Social comparisons of income in one's community: evidence from national surveys of income and happiness.

Two studies provide evidence for social comparison effects of income on subjective well-being (SWB). The 1st study of 7,023 persons from nationally representative samples in the United States shows that the range and skew of the income distribution in a community affects a person's happiness, as predicted by range-frequency theory. The 2nd study of 8 nations over a period of 25 years shows that decreasing the skew (inequality) of the income distribution in a country increases average national SWB. Both studies strongly support social comparison effects of income within a community, and both results are predicted by range-frequency theory. These studies are the first to successfully extend earlier results of R. H. Smith, E. Diener, and D. H. Wedell (1989) from the laboratory into naturalistic situations. The magnitude of the social comparison effects is smaller than the main effect of income, which implies that nations can avoid creating a "hedonic treadmill."

The in-vivo cardiovascular effects of a putative class III anti-arrhythmic drug, AM 92016.

AM 92016 (1-(4-methanesulphonamidophenoxy)- 3-(N-methyl-3-4-dichlorophenethylamino)-2-propanol benzoic acid salt), an oxypropanolamine analogue of sotalol, has been shown to possess Class III anti-arrhythmic properties in-vitro at concentrations showing 1000 times more potency than sotalol. The aim of this study was to characterize the effects of AM 92016 in-vivo. When administered to anaesthetized guinea-pigs, AM 92016 (10 micrograms kg-1 -5 mg kg-1) significantly increased heart rate, systolic arterial blood pressure, left ventricular systolic pressure and the contractile index dp dtmax. AM 92016 also significantly decreased the QT interval of the electrocardiogram from 135 +/- 10 to 105 +/- 4 ms (5 mg kg-1). The time to onset of the first arrhythmia and ventricular fibrillation, induced by intravenous infusion of ouabain, was shortened in the presence of AM 92016. Ouabain-induced ventricular fibrillation occurred at 18 +/- 5 and 12 +/- 3 min (P < 0.05) in control and AM 92016-(1 mg kg-1) treated guinea-pigs, respectively. An infusion of AM 92016 (2.5 micrograms kg-1 min-1) to anaesthetized pigs significantly increased the total number of arrhythmias occurring following coronary artery occlusion from 266 +/- 26 in control pigs to 535 +/- 148 (P < 0.05) in those receiving AM 92016. The time to onset of ventricular fibrillation was also significantly reduced in anaesthetized pigs from 24 +/- 1 to 18 +/- 3 min in the presence of AM 92016. The drug did not change haemodynamics in the anaesthetized pig. We conclude that AM 92016 exhibited proarrhythmic rather than antiarrhythmic activity when administered in-vivo to either guinea-pigs or pigs.

Effects of diltiazem and its analogue siratiazem on contraction and 45Ca2+ uptake in sheep coronary artery rings.

1. Siratiazem, an analogue of diltiazem designed to be resistant to N-demethylation, was compared with diltiazem for inhibition of Ca(2+)-induced contraction of depolarized coronary artery rings from the sheep. There was no significant difference in potency between siratiazem and diltiazem in the presence of normal physiological salt solution (IC25 for siratiazem 0.13 +/- 0.04 microM and for diltiazem 0.08 +/- 0.02 microM) or one mimicking some of the conditions that occur during myocardial ischaemia (hypoxia, acidosis, reduced glucose and addition of lactate). 2. K(+)-stimulated 45Ca2+ uptake in coronary artery rings was also inhibited by siratiazem and diltiazem with similar potencies. 3. It is concluded that siratiazem inhibits Ca2+ entry in coronary vascular smooth muscle equipotently with diltiazem and that this effect is not modified by some of the changes that occur during myocardial ischaemia.

Comparison of the effects of diltiazem and its analogue siratiazem on contractility in arteries, ileum and cardiac muscle.

