Students performance and perception of neurophysiology: feedback for innovative curricular reform in a Nigerian medical school.

This study aimed at ascertaining the status of students' performances and their perception of the learning of neurophysiology in a Nigerian medical school. The goal of the study was to determine ways of addressing identified negative perceptions for the purpose of improving upon the overall learning and use neurophysiology knowledge by structured curricular reform. We analyzed and compared the performances of students in three areas of physiology at the second professional examinations over a three-year period [n=300]. We also surveyed learning experience of a batch of graduating doctors in neurosciences [n=50] and surveyed the staff and students' perception of the teaching of neurophysiology. The students performances in neurophysiology was comparatively poorer than in cardiovascular and endocrinology aspects of the subject over a three year period at the second professional examinations. The reported students perception of their neurophysiology learning included uninteresting, abstract concepts, lack of real examples and conflicting facts with their prior basic knowledge. Over 50% of the graduates rated their learning experiences as poor or very poor or below average for the neuroscience courses. The analyses of the curricular contents of neurophysiology in the preclinical departments indicted asynchrony and redundancy in topics that may reduce the learning and reduce teaching time efficiency of the neuroscience courses. It is suggested that learning experiences of medical students should be routinely monitored and structured to ensure that the graduate doctor is able to understand and transfer learned experiences into clinical studies and practice. A horizontally integrated curriculum may be one way of raising students knowledge, attitude and skills in neuroscience courses as taught in the preclinical departments and is suggested.

Effect of training location on students' clinical skills.

The clinical skills of second-year medical students trained in a hospital-based setting were compared with those of students trained in a community setting using an objective structured clinical exam. No statistically significant difference was found.

Model-based neural network for target detection in SAR images.

A controversial issue in the research of mathematics of intelligence has been that of the roles of a priori knowledge versus adaptive learning. After discussing mathematical difficulties of combining a priority with adaptivity encountered in the past, we introduce a concept of a model-based neural network, whose adaptive learning is based on a priori models. Applications to target detection in SAR images are discussed. We briefly overview the SAR principles, derive relatively simple physics-based models of SAR signals, and describe model-based neural networks that utilize these models. A number of real-world application examples are presented.

Intrasellar paraganglioma: report of a case in a sibship of von Hippel-Lindau disease.

Although uncommon, paragangliomas are known to affect the central nervous system. Those that arise in the sellar region are particularly rare. We report the clinicopathological features of a paraganglioma occurring in the setting of von Hippel-Lindau disease, a disorder in which paragangliomas are known to occur. We also present a review of the literature.

Probe amplifier system based on chimeric cycling oligonucleotides.

Amplification systems are required as part of DNA probe technology, since traditional non-amplified oligonucleotide hybridization using nonradioactive detection methods have detection limits of approximately 10(8) molecules. We present a probe amplifier technology suitable for use in large-scale automated clinical diagnostic systems. It is fast, sensitive and performs at a constant temperature. The system functions by allowing a single target molecule to act as a catalyst in converting a large number of probe molecules to a unique detectable form. We refer to this catalytic amplification process as the "cycling probe reaction." The basis of the system is an oligomer probe construction consisting of a DNA-RNA-DNA sequence.

Quantitation and localization of apolipoproteins [a] and B in coronary artery bypass vein grafts resected at re-operation.

Lp[a] is a lipoprotein whose plasma concentration is highly correlated with cardiovascular disease. Its protein moiety, apoLp[a], consists of two large polypeptides, apo[a] and apo B. The possible contribution of Lp[a] to atherosclerosis in saphenous vein aortocoronary bypass grafts was studied in a population of patients undergoing coronary re-bypass surgery. The vein graft tissue levels of apoLp[a] were compared with graft duration, gross and light microscopic pathology, as well as plasma levels of apoLp[a]. The localization pattern of apo[a] and apo B in vein graft tissue was determined. In addition, the plasma levels of cholesterol, triglycerides, apoproteins (apo) A-I, A-II, and E were measured. In a representative subpopulation of 17 patients with a mean age of 63 years from whom grafts with a mean duration of 112 months were resected, the mean total plasma cholesterol level was 221 mg/dl, the mean high density lipoprotein cholesterol level was 31 mg/dl, and the mean plasma triglyceride level was 228 mg/dl. In normal saphenous veins, the level of apoLp[a] was below measurable limits (less than 2 ng/mg), and the level of apo B was very low (3.3 ng/mg). In resected grafts, the mean tissue level of apoLp[a] was 32 ng/mg, and that of apo B was 70 ng/mg, demonstrating the net accumulation of these apoproteins in veins from the time of their grafting into the arterial bed. The apoLp[a]/apo B ratio was determined in 77 tissue segments from 59 grafts (28 patients) and was found to be 0.313. This tissue ratio was significantly higher (p = 0.02) than the plasma apoLp[a]/apo B ratio from these patients, which was 0.132. Immunostaining showed co-localization of apo[a] and apo B in the neointima of grafts. The most abundant pathologic features observed in resected grafts were proliferated intima (43/52), thrombus (28/52), and atherosclerotic core regions (21/52). The level of tissue apo B correlated well with the abundance of core regions (r = 0.501), whereas the level of tissue apoLp[a] did not correlate as well with this feature (r = 0.233). Although apo[a] and apo B are almost absent from normal saphenous vein, these apoproteins (and presumably the lipoproteins Lp[a] and low density lipoprotein) accumulate in bypass vein grafts. The data support the view that these lipoproteins play a significant role in vein graft atherosclerosis.

