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PubMed1999

Lumbosacral instrumented fusion: analysis of 124 consecutive cases.

One hundred twenty-four cases of lumbosacral fusion receiving transpedicular screw fixation were divided into two groups and reviewed retrospectively. The conditions treated include spondylolisthesis, scoliosis, tumor, trauma, and degenerative disc disease. There were 83 males and 41 females in this consecutive series averaging a 45.2-month follow-up. The primary or first-time arthrodesis rate was 91.9%. A learning curve effect as it relates to operative time but not pedicular screw placement was shown. Instrumentation-related and general medical and surgical complications were low. Infection rates were also low; superficial 2.4%, deep 1.6%. Nonunion or delayed union was salvaged in 10 cases, improving the overall fusion rate to 97.6%. The results of this study support the use of lumbosacral transpedicular screw fixation in select spinal conditions.

Adolescent↗
PubMed2004

Basic medical science education must include medical informatics.

Medical Informatics is the science and art of processing medical information. In this age of "Information Explosion" choosing the useful one is rather difficult, and there lies the scope of electronic database management. However, still many outstanding personnel related to the healthcare sector take pride in being "computer illiterate". The onus of the best use lies on the end-user health care providers only. Another term tele-health encompasses all the e-health and telemedicine services. Computer aided or assisted learning (CAL) is a computer based tutorial method that uses the computer to pose questions, provide remedial information and chart a student through a course. Now the emphasis in medical education, is on problem based learning (PBL) and there CAL could be of utmost help if used judiciously. Basic Medical Education and Research lays the foundation for advancing and applying proper healthcare delivery systems. There is no doubt that deep knowledge of anatomy is mandatory for successful surgery. Also, comprehensive knowledge of physiology is essential for grasping the principles of pathology and pharmacology adequately, to avoid incorrect and inadequate practice of medicine. Similarly, medical informatics is not just a subject to be learnt and forgotten after the first professional MBBS examination. The final aim of every student should not only be to become a good user but also an expert for advancing medical knowledge base through medical informatics. In view of the fast changing world of medical informatics, it is of utmost necessity to formulate a flexible syllabus rather than a rigid one.

Education, Medical↗
PubMed2004

Vision in the dimmest habitats on earth.

A very large proportion of the world's animal species are active in dim light, either under the cover of night or in the depths of the sea. The worlds they see can be dim and extended, with light reaching the eyes from all directions at once, or they can be composed of bright point sources, like the multitudes of stars seen in a clear night sky or the rare sparks of bioluminescence that are visible in the deep sea. The eye designs of nocturnal and deep-sea animals have evolved in response to these two very different types of habitats, being optimised for maximum sensitivity to extended scenes, or to point sources, or to both. After describing the many visual adaptations that have evolved across the animal kingdom for maximising sensitivity to extended and point-source scenes, I then use case studies from the recent literature to show how these adaptations have endowed nocturnal animals with excellent vision. Nocturnal animals can see colour and negotiate dimly illuminated obstacles during flight. They can also navigate using learned terrestrial landmarks, the constellations of stars or the dim pattern of polarised light formed around the moon. The conclusion from these studies is clear: nocturnal habitats are just as rich in visual details as diurnal habitats are, and nocturnal animals have evolved visual systems capable of exploiting them. The same is certainly true of deep-sea animals, as future research will no doubt reveal.

Animals↗
PubMed2005

Ultrasound in rheumatology.

Over the last decade, several studies have highlighted the value of ultrasonography for both clinical and research purposes in rheumatology. Ultrasonography is a non-invasive, inexpensive and free-of-radiation-hazards imaging technique providing quick and useful information for the management of rheumatic diseases. Considerable evidence supporting the role of ultrasonography in rheumatological clinical practice has led many rheumatologists to want to become experienced with this imaging technique. The main indications of ultrasonography in rheumatology include the evaluation of patients with regional pain syndromes and chronic arthritis, short-term therapy monitoring and guidance for invasive procedures. Ultrasonography's long learning curve is the main obstacle that hinders its widespread use in rheumatology. Many technical aspects may affect the scanning process and a correct interpretation of sonographic images depends on several elements such as a deep knowledge of ultrasonography anatomy and pathology.

Clinical Trials as Topic↗
PubMed2004

Deep venous thrombosis.

