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Biomedical subjects

M Thomas

Publications and source records attributed to M Thomas.

At least 379 records · Page 21Linked to original sources
PubMed1997

The ability of various acetabular components to resist protrusio migration.

A foam model of a protrusio acetabulum with cylindrical voids of varying diameters was used to test acetabular components for their ability to resist migration within the defect. A bipolar component, a hemispherical cup, and a hemispherical cup with peripheral rim augmentation were tested in defects with diameters ranging from 1 to 3 mm less than the major diameter of the component. The cup with peripheral rim augmentation demonstrated 20% to 40% greater resistance to migration than the hemispherical cup, depending on the extent of under-reaming, with the bipolar component consistently demonstrating the lowest load to failure. The results of this study confirm the less-than-satisfactory clinical results seen with bipolar reconstruction of protrusio acetabuli, and support the use of "fixed" cups in these settings.

Acetabulum↗
PubMed1997

Acute transverse myelitis.

Acute transverse myelitis is a relatively uncommon neurological disease in which affected patients exhibit acute dehabilitating symptoms associated with the loss of spinal cord segment function. During January 1996, a 23-year-old black female college student, who had been previously healthy, presented to our clinic with acute onset of symptoms typical of acute transverse myelitis. These symptoms included bilateral lower extremity paresthesias, back pains in the thoracic and lumbar areas and pronounced lower extremity weakness. This article is a review of literature to learn about the presenting symptoms, postulated etiologies, diagnostic studies, laboratory findings, management, and variable prognosis for acute transverse myelitis.

Acute Disease↗
PubMed1997

Botryomycosis.

Explore the source record for details and available documents.

AIDS-Related Opportunistic Infections↗
PubMed1997

Mullerian adenosarcoma of the uterine cervix.

Two cases of mullerian adenosarcoma with heterologous elements which occurred in uterine cervix and had a gross appearance of sarcoma botyroides are reported. Histologically, the tumours were composed of an admixture of benign appearing glands and a sarcomatous stroma, with heterologous elements consisting of skeletal muscle, bone and cartilage. No malignant epithetial components were observed. Indications are that, the prognosis of these tumours are much better than the usual malignant mixed mullerian tumours.

Adenosarcoma↗
PubMed1996

Subnanometer-Diameter Wires Isolated in a Polymer Matrix by Fast Polymerization

The preparation and analysis of inorganic-organic polymer nanocomposites consisting of inorganic nanowires and multiwire "cables" in a random-coil organic polymer host is reported. Dissolution of inorganic (LiMo3Se3)n wires in a strongly coordinating monomer, vinylene carbonate, and the use of a rapid polymerization in the presence of a cross-linking agent produce nanocomposites without phase separation. Polymerization of dilute solutions yields a material containing mostly (Mo3Se3(-))n mono- and biwires, 6 to 20 angstroms in diameter and 50 to 100 nanometers long. Polymerization of more concentrated liquid crystalline solutions yields a nanocomposite containing oriented multiwire cables, 20 to 40 angstroms in diameter and up to 1500 nanometers long, that display optical anisotropy and electrical conductivity.

Journal Article↗
PubMed1996

HPV-18 E6 inhibits p53 DNA binding activity regardless of the oligomeric state of p53 or the exact p53 recognition sequence.

The E6 proteins of the oncogenic-associated human papillomavirus types 16 (HPV-16) and 18 (HPV-18) function by interfering with the normal cell cycle control mechanisms, particularly those controlled by p53. HPV E6 is able to interfere with p53 function by preventing its binding to DNA target sequences and also by labelling p53 for ubiquitin-mediated degradation. We have previously reported that certain p53 mutants, defective in oligomerisation, vary in their susceptibility to E6-directed labelling for ubiquitin-mediated degradation. In this paper we report that the strength of p53's binding to DNA is dependent upon the precise target sequence, but that E6 is able to disrupt each complex. We also report the binding of different oligomeric forms of p53 to different DNA sequences and correlate this with in vivo transcriptional activity and demonstrate the susceptibility of that DNA binding to disruption by E6. Finally we show that the ability of p53 to bind to TBP is a function of its oligomeric state and correlates in part with its ability to transrepress but not with its ability to transactivate.

