Proton magnetic resonance spectroscopy of the frontal lobe in schizophrenics: a critical review of the methodology

Schizophrenic patients undergoing proton magnetic resonance spectroscopy show alterations in N-acetyl aspartate levels in several brain regions, indicating neuronal dysfunction. The present review focuses on the main proton magnetic resonance spectroscopy studies in the frontal lobe of schizophrenics. A MEDLINE search, from 1991 to March 2004, was carried out using the key-words spectroscopy and schizophrenia and proton and frontal. In addition, articles cited in the reference list of the studies obtained through MEDLINE were included. As a result, 27 articles were selected. The results were inconsistent, 19 papers reporting changes in the N-acetyl aspartate levels, while 8 reported no change. Methodological analysis led to the conclusion that the discrepancy may be due the following factors: (i) number of participants; (ii) variation in the clinical and demographic characteristics of the groups; (iii) little standardization of the acquisition parameters of spectroscopy. Overall, studies that fulfill strict methodological criteria show N-acetyl aspartate decrease in the frontal lobe of male schizophrenics.

Cyperaceae of Tropical America: some new or critical species III

Discussed are the taxonomy of the Scleria arundinacea-latifoliacomplex, S. mitis, and S. myricocarpa, all controversial and widespread taxa in tropical America. Scleria cerradicola is described as new in the section Hymenolytrum and a range extension of a rare species, Scleria neogranatensis, is noted.

NOMENCLATURAL AND CRITICAL NOTES ON SOME BRAZILIAN SPECIES OF Paspalum (POACEAE: PANICEAE)

A critical analysis of the type collections of 39 species names of Paspalum L. (Poaceae: Paniceae) from Brazil described by Swallen is presented along with comments based on more recent gatherings of the species. Eighteen new synonyms are proposed.

Critical aortic stenosis in the neonate. Clinical assessment and surgical outcome in 18 patients

OBJECTIVE - To assess neonates with aortic stenosis with early decompensation operated upon. (LCO) (CHF). METHODS - A and retrospective study analyzing 6 neonates with LCO, group I (GI), and 12 neonates with CHF, group II (GII). Clinical radiographic, electrocardiographic and echocardiographic findings also provided comparative bases for the study, as did surgical and evolutional findings. RESULTS - The mean ages at hospitalization and surgery (p = 0.0031) were 14.3 and 14.8 days in GI and 35.4 and 42.8 days in GII, respectively. Cardiac murmurs were more intense in GII (p = 0.0220). The aortic ring was smaller in GI (8.0 ± 2.5mm) as compared to GII (11.4±1.4mm) (p = 0.2882). Ventricular function was reduced to 18±5.5% and 33.3±7.6% in GI and GII, respectively (p = 0.0162). Aortic atresia, however, was present only in 2 neonates in GI. Five of 6 patients in GI died but all patients in GII survived (p=0.0007). In the latter group, 84.6% of the patients were in functional class I (FC-I) in the long-term follow-up, with moderate residual lesions in 6 neonates, discrete residual lesions in 4, and reoperation in 2. CONCLUSION - Aortic stenosis is a severe anomaly of the neonate, whose immediate evolution depends on the pre-operative anatomic and functional findings, and the late evolution essentially depends on the anatomic features of the valve.

Software livre e de código aberto para avaliação de imagens de angiotomografia de coronárias

FUNDAMENTO: A estandardização do padrão de imagens utilizada dentro da medicina foi realizada em 1993 por meio do padrão DICOM (Digital Imaging and Communications in Medicine). Diversos exames utilizam esse padrão e cada vez mais são necessários softwares capazes de manipular esse tipo de imagem, porém esses softwares geralmente não têm o formato livre e de código aberto, e isso dificulta o seu ajuste para os mais diferentes interesses. OBJETIVO: Desenvolver e validar um software livre e de código aberto capaz de manipular imagens DICOM de exames de angiotomografia de coronárias. MÉTODOS: Desenvolvemos e testamos o software intitulado ImageLab na avaliação de 100 exames selecionados de forma randômica por meio de um banco de dados. Foram realizadas 600 análises divididas por dois observadores utilizando o ImageLab e um outro software comercializado junto a aparelhos de tomografia computadorizada Philips Brilliance, na avaliação da presença de lesões e placas coronarianas nos territórios do Tronco da Coronária Esquerda (TCE) e na Artéria Descendente Anterior (ADA). Para avaliar as concordâncias intraobservador, interobservadores e intersoftware, utilizamos concordância simples e estatística Kappa. RESULTADOS: As concordâncias observadas entre os softwares foram em geral classificadas como substancial ou quase perfeitas na maioria das comparações. CONCLUSÃO: O software ImageLab concordou com o software Philips na avaliação de exames de angiotomografia de coronárias especialmente em pacientes sem lesões, com lesões inferiores a 50% no TCE e inferiores a 70% na ADA. A concordância para lesão >70% na ADA foi menor, porém isso também é observado quando se utiliza o padrão de referência anatômico.

