3,441 research outputs found
Species status of Neisseria gonorrhoeae: Evolutionary and epidemiological inferences from multilocus sequence typing
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited - Copyright @ 2007 Bennett et al; licensee BioMed Central Ltd.Background: Various typing methods have been developed for Neisseria gonorrhoeae, but none provide the combination of discrimination, reproducibility, portability, and genetic inference that allows the analysis of all aspects of the epidemiology of this pathogen from a single data set. Multilocus sequence typing (MLST) has been used successfully to characterize the related organisms Neisseria meningitidis and Neisseria lactamica. Here, the same seven locus Neisseria scheme was used to characterize a diverse collection of N. gonorrhoeae isolates to investigate whether this method would allow differentiation among isolates, and to distinguish these three species. Results: A total of 149 gonococcal isolates were typed and submitted to the Neisseria MLST database. Although relatively few (27) polymorphisms were detected among the seven MLST loci, a total of 66 unique allele combinations (sequence types, STs), were observed, a number comparable to that seen among isolate collections of the more diverse meningococcus. Patterns of genetic variation were consistent with high levels of recombination generating this diversity. There was no evidence for geographical structuring among the isolates examined, with isolates collected in Liverpool, UK, showing levels of diversity similar to a global collection of isolates. There was, however, evidence that populations of N. meningitidis, N. gonorrhoeae and N. lactamica were distinct, with little support for frequent genetic recombination among these species, with the sequences from the gdh locus alone grouping the species into distinct clusters. Conclusion: The seven loci Neisseria MLST scheme was readily adapted to N. gonorrhoeae isolates, providing a highly discriminatory typing method. In addition, these data permitted phylogenetic and population genetic inferences to be made, including direct comparisons with N. meningitidis and N. lactamica. Examination of these data demonstrated that alleles were rarely shared among the three species. Analysis of variation at a single locus, gdh, provided a rapid means of identifying misclassified isolates and determining whether mixed cultures were present.This study is funded by the Wellcome Trust and European Unio
The epidemiology of diarrhoeal disease in children at Queen Elizabeth Central Hospital, Blantyre, Malawi, 1994-1997
Diarrhoeal disease (DD) is a leading cause of childhood morbidity and mortality in developing countries throughout the world. To begin to understand the burden of DD at Queen Elizabeth Central Hospital (QECH), its seasonality and age distribution, we reviewed inpatient and outpatient records for cases of gastroenteritis between 1994 and 1997. Annually, DO. accounted for an average of 7,300 attendances to the; Under 5's rehydration clinic, 1219 paediatric admissions (12% of all hospitalisations) and 183 deaths in hospitalised children (19% of total). A distinct seasonal pattern was identified with monthly peaks for DD occurring between October to January. Over 75% children (inpatients and outpatients) were below two years of age. During the study period, an increase in the number of outpatient attendances for DD was observed. In contrast, the number of children with a more severe outcome, hospitalisation or death, declined during the study period. This is likely to be explicable by the increasing and appropriate use of oral rehydration therapy. We conclude that DD is a substantial cause of morbidity and mortality in Malawian children. Further studies of the patterns of DD at QECH will be necessary to assess the impact ofDD control programmes
Concentrations of trace metals (lead, iron, copper and zinc) in crops harvested in some oil prospecting locations in Rivers State, Nigeria
Concentrations of the trace metals lead, iron, copper and zinc were estimated in crops harvested in some oil prospecting locations in Rivers State, Nigeria. The  locations were; Agbada-Aluu (AA), Ebocha (EB), Idu Ekpeye (IE), Obagi (OB) and Trans Amadi Layout (TA), with the Teaching and Research Farm of Rivers State University of Science and Technology, Port Harcourt as control. Crops investigated were cassava (Manihot esculenta), cocoyam (Colocasia esculenta), okra (Hibiscus esculentus), pumpkin leaves (Telfairia occidentalis) and waterleaf (Talinum traingulare). Results of the mean lead concentrations were from 1.1ÎŒg/g in cocoyam to 9.1 ÎŒg/g in okro, showing higher trends in the industrialized areas. While cocoyam had the lowest lead concentration, the concentration rest of the crops did not differ significantly from one another. Crops from locations TA, OB, IE and EB had significantly higher concentrations of lead, although IE, AA and