Teaching ethics to nurses.

Educating nurses about ethics is more complex, multidimensional, and time consuming than educating nurses about technical skills. Many factors, including the ability of the nurse to view situations holistically, the moral development of the nurse, and the institution's ethics, are involved. To illustrate how to teach nurses ethics, two examples of programs are detailed in this article.

Bedtime insulin/daytime glipizide. Effective therapy for sulfonylurea failures in NIDDM.

Bedtime insulin (BI)/daytime sulfonylurea (DSU) therapy was studied double-blind in 30 non-insulin-dependent diabetes mellitus subjects in whom sulfonylurea (SU) therapy had failed. Subjects were switched to glipizide for 2 months (phase I) to confirm failure (fasting plasma glucose [FPG] 12.0 +/- 0.4 mmol/l) and then randomly assigned into three groups: BI-DSU; BI-no DSU; and DSU-no BI. During phase II (3 months), the BI dose was fixed (20 U/1.73 m2, low-dose). In phase III (3 months), BI was titrated up (high-dose) to achieve good control or until hypoglycemic symptoms prevented further dose increases. In phase IV (6 months), 25 of the 30 original subjects received open-labeled, high-dose BI-DSU. Low-dose BI-DSU markedly reduced FPG (13.6 +/- 0.8 to 8.0 +/- 0.6 mmol/l, P < 0.001), mean 24-h glucose (P < 0.001), HbA1c (8.9 +/- 0.7 to 7.6 +/- 0.3%, P = 0.07), and basal hepatic glucose production (HGP) (P < 0.005). A positive correlation (r = 0.69, P < 0.05) between the declines in FPG and HGP was observed. Neither low-dose BI alone nor DSU alone reduced FPG, mean 24-h glucose, HbA1c, or basal HGP. High-dose (40 +/- 5 U/day) BI plus DSU further reduced the FPG (6.3 +/- 0.6 mmol/l), HbA1c (7.1 +/- 0.3%), mean 24-h plasma glucose, and basal HGP (all P < 0.05 vs. phase II).(ABSTRACT TRUNCATED AT 250 WORDS)

Protein coordination to manganese determines the high catalytic rate of dimanganese catalases. Comparison to functional catalase mimics.

Catalysis of hydrogen peroxide dismutation by the dimanganese catalase from Thermus thermophilus has been measured and found to obey Michaelis-Menton kinetics with no evidence for substrate inhibition at concentrations up to 0.45 M H2O2. Comparison among three dimanganese catalases (Thermus thermophilus, Thermoleophilium album, and Lactobacillus plantarum) reveals that their apparent second-order rate constants, Kcat/Km, differ by at most a factor of 5, even though the individual kinetic constants differ by as much as a factor of 20. This similarity suggests that all three enzymes may have the same rate-determining step. For T. thermophilus catalase we find that kcat/Km approximately kbi, the bimolecular rate constant at limiting substrate concentrations. Thus, the rate of the rate-determining step is unaltered over the entire range of substrate concentrations, unlike T. album and L. plantarum catalases where substrate inhibition has been reported. Comparison to structurally characterized dimanganese complexes and dimetalloproteins (arginase, hemerythrin), which are functional, albeit kinetically slow, catalase mimics, reveals that high catalase activity correlates with a greater number of stronger sigma-ligand donors like anionic carboxylatos vs neutral histidines that stabilize the oxidized Mn2(III,III) state over reduced Mn2(II,II). A critical feature for enzymatic functionality in vivo is suppression of one-electron chemistry leading to formation of the mixed-valence forms, Mn2(III,IV) and Mn2(II,III), which are kinetically inactive or precursors to inactive species, respectively. Evidence is presented from model compounds suggesting that the mu-carboxylato bridge between Mn ions in catalase may play the key role in suppressing formation of these detrimental oxidation states through destabilization of these one-electron redox processes.

Characterization of cellular defects of insulin action in type 2 (non-insulin-dependent) diabetes mellitus.

