Biomedical subjects

V Baker

Publications and source records attributed to V Baker.

At least 19 recordsLinked to original sources

PubMed2001

Enhancing recall of information from a patient education booklet: a trial using cardiomyopathy patients.

A quasi-experimental trial was conducted to compare the effect on information recall of: (a) the use of adjunct questions (AQ) in printed materials; and (b) a procedure (the 5Rs) for integrating printed patient education materials into face-to-face teaching. A total of 51 patients with severe left ventricular failure (cardiomyopathy) was assigned to one of three groups (n=17). Each group worked with a purpose-prepared booklet, the first in association with the 5Rs procedure; the second group with a version of the booklet containing adjunct questions; and the third with a text only version of the booklet. Recall of information from the booklet was measured using a checklist scored on the basis of responses secured in a standardised interview. Improved recall was associated with both the adjunct questions and the 5Rs procedure, with the latter achieving a substantially superior outcome. The practical implications of these findings are presented and directions for further research indicated.

Analysis of Variance↗

PubMed2001

Cytochrome P450 expression and related metabolism in human buccal mucosa.

Constituents in food and fluids, tobacco chemicals and many drugs are candidates for oral absorption and oxidative metabolism. On this basis, the expression of cytochrome P450 isozymes (CYPs) and the conversion of CYP substrates were analysed in reference to buccal mucosa. A RT-PCR based analysis of human buccal tissue from 13 individuals demonstrated consistent expression of mRNA for the CYPs 1A1, 1A2, 2C, 2E1, 3A4/7 and 3A5. CYP 2D6 was expressed in six out of the 13 specimens, whereas all samples were negative for 2A6 and 2B6. Serum-free monolayer cultures of the Siman virus 40 large T-antigen-immortalized SVpgC2a and the carcinoma SqCC/Y1 buccal keratinocyte lines expressed the same CYPs as tissue except 3A4/7 and 3A5 (SVpgC2a), and 2C, 2D6 and 3A4/7 (SqCC/Y1). Dealkylation of ethoxyresorufin and methoxyresorufin in both normal and transformed cells indicated functional 1A1 and 1A2, respectively. SVpgC2a showed similar activity as normal keratinocytes for both substrates, whereas SqCC/Y1 showed about 2-fold lower 7-ethoxyresorufin O-deethylation and 7-methoxyresorufin O-demethylation activities. SVpgC2a showed detectable and many-fold higher activity than the other cell types towards chlorzoxazone, a substrate for 2E1. Absent or minute catalytic activity of 2C9, 2D6 and 3A4 in the various cell types was indicated by lack of detectable diclofenac, dextromethorphan and testosterone metabolism (<0.2-0.5 pmol/min/mg). Metabolic activation of the tobacco-specific N-nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and the mycotoxin aflatoxin B1 (AFB1) to covalently bound adducts was indicated by autoradiographic analysis of both monolayer and organotypic cultures of SVpgC2a. In contrast, SqCC/Y1 showed lower or absent metabolic activity for these substrates. Finally, measurements of various non-reactive AFB1 metabolites indicated rates of formation <0.1 pmol/min/mg in both normal and transformed cells. The results indicate presence of several CYPs of which some may contribute to significant xenobiotic metabolism in human buccal epithelium. Notably, metabolic activation of AFB1 was not previously implicated for oral mucosa. Further, the results show that CYP-dependent metabolism can be preserved or even activated in immortalized keratinocytes. Metabolic activity in SVpgC2a under both monolayer and organotypic culture conditions suggests that this cell line may be useful to pharmaco-toxicological and carcinogenesis studies.

Aflatoxin B1↗

PubMed2000

Standing orders for influenza vaccination increased vaccination rates in inpatient settings compared with community rates.

