QT dispersion in the surface electrocardiogram in elderly patients with major depression.

BACKGROUND: QT dispersion (QTd) is a measure of interlead variations of QT interval of the surface 12-lead electrocardiogram (ECG). Increased QTd, found in various cardiac diseases, reflects cardiac instability and is associated with increased cardiac death. Major depressive disorder (MDD) was found to be associated with high cardiovascular mortality rates. This study compares QTd in elderly patients with MDD to normal controls. METHODS: QTd and rate-corrected QTd of 18 physically healthy elderly patients (69.9 +/- 7.6 years) with MDD was compared to nine physically and mentally healthy age- and gender-matched controls (64.1 +/- 12.2 years). RESULTS: QTd and rate-corrected QTd were significantly higher in MDD compared to controls (68 +/- 30 vs. 40 +/- 13 ms, P=0.002 and 81 +/- 39 vs. 43 +/- 13 ms, P=0.001, respectively). Intra- and inter- observer reproducibilities were highly correlated (r=0.96, P <0.0001; r=0.88, P <0.001, respectively). LIMITATIONS AND CONCLUSIONS: The major limitations of this study are the small number of subjects and the fact that all the patients were maintained on antidepressant medication. However, it seems that QTd analysis might shed light on possible autonomic imbalance and also provide a novel cardiovascular risk factor for increased cardiac death in MDD.

Are there circadian and circannual variations in acute toxicity of phenobarbital in mice?

The present work aims to document the possible influence of the time of the year on the circadian pattern of phenobarbital acute toxicity in mice by determination of phenobarbital acute toxicity at four different months of the year (i.e. October, January, April, and July). Our data indicate an important variation of phenobarbital acute toxicity throughout the year, with the maximum mortality occurring in January (i.e. minimum LD50) the minimum in July (i.e. maximum LD50). Thus, the season, not often taken into account, is an important determinant in toxicological studies.

Immunomodulatory activity of low doses of interferon alpha,beta in mice.

We evaluated the immunomodulatory effects of mouse interferon (IFN) alpha, beta on the specific humoral response of mice (OF1) to sheep erythrocytes and on cell-mediated immunity by studying the cytotoxic activity of allospecific T-cells (CTL) and natural killer (NK) cells. Four injections of 2 IU of IFN before administration of the antigen did not have an effect on the humoral response, whereas 4 injections of 2 x 10(-10) IU of IFN caused a significant increase in the number of antibody-secreting cells. When C57BL/6 mice were treated with 5 injections of 2 IU or 2 x 10(-10) IU of IFN before the second immunization with allogeneic cells, the CTL activity was not modified; but when the mice were also treated with 2 x 10(-10) IU 3 times after immunization, this activity was strongly stimulated. IFN caused a decrease in the activity of CTL from NZB at both doses. The cytotoxic response of NK cells was stimulated by 5 injections of 2 IU of IFN in both strains of mice. The results of our study suggest that very low doses of IFN alpha,beta have immunopharmacologic activity.

Behavioral effects of Euphorbia hirta L.: sedative and anxiolytic properties.

Lyophilised aqueous extract of Euphorbia hirta L. (Euphorbiaceae) has been evaluated for behavioral effects in mice. The extract did not induce any toxic effect when it was administered i.p. and orally. Sedative properties could be confirmed with high doses (100 mg of dried plant/kg, and more), by a decrease of behavioral parameters measured in non-familiar environment tests (activitest and staircase test), whereas anticonflict effects appeared at lower doses (12.5 and 25 mg of dried plant/kg), by an enhancement of behavioral parameters measured in the staircase test and in the light/dark choice situation test. These findings validate the traditional use of E. hirta as a sedative and reveal original anxiolytic properties.

Timing and anticipation.

The present study examined the development of timing and coincident anticipation, whereby subjects moved a slide control to direct a cursor to intercept a target. An equal number of males and females (N=120 each) comprised the following age groups: 6-7, 8-9, 10-11, 12-13, 14-15, and 18-19 yr. Age, sex, and trials constituted the independent variables, with dependent measures of absolute, constant, and variable error. Each person completed60 trials, with complete target view present in the first 40 trials. The target disappeared from view shortly after initial movement in Trials 41-60. Each older age group performed, with less error than the next younger age group, with the exception of the equal skill level of the two oldest groups. Males outperformed females, and target masking resulted in significant decrements in performance. Information processing mechanisms that may be responsible are discussed.

Recall and recognition processes in motor memory: effects of feedback and knowledge of results delay.

In linear movement tasks of 200 msec (Experiment 1 -ballistic movement) and 500 msec (Experiment 2 - nonballistic movement), motor recall strength was assessed by absolute, constant, and variable error; recognition strength was assessed by Z'-transformed actual-estimate correlations and absolute actual-estimate difference scores. Contrary to predictions, neither increased KR delay (45 vs. 5 sec) nor limited visual-auditory-tactile feedback caused decrements in recognition processes over KR-training or KR-withdrawal trial blocks for the 200-msec task. In the 500-msec task, the independent variables impaired recognition through training and transfer trials but impaired recall only in the training trials. Results generally did not support the hypothesized independence between recall and recognition processes. Several methodological issues related to recall, and recognition research were discussed.

