The functional role of the motor area of the cortex in the formation of riddance reactions in dogs

A model of instrumental conditioning similar to the classical model (Pavlovian) is proposed. Flexion of the ipsilateral forelimb was elicited while EDS was applied to the hind limb by stimulation of the motor area of the cortex (M1); both stimuli ceased during the raising of the forelimb. Uniform combinations of this kind led to the development of forepaw flexion reactions in response to the EDS of the hind paw. Prolongation of EDS by 3 sec following cortical stimulation led to rapid extinction of the developed reactions. Thus, the possibility of the effective instrumentalization of movements induced by stimulation of the M1 is proven. This argues that the forming "instrumental" connection (drive-motor structures) is addressed directly to the M1.     

Bithalamic hyperintensity on T2-weighted MR: vascular causes and evaluation with MR angiography

PURPOSE: To determine whether MR angiography can be used to differentiate between the two vascular causes of bithalamic hyperintensity on T2-weighted MR images: "top of the basilar" artery occlusion and deep cerebral vein thrombosis. METHODS: A retrospective review identified six patients with bithalamic T2 hyperintensity of vascular causes. MR angiography was performed in four patients, MR angiography and conventional angiography in one patient, and conventional angiography in one patient. Data pertaining to clinical presentation and hospital course were collected. MR angiographic techniques were multislab overlapping three-dimensional time-of-flight, 2-D time-of-flight, and 2-D phase-contrast. RESULTS: Three cases of top of the basilar artery occlusion and three cases of deep cerebral vein thrombosis were recognized. In all cases, T2 hyperintensity in a vascular distribution suggested cerebral occlusive disease. Infarction involving the thalami and basal ganglia was present in two cases of deep cerebral vein thrombosis. Infarction of the thalami, mesodiencephalic region, and cerebellar hemispheres was present in two cases of basilar artery occlusion. Bithalamic infarction alone was seen in one case of deep cerebral vein thrombosis and one case of basilar artery occlusion. In the five cases in which MR angiography was used, this technique accurately distinguished the vessels involved (arterial or venous). CONCLUSION: MR angiography is a useful adjunct to MR imaging in the evaluation of bithalamic T2 hyperintensity. It does help distinguish between the two vascular causes: top of basilar artery occlusion and deep cerebral vein thrombosis.     

Coiled bodies contain U7 small nuclear RNA and associate with specific DNA sequences in interphase human cells

Coiled bodies (CBs) are nuclear organelles whose structures appear to be highly conserved in evolution. In rapidly cycling cells, they are typically located in the nucleoplasm but are often found in contact with the nucleolus. The CBs in human cells contain a unique protein, called p80-coilin. Studies on amphibian oocyte nuclei have revealed a protein within the "sphere" organelle that shares significant structural similarity to p80-coilin. Spheres and CBs are also highly enriched in small nuclear ribonucleoproteins and other RNA-processing components. We present evidence that, like spheres, CBs contain U7 small nuclear RNA (snRNA) and associate with specific chromosomal loci. Using biotinylated 2'-O-methyl oligonucleotides complementary to the 5' end of U7 snRNA and fluorescence in situ hybridization, we show that U7 is distributed throughout the nucleoplasm, excluding nucleoli, and is concentrated in CBs. Interestingly, we found that CBs often associate with subsets of the histone, U1, and U2 snRNA gene loci in interphase HeLa-ATCC and HEp-2 monolayer cells. However, in a strain of suspension-grown HeLa cells, called HeLa-JS1000, we found a much lower rate of association between CBs and snRNA genes. Possible roles for CBs in the metabolism of these various histone and snRNAs are discussed.     

Body thiamine level in acute alcohol psychoses

PURPOSE: To compare admission data and academic performances of medical students younger and older than 25, and to qualify older students' experiences and perceptions in medical school. METHOD: The authors reviewed 1988-1991 data for applications to the McGill University Faculty of Medicine. Data included GPAs and MCAT scores, as well as ratings for reference letters, autobiographical statements, and interviews. For those same years, the authors measured students' academic performances in the preclinical and clinical years. The authors compared the data by students' age: "younger" students, aged 17 to 24; and "older" students, aged 25 and above. All enrolled students took the Derogatis Stress Profile, and the older students participated in focus groups. RESULTS: The older applicants had lower GPAs and MCAT scores, but higher interview and reference letter ratings. For older accepted students, basic science course scores were lower than those of younger students, but clinical scores did not differ significantly between the groups. The two groups had similar stress levels, although older students tested lower in driven behavior, relaxation potential, attitude posture, and hostility. In focus groups, the older students spoke of learning style differences, loss of social support, and loss of professional identity. CONCLUSION: Different scores in admission criteria suggest that McGill uses different standards to select older medical students. Older students admitted under different criteria, however, do just as well as do younger students by their clinical years. A broad-based study of admission criteria and outcomes for the older student population is warranted.     

