Concepts in service marketing for healthcare professionals.

Patients are becoming increasingly involved in making healthcare choices as their burden of healthcare costs continues to escalate. At the same time, healthcare has entered a tightened market economy. For these reasons, the marketing of healthcare services has become essential for the financial survival of physicians and healthcare organizations. Physicians can successfully use the fundamental service marketing principles proven by other service industries to win patient satisfaction and loyalty and remain competitive in today's market economy. Understanding concepts such as service quality zone of tolerance, levels of consumer satisfaction, the branding of services, patient participation, and service recovery can be useful in achieving these goals.

Sentinel lymph node biopsy as an adjunct to management of histologically difficult to diagnose melanocytic lesions: a proposal.

There is a significant subset of primary cutaneous melanocytic neoplasms that are difficult to diagnose with the use of routine light microscopy. The currently recommended approach in assessing such lesions is to make a histopathologic diagnosis that reflects some uncertainty and then to recommend complete surgical excision. While adequate in many cases, the excision that might be recommended for such a lesion if malignant would be mutilating in many others. To increase the sensitivity of diagnosis and to provide potentially useful prognostic information, we propose that sentinel lymphadenectomy be considered in patients with melanocytic neoplasms of uncertain behavior that are 1.0 mm or more in thickness.

Axillary sentinel lymph node examination in breast carcinoma.

OBJECTIVE: To evaluate whether the type of pathologic examination of breast sentinel nodes (frozen section, step sections, and immunoperoxidase staining) results in different percentages of nodes positive for metastatic disease. DESIGN: Twenty-eight consecutive patients with breast sentinel node biopsies were evaluated by step-sectioning the sentinel node(s) along with performing immunoperoxidase stains for low-molecular-weight cytokeratin and epithelial membrane antigen. SETTING AND PARTICIPANTS: The patients were from a university hospital and large private hospital. MAIN OUTCOME MEASURES: The results of the step sections and immunoperoxidase stains were compared with routine examination, that is, intraoperative frozen section along with a single hematoxylin-eosin slide. RESULTS: Nine cases were positive by routine evaluation, 10 by step sections, and 11 by immunoperoxidase staining. CONCLUSIONS: The large, multi-institutional studies of sentinel node utility must take into account the surgical pathology methods used to evaluate these specimens so that uniform techniques, which reliably predict the status of the axillary nodes, can be instituted at all institutions that use this procedure.

Activation of the epidermal platelet-activating factor receptor results in cytokine and cyclooxygenase-2 biosynthesis.

Recent studies suggest that the lipid mediator platelet-activating factor (PAF) is involved in keratinocyte function and skin inflammation. Indeed, PAF is found in association with inflammatory skin diseases, intradermal injections of PAF induce inflammation, and keratinocytes express functional PAF receptors (PAF-R). One mechanism by which the keratinocyte PAF-R could contribute to epidermal functions and inflammatory states would be through the synthesis of inflammatory regulators, such as PAF, PGs, and cytokines. The ability of the epidermal PAF-R to induce the synthesis of these immunomodulators was tested using a model system created by transduction of the PAF-R-negative human epidermal cell line KB with the PAF-R. Activation of this epidermal PAF-R resulted in arachidonic acid release, and the biosynthesis of PAF and PGE2. In addition, the KB PAF-R triggered increased levels of mRNA and protein for the inducible isozyme of cyclooxygenase (COX-2) as well as IL-6 and IL-8, both of which have been implicated in skin inflammatory processes. Studies with the human keratinocyte-derived epidermal cell line HaCaT revealed that activation of the endogenous PAF-R led to the increased accumulation of COX-2, IL-6, and IL-8 mRNA similar to that seen with the KB PAF-R model system. Finally, treatment of HaCaT keratinocytes with IL-8 resulted in PAF biosynthesis, indicating the existence of a positive feedback loop between IL-8 and PAF in epidermal cells. These studies suggest involvement of PAF and the PAF-R in the epidermal cytokine network.

Expression of the platelet-activating factor receptor results in enhanced ultraviolet B radiation-induced apoptosis in a human epidermal cell line.

