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M D Thomas

Publications and source records attributed to M D Thomas.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1993

The rise of public sector psychosocial nursing.

For a number of years, the Department of Psychosocial Nursing, University of Washington, engaged in a region-wide State-University collaboration with the Division of Mental Health authorities in states of the Pacific Northwest. This collaboration provided the basis for another 12 years of a Washington State Division of Mental Health-Department of Psychosocial Nursing contract to improve nursing in the state's two mental hospitals. This article describes the history, contractual relationships, and components of these projects. It concludes with a discussion of the consequences of these years of State-University cooperation, including conceptual issues, and the generation of the psychosocial nursing subspecialty, public sector psychosocial nursing.

Community Mental Health Services↗
PubMed1993

Production of Extracellular Proteins by the Biocontrol Fungus Gliocladium virens.

Gliocladium virens is a common saprophytic fungus that is mycoparasitic on a large number of fungi. Responses of G. virens toward its environment were examined by monitoring the presence of extracellular proteins in culture fluid during time course experiments. Culture fluid of G. virens grown on glucose, washed cell walls of Rhizoctonia solani (one of its hosts), olive oil, or chitin contained beta-glucanase, N-acetylglucosaminidase, lipase, and proteinase activities. There were relatively minor amounts of other enzymatic activities tested. Levels of extracellular enzyme activity varied with the age of the culture and the substrate used as the carbon source. Substrate-associated differences in enzyme activities were detected as early as 8 h after transfer of mycelia from stationary-phase cultures to fresh media. When G. virens was grown on host cell wall material, beta-glucanase had the greatest specific activity of any enzyme tested at 8 h. This result suggests that beta-glucanase may be the first enzyme important in the G. virens-R. solani interaction. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that some of the polypeptides were present in the culture fluid at relatively constant amounts and others accumulated early, at intermediate times, or late in the 8-day incubation test period. Several of the polypeptides present in the culture fluid during the first 24 h disappeared completely by 48 h. Consequently, it appears that extracellular proteins in cultures of G. virens are regulated by a combination of gene regulation and protein degradation.

Journal Article↗
PubMed1992

Laparoscopic orchiectomy for unilateral intra-abdominal testis.

We present 2 cases of laparoscopic removal of a unilateral intra-abdominal testis. Removal of a unilateral intra-abdominal testis is indicated in patients more than 10 years old because the malignant potential of an intra-abdominal testis outweighs any cosmetic benefit of orchiopexy. Laparoscopic orchiectomy is a safe and effective surgical procedure for adolescents and adults with this disease entity providing outpatient therapy and prompt rehabilitation.

Adult↗
PubMed1992

Subcloning using simplified adaptor addition.

A simplified procedure for the addition of synthetic oligonucleotide adaptors to subclone DNA fragments with incompatible ends is presented. An organophosphate degradation gene on a PstI fragment was cloned into the HindIII site of the fungal vector pH1S. The opd gene specifies parathion hydrolase and was first isolated from a Flavobacterium sp. The gene was present in 12% of the plasmids recovered and was inserted in either direction with similar frequencies: 53% with the opd start codon distal to the single SalI site of pH1S and 47% in the other orientation. All enzymatic steps were carried out in a single microconcentrator eliminating DNA loss through manipulation and transfer. Normally, during adaptor or linker addition, a larger number of oligonucleotides are attached at each end of the insert DNA and must be removed before cloning. The need for enzymatic digestion to remove excess adaptors was avoided. Traditional methods have utilized phenol/chloroform extraction, ethanol precipitation, gel filtration chromatography, spermine precipitation, or preparative gel electrophoresis. Eliminating these steps resulted in a simpler, more reliable procedure.

Base Sequence↗
PubMed1991

Pressure erosion of the femoral trochlea, patella baja, and altered patellar surfaces.

As knee flexion increases, so do tendofemoral and patellofemoral compression forces. Three cases of long-standing uncorrected flexion contractures of the knees are presented that resulted in marked erosion of the femoral trochlea, patella baja, and remodeled patellar articular surfaces likely reflecting increased angles of flexion. It is probable that the deep femoral grooves are the result of adaptation under high-level persistent contact loads from the quadriceps tendon. These examples expand our knowledge of bone remodeling and offer information of potential use in studying ancient skeletal samples.

Adult↗
PubMed1991

Major salivary gland lymphoepithelial lesions and the acquired immunodeficiency syndrome.

