publications and source records attributed to C Davis.

At least 19 recordsLinked to original sources
PubMed1992

Transcultural aspects of eating disorders: a critical literature review.

A review of studies addressing anorexia nervosa and bulimia nervosa among Native Americans, African-Americans, Hispanics, Asians, Africans, and Middle Easterners yielded only 35 studies, of which 22 were qualitative case reports, three were clinical quantitative studies, and ten were non-clinical quantitative studies. The case studies reported symptoms similar to those of Caucasian patients, and eating disorders were reported in all SES classes. The clinical studies, all reported from Asian countries, described a number of cases for eating disorders quite different from one another. The non-clinical quantitative studies reported a number of cases consistent with the ranges previously reported for controlled samples of non-clinical Caucasian populations. We found few or no quantitative studies on eating disorders from Hispanic, Middle Eastern, African, or Asian countries other than Japan.

Adolescent↗
PubMed1992

Distinguishing ischemic cardiomyopathy from nonischemic dilated cardiomyopathy with coronary echocardiography.

Transthoracic echocardiographic examination of the proximal left coronary system was performed in 59 patients who had dilated cardiomyopathy to determine if this technique could distinguish between ischemic and nonischemic dilated cardiomyopathy. With use of annular array transducers (3.5 or 5 MHz) and digital image processing, echocardiographic visualization of the coronary arteries was successful in 55 (93%) of 59 patients. As assessed by coronary angiography, 32 subjects had ischemic cardiomyopathy and 27 had nonischemic cardiomyopathy. Twenty-seven (84%) of the 32 patients who had coronary artery disease and 24 (89%) of the 27 patients with nonischemic cardiomyopathy were correctly identified. The accuracy of coronary echocardiography was 86% in the entire study group and 93% when patients with inadequate studies were excluded. All subjects who had ischemic cardiomyopathy had evidence of disease by coronary echocardiography or segmental wall motion abnormalities. Multivariate analysis permitted correct classification of 93% of all subjects based on the results of the coronary echocardiogram, evaluation of segmental wall motion and a history of prior myocardial infarction. The correct diagnosis was made in 86% when the results of coronary echocardiography were excluded from analysis using all other echocardiographic and clinical variables. Transthoracic coronary echocardiography can be performed with a high degree of success in patients with dilated ventricles and the technique can reliably distinguish between ischemic and nonischemic dilated cardiomyopathy.

Cardiomyopathy, Dilated↗
PubMed1992

Phase II study of pulse 5-fluoro-2'-deoxyuridine and leucovorin in advanced colorectal cancer patients previously treated with chemotherapy.

Because of possibly better activity against colorectal cancer of 5-fluoro-2'-deoxyuridine [floxuridine (FUdR)] compared to 5-fluorouracil (5-FU), and because of improved therapeutic results of leucovorin (LV) modulation of 5-FU, we carried out a phase II study of systemic FUdR and LV in 5-FU-treated patients with metastatic colorectal cancer. Weekly regimens consisted of a 4-hour infusion of LV, 200 mg/m2, and at 2 hours, a 2-hour infusion of FUdR, 30 mg/kg, with weekly dose escalation, as tolerated, to a maximum of 60 mg/kg. Twenty-nine patients were treated; they had a median age of 66, most had good performance status, and all had measurable disease. All had received 5-FU, although three had received it as adjuvant therapy only. Two patients had partial responses (6.9% response rate, 95% confidence interval, 1.9-21.9%) lasting 29 and 19 weeks, and five had stable disease. Median time to progression was 8 weeks and median survival was 36.5 weeks. The median number of courses was 6.5; escalation of FUdR was carried out in 27 patients. Hematologic toxicity was minimal and gastrointestinal toxicity was most frequent, although mild. This regimen, although well tolerated, is minimally effective in previously 5-FU-treated patients with metastatic colorectal cancer.

Adenocarcinoma↗
PubMed1992

Psychopathic disordered, mentally ill, and mentally handicapped sex offenders: a comparative study.

Although there currently exists a large amount of research on the characteristics and treatment of psychopathic disordered (PD) sex offenders, little if any empirical studies have addressed the mentally ill (MI) and mentally handicapped (MH) offender populations. A total of 106 PD, MI, and MH sex offender records from Rampton (Special) Hospital were reviewed for the study. Offender categories were compared by age of first documented sex offence, IQ at the time of admission, sex offence type, frequency of each offence type, history of violence during sex offences, age and gender of sex offence victims and number of victims for age and gender. Results revealed that 88 per cent of PD, 98 per cent of MI, and only 56 per cent of MH offenders' victims were female. Further analysis revealed that PD and MI offenders' victims were primarily female, with the largest proportion being pubescent and adult females. MH offender victims were primarily males and females under the age of 16. IQ correlated positively with history of violence during sexual assault and mean IQs were higher for 'violent' than 'non-violent' offenders in each offender category. A discussion of these and other significant findings, as well as implications for clinical treatment, is presented.

