Uncommon cause of chest pain in a renal transplantation patient with autosomal dominant polycystic kidney disease: a case report

Autosomal dominant polycystic kidney disease (ADPKD) is a common cause of end-stage renal disease (ESRD) and, because of its intrinsic systemic involvement, its treatment can be a medical and surgical challenge. This condition is often associated with the presence of hepatic cysts and their prevalence generally increases with age. Most patients remain asymptomatic, but some of these will develop complications associated with enlargement and infection of their cysts. Chest pain is a rare manifestation of these complications and, after exclusion of more common cardiovascular and pulmonary causes, should raise the suspicion of an infected hepatic cyst in these patients. We report the case of a 62-year-old male who underwent a kidney transplantation from a cadaveric donor in 1997 (etiology of the ESRD was ADPKD), and was admitted to the emergency department with complaints of chest pain radiating to both shoulders and the interscapular region. An echocardiogram was showed compression of the right atrium by a large liver cyst without associated ventricular dysfunction. Computer tomography-guided drainage of the cyst was performed and an Enterobacter aerogenes sensitive to carbamapenemes was isolated from respective cultures. The patient presented a favorable clinical outcome with prolonged administration of antibiotic therapy according to the antibiotic susceptibility testing. There was no need for surgical intervention.

A neural network for shortest path computation

This paper presents a new neural network to solve the shortest path problem for inter-network routing. The proposed solution extends the traditional single-layer recurrent Hopfield architecture introducing a two-layer architecture that automatically guarantees an entire set of constraints held by any valid solution to the shortest path problem. This new method addresses some of the limitations of previous solutions, in particular the lack of reliability in what concerns successful and valid convergence. Experimental results show that an improvement in successful convergence can be achieved in certain classes of graphs. Additionally, computation performance is also improved at the expense of slightly worse results.

Methylglyoxal causes structural and functional alterations in adipose tissue independently of obesity

CONTEXT

Adipose tissue is one of the first organs to develop insulin resistance even with moderate BMI. However, the contribution of developing hyperglycaemia and concomitant methylglyoxal increment to tissue dysfunction during type 2 diabetes progression was not addressed before.

METHODS

Young and aged Wistar and Goto-Kakizaki rats (non-obese model of type 2 diabetes) and a group of MG-treated W rats were used to investigate the chronic effects of hyperglycaemia and ageing and specifically MG-induced mechanisms.

RESULTS

Diabetic and aged rats showed decreased adipose tissue irrigation and interstitial hypoxia. Hyperglycaemia of diabetic rats leaded to fibrosis and accumulation of PAS-positive components, exacerbated in aged animals, which also showed decreased hipoadiponectinemia, increased MCP-1 expression and macrophage infiltration to glycated fibrotic regions. MG leaded to increased free fatty acids, hipoadiponectinemia, decreased irrigation, hypoxia and macrophage recruitment for glycated fibrotic regions.

CONCLUSIONS

MG contributes to dysfunction of adipose tissue during type 2 diabetes progression.

Delays in seeking treatment for symptomatic tuberculosis in Sabah, East Malaysia: factors for patient delay

SETTING

The state of Sabah contributes one third of the tuberculosis (TB) cases in Malaysia.

OBJECTIVE

To collect information on factors that affect the time period from the onset of symptoms to first contact with health care providers, whether private or government.

DESIGN

A cross-sectional study using a pre-tested questionnaire was conducted among 296 newly registered smear-positive TB patients in 10 districts in Sabah. Univariable and multivariable analyses were used to determine which risk factors were associated with patient delay (>30 days) and 'extreme' patient delay (>90 days).

RESULTS

The percentage of patients who sought treatment after 30 and 90 days was respectively 51.8% (95%CI 45.7-57.9) and 23.5% (95%CI 18.6-29.0). The strongest factors associated with patient delay and 'extreme' patient delay was when the first choice for treatment was a non-government health facility and in 30-39-year-olds. 'Extreme' patient delay was also weakly associated, among other factors, with comorbidity and livestock ownership.

