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Biomedical subjects

W McDermott

Publications and source records attributed to W McDermott.

At least 19 recordsLinked to original sources

Hepatic cryosurgery with intraoperative ultrasound monitoring for metastatic colon carcinoma.

We utilized cryosurgery with intraoperative ultrasound (IOUS) monitoring in ten patients to treat multiple unresectable hepatic metastases from colorectal carcinoma. The liver was exposed at laparotomy, and tumors were subjected to three cycles of freezing (eight minutes each) and thawing. Freezing was monitored by IOUS, which visualized frozen tumor as a hyperechoic rim with posterior acoustic shadowing. Frozen normal liver appeared hypoechoic after thawing compared with normal unfrozen liver. There were no significant complications. The follow-up ranged from four months to 17 months (median, 7.5 months). Tumor response was documented by pathologic findings (coagulative necrosis), progressive fall of carcinoembryonic antigen levels, and computed tomographic scan evidence of necrosis and shrinkage of tumor. One patient underwent repeated laparotomy five months after cryosurgery and had the frozen lesions resected; there was no residual tumor. This study establishes the technical feasibility and antitumor response of hepatic cryosurgery and the use of IOUS for precise localization and monitoring of cryoablations.

Adult

Society of Gastrointestinal Radiologists Roscoe E. Miller Award. Monitoring hepatic cryosurgery with sonography.

The intraoperative sonographic appearance of frozen hepatic tumors and frozen normal liver was correlated with the histologic appearance of pathologic specimens from six patients. Frozen tissue was visualized as a hyperechoic rim with posterior acoustic shadowing. Normal liver that was frozen and then thawed appeared hypoechoic when compared with normal unfrozen liver. These findings allowed visualization of the extent of freezing in relation to tumor margins. Pathologically, frozen tumors showed definite evidence of necrosis. Normal liver tissue was extremely sensitive to cold and was completely necrotic after freezing. The sonographic appearance of frozen and thawed liver correlated precisely with the gross morphologic and histologic changes seen in the cryolesion. It appears that intraoperative sonography allows accurate monitoring of hepatic cryosurgery.

Carcinoma

Education and general medical care.

Medical education needs to take into account the features of general medical care. Educators should stress the physician's capacity to come to appropriate decisions in the use of diagnostic tests and in referral and should attempt to inculcate the habit of thoroughness. The economics of present-day medical education may undermine its capacity to educate properly for general medical care. Adequate teaching of the discriminating use of diagnostic and therapeutic methods could be promoted directly through research in medical practice. Such research can be carried out despite economic constraints on research in medical schools if the right thinking is applied to important problems.

Clinical Competence

Intraaterial hepatic infusion and intravenous adriamycin for treatment of hepatocellular carcinoma: a clinical and pharmacology report.

Four patients received intraarterial (ia) hepatic infusion and 10 received intravenous (iv) adriamycin for hepatocellular carcinoma. Four of each group are evaluable. The remaining 6 patients died within 14 days of intravenous therapy and are, therefore, considered nonevaluable. Patients received 2 to 9 courses of adriamycin every 3 weeks. One half of each group of evaluable patients had partial responses (pr). The group had pr for 22.5 weeks (range 8 to 37). The iv group had pr 27.2 weeks (range: 16 to 38.5). Mean survival was 21 weeks for nonresponders, and 43 weeks for responders. Intraarterial infusion did not protect patients from adriamycin toxicity. Cardiac and liver toxicity were not seen, but marrow and gastrointestinal toxicity developed at 1.2 X 10(-7)M adriamycin serum level. Adriamycin disappearance curves after ia and iv therapy were similar for similar bilirubin levels, and prolonged with hyperbilirubinemia. Ascites fluid did not accumulate detectable adriamycin. Pharmacokinetics are described in this report.

Adolescent

Inhibition of ribosomal A site functions by sporangiomycin and micrococcin.

Sporangiomycin and micrococcin inhibit the binding of aminoacyl-transfer ribonucleic acid into the ribosomal A site in intact bacterial protoplasts. They also prevent the assembly of [ribosome-elongation factor G-guanine nucleotide] complexes in vitro and compete with [(35)S]thiostrepton for ribosomal binding sites. We conclude that micrococcin and sporangiomycin block the ribosomal A site in the vicinity of the complex guanosine triphosphatase center and so resemble thiostrepton in their modes of action.

Anti-Bacterial Agents