Performance evaluate of different chemometrics formalisms used for prostate cancer diagnosis by NMR-based metabolomics.

INTRODUCTION: In general, two characteristics are ever present in NMR-based metabolomics studies: (1) they are assays aiming to classify the samples in different groups, and (2) the number of samples is smaller than the feature (chemical shift) number. It is also common to observe imbalanced datasets due to the sampling method and/or inclusion criteria. These situations can cause overfitting. However, appropriate feature selection and classification methods can be useful to solve this issue. OBJECTIVES: Investigate the performance of metabolomics models built from the association between feature selectors, the absence of feature selection, and classification algorithms, as well as use the best performance model as an NMR-based metabolomic method for prostate cancer diagnosis. METHODS: We evaluated the performance of NMR-based metabolomics models for prostate cancer diagnosis using seven feature selectors and five classification formalisms. We also obtained metabolomics models without feature selection. In this study, thirty-eight volunteers with a positive diagnosis of prostate cancer and twenty-three healthy volunteers were enrolled. RESULTS: Thirty-eight models obtained were evaluated using AUROC, accuracy, sensitivity, specificity, and kappa's index values. The best result was obtained when Genetic Algorithm was used with Linear Discriminant Analysis with 0.92 sensitivity, 0.83 specificity, and 0.88 accuracy. CONCLUSION: The results show that the pick of a proper feature selection method and classification model, and a resampling method can avoid overfitting in a small metabolomic dataset. Furthermore, this approach would decrease the number of biopsies and optimize patient follow-up. 1H NMR-based metabolomics promises to be a non-invasive tool in prostate cancer diagnosis.

Prediction of semen analysis parameter improvement after varicocoelectomy using 1 H NMR-based metabonomics assays.

BACKGROUND: Varicocoele is the most common correctable cause of male infertility; however, predicting varicocoelectomy outcomes is difficult. "Omics" techniques have been increasingly used to develop new diagnostic and prognostics tools for several male infertility causes, and could be applied to study varicocoele. OBJECTIVES: The objective is to create metabolomics models capable of segregating men who improved semen analysis (SA) parameters or achieved natural pregnancy after microsurgical varicocoelectomy (MV) from those who did not, using hydrogen-1 nuclear magnetic resonance (1 H NMR) spectra of seminal plasma of pre-operative samples. MATERIAL AND METHODS: We recruited 29 infertile men with palpable varicocoele. 1 H NMR spectra of seminal plasma were obtained from pre-operative samples and used to create metabonomics models. Improvement was defined as an increase in the total motile progressive sperm count (TMC) of the post-operative SA when compared to the baseline, and pregnancy was assessed for 24 months after MV. RESULTS: Using linear discriminant analysis (LDA), we created a model that discriminated the men who improved SA from those who did not with accuracy of 93.1%. Another model segregated men who achieved natural pregnancy from men who did not. We identified seven metabolites that were important for group segregation: caprylate, isoleucine, N-acetyltyrosine, carnitine, N-acetylcarnitine, creatine, and threonine. DISCUSSION: We described the use of metabonomics model to predict with high accuracy the outcomes of MV in infertile men with varicocoele. The most important metabolites for group segregation are involved in energy metabolism and oxidative stress response, highlighting the pivotal role of these mechanisms in the pathophysiology of varicocoele. CONCLUSIONS: 1 H NMR spectroscopy of seminal plasma can be used in conjunction with multivariate statistical tools to create metabonomics models useful to segregate men with varicocoele based on the reproductive outcomes of MV. These models may help counseling infertile men with varicocoele regarding their prognosis after surgery.

Assessment of periportal fibrosis in Schistosomiasis mansoni patients by proton nuclear magnetic resonance-based metabonomics models.