CONCLUSION

Delay and extreme delay in seeking treatment were more common when the usual first treatment choice was a non-government health facility. Continuous health education on TB aimed at raising awareness and correcting misconceptions is needed, particularly among those who use non-government facilities.

Rapid ecological assessment of benthic indicators of water quality: a successful capacity-building experience for Brazilian postgraduate students in ecology

Rapid Ecological Assessment protocols are important tools for the training of postgraduate students, as well as the collection of data on poorly-known and protected areas with the potential for the preservation of water supplies for urban areas. The objective of this study was to perform a survey of water quality and diversity of benthic macroinvertebrates in two sub-basins at the Mata do Junco Wildlife Refuge in the Brazilian state of Sergipe. The collection of data in the field, laboratory processing, and the interpretation and discussion of data were conducted in groups by students from two postgraduate programmes in Ecology and Conservation (UFMG and UFS), personnel of the state environment agency (SEMARH), school teachers from the local town of Capela, and members of the reserve's voluntary fire brigade. The results of the assessment were organised, analysed, and presented at the reserve headquarters in the form of posters, for the development of environmental education activities with pupils from local schools, as well as contributing to a SEMARH seminar. Samples were characterised by distinct taxonomic compositions and diversity, as confirmed by MDS and additive partitioning of diversity analyses. The gravel substrate presented the lower mean taxonomic richness in each sampling unit (a1 = 28%), while the average difference among samples (b1 diversity) was elevated for both substrates (39% for leaf litter, 41% for gravel), reflecting the pronounced variation among samples, even adjacent ones within the same stream. Diversity between streams was lower in the case of leaf litter in comparison with gravel (b2 = 21 and 31%, respectively). A total of 57 fish specimens were collected with a predominance of individuals of the orders Characiformes (62%) and Perciformes (21%). This rapid ecological assessment confirmed the importance of the conservation unit and emphasised the need for its continuation, given its importance for the maintenance of water quality and its other ecological services, such as the conservation of the region's aquatic biodiversity and providing the local town of Capela (circa 20,000 inhabitants) with its water supply, the Mata do Junco being its only source.

Li(+)- and Eu(³+)-doped poly(ε-caprolactone)/siloxane biohybrid electrolytes for electrochromic devices

The sol-gel process has been successfully combined with the "mixed cation" effect to produce novel luminescent and ion conducting biohybrids composed of a diurethane cross-linked poly(ε-caprolactone) (PCL530)/siloxane hybrid network (PCL stands for the poly(ε-caprolactone) biopolymer and 530 is the average molecular weight in gmol(-1)) doped with a wide range of concentrations of lithium and europium triflates (LiCF(3)SO(3) and Eu(CF(3)SO(3))(3), respectively) (molar ratio of ca. 50:50). The hybrid samples are all semicrystalline: whereas at n = 52.6 and 27.0 (n, composition, corresponds to the number of (C(═O)(CH(2))(5)O) repeat units of PCL(530) per mixture of Li(+) and Eu(3+) ions) a minor proportion of crystalline PCL(530) chains is present, at n = 6.1, a new crystalline phase emerges. The latter electrolyte is thermally stable up to 220 °C and exhibits the highest conductivity over the entire range of temperatures studied (3.7 × 10(-7) and 1.71 × 10(-4) S cm(-1) at 20 and 102 °C, respectively). According to infrared spectroscopic data, major modifications occur in terms of hydrogen bonding interactions at this composition. The electrochemical stability domain of the biohybrid sample with n = 27 spans more than 7 V versus Li/Li(+). This sample is a room temperature white light emitter. Its emission color can be easily tuned across the Commission Internationale d'Éclairage (CIE) chromaticity diagram upon simply changing the excitation wavelength. Preliminary tests performed with a prototype electrochromic device (ECD) comprising the sample with n = 6.1 as electrolyte and WO(3) as cathodically coloring layer are extremely encouraging. The device exhibits switching time around 50 s, an optical density change of 0.15, good open circuit memory under atmospheric conditions (ca. 1 month) and high coloration efficiency (577 cm(2) C(-1) in the second cycle).

