Inhibitory and facilitatory effects of cue onset and offset

The response speed to a visual target is modulated by the position of previous events (cues) even if their position is not predictive of the target position. The modulation has been considered biphasic, with an early facilitatory and a later inhibitory component. We conducted three experiments that investigated the importance of the onset and offset features of the cue for the facilitatory and inhibitory effects and estimated their separate and joint effects. The two possible target locations, one in the right and one in the left visual field, were indicated by two empty boxes, and the cue consisted of the onset and/or offset of an arrowhead located just under one of the two boxes. Different time intervals were used between cue and target. Subjects were instructed to ignore the cue and to respond to the target (a cross inside one of the two boxes). The data showed only consistent effects of inhibition (inhibition of return) with the long intervals, but the pattern was different depending on the cue type. The amount of inhibition was much greater when the onset of the cue was followed by its offset. Apparently, inhibition of return depended on the dynamic changes of the cue.

Calcium antagonist properties of the bisbenzylisoquinoline alkaloid cycleanine

The alkaloid cycleanine ([12aR-(12aR,24aR)]-2,3,12a,13,14,15,24,24a-octa hydro-5,6,17,18- tetramethoxy-1,13-dimethyl-8, 11:20,23-dietheno-1H,12H [1,10]dioxacyclooctadecino[2,3,4-ij:11,12,13-i'j']diisoquinolin e) was extracted from the bulbs of Stephania glabra (Roxb) Miers and its effects on cardiac and smooth muscle preparations were studied and compared to those of nifedipine (1,4-dihydro-2, 6-dimethyl-4-(2-nitrophenyl)-3,5-pyridine dicarboxylic acid dimethylesther). Cycleanine inhibited the KCl-induced contraction of rabbit aortic rings with higher potency than nifedipine. IC50s for cycleanine and nifedipine were 0.8 and 7.10(-9) M respectively. Cycleanine had minor effects on the norepinephrine-induced contraction of rabbit aortic rings. Cycleanine and nifedipine also depressed the contraction of rat ventricular preparations but with lower potency (IC50 = 3 and 0.03.10(-6) M respectively). Action potential duration of rat right ventricular strips was decreased by both compounds. L-type Ca-current (ICaL) of single rat ventricular cardiomyocytes was inhibited by cycleanine in a voltage- and frequency-dependent manner. With a higher potency nifedipine inhibited ICaL in a tonic and almost frequency-independent manner. The results suggest that cycleanine can act as a potent vascular selective Ca-antagonist.

Characterization of the atherosclerotic plaque in the internal mammary artery

The current study examines, at both structural and ultrastructural levels, representative segments of internal mammary arteries obtained from 15 male patients, ranging in age from 45 to 75 years, with signs or symptoms of coronary heart disease. These segments were obtained at the time of coronary bypass surgery. Of the 15 segments examined, only 2 were found to have atherosclerotic plaques. In other segments, only an intimal thickening similar to that observed during aging was found. There was evidence of endothelial cell loss and defects of internal elastic lamina in the present study; however, there was no evidence of lipid accumulation in the intimal region. This observation agrees with previous findings that indicate that lipid accumulation is not a necessary factor for the formation of atherosclerotic plaques. During the study microfilament bundles, the so-called "stress fibers," were also observed in the cytoplasm of the luminal side of endothelial cells. Stress fibers are known to be present in some endothelial cells in some pathologies such as regeneration after injury or hypertension. One of the features of the atherosclerotic plaques from an internal mammary artery was the presence of cells with contractile and synthetic phenotypes (contractile and synthetic smooth muscle cells), as well as cells with intermediate features. Cells with similar characteristics have also been observed during the development of the early stages of atherosclerosis, during embryological development of vessels, after experimental excimer laser treatment, and in primary cell culture. To our knowledge, this is the first report showing the ultrastructural features of the atherosclerotic plaques in the internal mammary artery.

A review of esthetic alternatives for the restoration of anterior teeth

PURPOSE

This article describes different options for the esthetic treatment of anterior teeth, starting with minimally invasive procedures, such as facial surface bleaching and bonding with composites.

METHODS

The importance of metal ceramic restorations, porcelain shoulder techniques, and metal free ceramics are also emphasized. The options are carefully demonstrated to identify advantages and limitations of each technique.

Metabolism of (-)-(S)-nicotine in the isolated perfused rabbit lung

The metabolism of (-)-(S)-nicotine has been investigated following intratracheal administration to the recirculating perfused rabbit lung model. The metabolic products present in the perfusate were identified by co-chromatography (HPLC and GC) with authentic standards and quantified by HPLC. After the 180 min perfusion period, nicotine was found to be metabolically transformed to cotinine (33.7%), 3-hydroxycotinine (10.4%), cotinine-1-N-oxide (3.4%) and nicotine-1'-N-oxide (14.4%). Norcotinine, nornicotine, 3-pyridyl-4-oxo-N-methylbutyramide and an uncharacterised metabolite were also detected in low amounts. Following the perfusion experiment, part of the lung tissue was homogenised in the presence of [14C]-sodium cyanide. Subsequent analysis of the homogenates indicated the formation of 2'-cyanonicotine, 1'-cyanomethylnornicotine and the diastereoisomeric 5'-cyanonicotines.