Animals↗
PubMed1996

Induction of apoptosis by p53 is independent of its oligomeric state and can be abolished by HPV-18 E6 through ubiquitin mediated degradation.

Inhibition of p53 function is a common feature of many DNA tumour viruses. Human papillomavirus (HPV) E6 proteins from the oncogenic HPVs inhibit p53 function either by blocking its ability to bind DNA or by labelling newly synthesised p53 as a target for ubiquitin mediated degradation. In this study we have investigated the role of the degradation function of E6 with respect to p53 function. Using a panel of previously characterised p53 mutant proteins we have been able to establish a series of assays which separates p53 growth suppression from transformation suppression and from induction of apoptosis. Only wild type p53 inhibits the growth of p53 null 10(1) cells, whereas wild type, dimeric and monomeric mutants of p53 suppress transformed cell growth of both Saos-2 cells and baby rat kidney cells. Cells expressing the different oligomeric forms of p53 all retain the ability to induce apoptosis upon u.v. treatment. Using HPV E6 and E7 we have been able to show that E7 will overcome p53 growth suppressor activity with an efficiency similar to that observed with E6. However, in contrast to E6, E7 has no effect on the ability of p53 to suppress transformed cell growth. Finally, we show that the ability of E6 to label p53 for ubiquitin mediated degradation is prerequisite for its ability to overcome p53 inhibition of transformed cell growth and induction of apoptosis. These observations argue that E6 inhibits p53 mediated apoptosis and suppression of transformation while E7 inhibits p53 suppression of cell proliferation.

Animals↗
PubMed1996

Immunophenotyping of lymphocytes obtained by bronchoalveolar lavage: description of an all-purpose tricolor flow cytometric application.

A tricolor flow cytometric application is described which permits the determination of total T lymphocytes, T helper lymphocytes and cytotoxic T lymphocytes, natural killer cells and activated T lymphocytes under the same experimental conditions. Even when the lymphocyte count is low, when there is contamination by dust particles or when the cells are damaged the method works with high specificity and reliability. Lymphocytes are identified on the basis of their expression of the pan-leucocyte marker CD45, their side scatter, and plasma membrane integrity, assessed using the fluorescent DNA dye LDS 751. When lymphocyte subsets assessed by flow cytometry were compared with the standard immunoperoxidase method, a strong correlation was found for the CD3+, CD4+ and CD8+ cells. A weak correlation was found for CD25+ cells (r = 0.5). No correlation was seen for CD56+ cells. The high specificity of the procedure suggests that it could be used routinely for the analysis of lymphocytes in bronchoalveolar lavage fluid (BALF), especially when the BALF is contaminated by inorganic particles. Furthermore the application may contribute to the evaluation of lymphocyte subset analysis in the presence of low cell counts.

Bronchoalveolar Lavage Fluid↗
PubMed1996

[Successful multimodal therapy of a locally advanced non-small-cell bronchial cancer].

HISTORY AND CLINICAL FINDINGS: A chest radiogram, performed on a 60-year-old man with unproductive cough for 3 months, showed a space-occupying lesion in the right upper lobe, and breath sounds were diminished in this area. He had been a heavy smoker. His general condition and nutritional state were good. INVESTIGATIONS: Computed tomography, skeletal scintigraphy, bronchoscopy with biopsy and mediastinoscopy established the diagnosis of a locally advanced non-small-cell bronchial carcinoma (stage IIIB or T2N3M0). TREATMENT AND COURSE: Combined adjuvant treatment was begun in the hope of improving the median survival time of 8 months predicted for this tumour stage. After two cycles of a combined chemotherapy scheme (ifosfamide, carboplatin, etoposide) he received hyperfractionated-accelerated radiotherapy (total dose 45 Gy; 1.5 Gy twice daily) together with carboplatin and vindesine. This was followed by a right upper lobectomy with lymphadenectomy. Full remission was confirmed in both the resected specimen and the lymph nodes. The patients remains free of tumour 30 months after the diagnosis. CONCLUSION: Neoadjuvant treatment can significantly improve the prognosis of non-small-cell bronchial carcinoma in stage III. Such patients should therefore be treated according to the appropriate study protocol, if possible.

Antineoplastic Combined Chemotherapy Protocols↗