Seven non-insulin-dependent diabetes mellitus (NIDDM) patients participated in three clamp studies performed with [3-3H]- and [U-14C]glucose and indirect calorimetry: study I, euglycemic (5.2 +/- 0.1 mM) insulin (269 +/- 39 pM) clamp; study II, hyperglycemic (14.9 +/- 1.2 mM) insulin (259 +/- 19 pM) clamp; study III, euglycemic (5.5 +/- 0.3 mM) hyperinsulinemic (1650 +/- 529 pM) clamp. Seven control subjects received a euglycemic (5.1 +/- 0.2 mM) insulin (258 +/- 24 pM) clamp. Glycolysis and glucose oxidation were quantitated from the rate of appearance of 3H2O and 14CO2; glycogen synthesis was calculated as the difference between body glucose disposal and glycolysis. In study I, glucose uptake was decreased by 54% in NIDDM vs. controls. Glycolysis, glycogen synthesis, and glucose oxidation were reduced in NIDDM patients (P < 0.05-0.001). Nonoxidative glycolysis and lipid oxidation were higher. In studies II and III, glucose uptake in NIDDM was equal to controls (40.7 +/- 2.1 and 40.7 +/- 1.7 mumol/min.kg fat-free mass, respectively). In study II, glycolysis, but not glucose oxidation, was normal (P < 0.01 vs. controls). Nonoxidative glycolysis remained higher (P < 0.05). Glycogen deposition increased (P < 0.05 vs. study I), and lipid oxidation remained higher (P < 0.01). In study III, hyperinsulinemia normalized glycogen formation, glycolysis, and lipid oxidation but did not normalize the elevated nonoxidative glycolysis or the decreased glucose oxidation. Lipid oxidation and glycolysis (r = -0.65; P < 0.01), and glucose oxidation (r = -0.75; P < 0.01) were inversely correlated. In conclusion, in NIDDM: (a) insulin resistance involves glycolysis, glycogen synthesis, and glucose oxidation; (b) hyperglycemia and hyperinsulinemia can normalize total body glucose uptake; (c) marked hyperinsulinemia normalizes glycogen synthesis and total flux through glycolysis, but does not restore a normal distribution between oxidation and nonoxidative glycolysis; (d) hyperglycemia cannot overcome the defects in glucose oxidation and nonoxidative glycolysis; (e) lipid oxidation is elevated and is suppressed only with hyperinsulinemia.

An internal marketing approach to total service quality: a guide for practitioners.

For many organizations, the emphasis today is the development of total service quality. To achieve these goals, organizations must not only apply the marketing concept to external targets, but also plan and control internal facets of their operations. The purpose of the present article is to develop the rationale for Total Service Quality (TSQ) based on an Internal Marketing Approach (IMA) as well as to posit the steps necessary to implement an IMA.

Total body fat content and fat topography are associated differently with in vivo glucose metabolism in nonobese and obese nondiabetic women.

In this study, total body fat content and fat topography were related to glucose metabolism in the basal and insulin-stimulated states in 18 nonobese and 18 obese premenopausal nondiabetic women. All subjects received a euglycemic insulin (20 mU.min-1.m2) clamp study in combination with [3-3H]-D-glucose infusion and indirect calorimetry to quantitate total body glucose uptake, glucose oxidation, and nonoxidative glucose disposal. Total body fat content was determined with tritiated water, whereas body fat distribution was estimated from the WHR, the STR, and the VSR (measured by magnetic resonance imaging). In the postabsorptive state, total body glucose utilization, glucose oxidation, and nonoxidative glucose disposal rates were similar in nonobese and obese women, whereas during the insulin clamp all three metabolic parameters were reduced significantly in the obese group. In nonobese women, total body fat content was related inversely to both total and nonoxidative glucose disposal during the insulin clamp, whereas no relationship was found between glucose metabolism (total, oxidative, and nonoxidative) and WHR, STR, or VSR. In contrast, in obese women, no relationship was observed between total body fat content and any measure of insulin-mediated glucose metabolism. However, both WHR and VSR were related inversely to total, oxidative, and nonoxidative glucose disposal rates during the insulin clamp. These results suggest that total body fat content and body fat topography are associated differently with insulin-mediated glucose metabolism in nonobese and obese women. In the nonobese women, total body fat mass appears to be a primary determinant of tissue sensitivity to insulin, whereas in obese women, body fat topography exerts a more dominant effect.

Effect of insulin on oxidative and nonoxidative pathways of free fatty acid metabolism in human obesity.

The dose-response relationship between the plasma insulin concentration and oxidative and nonoxidative pathways of free fatty acid (FFA) metabolism was examined in 11 obese and 7 lean subjects using a stepwise insulin clamp technique in combination with indirect calorimetry and infusion of [1-14C]palmitate. The fasting plasma FFA concentration was elevated in obese subjects (793 +/- 43 vs. 642 +/- 39 mumol/l; P less than 0.01) and was associated with an increased basal rate of plasma FFA turnover, FFA oxidation, and nonoxidative FFA disposal, i.e., reesterification (all P less than 0.01). Suppression of plasma FFA turnover by physiological increments in plasma insulin was impaired in obese compared with lean subjects. However, plasma FFA turnover expressed per kilogram fat mass was normally suppressed by insulin in obese subjects. Although insulin suppressed plasma FFA oxidation to the same extent in lean and obese subjects, inhibition of total lipid oxidation by insulin was impaired in the obese group. Obese subjects had an enhanced basal rate of nonoxidative FFA disposal, which was suppressed less by physiological increments in plasma insulin compared with lean controls. Therefore, we conclude that 1) lipolysis in uncomplicated obesity is normally sensitive to insulin; the enhanced FFA flux is simply a consequence of the increased fat mass. 2) Nonoxidative FFA disposal expressed per lean body mass is enhanced in obese subjects and correlates with the increase in plasma FFA concentration and fat mass. 3) Enhanced oxidation of intracellular lipids contributes to the enhanced rate of total lipid oxidation in obese subjects.

