1,033 research outputs found

    Effect of hemodialysis on the hearing function of patients with chronic renal failure

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    Sensorineural hearing impairment (SHI) has been reported in chronic renal failure (CRF) patients with a prevalence of 20-40%. The aetiopathogenetic mechanisms reported included osmotic alteration resulting in loss of hair cells and in some, complications of haemodialysis have been hypothesized. We have in the past reported 2 cases of CRF patients who developed acute SHL following hemodialysis. This is a report of investigation of the effect of hemodialysis on the hearing function of CRF patients using pure tone audiometry findings. Thirty-three CRF patients were recruited for Pure Tone Audiometry (PTA) at admission and after three sessions of hemodialysis. The pure tone audiometry was done with a computer audiometer BA 20 Kamplex in the sound - proof (acoustic) booth in the ENT clinic. The duration of illness, dosage of diuretics and blood pressure were also noted. Similar age and sex-matched control were selected among volunteers who were otherwise clinically healthy. The data was processed using the Statistical Package for the Social Sciences (SPSS Inc, Chicago, Illinois, USA). Thirty-three CRF patients treated with haemodialysis and 28 healthy controls completed the study, 34 males and 27 females, age range was 16 - 72 years, mean of 45.30 (SD16.20) for subjects and 49.7 for controls. Hearing loss was found in 22/34 (67%) at recruitment and 27/34 (79%) after 3 sessions of hemodialysis. There was a significant difference between the mean pre- and post-hemodialysis PTA values, P =0.0008. There was also a significant correlation between post - hemodialysis hearing threshold and (i) duration of illness (P = 0.00340) and (ii) creatinine levels of the patients (P=0.035). In conclusion, there was a significant depression in the hearing threshold of patients with CRF following three sessions of hemodialysis. This could be caused by changes induced by hemodialysis or effects of the duration and severity of disease. African Journal of Health Sciences Vol. 13 (3-4) 2006: pp. 29-3

    Is the Art of Renal Biopsy on the Decline in Nigeria?

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    Background: Renal biopsy remains the means by which definitive parenchymal kidney disease diagnoses are made. With the renal biopsy, the activity, progression and prognosis of renal parenchymal diseases can be studied with objectivity. We investigated the trend of renal histopathology request in a tertiary hospital in Nigeria over 31 years.Objective: To determine the trend of renal biopsy requests in one of the biggest tertiary hospitals in Nigeria over a 31-year period (1981- 2011).Methods: We retrospectively analysed all the renal biopsies submitted to the Department of Pathology, University College Hospital (UCH) Ibadan, South-West Nigeria over a 30 year period (1981-2011). Trend of requests of all the biopsies submitted from the Surgery, Paediatrics and Medicine departments was analysed using a test for linear  trend. Gender and age groups trends were also studied.Results: A significant reduction in the rates of renal biopsy request over the 31-year period (p=0.001) was noted which is attributed to diminution in requests from the Medicine and Paediatrics Departments (p<0.001), while the rates of requests from Surgery Department remain fairly uniform over this period (p=0.05). Decrease in biopsy requests significantly cuts across the ages in both genders. Conclusion: Lack of adequately trained manpower, poor health insurance scheme and lack of facilities may be contributory in renal biopsy requests decline. Adequate efforts should be made towards reviving this important investigative modality in Nigerian tertiary hospitals.Keywords: Kidney, Biopsy, Histology, Trend test, UCH Ibadan

    Chemical constituents and antioxidant activity of Alstonia boonei

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    The chemical composition and some antioxidant indices of Alstonia boonei stem-bark extract were evaluated. A. boonei was found to contain important minerals like calcium, phosphorus, iron, sodium, potassium, and magnesium. Alkaloids, tannins, saponins, flavonoids and cardiac glycosides were among the phytochemicals detected together with the important vitamin, ascorbic acid. DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, total phenolic content and reducing power were41.58 Âą 1.43 %, 2.09 Âą 0.04 mg/g gallic acid equivalent and 0.32 Âą 0.01 respectively. Against the backdrop of the many medicinal uses of the plant, the results of the present work indicate that phytochemicals, other than phenolics, the mineral elements and vitamin C may be the critical factors in the medicinal effects of A. boonei

    Stochastic Gravity: Theory and Applications

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    Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel.In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime: we compute the two-point correlation functions for the linearized Einstein tensor and for the metric perturbations. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a quasi-static black hole.Comment: 75 pages, no figures, submitted to Living Reviews in Relativit

    Nonlinear Sigma Model for Disordered Media: Replica Trick for Non-Perturbative Results and Interactions

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    In these lectures, given at the NATO ASI at Windsor (2001), applications of the replicas nonlinear sigma model to disordered systems are reviewed. A particular attention is given to two sets of issues. First, obtaining non-perturbative results in the replica limit is discussed, using as examples (i) an oscillatory behaviour of the two-level correlation function and (ii) long-tail asymptotes of different mesoscopic distributions. Second, a new variant of the sigma model for interacting electrons in disordered normal and superconducting systems is presented, with demonstrating how to reduce it, under certain controlled approximations, to known ``phase-only'' actions, including that of the ``dirty bosons'' model.Comment: 25 pages, Proceedings of the NATO ASI "Field Theory of Strongly Correlated Fermions and Bosons in Low - Dimensional Disordered Systems", Windsor, August, 2001; to be published by Kluwe