Venous thromboembolism (VTE), manifested as either deep venous thrombosis (DVT) or pulmonary embolism (PE), is an extremely common medical problem, occurring either in isolation or as a complication of other diseases or procedures. Yet, despite its frequency, much remains to be learned regarding the pathogenic mechanisms that initiate VTE, about tailoring its treatment to the individual with her/his specific set of risk factors for recurrence, and about its medical management when associated with specific disease entities, such as cancer. These three topics are addressed in this chapter. In Section I, Drs. López and Conde discuss the mechanisms by which venous thrombi may be initiated on the vessel wall in the absence of anatomically overt vessel wall injury. The authors propose a model whereby tissue factor (TF)-bearing microvesicles that arise from cells of monocyte/macrophage lineage can fuse with activated endothelial cells in regions of vessel activation or inflammation and initiate blood coagulation. Key components of this model include docking of the microvesicles to the stimulated endothelium through P-selectin glycoprotein ligand-1 on their surfaces binding to either P-selectin or E-selectin on the endothelium, and the role of hypoxia during blood stasis in initiating local endothelial activation. Elevations in the levels of TF-bearing microvesicles associated with inflammatory conditions would help to explain the increased risk of thrombosis associated with infections and inflammatory states such as inflammatory bowel disease. In Section II, Dr. Clive Kearon discusses the risk factors for recurrent thrombosis and strategies for determining length of therapy and tailoring specific therapies through risk stratification. Those patients who experience VTE in association with a major reversible risk factor such as surgery are much less likely to experience a recurrence when anticoagulation is discontinued than are patients with a persistent risk factor, such as thrombophilia or cancer unresponsive to therapy. Those with a minor reversible risk factor, such as prolonged air travel, have an intermediate risk of recurrence after discontinuance of anticoagulant therapy. The author provides an algorithm for using risk assessment as a means of determining the length and type of therapy to be used to minimize the rate of recurrence while simultaneously diminishing the risk of bleeding associated with anticoagulation. In Section III, Dr. Agnes Lee updates the topic of VTE associated with malignancy. Patients with cancer make up approximately 20% of those presenting with first time VTE, and the presence of VTE forebodes a much poorer prognosis for patients with cancer, likely because of the morbidity associated with VTE itself and because VTE may herald a more aggressive cancer. Recent evidence indicates that low-molecular weight heparins (LMWHs) improve survival in patients with advanced cancer through mechanisms beyond their effect as anticoagulants. Because of their improved efficacy and safety and potential anti-neoplastic effect, the LMWHs have become the anticoagulants of choice for treating VTE associated with cancer.

Heparin, Low-Molecular-Weight↗
PubMed2005

The evolution of music in comparative perspective.

In this paper, I briefly review some comparative data that provide an empirical basis for research on the evolution of music making in humans. First, a brief comparison of music and language leads to discussion of design features of music, suggesting a deep connection between the biology of music and language. I then selectively review data on animal "music." Examining sound production in animals, we find examples of repeated convergent evolution or analogy (the evolution of vocal learning of complex songs in birds, whales, and seals). A fascinating but overlooked potential homology to instrumental music is provided by manual percussion in African apes. Such comparative behavioral data, combined with neuroscientific and developmental data, provide an important starting point for any hypothesis about how or why human music evolved. Regarding these functional and phylogenetic questions, I discuss some previously proposed functions of music, including Pinker's "cheesecake" hypothesis; Darwin's and others' sexual selection model; Dunbar's group "grooming" hypothesis; and Trehub's caregiving model. I conclude that only the last hypothesis receives strong support from currently available data. I end with a brief synopsis of Darwin's model of a songlike musical "protolanguage," concluding that Darwin's model is consistent with much of the available evidence concerning the evolution of both music and language. There is a rich future for empirical investigations of the evolution of music, both in investigations of individual differences among humans, and in interspecific investigations of musical abilities in other animals, especially those of our ape cousins, about which we know little.

Animals↗
PubMed2001

[A case of late-onset carbamoyl phosphate synthetase I deficiency, presenting periodic psychotic episodes coinciding with menstrual periods].

