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Biomedical subjects

M D Thomas

Publications and source records attributed to M D Thomas.

At least 19 recordsLinked to original sources
PubMed2001

Contraceptive use and attitudes toward family planning in Navy enlisted women and men.

Little is known about the contraceptive behavior and beliefs of Navy personnel. Nevertheless, the Navy, in its role as primary medical provider for its personnel, needs to know whether sailors have access to effective birth control and are sufficiently informed about contraception to make wise choices. As part of the Women Aboard Navy Ships Comprehensive Health and Readiness Project conducted at the Naval Health Research Center in San Diego, California, contraceptive use and attitudes toward family planning were assessed through a survey administered to 714 enlisted women and 665 enlisted men on 15 ships. Contraceptive use was not related to gender, age, marital status, pay grade, race, or education. More favorable family planning attitudes were related to contraceptive use. Women and men differed in their attitudes toward family planning, with women's responses more positive than men's. The results highlight the need for research focusing on the effect of attitudes on contraceptive behavior.

Adult↗
PubMed2000

Identifying the predictors of acute urinary retention following magnetic-resonance-guided prostate brachytherapy.

PURPOSE: Larger prostate gland volumes have been associated with long-term urinary morbidity in prostate interstitial radiation therapy utilizing ultrasound image guidance technique. This study was performed to identify the clinical and technical predictors of acute urinary retention following magnetic-resonance (MR)-guided prostate interstitial brachytherapy. METHODS AND MATERIALS: Fifty patients underwent MR-guided prostate brachytherapy between December 1997 and March 1999. Patient selection was limited to men with stage T1cNXM0 disease, PSA of less than10 ng/mL, biopsy Gleason score not more than 3 + 4, and endorectal coil MR stage T2 disease. Dosimetry plans were developed in the operating room and (125)Iodine sources were implanted using MR real-time guidance. The peripheral zone (PZ) of the prostate gland was defined as the clinical target volume (CTV) and the minimum prescribed dose to the CTV was 137 Gy. The volumes of the PZ, transition zone (TZ), and total prostate gland volume were also determined by MR. Individual source strength ranged from 0.35 to 0.54 microGym(2)/h (NIST 99, median 0.46 microGym(2)/h) and the total implanted activity ranged from 17.0 to 43.1 mCi (median, 28.1 mCi) using 43-120 seeds (median, 79). The seeds were placed using MR-compatible biopsy needles (14-28, median, 19). RESULTS: The ability of clinical (MR defined prostate, PZ, and TZ volumes) and technical (number of catheters, number of seeds implanted, and total activity) factors to predict AUR for 50 men undergoing MR-guided prostate interstitial brachytherapy were evaluated using univariable and logistic regression multivariable analyses. Six men (12%) experienced AUR within 24 h after removal of the Foley catheter subsequent to prostate brachytherapy. The total number of seeds (p = 0.05), MR determined prostate volume (p < 0.01), and the MR-determined TZ volume (p < 0.01) were significant predictors of AUR on univariable analysis. Utilizing a multivariable logistic regression analysis, the TZ volume was the only significant predictor of AUR (p < 0.01). The prostate volume is highly correlated to the TZ volume (Spearman correlation coefficient of 0. 91) and was thus significant in the univariable analysis; however, the prostate volume did not add prognostic value in multivariable analysis. CONCLUSION: Benign prostatic hyperplasia (BPH) resulting in an enlarged TZ volume, is the most important predictor of AUR following MR-guided prostate interstitial radiation therapy. Although AUR was significant (60%) in men with moderate BPH (TZ volume >/= 50 cc), it was also self-limiting.

Analysis of Variance↗
PubMed2000

Utilizing insider-outsider research teams in qualitative research.

Teams including members from both inside and outside the organization being studied make valuable contributions. A team configuration including both insiders and outsiders is highly effective because variations in the experience history of researchers on the team broaden the available perspectives and maximize the potential interpretations of observed behaviors. An insider-outsider research team consisting of university faculty and nurses at two psychiatric hospitals conducted a study, Meanings of State Hospital Nursing. This article summarizes the study, discusses issues to be resolved when using an insider-outsider research team, and presents the ways in which this approach enhanced the trustworthiness of our findings.

Adult↗
PubMed1999

Meanings of state hospital nursing. I: Facing challenges.

The purpose of this study was to describe the meaning of work for nurses employed in two state psychiatric hospitals. Nurses at both hospitals participated in designing and carrying out the research. In Phase I, nurses described situations in which they had been observers or participant observers and the way that they understood what was occurring in the situations described. The data from these descriptions were analyzed in collaboration with small groups of nurse co-investigators at each hospital. In Phase II, patterns of meaning identified in Phase I were checked and further refined based on focus groups and interviews with nurses at both hospitals. The interrelated dilemmas faced by nurses are discussed as (1) challenges in clinical decision making, (2) challenges regarding personal control, and (3) challenges of maintaining professional standards. Ways of meeting these challenges, coping, and making meaning are discussed in a companion article, "Meanings of State Hospital Nursing II: Coping and Making Meaning".

