Intimacy: A behavioral interpretation

This paper proposes that intimacy is a process that emerges from a sequence of events in which behavior vulnerable to interpersonal punishment is reinforced by the response of another person. These intimate events result in an increase in the probability of behavior vulnerable to interpersonal punishment in the presence of the reinforcing partner. The process results in intimate partnership formation and reports of feeling intimate. In addition to positing an operant process integrating the various components of intimacy, the theory also posits that the punishment of interpersonally vulnerable behavior is an integral aspect of intimate partnership formation and that intimate partnerships can develop that reinforce behavior that may be destructive both to the individual and to others.

The sensitivity of ecosystem carbon exchange to seasonal precipitation and woody plant encroachment

Ongoing, widespread increases in woody plant abundance in historical grasslands and savannas (woody encroachment) likely will interact with future precipitation variability to influence seasonal patterns of carbon cycling in water-limited regions. To characterize the effects of woody encroachment on the sensitivity of ecosystem carbon exchange to seasonal rainfall in a semi-arid riparian setting we used flux-duration analysis to compare 2003-growing season NEE data from a riparian grassland and shrubland. Though less seasonally variable than the grassland, shrubland NEE was more responsive to monsoon rains than anticipated. During the 2004-growing season we measured leaf gas exchange and collected leaf tissue for delta(13)C and nitrogen content analysis periodically among three size classes of the dominant woody-plant, Prosopis velutina and the dominant understory species, Sporobolus wrightii, a C(4) bunchgrass, present at the shrubland. We observed size-class and plant functional type independent patterns of seasonal plant performance consistent with greater-than-anticipated sensitivity of NEE in the shrubland. This research highlights the complex interaction between growing-season precipitation, plant-available alluvial groundwater and woody plant abundance governing ecosystem carbon balance in this semi-arid watershed.

Ventricular-vascular uncoupling increases expression of B-type natriuretic peptide in heart transplantation

BACKGROUND

Allograft adaptation to a foreign circulation is imperfect as noted from persistent limitations to stress. Effective arterial elastance (Ea), a measure of afterload, provides an estimate of aortic impedance. End systolic elastance (Ees) is a load-independent measure of ventricular performance as well as its interaction in the periphery. The ratio (Ea to Ees) characterizes ventricular-vascular coupling; a value close to unity signifies poor mechanical efficiency. The purpose of this investigation was to correlate mechanical efficiency of work with expression of B-type natriuretic peptide BNP, a specific marker of ventricular stress and strain.

METHODS

We measured BNP levels in 40 consecutive stable heart transplant recipients free from rejection. In addition, echocardiography was performed to obtain Ea, Ees, and their ratio (Ea to Ees) by the single-beat method. We examined correlates of BNP expression by assessing Ea to Ees, while correcting for mean arterial pressure, body mass index, left ventricular mass index, ejection fraction, and serum creatinine.

RESULTS

BNP levels were significantly and positively correlated (r=0.38, P=.05) with an increased Ea to Ees ratio. By multivariable analysis, this relationship persisted independently (t=2.1, P=.04), while the five other measures were insignificant predictors.

CONCLUSION

This investigation indicated that the transplanted heart demonstrates poor contractile efficiency and operates at maximal left ventricular work. This is paralleled by a tandem increase in BNP, suggesting that elevation in this stress peptide is at least partly explained by ventriculo-vascular uncoupling in heart transplantation, independent of alterations in blood pressure.

Corticosteroid weaning in the tacrolimus and mycophenolate era in heart transplantation: Clinical and neurohormonal benefits

BACKGROUND

Compared with cyclosporine, tacrolimus-based immunosuppression yields improved metabolic outcomes in heart transplantation. Whether corticosteroid freedom provides incremental metabolic benefits in tacrolimus and mycophenolate mofetil immunoprophylaxis remains uncertain.

METHODS

In a prospective trial, 41 heart transplant patients treated with tacrolimus and mycophenolate mofetil underwent steroid weaning immediately after transplantation until weaning was complete. Weaning was interrupted only for treated rejection with or without hemodynamic compromise. Benefits of steroid weaning assessed following the first year included B-type natriuretic peptide (BNP), late infections, lipids, blood pressure, hyperglycemia, and body mass index (BMI).

