HIV and AIDS related knowledge,sources of information,and reported need for further education among dental students in Sudan- a cross sectional study

Background  

Information on the HIV and AIDS-related knowledge among dental students provides a crucial foundation for efforts aimed at developing an appropriate dental curriculum on HIV and AIDS, and for attracting the attention of dental school educators towards the subject.     

Flexibility of the use of residual tibial anterior motor units during walking in neuromuscular diseases

The use of tibial anterior (TA) motor units in lower motoneurone disorders was studied during comfortable walking that was the main function of TA. The findings were compared to those in normal subjects. The loss of TA power was compensated either by increases of recruitment and firing rate of residual TA units or by a change from the normal plantigrade gait pattern to the infantile digitigrade pattern putting less strain on TA. Moderately paralysed subjects usually maintained plantigrade gait by excessive use of residual TA units but tended to change to digitigrade gait on fatigue thus economizing with remaining TA power. Severely paralysed subjects used digitigrade gait but plantigrade gait could be restored by application of a toe using string, i.e. the string might increase the strain on TA instead of decreasing it.     

Principles for enhanced recruitment of subjects in a large clinical trial. the XENDOS (XENical in the prevention of Diabetes in Obese Subjects) study experience

In most clinical trials it is problematic to recruit enough patients within a reasonable time period. Prolonged or inefficient recruitment or both can have negative scientific and economic consequences. The XENDOS (XENical in the prevention of Diabetes in Obese Subjects) study is an ongoing randomized, double-blind, placebo-controlled, prospective, multicenter trial investigating whether orlistat combined with hypocaloric diet and moderate physical exercise can reduce the incidence of diabetes in obese subjects. To implement the XENDOS protocol and recruit the study patients, we designed a system for centralized patient recruitment and centralized scheduling of patients and staff at the 22 collaborating centers. The recruitment and inclusion phase was divided into a series of different consecutive examinations of increasing complexity. Relatively simple initial examinations enabling a large throughput of patients were followed by more detailed examinations of fewer subjects, by then known to fulfil some of the study-specific requirements. With the aid of object-oriented techniques, the software was modularized to enable concurrent engineering. We also selected a structure where plug-in modules handling specific tasks could be added to the system as needed. The design was supported by a flow-oriented view of the progress of the patients through the study. With this overall solution we managed to include 3305 subjects (98.8% of the requested number) within less than 4 months. The sex distribution (44.8% men) and the number of patients with impaired glucose tolerance (IGT), (21.1%) were in close accordance with, or far better than, the requirements of the protocol (45% men, at least 10% IGT patients). The basic design of the XENDOS information system can be adapted to fulfil the requirements of other study protocols within the fields of obesity, diabetes, hypertension, coronary heart disease, etc. Shortening the recruitment and inclusion phase of large clinical trials is of great value both to be medical society and the pharmaceutical industry.     

Thyrotoxic atrial fibrillation: an underdiagnosed or overdiagnosed condition?

Hyperthyroidism has been considered to be underdiagnosed as a pathogenetic factor for atrial fibrillation, according to results of thyroliberin stimulation tests. We assessed, clinically and biochemically, thyroid function in 110 ambulatory patients with atrial fibrillation [mean age 64 (SD 11) years] from a group of consecutive cases referred to a specialist cardiology unit during one year. Patients finally categorized as euthyroid (n = 100) commonly presented with one or more symptoms or signs considered to be typical for thyrotoxic patients. Three patients (2.7%; 95% confidence interval, 0-7.5%) fulfilled criteria for hyperthyroidism, but only one was identified from clinical examination. The thyroliberin stimulation test (performed in all patients) identified another seven patients who might have been classified as hyperthyroid according to commonly used criteria for an abnormal thyrotropin response. However, none of these seven patients was judged as hyperthyroid after follow-up. Their thyrotropin concentrations were all above the detection limit for the immunoenzymometric assay. With few exceptions, they had thyroid hormone concentrations within reference limits calculated from the results for the 100 euthyroid subjects, and their concentration ratio for free 3,5,3'-triiodothyronine to free thyroxin, 0.31 (SD 0.05), was lower than that found in the euthyroid group [0.38 (SD 0.08), P less than 0.05]. We conclude that (a) criteria for evaluating results of the thyroliberin stimulation test should be revised, (b) this test is still useful in evaluating suspected cases of hyperthyroidism, for which results of current, improved methods for thyrotropin determination are equivocal, and (c) improved diagnostic methods should be used to characterize the relative importance of hyperthyroidism as a causal factor for atrial fibrillation.     