Carbamoyl phosphate synthetase I deficiency (CPSID) is a rare metabolic disorder affecting the first enzymatic step of urea cycle. We report clinical manifestations of a female case of late-onset CPSID in Japan. An 18-year-old girl was admitted to emergency room due to acute comatose state. Her parents had no apparent consanguineous history. She had suffered from intermittent psychotic episodes (excitation, aggressive behavior and insomnia) with nausea and vomiting from the age of 13, mostly coinciding with menstrual period. She had minor learning disability without major neurological deficits and convulsions. Her mental status was estimated as normal in her intermenstrual period. She had been diagnosed as having hysteria and premenstrual syndrome. Her neurological findings on admission showed deep coma and hypotonic tetraparesis. Plasma ammonia level was markedly elevated (684 micrograms/dl) without significant liver dysfunction. Blood urea nitrogen decreased to 6 mg/dl. Continuous venovenous filtration with subsequential administration of sodium benzoate and l-arginine was started to eliminate blood ammonia. Although the plasma ammonia level decreased to 300 mu/dl in next 10 hours, severe cerebral edema was observed in head computed tomography subsequently, followed by marked cerebral atrophy. Finally, her consciousness status became almost alert a month after the onset, but her mental status was severely retarded. CPSI activity of her biopsied liver markedly decreased and she was diagnosed as having CPS ID. CPSI cDNA analysis of her biopsied liver demonstrated a V1149G mutation. Genomic DNA analysis showed that she was heterozygous in V1149G mutation. The mutation allele was derived from her father. The causative factor for absence or very low level of maternal CPSI mRNA will require further analysis.

Adolescent↗
PubMed2004

Is bed rest an effective treatment modality for pressure ulcers?

Despite the well-documented medical, physical, and psychological complications associated with this care management option, bed rest remains a frequently prescribed treatment modality for conditions such as pressure ulcers. Cognitive and psychosocial complications of bed rest include depression, learned helplessness, perceptual changes, and fatigue. Physically, complications can include contractures, muscle atrophy, osteoporosis, pathologic fractures, urinary tract infections, decreased cardiac reserve, decreased stroke volume, resting and post-exercise tachycardia, orthostatic hypotension, pulmonary embolism, deep venous thrombosis, pneumonia, anorexia, constipation, and bowel impaction. Furthermore, the literature does not contain evidence supporting the use of bed rest to facilitate healing of pressure ulcers. More suitable approaches to pressure ulcer care include limiting bed rest, initiating occupational therapy, integrating meaningful tasks into daily activities, increasing outside stimulation, involving patients in care decisions and addressing their concerns, optimizing nutritional status, and managing pressure and shear throughout daily activities. Recommendations for implementing alternatives to bed rest are addressed.

Activities of Daily Living↗
PubMedDate not supplied

[The characteristics of exploratory behavior in Wistar rats in a permanent inhomogeneous magnetic field].

The influence of weak perturbations (up to 300 microT) in the natural magnetic field (MF) (induced by the introduction of three constant magnets) on the problem task solving in complex maze was studied in two groups of Wistar rats. Under the action of inhomogeneous magnetic field there were no spontaneous change of the orienting for the explorative activity independently of the individual in the presence of the organization of goal-directed behaviour. Instead of the expected explorative activity, the stable and deep locomotor depression developed after orienting in a new environment. Such a phenomenon was manifested only against the background of informational loading. Nevertheless, under these conditions a short external stimulations resulted in even faster rat learning than in the control animals. It is suggested that the MF characteristics play a crucial role in the transformation of the orienting (unconditioned activity) into the explorative (cognitive) activity.

Animals↗
PubMed1997

Dementia associated with periventricular and deep white matter alterations: a subtype of subcortical dementia.

This research examined the neuropsychological functioning of demented patients with periventricular and deep white matter alterations. Thirty-three outpatients with NINCDS-ADRDA probable Alzheimer's disease (AD) and 27 outpatients with probable/ possible ischaemic vascular dementia (IVD, Chui et al., 1992) associated with periventricular and deep white matter alterations matched for age, education, level of dementia, and functional disability were studied. White matter alterations were measured using a 40-point scale previously described by Junque et al. (1990). Subjects with cortical CVAs were excluded. On executive control tests, IVD subjects made more preservations on tests of mental control and response set, and produced fewer responses on phonemic controlled oral word association tests (letters: F,A,S). IVD subjects also made more preservations and graphomotor errors on clock drawings. On the California Verbal Learning Test the IVD group performed better than AD subjects on the short delay free recall test condition, the recognition discriminability index, and made fewer intrusion errors on both free and cued recall conditions. We conclude that neuropsychological assessment can differentiate AD from IVD associated with white matter alterations, and that the neuropsychological profile of demented subjects with significant periventricular and deep white matter alterations is similar to other subcortical dementing illnesses.