[Antibiotic pretreatment of heart valve prostheses]

Bacterial endocarditis on cardiac valvular prosthesis is still a frequent and dangerous complication: septicemia, embolism, valvular dysfunction and mortality. To prevent these complications, intraoperative treatment of prosthesis, by immersion in antibiotic solution, was performed in 1262 patients. The postoperative results have been compared with results of a nontreated group. The incidence of endocarditis in the treated group was 1.3%, in non-treated cases 5.45%. The cases of early endocarditis, was 0.08% of total cases of complications in the treated patients group; and 4.54% in the nontreated patient group. This study's results, confirm the utility of valvular prosthesis antibiotic treatment in cardiac surgery.

Phase II study of the therapeutic efficacy and safety of the new antimycotic sertaconazole in the treatment of superficial mycoses caused by Candida albicans

The activity of 7-chloro-3-[1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethoxy-methyl] benzo[b]thiophene (sertaconazole, FI-7045, CAS 99592-32-2) was studied in a randomized parallel double-blind clinical trial on 20 patients suffering from superficial mycosis caused by Candida albicans (confirmed microscopically and microbiologically). The patients were divided into two groups; one received sertaconazole 1% cream (10 patients) and the other received sertaconazole 2% cream (10 patients), over a period of 28 days. Clinical, microscopic and microbiological parameters were evaluated. Analytical parameters such as the appearance of possible undesirable effects (both local and general) were also monitored. The cure was total for 19 out of the 20 patients, demonstrating high efficacy. There were no relapses of infection in any of the cured patients. No local or general effects were recorded during the trial. The analytical parameters remained within normal limits. The clinical and microbiological cure, absence of relapses and the non-existence of local and general undesirable effects indicate that sertaconazole may represent an important advance in the therapy of superficial mycosis caused by Candida albicans.

[Effectiveness of topical selective decontamination, without systemic antibiotic prophylaxis, in prevention of pulmonary infection in intensive care]

Forty-seven patients admitted in our general ICU and treated with Selective Digestive Decontamination (SDD) without any systemic antibiotic prophylaxis, were prospectively studied and compared with an historical group of 50 non treated subjects. The 2 groups were no different as to underlying disease, age, sex and prognostic index (SAPS). In the treated group was recorded an important and statistically significant reduction in the incidence of pneumonia and in the frequency of pulmonary infections caused by enterobacteriaceae and pseudomonceae. Gram-positive identification in tracheal aspirates was not significantly different in the two groups as well as the incidence of "early pneumonia". In the treated group, a sharp decrease of the total amount of fever-days through ICU stay was observed. The antibiotic consumption resulted to be an overall 28.3% lower in the group treated with, SDD with particular regard to broad-spectrum ones.

[Iatrogenic disease in hemophilia and Von Willebrand's disease]

From a group of 115 children with hereditary haemorrhagic disease, nine suffered avoidable accidents or incidents during their treatment, these nine patients represent 8.6% of the cases. The observed complications included a giant cervical hematoma and hemomediastinum after a puncture of the internal jugular vein; an encephalic lesion associated with descompressive craneotomy; a hemophilic pseudo cyst associated with inappropriate treatment of a tibial fracture; acute bleeding and shock after surgery for tonsillectomy and circumcision; subdural hygroma after a subdural puncture; giant hematoma and acute anemia secondary to a venous dissection; permanent dyslexia after inappropriate puncture; giant hematoma and acute anemia secondary to a venous dissection; permanent dyslexia after inappropriate management of intracranial bleeding; bleeding and acute anemia after surgical drainage of a prepucial hematoma and a joint hematoma of the left knee after synovectomy and application of a prosthesis.

Effect of 4-aminopyridine on cardiovascular functions in the dog

The drug 4-aminopyridine (4-AP) at a dose of 0.2 mg . kg-1 body weight intravenously is an effective antagonist of non-depolarizing neuromuscular blockade. We studied its cardiovascular effects in the canine heart using a right-heart bypass with extracorporeal circulation in seven dogs. This study demonstrates that 4-aminopyridine significantly augments arterial blood pressure, left ventricular dp/dt maximum, as well as left ventricular pressure at dp/dt mx. The highest values were obtained between two and 20 minutes after administration of 4-AP. Left ventricular end-diastolic pressure diminished slightly, but this was not statistically significant. Although the exact mechanism of action of 4-AP is not known, its positive inotropic effects may be of value in the reversal of non-depolarizing neuromuscular blockade in patients with impaired myocardial function of diverse aetiologies and it would be contra-indicated in patients with arterial hypertension and/or coronary artery disease.

[Radical correction of the tetralogy of Fallot: 122 cases]

In 122 patients with Fallot tetralogy total correction was performed. 18 were previously operated with palliative surgery. The results were the following: hospital mortality: 8,5%; very good or good improvement: 78%; satisfactory in 13,5%.