Towards a precise test for malaria diagnosis in the Brazilian Amazon: comparison among field microscopy, a rapid diagnostic test, nested PCR, and a computational expert system based on artificial neural networks

Abstract Background Accurate malaria diagnosis is mandatory for the treatment and management of severe cases. Moreover, individuals with asymptomatic malaria are not usually screened by health care facilities, which further complicates disease control efforts. The present study compared the performances of a malaria rapid diagnosis test (RDT), the thick blood smear method and nested PCR for the diagnosis of symptomatic malaria in the Brazilian Amazon. In addition, an innovative computational approach was tested for the diagnosis of asymptomatic malaria. Methods The study was divided in two parts. For the first part, passive case detection was performed in 311 individuals with malaria-related symptoms from a recently urbanized community in the Brazilian Amazon. A cross-sectional investigation compared the diagnostic performance of the RDT Optimal-IT, nested PCR and light microscopy. The second part of the study involved active case detection of asymptomatic malaria in 380 individuals from riverine communities in Rondônia, Brazil. The performances of microscopy, nested PCR and an expert computational system based on artificial neural networks (MalDANN) using epidemiological data were compared. Results Nested PCR was shown to be the gold standard for diagnosis of both symptomatic and asymptomatic malaria because it detected the major number of cases and presented the maximum specificity. Surprisingly, the RDT was superior to microscopy in the diagnosis of cases with low parasitaemia. Nevertheless, RDT could not discriminate the Plasmodium species in 12 cases of mixed infections (Plasmodium vivax + Plasmodium falciparum). Moreover, the microscopy presented low performance in the detection of asymptomatic cases (61.25% of correct diagnoses). The MalDANN system using epidemiological data was worse that the light microscopy (56% of correct diagnoses). However, when information regarding plasma levels of interleukin-10 and interferon-gamma were inputted, the MalDANN performance sensibly increased (80% correct diagnoses). Conclusions An RDT for malaria diagnosis may find a promising use in the Brazilian Amazon integrating a rational diagnostic approach. Despite the low performance of the MalDANN test using solely epidemiological data, an approach based on neural networks may be feasible in cases where simpler methods for discriminating individuals below and above threshold cytokine levels are available.

Ultrasonic tissue characterization of vulnerable carotid plaque: correlation between videodensitometric method and histological examination

Abstract Background To establish the correlation between quantitative analysis based on B-mode ultrasound images of vulnerable carotid plaque and histological examination of the surgically removed plaque, on the basis of a videodensitometric digital texture characterization. Methods Twenty-five patients (18 males, mean age 67 ± 6.9 years) admitted for carotid endarterectomy for extracranial high-grade internal carotid artery stenosis (≥ 70% luminal narrowing) underwent to quantitative ultrasonic tissue characterization of carotid plaque before surgery. A computer software (Carotid Plaque Analysis Software) was developed to perform the videodensitometric analysis. The patients were divided into 2 groups according to symptomatology (group I, 15 symptomatic patients; and group II, 10 patients asymptomatic). Tissue specimens were analysed for lipid, fibromuscular tissue and calcium. Results The first order statistic parameter mean gray level was able to distinguish the groups I and II (p = 0.04). The second order parameter energy also was able to distinguish the groups (p = 0,02). A histological correlation showed a tendency of mean gray level to have progressively greater values from specimens with < 50% to >75% of fibrosis. Conclusion Videodensitometric computer analysis of scan images may be used to identify vulnerable and potentially unstable lipid-rich carotid plaques, which are less echogenic in density than stable or asymptomatic, more densely fibrotic plaques.

Histological composition and progression of carotid plaque

Abstract Background To analyse histological composition and progression of carotid plaque. Methods Thirty-one patients (22 males, mean age 68.03 ± 7.3 years) admitted for carotid endarterectomy for extracranial high-grade internal carotid artery stenosis (≥ 70% luminal narrowing) were enrolled. The patients were divided into 2 groups according to symptomatology (group I, 17 symptomatic patients; and group II, 14 asymptomatic patients). A histological analysis and inflammatory cell quantification of each excised carotid plaque was made. Nine carotid arteries were removed from human cadavers that were not preselected for carotid artery disease. These specimens were used as a control tissue without any macroscopic signs of atherosclerotic plaques. Results Fifty eight percent of all carotid plaques were classified as complex plaque with possible surface defect, hemorrhage or thrombus. The inflammatory cells concentration did not differ between the two groups. All specimens from human cadavers were classified as preatheroma with extracellular lipid pools. Conclusion Asymptomatic and symptomatic patients could have the same histological components on their carotid plaques. Fibrotic and calcific plaques could become vulnerable as complex plaques with surface defect, hemorrhage and thrombus could remain silent. Asymptomatic carotid stenosis should be followed close with no invasive diagnostic methods and clinical evaluation.

