Use of SVM Methods with Surface-Based Cortical and Volumetric Subcortical Measurements to Detect Alzheimer`s Disease

Here, we examine morphological changes in cortical thickness of patients with Alzheimer`s disease (AD) using image analysis algorithms for brain structure segmentation and study automatic classification of AD patients using cortical and volumetric data. Cortical thickness of AD patients (n = 14) was measured using MRI cortical surface-based analysis and compared with healthy subjects (n = 20). Data was analyzed using an automated algorithm for tissue segmentation and classification. A Support Vector Machine (SVM) was applied over the volumetric measurements of subcortical and cortical structures to separate AD patients from controls. The group analysis showed cortical thickness reduction in the superior temporal lobe, parahippocampal gyrus, and enthorhinal cortex in both hemispheres. We also found cortical thinning in the isthmus of cingulate gyrus and middle temporal gyrus at the right hemisphere, as well as a reduction of the cortical mantle in areas previously shown to be associated with AD. We also confirmed that automatic classification algorithms (SVM) could be helpful to distinguish AD patients from healthy controls. Moreover, the same areas implicated in the pathogenesis of AD were the main parameters driving the classification algorithm. While the patient sample used in this study was relatively small, we expect that using a database of regional volumes derived from MRI scans of a large number of subjects will increase the SVM power of AD patient identification.

Matrix metalloproteinase-2 polymorphism is associated with prognosis in prostate cancer

Objective: Prostate cancer (PCa) is the most frequent tumor in males in Brazil. Single nucleotide polymorphisms (SNP) have been demonstrated in the promoter region of matrix metalloproteinases (MMPs) genes and have been associated with development and progression of some cancers. In this study, our aim was to investigate a possible relation between polymorphism of the promoter region of the MMP2 gene and classical prognostic parameters in prostate cancer. Materials and methods: Genomic DNA was extracted using conventional protocols. The DNA sequence containing the polymorphic site was amplified by real-time polymerase chain reaction, using fluorescent probes (TaqMan). Results: In patients with tumors of a higher stage (pT3), a polymorphic allele in the MMP2 gene was more frequent (P = 0.026) than in patients with lower tumor stage. A polymorphic allele in the MMP2 gene was more frequent in Gleason >= 7 than in Gleason <= 6 (P = 0.042). Conclusions: We conclude that MMP2 polymorphism can be used together with pathological stage and Gleason score to identify patients with worse prognosis. Our results illustrate the potential use of MMP2 SNP as a molecular marker for prostate cancer. (C) 2010 Elsevier Inc. All rights reserved.

Cavopulmonary anastomosis improves left ventricular assist device support in acute biventricular failure

Objective: Right ventricular failure during left ventricular assist device (WAD) support can result in severe hemodynamic compromise with high mortality. This study investigated the acute effects of cavopulmonary anastomosis on right ventricular loading and WAD performance in a model of severe biventricular failure. Methods: LVAD support was performed by means of centrifugal pump implantation in 14 anesthetized dogs (20-30 kg) with severe biventricular failure obtained by ventricular fibrillation induction. Animals were randomized to be submitted to classical cavopulmonary anastomosis (Glenn shunt) or to control group and were maintained under WAD support for 2 h. Left and right atrial, right ventricular and systemic pressures were monitored, white total pulmonary flow was simultaneously recorded by transonic flowmeters located on the superior vena cava and pulmonary trunk. Blood gas and venous lactate determinations were also obtained. Results: Ventricular fibrillation maintenance resulted in acute WAD performance impairment after 90 min in the control group, while animals with Glenn circuit maintained normal WAD pump flow (55 +/- 13 ml kg(-1) min(-1) vs 21 +/- 4 ml kg(-1) min(-1), p < 0.001) and better peripheral perfusion (blood lactate of 29 +/- 10 pg/ml vs 46 +/- 9 pg/ml, p < 0.001). Left and right atrial pressures did not change significantly, while right ventricular pressure was tower in animals with Glenn circuit (13 +/- 3 mmHg vs 22 +/- 8 mmHg, p = 0.005). Right ventricular unloading with Glenn shunt also resulted in superior total pulmonary flow (59 +/- 13 ml kg(-1) min(-1) vs 17 +/- 3 ml kg(-1) min(-1), p < 0.001). Conclusion: The concomitant use of cavopulmonary anastomosis during LVAD support in a model of severe biventricular failure limited right ventricular overloading and resulted in better hemodynamic performance. (C) 2008 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Fabry Disease in Hemodialysis Patients in Southern Brazil: Prevalence Study and Clinical Report

Background. Fabry disease (FD) is a lysosomal storage disorder caused by a deficiency of -Galactosidase A (-Gal A). Fabry nephropathy typically progresses throughout the fifth decade to end-stage renal disease (ESRD), requiring hemodialysis and/or kidney transplantation. Objective. To estimate the prevalence of FD among ESRD males on hemodialysis treatment in Rio Grande do Sul, the southernmost state of Brazil. Methods. Screening for -Gal A activity was performed by a dried blood spot (normal reference value: 1.5 nmoles/hour/mL). Positive screening results were confirmed by plasma -Gal A activity assay (reference value: 3.3 nmoles/hour/mL). Results. Five hundred fifty-eight male patients on hemodialysis were evaluated. Of these, only two had low -Gal A activity and were diagnosed with Fabry disease (0.36%). One of these, age 42, had left ventricular hypertrophy and renal manifestations of Fabry disease without the classic symptoms. The other, age 46, had the classical manifestations of angiokeratomas, acroparesthesias, hypohidrosis, and ocular opacities. Conclusions. Although the prevalence of Fabry disease was very low in our study (0.36%), routine screening of male hemodialysis patients would enable earlier identification of many other affected relatives in their families who might benefit from specific clinical treatment.