The effects of task coherency, preview, and speed-stress on timing and anticipation.

High levels of skill displayed in perceptual-motor tasks can only be obtained by accurate timing and anticipation. Recent evidence indicates that task characteristics that change or alter the predictability of stimulus events are potent determiners of performance. The effects of stimulus predictability on timing and anticipation were investigated in a series of studies where subjects responded to moving stimuli that entered critical zones on each of three visual displays. Specific task characteristics that changed the predictability of the stimulus sequence and significantly affected performance in the studies included task coherency, preview, speed-, and load-stress.

Substitutes for leadership: test of a construct.

The study reported here examined the impact of leadership substitutes on subordinate job satisfaction and organizational commitment. Leadership substitutes, as suggested by Kerr (1977), replace or "act in the place of" a specific leader behavior. Multiple regression was used to test the validity and strength of potential substitutes. Results indicated mixed support for the substitutes construct.

Leadership and substitutes for leadership among professional and nonprofessional workers.

In this article, the authors discuss their research on similarities and differences between professionals and nonprofessionals in their responses to managerial leadership behaviors and substitutes for leadership. Their study sample comprised workers at many organizational levels in several hospital and contract research organizations in the Southwest, and they used a multidimensional measure of professionalism to create subsamples of professionals and nonprofessionals. The authors used questionnaire data to test hypotheses regarding instrumental and supportive leadership behaviors and their substitutes. They found that role clarification and support from leaders were important predictors of worker's job satisfaction and organizational commitment for both subsamples, and that formal rules and procedures were an important supplement for instrumental leadership behaviors. Professionals differed from nonprofessionals in that intrinsically satisfying work tasks and importance place on organizational rewards were strong substitutes for leaders' support. The authors conclude that worker professionalism is an important moderator variable for research on leadership and substitutes for leadership.

Analgesic, antipyretic and anti-inflammatory properties of Euphorbia hirta.

Lyophilised aqueous extract of Euphorbia hirta L. (Euphorbiaceae) has been evaluated for analgesic, antipyretic and anti-inflammatory properties in mice and rats, in order to complete its activity profile, after the confirmation of the existence of a central depressant activity particularly expressed by a strong sedative effect, associated with anxiolytic effects. This study leads us to the conclusion that this plant extract exerts central analgesic properties. Such a dose-dependent action was obtained against chemical (writhing test) and thermic (hot plate test) stimuli, respectively, from the doses of 20 and 25 mg/kg and it was inhibited by a naloxone pretreatment, a specific morphinic antagonist compound. An antipyretic activity was obtained at the sedative doses of 100 and 400 mg/kg, on the yeast-induced hyperthermia. Finally, significant and dose-dependent anti-inflammatory effects were observed on an acute inflammatory process (carrageenan-induced edema test in rats) from the dose of 100 mg/kg. On the other hand, plant extract remained inactive on chronic processes such as Freund's adjuvant-induced rheumatoid arthritis, after a chronic treatment during fourteen days at the daily dose of 200 or 400 mg/kg; however, if inefficacy was observed on rat backpaws edema and on loss of weight, the aqueous extract reduced the inflammatory hyperalgia.

tert-Butyl hydroperoxide-induced injury in isolated rat hepatocytes: a model for studying anti-hepatotoxic crude drugs.

Tert-butyl hydroperoxide induces in freshly isolated rat hepatocytes malonaldehyde formation and lacticodehydrogenase and aspartate amino-transferase leakage. This model, when adapted to crude extracts, permits the demonstration of both anti-lipoperoxidant and antihepatotoxic activity of reference products like quercetin and silymarin and plant extracts like Rosmarinus officinalis and Eschscholzia californica.

Buflomedil kinetics in patients with liver disease.

The pharmacokinetics of single intravenous (100 mg) and oral (450 mg) doses of buflomedil was studied in 3 and 6 patients respectively, suffering from chronic liver disease. Comparisons of buflomedil kinetic parameters between the patients and healthy subjects indicate a significant increase in AUC0 infinity, T beta, u' and a significant decrease in Cle', Clnr when the patients received the oral dose, but no significant differences when the patients received the intravenous dose probably due to the small number of patients explored. The elimination of buflomedil is impaired in chronic hepatic disease. It seems advisable to reduce the usual dose to half its value when the prothrombin index is around 50% associated with a low albumin concentration and a low factor V.

Ileus post-operatoire et homeopathie: bilan d'une evaliation clinique / Ileus post operatory and homeopathy

L'ileus post-operatoire est un motif de plainte tres souvent allegue par les patients a la suite d'une laparotomie. Les symptomes fonctionnels qui lui sont associes... (AU)