RESULTS

Of this 41 patient cohort (age 53 +/- 9 years, 50% black American, 35% women) followed for a total of 47 +/- 5 months, 25 had corticosteroids discontinued (62%) by an average of 20 +/- 11 months. No differences between the two groups were noted in baseline characteristics. Significant predictors of failure to wean steroids included higher rejection, BNP, and lower dose of mycophenolate mofetil. No significant benefits of steroid weaning were noted on lipids, blood pressure, hyperglycemia, and BMI. However, late infections (after 1 year) requiring hospitalizations were more frequent in the failure to wean group (0.60.4 vs 0 infections/patient/y, P <.001).

INFERENCES

Unlike known metabolic benefits of steroid withdrawal with cyclosporine, heart transplant recipients treated with tacrolimus and mycophenolate mofetil demonstrate no incremental metabolic benefits, but instead experience benefits of decreased serious late infections. Furthermore, failure to discontinue corticosteroids in this series is predicted by early allograft rejection, use of lower doses of mycophenolate mofetil, and higher BNP levels suggesting poor cardiac adaptation.

Difficult cases in heart failure. Novel diagnostic markers in heart failure: an emerging paradigm shift?

The differential diagnosis of dyspnea can be overwhelming in the presence of competing diseases. The recent advent of the peptide marker brain natriuretic peptide has ushered in an era of refined diagnostic capability in heart failure. We present a clinical scenario to illustrate the usefulness of this new biomarker assay in directing appropriate therapy for heart failure. (c)2001 CHF, Inc.

Native mitral valve regurgitation. Proactive management can improve outlook

Mitral regurgitation is a common valvular abnormality that can result in substantial morbidity. Primary care physicians should maintain a high index of suspicion for this disorder, especially in patients with symptoms of heart failure. The paramount concern is early identification of patients with mitral regurgitation and prompt referral to a cardiologist when symptoms occur or if evidence of ventricular enlargement or reduction in ejection fraction is found. Echocardiography is an invaluable tool in determining the severity of regurgitation, the integrity of the mitral valve apparatus, the extent of left ventricular enlargement, and the ejection fraction. Although no standard medical treatment has been established for mitral regurgitation, use of ACE inhibitors is appropriate. Patients presenting with severe, acute mitral regurgitation from papillary muscle rupture should be evaluated for ischemia and treated expediently. The preferred operative procedure in patients with severe mitral regurgitation and left ventricular dysfunction is mitral valve repair, if possible, or mitral valve replacement with posterior chordal preservation, if feasible.

Recurrence of giant cell myocarditis in cardiac allograft

BACKGROUND

Giant cell myocarditis causes essentially irreversible fulminant left ventricular dysfunction with associated conduction abnormalities and congestive failure. Response to immunosuppressive therapy is poor and cardiac transplantation is the only viable treatment option. The histologic hallmarks of giant cell myocarditis include a polymorphous inflammatory response with numerous multinucleated giant cells and extensive myocyte necrosis in a geographic pattern. There were 38 patients who received a cardiac transplant for giant cell myocarditis in the Giant Cell Myocarditis Registry. Among these patients, there were 9 recurrences of disease in the allograft. Concern has been expressed that recurrence of giant cell myocarditis in the allograft might be a contraindication for cardiac transplantation in the future.

METHODS

In our single-center analysis we describe the clinical and histologic findings of 5 patients transplanted for giant cell myocarditis at the Cleveland Clinic.