BACKGROUND: The evaluation of periportal fibrosis (PPF) is essential for a prognostic assessment of patients with Schistosomiasis mansoni. The WHO Niamey Protocol defines patterns of fibrosis from abdominal ultrasonography, 1H-nuclear magnetic resonance (NMR)-based metabonomics has been employed to assess liver fibrosis in some diseases. AIM: To build 1H-NMR-based metabonomics models (MM) to discriminate mild from significant periportal PPF and identify differences in the metabolite profiles. METHODS: A prospective cross-sectional study was performed on schistosomiasis patients at a University Hospital in Northeastern Brazil. We evaluated 41 serum samples from 10 patients with mild PPF (C Niamey pattern) and 31 patients with significant PPF (D/E/F Niamey patterns). MM were built using partial least squares-discriminant analysis (PLS-DA) and orthogonal projections to latent structures discriminant analysis (OPLS-DA) formalisms. RESULTS: PLS-DA and OPLS-DA resulted in discrimination between mild and significant PPF groups with R2 and Q2 values of 0.80 and 0.38 and 0.72 and 0.42 for each model, respectively. The OPLS-DA model presented accuracy, sensitivity, and specificity values of 92.7%, 90.3%, and 100% to discriminate significant PPF. The metabolites identified as responsible by discrimination were: N-acetylglucosamines, alanine, glycolaldehyde, carbohydrates, and valine. CONCLUSION: MMs discriminated mild from significant PPF patterns in patients with Schistosomiasis mansoni through identification of differences in serum metabolites profiles.

Evaluation of Chlorhexidine Concentration on the Skin After Preoperative Surgical Site Preparation in Breast Surgery-A Randomized Controlled Trial.

BACKGROUND: Although there is a rationale supporting that preoperative showering with 2% or 4% chlorhexidine gluconate (CHG) would decrease skin bacterial colonization, there is no consensus that this practice reduces the risk of surgical site infection (SSI). OBJECTIVES: Analyze the skin concentration of CHG after preoperative showering associated with the traditional skin preparation with CHG 4% for breast surgery. METHODS: Randomized controlled trial that included 45 patients, all candidates for augmentation mammaplasty, allocated into three groups (A: no preoperative showering; B: one preoperative showering; C: two preoperative showering with CHG 4%) in a 1:1:1 ratio. Skin swabs collection was performed right before the surgical incision. The samples were, then, sent to spectrophotometry in order to determine the skin concentration of CHG at the beginning of surgery. RESULTS: The age ranged from 18 to 61 years, with a mean of 37 years old. Group C had the lowest median concentration (0.057) followed by group B (0.060) and group A (0.072), however, with no statistical significance. The areola was the place with the lowest median concentration level (0.045), followed by the axilla (0.061) and the inframammary fold (IMF) (0.069). Still, when comparing the distribution of the sites, a statistically significant difference was found only between the axilla and the areola (p = 0.022). CONCLUSION: Preoperative showering with CHG 4% did not increase the concentration of this agent on the skin surface right before the surgical incision. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

1H NMR-based metabonomics for infertility diagnosis in men with varicocele.

PURPOSE: "Omics" techniques have been used to understand and to identify biomarkers of male infertility. We report on the first metabonomics models created to diagnose varicocele and infertility among men with varicocele. METHODS: We recruited 35 infertile men with varicocele (VI group), 21 fertile men with varicocele (VF group) and 24 fertile men without varicocele (C group). All men underwent standard semen analysis, scrotal duplex ultrasonography, and sexual hormone level measurement. Hydrogen-1 nuclear magnetic resonance (1H NMR) spectra of seminal plasma were used to create metabonomics models to discriminate between men with and without varicocele, and between fertile and infertile men with varicocele. RESULTS: Using the statistical formalisms partial least square discriminants analysis and genetic algorithm-based linear discriminant analysis (GA-LDA), we created two models that discriminated the three groups from each other with accuracy of 92.17%. We also created metabonomics models using orthogonal partial least square discriminants analysis and GA-LDA that discriminated VF group from VI group, with an accuracy of 94.64% and 100% respectively. We identified 19 metabolites that were important in group segregation: caprate, 2-hydroxy-3-methylvalerate, leucine, valine, 3-hydroxybutyrate, lactate, alanine, 4-aminobutyrate, isoleucine, citrate, methanol, glucose, glycosides, glycerol-3-phosphocoline, n-acetyltyrosine, glutamine, tyrosine, arginine, and uridine. CONCLUSIONS: 1HNMR-based metabonomics of seminal plasma can be used to create metabonomics models to discriminate between men with varicocele from those without varicocele, and between fertile men with varicocele from those infertile with varicocele. Furthermore, the most important metabolites for group segregation are involved in the oxidative stress caused by varicocele.

Tannic acid as a precipitating agent of human plasma proteins.