Assessment of MMP-9, TIMP-1, and COX-2 in normal tissue and in advanced symptomatic and asymptomatic carotid plaques

Abstract Background Mature carotid plaques are complex structures, and their histological classification is challenging. The carotid plaques of asymptomatic and symptomatic patients could exhibit identical histological components. Objectives To investigate whether matrix metalloproteinase 9 (MMP-9), tissue inhibitor of MMP (TIMP), and cyclooxygenase-2 (COX-2) have different expression levels in advanced symptomatic carotid plaques, asymptomatic carotid plaques, and normal tissue. Methods Thirty patients admitted for carotid endarterectomy were selected. Each patient was assigned preoperatively to one of two groups: group I consisted of symptomatic patients (n = 16, 12 males, mean age 66.7 ± 6.8 years), and group II consisted of asymptomatic patients (n = 14, 8 males, mean age 67.6 ± 6.81 years). Nine normal carotid arteries were used as control. Tissue specimens were analyzed for fibromuscular, lipid and calcium contents. The expressions of MMP-9, TIMP-1 and COX-2 in each plaque were quantified. Results Fifty-eight percent of all carotid plaques were classified as Type VI according to the American Heart Association Committee on Vascular Lesions. The control carotid arteries all were classified as Type III. The median percentage of fibromuscular tissue was significantly greater in group II compared to group I (p < 0.05). The median percentage of lipid tissue had a tendency to be greater in group I than in group II (p = 0.057). The percentages of calcification were similar among the two groups. MMP-9 protein expression levels were significantly higher in group II and in the control group when compared with group I (p < 0.001). TIMP-1 expression levels were significantly higher in the control group and in group II when compared to group I, with statistical difference between control group and group I (p = 0.010). COX-2 expression levels did not differ among groups. There was no statistical correlation between MMP-9, COX-2, and TIMP-1 levels and fibrous tissue. Conclusions MMP-9 and TIMP-1 are present in all stages of atherosclerotic plaque progression, from normal tissue to advanced lesions. When sections of a plaque are analyzed without preselection, MMP-9 concentration is higher in normal tissues and asymptomatic surgical specimens than in symptomatic specimens, and TIMP-1 concentration is higher in normal tissue than in symptomatic specimens.

Body packing by rectal insertion of cocaine packets: a case report

Background: Body packing is used for international drug transport, immediate drug concealment during a police searching or introducing drugs inside prisons. Despite the high level of specialization of dealers who have started to manufacture more complex packs, up to 5% of patients could develop intoxication due to pack rupture. Bowel obstruction is another acute complication. Case presentation: A 27-year-old black male patient was sent to the hospital by court order for clinical evaluation and toxicological examination. The patient was conscious, oriented, had good color, normal arterial pressure and heart rate, and no signs of acute intoxication. Abdominal examination revealed discrete pain upon deep palpation and a small mass in the left iliac fossa. A plain abdominal radiograph revealed several oval structures located in the rectum and sigmoid. Fasting and a 50 g dose of activated charcoal every six hours were prescribed. After three days, the patient spontaneously evacuated 28 cocaine packs. Conclusion: Adequate clinical management and prompt identification of potential complications are of fundamental importance in dealing with body packing.

Percepções de alunos de medicina sobre marketing médico

INTRODUÇÃO: Marketing médico é um assunto controverso, principalmente no que concerne a princípios éticos. Portanto, frente à competição acirrada de mercado, é necessário o preparo profissional. Conhecer a percepção dos alunos de Medicina pode auxiliar na estruturação de alternativas de capacitação. METODOLOGIA: Inicialmente, identificaram-se crenças sobre marketing médico através de grupo focal composto por 12 alunos. Com base nesses dados, dez afirmações para avaliar atitudes foram aplicadas aos alunos de uma Faculdade de Medicina pública brasileira. RESULTADOS: Observou-se falta de clareza sobre o conceito de marketing, preocupação com princípios éticos e necessidade de marketing no mercado competitivo. Na fase de aplicação, foram obtidas 280 respostas de diversos estágios do curso. Apenas 16,8% admitiram contato com o tema. Houve clareza sobre ética em relação ao paciente, influenciada positivamente pela progressão no curso, mas houve divergência na ética entre profissionais. CONCLUSÕES: Marketing médico é uma área pouco compreendida e relegada ao currículo oculto, sendo influenciada por transposições inadequadas de métodos didáticos destinados à comunicação profissional para a população leiga. Novos métodos de ensino, como a educação tutorial, podem ser uma alternativa para lidar com essas situações.