BACKGROUND: Hospitalization of older adults during the period of influenza vaccination in the fall of each year presents a barrier to immunization against influenza. This study evaluates a program using standing orders for influenza vaccination to increase vaccination rates among hospitalized older adults and to determine the effect of vaccination on readmission rates for influenza-like illness. METHODS: An influenza vaccination program using a standing order policy was implemented to vaccinate all consenting persons 65 years and older prior to hospital discharge. This was a prospective, single center, cohort study in a tertiary care university teaching hospital during an 8-week vaccination period in the fall of 1994 and follow-up during the subsequent influenza season. The vaccination status of each patient was recorded as no vaccination, vaccination received in hospital, or vaccination in the community prior to or after the hospitalization. Hospital vaccination rates were compared with the rate of vaccination of older adults in the community. During the subsequent influenza season, the number of subjects reporting symptoms of influenza-like illness (ILI) or who were readmitted to hospital with influenza-related illness was compared in an analysis of vaccinated versus unvaccinated subjects. RESULTS: Seven hundred and sixty-one patients were interviewed, and 332 of these individuals had been vaccinated in the community prior to their hospital admission. Of the remaining 429 unvaccinated patients who were eligible for vaccination in the study, 171 were vaccinated in our immunization program, eight were vaccinated in the community after discharge, and 244 were not vaccinated. We were able to increase the absolute vaccination rate by 22%, when compared with community rates, with our immunization program. The number of subjects with ILI symptoms or readmission to hospital was too small to compare the vaccinated to the unvaccinated group in the study. CONCLUSIONS: An inpatient influenza immunization program using a standing order policy was able to target a particularly high-risk subset of persons 65 years and over who might otherwise have not received influenza vaccination.

Aged↗

PubMed1998

Cancer of the corpus uteri in white and black women in Michigan, 1985-1994: an analysis of trends in incidence and mortality and their relation to histologic subtype and stage.

BACKGROUND: Cancer of the corpus uteri occurs more commonly among white women in the U.S., yet survival is poorer for black women. This study examined whether this trend has changed and also examined the relation of age and histologic subtype to differences in stage. METHODS: This retrospective cohort study assessed incidence trends, mortality trends, and the relation of age and histologic subtype to stage for 12,079 incident cases and 2325 deaths registered between 1985 and 1994 in Michigan. Rate ratios compared incidence and mortality. Odds ratios quantified the contribution of age and histologic subtype to differences in risk for advanced stage, using Mantel-Haenszel univariate techniques and multivariate logistic regression. RESULTS: The overall incidence rate was 21.99 per 100,000, and the overall mortality rate was 3.82 per 100,000. Black women had a 40% lower risk (rate ratio [RR] =0.60) of developing cancer of the corpus uteri but had a 54% greater risk (RR=1.54) of dying from cancer of the corpus uteri. Black women were at greater risk of being diagnosed with either sarcoma or more aggressive adenocarcinoma. However, after adjustment for age and histologic subtype, black women still had an increased risk for advanced stage disease (2.63, 95% confidence interval=2.19-3.16). CONCLUSIONS: The disparity between white and black women persists in incidence and mortality trends for cancer of the corpus uteri. The greater frequency of more aggressive histologic subtypes experienced by black women accounts for only 10% of their excess risk for more advanced stage disease.

Adenocarcinoma↗

PubMed1998

Bcl-xL is expressed in ovarian carcinoma and modulates chemotherapy-induced apoptosis.

OBJECTIVE: To investigate the role of Bcl-xL in resistance to chemotherapy-induced apoptosis in ovarian carcinoma. METHODS: Two human ovarian carcinoma cell lines were used in this study: A2780 and SKOV3. A2780 cells were transfected with human Bcl-xL or control plasmid alone. Expression of Bcl-xL in single cell clones was analyzed by flow cytometry and protein expression was confirmed by Western blot. For in vitro chemotherapy-induced death assays, cisplatin and Taxol were used. The percentage of apoptotic cells was determined by nuclear propidium iodide staining followed by flow cytometric analysis. Human ascites samples were used to make tumor lysates which were then analyzed for expression of Bcl-xL protein by Western blot. RESULTS: A2780 cells express low levels of endogenous Bcl-xL while SKOV3 cells express high amounts as determined by Western blot. In addition, A2780 cells are sensitive to chemotherapy-induced cell death while SKOV3 cells are resistant. To determine if chemoresistance is mediated by expression of Bcl-xL, A2780 cells were transfected with Bcl-xL or control plasmid. Cells were incubated with either cisplatin or Taxol to induce apoptosis. Bcl-xL-expressing cells were highly resistant to cisplatin and Taxol compared with controls (P < 0.05). All samples of malignant ascites analyzed expressed high levels of Bcl-xL on Western blot. CONCLUSIONS: The results of these studies indicate that Bcl-xL is expressed in ovarian carcinoma, and in A2780 cells functions in a manner analogous to Bcl-2 by inhibiting chemotherapy-induced apoptosis. This may have prognostic significance; previous studies have demonstrated that patients with breast cancer that overexpress Bcl-2 have low-grade, hormonally responsive tumors. In ovarian carcinoma, another Bcl-2 family member, Bcl-xL may be responsible for modulating resistance to chemotherapy-induced apoptosis.

