Interference between concurrent tasks of driving and telephoning.

224 men were given the task of judging whether to drive through gaps which might be larger or smaller than the car, and a telephoning task of checking the accuracy of short sentences. Interference between the concurrently performed tasks was investigated. Telephoning mainly impaired judgments of "impossible" gaps. The control skills employed in steering through "possible" gaps were not reliably degraded, although speed of driving was reduced. Driving increased errors and prolonged RTs on the sentence-checking task. It is concluded that telephoning has a minimal effect on the more automatized driving skills, but that perception and decision-making may be critically impaired by switching between visual and auditory inputs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of ketamine on canine cardiovascular function

Left ventricular contractility was assessed before and during the peak effect of ketamine in eight canine right heart bypass preparations. Myocardial contractility was defined in terms of maximum left ventricular dp/dt, the ejection fraction, and left ventricular end-diastolic and left atrial pressures at constant heart rate and cardiac inflow. Ketamine produced significant decreases in contractility and there were some indications of a dose-response pattern. The action of ketamine was dependent partly on changes in arterial pressure, as the drug caused a mild but sustained vasodilatation which was not dose-dependent. These data offer further evidence of a small and transient negative inotropic effect of ketamine.     

Effects of caffeine on alertness in simulated automobile driving.

30 min after ingesting 200 mg of caffeine or a placebo, each of 24 21-26 yr old males drove an automobile simulator for 90 min. Immediately thereafter, the S ingested a supplemental dose of 200 mg of the medication taken initially and then drove for another 90 min. The simulator provided a comprehensive and coherent set of stimulus inputs which produced a degree of realism not usually found in laboratory studies. Both the initial and the supplemental doses of caffeine significantly enhanced performance beyond that found with placebo, on each of 4 measures of alertness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of level of processing on implicit and explicit tasks.

Replicated, in a series of experiments, the interaction that B. H. Challis and D. R. Brodbeck (see record 1992-30007-001) reported between list design (blocked or mixed) and level of processing for word fragment completion: The advantage for semantically processed words over shallowly processed words was greater when the conditions were blocked than when they were mixed on the study list. A similar interaction was found for perceptual identification (a data-driven implicit task) and priming in general knowledge questions (a conceptually driven implicit task). However, both data-driven and conceptually driven explicit tasks failed to reveal such a pattern. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of orienting tasks on the retention of prose material.

Two studies investigated the effects of orienting tasks on retention of prose material. Exp I, with 200 undergraduates, assessed several such tasks under incidental and intentional instructions. Dependent variables were recall and recall per unit time (efficiency). Outlining and copying tasks generated good recall that forced more interaction with the material. A sorting task affected the quality of interaction with material. Exp II, with 280 undergraduates, investigated the effects of different strengths of instructions. Strong instructions induced more interaction, resulting in better recall under intentional than under incidental instructions. Intentional instructions had greater impact on less efficient tasks and less effect on more efficient tasks. Maximum recall and efficiency occurred with simple instructions to read the passage. An activity or levels of processing hypothesis is proposed. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chronotherapeutics for cardiovascular disease

Chronotherapeutics, or delivery of a medication in concentrations that vary according to physiological need at different times during the dosage period, is a relatively new practice in clinical medicine. Epidemiological studies document that the incidence of many cardiovascular diseases, including myocardial infarction and stroke, varies predictably in time over 24 hours (the circadian period). Advanced diagnostic technologies using ambulatory monitoring of the blood pressure and electrocardiogram have also demonstrated that there is marked variability in the level of pressure in hypertensive patients and the degree of myocardial ischaemia in patients with coronary disease. These diagnostic techniques also allow us to study the effects of varying the timing of administration or delivery of a concentration of a drug on end-points such as changes in blood pressure, heart rate or intensity of angina. The first chronotherapeutic agent for hypertension and angina pectoris, controlled onset, extended release (COER-24) verapamil, has recently been developed and registered in the US, Brazil, Canada and Mexico. The theoretical advantage of this formulation is that delivery of the active drug, verapamil, has been tailored to the typical circadian rhythm of blood pressure and heart rate in patients with hypertension and angina to better cover the early morning hours when cardiovascular need appears to be the greatest. An outcome study (CONVINCE) that evaluates primary prevention of cardiovascular events with this chronotherapy versus standard of care therapy is under way in several countries in North and South America and Europe.     