A ironia na teoria do romance: da exigência normativo-composicional do romance em Goethe ao viver a arte em Novalis

O presente artigo busca explicitar o conceito de ironia na Teoria do romance. A explicitação do conceito de ironia se desdobrará num desenvolvimento duplo: como exigência normativo-composicional e como radicalização subjetiva que excede a normatividade. No primeiro sentido, a ironia configura subjetivamente uma totalidade na obra épica, partindo da sua fragmentação objetiva nas relações sociais modernas. Nessa acepção, a ironia se apresenta como uma manobra subjetiva a serviço da normatividade épica do romance, pois sua finalidade é harmonizar o ideal subjetivo com a objetividade histórica burguesa. Seu paradigma é representado, neste artigo, por Goethe. O outro sentido pelo qual a ironia romântica aparece é demarcado pela forma extremada da subjetividade. Esta, reconhecendo uma impossibilidade de realização de seu ideal harmônico na modernidade, porque o mundo moderno se lhe apresenta como uma efetividade oposta aos anseios subjetivos, refugia-se na própria interioridade e se distancia do mundo presente, buscando refúgio em tempos e lugares mais propícios à realização poética. Novalis é o modelo dessa ironia radicalizada. Essa forma irônica, ao contrário da "cadência irônica" de Goethe, aniquila a forma romance, uma vez que o aspecto subjetivo da pura reflexão, a lírica, se sobrepõe à objetividade histórica presente que o romance também necessariamente deve encerrar.

Chitosan: effect of a new chelating agent on the microhardness of root dentin

The effect of solutions of 0.2% chitosan, 15% EDTA and 10% citric acid on the microhardness of root dentin was evaluated comparatively in this study. Thirteen sound human maxillary central incisors were selected and decoronated at the cementoenamel junction. Ten roots were set into rapid polymerization acrylic resin and the root/resin block was fitted to the cutting machine to obtain slices from the cervical third. The first slice was discarded and the second slice was divided into four quadrants. Each quadrant was used to construct a sample, so that 4 specimens were obtained from each root slice, being one for each chelating solution to be tested: 15% EDTA, 10% citric acid, 0.2% chitosan and distilled water (control). The specimens were exposed to 50 μL of the solution for 5 min, and then washed in distilled water. A microhardness tester (Knoop hardness) with a 10 g load was used for 15 s. Data were analyzed statistically by one-way ANOVA and Tukey-Kramer test (α=0.05). The other 3 roots had the canals instrumented and irrigated at the end of the biomechanical preparation with the test solutions, and then examined by scanning electron microscopy (SEM) for qualitative analysis. All solutions reduced the microhardness of root dentin in a way that was statistically similar to each other (p>0.05) but significantly different from the control (p>0.05). The SEM micrographs showed that the three solutions removed smear layer from the middle third of the root canal. In conclusion, 0.2% chitosan, 15% EDTA and 10% citric acid showed similar effects in reducing dentin microhardness.

Time-dependent effects of chitosan on dentin structures

Complete debridement with smear layer removal are essential measures for achieving a successful outcome of root canal treatment. The aim of this study was to evaluate the effects of chitosan at different concentrations on the removal of the smear layer and on dentin structure after 3 and 5 min of application. Twelve recently extracted maxillary canine teeth were instrumented using the crown-down technique and irrigated with 1% sodium hypochlorite. The specimens were distributed according to the time and concentration of the final irrigating solution: G1: 0.1% chitosan for 3 min; G2: 0.2% chitosan for 3 min; G3: 0.37% chitosan for 3 min; G4: 0.1% chitosan for 5 min; G5: 0.2% chitosan for 5 min; G6: 0.37% chitosan for 5 min. All samples were prepared for SEM analysis. G1 exhibited removal of the smear layer, but not the smear plugs. G2 showed visible and open tubules with slight erosion of the peritubular dentin. Cleaning in G3 was similar to that in G2, however, the erosive effect was greater. There was expansion of the diameter of the tubules in G4; and in G5 and G6, there was severe erosion with deterioration of dentin surface. In conclusion, 0.2% chitosan for 3 min appeared to be efficient for removing the smear layer, causing little erosion of dentin.

