Ascorbic acid increases synaptosomal potassium-induced dopamine release

On synaptosomes prepared from striata of mice, increasing concentrations of ascorbic acid (from 0.01 mM to 0.5 mM) did not modify the 3H-dopamine uptake. However, at the 0.1 mM concentration, ascorbic acid increased the potassium-induced release of 3H-dopamine by synaptosomes previously loaded with the amine. This effect was dependent on the presence of Ca2+ in the superfusion medium and was not shared by dehydroascorbic acid (from 1 mM to 0.01 mM). This effect of ascorbic acid, which occurs in the range of its endogenous concentrations, suggests that it is a putative modulator of dopaminergic transmission.     

Assessment of alcohol consumption and alcoholism in the elderly

This study evaluates characteristics associated with alcohol consumption or alcohol-related problems in an elderly population, as detected by CAGE questionnaire and self-reported alcohol intake respectively. Data were obtained from a multidimensional study carried out in a community-dwelling population aged 70-75 (n = 1205, 389 males and 816 females) living in the city center of Brescia, in northern Italy. All information was gathered by self-report. Male gender, better mood, daily function, somatic health, not living alone, and being married were significantly associated with self-reported alcohol consumption. Male gender, poorer cognitive function, and income dissatisfaction were significantly associated with alcohol problems as detected by CAGE. Data suggest that self-report of alcohol intake, though intrinsically loaded with imperfect internal consistency, does not necessarily indicate risk of alcoholism; on the contrary, it can reveal the positive psychological attitude of the drinking habit. CAGE questionnaire, which is sensitive to alcohol related problems, is associated with poor psychosocial conditions.     

Rhodopsin mutations in autosomal dominant retinitis pigmentosa

Retinitis pigmentosa is an inherited progressive disease which is a major cause of blindness in western communities. It can be inherited as an autosomal dominant, autosomal recessive, or X-linked recessive disorder. In the autosomal dominant form (adRP), which comprises about 25% of total cases, approximately 30% of families have mutations in the gene encoding the rod photoreceptor-specific protein rhodopsin. This is the transmembrane protein which, when photoexcited, initiates the visual transduction cascade. So far, 41 single-base-pair (bp) substitutions, one two-bp substitution, and four deletions ranging from 3 to 42 bp have been identified in this gene. These mutations do not appear to be significantly clustered in a specific part of the protein, but occur in all three major domains, namely the intradiscal, transmembrane, and cytoplasmic regions. Different mutations appear to cause differences in the severity of the disease, though there is considerable variability in severity even within the same family, at least in certain of these mutations. Identification of all the mutations involved in rhodopsin-RP should allow accurate and early detection of affected individuals, informed genetic counselling, as well as furthering our knowledge of the disease process involved.     

Value of early variables as predictors of short-term outcome in patients with acute focal cerebral ischemia

The pathogenesis of essential thrombocythemia as a clonal myeloproliferative disorder has been clearly established. However, there continues to be considerable controversy concerning the management of this disease, particularly because its natural history is consistent with a nearly normal life expectancy. Therapeutic decisions have been complicated by a reliance on largely anecdotal, retrospective experience in the medical literature and, until very recently, an absence of prospective, controlled clinical trials. A recent study of patients with essential thrombocythemia at high risk of thrombosis because of advanced age or previous history of thrombotic complications demonstrated that platelet cytoreduction with hydroxyurea is effective in reducing thrombotic complications. Other cytoreducing agents that have been used in this disease include alkylating agents, recombinant interferon alpha, and anagrelide. The use of antiplatelet therapy is also controversial, and is most highly effective in patients with digital or cerebrovascular ischemic problems.     

Modeling and design of an AC to DC converter

A step-up/down single-phase AC-to-DC power converter without current sensor is proposed to achieve high performance and simple control logic. The power converter adopts a front-end diode rectifier so that only one active switch is required. The familiar state-space averaging technique for discontinuous mode DC-to-DC power converters is extended to model the proposed AC-to-DC converter. Unlike the existing model, which is valid only for a very low frequency range, namely below line frequency, the proposed model is applicable up to half switching frequency. The design of the controller is detailed. Selected experimental results are presented to verify the proposed theory     

Aneurysms of splanchnic arteries

Aneurysms of splanchnic arteries represent an uncommon but important vascular disease, which many times presents itself as clinical emergency and often results in death. 11 patients with splanchnic aneurysms were treated in our Department during the last 15 years. These aneurysms were located in 5 cases in splenic artery, 4 cases in hepatic artery, 1 case in celiac axis and 1 case in right gastroepiploic artery. Surgical treatment of these aneurysms was successful in all but one patient (he died from rupture of a hepatic artery aneurysm). Giving an overall mortality similar to that reported in the literature. The treatment of these aneurysms is discussed, while literature about this uncommon disease is reviewed.     

Staging of pulmonary apex tumors. Computerized tomography versus magnetic resonance

In an experiment designed to distinguish between the behavioral consequences of treatment with SCH-23390, a D1 dopamine receptor blocker, and raclopride, a D2 antagonist, rats were trained to perform a water-reinforced forelimb operant response. Response rate and the duration of each forelimb contact with the operandum were recorded. In addition, the durations of the rat's visits to the reward well were detected by a photobeam which was blocked by the rat's muzzle as it remained at the reward well. In a between-groups dosing design, separate groups of rats (11-13 rats/group) received SCH-23390 (0, 0.01, 0.02, 0.04, 0.08, 0.12 mg/kg, IP, 30 min) or raclopride (0. 0.05, 0.1, 0.2, 0.4, 0.8 mg/kg, IP, 30 min) for 21 consecutive days. Quantitative analyses indicated that for comparable amounts of operant rate reduction, raclopride had a significantly greater tendency than SCH-23390 to increase the duration of operant responses and to increase the maximum muzzle entry duration (i.e., to induce microcatalepsy). The results support the idea that at relatively low doses D2 antagonism is more likely than D1 antagonism to produce effects identified preclinically with extrapyramidal side effects.