Biomedical subjects
G M Thomas
Publications and source records attributed to G M Thomas.
Design and testing of some automatic sample introduction valves for liquid chromatographs.
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A nucleopolyhedrosis virus in populations of the Douglas-fir tussock moth, Hemerocampa pseudotsugata, in California.
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Significance of Achromobacter nematophilus Poinar and Thomas (Achromobacteraceae: Eubacteriales) in the development of the nematode, DD-136 (Neoaplectana sp. Steinernematidae).
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MR evaluation of cervical cancer in hysterectomy specimens: correlation of quantitative T2 measurement and histology.
Specimens from modified radical hysterectomies performed for invasive carcinoma of the cervix were analyzed with quantitative T2 magnetic resonance (MR) imaging and histologic study to determine to what degree there was a correlation between the findings of the two modalities. The mean T2 of cervical stroma was 48 msec, while the outer zone of the cervix had a mean T2 of 62 msec and the central canal region typically had T2 values of 115 msec +/- 20 (standard deviation). A total of nine cervical cancers were analyzed, and their mean T2 value was 79 msec. Separation between cervical stroma and tumor was good, with stromal T2 values ranging from 30 to 66 msec, while tumor T2s ranged from 60 to 97 msec. Statistical analysis indicated that these data were associated with a sensitivity of 89% and a specificity of 95%, with 95% confidence intervals of [50%, 99.4%] and [74%, 99.7%], respectively, for separating tumor from stroma on the basis of T2 value. Quantitative T2 imaging was found to provide an effective, nonsubjective means of classifying cervical anatomy and neoplastic disease.
Role of radiotherapy in the treatment of cancer of the ovary.
The initial management of carcinoma of the ovary is surgical. The need for further treatment is determined by a consideration of tumor stage, grade, and the presence of residual disease. Approximately one-third of patients are suitably managed by primary post-operative radiotherapy directed to the entire abdomen and pelvis with curative intent. Patients are mainly derived from stages I and II. Stage III patients are also included if the tumor is of low grade and there is no pelvic residuum. The dose which can be safely delivered to the upper abdomen is limited by normal tissue tolerance. Curative radiation is inappropriate for patients with upper abdominal disease and/or more than small volume residuum in the pelvis. These patients are best managed with chemotherapy. Suitably selected patients have a ten-year relapse-free survival of 68% following radiotherapy. Acute gastrointestinal symptoms are common during the treatment, but are usually amenable to symptomatic management. Long term morbidity is infrequent, and with modern techniques the incidence of treatment-related small bowel obstruction is around 5%. Radiotherapy to the abdomen and pelvis has also a potential role as consolidative treatment in patients with advanced disease, following a favourable response to chemotherapy.
Primary radiation therapy in the treatment of anal canal carcinoma.
A retrospective analysis was undertaken of 51 patients with primary anal canal carcinoma who were treated by radiation therapy, with surgery being reserved for those with residual carcinoma. The five-year uncorrected survival rate was 59 per cent, and the corrected survival rate was 71 per cent. The primary tumor was controlled by radiation alone in 29 of 51 patients (57 per cent) and by subsequent radical surgery in eight of ten patients. Abnormal lymph nodes were controlled by radiation alone in eight of 11 patients. Only three of 29 patients required surgery for complications associated with radiation in the absence of persistent tumor. Seventy-seven per cent (23 of 30) of long-term survivors did not require colostomy and retained anal continence. It is concluded that modern radiation therapy techniques are well tolerated and are an effective method of treating carcinoma of the anal canal.
Neurotoxic radiosensitizers and head and neck cancer patients--how many will benefit?
The causes for the exclusion of patients from a Phase I dose tolerance study of metronidazole as a hypoxic cell sensitizing agent in patients receiving radiation therapy for head and neck cancer have been reviewed. One hundred and fifty nine consecutive patients were assessed between October 1979 and December 1980 according to eligibility criteria decided upon prior to the study. Only 26 (23%) of 111 patients treated with radical radiation therapy entered the Phase I study. The major reasons for exclusion were a history of prior nervous system abnormality, age over 70, and refusal by some patients to participate in the study. The criteria used for patient selection for studies of hypoxic cell sensitizers (and other investigational agents) must be known so that data from each study can be assessed appropriately before being extrapolated to the general patient population. Clinical trials should be designed to take into account factors that might influence patient entry.
Postoperative concurrent chronomodulated 5-fluorouracil/leucovorin infusion and pelvic radiotherapy for squamous cell carcinoma of the ovary arising from mature cystic teratoma.
Primary squamous cell carcinoma (SCC) of the ovary arising from mature cystic teratoma (MCT) is rare. Survival is very poor. Although different postoperative treatments have been tried, none appears to have influenced outcomes. A 44-year-old patient with FIGO stage IIB SCC of the ovary arising in MCT had exploratory laparotomy and left salpingo-oophorectomy, leaving macroscopic residual pelvic disease. Postoperative treatment consisted of a continuous concurrent chronomodulated infusion of 5-fluorouracil 150 mg/m2/day and leucovorin 10 mg/m2/day with 5 weeks of pelvic radiotherapy. Three years after initial surgery, she remains disease and complication free. Given this patient's unusually long disease-free survival and the efficacy of concurrent chemotherapy and radiotherapy in other SCCs, the concurrent circadian treatment approach used for this patient should be explored in other cases of SCC of the ovary.
An improved needle adaptor for central venous catheters.
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The first reported case of Aerococcus bacteremia in a patient with HIV infection.
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Nursing in Lebanon.
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