TF were not significantly different from one another. Mean concentrations of iron were between 40 ÎŒg/g in cassava from TF, and 651 ÎŒg/g in pumpkin leaves from TA - the industrial base of Rivers State - reflecting a high level of pollution from the various industries in that location. Differences in concentration of iron in crops showed pumpkin leaves to have the highest level of iron, followed by the other green vegetables â waterleaf and okra - although no significant differences occurred between okra, cocoyam and cassava. Copper concentrations were between 4.4 ÎŒg/g in cocoyam from locations TF and 23 ÎŒg/g in pumpkin leaves from TA. Pumpkin leaves had the highest concentrations of copper, followed by okra, then waterleaf, with cocoyam and cassava having the least significant levels. Zinc concentrations in crops were between 29 ÎŒg/g in cocoyam from TF to 240 ÎŒg/g in pumpkin leaves from EB. Pumpkin leaves and okra contained the highest levels of the metal, followed by waterleaf, then cassava and finally cocoyam. In terms of location, TA, OB and EB had the highest concentrations in crops, the least occurring in TF and AA. These results reflect higher concentrations of metals in crops from the industrialized locations, with the green vegetables, particularly pumpkin leaves, having the highest uptake, while cocoyam invariably had the least. These findings give cause for concern, particularly as heavy metals are bio-accumulative in the system and portend a serious health risk to man and animals.Key Words: Trace metals, concentrations, food crops, oil prospecting locations Des concentrations de mĂ©taux en traces (plomb, fer, cuivre et zinc) ont Ă©tĂ©Â Ă©valuĂ©es dans des cultures rĂ©coltĂ©es dans certains endroits de prospection de pĂ©trole dans lâEtat de Rivers State, Nigeria. Ces endroits Ă©taient Agbada-Aluu (AA), Ebocha (EB), Idu Ekpeye (IE), Obagi (OB) et Trans Amadi Layout (TA), avec la ferme dâenseignement et de recherche de lâUniversitĂ© des Sciences et Technologie de Rivers State, avec Port Harcourt comme contrĂŽle. Les cultures qui ont fait lâobjet dâanalyse Ă©taient le manioc, (Manihot esculenta), la patate douce (Colocasia esculenta), le gombo, (Hibiscus esculentus), les feuilles de courge (Telfairia occidentalis) et un lĂ©gume hydrophile (Talinum traingulare). Les rĂ©sultats de la moyenne des concentrations de plomb se situaient entre 1,1ÎŒg/g dans la patate douce et 9,1 ÎŒg/g dans le gombo, ce qui montre de plus hautes tendances dans les rĂ©gions industrialisĂ©es. Alors que la patate douce avait la plus faible concentration, le reste des cultures ne diffĂ©raient pas considĂ©rablement lâune de lâautre. Les cultures provenant des rĂ©gions TA, OB, IE et EB avaient des concentrations nettement supĂ©rieures en plomb, tandis que celles de IE, AA et TF ne diffĂ©raient pas beaucoup lâune et de lâautre. Les concentrations moyennes de fer se situaient entre 40ÎŒg/g dans le manioc de TF, et 651 ÎŒg/g dans les feuilles de courge de TA â la base industrielle de Rivers Stateâ ce qui reflĂšte un niveau Ă©levĂ© de pollution des diffĂ©rentes industries de cette rĂ©gion. Des diffĂ©rences de concentration de fer dans les cultures ont montrĂ© que les feuilles de courge ont la plus haute teneur en fer, suivies par les autres lĂ©gumes verts â le lĂ©gume hydrophile et le gombo â bien quâaucune grande diffĂ©rence ne se soit produite entre le gombo, la patate douce et le manioc. Des concentrations de cuivre se situaient entre 4,4 ÎŒg/g dans la patate douce des rĂ©gions TF et 23 ÎŒg/g dans les feuilles de courge des rĂ©gions TA. Les feuilles de courge avaient les plus hautes concentrations de cuivre, suivies par le gombo, puis le lĂ©gume hydrophile, tandis que la patate douce et le manioc avaient les niveaux les plus bas. Les concentrations de zinc dans les cultures se situaient entre 29 ÎŒg/g dans la patate douce de TF et 240 ÎŒg/g dans les feuilles de courge de EB. Les feuilles de courge et le gombo contenaient les niveaux les plus Ă©levĂ©s de ce mĂ©tal, puis le lĂ©gume hydrophile, ensuite le manioc et finalement la patate douce. En ce qui concerne le lieu, TA, OB et EB avaient les concentrations les plus hautes dans les cultures, les concentrations les plus basses se trouvaient dans TF et AA. Ces rĂ©sultats reflĂštent des concentrations de mĂ©taux plus Ă©levĂ©es dans les cultures des rĂ©gions industrialisĂ©es, tandis que les lĂ©gumes verts -particuliĂšrement les feuilles de courgeavaient la plus haute assimilation, et la patate douce avait invariablement la plus faible. Ces rĂ©sultats suscitent des apprĂ©hensions, particuliĂšrement parce que les mĂ©taux lourds sont bio-cumulatifs dans le systĂšme et quâils prĂ©sagent de sĂ©rieux risques sanitaires pour les hommes et les animaux.Mots-clĂ©s: MĂ©taux en traces, concentrations, denrĂ©es alimentaires, endroits de prospection de pĂ©trole
In vitro synergy and enhanced murine brain penetration of saquinavir coadministered with mefloquine.