Effect of sodium hypochlorite and edta irrigation, individually and in alternation, on dentin microhardness at the furcation area of mandibular molars

The aim of this study was to evaluate the effect of irrigation regimens on dentin microhardness at the furcation area of mandibular molars, using sodium hypochlorite and ethylenediaminetetraacetic acid (EDTA), individually and in alternation. The occlusal surface and the roots of 20 non-carious extracted human permanent mandibular molars were cut transversally and discarded. The tooth blocks were embedded in acrylic resin and randomly assigned to 4 groups (n=5) according to the irrigating regimens: 1% NaOCl solution, 17% EDTA solution, 1% NaOCl and 17% EDTA and distilled water (control). Knoop microhardness of dentin at the furcation area was evaluated. Data were analyzed using one-way ANOVA and Tukey's multiple comparison tests (α=0.05). The results of this study indicated that all irrigation solutions, except for distilled water (control), decreased dentin microhardness. EDTA did not show a significant difference with NaOCl/EDTA (p>0.05), but showed a significant difference with NaOCl (p<0.01). EDTA and NaOCl/EDTA showed a maximum decrease in microhardness. The 17% EDTA solution, either alone or in combination with 1% NaOCl reduced significantly dentin microhardness at the furcation area of mandibular molars.

Desfechos intra-hospitalares e preditores de mortalidade no infarto agudo do miocárdio com choque cardiogênico tratados por angioplastia primária: dados do registro InCor

INTRODUÇÃO: O choque cardiogênico é a maior causa de morte em pacientes com infarto agudo do miocárdio com supradesnivelamento do segmento de ST (IAMCSST). O presente estudo avaliou pacientes com IAMCSST e choque cardiogênico submetidos a intervenção coronária percutânea primária com o objetivo de estabelecer seu perfil e os preditores de mortalidade hospitalar. MÉTODOS: Registro unicêntrico, incluindo 100 pacientes avaliados no período de 2001 a 2009 quanto a características clínicas, angiográficas e do procedimento, e a desfechos intra-hospitalares. Por análise multivariada foram determinados preditores independentes da mortalidade hospitalar. RESULTADOS: Com relação às características clínicas, foi observada alta prevalência de fatores de risco, sendo a taxa de sucesso angiográfico de 92%, apesar da complexidade das lesões (83,1% do tipo B2/C). A artéria mais acometida foi a descendente anterior (45%), tendo o padrão multiarterial ocorrido em 73% dos casos. A taxa de mortalidade foi de 45%, sendo seus preditores independentes o padrão multiarterial [odds ratio (OR) 2,62; intervalo de confiança de 95% (IC 95%) 1,16-5,90] e o fluxo coronário TIMI < 3 ao final do procedimento (OR 2,11, IC 95% 1,48-3,02). CONCLUSÕES: Os pacientes com IAMCSST complicado por choque cardiogênico apresentaram características clínicas e angiográficas de alto risco e, apesar do alto sucesso angiográfico do procedimento, altas taxas de mortalidade. Foram preditores independentes de mortalidade o padrão multiarterial e fluxo TIMI < 3 ao final do procedimento.

The renin–angiotensin system plays a major role in voiding dysfunction of ovariectomized rats

Aims: The renin–angiotensin system (RAS) plays a major role in cardiovascular diseases in postmenopausal women, but little is known about its importance to lower urinary tract symptoms. In this study we have used the model of ovariectomized (OVX) estrogen-deficient rats to investigate the role of RAS in functional and molecular alterations in the urethra and bladder. Main methods: Responses to contractile and relaxant agents in isolated urethra and bladder, as well as cystometry were evaluated in 4-month OVX Sprague–Dawley rats. Angiotensin-converting enzyme activity and Western blotting for AT1/AT2 receptors were examined. Key findings: Cystometric evaluations in OVX rats showed increases in basal pressure, capacity and micturition frequency, as well as decreased voiding pressure. Angiotensin II and phenylephrine produced greater urethral contractions in OVX compared with Sham group. Carbachol-induced bladder contractions were significantly reduced in OVX group. Relaxations of urethra and bladder to sodium nitroprusside and BAY 41-2272 were unaffected by OVX. Angiotensin-converting enzyme activity was 2.6-fold greater (p < 0.05) in urethral tissue of OVX group,whereas enzyme activity in plasma and bladder remained unchanged. Expressions of AT1 and AT2 receptors in the urethra were markedly higher in OVX group. In bladder, AT1 receptors were not detected, whereas AT2 receptor expression was unchanged between groups. 17β-Estradiol replacement (0.1 mg/kg, weekly) or losartan (30 mg/kg/day) largely attenuated most of the alterations seen in OVX group. Significance: Prolonged estrogen deprivation leads to voiding dysfunction and urethral hypercontractility that are associated with increased ACE activity and up-regulation of angiotensin AT1/AT2 receptor in the urethral tissue.

Juden in Rio Grande do Sul

Antonio Salles