1. The aim of this study was to compare the abilities of diltiazem and siratiazem to inhibit concentration-response curves for contractile responses to calcium in arterial and intestinal smooth muscle and cardiac muscle. 2. Diltiazem and siratiazem inhibited, in a concentration-dependent manner, the maximum contraction produced by cumulative addition of calcium chloride to rabbit mesenteric artery, ileum and paced atria in vitro. The order of potency, as indicated by the IC25 values (with 95% confidence intervals) for siratiazem was ileum, 0.33 microM (0-0.63) > mesenteric artery, 0.75 microM (0.32-1.01) and for diltiazem was ileum 0.1 microM (0.007-0.14) = mesenteric artery 0.13 microM (0-0.22). 3. In rabbit atria, the IC25 was of the order of 10 microM for both siratiazem and diltiazem. 4. Both drugs also inhibited calcium concentration-response curves in sheep cerebral arteries and in this tissue the IC25 values were 1.18 (0.37-1.63) and 0.89 (0-1.36) microM for siratiazem and diltiazem, respectively. 5. It is concluded that siratiazem, like diltiazem, blocks entry of calcium via voltage-operated channels with a similar potency to diltiazem on rabbit ileum and cardiac muscle and sheep cerebral arteries but is less potent on rabbit mesenteric arteries.

Does chronic fatigue syndrome predispose to non-Hodgkin's lymphoma?

Chronic fatigue syndrome, an illness that frequently is associated with abnormalities of cellular immunity, has been reported anecdotally to be associated with an increased incidence of lymphoid hyperplasia and malignancy. This report describes an initial analysis of population-based cancer incidence data in Nevada, focusing on the patterns of non-Hodgkin's lymphoma prior to and subsequent to well described, documented outbreaks of chronic fatigue syndrome during 1984-1986. In a study of time trends in four age groups, the observed time trends were consistent with the national trends reported in the Surveillance, Epidemiology, and End Results Program. No statistically significant increase attributable to the chronic fatigue syndrome outbreak was identified at the state level. Additional studies are in progress analyzing the data at the country level, reviewing patterns in other malignancies, and continuing to monitor the cancer patterns over subsequent years.

Effect of low- and high-fat intakes on the hormonal milieu of premenopausal women.

To compare the influence of low- and high-fat diets on hormone metabolism, we studied six premenopausal women over two complete menstrual cycles. After an initial 7-10 d dietary adjustment subjects were randomly assigned to either low- (25% of calories) or high-fat (46% of calories) diets. The diets were isocaloric and similar in proportions of protein, polyunsaturated:saturated fatty acid ratio, fiber, and cholesterol. All subjects completed both diets in a crossover experimental design. Fasting blood and 24-h urine samples were collected every other day. No significant differences in plasma luteinizing hormone, progesterone, prolactin, estrone (E1), and estradiol-17 beta (E2) or in urinary E1, E2, and estriol were observed. Prolactin secretion in response to thyrotropin-releasing hormone stimulation was also unchanged. Dietary fat may influence breast-cancer incidence by modulating the hormonal environment; however, an increase in short-term fat intake from 28 to 51 g/1000 kcal did not lead to substantial differences in the hormonal milieu.

Differential characteristics of two newly established human breast carcinoma cell lines.

Two human breast carcinoma cell lines, EP and MW, were established in culture from malignant pleural effusions. In addition to producing tumors in antithymocyte serum-immunosuppressed mice, both cell lines showed epithelial characteristics and anchorage-independent growth in soft agar. EP and MW differed in morphology (spindle-shaped versus round), chromosomal mode (hyperdiploid versus near triploid), estrogen receptor content (43.8 versus 5.1 fmol/mg protein), cloning efficiency (0.24 versus 15%), and activities (milliunits/10(6) cells) of creatine phosphokinase (25.7 versus 62.6) and lactate dehydrogenase (346.7 versus 778.5). Electron microscopy revealed that MW cells had more perinuclear filamentous material and more frequent intracytoplasmic vacuole formation than did EP cells. While having no effect on MW cells at the concentrations studied (10(-5) to 10(-11) M), beta-estradiol (10(-7) M) stimulated the growth of EP cells by 106% over the hormone-depleted control. In a variety of systems, EP was consistently the more drug sensitive of the two lines. In vitro, EP was significantly (p less than 0.001) more sensitive to methotrexate, vincristine, and 5-fluorouracil, respectively. In antithymocyte serum-mouse xenografts, EP displayed a greater response to three different dosages of a combination of cyclophosphamide, methotrexate, and 5-fluorouracil. One such dosage (cyclophosphamide, 32.0 mg/kg/day; methotrexate, 13.0 mg/kg/day; 5-fluorouracil, 190.0 mg/kg/day; for 1 day) reduced EP and MW tumor weights to 5.9 and 41% of controls, respectively. These results correlated well with the clinical responses.

