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Biomedical subjects

R Woodburn

Publications and source records attributed to R Woodburn.

10 recordsLinked to original sources
PubMed2000

Gamma knife radiosurgery as a primary treatment for prolactinomas.

OBJECT: The purpose of this study was to estimate the efficacy of gamma knife radiosurgery (GKS) in controlling tumor growth and endocrinopathy associated with prolactinomas. METHODS: Between 1993 and 1997, 164 of 469 patients with pituitary adenomas treated by GKS harbored prolactinomas. The dose to the tumor margin ranged from 9 to 35 Gy (mean 31.2 Gy), and the visual pathways were exposed to a dose of less than 10 Gy. The mean tumor diameter was 13.4 mm. The mean follow-up time for 128 cases was 33.2 months (range 6-72 months). Tumor control was observed in all but two patients who underwent surgery 18 and 36 months, respectively, after GKS. Clinical cure was achieved in 67 cases. Clinical improvement was noted with a decrease in the hyperprolactinemia after GKS. Nonetheless, in 31 (29%) of 108 patients who were followed for more than 2 years no improvement in serum prolactin levels was demonstrated, although this could be normalized by bromocriptine administration after treatment. Nine infertile women became pregnant 2 to 13 months after GKS and all gave birth to normal children. There was no visual deterioration related to GKS. Five women experienced premature menopause. In these patients there was subtotal disappearance of the tumor and an empty sella developed. CONCLUSIONS: Gamma knife radiosurgery as a primary treatment for prolactinomas can be safe and effective both for controlling tumor growth and for normalization of prolactin hypersecretion. A higher margin dose (> or = 30 Gy) seemed to be associated with a better clinical outcome. Gamma knife radiosurgery may make prolactinomas more sensitive to the bromocriptine.

Humans↗
PubMed1998

New techniques in the radiotherapeutic treatment of gynecological malignancies.

The management of patients with gynecological malignancies serves as a prominent example of the importance of multi-modality oncologic therapy. Optimal treatment of these patients requires the skillful implementation of surgery, radiation therapy and chemotherapy. The decision to use simple versus combined modality therapy is crucial and best carried out in centers in which an experienced and coordinated multidisciplinary team is available. In this article, we have reviewed the most recent data regarding the role of radiation therapy in gynecological malignancies and have pointed out those areas where additional confirmatory studies are needed.

Antineoplastic Agents↗
PubMed1997

Advances in gynecologic radiation oncology.

Radiation therapy is an important modality in the curative and palliative management of patients with gynecologic malignancies. However, the specific roles of radiation therapy continue to evolve in terms of specific indications, volumes treated, techniques, and integration with other modalities. Retrospective assessments of outcome and prospective clinical trials are necessary to answer questions, generate additional hypotheses, and guide further refinements in the application of radiation therapy. This article focuses on recent literature and ongoing clinical trials in this disease group.

Antineoplastic Agents↗
PubMed1993

The A-1 antigen: a novel marker in experimental peripheral nerve injury.

Expression of the Schwann cell phenotype is regulated by signals from the adjoining axon. After axotomy, the Schwann cell ceases the production and maintenance of the myelin sheath and assumes phagocytic properties necessary to digest its own myelin. The molecular mechanisms responsible for this behavior remain unclear. A monoclonal antibody termed BIKS was produced after the immunization of mice with guinea pig lymphoid tissue. This antibody recognizes a cytoplasmic vesicle-associated molecule (A-1 antigen) which is abundant in all tissue macrophages but is also expressed in small amounts in normal Schwann cells. Following axotomy, the A-1 antigen appears to be translocated from a perinuclear site to accumulate in large quantities around myelin ovoids in Schwann cells, as well at the nodes of Ranvier-sites where Wallerian degeneration is known to commence. The level of the antigen remains high when axons are prevented from regeneration. During repair of crush injury, however, the level of antigen drops concomitant with the ingrowth of regenerating axons, suggesting axonal control of A-1 antigen expression.

Animals↗
PubMed1988

A prospective randomized trial of fluorouracil versus fluorouracil plus cisplatin in the treatment of metastatic colorectal cancer: a Hoosier Oncology Group trial.

From May 1984 through December 1986, 141 patients with metastatic adenocarcinoma of the colon or rectum were entered on this Hoosier Oncology Group (HOG) trial evaluating the role of cisplatin in systemic therapy. Patients were stratified by the presence or absence of hepatic metastases and by performance status, and were subsequently randomized to receive fluorouracil (5-FU) (15 mg/kg/wk) alone or the same dose of 5-FU plus cisplatin (60 mg/m2 every 3 weeks). The total duration of treatment was six cycles (18 weeks). In 132 fully evaluable patients the objective response rates were 19% for 5-FU and 22% for 5-FU plus cisplatin. Statistically, the median survival times of 40 and 39 weeks were not significantly different (P = .62). However, the median duration of remission (MDR) was superior (P = .05) for 5-FU alone. This study fails to confirm clinically significant synergy of 5-FU plus cisplatin in the treatment of metastatic colorectal cancer.

Adult↗
PubMed1986

Random prospective study of vindesine versus vindesine plus high-dose cisplatin versus vindesine plus cisplatin plus mitomycin C in advanced non-small-cell lung cancer.

In this phase III randomized study, 124 evaluable patients with unresectable non-small-cell lung cancer (NSCLC) were randomized to vindesine v cisplatin (120 mg/m2) plus vindesine v cisplatin (60 mg/m2) plus vindesine plus mitomycin C. The objective response rate for cisplatin and vindesine was 27% v 20% for cisplatin, vindesine, and mitomycin C, and 14% for vindesine alone (P = .25 for cisplatin and vindesine v vindesine). The percentage of patients having stable disease (no progression for a minimum of 3 months) was 20% (cisplatin and vindesine), 27% (cisplatin, vindesine, and mitomycin C), and 26% (vindesine alone), respectively. The median survival time for vindesine was 18 weeks, compared with 26 weeks for cisplatin and vindesine and 17 weeks for cisplatin, vindesine, and mitomycin C. Overall survival was not statistically different for cisplatin plus vindesine v vindesine (P = .65). There was no evidence for improved duration of remission or survival of responders with the cisplatin (120 mg/m2) and vindesine arm. This study failed to demonstrate sufficient therapeutic benefit for cisplatin and vindesine (+/- mitomycin C) compared with single-agent vindesine to justify the increased cost and toxicity of these combination regimens.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

The prospects for analogue neural VLSI.

In recent years, the efforts of analogue, neural-hardware designers have shifted from generic analogue neurocomputers to "niche" markets in sensor fusion and robotics, and we explain why this is so. We describe the main differences between digital and analogue computation, and consider the advantages of pure analogue and pulsed methods of design. We then investigate some important issues in analogue design of neural machines, namely weight storage (volatile and non-volatile), on-chip learning, and arithmetic accuracy and its relationship to noise. Finally, we outline those areas in which analogue techniques are likely to prove most useful, and speculate as to their likely long-term utility.

Computers, Analog↗