Journal Article↗
PubMed1996

The effects of shopping cart design and prior behavioral history on children's standing in cart seats.

Twenty one males 17-22 months old took part in an experiment of the effects of shopping cart design on standing in the seat section of the cart and speed of standing. Two different cart designs were examined. It was predicted that standing would be more likely in the over-the-counter vs deep basket type of cart since the former is less confining because of a larger seating area and larger leg holes. In fact, standing was slightly more likely to occur in the deep basket cart. The strongest predictors of standing, however, were subjects' prior incidents of standing in the cart seat and climbing out of the cart seat in grocery store settings. Thus, inter-individual differences in learning history may determine a child's risk of injury around shopping carts more than features of the cart's design.

Accident Proneness↗
PubMed1983

Two-way avoidance and acute shock stress induced alterations of regional noradrenergic, dopaminergic and serotonergic activity in Roman high- and low-avoidance rats.

Various brain regions of male RHA/Verh and RLA/Verh rats were dissected out and deep-frozen immediately after 30 min in a shuttle box involving a) no shock (control), b) 40 inescapable shocks or c) 40 avoidable shocks. The RHA/Verh rats used in the "c" category exhibited about 80-85% learned avoidance. 5-HT, 5-HIAA, NA, MHPG-SO4, DA, DOPAC and HVA levels were subsequently measured in selected regions. NA levels were considerably reduced in the hypothalamus and pons/medulla of both selected lines of rats after acute shock stress, supporting the results of numerous studies which have indicated that NA turnover is nonspecifically increased by all types of stress, at least in those regions. An increase in cortical MHPG-SO4 and a reduction in hypothalamic 5-HT seen after avoidance learning also occurred after shock stress in RHA/Verh rats. Whereas RLA/Verh rats showed an increased metabolism of 5-HT in the hypothalamus and pons/medulla after shock stress, RHA/Verh rats showed the opposite response in the hypothalamus after the same treatment. A reduction in 5-HT metabolism was also evident in RHA/Verh rats, after avoidance learning, in the cortex, hippocampus and hypothalamus. These results indicated, pending further studies regarding, for example, possible genetic differences in tryptophan uptake and utilization, that 5-HT probably plays at least a modulatory role in the reaction to stress, and in avoidance behavior. That role may be either active or passive, depending upon the emotional status of the subjects. In regard to the DA responses measured in striatum and hypothalamus of the two rat lines, some divergent inter-treatment tendencies, as well as some similarities, were seen in DA metabolism in both regions, but almost none of the differences were significant.

Animals↗
PubMed1988

Acquisition of a complex place task in rats with selective ibotenate lesions of hippocampal formation: combined lesions of subiculum and entorhinal cortex versus hippocampus.

The effects of isolating the hippocampus from its neocortical inputs and outputs by damaging the deep layers of entorhinal cortex and subiculum were compared with direct removal of the hippocampus using acquisition of a complex radial maze task. A series of eight problems (four out of eight arms being correct) were learned under either massed (45 s) or distributed (10 min) practice conditions, thus varying contextual information. Performance of rats with subiculum/entorhinal cortex lesions was similar to that of controls in all aspects of the radial maze task; whereas animals with hippocampal lesions were impaired on nearly all dependent measures. Although the effects of varying the intertrial interval were generally small, distributed practice did serve to facilitate the performance of hippocampal rats in terms of working memory. These findings are discussed as they related to recent theorizing in the area.

Animals↗
PubMed1998

Inhibitory long-term potentiation underlies auditory conditioning of goldfish escape behaviour.