Reliability assessment of Cobb angle measurements using manual and digital methods

BACKGROUND CONTEXT: The vertebral spine angle in the frontal plane is an important parameter in the assessment of scoliosis and may be obtained from panoramic X-ray images. Technological advances have allowed for an increased use of digital X-ray images in clinical practice. PURPOSE: In this context, the objective of this study is to assess the reliability of computer-assisted Cobb angle measurements taken from digital X-ray images. STUDY DESIGN/SETTING: Clinical investigation quantifying scoliotic deformity with Cobb method to evaluate the intra- and interobserver variability using manual and digital techniques. PATIENT SAMPLE: Forty-nine patients diagnosed with idiopathic scoliosis were chosen based on convenience, without predilection for gender, age, type, location, or magnitude of the curvature. OUTCOME MEASURES: Images were examined to evaluate Cobb angle variability, end plate selection, as well as intra- and interobserver errors. METHODS: Specific software was developed to digitally reproduce the Cobb method and calculate semiautomatically the degree of scoliotic deformity. During the study, three observers estimated the Cobb angle using both the digital and the traditional manual methods. RESULTS: The results showed that Cobb angle measurements may be reproduced in the computer as reliably as with the traditional manual method, in similar conditions to those found in clinical practice. CONCLUSIONS: The computer-assisted method (digital method) is clinically advantageous and appropriate to assess the scoliotic curvature in the frontal plane using Cobb method. (C) 2010 Elsevier Inc. All rights reserved.

Evaluation of rhBMP-2 and Natural Latex as Potential Osteogenic Proteins in Critical Size Defects by Histomorphometric Methods

This in vivo study evaluated the osteogenic potential of two proteins, recombinant human bone morphogenetic protein-2 (rhBMP-2) and a protein extracted from natural latex (Hevea brasiliensis, P-1), and compared their effects on bone defects when combined with a carrier or a collagen gelatin. Eighty-four (84) Wistar rats were divided into two groups, with and without the use of collagen gelatin, and each of these were divided into six treatment groups of seven animals each. The treatment groups were: (1) 5 mu g of pure rhBMP-2; (2) 5 mu g of rhBMP-2/monoolein gel; (3) pure monoolein gel; (4) 5 mu g of pure P-1; (5) 5 mu g of P-1/monoolein gel; (6) critical bone defect control. The animals were anesthetized and a 6 mm diameter critical bone defect was made in the left posterior region of the parietal bone. Animals were submitted to intracardiac perfusion after 4 weeks and the calvaria tissue was removed for histomorphometric analysis. In this experimental study, it was concluded that rhBMP-2 allowed greater new bone formation than P-1 protein and this process was more effective when the bone defect was covered with collagen gelatin (P < 0.05). Anat Rec, 293:794-801, 2010. (C) 2010 Wiley-Liss, Inc.

Evaluation of Adult Chronic Chagas` Heart Disease Diagnosis by Molecular and Serological Methods

Chagas` disease caused by Trypanosoma cruzi is endemic in Latin America. T. cruzi presents heterogeneous populations and comprises two main genetic lineages, named T. cruzi I and T. cruzi II. Diagnosis in the chronic phase is based on conventional serological tests, including indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA), and diagnosis in the acute phase based on parasitological methods, including hemoculture. The objective of this study was to evaluate the diagnostic procedures of Chagas` disease in adult patients in the chronic phase by using a PCR assay and conventional serological tests, including TESA-blot as the gold standard. Samples were obtained from 240 clinical chronic chagasic patients. The sensitivities, compared to that of TESA-blot, were 70% for PCR using the kinetoplast region, 75% for PCR using the nuclear repetitive region, 99% for IIF, and 95% for ELISA. According to the serological tests results, we recommend that researchers assess the reliability and sensitivity of the commercial kit Chagatest ELISA recombinant, version 3.0 (Chagatest Rec v3.0; Wiener Lab, Rosario, Argentina), due to the lack of sensitivity. Based on our analysis, we concluded that PCR cannot be validated as a conventional diagnostic technique for Chagas` disease. These data have been corroborated by low levels of concordance with serology test results. It is recommended that PCR be used only for alternative diagnostic support. Using the nuclear repetitive region of T. cruzi, PCR could also be applicable for monitoring patients receiving etiologic treatment.

