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Biomedical subjects

G M Thomas

Publications and source records attributed to G M Thomas.

At least 91 records · Page 5Linked to original sources
PubMed1983

Radical external beam radiation therapy for adenocarcinoma of the rectum.

External beam megavoltage radiation therapy was used as primary treatment for 123 patients with rectal adenocarcinoma. Surgery was undertaken for some patients who had residual tumor. The overall five-year survival rate was 21 per cent. When patients were separated into those who presented with clinically mobile and those with clinically fixed rectal tumor masses, the survival rates were 38 per cent and 2 per cent, respectively. The primary tumor was controlled by radiation alone in 21 of 56 (38 per cent) patients who had mobile tumors but in only six of 67 (9 per cent) patients who had fixed tumors. Further investigation of high-dose primary radiation, with surgery reserved for patients with residual rectal carcinoma, may allow reduction of the number of patients who require abdominoperineal resection.

Adenocarcinoma↗
PubMed1982

Observer variation in the assessment of patients with rectal cancer.

To examine the reliability of clinical features as possible components of a clinical method of prognostic staging for patients with rectal cancer, the results obtained when two pairs of physicians interviewed and examined a consecutive series of 60 patients with unresected rectal cancer were compared. High levels of agreement between physicians were found for most items of the patient's history, on whether the lesion was palpable, on the distance of the tumor from the anus, on the location and circumferential extent of the tumor, and on whether the tumor was fixed or mobile. Although physicians elicited similar physical signs, their use of terms to describe the rectal lesions varied widely unless agreed-upon criteria were used. There was 63 per cent agreement on the use of descriptive terms among physicians using criteria and only 13 per cent agreement among physicians not using criteria. These results show that prognostically important clinical features in patients with rectal cancer can be reliably identified and are thus suitable for inclusion in methods of clinical prognostic staging for this disease.

Humans↗
PubMed1982

Ram epididymitis: A clinical report.

Two hundred and five ram lambs originating from several sources were assembled for a ram performance trial. All rams were immunized with a commercial Brucella ovis bacterin. Four rams developed clinical evidence of epididymitis during the 150 day trial. Actinobacillus seminis was identified as the causative agent.

Journal Article↗
PubMed1982

Seminoma of the testis: results of treatment and patterns of failure after radiation therapy.

Four hundred and forty-four patients with the histological diagnosis of pure seminoma were treated at The Princess Margaret Hospital between 1958 and 1976. Using the Walter Reed Hospital staging classification, 338 patients (76.1%) were Stage I, 86 (19.4%) were Stage II, and 20 (4.7%) were Stage III. The 5 year actuarial survival rate (5 yr Sa) for all stages was 87%, and for Stages I, II and III: 94%, 74% and 32% respectively. In Stage II the 5-year Sa was significantly worse when palpable abdominal disease was present (62%, vs 87% when it was absent, p less than .02). Prophylactic mediastinal irradiation was not used for patients with Stage II disease. None of 40 Stage II patients without palpable abdominal disease recurred in the non-irradiated mediastinum. Ten of 46 Stage II patients with palpable abdominal disease recurred in the mediastinum; 7 of the 10 were cured with mediastinal irradiation at the time of relapse. Prophylactic mediastinal irradiation appears unnecessary in Stage II patients. The Stage III category includes a subgroup of patients who were curable with radiation therapy:L 5/6 with supradiaphragmatic nodal disease without palpable abdominal or visceral disease were cured. Exploration of new treatment methods appears indicated for the salvage of patients recurring in sites other than the mediastinum or supraclavicular fossa and for patients presenting with visceral disease.

Adolescent↗
PubMed1982

A phase I study of misonidazole and pelvic irradiation in patients with carcinoma of cervix.

A Phase I study of oral daily misonidazole (MISO) with conventional pelvic irradiation, has been conducted in patients with carcinoma of the cervix Stages IB, IIB, IIIB and IVA. MISO was administered in daily dosages to sequential groups of patients at doses of 0.15 g/m2, 0.30 g/m2 or 0.45 g/m2 for 22 days over 5 weeks. Sixteen patients were assigned to each dose level. Using a double-blind randomization, they received either placebo (3/16) or MISO (13/16). The major dose-limiting toxicity was peripheral neuropathy (PN). None of the 13 patients receiving 0.15 g/m2 or the 13 receiving 0.3 g/m2 developed PN. However, 6/13 at the 0.45 g/m2 level (total dose less than or equal to 9.9 g/m2) developed PN. Additional patients were entered at this level and a total of 13/26 developed PN, which was considered of clinically significant severity in 9. Symptoms of PN have persisted from 1 week to 10 months, and have been completely reversed in 9/13 patients. Pharmacological parameters were examined for correlation with clinically evident toxicities. Although peak plasma MISO levels and half-lives did not correlate significantly with PN, there was a significant correlation between the calculated "area under the curve" (AUC) and PN. No correlation exists between PN and total urinary excretion of MISO or the O-demethylation product. A daily dose of 0.45 g/m2; MISO (total dose less than or equal to 9.9 g/m2) is considered to produce an acceptable level of toxicity for this patient population.