Antineoplastic Agents↗

PubMed1997

Community care provision: data collection for planning.

The Core Community Dataset (CCDS) is being used by community healthcare practitioners to record care provision. This article describes the principles behind the system and examines how nurses can use the information defined in standard terms to inform care planning.

Community Health Nursing↗

PubMed1996

Ehrlichia-like 16S rDNA sequence from wild white-tailed deer (Odocoileus virginianus).

The reservoir hosts of Ehrlichia chaffeensis, etiologic agent of human ehrlichiosis are unknown. Initially, white-tailed deer (WTD) were serologically implicated as possible reservoirs of E. chaffeensis. Subsequent studies showed that WTD were susceptible to infection with E. chaffeensis and that deer-to-deer transmission by a tick vector, Amblyomma americanum, is possible under experimental conditions. To determine if wild WTD were infected with E. chaffeensis, whole blood was collected from 10 deer from Oklahoma and Georgia. All 10 deer had antibodies reactive to E. chaffeensis. Whereas E. chaffeensis was not isolated, restriction enzyme mapping and sequencing of the 16S rDNA gene revealed that a unique Ehrlichia-like agent was present. All 10 deer appeared to be infected with the same agent. We suspect that A. americanum is the vector of this new agent based upon the previously published temporal association between the appearance of E. chaffeensis seropositive WTD and A. americanum. However, the taxonomic and antigenic relationships, geographic distribution, epidemiology, and zoonotic potential of this agent are yet to be determined.

Animals↗

PubMed1993

Enzyme-linked immunosorbent assay of HER-2/neu gene product (p185) in breast cancer: its correlation with sex steroid receptors, cathepsin D and histologic grades.

One hundred and nine primary breast cancers were analyzed to assess the presence of the HER-2/neu gene product (p185), the oestrogen (ER) and the progesterone (PR) receptors, and the total cathepsin D status. An enzyme-linked immunosorbent assay (ELISA kit, Oncogene Science Inc.) was used for the evaluation of p185 in pellets obtained after a 100,000 x g centrifugation, ER and PR were measured by enzyme immunoassay (EIA kit, Abbott Laboratories), and the total cathepsin D content was evaluated by immunoradiometric assay (IRMA kit, CIS Biointernational). We showed that the ELISA kit is feasible to quantify the p185 present in breast cancer cell membranes, and that the detector antibody recognises a protein of apprroximatly M(r) 185,000. The detected antigen was inversely related to both ER and PR, but it did not correlate to total cathepsin D. No significant differences were found in the expression of p185, ER, PR, cathepsin D between infiltrating ductal carcinomas without special features (NOS) and non-ductal (non-NOS) carcinomas. Nevertheless, in NOS carcinomas, a trend was observed in the p185 levels expressed by the tumours with different histological grades, in that p185 concentration was higher in the poorly differentiated grade 3 with respect to grade 2 and grade 1.

Adult↗

PubMed1992

Transcriptionally active non-ligand binding oestrogen receptors in breast cancer.

Data were obtained on soluble oestrogen (ER) and progesterone (PR) receptors from 273 primary breast tumours, using an enzyme immunoassay (EIA) and ligand binding assay with dextran-coated charcoal (DCC) or isoelectric focussing separations. The p29 and total cathepsin D content was also assayed in the same samples. Tumours expressing ER (by either steroid binding assay or EIA) had higher levels of p29 than those which did not express the receptor (P < 0.0001). Moreover, tumours co-expressing ER, PR and p29 appeared to have higher levels of cathepsin D than those which were negative for at least one protein (P < 0.0001). Twenty out of the 273 human breast cancer samples, containing a level of ER positive by EIA, which did not bind labelled oestradiol, were identified; isoelectric focussing showed that such a receptor was also unable to bind hydroxytamoxifen. These tumours did not significantly differ from those in the whole population in their capacity to express ER (positive by EIA), PR, p29 and cathepsin D. It was concluded that the EIA can detect both a ligand binding ER and a receptor which is able to initiate PR transcription but does not bind radio-labelled ligands in vitro; such a receptor could have a bearing on the variability of tumour response to endocrine therapy.

Biomarkers, Tumor↗

PubMed1992

Oral folic acid supplementation for cervical dysplasia: a clinical intervention trial.