Metformin and atorvastatin combination further protect the liver in type 2 diabetes with hyperlipidaemia

BACKGROUND

non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes are associated with dyslipidaemia, inflammation and oxidative stress. However, the pathophysiology of NAFLD in type 2 diabetes with hyperlipidaemia is not fully known, as well as the utility of the commonly prescribed anti-diabetic and lipid-lowering drugs in ameliorating liver injury markers.

METHODS

hepatic complications of type 2 diabetes with hyperlipidaemia and the effects of atorvastatin and metformin, isolated and in association, in systemic and hepatic inflammatory and oxidative stress markers were tested using genetic type 2 diabetic Goto-Kakizaki rats fed with a high-fat diet.

RESULTS

the high-fat diet aggravated the overall metabolic state and the hepatic markers of injury. All treatments decreased fasting glycaemia, insulin resistance and free fatty acid levels. Combined treatment further decreased C-reactive protein (CRP), adiponectin, liver tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6), systemic and hepatic oxidative stress and portal inflammation.

CONCLUSIONS

our data provides evidence of a greater benefit with a combination of atorvastatin and metformin in improving liver injury in type 2 diabetes with hyperlipidaemia.

Long-term periodic anthelmintic treatments are associated with increased allergen skin reactivity

Background

The low prevalence of allergic disease in the rural tropics has been attributed to the protective effects of chronic helminth infections. There is concern that treatment-based control programmes for these parasites may lead to an increase in the prevalence of allergic diseases.

Objective

We measured the impact of 15–17 years of anthelmintic treatment with ivermectin on the prevalence of allergen skin test reactivity and allergic symptoms in school-age children.

Methods

The prevalence of allergen skin test reactivity, exercise-induced bronchospasm and allergic symptoms was compared between school-age children living in communities that had received community-based treatments with ivermectin (for onchocerciasis control) for a period of 15–17 years with those living in geographically adjacent communities that had received no ivermectin.

Results

The prevalence of allergen skin test reactivity was double in children living in treated communities compared with those in untreated communities (16.7% vs. 8.7%, adjusted OR 2.10, 95% CI 1.50–2.94, P<0.0001), and the effect was mediated partly by a reduced prevalence of Trichuris trichiura among treated children. Ivermectin treatments were associated with an increased prevalence of recent eczema symptoms (adjusted OR 2.24, 95% CI 1.05–4.78, P=0.04) but not symptoms of asthma or rhino-conjunctivitis. The effect on eczema symptoms was not associated with reductions in geohelminth infections.

Conclusion

Long-term periodic treatments with ivermectin were associated with an increased prevalence of allergen skin test reactivity. There was some evidence that treatment was associated with an increased prevalence of recent eczema symptoms but not those of asthma or rhino-conjunctivitis.

Cite this as: P. Endara, M. Vaca, M. E. Chico, S. Erazo, G. Oviedo, I. Quinzo, A. Rodriguez R. Lovato, A.-L. Moncayo, M. L. Barreto, L. C. Rodrigues and P. J. Cooper, Clinical & Experimental Allergy, 2010 (40) 1669–1677.

Physiological characterisation of the efflux pump system of antibiotic-susceptible and multidrug-resistant Enterobacter aerogenes

Enterobacter aerogenes predominates amongst Enterobacteriaceae species that are increasingly reported as producers of extended-spectrum beta-lactamases. Although this mechanism of resistance to beta-lactams is important, other mechanisms bestowing a multidrug-resistant (MDR) phenotype in this species are now well documented. Amongst these mechanisms is the overexpression of efflux pumps that extrude structurally unrelated antibiotics prior to their reaching their targets. Interestingly, although knowledge of the genetic background behind efflux pumps is rapidly advancing, few studies assess the physiological nature of the overall efflux pump system of this, or for that matter any other, bacterium. The study reported here evaluates physiologically the efflux pump system of an E. aerogenes ATCC reference as well as two strains whose MDR phenotypes are mediated by overexpressed efflux pumps. The activities of the efflux pumps in these strains are modulated by pH and glucose, although the effects of the latter are essentially restricted to pH 8, suggesting the presence of two general efflux pump systems, i.e. proton-motive force-dependent and ABC transporter types, respectively.