Adolescent↗
PubMed1992

Predictors of HIV-1 disease progression in early- and late-stage patients: the U.S. Army Natural History Cohort. Military Medical Consortium for Applied Retrovirology.

HIV-infected individuals in both early and late stages of HIV disease were evaluated over 2 years to assess temporal trends and determinants of disease progression. The Walter Reed (WR) staging system was used to categorize patients into an early-stage cohort (WR Stages 1 and 2, N = 1183) and a late-stage cohort (WR Stage 5, N = 260) based on the initial clinical evaluation. Progression was defined as the occurrence of Stage 5 disease or beyond for the early cohort and Stage 6 disease or beyond for the late cohort. The cumulative incidence of progression was 15.7% (137 events) for the early-stage cohort, and 53.7% (85 events) for the late-stage cohort. Baseline CD4+ T lymphocyte (T4) count was the most significant marker of progression: 26% of WR Stage 1 or 2 patients with T4 lymphocytes below 500/mm3 progressed, compared with 12% with T4 lymphocytes at or above 500/mm3. In late-stage individuals, 83% with T4 lymphocytes under 200/mm3 progressed, compared with 27% with T4 lymphocytes at or above 200/mm3. Older age was associated with progression in both early- and late-stage groups. Differences in the rates of disease progression were not significant between blacks and whites or between men and women. Two-year rates of progression among the late-stage patients dropped from 78 to 47% between 1986 and 1988. This contrasted with progression rates in the early-stage cohort, which remained stable: 18% for those entering follow-up in 1986 and 17% for those entering follow-up in 1988. These data indicate a significant slowing of HIV disease progression rates and mortality rates among individuals with late-stage disease that is temporally associated with the increased availability and use of therapies. With control of T4 lymphocyte count, age, and calendar time, neither gender nor race was significantly associated with progression in either early- or late-stage patients.

Adolescent↗
PubMed1992

Trypanosoma cruzi in wild raccoons and opossums in North Carolina.

Trypanosoma cruzi was isolated from 1 of 12 (8.3%) opossums and 3 of 20 (15%) raccoons from the piedmont area of North Carolina. Although T. cruzi has been isolated previously from wild mammals in the southern United States, the present study is the first published report of naturally occurring T. cruzi infection of wild mammals in North Carolina. All 4 isolates were maintained successfully in axenic culture and in murine fibroblasts. In addition, intraperitoneal injection of 1 x 10(6) culture forms of 1 of the opossum isolates into C3H mice resulted in low but detectable parasitemias as early as day 6 of infection. These mice resolved parasitemia and survived infection. Intraperitoneal injection of 1 x 10(6) culture forms of a raccoon isolate resulted in the death of 3 out of 4 mice. Surprisingly, parasitemias were never detected in the peripheral blood of these mice. Infection of murine fibroblasts in vitro resulted in the presence of intracellular amastigote stages characteristic of T. cruzi.

Animals↗
PubMed1991

Preparation of representative homogenates of biological tissues: effect of salt on protein extraction.

A technique for the preparation of representative homogenates of tissues is described. For most soft tissues and biological fluids (liver, kidney, semen) more than 80% of protein was recovered after homogenization in isotonic buffer. With tissues that are harder to homogenize, such as heart, spleen, and skeletal muscle, however, only approximately 40-50% of protein was extracted in this medium. Inclusion of salt or salt plus detergent during the homogenization increased recovery of the protein to levels close to those recorded with soft tissues. The increase represented a true recovery and was not an artifact induced by salt/detergent. This situation is parallel to previously reported results for lipid-rich biological tissues.

Animals↗
PubMed1991

A phase I evaluation of the safety and immunogenicity of vaccination with recombinant gp160 in patients with early human immunodeficiency virus infection. Military Medical Consortium for Applied Retroviral Research.