Presently, there is no consensus regarding the most appropriate diagnostic and therapeutic approach to patients with human immunodeficiency virus (HIV)-associated lymphoepithelial lesions of the major salivary glands. A retrospective review of 60 consecutive patients with lymphoepithelial lesions is presented. Thirty-eight cases were associated with HIV infection. Lesions associated with HIV infection were usually bilateral, multiple, cystic, and associated with lymphadenopathy. In contrast, in those cases without HIV infection, the lesions tended to be solitary and solid. In the HIV-infected group, treatment included surgery, radiotherapy, zidovudine (AZT), and/or cyst aspiration. All therapeutic regimens, other than aspiration alone, were found to be effective. Eighteen of the patients with HIV infection developed the acquired immunodeficiency syndrome (AIDS) during the study period. Surgical treatment is probably not necessary in the majority of HIV-associated cases. Depending upon individual circumstances, treatment with AZT or low-dose radiotherapy is recommended. A diagnostic and therapeutic algorithm is presented as a guide to the management of future cases.

AIDS-Related Complex↗
PubMed1991

Genetic method to identify regulons controlled by nonessential elements: isolation of a gene dependent on alternate transcription factor sigma B of Bacillus subtilis.

We describe a general, in vivo method for identifying Bacillus subtilis genes controlled by specific, nonessential regulatory factors. We establish the use of this approach by identifying, isolating, and characterizing a gene dependent on sigma B, an alternate transcription factor which is found early in stationary phase but which is not essential for sporulation. The method relies on two features: (i) a plate transformation technique to introduce a null mutation into the regulatory gene of interest and (ii) random transcriptional fusions to a reporter gene to monitor gene expression in the presence and absence of a functional regulatory product. We applied this genetic approach to isolate genes comprising the sigma B regulon. We screened a random Tn917lacZ library for fusions that required an intact sigma B structural gene (sigB) for greatest expression, converting the library strains from wild-type sigB+ to sigB delta::cat directly on plates selective for chloramphenicol resistance. We isolated one such fusion, csbA::Tn917lacZ (csb for controlled by sigma B), which mapped between hisA and degSU on the B. subtilis chromosome. We cloned the region surrounding the insertion, identified the csbA reading frame containing the transposon, and found that this frame encoded a predicted 76-residue product which was extremely hydrophobic and highly basic. Primer extension and promoter activity experiments identified a sigma B-dependent promoter 83 bp upstream of the csbA coding sequence. A weaker, tandem, sigma A-like promoter was likewise identified 28 bp upstream of csbA. The csbA fusion was maximally expressed during early stationary phase in cells grown in Luria broth containing 5% glucose and 0.2% glutamine. This timing of expression and medium dependence were very similar to those for ctc, the only other recognized gene dependent on sigma B.

Amino Acid Sequence↗
PubMed1991

On public sector psychosocial nursing: a conceptual framework.

1. Nursing practice is driven more by its environment than by knowledge provided by faculty or even strong relationships between faculty and staff. Because that environment is publicly supported, programs reflect changes in the ideological environment. 2. The psychosocial nursing specialty incorporates psychiatric/mental health nursing and social sciences to reduce the negative environmental influences while increasing the positive ones. 3. Public sector psychosocial nurses must be familiar with changing laws and regulations as well as the history of hospital and community programs for the mentally ill; understand the complexity of society and that the state hospital is only one component of a large system; and contribute to the development of their subspecialty.

Health Facility Environment↗
PubMed1990

Intrahospital relocation of psychiatric patients and effects on aggression.

Aggression is a recurring problem with psychiatric patients and can pose special problems on inpatient units. The purpose of this study were to identify changes in patients aggression as a consequence of routine individual relocation and to identify the relationship of certain variables with patterns of aggression. Using an adaptation of the Overt Aggression Scale (Yudofsky, Silver, Jackson, Endicott, & Williams, 1986), data were collected from the patient records of 201 individuals who had been admitted to a state hospital and subsequently transferred to another ward in the same hospital. There was a phase by day interaction with the day-to-day pattern of aggression in the pretransfer phase differing significantly from that in the posttransfer phase. The highest mean aggression for a single day was the day following transfer; the second highest was the day before transfer. There were main effects for age and number of hospital admissions.

Adult↗
PubMed1990

Forced relocation of hospitalized psychiatric patients.

By virtue of their disability and hospital program requirements, severely and chronically mentally ill patients are subject to involuntary transfer from the community to hospitals, within hospitals, between hospitals, and from hospitals to the community. These forced relocations, no matter how humanely they were initially conceived to be, have become highly routine. The consequence is loss of the sense of the patient as a human being with individual needs. This research elicited the patients' own descriptions and the meanings they attached to the experience of forced relocation. The findings point to the need for greater success of programs designed to keep patients in their home communities to the greatest extent possible. The findings also suggest the need for hospital staff to eliminate or reduce intrahospital transfers and to develop and maintain humane transfer procedures when forced relocation becomes necessary.

Adult↗