Interannual variability of phytoplankton in the main rivers of the Upper Paraná River floodplain, Brazil: influence of upstream reservoirs

The interannual variation of phytoplankton communities in the three main rivers of the Upper Paraná River floodplain is evaluated in relation to changes in the hydrosedimentological regime. These changes are a result of climatic variability and the formation of Porto Primavera Reservoir, located at the upper Paraná River. Phytoplankton species richness and density were investigated in rivers during a prior period (1993-1994) and eight years after reservoir impoundment (2000-2007). Multiple analyses were conducted to test the differences between these time periods in order to find predictor variables for phytoplankton attributes. A total of 454 phytoplanktonic taxa were found. The regression analysis revealed significant differences between periods. In the years following construction of the Porto Primavera dam, species richness was lower in the Paraná River and density was higher in the three rivers. In general, the algal density decreased from 2005 to 2007. Diatoms and cyanobacteria contributed significantly to the total density during the period from March 1993 to February 1994. The years 2000-2007 presented the lowest diatom contribution to species richness and the highest cyanobacteria contribution. From 2000 on, cryptomonads and cyanobacteria dominated. The interannual variability of phytoplankton was probably influenced by changes in hydrosedimentological regime due to climatic variations (La Niña and El Niño-Southern Oscillation events--ENSO) and the operational procedures associated with an upstream reservoirs. Studies on climatic variability and its effects on hydrosedimentological regimes of the Paraná, Baía and Ivinhema rivers and the biota therein are necessary to obtain subsidies for management, including decisions related to the operation of dams upstream and downstream of the study area, with the purpose of minimizing risks to the Environmental Protection Area.

Identification of nontuberculous mycobacteria in clinical samples using molecular methods: a 3-year study

Nontuberculous mycobacteria (NTM) are being increasingly isolated in clinical laboratories and present technical and therapeutic challenges. In the present study, we report our experience with the identification of NTM received from 12 Lisbon hospitals over a 3-year period using GenoType Mycobacterium (CM/AS) assays (HAIN Lifescience GmbH, Nehren, Germany). Together, the two kits identified 96.6% of all NTM isolates tested. Among the 18 NTM species identified, Mycobacterium avium complex was the most frequent, although it accounted for only 34% of all NTM. Introducing these methods for the rapid identification of NTM highlights the importance of NTM as potential pathogens and assisted the selection of adequate therapy.

An AcrAB-mediated multidrug-resistant phenotype is maintained following restoration of wild-type activities by efflux pump genes and their regulators

In this study, we aimed to answer the following question: 'How does a bacterium become so resistant to a given antibiotic even though the levels of antibiotic to which it has become resistant remained constant in the patient?'Escherichia coli AG100 strain induced to high-level resistance due to overexpression of an AcrAB efflux pump was serially cultured in 10mg/L tetracycline for 60 passages. Between each passage it became increasingly resistant to tetracycline, beta-lactams and quinolones with concomitant restoration of wild-type AcrAB activity. Because the multidrug-resistant phenotype could not be reversed with transfer to drug-free medium or with efflux pump inhibitors, it may have resulted from activation of a 'mutator gene' system that reduced the 'energy consumption' associated with an overexpressed efflux pump system.

Relatedness and HLA-DRB1 typing may discriminate the magnitude of the genetic susceptibility to tuberculosis using a household contact model

BACKGROUND

Tuberculosis clusters in families may be due to increased household exposure, shared genetic factors, or both. Household contact studies are useful to control exposure because socioeconomic and environmental conditions are similar to all subjects, allowing the evaluation of the contribution of relatedness to disease development.

METHODS

In this study, the familial aggregation of tuberculosis using relatedness and a specific inherited marker (HLA-DRB1) was evaluated. Fifty families, which had at least two cases of tuberculosis diagnosed within the past 5 years, were selected from a cohort of tuberculosis carried out in Recife, Brazil. The first case diagnosed was considered to be a primary case. The secondary attack rate of tuberculosis in household contacts was estimated according to the degree of relatedness. The relative risk of having tuberculosis based on the degree of relatedness household and the population attributable fraction to relatedness were also estimated. HLA-DRB1 typing and attributable etiologic/preventive fractions were calculated among sick and healthy household contacts.

