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Biomedical subjects

F C Lee

Publications and source records attributed to F C Lee.

At least 55 records · Page 3Linked to original sources
PubMed1980

Hydrolysis of phosphatidylethanolamine induced by nominally synthetic lysophosphoglycerides: methodological implications.

Synthetic lysophosphatidylethanolamine (LPE) obtained from commercial sources augmented the apparent activity of phospholipase A2 (PLA2) in cardiac mitochondrial and microsomal fractions. For elucidation of this phenomenon, 2-[1-14C]linoleylphosphatidylethanolamine was incubated in the absence of cell protein with selected concentrations of LPE, lysophosphatidylcholine (LPC), Ca2+, ionic and nonionic detergents, and phospholipids with functional groups similar to those of LPE. Hydrolysis of phosphatidylethanolamine (PE) was evaluated by measurement of 14C-labeled free fatty acid release and confirmed by quantification of [14C]ethanolamine-labeled LPE formed. The reaction was dependent on the concentrations of Ca2+, PE, and LPE, exceeding 1.5 nmol/h with 20 micro M LPE and 30 micro M PE. Hydrolysis occurred in the presence of as little as 1 micro M LPE. PE was not hydrolyzed by comparable concentrations of ionic or nonionic detergents or by several closely related phosphatides, including LPC. Purification of synthetic LPE by high-performance LC to remove contaminating PLA2 eliminated the effect. LPE-induced hydrolysis of PE was found to depend on contamination of the LPE by PLA2 from Crotalus atrox, employed in the commercial synthesis of the lysophosphatide from the precursor used, phosphatidylethanolamine. Contamination of commercially obtained lysophosphoglycerides by PLA2 constitutes a technical pitfall which may cloud interpretation of experiments performed with inadequately purified material.

Animals↗
PubMed1978

Cardiovascular trauma from angiographic jets--validation of a theoretic concept in dogs.

The relationship of angiographic injections to cardiovascular trauma was determined. The aorta of dogs was studied by a mathematic model that (a) defines the kinetic energy of contrast-media jets emanating from the exit holes of catheters and (b) enables precise correlation of energy levels to potential trauma. A universal curve independent of the Reynolds number of the jet readily determines how far the jet penetrates intravascular blood. A traumatic histopathologic spectrum was found for those injections predicted by the model to be traumatic. The curve enables the angiographer to calculate the safe operating range of any catheter.

Angiography↗
PubMed1978

Cardiac trauma from angiographic injections. A quantitative study.

To relate angiographic injections to potential cardiac trauma, we verified a mathematic theory that allows quantitative definition of the kinetic energy content of contrast jets emanating from the exit holes of angiographic catheters. Cineangiographic recordings of a range of jets of known energy content were obtained in 18 cardiac canine experiments and energy content and dissipation were quantified precisely from center line to jet edge. All contrast jets produced in clinical angiographic practice were turbulent, even those from hand injections into the coronary arteries. Energy content was related to an estimated cardiac wall damage threshold. At energy levels and damage thresholds predicted by the theory and computations, a traumatic spectrum was found by cineradiology and microscopic examination. A unique curve independent of jet Reynolds number was discovered relating the penetration of the contrast jet into the intravascular blood to the potential for cardiac trauma. This curve allowed ready calculation of hydraulic energy dissipation for any clinically used angiographic catheter and the definition of safe operational injection flow rates. Thus potential cardiac trauma can be anticipated and prevented.

Angiography↗
PubMed1977

A quantitative method for determining angiographic jet energy forces and their dissipation: theoretic and practical implications.

Jets emanating from the exit holes of cardiac catheters during angiographic injections are theoretically capable of producing severe localized cardiovascular trauma. We adopted a fluid mechanical model of an axially symmetric jet to define these energy forces quantitatively, especially as they would occur in the clinical setting. During angiographic injection at all catheter flow rates used clinically, the jet emanating from the exit hole was always turbulent. The physical characteristics of the turbulent jet penetration into the intravascular blood fell upon a universal curve independent of the jet Reynolds number. This curve, never previously described, allows ready calculation of hydraulic energy dissipation for any catheter of known length and lumen size. The diameter of the catheter exit orifice has a greater effect than injection flow rate on decreasing jet penetration. These results provide useful guidelines for reducing trauma during routine angiography.

Angiocardiography↗
PubMedDate not supplied

Angiogenesis in gynecological oncology-mechanism of tumor progression and therapeutic targets.

The purpose of this article is to review the current literature pertaining to various angiogenic stimulators and angiogenesis inhibitors in gynecological malignancies and the relevance of these markers in the prognosis of these diseases. We also summarize the antiangiogenic drugs currently in development and in clinical use in gynecological oncology. The information was obtained from a computer search of MEDLINE for studies published in the English language regarding angiogenesis and angiogenesis inhibitors in gynecological malignancies between 1970 and December 2003; additional sources were identified through cross-referencing. In ovarian cancer, various different angiogenic activators have been found to correlate with microvessed density (MVD), stage, lymph node and peritoneal metastasis, and survival. In cervical cancer, correlation has been seen between increased angiogenic markers and stage, grade, tumor size, and survival. Studies in endometriat cancer show correlation of angiogenic markers with stage, grade, MVD, and survival. Whereas, in gestational trophoblastic neoplasm (GTD) only few markers have been studied, and some correlated with progression. Information on anti angiogenic drugs currently in ongoing and upcoming trials in gynecological malignancies is also presented. Angiogenesis factors may have a prognostic role to play in patients with gynecological cancers and should continue to be investigated as clinically useful tumor markers. Antiangiogenic-targeted therapies offer an attractive strategy for clinical investigation in gynecologic oncology.

Animals↗
PubMedDate not supplied

Reengineering managed behavioral healthcare.

Reengineering is an industrial method for rethinking and redesigning basic business processes in order to improve performance and lower cost. Just as many of the corporate clients of managed behavioral healthcare companies go through reengineering initiatives, behavioral healthcare needs to streamline its production processes, in order to deliver services that are high quality but affordable. Traditional, cumbersome, bureaucratic and labor-intensive work processes must be reexamined. This article reviews basic principles of reengineering in the context of the evolving managed behavioral healthcare industry, defines ten core processes for managed behavioral healthcare companies and then illustrates how reengineering methods can be applied to two intermediate processes: "manage access" and "manage network."

Clinical Protocols↗
PubMedDate not supplied

The next generation of managed mental health care.

The rise in mental health claims and the tremendous expansion of psychiatric facilities and services have put payers and providers alike on the defensive. Payers cut benefits, while providers rush to justify even clearly needed care. The venturesome in both camps will be intrigued by General Telephone of California's comprehensive, managed mental health care program, combining the PPO concept with provider risk and strong case management, as described by the authors, Vice Presidents of Preferred Health Care, Ltd.

California↗
PubMedDate not supplied

Emergency department organisation for disasters: a review of emergency department disaster plans in public hospitals of Singapore.

Disaster management plans of emergency departments (EDs) in four major public hospitals were reviewed. A comparison was made between these plans, and they were analyzed to gain an understanding of the differing objectives and doctrines behind the practices. These were summarized into five major management concepts, which are considered to be critical to the success of a disaster plan: 1) staff mobilization systems (cascading vs batch mobilization); 2) staff deployment systems; 3) team organization (surgeons vs residents); 4) area management (the role of the area manager); 5) casualty volume management (accommodation vs expansion vs extension concepts). The concepts derived should serve as a useful guide to the development of an ED disaster plan and potentially influence how new ED facilities could be planned.

Disaster Planning↗