RESULTS

All but 1 of the patients were New York Heart Association (NYHA) class 4 with an average cardiac index (CI) of 1.52 liters/min x m(2). Of the 5 patients transplanted, 1 developed recurrent giant cell myocarditis. Routine right ventricular endomyocardial biopsy at 1 week exhibited severe multifocal myocardial fibrosis in addition to mild acute vascular rejection and mild grade 1A cellular rejection. Follow-up biopsy in this patient indicated grade IIIA moderate acute rejection in addition to multinucleated giant cells. Two distinct inflammatory processes were noted consisting of foci of T-cell inflammation identified by immunohistochemistry to be consistent with rejection, and a second inflammatory process with few mononuclear cells staining for macrophage or T-cell markers with eosinophils and myocyte necrosis consistent with giant cell myocarditis. Follow-up right ventricular endomyocardial biopsies (RVBXs) in this patient have subsequently demonstrated improvement in the degree of inflammatory infiltrate without vascular or significant cellular rejection. Vascular rejection was noted in 1 of the remaining 4 patients and was treated successfully with muramab-CD3 and plasmapheresis.

CONCLUSIONS

Giant cell myocarditis should be expected to recur in the allograft and often does so concurrently with rejection. However, the disease in the allograft responds to therapy in a favorable manner, which differs dramatically from that in the native heart. This might be the result of detection of the disease at an earlier stage than in the native heart, or the immunosuppression milieu in the allograft. The favorable response to therapy suggests that the likelihood of recurrence of giant cell myocarditis should not be considered a barrier to transplantation.

Blockage of one class of potassium channel alters the effectiveness of halothane in a brain circuit of Drosophila

At concentrations comparable to those used in the clinic, halothane has profound effects on a neuronal pathway devoted to the escape reflex of the fruit fly, Drosophila melanogaster. We studied the influence of the potassium channel that is encoded by the Shaker gene on the halothane sensitivity of this circuit. Shaker channels were specifically inactivated either by genetic means, using strains with two different severe Shaker mutations, or by pharmacologic means, using ingestion of millimolar concentrations of 4-aminopyridine. In all cases, halothane potency decreased substantially. To ensure that the genetic alteration was specific, both mutations were studied as stocks that had been repeatedly backcrossed to a control strain. The specificity of the pharmacologic inhibition was demonstrated by the fact that 4-aminopyridine had no effect on halothane potency in a Shaker mutant. Quantitative differences in the effects of channel inhibition between males and females suggested a sexual dimorphism in the functional brain anatomy of the reflex circuit.

Expression of leukemia inhibitory factor receptor mRNA in sensory dorsal root ganglion and spinal motor neurons of the neonatal rat

Previous studies have shown that the application of leukemia inhibitory factor to the proximal nerve stump prevents the degeneration of axotomized sensory neurons in the dorsal root ganglion and motor neurons in the spinal cord of newborn rats. This study investigated the expression of leukemia inhibitory factor receptor mRNA in these neurons using in situ hybridization. Leukemia inhibitory factor receptor mRNA was detected both in sensory neurons within the dorsal root ganglion and motor neurons of the cervical spinal cord. Twenty-four hours after axotomy these neurons continue to express leukemia inhibitory factor receptor mRNA. This pattern of leukemia inhibitory factor receptor expression provides a mechanism by which endogenous and exogenous leukemia inhibitory factor could act on injured sensory and motor neurons.

Evaluation of a mobile crisis program: effectiveness, efficiency, and consumer satisfaction

OBJECTIVE

The effectiveness and efficiency of a mobile crisis program in handling 911 calls identified as psychiatric emergencies were evaluated, and the satisfaction of consumers and police officers with the program was rated.

METHODS

The study retrospectively examined differences in subjects' demographic characteristics, hospitalization and arrest rates, and costs for 73 psychiatric emergency situations handled by a mobile crisis team and 58 psychiatric emergency situations handled by regular police intervention during three months in 1995. Consumers' and police officers' satisfaction with the mobile crisis program was evaluated through Likert-type scales.

RESULTS

Fifty-five percent of the emergencies handled by the mobile crisis team were managed without psychiatric hospitalization of the person in crisis, compared with 28 percent of the emergencies handled by regular police intervention, a statistically significant difference. The difference in arrest rates for persons handled by the two groups was not statistically significant. The average cost per case was 23 percent less for persons served by the mobile crisis team. Both consumers and police officers gave positive ratings to the mobile crisis program.

CONCLUSIONS

Mobile crisis programs can decrease hospitalization rates for persons in crisis and can provide cost-effective psychiatric emergency services that are favorably perceived by consumers and police officers.