Recent studies have demonstrated that ultraviolet B radiation (UVB) damages human keratinocytes in part by inducing oxidative stress and cytokine production. Severe UVB damage to the keratinocyte can also result in apoptosis or programmed cell death. Although the lipid mediator platelet-activating factor (PAF) is synthesized in response to epidermal cell damage and epidermal cells express PAF receptors, it is not known whether PAF is involved in UVB-induced epidermal cell apoptosis. These studies examined the role of the PAF system in UVB-induced epidermal cell apoptosis using a novel model system created by retroviral-mediated transduction of the PAF receptor-negative human epidermal cell line KB with the human PAF receptor (PAF-R). Expression of the PAF-R in KB cells did not affect base-line growth or apoptosis, yet resulted in a decrease in the lag time between treatment of the cells and the induction of apoptosis following irradiation with 400 J/m2 UVB. This effect was inhibited by pretreatment with the PAF-R antagonists WEB 2086 and A-85783, confirming involvement of the PAF-R in this process. At lower doses (100-200 J/m2) of UVB, only KB cells that expressed the PAF-R became apoptotic. Treatment of PAF-R-expressing KB clones with the metabolically stable PAF-R agonist 1-hexadexyl-2-N-methylcarbamoyl-3-glycerophosphocholine (CPAF) alone did not induce apoptosis but augmented the degree of apoptosis observed if CPAF was used in combination with lower doses (200 J/m2) of UVB irradiation. Interestingly, UVB irradiation was found to stimulate PAF synthesis only in PAF-R-expressing KB cell clones. The antioxidants N-acetyl cysteine, 1,1,3,3-tetramethyl-2-thiourea, and vitamin E inhibited both UVB-induced PAF biosynthesis as well as the augmentation of UVB-induced apoptosis in PAF-R-expressing KB clones, suggesting the possibility that UVB stimulates the production of oxidized lipid species with PAF-R agonistic activity in this model system. Thus, these studies indicate that a component of UVB-induced epidermal cell cytotoxicity can be modulated by PAF-R activation through the production of PAF and PAF-like species.

Inorganic Pi increases neuronal survival in the acute early phase following excitotoxic/oxidative insults.

Inorganic phosphate (Pi) plays a vital role in intracellular energy metabolism. Its many effects include stimulation of glucose use, enhancement of high-energy phosphate concentrations, and modulation of cytosolic free [Ca2+]. Cultured fetal rat cortical neurons constitutively import Pi, and cytosolic levels positively correlate with [ATP], [NADPH], and energy charge. In the present study, we demonstrate that the concentration of intracellular Pi is an important determinant of acute neuronal survival after an excitotoxic or oxidative insult to cultured fetal rat cortical neurons. Extracellular Pi dose-dependently enhanced survival of cortical neurons after exposure to NMDA at early (< or = 6 h) time points after termination of the insult. Pi similarly increased neuronal survival after exposure to kainic acid or H2O2. Pi-exposed neurons had higher basal intracellular [Pi], [ATP], and [GSH], and slightly lower cytosolic free [Ca2+], compared with Pi-deprived neurons. Pi-exposed neurons maintained increased [ATP] after exposure to NMDA and displayed reduced formation of reactive oxygen species after exposure to kainic acid or H2O2, compared with Pi-deprived neurons. These findings demonstrate that changes in extracellular and intracellular Pi can affect neuronal survival after excitotoxic or oxidative insults.

Ventricular mitochondrial gene expression during development and following embryonic ethanol exposure.

The effects of chronic embryonic ethanol exposure were evaluated in chick ventricular muscle. Ethanol treatments were administered on embryonic days 11, 13, 15, and 17 and chicks were sacrificed at various time points following treatments. Fluctuations in embryonic blood ethanol levels were examined following treatments. Developmental increases in the activities of mitochondrial enzymes, cytochrome oxidase (CO) and citrate synthase (CS), were observed. Ethanol exposure resulted in a depression in CO activity, but not CS activity. Since, a maximal depression in CO activity was seen with ethanol treatments of 75 mg/100 g, this dosing paradigm was adopted for subsequent experiments. A tissue-specific effect of ethanol was demonstrated as CO activity was unchanged in atrial, liver, pectoralis, and brain tissues. The role of mitochondrial DNA replication and transcription during the developmental up-regulation and ethanol-induced down-regulation of CO activity was evaluated using a cDNA probe for cytochrome oxidase subunit III (COIII). The relative levels of COIII mRNA and mitochondrial DNA (cpm/mg protein) decreased by 3-fold and 4-fold, respectively, across the developmental time course, while CO activity increased by 3.5-fold. Therefore, increases in mitochondrial DNA and mitochondrial mRNA transcripts are unlikely to be responsible for the developmentally-regulated increases in CO activity. Similarly, embryonic ethanol exposure failed to elicit alterations in COIII mRNA levels, indicating that the ethanol-induced depression in CO activity was not transcriptionally regulated. However, ventricular mitochondrial DNA concentrations were elevated in ethanol-treated embryos, indicating that ethanol-exposure either directly or indirectly induces mitochondrial DNA replication.