OBJECTIVE: We attempted to evaluate the effect of oral folic acid supplementation on the course of cervical dysplasia. STUDY DESIGN: A total of 235 subjects with grade 1 or 2 cervical intraepithelial neoplasia were randomly assigned to receive either 10 mg of folic acid or a placebo daily for 6 months. Clinical status, human papillomavirus type 16 infection, and blood folate levels were monitored at 2-month intervals. Outcome data were subjected to chi 2 analysis. RESULTS: The prevalence of human papillomavirus type 16 infection initially was 16% among subjects in the upper tertile of red blood cell folate versus 37% in the lower tertile (trend p = 0.035). After 6 months no significant differences were observed between supplemented and unsupplemented subjects regarding dysplasia status, biopsy results, or prevalence of human papillomavirus type 16 infection. CONCLUSION: Folate deficiency may be involved as a cocarcinogen during the initiation of cervical dysplasia, but folic acid supplements do not alter the course of established disease.

Administration, Oral↗

PubMed1992

Electrocardiogram of the humpback whale (Megaptera novaeangliae), with specific reference to atrioventricular transmission and ventricular excitation.

OBJECTIVES: The objective of the study was to record the electrocardiogram (ECG) of a large whale to obtain crucial data for comparative electrophysiologic analysis. BACKGROUND: The data were needed to establish the mismatch between heart size and PR interval and QRS duration in mammals. METHODS: In the waters off the coast of Newfoundland, in two humpback whales (Megaptera novaeangliae) with an estimated weight of 30,000 kg a 1-lead ECG was recorded, enabling reliable assessment of P waves and QRS complexes. RESULTS: It was found that both the PR interval (atrioventricular [AV] transmission time) and QRS duration (ventricular excitation) are extremely short for animals of this size. These findings are difficult, if not impossible, to explain on the basis of currently accepted electrophysiologic theories. However, the narrow QRS complex may be due to a very dense His-Purkinje network in the ventricular wall of whales. Alternative mechanisms that can explain the function of the mammalian AV node need to be considered and explored. CONCLUSIONS: The results of the study may be of value for the understanding of the ECG in humans.

Animals↗

PubMed1992

Oncogenes in gynecologic malignancy.

The identification and characterization of protooncogenes and tumor suppressor genes have provided important insights into the mechanisms of control of normal and abnormal cell growth and differentiation. As a consequence, significant advances have been made in our understanding of the initiation of gynecologic malignancies at the molecular level, particularly cervical cancer. In addition, the identification of specific genetic mutations of protooncogenes and tumor suppressor genes in some gynecologic malignancies appears to be of prognostic significance. The English language literature published during the past year concerning oncogenes and tumor suppressor genes in gynecologic malignancies is reviewed.

Female↗

PubMed1991

Human papillomavirus screening for women with atypical Papanicolaou smears.

A study was undertaken to evaluate the utility of human papillomavirus (HPV) DNA screening and colposcopy in the management of women whose Papanicolaou smears demonstrated atypia less than dysplasia. Fifty patients whose initial Papanicolaou smears were interpreted as showing atypia less than dysplasia were evaluated for the presence of HPV 16 DNA in exfoliated cervicovaginal cells and for histologic findings on biopsy. Those 50 patients were compared to two groups of patients: one consisting of 124 patients with biopsy-documented cervical intraepithelial neoplasia (CIN) and another of 112 patients with normal Papanicolaou smears. The presence of HPV 16 DNA was confirmed with Southern analysis in 46% of patients with atypical Papanicolaou smears, 46% with confirmed CIN and 11.6% with normal Papanicolaou smears. The 50 patients with atypical smears underwent colposcopically directed cervical biopsies, revealing the following results: 14 (28%) had normal histology, 29 (58%) had koilocytosis without dysplasia, and 7 (14%) had CIN. HPV 16 DNA was present in exfoliated cervicovaginal cells from a large percentage of patients from each category (50% of patients with normal histology, 41.2% with koilocytosis and 57% with CIN). HPV 16 DNA screening did not predict which patients with atypical smears had underlying CIN. Colposcopically directed biopsy remains the evaluation method of choice.

Adolescent↗

PubMed1991

Cell cycle kinetic studies in human cancers. Development of three DNA-specific labels in three decades.

Controversy has epitomized the prognostic and clinical significance accorded to cell cycle kinetic studies in neoplastic diseases. Recent introduction of monoclonal antibodies to thymidine analogues such as iododeoxyuridine and bromodeoxyuridine has unveiled a spectacular new area of research. Large numbers of patients with liquid and solid tumors have been interrogated by introducing iododeoxyuridine and bromodeoxyuridine as DNA-specific probes in vivo. Further in vitro incubation of S-phase cells already double-labeled in vivo with tritiated thymidine has added a whole new dimension to the kinds of questions that can now be addressed with alacrity. Time is rapidly approaching when this information will be available in a prompt enough fashion to be useful for planning therapeutic strategies. Reviewed are the salient features of the rapid progress achieved in the last decade in this exciting discipline.