The search for plasma proteins precipitation methods has been increasing due to the plasma protein therapeutic needs in world-wide. Thus, this work evaluates the tannic acid (TA) ability to precipitate proteins from human plasma. In this study, TA-plasma protein complexes were studied at different pH conditions, tannin/plasma ratio and reaction mixing time. The complexes formed from combinations of TA and plasma proteins were analyzed by gel electrophoresis, protein quantification, particle size, charge, mass spectrometry, microscopic image, and circular dichroism. It was possible to verify the precipitate formation in all tested pH values, with high precipitation at pH 5. The native PAGE analysis showed three mainly bands corresponding independent of the pHs used. It was possible to observe a gradual growing of precipitate protein in the first precipitation process (P1) when increased the TA/plasma ratio. 15 min of incubation was enough to precipitate 72.3% of proteins. Spectroscopic analyzes showed albumin signals and the electron microscopy analysis of IgG-TA confirmed the compact form of a precipitate. According to CD, formation of the IgG-TA complexes does not cause a major structural change of the protein. From the results obtained, it was possible to establish some parameters for plasma proteins precipitation using TA.

Proton nuclear magnetic resonance-based metabonomic models for non-invasive diagnosis of liver fibrosis in chronic hepatitis C: Optimizing the classification of intermediate fibrosis.

AIM: To develop metabonomic models (MMs), using 1H nuclear magnetic resonance (NMR) spectra of serum, to predict significant liver fibrosis (SF: Metavir ≥ F2), advanced liver fibrosis (AF: METAVIR ≥ F3) and cirrhosis (C: METAVIR = F4 or clinical cirrhosis) in chronic hepatitis C (CHC) patients. Additionally, to compare the accuracy of the MMs with the aspartate aminotransferase to platelet ratio index (APRI) and fibrosis index based on four factors (FIB-4). METHODS: Sixty-nine patients who had undergone biopsy in the previous 12 mo or had clinical cirrhosis were included. The presence of any other liver disease was a criterion for exclusion. The MMs, constructed using partial least squares discriminant analysis and linear discriminant analysis formalisms, were tested by cross-validation, considering SF, AF and C. RESULTS: Results showed that forty-two patients (61%) presented SF, 28 (40%) AF and 18 (26%) C. The MMs showed sensitivity and specificity of 97.6% and 92.6% to predict SF; 96.4% and 95.1% to predict AF; and 100% and 98.0% to predict C. Besides that, the MMs correctly classified all 27 (39.7%) and 25 (38.8%) patients with intermediate values of APRI and FIB-4, respectively. CONCLUSION: The metabonomic strategy performed excellently in predicting significant and advanced liver fibrosis in CHC patients, including those in the gray zone of APRI and FIB-4, which may contribute to reducing the need for these patients to undergo liver biopsy.

Diagnosis of coinfection by schistosomiasis and viral hepatitis B or C using 1H NMR-based metabonomics.

BACKGROUND: Diagnosis of liver involvement due to schistosomiasis in asymptomatic patients from endemic areas previously diagnosed with chronic hepatitis B (HBV) or C (HCV) and periportal fibrosis is challenging. H-1 Nuclear Magnetic Resonance (NMR)-based metabonomics strategy is a powerful tool for providing a profile of endogenous metabolites of low molecular weight in biofluids in a non-invasive way. The aim of this study was to diagnose periportal fibrosis due to schistosomiasis mansoni in patients with chronic HBV or HCV infection through NMR-based metabonomics models. METHODOLOGY/PRINCIPAL FINDINGS: The study included 40 patients divided into two groups: (i) 18 coinfected patients with schistosomiasis mansoni and HBV or HCV; and (ii) 22 HBV or HCV monoinfected patients. The serum samples were analyzed through H-1 NMR spectroscopy and the models were based on Principal Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA). Ultrasonography examination was used to ascertain the diagnosis of periportal fibrosis. Exploratory analysis showed a clear separation between coinfected and monoinfected samples. The supervised model built from PLS-DA showed accuracy, R2 and Q2 values equal to 100%, 98.1% and 97.5%, respectively. According to the variable importance in the projection plot, lactate serum levels were higher in the coinfected group, while the signals attributed to HDL serum cholesterol were more intense in the monoinfected group. CONCLUSIONS/SIGNIFICANCE: The metabonomics models constructed in this study are promising as an alternative tool for diagnosis of periportal fibrosis by schistosomiasis in patients with chronic HBV or HCV infection from endemic areas for Schistosoma mansoni.