Highly active antiretroviral therapy has substantially improved prognosis in human immunodeficiency virus (HIV). However, the integration of proviral DNA, development of viral resistance, and lack of permeability of drugs into sanctuary sites (e.g., brain and lymphocyte) are major limitations to current regimens. Previous studies have indicated that the antimalarial drug chloroquine (CQ) has antiviral efficacy and a synergism with HIV protease inhibitors. We have screened a panel of antimalarial compounds for activity against HIV-1 in vitro. A limited efficacy was observed for CQ, mefloquine (MQ), and mepacrine (MC). However, marked synergy was observed between MQ and saquinavir (SQV), but not CQ in U937 cells. Furthermore, enhancement of the antiviral activity of SQV and four other protease inhibitors (PIs) by MQ was observed in MT4 cells, indicating a class specific rather than a drug-specific phenomenon. We demonstrate that these observations are a result of inhibition of multiple drug efflux proteins by MQ and that MQ also displaces SQV from orosomucoid in vitro. Finally, coadministration of MQ and SQV in CD-1 mice dramatically altered the tissue distribution of SQV, resulting in a >3-fold and >2-fold increase in the tissue/blood ratio for brain and testis, respectively. This pharmacological enhancement of in vitro antiviral activity of PIs by MQ now warrants further examination in vivo
Genotype analysis of Escherichia coli strains isolated from children and chickens living in close contact
Escherichia coli isolates from rectal swabs from 62 chickens and stools from 42 children living in close contact with chickens on the same farms in Kiambu district, Kenya, were compared for their genetic relatedness. Antibiotic susceptibility profiles broadly categorized isolates from the children and from the chickens into two separate clusters: the majority (144; 85.5%) of the E. coil isolates from children were multidrug resistant, while the majority (216; 87.1%) of the E. coli isolates from chickens were either fully susceptible or resistant only to tetracycline. Sixty- and 100- to 110- MDA plasmids were found to encode the transferable resistance to co- trimoxazole and tetracycline. HindIII restriction endonuclease digestion of the 60- and 100- to 110-MDA plasmids produced four distinct patterns for isolates from children and three distinct patterns for isolates from chickens. XbaI digestion of genomic DNA followed by pulsed-field gel electrophoresis (PFGE) analysis produced 14 distinct clusters. There were six distinct PFGE clusters among the isolates from children, while among the isolates from chickens there were seven distinct clusters. Only one PFGE cluster contained isolates from both children and chickens, with the isolates displaying an approximately 60% coefficient of similarity. This study showed that although several different genotypes of E. coli were isolated from children and chickens from the same farms, the E. coli strains from these two sources were distinct
Transoral laser surgery for laryngeal carcinoma: has Steiner achieved a genuine paradigm shift in oncological surgery?
Transoral laser microsurgery applies to the piecemeal removal of malignant tumours of the upper aerodigestive tract using the CO2 laser under the operating microscope. This method of surgery is being increasingly popularised as a single modality treatment of choice in early laryngeal cancers (T1 and T2) and occasionally in the more advanced forms of the disease (T3 and T4), predomi- nantly within the supraglottis.