Effects of fucosylated milk of goat and mouse on Helicobacter pylori binding to Lewis b antigen

AIM:To evaluate the effects of animal milk containing fucosylated antigens on Helicobacter pylori (H pylon) binding to Lewis b antigen.METHODS:A mammary gland expression vector containing human α1-3/4-fucosyltransferase cDNA sequences was constructed. Transient expression of human(α1-3/4-fucosyltransferase cDNA in goat mammary cell and establishment of transgenic mice were performed. The adhesion inhibitory properties of milk samples were analyzed by using Hpylori.RESULTS: Goat milk samples were found to inhibit bacterial binding to Lewis b antigen. The highest inhibition was observed 42 h after injection of the plasmid. The binding activity of Hpylori to Lewis b antigen reduced mostly, by 83%, however milk samples from transgenic mice did not inhibit Hpylori binding to Lewis b antigen.CONCLUSION: The use of “humanized“ animal milk produced by the transgenic introduction of fucosylated antigen can perhaps provide an alternative therapy and preventive measure for Hpylori infection.     

Health-related quality of life among children,adolescents, and adults with bladder exstrophy–epispadias complex: a systematic review of the literature and recommendations for future research

Quality of Life Research - Bladder exstrophy–epispadias complex (BEEC) is a rare spectrum of genitourinary malformations. Children risk long-term urinary and genital dysfunctions. To achieve...     

Clonal success of piliated penicillin nonsusceptible pneumococci

Antibiotic resistance in pneumococci is due to the spread of strains belonging to a limited number of clones. The Spain(9V)-3 clone of sequence type (ST)156 is one of the most successful clones with reduced susceptibility to penicillin [pneumococci nonsusceptible to penicillin (PNSP)]. In Sweden during 2000-2003, a dramatic increase in the number of PNSP isolates was observed. Molecular characterization of these isolates showed that a single clone of sequence type ST156 increased from 40% to 80% of all serotype 14, thus causing the serotype expansion. Additionally, during the same time period, we examined the clonal composition of two serotypes 9V and 19F: all 9V and 20% of 19F isolates belonged to the clonal cluster of ST156, and overall approximately 50% of all PNSP belonged to the ST156 clonal cluster. Moreover, microarray and PCR analysis showed that all ST156 isolates, irrespective of capsular type, carried the rlrA pilus islet. This islet was also found to be present in the penicillin-sensitive ST162 clone, which is believed to be the drug-susceptible ancestor of ST156. Competitive experiments between related ST156 serotype 19F strains confirmed that those containing the rlrA pilus islet were more successful in an animal model of carriage. We conclude that the pilus island is an important biological factor common to ST156 isolates and other successful PNSP clones. In Sweden, a country where the low antibiotic usage does not explain the spread of resistant strains, at least 70% of all PNSP isolates collected during year 2003 carried the pilus islet.     

Method for patient-specific finite element modeling and simulation of deep brain stimulation

Deep brain stimulation (DBS) is an established treatment for Parkinson’s disease. Success of DBS is highly dependent on electrode location and electrical parameter settings. The aim of this study was to develop a general method for setting up patient-specific 3D computer models of DBS, based on magnetic resonance images, and to demonstrate the use of such models for assessing the position of the electrode contacts and the distribution of the electric field in relation to individual patient anatomy. A software tool was developed for creating finite element DBS-models. The electric field generated by DBS was simulated in one patient and the result was visualized with isolevels and glyphs. The result was evaluated and it corresponded well with reported effects and side effects of stimulation. It was demonstrated that patient-specific finite element models and simulations of DBS can be useful for increasing the understanding of the clinical outcome of DBS.     

Multiple forms of long-term plasticity at unitary neocortical layer 5 synapses

Long-term potentiation and depression (LTP and LTD) are cellular plasticity phenomena expressed at a variety of central synapses, and are thought to contribute to learning and developmental changes in circuitry. Recurrent neocortical layer-5 synapses are thought to express a presynaptic form of LTP that influences the short-term plasticity of the synapse. Here we show that changes in synaptic strength elicited by pairing high frequency pre- and postsynaptic firing at this synapse result from a mixture of presynaptic and postsynaptic forms of plasticity, as assessed by the analysis of changes in coefficient of variation, short-term plasticity, and NMDA:AMPA current ratios. Pharmacological dissection of this plasticity revealed that block of presynaptic LTD with an endocannabinoid inhibitor enhanced LTP, while the apparently presynaptic component of LTP could be prevented by induction in the presence of blockers of nitric oxide. These data suggest that correlated high-frequency firing at layer-5 synapses simultaneously induces a mixture of presynaptic LTD, presynaptic LTP, and postsynaptic LTP.