Long-term outcome of cardiac allograft vasculopathy treated by transmyocardial laser revascularization: early rewards, late losses

Transmyocardial laser revascularization (TLR) was initially touted as a promising therapeutic alternative for tackling the growing problem of cardiac allograft vasculopathy in late heart transplant survivors. We first described 4- and 8-week observations of application of this surgical technique, in which we professed enthusiasm for TLR in providing symptomatic relief and in reducing ischemic burden. In this report, we present the long-term (24-month) impact of TLR on clinical outcome, channel patency, and recrudescence of ischemic burden. In the long term, surgical TLR provides neither consistent symptomatic improvement nor an ameliorative effect on the natural history of cardiac allograft vasculopathy.

A new assay for the genetic study of general anesthesia in Drosophila melanogaster: use in analysis of mutations in the X-chromosomal 12E region

We describe a new measure of the influence of general anesthetics on Drosophila that uses the robust tendency of fruit flies to briskly walk upwards after being tapped down. We expose flies to a fixed concentration of anesthetic gas in a 50 ml tube for a period of up to 1 h and then test the distribution of flies in the tube shortly after tapping them to its bottom. By measuring the effect of a series of anesthetic concentrations on the fraction of flies that fail to climb, we derive quantitative descriptors of the potency of the drug. This "distribution test" is superior to previous assays of anesthetic potency in terms of ease and reliability. We have used the assay to further the genetic analysis of several mutations that cluster on the X chromosome and are known to influence both neural function and anesthesia sensitivity. The results establish complementation patterns between the mutations, refine their genetic map positions, and open the way for the molecular identification of the relevant gene(s).

The MMPI-2 in Perú: a normative study

In this study, we compared a Peruvian normative group to the standard Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989b) U.S. normative sample. The MMPI-2 Hispanic Version was administered under standardized conditions to participants with a wide range of age, educational, occupational, and socioeconomic levels. Between the 2 samples, there was a high degree of similarity across most basic and supplementary scales. Elevations (Ts = 60-65) were found on Scale F for men and women and Scales Mf and MDS for women only. For both men and women, small elevations (Ts = 55-60) were found on several other scales. The differences were consistent with those found in other Latin American populations. The results of this study suggest that the adaptation of the MMPI-2 with the U.S. norms is appropriate for use in Perú.

Intravenous thyroid hormone supplementation in heart failure with cardiogenic shock

BACKGROUND

Thyroid hormone level abnormalities commonly exist in severe heart failure and may be of prognostic value. The therapeutic potential of using thyroid hormone for cardiogenic shock resulting from progressive heart failure has not been previously delineated. We sought to evaluate the role of an intravenous infusion of thyroxine as an adjunct to conventional inotropic agents and intra-aortic balloon counterpulsation in patients with severe heart failure with cardiogenic shock.

METHODS AND RESULTS

We studied 10 consecutive patients with severe systolic heart failure that progressed to a cardiogenic shock state unresponsive to conventional pharmacological inotropic measures. Intravenous thyroxine (20 micrograms/h) was used as an adjunctive salvage measure after the failure of conventional pharmacological and mechanical support by intra-aortic balloon pump. The invasive hemodynamic profile (right atrial pressure, pulmonary capillary wedge pressure, cardiac index, mean arterial pressure), overall clinical status, core temperature, renal function, and tachyarrhythmias were compared before and sequentially at 6, 24, and 36 hours after the initiation of thyroxine administration. Long-term outcome was also defined. All patients had statistically significant improvements in cardiac index, pulmonary capillary wedge pressure, and mean arterial pressure at 24 and 36 hours post-initiation of thyroxine. No sustained tachyarrhythmias were seen during the thyroxine infusion. In 9 of 10 patients who underwent left ventricular assist device placement and/or heart transplantation, the use of thyroxine served as an effective adjunctive measure to allow transitioning to definitive surgical therapy. The 6-month and 1-year cohort survival rates, achieved by the transition to surgical therapy, were 90% and 80%, respectively.