Evaluating health care services from the perspective of the elderly.

The increasingly important over-50 age group continues to grow, presenting a unique segment for health care marketers. The present study examines the elderly's expectations and perceptions of service quality, exploring the relationship between service quality and age. In addition, the study investigates the relationship between the image of an out-patient clinic and the perceived level of service quality. The findings suggest that the elderly expect more information and more personalized attention from the multiple health care providers associated with each service encounter. Implications for exceeding the elderly's expectation of service quality and future research directions are also presented.

Quantitative assessment and training of isometric cervical extension strength.

The purpose of this study was to evaluate the reliability and variability of repeated measurements of isometric cervical extension strength and determine the effect of 10 weeks of dynamic variable resistance cervical extension training on isometric cervical extension strength. Seventy-three subjects (age, 29 +/- 12 years [mean +/- SD]) completed isometric cervical extension strength tests on 4 separate days (D1, D2, D3, and D4). For each test, isometric cervical strength was measured at 126 degrees, 108 degrees, 90 degrees, 72 degrees, 54 degrees, 36 degrees, 18 degrees, and 0 degrees of cervical flexion. Between-day correlation coefficients over the eight angles of cervical flexion were high for D2 versus D3 (r = 0.90 to 0.96). Test variability (standard error of estimate) between D2 versus D3 was low (7.4% to 10.2% of mean) through the entire range of motion. Regression analysis showed that the isometric cervical extension strength curve is linear and descending from flexion to extension. In a second study, 14 subjects (age, 25 +/- 3 years) trained the cervical extensor muscles for 10 weeks while 10 subjects (age, 23 +/- 3 years) served as controls. Training included 8 to 12 cervical extensions to volitional fatigue, 1 day per week. The training group improved isometric cervical extension strength at six of eight angles before to after training (P less than or equal to 0.05). During the same time period the control group did not change. These data indicate that repeated measures of isometric cervical extension strength are highly reliable and can be used for the quantification of isometric cervical extension strength through a 126 degrees range of motion.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of free fatty acid metabolism in the pathogenesis of insulin resistance in obesity and noninsulin-dependent diabetes mellitus.

To investigate the mechanisms of insulin resistance in obesity and noninsulin-dependent diabetes mellitus (NIDDM), we examined oxidative and nonoxidative pathways of free fatty acid (FFA) and glucose metabolism in 14 lean and 17 obese (with normal oral glucose tolerance) nondiabetic subjects and in 8 lean and 8 obese subjects with NIDDM. FFA and glucose metabolism were measured using the sequential insulin clamp technique in combination with indirect calorimetry and infusion of [3-3H]glucose and [1-14C]palmitate. Obesity was characterized by enlarged fat mass, which correlated positively with the plasma FFA concentration (r = 0.62; P less than 0.01). FFA metabolism was less sensitive to insulin in obese than in lean nondiabetic subjects, but this defect could be overcome by increasing the plasma insulin concentration. NIDDM patients showed normal sensitivity to the inhibitory action of insulin on FFA metabolism; however, maximal suppression by insulin was impaired. The combination of obesity and NIDDM was associated with a further enhancement of reesterification of FFA than observed in either condition alone. In both obesity and NIDDM, the dose-response curve for suppression of hepatic glucose production by insulin was impaired. While obesity was primarily characterized by reduced sensitivity to the stimulatory action of insulin on oxidative and nonoxidative pathways of glucose metabolism, resistance to the effect of insulin on glucose metabolism in NIDDM was characterized by a reduced maximal response. The combination of obesity and NIDDM further impaired the sensitivity of liver glucose output and glucose oxidation to insulin. The hypothesis is advanced that in uncomplicated obesity, increased availability and oxidation of FFA leads, by the FFA/glucose cycle, to the impairment in glucose utilization. In NIDDM, on the other hand, the defect in glucose utilization is primary, and the enhanced rate of FFA oxidation may represent a compensatory phenomenon.