Thrombosis and cardiovascular disease

The use of combinatorial chemistry for the generation of new lead molecules is now a well established strategy in the drug discovery process. Central to the use of combinatorial chemistry is the design and availability of high quality building blocks which are likely to afford hits from the libraries that they generate. Herein we describe "RECAP" (Retrosynthetic Combinatorial Analysis Procedure), a new computational technique designed to address this building block issue. RECAP electronically fragments molecules based on chemical knowledge. When applied to databases of biologically active molecules this allows the identification of building block fragments rich in biologically recognized elements and privileged motifs and structures. This allows the design of building blocks and the synthesis of libraries rich in biological motifs. Application of RECAP to the Derwent World Drug Index (WDI) and the molecular fragments/ building blocks that this generates are discussed. We also describe a WDI fragment knowledge base which we have built which stores the drug motifs and mention its potential application in structure based drug design programs.     

Hyperlipidaemia and cardiovascular disease

OBJECTIVE: The aim of the study is to investigate the relationship between urinary cytology, traditional indexes of malignancy of bladder carcinoma and DNA-ploidy (diploid, near-diploid, aneuploid). METHODS: 52 specimens of bladder cancers (transitional cell carcinoma) were obtained from 46 patients at TURB and from 6 patients at radical cystectomy. In every specimen the nuclear content of DNA was investigated using the cytofluorimetric method. Cells were processed in standard fashion for flow cytometry with propidium iodide staining; cellular suspension was obtained mechanically. Peripheral blood lymphocytes were used as diploid standard. Bladder cytology was performed in every patient. RESULTS: A relationship between DNA-ploidy and histological malignancy was observed. The largest portion of near-diploid neoplasm was observed in stage T1, grade G2 malignancies. In some cases negative bladder cytology occurred together with aneuploid DNA content, whilst in other cases positive bladder cytology occurred together with diploid DNA content. In consequence there is not always a relationship between bladder cytology and DNA-ploidy. CONCLUSIONS: Since observed correlations may point out some neoplasms with particular biological behaviour, follow-up of near-diploid malignancies is of great interest.     

Autonomic assessment of cardiovascular disease

Port wine stains (PWS) can lead to considerable emotional distress. The present study evaluated a) the coping with illness, the quality of life and the body image of patients with PWS and b) the effects of dye laser treatment on psychosocial parameters. Seventy PWS patients undergoing treatment with the flashlamp-pumped pulsed dye laser (FPDL) were assessed with questionnaires regarding coping with skin disease, quality of life and body image. Major clinical criterium was the lightening of PWS under treatment. PWS patients showed significant social phobia and avoidance similar to patient suffering from chronic skin diseases. The anxiety correlated with size and darkness of the PWS. In terms of helplessness and depressive mood, PWS patients were less affected than the comparison group. Also, PWS patients had reductions in quality of life and in body image. The coping strategies had a differential effect on the body image. Since there is a correlation between lightening of the PWS and reduction of emotional distress, FDPL therapy can be considered an effective treatment of PWS also in psychosocial terms.     

Attention and driving performance in Alzheimer's disease

The present study examined the relationship between visual attention measures and driving performance in healthy older adults and individuals with very mild and mild dementia of the Alzheimer type (DAT). Subjects were administered an on-road driving assessment and three visual attention tasks (visual search, visual monitoring, and useful field of view). The results indicated that error rate and reaction time during visual search were the best predictors of driving performance. Furthermore, visual search performance was predictive of driving performance above and beyond simple dementia severity and several traditional psychometric tests. The results suggest that general cognitive status may be useful for identifying individuals "at risk" for unsafe driving. However, measures of selective attention may serve to better differentiate safe versus unsafe drivers, especially in the DAT population.     