Clinical evaluation of methylcellulose as a bulk laxative.

We studied a bulk laxative containing methylcellulose in a group of normal subjects as well as in a group of chronically constipated individuals. The initial study in normal subjects was performed to show that the compound could increase fecal weight without significant side effects. Fifty healthy subjects were studied. Methylcellulose in daily doses of 4 g demonstrated a statistically significant increase in fecal frequency, fecal water, and fecal solids. In the second phase, we studied a group of 59 chronically constipated individuals treated with daily doses of the laxative containing either 1, 2, or 4 g of methylcellulose or 3.4 g psyllium. All of these doses resulted in statistically significant increases in stool frequency, water content, and fecal solids. There was no increase in individual stool weight from any of the laxative doses. Methylcellulose, in a daily dose as low as 1 g, is an effective laxative.

Polymeric thiols as enzyme activators of serum creatine phosphokinase.

Several hydrophilic polymeric thiols were prepared from amino-activated polymeric supports by reaction with N-acetylhomocystein ethiolactone. Supports include agaroses, cellulose, Glycophase controlled-pore glass, and Matrex acrylic beads. Thiol content in these polymers was 3-72 mumol SH/g dry polymer. Several were effective solid-phase activators of the sulfhydryl-dependent enzyme creatine phosphokinase at concentrations comparable to that of monomeric thiol required for enzyme activation. The kinetic activation curves for the polymeric and the monomeric (thioglucose) activators were similar, suggesting unhindered interaction of the enzyme with the polymeric activator.

Maturational changes in the pharmacological characteristics and actomyosin content of canine arterial and venous tissue.

The purpose of this study was to compare the pharmacological characteristics and actomyosin content of arterial and venous tissue at different times during development. Rings of arteries (femoral, renal, carotid, pulmonary) and veins (saphenous, pulmonary, jugular) were obtained from 1 wk, 1 month, and adult dogs, mounted at their optimal length for force development and the contractile response to potassium chloride and phenylephrine determined. The strain at optimal length was less at all ages in pulmonary artery and pulmonary and jugular veins than in other vessels. All vessels exhibited an increase in maximum contractile response with development but the increase was greater for phenylephrine. In general, the magnitude of the maximum response of the jugular and pulmonary veins and pulmonary artery was less than other vessels at all ages. The sensitivity (half maximum response) either increased or was unchanged in arteries with development, while in the veins it either decreased or was unchanged. The relaxant effects of verapamil and isoproterenol were determined on potassium chloride contracted vessels. Arterial tissue was minimally responsive to isoproterenol at all ages while venous tissue either increased its responsiveness (saphenous, pulmonary) with development or remained highly responsive (jugular). Verapamil, unlike isoproterenol, was an effective relaxant of all vessels. The actomyosin content (mg/mm) of femoral and renal arteries and saphenous and jugular veins increased with development but this increase was accompanied by a parallel increase in total protein so that the ratio (actomyosin/total protein) was unchanged. In jugular veins from adult dogs this ratio was smaller than in arterial tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

A multilayer element for determining hemoglobin in whole blood: principles and analytical performance.

We described the structure and analytical performance of a thin-film element for determining total hemoglobin in whole blood. The element can be used with the Kodak Ektachem DT60 analyzer. The method, analogous to the standard Drabkin's method, provides accurate and precise results on 10-microL samples of undiluted whole blood. Dynamic range is linear from 0 to 200 g/L, and the method is relatively free from interference.

The relationship between color preference and psychiatric disorders.

The relationship between color preference and psychiatric disorders was studied in an outpatient psychiatric sample (N = 1,143). The results were studied by gender and by age. The patients' choice of Luscher's eight colors revealed a sex difference, but only minor variations with age. The present data show both consistencies and discrepancies with past data.

An unusual fibro-osseous lesion of the brain. Case report.

An unusual case is described of a fibro-osseous lesion of the brain. Some other causes of densely calcified intracranial lesions are briefly discussed.

Recognition of suicide signs by physicians in different areas of specialization.

Although physicians play a major role in dealing with potentially suicidal individuals, little research has been conducted to assess physicians' knowledge of who may or may not present a suicidal risk. The authors in this article present data on the ability of 202 physicians to recognize well established signs of suicide potential. Physicians in 14 areas of medical specialization completed a 13-item, multiple-choice examination of components taken from a suicide potential rating scale. The results revealed that certain groups of physicians predictably scored highest (for example, psychiatrists) but that most physicians were equally knowledgeable about the signs studied.