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Biomedical subjects

G Owens

Publications and source records attributed to G Owens.

At least 37 records · Page 2Linked to original sources

Mechanisms of injury in unilateral testis torsion.

We investigated the mechanisms of injury involved in unilateral testis torsion as well as the interventional effects of orchiectomy at 48 h and immunosuppression with corticosteroids in rats. Torsion was associated with abnormal contralateral testis histology and raised antilymphocytes and antisperm antibody titers. Both orchiectomy and steroid administration lessened these findings, suggesting that an immunological process underlies the abnormality seen in this experiment model.

Animals↗

Randomized comparisons of radiotherapy and nitrosoureas for the treatment of malignant glioma after surgery.

Within three weeks of definitive surgical intervention, 467 patients with histologically proved malignant glioma were randomized to receive one of four treatment regimens: semustine (MeCCNU), radiotherapy, carmustine (BCNU) plus radiotherapy, or semustine plus radiotherapy. We analyzed the data for the total randomized population and for the 358 patients in whom the initial protocol specifications were met (the valid study group). Observed toxicity included acceptable skin reactions secondary to radiotherapy and reversible leukopenia and thrombocytopenia due to chemotherapy. Radiotherapy used alone or in combination with a nitrosourea significantly improved survival in comparison with semustine alone. The group receiving carmustine plus radiotherapy had the best survival, but the difference in survival between the groups receiving carmustine plus radiotherapy and semustine plus radiotherapy was not statistically significant. The combination of carmustine plus radiotherapy produced a modest benefit in long-term (18-month) survival as compared with radiotherapy alone, although the difference between survival curves was not significiant at the 0.05 level. This study suggests that it is best to use radiotherapy in the post-surgical treatment of malignant glioma and to continue the search for an effective chemotherapeutic regimen to use in addition to radiotherapy.

Aged↗

Pathologic flail chest complicating multiple myeloma.

Pathologic flail chest complicated the initial presentation of multiple myeloma in two patients. Both had severe hypercalcemia and diffuse bone disease. Atelectasis and pulmonary edema preceded the appearance of flail chest in one patient; atelectasis complicated the flail chest in the second patient and increased the severity of the flail. Both were treated with radiotherapy and chemotherapy. However, delay in stabilizing the first patient's chest wall with positive airway pressure was followed by extension of the flail chest and irreversible respiratory failure. On the other hand, prolonged stabilization of the chest wall in the second patient until a chemotherapy-induced remission occurred was associated with resolution of the flail chest.

Bone Neoplasms↗

Evaluation of BCNU and/or radiotherapy in the treatment of anaplastic gliomas. A cooperative clinical trial.

A controlled, prospective, randomized study evaluated the use of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and/or radiotherapy in the treatment of patients who were operated on and had histological confirmation of anaplastic glioma. A total of 303 patients were randomized into this study, of whom 222 (73%) were within the Valid Study Group (VSG), having met the protocol criteria of neuropathology, corticosteroid control, and therapeutic approach. Patients were divided into four random groups, and received BCNU (80 mg/sq m/day on 3 successive days every 6 to 8 weeks), and/or radiotherapy (5000 to 6000 rads to the whole brain through bilateral opposing ports), or best conventional care but no chemotherapy or radiotherapy. Analysis was performed on all patients who received any amount of therapy (VSG) and on the Adequately Treated Group (ATG), who had received 5000 or more rads radiotherapy, two or more courses of chemotherapy, and had a minimum survival of 8 or more weeks (the interval that would have been required to have received either the radiotherapy or chemotherapy). Median survival of patients in the VSG was, best conventional care: 14 weeks (ATG: 17.0 weeks); BCNU: 18.5 weeks (ATG: 25.0 weeks); radiotherapy: 35 weeks (ATG: 37.5 weeks); and BCNU plus radiotherapy: 34.5 weeks (ATG: 40.5 weeks). All therapeutic modalities showed some statistical superiority compared to best conventional care. There was no significant difference between the four groups in relation to age distribution, sex, location of tumor, diagnosis, tumor characteristics, signs or symptoms, or the amount of corticosteroid used. An analysis of prognostic factors indicates that the initial performance status (Karnofsky rating), age, the use of only a surgical biopsy, parietal location, the presence of seizures, or the involvement of cranial nerves II, III, IV, and VI are all of significance. Toxicity included acceptable, reversible thrombocytopenia and leukopenia.

Adolescent↗

Evaluation of mithramycin in the treatment of anaplastic gliomas.

A controlled, prospective, randomized study evaluated the use of mithramycin in the treatment of anaplastic glioma compared to a similar group of patients receiving best conventional care. From a total of 116 patients in the study, 96 were within the valid study group. All patients were operated on, had histological confirmation of anaplastic glioma, and received radiotherapy at the discretion of the principal investigator. Fifty-two patients received mithramycin at a dose of 25 mug/kg/day for 21 days, while 44 patients were in the control group. There was no significant difference in the median survival from time of randomization in those receiving mithramycin (21 weeks) as compared to those not receiving mithramycin (26 weeks). There was no significant difference between the two groups in relation to age distribution, sex, location, diagnosis, tumor characteristics, signs or symptoms, or radiotherapy received. Duration of symptoms correlates positively with survival and was also significantly longer in the control group than in the treated group. This, however, did not account for the failure of mithramycin to be found an effective agent. Although the study was not designed to evaluate the efficacy of radiotherapy, patients who were so treated had a significant improvement in survival. The toxic complications of mithramycin included gastrointestinal symptoms, dermatological involvement, anemia, and liver dysfunction, indicating the need for close supervision.

Adult↗

Myocardial perfusion and metabolism at normothermic and hypothermic levels.

Changes in intramyocardial carbon dioxide tension (Pco2) and arterial oxygen tension (Po2) were recorded in dogs with a mass spectrometer after temporary occlusion of the aorta and the proximal part of the anterior descending coronary artery at normothermic and hypothermic levels. Patterns of hypoxic and hypercapnic changes and their recovery were favorably modified with moderate hypothermia. Deep levels of hypothermia seemed to enhance this protective effect and progressively slow the myocardial metabolism. Occlusion of the proximal part of the anterior descending coronary artery for 30 minutes had a regional effect similar to the general myocardial changes recorded after aortic clamping, while the posterior myocardial probe showed stable control values. These data support previous studies showing that moderate hypothermia halves the oxygen consumption and doubles the "safe" period of anoxic arrest.

Animals↗

[Intraocular and cerebral reticular sarcoma].

An anatomo-clinical study is presented of a reticulum cell sarcoma (or lymphosarcoma), limited to the eye-ball and the brain. The eye disease developed as a chronic, diffused hypertensive uveitis. The diagnosis of the nature of the brain tumour was made by cytological study of the cerebro-spinal fluid.

Aged↗