CONCLUSION

The beneficial hemodynamic properties of intravenous thyroid hormone can be effectively used in otherwise terminal situations of cardiogenic shock, and in such situations, the use of thyroid hormone can serve as a pharmacological adjunct to a definite surgical intervention. Further studies in larger numbers of patients might be warranted to confirm these findings.

An interview with Rick Scott. Interview by Connie R Curran

Richard (Rick) L. Scott is president and chief executive officer of Columbia/HCA Healthcare Corporation, the nation's largest health care services provider. In this interview, he discusses principles of patient care, measuring and sharing systems, the future of academic health centers, and the importance of information dissemination.

Small bowel Procardia XL tablet bezoar mimicking cystic pneumatosis intestinalis

Procardia XL Extended Release Tablets are being used with increasing frequency in the treatment of angina and hypertension. Bezoar formation, secondary to retained insoluble medication shells, is an important but less well-known complication. We report the first case of a small bowel bezoar due to this unique medication system.

Relevance of body weight to apolipoprotein levels in Australian children

OBJECTIVES

To assess weight and apolipoprotein profiles in a representative sample of primary school children.

PARTICIPANTS AND SETTING

1543 children (936 girls and 607 boys) aged 6-11 years from schools in the Eastern Sydney Area Health Service region in 1994.

METHODS

We measured body mass index (BMI) and capillary blood apolipoprotein (apo) B and A-I levels (the carrier proteins for low and high density lipoprotein cholesterol, respectively) as well as lipoprotein (Lp) (a). We related BMI levels to those documented in the 1985 Australian Council on Health, Physical Education and Recreation (ACHPER) survey of school children.

RESULTS

Compared with the ACHPER distribution, BMI was increased in the boys but not in the girls; 16.8% of boys were above the 90th percentile of the ACHPER distribution (P = 0.003) and only 6.5% were below the 10th percentile (P = 0.046). There were 45 boys (7.4%) and 53 girls (5.7%) with BMIs above the 95th percentile who were, by definition, obese. They had highly significant increases in apo B (P = 0.003) and apo B: apo A-I ratio (P = 0.0001) compared with children in the normal BMI range (10th-90th percentiles); and 20% of the population, including the obese group, also had Lp(a) levels greater than 300 mg/L. The results in children aged 10 and 11 years were not different from those of the whole group, consistent with an absence of possible confounding effects due to early puberty or smoking.

CONCLUSIONS

There was an increase in weight relative to height in boys aged 6-11 years in eastern Sydney, compared with the 1985 ACHPER survey. In both boys and girls with the highest BMI category, levels of apo B and the apo B: apo A-I ratio were significantly increased. As these apolipoprotein changes are correlated closely with early onset atherogenesis and are correctable, their identification offers prospects for prevention.

Lipoprotein alterations in the spontaneously hypertensive rat fed diets deficient in selenium and vitamin E

Both vitamin E and selenium (Se) are antioxidant nutrients that play important roles in preventing in vivo lipid peroxidation. In this investigation, Se and vitamin E were found to influence lipoprotein levels in the spontaneously hypertensive rat (SHR). Four-week-old inbred SHRs were fed a basal (B) diet with 1% cholesterol deficient in both selenium and vitamin E (B+cho diet) or identical diets to which either vitamin E (B+E+cho) or selenium (B+Se+cho) or both micronutrients were added (B+Se+E+cho). Plasma-cho and lipoprotein-cho levels were measured after 6, 12, 16, and 18 weeks of feeding the experimental diets. Rats fed the B+cho diet for at least 12 weeks had plasma-cho levels about twice that observed for rats fed the B+E+Se+cho diet. Plasma-cho levels for rats in the two Se deficient groups (B+cho and B+E+cho) were, however, similar at any time point. Se deficiency was associated with increased plasma-cho, very low density lipoprotein-cho (VLDL-cho) and low-density lipoprotein-cho (LDL-cho). Vitamin E supplementation interacted with Se deficiency to increase plasma VLDL-cho levels. Neither vitamin E alone nor the interaction between vitamin E and Se consistently influenced LDL-cho levels. The percent cholesteryl ester in LDL from rats fed the Se-deficient diets (B+cho or B+E+cho) was at least twice that observed for rats fed the B+E+Se+cho diet. Plasma lipid peroxidation products were highly elevated in rats fed the B+cho diet compared with values for the B+E+cho or the B+E+Se+cho fed rats (which were not significantly different). These results suggest that dietary Se deficiency increases plasma-cho, VLDL-cho, and LDL-cho levels by a mechanism that may be unrelated to its role as an antioxidant nutrient.