Primary structure of gene H of cattle plague virus strain K]

The paper analyzes the standard legal and methodological assurance of the quality and safety of animal food raw materials and foodstuffs (meat, meat products, fish, shellfish, crayfish and their processing products) by the parasitic purity rates according the requirements under the Russian Federation's laws "On Sanitary and Epidemiological Well-Being of the Population", "On Protection of Consumer's Rights", "On Certification of Products and Services", those of SanPiN, such as 2.3.2.560-96 "Sanitary Requirements for the Quality and Safety of Food Raw Materials and Foodstuffs" and 3.2.569-96 "Prevention of Parasitic Diseases in the Russian Federation".     

Effect of reduced dietary sodium on blood pressure: a meta-analysis of randomized controlled trials

OBJECTIVE:- To ascertain whether restriction of dietary sodium lowers blood pressure in hypertensive and normotensive individuals. DATA SOURCES:- An English-language computerized literature search, restricted to human studies with Medical Subject Heading terms, "hypertension," "blood pressure," "vascular resistance," "sodium and dietary," "diet and sodium restricted," "sodium chloride," "clinical trial," "randomized controlled trial," and "prospective studies," was conducted. Bibliographies of review articles and personal files were also searched. TRIAL SELECTION:- Trials that had randomized allocation to control and dietary sodium intervention groups, monitored by timed sodium excretion, with outcome measures of both systolic and diastolic blood pressure were selected by blinded review of the methods section. DATA EXTRACTION:- Two observers extracted data independently, using purpose-designed forms, and discrepancies were resolved by discussion. DATA SYNTHESIS:- The 56 trials that met our inclusion criteria showed significant heterogeneity. Publication bias was also evident. The mean reduction (95% confidence interval) in daily urinary sodium excretion, a proxy measure of dietary sodium intake, was 95 mmol/d (71-119 mmol/d) in 28 trials with 1131 hypertensive subjects and 125 mmol/d (95-156 mmol/d) in 28 trials with 2374 normotensive subjects. After adjustment for measurement error of urinary sodium excretion, the decrease in blood pressure for a 100-mmol/d reduction in daily sodium excretion was 3.7 mm Hg (2.35-5.05 mm Hg) for systolic (P<.001) and 0.9 mm Hg (-0.13 to 1.85 mm Hg) for diastolic (P=.09) in the hypertensive trials, and 1.0 mm Hg (0.51-1.56 mm Hg) for systolic (P<.001) and 0.1 mm Hg (-0.32 to 0.51 mm Hg) for diastolic (P=.64) in the normotensive trials. Decreases in blood pressure were larger in trials of older hypertensive individuals and small and nonsignificant in trials of normotensive individuals whose meals were prepared and who lived outside the institutional setting. CONCLUSION:- Dietary sodium restriction for older hypertensive individuals might be considered, but the evidence in the normotensive population does not support current recommendations for universal dietary sodium restriction.     

An auto-scoring mechanism for evaluating problem-solving ability in a web-based learning environment

The rapid development of computer and network technologies has attracted researchers to investigate strategies for and the effects of applying information technologies in learning activities; simultaneously, learning environments have been developed to record the learning portfolios of students seeking web information for problem-solving. Although previous research has demonstrated the benefits of applying information technologies to learning activities, the difficulties in doing so have also been revealed. One of the major difficulties is the lack of a mechanism to assist teachers in evaluating the problem-solving ability of the students, such that constructive suggestions can be given to the students, and tutoring strategies can be improved accordingly.     

Software component certification

Although the stringent requirements of some critical applications may require independent certification, the authors see software developer self-certification as a viable alternative in many other cases. They accept that using software certification laboratories (SCLs) may work well for certain software distribution models, but they cannot be applied to all types of software development. The approach has several drawbacks. For example, an SCL may work well for larger software houses that ship mass-marketed software applications to the public, but it is less satisfactory for smaller developers who make reusable components or safety-critical software or for developers who belong to the freeware community