Double-Blind Method↗
PubMed1982

Combined radical radiation therapy and chemotherapy for primary squamous cell carcinoma of the anal canal.

Radical radiation therapy (5000 rads in 20 fractions in 4 weeks) combined with iv mitomycin (10 mg/m2) and 5-FU (1000 mg/m2/24 hours for 4 days) was used to treat 13 patients with locally advanced but operable squamous cell carcinoma of the anal canal. All patients achieved local control and retained anal continence, and none developed metastases. The patients were followed from 4 to 34 months (median, 12). Severe acute gastrointestinal toxic effects were seen in three patients; the same patients had significant thrombocytopenia or leukopenia. Treatment with this combined program may allow conservative management of squamous cell carcinoma of the anal canal and should be considered as an alternative to abdominoperineal resection.

Adult↗
PubMed1981

Brucellosis in elk III. Serologic evaluation.

The efficacy of the standard plate agglutination (SPT), buffered Brucella antigen rapid card (BBA), rivanol (Riv) and complement fixation (CFT) tests was statistically evaluated and correlated with known brucellosis infections in elk. Low titers on the SPT were detected in artificially exposed mature cow elk 2 weeks postinoculation and other tests began detecting antibodies at 3 weeks. Titers on all tests were detected as long as 4 years postinoculation. Serologic response was similar in artificially and naturally infected cows. Bulls did not maintain serologic titers as long as cows. The SPT at 1:25 or higher most frequently detected Brucella antibodies in infected elk, while the SPT at 1:100 or more least frequently detected antibodies. The percent of elk reacting at 1:100 or greater on the SPT declined rapidly after 6 months postinoculation. Combinations of any 2 of the 4 tests used had close agreement in concurrently identifying infected elk. The CFT correctly identified the greatest number (93%) of elk which were culture positive at necropsy and CFT titers persisted longer than those of the other tests. A CFT reaction persisted longer (average 10.7 weeks) than that of any other test in calves that demonstrated postnatal titers. The serologic responses of calves which acquired active infections were similar to adults. Criteria for identifying seropositive elk are discussed.

Agglutination Tests↗
PubMed1981

Further studies on trypanosomes in game animals in Wyoming II.

Further studies on moose revealed trypanosomes in two captive moose (Alces alces shirasi) and in 4 of 7 free-ranging moose in Wyoming by blood culture. Two free-ranging moose from Utah were negative. One of two additional captive moose calves was positive for trypanosomes. Trypanosomes also were detected in blood cultures of 8 of 39 American Bison (Bison bison) being brought into Wyoming from Nebraska. Nineteen additional bison were negative for trypanosomes by blood cultures. Identification of species was not possible due to the failure to obtain bloodstream trypomastigotes from this host. Trypanosomes were recovered from 8 of 57 pronghorn antelope (Antilocapra americana). This is the first report of Trypanosoma sp. from bison and from pronghorn; the trypanosome from moose was identified as Trypanosoma cervi from bloodstream trypomastigotes. In 1978, natural transplacental transmission of trypanosomes was found to occur in 1 of 15 mule deer (Odocoileus hemionus) fetuses, examined near term by blood culture. No trypanosomes were found in 18 male deer fetuses examined in 1979. Of 100 free-ranging elk from western Wyoming examined by blood culture in 1979, 71 were infected. These data are compared with data from 1973-74.

Animals↗
PubMed1981

Testicular tumours in maldescended testes.