RESULTS

Compared to unrelated contacts, the relative risk for tuberculosis adjusted for age was 1.38 (95% CI 0.86 to 2.21). Relatedness contributed 23% to the development of tuberculosis at the population levels. The HLA-DRB1*04 allele group (OR=2.44; p=0.0324; etiologic fraction=0.15) was overrepresented and the DRB1*15 allele group (OR=0.48; p=0.0488; protective fraction=0.19) was underrepresented among household contacts exhibiting tuberculosis. The presence of DRB1 shared alleles between primary cases and their contacts was a risk factor for tuberculosis (p=0.0281).

CONCLUSION

This household contact model together with the utilisation of two genetic variables permitted the evaluation of genetic factors contributing towards tuberculosis development.

Rapid reduction in hospitalisations after an intervention to manage severe asthma

Asthma is the third cause of hospitalisations due to clinical illnesses in Brazil. The Programme for Control of Asthma in Bahia (ProAR) leads an initiative in Salvador City (Brazil) to manage severe asthma for free. The aim of this study was to identify trends in asthma hospitalisation in the entire city and to evaluate the impact of ProAR. Information on asthma hospitalisations from 1998 to 2006 was collected. We analysed trends in Salvador (2.8 million inhabitants) before and after ProAR, taking pneumonia and myocardial infarction into account for local comparison. As an external control we obtained information on asthma from Recife, which is the most comparable Brazilian city. In Salvador, asthma hospital admissions declined by 82.3% (1998-2006). A greater proportion of this reduction (74%) occurred after 2003, in parallel with the implementation of ProAR. The reduction in asthma admissions in Recife was smaller. The rates of hospitalisation in 2006 were 2.25 per 10,000 inhabitants in Salvador and 17.06 in Recife. In Salvador, we found an inverse correlation between the provision of medication for asthma and hospitalisation (-0.801; p<0.0001). A rapid reduction in asthma admissions in the entire city of Salvador was associated with ProAR, a public health intervention targeting severe asthma.

Sequence-based and monoclonal antibody typing of Legionella pneumophila isolated from patients in Portugal during 1987-2008

The monoclonal antibodies and the sequence-based typing (SBT) are two methodologies widely used to characterise Legionella pneumophila strains serogroup 1 (sg1). In this study, we analysed the clinical strains received in two Portuguese laboratories since 1987, including the strains isolated in Portugal during the four years of the surveillance scheme for Legionnaires' disease implemented in 2004. In total, 63 clinical isolates of L. pneumophila sg1 were differentiated by SBT into 19 different sequence types. Ten of them were new in the SBT database of the European Working Group for Legionella Infections (EWGLI). As a result of the combination of the two methodologies, these strains were discriminated into 25 different profiles. This study enabled, for the first time in Portugal, not only to characterise the L. pneumophila sg1 clinical isolates, but also to create a database of Portuguese profiles for use in epidemiological surveillance efforts.

Periphytic algae of the Garças Lake, Upper Paraná River floodplain: comparing the years 1994 and 2004

The changes imposed by dams on hydrological regime, water transparence and nutrient concentrations downstream affect biodiversity in relation to species richness and specific composition of the community. The aim of this work was evaluate this effect on periphyton, comparing richness and composition of periphytic algae in the Garças Lake, Upper Paraná River floodplain, between the years 1994, before construction of the Porto Primavera Reservoir, and after its operation in 2004. This floodplain lake showed an increase in species, from 113 in 1994 to 159 in 2004. A few species, however, were common during the last year, dominated by Zygnemaphyceae and some Bacillariophyceae species. The increase in algal diversity in 2004 may be the result of the ability of the system to adapt to environmental changes. However, the large change in the periphyton species composition suggests further impacts on the food web, demanding continuity of long-term studies in order to determine their consequences on the biodiversity as a whole.