Focus Groups↗
PubMed1999

Meanings of state hospital nursing. II: Coping and making meaning.

The purpose of this study was to describe the meaning of work for nurses employed in two state psychiatric hospitals. A companion article, "Meanings of State Hospital Nursing I: Facing Challenges", (Archives of Psychiatric Nursing, 13(1), 48-54), describes the study methods and the findings regarding the challenges in clinical decision making, personal control, and maintaining professional standards that nurses face in state hospital nursing. This article focuses on the ways that nurses meet the challenges, cope, and make meaning. These methods include taking pride in being able to cope with the challenges, maintaining watchfulness, narrowing of focus, valuing the ideal when it does occur, and constructing personal meanings. The article concludes with suggestions for supporting and enhancing the ways in which nurses cope and make meaning in their daily work in state hospitals.

Adaptation, Psychological↗
PubMed1999

Preparing psychosocial nurse practitioners for health care delivery.

A central task for faculty in programs preparing health care practitioners is to remain timely in educating for the prevailing and future social and health services context. Current considerations in preparing advanced practice psychiatric nurses include the need for greater recognition of comorbidity, concerns about health care access and utilization for vulnerable populations, and changing patterns of practice. In addition, there is a great need to expand the cultural competence and diversity of the population of advanced practice nurses who deliver care to recipients in an increasingly multicultural society. This article describes the educational program developed at the University of Washington to prepare expanded role Psychosocial Nurse Practitioners and sets forth the rationale for major decisions and current directions.

Comorbidity↗
PubMed1999

Incorporating standardized patients into a psychosocial nurse practitioner program.

Interactions with standardized patients (SPs) provide customized, immediate clinical learning for graduate nursing students. SPs are lay persons trained to portray a role in a faculty-designed health care scenario for a series of students. Student learning results from the experience of the encounter, performance feedback from the SP, subsequent classroom discussion with peers, faculty critique, and review of the videotaped interaction. Design and implementation of an SP experience involves clarification of goals for the encounter, development of the clinical scenario, recruitment and training of SPs, preparation of students, and management of the logistics of the exercise. Although the process is labor-intensive, we have found SP experiences versatile, valuable, and popular with students.

Curriculum↗
PubMed1999

A human monoclonal antibody encoded by the V4-34 gene segment recognises melanoma-associated ganglioside via CDR3 and FWR1.

A heterohybridoma cell line producing the human monoclonal antibody (MoAb) MDT.1 has been established. The heavy chain of MoAb MDT.1 is encoded by the VH gene segment V4-34 (previously designated VH4-21), and the light chain is encoded by the V kappa 1-L12a gene segment, both in germline configuration. MDT.1 has reactivity against lipid A, double- and single-stranded DNA, red blood cell associated i antigen, and ganglioside antigens. In a panel of tumour cell lines, MDT.1 reacted specifically with melanoma cells and other tumour cells of neuroectodermal origin. Cellular recognition appears to be via tumour-associated ganglioside antigens, and may involve the minimal essential epitope NeuNac alpha 2-->3Gal beta 1-->-4Glc-. Binding to ganglioside antigen is inhibited by the monoclonal anti-idiotypic antibody 9G4. Since the 9G4 idiotope is located in framework region 1 (FWR1) of V4-34-encoded antibodies, this region is likely to be involved, either directly or indirectly, in ganglioside binding. The complementarity-determining region 3 (CDR3) of MDT.1 is arginine rich, with five out of 12 residues being arginine and these residues are candidates for interaction with the negatively charged ganglioside. The ability of MoAb MDT.1 to recognise ganglioside antigens is associated with potentially useful anti-tumour activity.

Amino Acid Sequence↗
PubMed1997

A novel quantitative immunoassay system for p53 using antibodies selected for optimum designation of p53 status.