Long-term potentiation (LTP), the increase in synaptic strength evoked by high-frequency stimulation, is often considered to be a cellular model for learning and memory. The validity of this model depends on the assumptions that physiological stimuli can induce LTP in vivo and that the resulting synaptic modifications correlate with behavioural changes. However, modifiable synapses are generally embedded deep in complex circuits. In contrast, the goldfish Mauthner (M)-cell and its afferent synapses are easily accessible for electrophysiological studies, and firing of this neuron is sufficient to trigger fast escape behaviour in response to sudden stimuli. We have previously shown that tetanic stimulation can induce LTP of the feedforward inhibitory synapses that control the excitability of the M-cell. Here we report that natural sensory stimulation can induce potentiation of this inhibitory connection that resembles the LTP induced by afferent tetanization. Furthermore, comparable acoustic stimulation produced a parallel decrease in the probability of the sound-evoked escape reflex. Thus we demonstrate for the first time, to our knowledge, a behavioural role for the long-term synaptic strengthening of inhibitory synapses.

Acoustic Stimulation↗
PubMed2000

Asymmetry between encoding and retrieval processes: evidence from divided attention and a calibration analysis.

Two experiments provide further information on the effects of divided attention (DA) on encoding and retrieval processes. The first experiment examined the effects of decision and motor difficulty of a concurrent reaction time task. A calibration analysis was used in the second experiment to test the hypothesis that shifting attentional emphasis away from encoding to the secondary task reduces the level of processing the to-be-remembered items receive. Overall, the results confirm and extend the conclusions of Craik, Govoni, Naveh-Benjamin, and Anderson (1996) and Naveh-Benjamin, Craik, Guez, and Dori (1998), by pointing to clear differences between encoding and retrieval processes: Encoding is affected by simultaneous task demands, especially those associated with "central" resources involved in conscious decision making, whereas retrieval is obligatory in that it is largely immune to the effects of simultaneous demands. The results of the calibration analysis suggest that one reason for the poorer memory performance as a result of DA at encoding is a qualitative shift to less deep, elaborative strategies.

Attention↗
PubMed2006

Migration patterns following HIV diagnosis among adults residing in the nonurban Deep South.

Health care needs of those infected with the human immunodeficiency virus (HIV) and subsequent transmission dynamics are altered by migration after infection. We interviewed 760 HIV-infected persons attending HIV-specialty clinics living in non-urban Alabama and Mississippi to ascertain the likely geographic origins of their infections, determine their post-HIV diagnosis mobility, and identify predictors of this mobility. Most subjects (81%) were living in these two states when diagnosed and have not moved since learning of their HIV status (70%). Of those who moved their primary residence post-HIV diagnosis (25% of the entire study population), the majority in-migrated to Alabama or Mississippi from elsewhere. Persons who had moved post-HIV diagnosis were more likely to be male, an injection drug user, an urban resident at HIV diagnosis, have an AIDS-defining condition, and have moved prior to HIV diagnosis. We conclude that most HIV transmission in non-urban Alabama and Mississippi is acquired locally. These results underline the need to expand HIV prevention programs in the Deep South.

Adolescent↗
PubMed2006

[Anatomy by ultrasound of the veins in the leg: essentials].

Studying the anatomy of lower extremity veins is a tedious and complex task. Although huge efforts have been undertaken to create harmonization, any global description of the venous network is encumbered by the large number of superficial and deep veins, anastomoses and collaterals, and not least by a vastly broad nomenclature. Innumerable anatomic variants contribute to creating a complicated picture. What is needed is a description that correspondingly reflects the reality. Yet, does our description reproduce the actual anatomic and pathologic circumstances? As a rule, a phlebography is performed to localize an acute or chronic venous condition. The examiner must have learn about the "healthy" to What the stethoscope is to a cardiologist, the Doppler sonography transducer was to the phlebologist, an indispensable tool. Nowadays, duplex sonography has to be called the gold standard in that it supplies the most comprehensive information for diagnosing functional disorders of the venous system, thereby enabling a clear therapeutic strategy to be delineated. Most qualitatively average or high-grade ultrasound machines are equipped with duplex sonography, which today's specialists can employ to highly efficiently render a differential diagnosis of deep vein thrombosis. Given the ethic and forensic background and the potentially lethal outcome of a misdiagnosis, the use of this diagnostic tool must be exclusively reserved for physicians with a particularly high level of skill and training. The specialist societies for ultrasonography, angiology and phlebology have published strict guidelines for teaching Doppler sonography in Switzerland.

Collateral Circulation↗