Rapid diagnosis in pediatric infectious diseases: The past, the present and the future

The focus of rapid diagnosis of infectious diseases of children in the last decade has shifted from variations of the conventional laboratory techniques of antigen detection, microscopy and culture to that of molecular diagnosis of infectious agents. Pediatricians will need to be able to interpret the use, limitations and results of molecular diagnostic techniques as they are increasingly integrated into routine clinical microbiology laboratory protocols. PCR is the best known and most successfully implemented diagnostic molecular technology to date. It can detect specific infectious agents and determine their virulence and antimicrobial genotypes with greater speed, sensitivity and specificity than conventional microbiology methods. Inherent technical limitations of PCR are present, although they are reduced in laboratories that follow suitable validation and quality control procedures. Variations of PCR together with advances in nucleic acid amplification technology have broadened its diagnostic capabilities in clinical infectious disease to now rival and even surpass traditional methods in some situations. Automation of all components of PCR is now possible. The completion of the genome sequencing projects for significant microbial pathogens, in combination with PCR and DNA chip technology, will revolutionize the diagnosis and management of infectious diseases.

Estudo de casos de pacientes portadores de onicomicose tratados com laser Nd : YAG 1.064 nm

Onicomicose é a doença ungueal mais frequente, com prevalência estimada entre 2 e 8% da população. As estratégias de tratamentos atuais incluem uso de antifúngicos tópicos e orais, ambos geralmente com baixos índices de cura. Os objetivos deste estudo foram avaliar a resposta terapêutica ao laser Nd:YAG 1.064 nm no tratamento da onicomicose, bem como o método de avaliação clínica dessa terapia e os possíveis efeitos colaterais de seu uso. Foram revisados prontuários de 20 pacientes submetidos à laserterapia. Ao todo, 34 unhas afetadas foram avaliadas de acordo com o Índice de Severidade de Onicomicose (ISO). Esse índice analisa a área de envolvimento da unha, a proximidade da doença com a matriz ungueal, a ocorrência de dermatofitoma e a presença de hiperqueratose subungueal > 2 mm, gerando uma pontuação que classifica a onicomicose como leve, moderada ou grave. A determinação do ISO foi realizada antes do tratamento e após um período de acompanhamento, em média, de oito meses. A comparação entre o ISO Inicial e o ISO Final nas 34 unhas submetidas à laserterapia mostrou diferença significativa, porém, com baixa associação entre essas variáveis. Com relação à área de envolvimento e à pontuação numérica referente ao ISO, houve, no geral, uma redução dessas medidas. Esses dados apontam para uma tendência à melhora da onicomicose por meio do tratamento com o laser Nd:YAG 1.064 nm. O ISO permitiu uma análise clínica adequada da resposta à laserterapia. Os efeitos colaterais locais apresentados durante a aplicação do laser não causaram desconforto acentuado na maioria dos pacientes, demonstrando que o procedimento é bem tolerado.

Prova de esforço e factores de risco cardiovascular: um estudo piloto

As doenças cardiovasculares (DCV’s) são a maior causa de mortalidade e morbilidade em Portugal. O seu elevado impacto passa pelo desconhecimento, sub-diagnóstico, elevada prevalência e descontrolo dos seus principais factores de risco (clássicos e novos marcadores bioquímicos). Para o diagnóstico de uma das vertentes da doença cardiovascular, a doença cardíaca isquémica, a prova de esforço (PE) é o exame não invasivo, de baixo custo, com reduzida taxa de complicações e de fácil execução, mais usado na clínica. O objectivo deste estudo é averiguar se existe relação entre a prova de esforço, os factores de risco cardiovascular (FR’s) e alguns dos seus marcadores bioquímicos. Com vista a alcançar objectivo realizou-se um estudo prospectivo, longitudinal e descritivo, na Esferasaúde (Maia), entre Janeiro e Maio de 2011. Foram recolhidos dados, por inquérito, referentes a: biografia, antropometria, FR’s, medicação, PE e análises clínicas. Tendo sido incluídos todos os indivíduos (idade ≥ 18 anos) que tenham realizado prova de esforço e análises na unidade citada e com diferença temporal máxima de 2 meses, pelo método de amostragem dirigida e intencional. A dimensão amostral situou-se nos 30 elementos, sendo que 19 eram do género masculino. A média de idade foi 49,43±15,39 anos. Estimou-se a prevalência de FR’s e de indivíduos com valores dos marcadores bioquímicos anormais. Dois dos indivíduos apresentavam história de DCV’s e três deles PE positiva. Foram efectuadas diversas tentativas de associação entre as variáveis integradas no estudo - DCV e FR’s; PE e FR’s; PE e marcadores bioquímicos; capacidade de esforço e FR’s, género e resultado PE. Nenhuma relação se revelou significativa, com excepção para dois casos: relação entre as DCV’s e o aparecimento de alterações na PE (p = 0,002) e associação entre PE e colesterol HDL (p=0,040). Para α de 5%. Conclui-se que não existe relação aparente entre a prova de esforço, a existência de doença cardiovascular, os seus factores de risco e marcadores bioquímicos.

