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T Burks

Publications and source records attributed to T Burks.

5 recordsLinked to original sources

Tissue classification with generalized spectrum parameters.

This paper presents performance comparisons between breast tumor classifiers based on parameters from a conventional texture analysis (CTA) and the generalized spectrum (GS). The computations of GS-based parameters from radiofrequency (RF) ultrasonic scans and their relationship to underlying scatterer properties are described. Clinical experiments demonstrate classifier performances using 22 benign and 24 malignant breast mass regions taken from 40 patients. Linear classifiers based on parameters from the front edge, back edge and interior tumor regions are examined. Results show significantly better performances for GS-based classifiers, with improvements in empirical receiver operating characteristic (ROC) areas of greater than 10%. The ROC curves show GS-based classifiers achieving a 90% sensitivity level at 50% specificity when applied to the back-edge tumor regions, an 80% sensitivity level at 65% specificity when applied to the front-edge tumor regions, and a 100% sensitivity level at 45% specificity when applied to the interior tumor regions.

Breast Neoplasms↗

Biomedical research leaders: report on needs, opportunities, difficulties, education and training, and evaluation.

The National Association of Physicians for the Environment (NAPE) has assumed a leadership role in protecting environmental health in recent years. The Committee of Biomedical Research Leaders was convened at the recent NAPE Leadership Conference: Biomedical Research and the Environment held on 1--2 November 1999, at the National Institutes of Health, Bethesda, Maryland. This report summarizes the discussion of the committee and its recommendations. The charge to the committee was to raise and address issues that will promote and sustain environmental health, safety, and energy efficiency within the biomedical community. Leaders from every important research sector (industry laboratories, academic health centers and institutes, hospitals and care facilities, Federal laboratories, and community-based research facilities) were gathered in this committee to discuss issues relevant to promoting environmental health. The conference and this report focus on the themes of environmental stewardship, sustainable development and "best greening practices." Environmental stewardship, an emerging theme within and outside the biomedical community, symbolizes the effort to provide an integrated, synthesized, and concerted effort to protect the health of the environment in both the present and the future. The primary goal established by the committee is to promote environmentally responsible leadership in the biomedical research community. Key outcomes of the committee's discussion and deliberation were a) the need for a central organization to evaluate, promote, and oversee efforts in environmental stewardship; and b) immediate need to facilitate efficient information transfer relevant to protecting the global environment through a database/clearinghouse. Means to fulfill these needs are discussed in this report.

Biomedical Technology↗

Multiple opioid receptors.

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3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

Precipitation of spinally mediated withdrawal signs by intrathecal administration of naloxone and the mu-receptor antagonist CTP in morphine-dependent mice.

We evaluated the ability of naloxone and the mu receptor antagonist CTP (D-Phe-Cys-Tyr-D-Trp-Lys-Thr-Pen-Thr-NH2) to precipitate withdrawal in morphine-dependent mice after intrathecal (i.t.) administration. The withdrawal syndromes elicited by naloxone and CTP given i.t. were compared to those of CTP or naloxone injected intracerebroventricularly (i.c.v.). When given i.t. or i.c.v., naloxone produced the classical syndrome of events including jumping, wet dog shakes, urination, defecation followed by diarrhea, and weight loss. There was no significant difference in the potency or efficacy of naloxone when it was given i.t. or i.c.v. The profile of withdrawal effects produced by i.t. CTP resembled that caused by i.c.v. CTP; both were different from that of naloxone. The withdrawal signs seen following both i.t. or i.c.v. CTP included wet dog shakes and defecation. Mice treated with i.t. CTP lost significantly less body weight than those treated with i.c.v. CTP. In addition, i.t. and i.c.v. CTP did not stimulate jumping behaviors or diarrhea. In contrast, while i.c.v. CTP resulted in increased incidence of urination, CTP given i.t. did not. These finding indicate that naloxone given spinally acts on mu receptors to precipitate wet dog shaking and defecation, but acts on other non-mu opioid receptors (i.e. delta and/or kappa) to cause jumping, urination, diarrhea and weight loss. The differential effects of CTP given i.c.v. or i.t. suggest that supraspinal mu receptors are more involved in gastrointestinal and urinary bladder function during dependence/withdrawal than their spinal counterparts.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