Dietetics students perceive themselves as leaders and report they demonstrate leadership in a variety of contexts

A leadership survey was designed and administered to undergraduate dietetics students (n=283) at eight universities to examine leadership actions reported most frequently, the context of these leadership actions, and students' reported perceptions of themselves as leaders. The majority of students perceive themselves as leaders in all context areas. The leadership practice, "Enabling Others to Act," was the most frequently reported. There were no significant differences in leadership behaviors based on college classification status and supervisory experience. Leadership behaviors were more prevalent in students who had previous leadership course-work, were older, or who had previous leadership experience. Dietetics students perceive they demonstrate leadership and do so in a variety of contexts, most frequently in class. Therefore, classroom activities may help strengthen leadership abilities of future dietetics professionals.     

Single-dose kinetics of oral propranolol, metoprolol, atenolol, and sotalol: relation to lipophilicity

Nine healthy volunteers received single oral doses of the following four beta-adrenergic blocking agents: propranolol (160 mg), metoprolol (100 mg), atenolol (200 mg), and sotalol (320 mg). The kinetics of each drug were determined from multiple serum concentrations measured during 24-48 h after each dose, and in vitro lipid solubility determined using the liquid chromatographic (HPLC) retention index. Oral clearance for the four drugs ranged from 40.2 ml/min/kg for propranolol down to 2.1 for sotalol. Oral clearance was highly correlated (r = 0.99) with in vitro lipid solubility, with propranolol being the most lipophilic drug and sotalol the least. Thus lipophilicity is a physicochemical property of beta-adrenergic blockers that appears to influence their intrinsic clearance after oral dosage.     

Inducible neuronal expression of transgenic TGF-beta1 in vivo: dissection of short-term and long-term effects

Various chronic neurological diseases are associated with increased expression of transforming growth factor-beta1 (TGF-beta1) in the brain. TGF-beta1 has both neuroprotective and neurodegenerative functions, depending on conditions such as duration and the local and temporal pattern of its expression. Previous transgenic approaches did not enable control for these dynamic aspects. To overcome these limitations, we established a transgenic mouse model with inducible neuron-specific expression of TGF-beta1 based on the tetracycline-regulated gene expression system. TGF-beta1 expression was restricted to the brain where it was particularly pronounced in the neocortex, hippocampus and striatum. Transgene expression was highly sensitive to the presence of doxycycline and completely silenced within 6 days after doxycycline application. After long-term expression, perivascular thioflavin-positive depositions, formed by amyloid fibrils, developed. These depositions persisted even after prolonged silencing of the transgene, indicating an irreversible process. Similarly, strong perivascular apolipoprotein E (ApoE) depositions were found after TGF-beta1 expression and these remained despite TGF-beta1 removal. These in vivo observations suggests that the continuous presence of TGF-beta1 as initial trigger is not necessary for the persistence and development of chronic lesions. Neuroprotective effects were observed after short-term expression of TGF-beta1. Death of striatal neurons induced by 3-nitropropionic acid was markedly reduced after induced TGF-beta1 expression.     

Psychomotor slowing in hepatitis C and HIV infection

BACKGROUND: Both HIV and hepatitis C virus (HCV) may enter the central nervous system and cause cognitive and/or motor dysfunction. There are limited data on cognition and no data on motor performance in HIV/HCV-coinfected patients. OBJECTIVE: To provide data on cognition and motor performance in HIV/HCV infected patients. METHODS: We compared 43 HIV-seropositive but HCV-seronegative patients, 43 HIV/HCV-coinfected patients, and 44 HIV-negative but HCV-positive patients, all of whom went through neuropsychologic testing and electrophysiologic assessment of basal ganglia-mediated motor function. RESULTS: No significant differences could be found among the groups with regard to premorbid verbal and actual nonverbal intelligence, attention, and memory; the HIV dementia scale; and all somatic and most psychiatric complaints. Affective disorders were less frequent in HIV-negative but HCV-positive patients. This group also scored lower for depression. For all 3 groups, significant pathologic slowing of most rapid alternating movements (right hand) compared with those of HIV/HCV-negative controls as well as significantly prolonged contraction times (both hands) could be diagnosed. Simple reaction times were significantly prolonged only in HIV/HCV-coinfected patients. CONCLUSIONS: Although clinically asymptomatic, both HIV-positive and HCV-positive patients may show affective disturbances and significant psychomotor slowing. A potential predictive value for the further course of infection, which is well established in HIV-positive patients, remains to be investigated in HCV-positive or HIV/HCV-coinfected patients.     

Detection of nitric oxide synthase (NOS) immunoreactive neurons in the human septal area: a matter of method?

There is a remarkable discrepancy between biochemical and cell morphological findings with regard to the presence of NADPH diaphorase/neuronal nitric oxide synthase (NOS) in the primate septal area. Whereas considerable concentrations of neuronal nitric oxide synthase and high enzyme activities have been measured in postmortem human septal nuclei, histochemical studies were either unable to detect any nitric oxide synthase immunoreactivity in primate septal neurons, or found only a very few nitrergic neurons in this region. This study aimed to investigate the possible presence of nitrergic neurons in human the septal region in greater detail. After having studied a total of 16 postmortem human brains we conclude that the immunohistochemical demonstration of nitric oxide synthase in human septal neurons is largely dependent on the mode of tissue handling: in brain specimens which were fixed en-bloc with paraffin and embedded in paraplast, nitric oxide synthase immunoreactivity is barely detectable, whereas a satisfying immunostaining is obtained on free-floating frozen sections after an immersion–fixation with 4% paraformaldehyde and 0.5% glutaraldehyde, followed by sucrose protection of the specimens. We show herein that there are indeed nitric oxide synthase-containing neurons in the human septum, thus supporting results from previous biochemical studies.