Electroanalysis of urinary L-dopa using tyrosinase immobilized on gold nanoelectrode ensembles

The performance of an amperometric biosensor constructed by associating tyrosinase (Tyr) enzyme with the advantages of a 3D gold nanoelectrode ensemble (GNEE) is evaluated in a flow-injection analysis (FIA) system for the analysis of l-dopa. GNEEs were fabricated by electroless deposition of the metal within the pores of polycarbonate track-etched membranes. A simple solvent etching procedure based on the solubility of polycarbonate membranes is adopted for the fabrication of the 3D GNEE. Afterward, enzyme was immobilized onto preformed self-assembled monolayers of cysteamine on the 3D GNEEs (GNEE-Tyr) via cross-linking with glutaraldehyde. The experimental conditions of the FIA system, such as the detection potential (−0.200 V vs. Ag/AgCl) and flow rates (1.0 mL min−1) were optimized. Analytical responses for l-dopa were obtained in a wide concentration range between 1 × 10−8 mol L−1 and 1 × 10−2 mol L−1. The limit of quantification was found to be 1 × 10−8 mol L−1 with a resultant % RSD of 7.23% (n = 5). The limit of detection was found to be 1 × 10−9 mol L−1 (S/N = 3). The common interfering compounds, namely glucose (10 mmol L−1), ascorbic acid (10 mmol L−1), and urea (10 mmol L−1), were studied. The recovery of l-dopa (1 × 10−7 mol L−1) from spiked urine samples was found to be 96%. Therefore, the developed method is adequate to be applied in the clinical analysis.

Retreatment in leprosy: a case-control study

OBJECTIVE: To assess risk factors for retreatment of leprosy patients. METHODS: A case-control study with patients from two reference care units in Recife, northeastern Brazil, in 2003. The case group included retreated patients (N=155) and the control group comprised those patients who were not retreated (N=155) matched by year of diagnosis and health care unit. Univariate and multivariate analyses were conducted to test the associations and odds ratios and related 95% confidence intervals were estimated. RESULTS: The following factors were found to be significantly associated (p<0.05) with retreatment: occurrence of adverse immunological reactions after treatment completion (OR=2.3; 95% CI=1.18;4.83), final bacterial index > 1 (OR=6.43; 95% CI=1.67;24.74), therapeutic regimen consisting of sulfone monotherapy (OR=10; 95% CI=0.01;0.78) and reports of household contacts (OR=2.2; 95% CI=0.24;0.85). CONCLUSIONS: The study findings reinforce that the use of dapsone monotherapy should be discontinued, and highlight the need for epidemiological monitoring of specific groups of leprosy patients after treatment completion through periodical clinical and laboratory evaluation. Further studies to explore the association between final bacterial index and retreatment are strongly recommended.

O impacto da formação contínua no desenvolvimento pessoal e profissional dos técnicos de Análises Clínicas e Saúde Pública

Mestrado em Intervenção Sócio-Organizaional na Saúde - Ramo de especialização: Intervenção Comunitária

Human disease in ribeira valley, brazil caused by caraparu, a group c arbovirus - Report of a case

The clinical and laboratory data of a disease in a resident of Ribeira Valley, São Paulo State, southeastern Brazil, caused by an agent close or identical to Caraparu, a Group C arbovirus, was described. Although there is evidence of an intensive circulation of several arboviruses in the area, no diagnosis of human disease by these agents has been made, except the encephalitis cases caused by Rocio virus during an epidemic in 1975-1977. An antigenic difference between Caraparu strains isolated in São Paulo and in Pará States and a close antigenic relationship between Caraparu strain from São Paulo and Bruconha virus were suggested by the serological tests.