Chronic dopaminergic sensitivity after Sydenham's chorea.

We studied psychometric performance on the Minnesota Multiphasic Personality Inventory (MMPI) mini-mult and drug-induced choreic reactions in a group of patients with a history of Syndenham's chorea. Action tremor, motor signs, and residual chorea were common. One-half of the patients reported adverse choreic reactions to one or more agents. Patients with adverse reactions to central stimulants and anorectics had statistically significant elevations in the psychotic tetrad of the MMPI. Sydenham's chorea in childhood seems to confer persistent sensitivity to agents that augment central dopaminergic activity, which may be expressed as acute chorea. Central dopaminergic sensitivity may explain earlier reports of psychologic difficulties in survivors of rheumatic chorea.

PIP: 32 patients with Sydenham's chorea were studied at the La Rabida Institute for psychometric performance on the Minnesota Multiphasic Personality Inventory (MMPI). Questionnaires used included a definition of chorea and a description of choreic movements which the patients and members of their households were asked to read. Results were: 1) the only medical condition frequently reported was arthritis; 20/32 patients reported medical consultation for this complaint; 2) 19 patients including 2 with chorea gravidium, reported motor or psychiatric side effects from 1 or more agents; 3) in patients with multiple drug exposures a history of adverse motor reactions to decongestants was always associated with adverse reactions to anorectics or amphetamine in patients with exposure to all agents, and a similar pattern was noted with thyroid hormone and oral contraceptives (OCs); 4) 1 patient with chorea gravidium reported dyskinesias after administration of decongestants or amphetamine but tolerated OCs; and 5) MMPI scores from patients reporting adverse responses to amphetamines were statistically elevated in the psychotic tetrad. This study provides support for the belief that Sydenham's chorea is not a benign self-limited disease of childhood. In addition to mild residual neurologic abnormalities, the disorder appears to confer long-standing sensitivity to a variety of dopaminergically active agents.

Lipids of human milk and infant formulas: a review.

The amount of human milk ingested by the nursing infant is about 600 ml per day. The average lipid content of the mature ranges from 3.2 to 3.5% and the amount does not appear to be influenced by diet. About 98% of the lipid is triacylglycerol in which most of the secondary ester is palmitic acid, a unique structure possibly responsible for the relatively high absorbability of the fat. Small quantities of other lipids are present. Amounts of cholesterol reported, range from 200 to 564 mg per 100 g of lipid. While 167 fatty acids have been positively and tentatively identified as being present in human milk lipids, the major fatty acids are palmitic, stearic, oleic, and linoleic. The composition can be changed by diet, which linoleic acid contents of from 1.0 to 45.0% having been found. The "average" linoleic acid is about 10% and this amount is apparently adequate for the essential fatty acid requirements of the infant. The quantity of vitamin E also appears to be satisfactory. The hypothesis that a cholesterol challenge to the breast fed infant would enable the adult to more efficiently metabolize the sterol does not seem to be supported by available evidence, primarily, because the cholesterol content of human milks varies so markedly; 26 to 52 mg per 8 ounces. The compositions of most infant formulas currently in use in the United States are presented for comparison and convenience and a few possible problems associated with their consumption are discussed. We have suggested several areas where, in our opinion, additional research would provide useful information.