BACKGROUND: Despite multiple antiviral humoral and cellular immune responses, infection with the human immunodeficiency virus (HIV) results in a progressively debilitating disease. We hypothesized that a more effective immune response could be generated by post-infection vaccination with HIV-specific antigens. METHODS: We performed a phase I trial of the safety and immunogenicity of a vaccine prepared from molecularly cloned envelope protein, gp160, in 30 volunteer subjects with HIV infection in Walter Reed stage 1 or 2. The vaccine was administered either on days 0, 30, and 120 or on days 0, 30, 60, 120, 150, and 180. HIV-specific humoral and cellular immune responses were measured; local and systemic reactions to vaccination, including general measures of immune function, were monitored. RESULTS: In 19 of the 30 subjects both humoral and cellular immunity to HIV envelope proteins increased in response to vaccination with gp160. Seroconversion to selected envelope epitopes was observed, as were new T-cell proliferative responses to gp160. Response was associated with the CD4 cell count determined before vaccination (13 of 16 subjects [81 percent] with greater than 600 cells per milliliter responded, as compared with 6 of 14 [43 percent] with less than or equal to 600 cells per milliliter; P = 0.07) and with the number of injections administered (87 percent of subjects randomly assigned to receive six injections responded, as compared with 40 percent of those assigned to three injections; P = 0.02). Local reactions at the site of injection were mild. There were no adverse systemic reactions, including diminution of general in vitro or in vivo cellular immune function. After 10 months of follow-up, the mean CD4 count had not decreased in the 19 subjects who responded, but it had decreased by 7.3 percent in the 11 who did not respond. CONCLUSIONS: This gp160 vaccine is safe and immunogenic in volunteer patients with early HIV infection. Although it is too early to know whether this approach will be clinically useful, further scientific and therapeutic evaluation of HIV-specific vaccine therapy is warranted. Similar vaccines may prove to be effective for other chronic infections.

Adolescent↗
PubMed1991

A novel strategy for the generation of T cell lines lacking expression of endogenous alpha- and/or beta-chain T cell receptor genes.

Mutant T cell lines that do not express the endogenous alpha- and/or beta-chain genes of the TCR were generated from the alpha beta TCR/CD3+ tumor cell line C6VL with a combination of classical mutagenesis methods and selection of somatic hybrid variants. This novel strategy obviated the need for repeated mutagenesis and screening of a large number of individual clones. The loss of either the alpha- or the beta-chain expression in the mutant cells was associated with the loss of surface TCR/CD3 complex, which could be rescued by the transfection of appropriate exogenous alpha- and/or beta-chain gene constructs. Because these cells express a single TCR molecule on the cell surface, they are useful for the study of the assembly and function of the alpha beta TCR. This strategy is also generally applicable for the generation of homozygous mutant cell lines lacking other gene products.

Animals↗
PubMed1991

High-dose cisplatin plus dacarbazine in the treatment of metastatic melanoma.

The combination of cisplatin plus dacarbazine (DTIC) is active in metastatic melanoma with response rates reported between 10% and 55%. To optimize this regimen, a Phase II study was conducted employing a dose intensity of cisplatin higher than previously reported. Twenty-two patients were treated. Eight patients received cisplatin 100 mg/m2 on days 1 and 8 combined with DTIC 300 mg/m2 on days 1, 2, 8 and 9 (regimen A). Because of excessive toxicity, the protocol was modified so that cisplatin was given at 50 mg/m2 per day and DTIC 350 mg/m2 per day on days 1 through 3 (regimen B). The overall response rate was 32% and consisted of four partial and three complete responses (CR). The median duration of response was 6 months. Two of the CR remain in sustained, unmaintained remission in excess of 1.5 years. All seven patients that responded were treated on regimen B. High-dose cisplatin plus DTIC on a 3-day schedule represents an effective, well-tolerated therapy for metastatic melanoma.

Adult↗
PubMed1991

Tumor necrosis factor and endotoxin can cause neutrophil activation through separate pathways.

We investigated the possibility that tumor necrosis factor (TNF) mediates neutrophil activation by endotoxin. The number of C3b receptors on the neutrophil cell-surface was used as the indicator of activation, as assessed by indirect immunofluorescence. Incubation of buffy-coat neutrophils with TNF-alpha for 30 minutes at 37 degrees C caused neutrophil activation, increasing C3b receptor-dependent fluorescence from 340 with buffer alone to 580 with TNF (250 pg/mL). Increasing amounts of anti-TNF IgG progressively inhibited neutrophil activation by TNF (250 pg/mL). Addition of the active dose range of anti-TNF to neutrophils incubating in endotoxin (10 ng/mL) did not affect the degree of endotoxin-mediated neutrophil activation. Mixtures of neutrophils with the 50% suppressive dose of anti-TNF and varying endotoxin concentrations showed the same degree of neutrophil activation as mixtures without the antibody. Thus, an antibody that can inhibit TNF-mediated neutrophil activation does not inhibit endotoxin-mediated neutrophil activation. We conclude that endotoxin and TNF can activate neutrophils through separate pathways.

Antibodies↗