Cytomegalovirus and other herpesviruses infections in heart and bone marrow transplant recipients

From January 1988 to January 1989 all the heart transplant and bone marrow recipients at the Instituto do Coração of the Hospital das Clínicas of the University of São Paulo Medical School were studied for the incidence and morbidity associated with herpesviruses infections after transplantation. Five bone marrow and 5 heart transplant recipients were followed for a mean of 4.2 months post-transplantation. All the patients were seropositive for cytomegalovirus (CMV) before admission and 80% experienced one or more recurrences during the observation period. Of the 12 episodes of CMV infection, that were identified in this study, 83% were accompanied by clinical or laboratory abnormalities. However, there was only one case of severe disease. The overall incidence of infection for herpes simplex (HSV) was 50%. Although most of HSV reactivations were oral or genital, one case of HSV hepatitis occurred. One of the 6 episodes of HSV infections that were treated with acyclovir showed an unsatisfactory response and was successfully managed with ganciclovir. All the individuals had anti-varicella zoster virus antibodies, but none of them developed infection. The study emphasizes the importance of active diagnostic surveillance of herpesvirus infections in transplant patients. Both CMV and HSV reactivations showed high incidence and important morbidity and thus, deserve prophylactic therapy.

Renal involvement in prolonged salmonella bacteremia: the role of schistosomal glomerulopathy

Renal involvement has been well documented in patients with hepatosplenic schistosomiasis and in patients with prolonged salmonella bacteremia (PSB). Whether there is a specific renal lesion related to PSB or the chronic bacterial infection aggravates a pre-existing schistosomal glomerulopathy has been a matter of controversy. To analyze the clinical manifestations and histopathological findings of the renal involvement, 8 patients with hepatosplenic schistosomiasis and PSB (group I) were compared with 8 patients with schistosomal glomerulopathy (group II) matched by sex and glomerular disease. The mean age in group I was 17.7 years. All patients presented with hematuria, in 4 cases associated with non-nephrotic proteinuria. In group II the mean age was 23 years; nephrotic syndrome was the clinical presentation in 7 of the 8 patients in the group. All patients in group I experienced remission of the clinical and laboratory abnormalities as the salmonella infection was cured; in group II the patients had persistent, steroid-resistant, nephrotic syndrome. On histological examination, no difference was noted between the two groups, except for pronounced glomerular hypercellularity and interstitial mononuclear cell infiltration in group I. These observations strongly suggest that PSB exacerbates a pre-existing sub-clinical schistosomal glomerulopathy by the addition of active lesions directly related to the prolonged bacteremia

Proof of Concept of the Electrochemical Sensing of 3-Iodothyronamine (T1AM) and Thyronamine (T0AM)

Recent studies have shown that, besides the well-recognized T3 and T4 hormones, there are other relevant thyroid hormones circulating in the human body. In particular, this is the case for 3-iodothyronamine (T1AM) and thyronamine (T0AM). One of the reasons for the lack of studies showing their precise importance is the absence of analytical methodologies available. Herein, for the first time, T1AM and T0AM are electrochemically characterized. T0AM was sensed by means of a glassy carbon electrode; furthermore, T1AM was sensed both with a graphitic surface (oxidatively) as well as with mercury (reductively). For both compounds, after oxidation, it was possible to observe the reversible redox reaction concerning the benzoquinone/hydroquinone couple, thus increasing the specificity of the electroanalysis. Therefore, this work provides the basis for an ‘at-point-of-use’ electrochemical strip test for T1AM and T0AM.

Dot-enzyme-linked immunosorbent assay (Dot-ELISA) for detection of pneumococcal polysaccharide antigens in pleural fluid effusion samples.: Comparison with bacterial culture, counterimmunoelectrophoresis and latex agglutination

A dot-enzyme-linked immunosorbent assay (Dot-ELISA) for pneumococcal antigen detection was standardized in view of the need for a rapid and accurate immunodiagnosis of acute pneumococcal pneumonia. A total of 442 pleural fluid effusion samples (PFES) from children with clinical and laboratory diagnoses of acute bacterial pneumonia, plus 38 control PFES from tuberculosis patients and 20 negative control serum samples from healthy children were evaluated by Dot-ELISA. The samples were previously treated with 0.1 M EDTA pH 7.5 at 90°C for 10 min and dotted on nitrocellulose membrane. Pneumococcal omniserum diluted at 1:200 was employed in this assay for antigen detection. When compared with standard bacterial culture, counterimmunoelectrophoresis and latex agglutination techniques, the Dot-ELISA results showed relative indices of 0.940 to sensitivity, 0.830 to specificity and 0.760 to agreement. Pneumococcal omniserum proved to be an optimal polyvalent antiserum for the detection of pneumococcal antigen by Dot-ELISA. Dot-ELISA proved to be a practical alternative technique for the diagnosis of pneumococcal pneumonia.