Role of free fatty acids and insulin in determining free fatty acid and lipid oxidation in man.

Plasma FFA oxidation (measured by infusion of 14C-palmitate) and net lipid oxidation (indirect calorimetry) are both inhibited by insulin. The present study was designed to examine whether these insulin-mediated effects on lipid metabolism resulted from a decline in circulating FFA levels or from a direct action of the hormone on FFA/lipid oxidation. Nine subjects participated in two euglycemic insulin clamps, performed with and without heparin. During each insulin clamp study insulin was infused at two rates, 4 and 20 mU/m2.min for 120 min. The studies were performed with indirect calorimetry and 3-3H-glucose and 14C-palmitate infusion. During the control study plasma FFA fell from 610 +/- 46 to 232 +/- 42 to 154 +/- 27 mumol/liter, respectively. When heparin was infused basal plasma FFA concentration remained constant. During the control study, FFA/lipid oxidation rates decreased in parallel with the fall in the plasma FFA concentration. During the insulin/heparin study, plasma 14C-FFA oxidation remained unchanged while net lipid oxidation decreased. In conclusion, when the plasma FFA concentration is maintained unchanged by heparin infusion, insulin has no direct effect on FFA turnover and disposal. These results thus suggest that plasma FFA oxidation is primarily determined by the plasma FFA concentration, while net lipid oxidation is regulated by both the plasma FFA and the insulin level.

Dose-dependent effect of insulin on plasma free fatty acid turnover and oxidation in humans.

Methodology for measuring plasma free fatty acid (FFA) turnover/oxidation with [1-14C]palmitate was tested in normal subjects. In study 1, two different approaches (720-min tracer infusion without prime vs. 150-min infusion with NaH14CO3 prime) to achieve steady-state conditions of 14CO2 yielded equivalent rates of plasma FFA turnover/oxidation. In study 2, during staircase NaH14CO3 infusion, calculated rates of 14CO2 appearance agreed closely with NaH14CO3 infusion rates. In study 3, 300-min euglycemic insulin clamp documented that full biological effect of insulin on plasma FFA turnover/oxidation was established within 60-120 min. In study 4, plasma insulin concentration was raised to 14 +/- 2, 23 +/- 2, 38 +/- 2, 72 +/- 5, and 215 +/- 10 microU/ml. A dose-dependent insulin suppression of plasma FFA turnover/oxidation was observed. Plasma FFA concentration correlated positively with plasma FFA turnover/oxidation in basal and insulinized states. Total lipid oxidation (indirect calorimetry) was significantly higher than plasma FFA oxidation in the basal state, suggesting that intracellular lipid stores contributed to whole body lipid oxidation. Hepatic glucose production and total glucose disposal showed the expected dose-dependent suppression and stimulation, respectively, by insulin. In conclusion, insulin regulation of plasma FFA turnover/oxidation is maximally manifest at low physiological plasma insulin concentrations, and in the basal state a significant contribution to whole body lipid oxidation originates from lipid pool(s) that are different from plasma FFA.

Figure-ground organization in real and subjective contours: a new ambiguous figure, some novel measures of ambiguity, and apparent distance across regions of figure and ground.

This study was designed to assess the effects of organization, luminance contrast, sector angle, and orientation on a new, highly ambiguous Cs-keyhole figure. Organization and contrast were the most important factors, and sector angle also influenced figure-ground relationships. There was no significant effect of orientation, nor was there any significant interaction between any of the factors. Several new measures of figure-ground organization were developed, such as ambiguity ratios based on reaction times and on ratings of the strength of perceived organizations, providing new quantitative measures of figure-ground relationships. Distances measured across figural regions appeared smaller than equal distances across the ground in the new reversible figure, and also in Rubin's classic vase-face figure presented in real and subjective contours. Inducing a perceptual set to see a particular organization in a reversible figure influenced the apparent distance across that organization. Several possible explanations of the observed effects are considered: (1) an instance of Emmert's law, based on the difference in apparent depth of figure and ground; (2) an aspect of the Müller-Lyer illusion; (3) a feature-detector model of contour attraction; (4) a natural set or predisposition to see a figure as smaller; and (5) framing effects. The first two explanations appear the most promising.

Premenstrual syndrome: concerns, controversies, and treatment.

Premenstrual syndrome is of interest to health care professionals today because of media attention and large numbers of women who are concerned about their premenstrual symptoms. At the same time, there is a lack of consensus as to diagnostic criteria and specific treatment. There appears to be a relationship between mood disorders such as major depression and luteal phase symptoms. An approach to the diagnosis and treatment of the patient with premenstrual syndrome is described.