Effects of wearing compression stockings on cardiovascular responses

To investigate the effects of wearing compression stockings on cardiovascular responses, the heart rate (HR), cardiac output (Q) measured by CO2 rebreathing method, and oxygen intake were measured at rest in a supine position for 40 min and standing position for 120 min. Six female subjects wore the compression stockings after 20 min of rest at supine position. The oxygen intake and ventilation showed no significant difference between with and without the stockings. Q at standing position was lower than that at supine position by an act of hydrostatic pressure. However this decrease was lower with stockings than that without stockings. The compression stockings used in this study might improve the venous return to the heart. However, the subjects complained of discomfort due to the high clothing pressure. In the second experiment, the authors estimated the minimum pressure required in improving the venous return. The subjects wore the trousers having two bladders inflated by air pressure. The trousers could compress the leg (contain the foot) and thigh individually. From the relationship between air pressure and Q, the estimated minimum pressures were 17 mmHg for the leg and 15 mmHg for the thigh.     

Aspirin therapy for cardiovascular disease

Bone densitometry has become a major tool for osteoporosis risk assessment. The traditional dual-energy X-ray absorptiometry (DXA) methods are able to evaluate the bone mineral content (BMC; mg/cm) and the areal density (BMD; mg/cm2), but only quantitative computed tomography (QCT) has the potential to measure the true volumetric bone density in the sense of mass per unit volume (mg/cm3). Peripheral QCT (pQCT) measurements were carried out at the nondominant radius using a Stratec XCT 960 (Unitrem, Roma) in 241 postmenopausal and 29 premenopausal women. The sites of evaluation were both the ultradistal and the proximal radius. The technique used has a coefficient of variation of 2% and it allows separation of the bone section into trabecular and cortical bone on the basis of density threshold. Bone mass of radius, hip and spine was also evaluated by DXA procedures. The bone density data obtained by pQCT were significantly correlated with all DXA measurements. The correlation coefficients between their respective BMD values ranged from 0.48 to 0.75, but for the BMC values of the radius the correlation coefficients ranged from 0.82 to 0.93. The BMD values measured by DXA, but not by pQCT, were positively related with patient heights. All pQCT density measurements, including those obtained at the proximal radius and containing exclusively cortical bone, where negatively related with age and years since menopause. A partial volume effect, which is increasingly relevant the thinner are the bone cortices, might explain that. However, by applying increasing density thresholds, cortical bone density seems to decrease with age as a consequence of a gradual density diminution from the inner part of the bone cortex outwards. Trabecular bone density decreases with aging, but its overall mass does not change as a consequence of an age-related enlargement of trabecular area. Thus, the proportion of trabecular bone over total bone rises, and this might be relevant for our understanding of the age-related changes in bone turnover and rate of bone loss.     

Chlamydia pneumoniae and cardiovascular disease

Oculomotor organization in elasmobranch fish (sharks, skates, and rays) differs from that in other vertebrates in that the medial rectus muscle is innervated by contralateral rather than ipsilateral motoneurons. Distinguishing whether this innervation pattern is unique to the elasmobranchs, or is the ancestral pattern for cartilaginous fishes, requires examination of a representative of the sister group to the elasmobranchs, the holocephalans (ratfish). In the present study, the innervation pattern of the medial rectus was examined in a ratfish, Hydrolagus colliei, by using biotinylated dextran amines (BDA, 3,000 MW). Labeled cells were revealed in the contralateral oculomotor nucleus. Therefore, an innervation pattern in which the medial rectus muscle is innervated by contralateral motoneurons is the primitive condition for cartilaginous fishes.     

Endothelial dysfunction in cardiovascular disease

A 34-year-old man presented with acute hemolytic anemia secondary to acute viral hepatitis A and a coexisting acute cytomegalovirus infection. This association has not been described previously in patients with glucose-6-phosphate dehydrogenase deficiency and is the subject of this report.