The malarial impact on the nutritional status of Amazonian adult subjects

The anthropometric (body weight, height, upper arm circumference, triceps and subescapular skinfolds; Quetelet index and arm muscle circunference) and blood biochemistry (proteins and lipids) parameters were evaluated in 93 males and 27 females, 17-72 years old voluntaries living in the malarial endemic area of Humaita city (southwest Amazon). According to their malarial history they were assembled in four different groups: G1-controls without malarial history (n:30); G2 - controls with malarial history but without actual manifestation of the disease (n:40); G3 - patients with Plasmodium vivax (n:19) and G4 - patients with Plasmodium falciparum (n:31). The malarial status was stablished by clinical and laboratory findings. The overall data of anthropometry and blood biochemistry discriminated the groups differently. The anthropometric data were low sensitive and contrasted only the two extremes (G1>G4) whereas the biochemistry differentiated two big groups, the healthy (G1+G2) and the patients (G3+G4). The nutritional status of the P. falciparum patients was highly depressed for most of the studied indices but none was sensitive enough to differentiate this group from the P. vivax group (G3). On the other hand the two healthy groups could be differentiated through the levels of ceruloplasmin (G1G2). Thus it seems that the malaria-malnourishment state exists and the results could be framed either as a consequence of nutrient sink and/or the infection stress both motivated by the parasite.

Frequency of dermatophytes in the metropolitan area of Porto Alegre, RS, Brazil

In order to evaluate the distribution of dermatophytes in Porto Alegre, the capital of the state of Rio Grande do Sul, Brazil, they were isolated from the skin, hairs and nails samples and retrospectively analyzed from June 1981 to June 1995, in two different institutions in the city of Porto Alegre: (i) the Serviço de Micologia do Instituto de Pesquisas Biológicas Jandyr Maya Faillace, da Secretaria de Saúde e Meio Ambiente do Rio Grande do Sul which attends the low income population (low and middle classes) and, (ii) Laboratório Weinmann, a clinical pathology laboratory which attends predominantly the higher income population (middle and upper classes), both which attend in the metropolitan area of Porto Alegre. The dermatophyte predominance of Trichophyton rubrum was confirmed (55.33%) followed by T. mentagrophytes (21.46%). The data obtained were compared with the existing prevalence data which were collected in the interior of the state over a period of 32 years (1960-1992). T. verrucosum, T. simii, Microsporum persicolor, T. schöenleinii, M. nanum and M. cookei were isolated in the interior and have not been found in the capital so far. On the other side, T. violaceum was, isolated in the capital and has not been found in the interior so far.

Gallium-67 imaging in a patient with paracoccidioidomycosis: a case report

A 26 year-old female was admitted with abdominal pain, fever and weight loss. The clinical and laboratory investigations led to the diagnosis of paracoccidioidomycosis. Gallium-67 whole body images correlated well with the clinical course of the disease and with the patient's prognosis.

Evaluation of hemostasis disorders and anticardiolipin antibody in patients with severe leptospirosis

A prospective study was designed to evaluate disorders of hemostasis and levels of anticardiolipin antibodies (ACL) in 30 patients with severe leptospirosis and acute renal failure (ARF) (ARF was defined as serum creatinine > or = 1.5 mg/dL). The patients had been admitted to the Walter Cantídio University Hospital, São José Infectious Diseases Hospital and General Hospital of Fortaleza, Ceará, from August 1999 to July 2001. They all were male, with a mean age of 32 ± 14 years and with clinical and laboratory diagnoses of ARF leptospirosis. The time elapsed between onset of symptoms and the first hemorrhagic manifestation was 9 ± 4 days. Bleeding was observed in 86% of the patients. Laboratory tests showed significantly high levels of urea (181 ±95 mg/dl), fibrinogen, (515 ± 220 mg/dl), prothrombin time (13.3 ± 0.9 seconds) and low platelet counts (69 ± 65x10³/mm³) on admission. There was no elevation in activated partial thromboplastin time or thrombin time. Levels of IgM and IgG ACL concentrations were significantly increased (p < 0.05) in leptospirosis patients when compared to control patients (28.5 ± 32.4 vs. 11.5 ± 7.9MPL U/ml and 36.7 ± 36.1 vs. 6.5 ± 2.5 GPL U/ml), respectively. Vasculitis, thrombocytopenia and uremia should be considered important factors for the pathogenesis of hemorrhagic disturbances and the main cause of death in severe leptospirosis.