Membranes of normal hamster lymphocytes and lymphoid cells neoplastically transformed by simian virus 40. I. High-yield purification of plasma membrane fragments.

In this first paper of a series comparing the membranes of normal lymphocyte populations from male outbred Syrian hamsters with those of neoplastic transformants (GD 248) induced by simian virus 40, a method is described for the isolation of representative plasma membrane (PM) fragments from both cell types. Multiple criteria were used to monitor the purity and yield of PM material after cell disruption by nitrogen cavitation and after membrane fractionation by a combination of differential centrifugation and isopyknic ultracentrifugation in dextran density gradients. Lactoperoxidase-catalyzed radioiodination before cell disruption was used as an extrinsic surface marker; Na+,K+-activated ATPase, as well as alkaline phosphatase, was used as intrinsic functional PM markers. The distribution of nuclei, mitochondria, lysosomes, and endoplasmic reticulum (ER) during fractionation was monitored by the measurement of DNA, succinate dehydrogenase and monoamine oxidase, beta-glucuronidase and glucose-6-phosphatase, and NADH:lipoamide oxidoreductase, respectively. According to the three PM markers employed, a 15- to 20-fold purification (over homogenate) and a PM yield of about 65% were obtained for both cell categories, with negligible contamination by DNA, mitochondria, lysosomes, and er. The procedure also allowed recovery of 60% of the mitochondria free of other cell elements.

Membranes of normal hamster lymphocytes and lymphoid cells neoplastically transformed by simian virus 40. II. Plasma membrane proteins analyzed by dodecyl sulfate-polyacrylamide gel electrophoresis and two-dimensional immune electrophoresis.

The plasma membrane proteins of lymphocyte populations from normal outbred Syrian hamsters were compared with those of a neoplastic transformant line (GD 248) induced by simian virus 40. Both quantitative and qualitative differences were observed. Gradient dodecyl sulfate-polyacrylamide gel electrophoresis revealed 12 major protein components in the membranes of both cell populations. Both membrane categories also contained small amounts of immunoglobulin. Compared with the membranes of the reference cell population, GD 248 membranes showed a 60% decrease of approximately 210,000 daltons of glycoprotein; a 10% reduction of about a 48,000-dalton band and virtually complete loss of a 15,000-dalton component concomitant with a 57% increase in a 52,000-dalton band; fusion to two subcomponents (mol wt approximately 250,000 daltons); and emergence of approximately 120,000 and 30,000 daltons glycoproteins. In addition, the relative mobility of an approximately 95,000-dalton component increased by roughly 0.02 U. Crossed immune electrophoresis in Trition X-100 with heterologous antiserum against GD 248 microsomal membranes revealed both a new component with a high level of electrophoretic mobility and intensification and additional heterogeneity in a strongly antigenic component with a low level of electrophoretic mobility. Crossed-line immune electrophoresis indicated that at least two antigens in the membranes of GD 248 cells lacked the membranes of the reference cell population.

Organization of an organ donation network.

The National Organ Donation Network involves numerous organizations and institutions, with the organ procurement agencies playing a key role. Figure 2 depicts the complex structure of the procurement process. There is little consistency in structure among community procurement networks, but there is a strong unified approach to the national sharing of organs and tissues. More regionalization has led to better coordination of all procurement and educational efforts, and the role of the procurement coordinator has evolved into a new health profession.

High blood pressure detection: a new public health measure for the dental profession.

Detection of high blood pressure can be a major public health service contribution by the dental profession. The pioneer program at Fairleigh Dickinson University, in conjunction with the Bergen County Health Department and the Bergen County Dental Society, is encouraging dentists to participate in the National High Blood Pressure Program. Participants are urged to measure the blood pressures of all their adolescent and adult patients and to refer those with sustained elevated readings to their physicians, preferably by the arrangements of appointments.

Organ procurement and transplantation.

The path of successful organ transplants has been sown with considerable ethical, legal, social, and moral dilemmas. Some of these dilemmas have been addressed to the public's satisfaction, but many questions are left to be answered. The possibility of prolonging a life through high-technology medicine such as transplantation and through the use of drugs, treatment, and mechanical devices has become an everyday occurrence. However, the need for organs and tissues has created an environment in which hard choices must be made. We must all be involved in the decision-making process, as these are social issues that are presently faced by acquaintances, our friends, and perhaps by our own families. We as individuals must examine our own values as clearly as we examine those of the caregivers, policy makers, social scientists, and ethicists who influence the direction of medical care. We must be ready to ask the important and necessary questions that will guide and enable us to do "the right thing."

Phronesis, clinical reasoning, and Pellegrino's philosophy of medicine.

In terms of Aristotle's intellectual virtues, the process of clinical reasoning and the discipline of clinical medicine are often construed as techne (art), as episteme (science), or as an amalgam or composite of techne and episteme. Although dimensions of process and discipline are appropriately described in these terms, I argue that phronesis (practical reasoning) provides the most compelling paradigm, particularly of the rationality of the physician's knowing and doing in the clinical encounter with the patient. I anchor this argument, moreover, in Pellegrino's philosophy of medicine as a healing relationship, oriented to the end of a right and good healing action for the individual patient.

Coordination of cardiac transplantation: patient processing and donor organ procurement.

As cardiac transplantation has evolved into a viable therapeutic option for some terminally ill patients with end-stage heart disease, the role of clinical transplant and donor organ procurement coordinators has evolved into a new health profession. These well-trained, highly skilled, and dedicated individual's permeate all levels of the organ transplantation process, providing continuity of care and smoothness to a complicated path of operation.

Interdisciplinary education in clinical ethics: a work in progress.

Clinical decision making and, broadly speaking, patient care are increasingly collaborative endeavors dependent on the integration of the profession-specific knowledge, skills, and perspectives of physicians and nurses. Conflicts over the ethical dimensions of clinical decision making often arise from these differing but complementary perspectives. Neither medical nor nursing education adequately prepares future clinicians for these realities of practice. At Georgetown University, students and faculty in medicine and nursing have developed an interdisciplinary curriculum in clinical ethics. The curriculum will bring together medical students and graduate nursing students with the aim of educating and training them to analyze and resolve dilemmas in clinical ethics critically and collaboratively.