Acute Disease↗

PubMed1989

Dissociation of cellular proliferation and c-myc expression by buttercup extract.

Buttercup extract (BE), an extract of the buttercup plant (Zanthoriza simplicissima), inhibits RNA and DNA synthesis by HL-60 promyelocytic leukemia cells. Exposure of these cells to 3% BE for 48 hours results in dramatic inhibition of RNA synthesis without loss of cell viability. The effect of BE is partially reversible over 12-24 hours with the level of RNA synthesis returning nearly to control levels during this time period. DNA synthesis is also reversibly inhibited by exposure to BE. Despite the inhibition of RNA synthesis in HL-60 cells, there is no decrease in the level of c-myc mRNA, even at high BE concentrations. The level of gene-specific mRNA for the c-Ha-ras, c-fms, and c-mos genes in these cells also remained constant during exposure to BE. Ribosomal RNA is not degraded during 24 hours of BE treatment in vitro, suggesting that BE does not maintain the relative mRNA level for these genes by selective degradation of other RNA species. The inhibition of RNA and DNA synthesis by BE without a corresponding alteration in the level of expression of the c-myc gene suggests that this agent dissociates c-myc expression and cellular proliferation in these cells.

Cell Division↗

PubMed1986

Basic mechanisms of metastasis.

Metastatic disease is responsible for the majority of deaths caused by cancer. The process of metastasis is an orderly, stepwise process that results in the selection of cells that possess the capability to establish viable metastases. These cells must be locally invasive and be able to survive the physical traumas of dissemination and normal host defenses. Once metastatic cells have been arrested in a capillary bed, they must be able to invade the host organ parenchyma and survive in that milieu. Studies in a number of model systems have documented the phenotypic alterations in cells that have "metastatic potential." These differences may stem from normal tumor cell heterogeneity and surprisingly reflect only minor differences in gene expression. The role of activated oncogenes in metastasis is unclear, but a number of laboratories have documented that transfection with activated Ha-Ras results in increased metastatic potential. An increased understanding of the genetic basis of metastatic potential may suggest new directions for intervening in this deadly process.

Humans↗

PubMed1984

Contrasts in the professional identities of psychiatrists and internists.

Projected manpower shortages in psychiatry have prompted studies identifying factors that influence medical students in career choice. In the present study, the authors compare self-images as individuals with professional images of psychiatrists using subjects from internal medicine as a control group. A total of 353 subjects from two university clinical practices completed questionnaires that utilized the Osgood Semantic Differential to determine attitudes in the areas of evaluation, potency, and activity. The hypothesis that psychiatrists differ significantly in their self-images as individuals and their professional role images was partially confirmed. In the areas of activity and power, significant (p less than .001) differences existed in their attitudes. In the concept of evaluation, the self-images and the professional images were similar. The impact of these discrepancies on students making career choices is discussed.

Career Choice↗

PubMed1983

Transcriptional regulation of two genes specifically induced by glucose starvation in a hamster mutant fibroblast cell line.

This report concerns the characterization of the RNA transcripts encoded by two cDNA sequences p4A3 and p3C5, derived from a hamster temperature-sensitive mutant cell line K12. Using the two cDNA sequences as hybridization probes, we show that they occur as single copy genes in the hamster genome and encode for RNA transcripts which are highly inducible in K12 cells at 40.5 degrees C. After incubation at 40.5 degrees C for 16 h, there is a 10-fold increase in the p4A3 and p3C5 mRNA levels, reaching a final concentration of about 1% of the cytoplasmic polyadenylated RNA. We demonstrate that the kinetics of transcription of p4A3 and p3C5 directly parallel the accumulation of the mRNA levels at 40.5 degrees C. Thus, our data indicate that the expression of these two genes are primarily regulated at the transcriptional level. In addition, there is a 3- to 4-fold increase in the p4A3 and p3C5 mRNA levels when the cells are specifically starved of glucose. This implies that the expression of these two genes are stringently regulated by the availability of glucose in the culture medium. The relationship between the cDNA clones and two glucose-regulated proteins which are overproduced in K12 cells at 40.5 degrees C is discussed.

Animals↗