Mitochondrial DNA replication and transcription are dissociated during embryonic cardiac hypertrophy.

Cardiac hypertrophy was produced in embryonic chicks by decreasing the incubation temperature from 38 degrees C to 32 degrees C on day 11. Increases in ventricular protein, RNA, and DNA support the cardiac enlargement. Cytochrome-c oxidase activity and citrate synthase activity were depressed in hypothermic ventricles by 63% and 56%, respectively. No significant differences were seen in enzyme activities in pectoralis muscles. The involvement of mitochondrial gene replication and transcription was evaluated using a cDNA clone for the mitochondrially encoded subunit III of cytochrome-c oxidase (CO III). Quantitative slot-blot analysis demonstrated that the relative CO III mRNA concentration was reduced in hypothermic ventricles. In contrast, the relative mitochondrial DNA concentration was increased in hypothermic ventricles. Taken together, these data indicate that a hypothermia-induced decrease in cytochrome-c oxidase activity is associated with a decrease in CO III mRNA, which is not coupled to a decrease in the mitochondrial DNA copy number. This dissociation of mitochondrial gene replication and transcription may provide a useful model for examining the regulation of mitochondrial biogenesis.

Histochemical and biochemical analysis of myosin heavy chain expression during cardiogenesis in the rat.

Little is known about the tissue-specific expression of contractile proteins during cardiogenesis in the mammalian heart. Since the myosin heavy chain (HC) isoform expressed in the adult correlates with myocardial functional capacity, we undertook an analysis of myosin HC expression in atrial and ventricular myocardia during fetal cardiogenesis in the rat heart. Cardiac HCs were separated by electrophoresis under denaturing conditions. The expression of the predominant adult isoform HC alpha was localized within developing fetal cardiac chambers by immunohistochemistry with a specific monoclonal antibody (R 37). Results demonstrated that myosin HC isoform expression followed tissue-specific patterns during cardiogenesis in the rat. Atrial myocytes expressed HC alpha throughout development. The ventricles expressed exclusively HC alpha in the adult, but HC beta expression predominated in fetal ventricles. Fetal ventricles also expressed minor amounts of HC alpha, whose amount and distribution varied with developmental stage. HC alpha was initially confined to tracts of cells in the trabeculae, suggestive of future conduction system cells. A more extensive population of HC alpha-expressing cells appeared several days before birth in a pattern which could represent the prenatal initiation of HC alpha expression in working myocardial cells. These results indicate that there is tissue-specific developmental modulation of myosin isoform expression during fetal development. Results also demonstrated that this modulation may include expression of a third electrophoretically distinct myosin HC in fetal hearts.

Evidence for expression of a common myosin heavy chain phenotype in future fast and slow skeletal muscle during initial stages of avian embryogenesis.

We have utilized a key biochemical determinant of muscle fiber type, myosin isoform expression, to investigate the initial developmental program of future fast and slow skeletal muscle fibers. We examined myosin heavy chain (HC) phenotype from the onset of myogenesis in the limb bud muscle masses of the chick embryo through the differentiation of individual fast and slow muscle masses, as well as in newly formed myotubes generated in adult muscle by weight overload. Myosin HC isoform expression was analyzed by immunofluorescence localization with a battery of anti-myosin antibodies and by electrophoretic separation with SDS-PAGE. Results showed that the initial myosin phenotype in all skeletal muscle cells formed during the embryonic period (until at least 8 days in ovo) consisted of expression of a myosin HC which shares antigenic and electrophoretic migratory properties with ventricular myosin and a distinct myosin HC which shares antigenic and electrophoretic migratory properties with fast skeletal isomyosin. Similar results were observed in newly formed myotubes in adult muscle. Future fast and slow muscle fibers could only be discriminated from each other in developing limb bud muscles by the onset of expression of slow skeletal myosin HC at 6 days in ovo. Slow skeletal myosin HC was expressed only in myotubes which became slow fibers. These findings suggest that the initial commitment of skeletal muscle progenitor cells is to a common skeletal muscle lineage and that commitment to a fiber-specific lineage may not occur until after localization of myogenic cells in appropriate premuscle masses. Thus, the process of localization, or events which occur soon thereafter, may be involved in determining fiber type.