Maldescent is known to increase the risk of cancer of the testis. However, the effect of orchiopexy on reducing tumour risk and altering tumour type or stage at diagnosis is not established. The authors review the records of patients with testicular tumours seen for seminoma (1958 to 1975) and nonseminoma (1958 to 1970). Of 646 patients, 53 (8.2%) had a history of testicular maldescent; in 42 (79%) the maldescent was unilateral and in 6 of these, the tumour developed in the normally descended testis. Twenty patients had successful orchiopexy at a median age of 14 years (range from 6 to 35 years). Tumours found in the 53 patients were seminoma (38 patients), teratoma (7 patients), embryonal carcinoma (6 patients), teratocarcinoma (1 patient) and choriocarcinoma (1 patient). Average age at the time of diagnosis of seminoma was 38 years and of nonseminoma 31 years. Average age was lower at the time of diagnosis of the tumour for those who had successful orchiopexy than for those who did not. Earlier stage nonseminomas were found in patients who had an orchiopexy. Twenty-five (66%) of the 38 seminomas occurred in testes located outside the scrotum, whereas only 6 (40%) of 15 nonseminomas occurred in a nonscotal position, suggesting that persistent maldescent favours seminoma over nonseminoma. In this retrospective review, no statement can be made about the effect of orchiopexy on tumour risk. However, this procedure appears to lead to an earlier diagnosis and may influence the type of tumour that subsequently develops.

Adolescent↗
PubMed1980

Combined treatment of squamous cell carcinoma of the anal canal: radical radiation therapy with 5-fluorouracil and mitomycin-C, a preliminary report.

Radical radiation therapy combined with 5-fluorouracil and mitomycin-C was studied in six patients with previously untreated operable squamous cell carcinoma of the anal canal. All six patients achieved local tumor control and have retained anal continence. There has been no evidence of late recurrence to date. This preliminary report demonstrates that this method of treatment warrants further study.

Adult↗
PubMed1979

Testicular degeneration and libido loss in beef bulls experimentally inoculated with Anaplasma marginale.

Four sexually mature virgin beef bulls were inoculated with whole blood from a known Anaplasma marginale carrier. All four bulls became infected and experienced some degree of anemia and testicular degeneration, while uninoculated controls remained normal. Testicular degeneration was confirmed by electron microscopy, histopathology, and semen evaluation. Further observations established that the inoculated bulls exhibited a loss of libido, while controls reacted in a normal manner to a cow in estrus. Anaplasma marginale was not present in semen of inoculated bulls.

Journal Article↗
PubMed1978

Brucellosis in elk I. Serologic and bacteriologic survey in Wyoming.

Incidence of brucellosis in elk (Cervus canadensis) on two winter feedgrounds in Wyoming was examined over a 5-year period by testing serum samples using the standard plate agglutination (SPT) buffered Brucella antigen (BBA), rivanol (Riv) and complement fixation (CFT) tests. Thirty-one percent of 1,165 elk were positive by defined criteria. Considering each test individually, only 29% (106) of 370 positive sera would have been classified as reactors by the SPT, 83% (307) by the BBA test and 86% (314) by the Riv test. The CFT would have identified 85% (267) of 332 positive samples on which it was used. Brucella abortus, type 1, was isolated from 17 of 45 elk necropsied. The SPT identified 59% (10) of these as reactors, the BBA test 94% (16) and the Riv test 88% (15). The CFT identified nine of nine (100%) on which it was used. Prevalence of sero-positive animals increased with age. Brucellosis has been present in one of the two elk herds since at least 1930, and the incidence of infection among mature females in both herds was approximately 50% during this study. No single serologic test should be relied upon to diagnose brucellosis in elk.

Animals↗
PubMed1975

Simultaneous pharmacokinetics of benorylate in plasma and synovial fluid of patients with rheumatoid arthritis.

Twenty patients with definite or classical rheumatoid arthritis and chronic knee effusions were each given an oral dose of 4 g benorylate as the 40% suspension. Synovial fluid and plasma samples were obtained up to 9 hours after drug administration and assayed for their salicylate and benorylate content. A mean peak benorylate plasma level of 2.18 +/- 0.19 mug/ml occurred 30 min after drug administration but declined rapidly and benorylate was virtually undetectable in the plasma 90 min later. The mean peak benorylate synovial fluid level of 0.74 +/- 0.21 mug/ml occurred 3 hours after drug administration but the concentration remained steady for at least a further 9 hours. A mean peak plasma salicylate level of 119 +/- 14.2 mug/ml and mean peak synovial fluid salicylate level of 78 +/- 13.6 mug/ml occurred 3 hours after benorylate administration. Both levels declined slowly over some hours. This study shows that benorylate per se readily enters the synovial fluid in patients with rheumatoid arthritis and continues to accumulate there even when undetectable in the plasma. It is possible that the lipophilic nature of the benorylate molecule facilitates its uptake by the inflamed synovial tissue.

Arthritis, Rheumatoid↗