Altered hepatic catabolism of low-density lipoprotein subjected to lipid peroxidation in vitro

Recent evidence suggests that oxidatively modified forms of low-density lipoprotein (LDL) may be particularly atherogenic. In this investigation, the catabolism of human LDL modified by lipid peroxidation in vitro was studied with a recirculating rat liver perfusion system. A dual-labelling technique was used that permitted native LDL and modified LDL to be studied simultaneously in the liver perfusion system. Native human LDL was found to have a fractional catabolic rate (FCR) of 1.00 +/- 0.21%/h, in agreement with other investigators. Subjecting LDL to oxidation for 12 h in the presence of 30 microM FeEDTA did not significantly affect its FCR. LDL treated with a superoxide-generating system (xanthine oxidase, hypoxanthine, O2) in the presence of 30 microM FeEDTA did, however, show a significant increase in FCR (3.23 +/- 0.19%/h). The hepatic uptakes of native LDL and LDL oxidized with FeEDTA+O2 were similar, but both were significantly lower than the hepatic uptake of LDL treated with the superoxide-radical-generating system. The proteolysis of LDL with pancreatin did not influence either its susceptibility to oxidation or its FCR. LDL oxidation resulted in the preferential loss of alpha-tocopherol rather than gamma-tocopherol. These data indicate that the rat liver effectively catabolizes LDL oxidatively modified by treatment with the superoxide-generating system. Furthermore, our results suggest that only very low plasma levels of highly oxidized LDL could be found under conditions in vivo. The liver may therefore play a major role in protecting the arterial vasculature from highly atherogenic forms of LDL.

Somatization and malingering for workers' compensation applicants: a cross-cultural MMPI study

A post hoc analysis was conducted of 60 Hispanics and 60 Caucasians who had filed claims under workers' compensation. The study examined cross-cultural differences of somatization and malingering as assessed by the MMPI. Somatization was assessed by analyzing two- and three-point code types based on scales 1 (Hs), 2 (D), and 3 (Hy) of the MMPI, using the cut-off criterion of T > or = 70. Malingering was determined by analysis of the dissimulation index from the MMPI (F-K > +9). Significant differences were found for somatization; Hispanics were more likely to somatize. Minimal differences were found between Hispanic and Caucasian subjects on the malingering scale.

Social support of mothers of children with mental retardation

Utilization of social support and perceptions of family stress of 80 mothers with a child who had mental retardation were examined. Measures of family stress and social support were administered to subjects with a child in one of three normative transition periods. There were no significant differences in family stress scores across the groups. Analysis of variance procedures revealed significant differences in the utilization of intimate support across the age groups. Implications for further research in this area were discussed.

The role of selenium in the secretion of very-low-density lipoprotein in the isolated perfused rat liver

A recirculating liver perfusion system was used to study the effects of dietary selenium (Se) on the hepatic secretion of very-low-density lipoprotein (VLDL). The perfusate from livers of rats fed on a Se-deficient diet incorporated about 50% more [1-14C]oleic acid into triacylglycerol (TG) and cholesteryl esters (ChoEs) than did the perfusate from livers of rats fed on a Se-supplemented diet. Similarly, livers from rats fed the Se-deficient diet secreted more VLDL and incorporated about 60% more [1-14C]oleic acid into VLDL TG and ChoEs than did livers from rats fed the Se-supplemented diet. The liver perfusate from rats in the Se-deficient group also showed significantly decreased fatty acid oxidation. We conclude that Se is a potent modulator of lipoprotein metabolism. A primary action of Se deficiency appears to be a decrease in fatty acid oxidation and a stimulation of fatty acid esterification, leading to increased VLDL TG and ChoEs formation and secretion.