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D A Brewer

Publications and source records attributed to D A Brewer.

6 recordsLinked to original sources

Cryosurgical ablation of unresectable hepatic metastases.

BACKGROUND AND OBJECTIVES: Recent advancements in the technology of cryosurgery along with the development and refinement of intraoperative ultrasound have led to a feasible alternative for some patients with unresectable hepatic malignancy. This paper reports our first year's experience with cryosurgical ablation of unresectable hepatic malignancies. METHODS: From May 1996 to July 1997, 12 patients with colorectal hepatic metastases underwent exploration for possible resection and/or cryosurgery. At surgery, three patients had extensive disease and were not candidates for any surgical treatment, three underwent formal right hepatic lobectomy, five underwent a combination of resection and cryoablation, while one underwent cryoablation alone. RESULTS: In the six patients who received cryosurgery, the mean number of metastatic lesions was four (range 1-6). The mean number of lesions frozen was two (range 1-4) with a mean size of 2.5 cm. (range 1-5 cm). There were no intraoperative deaths and no major postoperative complications. All patients were discharged home in stable condition with a mean hospital stay of eight days (range 5-14 days). At a mean follow-up of 17.3 months (range 10-22) three patients were alive with disease and three were disease free. CONCLUSIONS: Cryosurgical ablation is a safe method of treating unresectable hepatic malignancies and it may extend survival in carefully selected patients.

Adenocarcinoma↗

Should relatives of patients with colorectal cancer be screened? A critical review of the literature.

PURPOSE: The objective of our investigation was to attempt to address the controversial issue concerning index screening and surveillance of relatives of patients with colorectal cancer and to identify those areas of research that should be considered in future studies. METHODS: Relevant literature was reviewed concerning the screening of asymptomatic first-degree relatives of patients with colorectal cancer not associated with the rare autosomal dominant inherited colorectal cancer syndromes. RESULTS: The data reviewed suggest that there is an increased risk of colorectal neoplasia in this population and a significantly higher yield of adenomas and carcinomas when colonoscopy is used for index screening. However, significant variability in study design and screening protocols and inconsistencies in data presentation make clinical interpretation and data analysis confusing and difficult. CONCLUSIONS: There is a critical need for standardization in future studies. Furthermore, as there are no studies that document decreased overall mortality from colorectal cancer in first-degree relatives as a result of screening, the decision as to whether to screen this population needs to be based on future prospective controlled trials.

Adenoma↗

Heredity, molecular genetics and colorectal cancer: a review.

It is estimated that the hereditary polyposis and non-polyposis colorectal cancer (CRC) syndromes, which have an autosomal dominant pattern of inheritance, represent less than 10% of the total CRC burden. Thus, more than 90% of all cases of CRC have previously been considered to arise 'sporadically', with no identifiable genetic link. However, recent clinical evidence now suggests that a significant proportion of CRC seen in the general population may involve an inherited genetic susceptibility. Therefore, constructing an accurate family tree on all patients with a family history of CRC is an essential part of identifying families with an increased risk for CRC who could then be offered screening. Also, molecular genetic study of colorectal adenomas and carcinomas has led to a proposed genetic model of colorectal tumorigenesis which involves interactions between oncogenes and tumour suppressor genes. This information has important potential implications for screening, determining prognosis and for providing multiple targets for altering the sequence of malignant transformation.

Colorectal Neoplasms↗

A simulation model for the analysis of Space Station gas-phase trace contaminants.

A simulation model for the analysis of gas-phase trace contaminants in the cabin air of the NASA Space Station Reference Configuration was developed at the NASA Langley Research Center. The model predicts changes in trace contaminant concentrations from both physical and chemical sources an sinks as a function of time. Simulations were performed in which values for relative humidity, temperature radiation intensity, pressure, and initial species concentrations were constrained to values for the parameters measured and modeled in the continental tropics at the Earth's surface. Species concentrations simulated using the model compared favorable with concentrations in the continental tropics which demonstrated that the chemical mechanism in the trace contaminant model approximates changes atmospheric species concentrations. The sensitivity of initial species concentrations to producing change in additional species concentrations was also assessed. Results from the model indicated that chemical reactions will be important in determining the composition of cabin air in the Space Station. It is anticipated that the trace contaminant model will be useful in assessing the impact of experiments a commercial operations on the composition of the cabin air in the Space Station.

Air Pollutants↗