AIM: To develop a highly sensitive and specific enzyme linked immunosorbent assay (ELISA) system for analysis of p53 protein in cancer lysates. METHODS: The anti-p53 monoclonal antibodies DO7, 1801, BP53.12, and 421, and anti-p53 polyclonal antiserum CM1 were assessed by immunohistochemistry and western blot analysis to identify those most suitable for determining p53 status of cancer cells. Antibodies with desired characteristics were used to develop a non-competitive sandwich type ELISA system for analysis of p53 expression in cancer cytosols. Using the ELISA, p53 protein concentrations were measured in a small series of breast cancers, and the quantitative values compared with p53 immunohistochemical data of the same cancers. RESULTS: DO7 and 1801 gave the most specific and reliable results on immunohistochemistry and western blot analysis. Using these two antibodies, a non-competitive sandwich type ELISA system was developed to analyse p53 quantitatively. Analysis of the breast cancer series showed a good correlation between immunohistochemistry and the ELISA-tumours were generally positive using both techniques. Discrepancies were noted however: some cancers were immunohistochemically negative but ELISA positive. One explanation for this may be that the ELISA is more sensitive than immunohistochemistry. CONCLUSION: The p53 ELISA system is a non-competitive double monoclonal antibody sandwich method, using DO7 and 1801 which have been shown to be highly specific for p53 protein by immunohistochemistry and western blot analysis. The lower threshold of the assay is 0.1 ng/ml analyte in an enriched recombinant p53 preparation. As p53 is now regarded as a protein associated with prognosis in breast and other cancers, the assay may have clinical applications.

Antibodies, Monoclonal↗
PubMed1996

Retinoblastoma protein in human breast carcinoma: immunohistochemical study using a new monoclonal antibody effective on routinely processed tissues.

Cyclic phosphorylation/dephosphorylation of the retinoblastoma gene product (pRB) has been found to play a central role in the progression of the normal cell cycle, through modulation of the activity of the E2F family of transcription factors. Mutations of the retinoblastoma gene have been described in a wide variety of human malignancies including carcinomas of the breast. The present investigation reports the production and application of a new monoclonal antibody in an immunohistochemical study of pRB expression in 233 primary breast carcinomas, allowing an assessment of the contribution made by this tumour suppressor gene to tumour development and progression. Overall, there was loss of pRB expression in 21 per cent of breast tumours. Although high-grade tumours were found to lack detectable pRB more frequently than low-grade tumours, the difference did not prove statistically significant. In addition, pRB immunostaining was not related significantly to relapse or survival. No significant correlations were observed between apparent loss of pRB and tumour size, parity, patient lymph-node status, p53, c-erbB-2, c-jun, EGFR or steroid hormone receptor expression. Preliminary findings, however, did suggest a relationship between pRB expression and response to endocrine therapy.

Adult↗
PubMed1996

p53 protein as a prognostic indicator in breast carcinoma: a comparison of four antibodies for immunohistochemistry.

We examined the reactivity of four p53-specific monoclonal antibodies--PAb 1801, p53-BP-12, D07 and CM1--on sections of formalin-fixed tissue collected from 245 breast carcinomas. Immunodetection of p53 varied between 37.6% and 46.6%. The greatest variation was observed among lobular carcinomas and low-grade tumors in which immunodetection varied between 8.3% and 27.3%. In contrast, immunodetection of p53 in invasive ductal carcinomas was subject to a lower degree of variability with between 40.6% and 49.7% of these tumours proving to be positive. In general, we found antibodies PAb 1801 and DO7 to be the most effective in immunolocalising p53. Immunodetection of p53 with each of the four antibodies was found to correlate strongly with tumour grade. In survival analysis, the results gained using antibody PAb 1801 proved to be of greatest statistical significance and to provide the strongest index of prognosis. A significant relationship was observed between immunodetection of p53 with each of the four antibodies and poor responsiveness to endocrine therapy. In addition, relationships were also observed between p53 immunostaining and tumour oestrogen receptor (ER) status as well as c-jun expression. We observed no correlation between abnormalities of the p53 and the Rb gene products or between elevated c-erbB-2 or epidermal growth factor receptor (EGFR) expression and immunodetection of p53.

Adult↗
PubMed1995

Determination of the prognostic value of cyclin D1 overexpression in breast cancer.

Cyclin D1 plays a critical role in the timing of the initiation of DNA synthesis in the normal cell cycle of mammalian cells. Deregulated expression of this protein has been seen in a variety of tumours either as a result of gene amplification or chromosomal translocation, in breast cancer and B cell malignancies respectively. In order to determine the role this putative oncoprotein plays in breast cancer, we have applied a new monoclonal antibody, recently produced in our laboratory, in an immunohistochemical study of 93 primary breast carcinomas. We show that approximately 28% of the cases displayed enhanced expression of the cyclin D1 protein. Furthermore, either cyclin D1, cyclin D3, or both, were expressed in 69% of cases, suggesting that overexpression of any one member of this family may relieve cancer cells of their mitogenic stimulatory requirement. In addition, we show that those patients whose breast cancers co-express cyclin D1 with either epidermal growth factor receptor (EGFR) or the retinoblastoma protein (pRB) have a significantly poorer prognosis in comparison to those expressing cyclin D1 alone. Our observations indicate that, in a subset of breast cancers, aberrant cyclin D1 expression is a contributory factor to tumorigenesis and in association with EGFR or pRB expression, identify those tumours which may require more aggressive therapy.

Animals↗