Thomas Kuhn, the American physicist turned philosopher and historian of science, coined the phrase âparadigm shiftâ in his groundbreaking book The Structure of Scientific Revolutions. He argued that the arrival of the new and often incompatible idea forms the core of a new paradigm, the birth of an entirely new way of thinking. This article discusses whether Steiner and col- leagues truly brought about a paradigm shift in oncological surgery.
By rejecting the principle of en block resection and by replacing it with the belief that not only is it oncologically safe to cut through the substance of the tumour but in doing so one can actually achieve better results, Steiner was able to truly revolutionise the man- agement of laryngeal cancer. Even though within this article the repercussions of his insight are limited to the upper aerodigestive tract oncological surgery, his willingness to question other peoplesâ dogma makes his contribution truly a genuine paradigm shift
PSK4 COST-EFFECTIVENESS OF TOPICAL CALCIPOTRIOL/BETAMETHASONE DIPROPIONATE TWOCOMPOUND PRODUCT IN A SCOTTISH CARE MODEL
PSK4 COST-EFFECTIVENESS OF TOPICAL CALCIPOTRIOL/BETAMETHASONE DIPROPIONATE TWOCOMPOUND PRODUCT IN A SCOTTISH CARE MODEL
Aprovada pel gerent de l'Institut Municipal d'Hisenda el 01-07-200
Prevalence of Group A beta-haemolytic Streptococcus isolated from children with acute pharyngotonsillitis in Aden, Yemen.
OBJECTIVES: To estimate the prevalence of Group A beta-haemolytic streptococcus (GAS) and non-GAS infections among children with acute pharyngotonsillitis in Aden, Yemen, to evaluate the value of a rapid diagnostic test and the McIsaac score for patient management in this setting and to determine the occurrence of emm genotypes among a subset of GAS isolated from children with acute pharyngotonsillitis and a history of acute rheumatic fever (ARF) or rheumatic heart disease (RHD). METHODS: Group A beta-haemolytic streptococcus infections in school-aged children with acute pharyngotonsillitis in Aden, Yemen, were diagnosed by a rapid GAS antigen detection test (RADT) and/or GAS culture from a throat swab. The RADT value and the McIsaac screening score for patient management were evaluated. The emm genotype of a subset of GAS isolates was determined. RESULTS: Group A beta-haemolytic streptococcus pharyngotonsillitis was diagnosed in 287/691 (41.5%; 95% CI 37.8-45.3) children. Group B, Group C and Group G beta-haemolytic streptococci were isolated from 4.3% children. The RADT had a sensitivity of 238/258 (92.2%) and specificity of 404/423 (95.5%) against GAS culture. A McIsaac score of â„4 had a sensitivity of 93% and a specificity of 82% for confirmed GAS infection. The emm genotypes in 21 GAS isolates from children with pharyngitis and a history of ARF and confirmed RHD were emm87 (11), emm12 (6), emm28 (3) and emm5 (1). CONCLUSION: This study demonstrates a very high prevalence of GAS infections in Yemeni children and the value of the RADT and the McIsaac score in this setting. More extensive emm genotyping is necessary to understand the local epidemiology of circulating strains
Stem cells of the lower limb: Their role and potential in management of critical limb ischemia.
Peripheral arterial occlusive disease (PAOD) contributes to decreased exercise tolerance, poor balance, impaired proprioception, muscle atrophy and weakness, with advanced cases resulting in critical limb ischemia (CLI) where the viability of the limb is threatened. Patients with a diagnosis of CLI have a poor life expectancy due to concomitant cardio and cerebrovascular diseases. The current treatment options to avoid major amputation by re-establishing a blood supply to the limb generally have poor outcomes. Human skeletal muscle contains both multipotent stem cells and progenitor cells and thus has a capacity for regeneration. Phase I and II studies involving transplantation of bone marrow-derived progenitor cells into CLI limbs show positive effects on wound healing and angiogenesis; the increase in quiescent satellite cell numbers observed in CLI muscle may also provide a sufficient in vivo source of resident stem cells. These indigenous cells have been shown to be capable of forming multiple mesodermal cell lineages aiding the repair and regeneration of chronically ischemic muscle. They may also serve as a repository for autologous transplantation. The behavior and responses of the stem cell population in CLI is poorly understood and this review tries to elucidate the potential of these cells and their future role in the management of CLI
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