    De Sitter ground state of scalar-tensor gravity and its primordial perturbation

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    Scalar-tensor gravity is one of the most competitive gravity theory to Einstein's relativity. We reconstruct the exact de Sitter solution in scalar-tensor gravity, in which the non-minimal coupling scalar is rolling along the potential. This solution may have some relation to the early inflation and present acceleration of the universe. We investigated its primordial quantum perturbation around the adiabatic vacuum. We put forward for the first time that exact de Sitter generates non-exactly scale invariant perturbations. In the conformal coupling case, this model predicts that the tensor mode of the perturbation (gravity wave) is strongly depressed.Comment: 9 page

    Stochastic Gravity: Theory and Applications

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    Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel. In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime, compute the two-point correlation functions of these perturbations and prove that Minkowski spacetime is a stable solution of semiclassical gravity. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a black hole and describe the metric fluctuations near the event horizon of an evaporating black holeComment: 100 pages, no figures; an update of the 2003 review in Living Reviews in Relativity gr-qc/0307032 ; it includes new sections on the Validity of Semiclassical Gravity, the Stability of Minkowski Spacetime, and the Metric Fluctuations of an Evaporating Black Hol

    Facing medical care problems of victims of sexual violence in Goma/Eastern Democratic Republic of the Congo

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    <p>Abstract</p> <p>Background</p> <p>Since 1998, the Eastern Democratic Republic of the Congo has been torn by a military conflict. A particular atrocity of the war is widespread sexual violence.</p> <p>Methods</p> <p>In this combined retrospective analysis and prospective survey, we sought to identify hospital facilities and resources available to treat victims of sexual violence in Goma, the capital city of the North Kivu province.</p> <p>Results</p> <p>Of twenty-three acute care hospitals registered in the area of Goma, four (17%) regularly cared for victims of sexual violence. One hospital had all resources always available to appropriately care for victims of sexual violence. From Jan 2009 until Oct 2010, 7,048 females sought medical care because of physical or psychological sequelae from sexual violence in the four hospitals of Goma. Only half of the hospitals had physicians specialized in gynaecology or gynaecological surgery available. Similarly, anaesthetists and psychiatrists/psychologists were available in two (50%) and one (25%) hospital, respectively. Post-discharge care facilities, material resources, such as surgical and anaesthesiological equipment and drugs, were inconsistently available in the hospitals caring for sexually abused females. At one selected hospital, acyclovir and/or antibiotics were administered to 1,202 sexually abused females (89.5%), whereas post-exposure HIV prophylaxis and surgery because of vesico-vaginal fistula was provided to only 75 (5.6%) and 121 (9%) patients, respectively.</p> <p>Conclusions</p> <p>This study provides data that only few hospitals in Goma care for victims of sexual violence. In addition, these hospitals suffer from a relevant shortage of human and material resources to provide adequate care for sexually abused females. Aside from establishment of adequate protection strategies, steps must be taken to increase the availability of trained health care professionals and resources to provide adequate care for victims of sexual violence in Goma and the North Kivu province.</p

    Equivalent forms of Dirac equations in curved spacetimes and generalized de Broglie relations

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    One may ask whether the relations between energy and frequency and between momentum and wave vector, introduced for matter waves by de Broglie, are rigorously valid in the presence of gravity. In this paper, we show this to be true for Dirac equations in a background of gravitational and electromagnetic fields. We first transform any Dirac equation into an equivalent canonical form, sometimes used in particular cases to solve Dirac equations in a curved spacetime. This canonical form is needed to apply the Whitham Lagrangian method. The latter method, unlike the WKB method, places no restriction on the magnitude of Planck's constant to obtain wave packets, and furthermore preserves the symmetries of the Dirac Lagrangian. We show using canonical Dirac fields in a curved spacetime, that the probability current has a Gordon decomposition into a convection current and a spin current, and that the spin current vanishes in the Whitham approximation, which explains the negligible effect of spin on wave packet solutions, independent of the size of Planck's constant. We further discuss the classical-quantum correspondence in a curved spacetime based on both Lagrangian and Hamiltonian formulations of the Whitham equations. We show that the generalized de Broglie relations in a curved spacetime are a direct consequence of Whitham's Lagrangian method, and not just a physical hypothesis as introduced by Einstein and de Broglie, and by many quantum mechanics textbooks.Comment: PDF, 32 pages in referee format. Added significant material on canonical forms of Dirac equations. Simplified Theorem 1 for normal Dirac equations. Added section on Gordon decomposition of the probability current. Encapsulated main results in the statement of Theorem

    Prevalence and Correlates of Common Mental Disorders among Mothers of Young Children in Kilimanjaro Region of Tanzania.

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    Although poor maternal mental health is a major public health problem, with detrimental effects on the individual, her children and society, information on its correlates in low-income countries is sparse. This study investigates the prevalence of common mental disorders (CMD) among at-risk mothers, and explores its associations with sociodemographic factors. This population-based survey of mothers of children aged 0-36 months used the 14-item Shona Symptom Questionnaire (SSQ). Mothers whose response was "yes" to 8 or more items on the scale were defined as "at risk of CMD." Of the 1,922 mothers (15-48 years), 28.8% were at risk of CMD. Risk of CMD was associated with verbal abuse, physical abuse, a partner who did not help with the care of the child, being in a polygamous relationship, a partner with low levels of education, and a partner who smoked cigarettes. Cohabiting appeared to be protective. Taken together, our results indicate the significance of the quality of relations with one's partner in shaping maternal mental health. The high proportion of mothers who are at risk of CMD emphasizes the importance of developing evidence-based mental health programmes as part of the care package aimed at improving maternal well-being in Tanzania and other similar settings
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