A Critical Review on Chagas Disease Chemotherapy

In this "Critical Review" we made a historical introduction of drugs assayed against Chagas disease beginning in 1912 with the works of Mayer and Rocha Lima up to the experimental use of nitrofurazone. In the beginning of the 70s, nifurtimox and benznidazole were introduced for clinical treatment, but results showed a great variability and there is still a controversy about their use for chronic cases. After the introduction of these nitroheterocycles only a few compounds were assayed in chagasic patients. The great advances in vector control in the South Cone countries, and the demonstration of parasite in chronic patients indicated the urgency to discuss the etiologic treatment during this phase, reinforcing the need to find drugs with more efficacy and less toxicity. We also review potential targets in the parasite and present a survey about new classes of synthetic and natural compounds studied after 1992/1993, with which we intend to give to the reader a general view about experimental studies in the area of the chemotherapy of Chagas disease, complementing the previous papers of Brener (1979) and De Castro (1993).

Failure of neutrophil migration toward infectious focus in severe sepsis: a critical event for the outcome of this syndrome

Sepsis is a systemic inflammatory response commonly caused by bacterial infection. We demonstrated that the outcome of sepsis induced by cecal ligation and puncture (CLP) correlates with the severity of the neutrophil migration failure towards infectious focus. Failure appears to be due to a decrease in the rolling and adhesion of neutrophil to endothelium cells. It seems that neutrophil migration impairment is mediated by the circulating inflammatory cytokines, such as TNF-alpha and IL-8, which induce the nitric oxide (NO) production systemically. It is supported by the fact that intravenous administration of these cytokines reduces the neutrophil migration induced by different inflammatory stimuli, and in severe sepsis the circulating concentrations of the cytokines and chemokines are significantly increased. Moreover, the neutrophil migration failure and the reduction in the rolling/adhesion were not observed in iNOS-/- mice and, aminoguanidine prevented this event. We also demonstrated that the failure of neutrophil migration is a Toll-4 receptor (TLR4) dependent mechanism, since it was not observed in TLR4 deficient mice. Furthermore, it was also observed that circulating neutrophils obtained from septic patients present failure of neutrophil chemotaxis toward fMLP, IL-8, and LTB4 and an increased in sera concentrations of NO3 and cytokines. In conclusion, we demonstrated that, in sepsis, failure of neutrophil migration is critical for the outcome and that NO is involved in the process.

The second internal transcribed spacer of nuclear ribosomal DNA as a tool for Latin American anopheline taxonomy: a critical review

Among the molecular markers commonly used for mosquito taxonomy, the internal transcribed spacer 2 (ITS2) of the ribosomal DNA is useful for distinguishing among closely-related species. Here we review 178 GenBank accession numbers matching ITS2 sequences of Latin American anophelines. Among those, we found 105 unique sequences corresponding to 35 species. Overall the ITS2 sequences distinguish anopheline species, however, information on intraspecific and geographic variations is scarce. Intraspecific variations ranged from 0.2% to 19% and our analysis indicates that misidentification and/or sequencing errors could be responsible for some of the high values of divergence. Research in Latin American malaria vector taxonomy profited from molecular data provided by single or few field capture mosquitoes. However we propose that caution should be taken and minimum requirements considered in the design of additional studies. Future studies in this field should consider that: (1) voucher specimens, assigned to the DNA sequences, need to be deposited in collections, (2) intraspecific variations should be thoroughly evaluated, (3) ITS2 and other molecular markers, considered as a group, will provide more reliable information, (4) biological data about vector populations are missing and should be prioritized, (5) the molecular markers are most powerful when coupled with traditional taxonomic tools.

Schistosome vaccines: a critical appraisal

An effective schistosome vaccine is a desirable control tool but progress towards that goal has been slow. Protective immunity has been difficult to demonstrate in humans, particularly children, so no routes to a vaccine have emerged from that source. The concept of concomitant immunity appeared to offer a paradigm for a vaccine operating against incoming larvae in the skin but did not yield the expected dividends. The mining of crude parasite extracts, the use of monoclonal antibodies and protein selection based on immunogenicity produced a panel of vaccine candidates, mostly of cytoplasmic origin. However, none of these performed well in independent rodent trials, but glutathione-S-transferease from Schistosoma haematobium is currently undergoing clinical trials as an anti-fecundity vaccine. The sequencing of the S. mansoni transcriptome and genome and the development of proteomic and microarray technologies has dramatically improved the possibilities for identifying novel vaccine candidates, particularly proteins secreted from or exposed at the surface of schistosomula and adult worms. These discoveries are leading to a new round of protein expression and protection experiments that will enable us to evaluate systematically all the major targets available for immune intervention. Only then will we know if schistosomes have an Achilles' heel.