Conduta na dor e prurido vulvar / Pain and pruritus vulvae management

Prurido e dor são as principais manifestações clínicas das doenças vulvares. Estes sintomas podem estar associados a processos inflamatórios, imunológicos, distúrbios metabólicos e neoplasias. Na dúvida, é sempre recomendável o estudo histopatológico. Quando não há definição etiológica, várias opções terapêuticas estão disponíveis: cremes tópicos, fármacos sistêmicos, operações de dessensibilização nervosa da vulva. A conduta terapêutica deve ser individualizada quando não há etiologia definida. São escassos os trabalhos científicos, com metodologia adequada, que abordam o tema. Portanto, anamnese e exame físico cuidadosos irão definir a melhor abordagem terapêutica

Pruritus and pain are common manifestations of vulvae diseases. The symptoms can be associated with inflammatory, immunologic, metabolic or neoplastic diseases. Undoubtedly, the histopathological exam is always recommended. When there is no etiologic definition, many therapeutic options are available: creams, systemic drugs, and surgical neural desensitization of the vulvae. When there is no precise etiology, therapeutical approach must be individualized. Scientific studies, with good methodology, are rare. Therefore, careful anamnesis and physical exam will point to the best therapeutical approach

Exames pré-operatórios nas cirurgias ginecológicas eletivas / Preoperative exams in elective gynecological surgeries

A solicitação rotineira e sem critérios de exames complementares em pacientesno período pré-operatório não deve ser realizada. A avaliação médica completa com abrangente anamnese eexame clínico permitem ao médico o julgamento dos exames realmente necessários. Quanto mais exames foremsolicitados, maior a chance de serem encontradas alterações nos resultados. Novas consultas, novos exames,atraso no procedimento cirúrgico e aumento do custo são as principais consequências de exame anormal semindicação de realização. Algumas entidades médicas formularam guidelines baseados no porte da cirurgia eno estado clínico da paciente, que servem de apoio para decisão de quais exames são fundamentais. Porém,cada instituição deve possuir seu próprio modelo de avaliação destes pacientes, otimizando o pré-operatório e,indiretamente, reduzindo os custos cada vez maiores dos sistemas de saúde.

The routine and criterionless solicitation of exams for patients in thepreoperative period should not be done. The complete clinical examination with anamnesis and physical examinationallows to the physician the judgment of the real necessary exams. The chances of finding alterations in tests arehigher as numerous exams are solicited. New medical consultations, new laboratory tests, delay in the surgicalprocedure and increase in the costs are the main consequences of an abnormal exam without medical indication.Some medical associations established guidelines according to the grade of the surgery and conditions of thepatient in order to support the decision of which exams are fundamental. However, each institution shouldestablish a model of assessment of these patients, which could optimize the preoperative period and, indirectly,reduce the increasing costs of health insurances.

Reconstruçäo de vulva pós-vulvectomia / Vulvar reconstruction after vulvectomy

Os autores apresentam sete casos de pacientes submetidas a vulvectomia com reconstruçao imediata, seis das quais eram portadoras de patologia maligna enquanto uma apresentava hidroadenite extensa e de longa duraçao. Sao analisadas as técnicas empregadas e ressaltada a importância da associaçao entre o ginecologista e o cirurgiao plástico na obtençao do melhor resultado.

Estudo epidemiológico do abortamento no Brasil / Epidemiological study of abortion in Brazil

Objetivo: avaliar a prevalência do abortamento induzido em relaçao ao abortamento espontâneo em instituiçoes hospitalares. Delineamento: estudo retrospectivo nao controlado. Local:cinco instituiçoes hospitalares localizadas em diferentes cidades do Brasil (Fortaleza, Recife, Curitiba, Rio de Janeiro e Campinas), de O1.09.1992 a 31.08.1993. Pacientes: 4.408 - Universidade Federal do Ceará (l.l17), Universidade Federal do Rio de Janeiro(l.OO4), Universidade Federal do Paraná (999), Universidade Estadual de Campinas (276) e Universidade Federal de Pernambuco (l.Ol2). Variáveis: perfil obstétrico, dados de planificaçao familiar, variáveis da esfera sócio-econômica, características do abortamento (diagnóstico, tratamento e complicaçoes). Resultados: as pacientes eram solteiras (60 por cento), com início de vida sexual na adolescência (88 por cento). A incidência do abortamento precoce foi de 81 por cento, e a curetagem só ou associada a antibióticos foi o tratamento usado em 95 por cento dos casos. A incidência de abortamento provocado foi de 19 por cento e em 80 por cento dos casos fármacos orais ou injetáveis foram o agente indutor. Conclusoes: a incidência de abortamento induzido é alta, principalmente em mulheres jovens, solteiras, pouco instruídas e com início de vida sexual precoce.