Classical and non-classical HLA molecules and p16(INK4a) expression in precursors lesions and invasive cervical cancer

Objectives: Viruses and turnout cells may regulate the expression of HLA molecules on the cell surface to escape immune system surveillance. Absence of classical HLA class I molecules may impair the action of specific cytotoxic cells, whereas non-classical HLA class I molecules may regulate innate and adaptive immune cells. We assess here the possible associations between classical/non-classical class I HLA and p16(INK4a) molecule expression in cervical biopsies of women infected with HPV, stratified according to grade of the lesion and HPV type. Study design: Cervical biopsies (N = 74) presenting cervical intraepithelial neoplasia grade 1 (CIN1) (n = 31), CIN2-3 (n = 19), and invasive cancer (n = 14) were evaluated alongside 10 normal cervical specimens. Results: HLA-A/B/C/G staining was observed in the early stages of HPV infection. A significant association was detected between HLA-A/B/C staining and HPV16/18 infection (OR = 0.12, 95%CI: 0.0163-0.7899; p = 0.04). HLA-E expression increased with the progression of the lesion (chi(2)-test for trend = 4.01; p = 0.05), and a significant association was found between HLA-E staining and HPV16/18 infection (OR = 11.25, 95%CI: 2.324-54.465; p = 0.003). Irrespective of the grade of the lesion, HLA-A/B/C staining and p16(INK4a) presented a good concordance (Kappa: 0.67). Conclusions: HLA-E overexpression seemed to be associated with invasive cancer and HPV16/18 infection. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Evaluation of computational methods for the reconstruction of HLA haplotypes

Human leukocyte antigen (HLA) haplotypes are frequently evaluated for population history inferences and association studies. However, the available typing techniques for the main HLA loci usually do not allow the determination of the allele phase and the constitution of a haplotype, which may be obtained by a very time-consuming and expensive family-based segregation study. Without the family-based study, computational inference by probabilistic models is necessary to obtain haplotypes. Several authors have used the expectation-maximization (EM) algorithm to determine HLA haplotypes, but high levels of erroneous inferences are expected because of the genetic distance among the main HLA loci and the presence of several recombination hotspots. In order to evaluate the efficiency of computational inference methods, 763 unrelated individuals stratified into three different datasets had their haplotypes manually defined in a family-based study of HLA-A, -B, -DRB1 and -DQB1 segregation, and these haplotypes were compared with the data obtained by the following three methods: the Expectation-Maximization (EM) and Excoffier-Laval-Balding (ELB) algorithms using the arlequin 3.11 software, and the PHASE method. When comparing the methods, we observed that all algorithms showed a poor performance for haplotype reconstruction with distant loci, estimating incorrect haplotypes for 38%-57% of the samples considering all algorithms and datasets. We suggest that computational haplotype inferences involving low-resolution HLA-A, HLA-B, HLA-DRB1 and HLA-DQB1 haplotypes should be considered with caution.

Comparative analysis of two immunohistochemical methods for antigen retrieval in the optical lobe of the honeybee Apis mellifera: Myosin-v assay

The present study compared two heating methods currently used for antigen retrieval (AR) immunostaining: the microwave oven and the steam cooker. Myosin-V, a molecular motor involved in vesicle transport, was used as a neuronal marker in honeybee Apis mellifera brains fixed in formalin. Overall, the steam cooker showed the most satisfactory AR results. At 100 degrees C, tissue morphology was maintained and revealed epitope recovery, while evaporation of the AR solution was markedly reduced; this is important for stabilizing the sodium citrate molarity of the AR buffer and reducing background effects. Standardization of heat-mediated AR of formalin-fixed and paraffin-embedded tissue sections results in more reliable immunostaining of the honeybee brain.

Methods for exploring the morpho-functional relations of the aortic depressor nerve in experimental diabetes

The present study investigated morpho-functional relations of the aortic depressor nerve (ADN) 5, 15 and 120 days after the onset of streptozotocin-induced diabetes in rats. Time control animals received vehicle. Under pentobarbital anesthesia, ADN activity was recorded simultaneously with arterial pressure. After the recordings, nerves were prepared for light microscopy study and morphometry. ADN function was accessed by means of pressure-nerve activity curve (fitted by sigmoidal regression) and cross-spectral analysis between mean arterial pressure (MAP) and ADN activity. The relation between morphological (myelinated fibers number and density, total myelin area, total fiber area and percentage of occupancy) and functional (gain, signal/noise relation, frequency) parameters were accessed by linear regression analysis and correlation coefficient calculations. Functional parameters obtained by means of the sigmoidal regression curve as well as by cross-spectral analysis were similar in diabetic and control rats. Morphometric parameters of the ADN were similar between groups 5 days after the onset of diabetes. Average myelin area and myelinated fiber area were significantly smaller on diabetic rats 15 and 120 days after the onset of diabetes, being the myelinated fiber and respective axons area and diameter also smaller on 120 days group. Nevertheless, G ratio (ratio between axon and fiber diameter) was nearly 0.6 and not different between groups or experimental times. No significant relationship between morphological and functional parameters was detected in all experimental groups. The present study suggests that ADN diabetic neuropathy was time-dependent, with damage to myelinated fibers to be the primary event, not evidenced by physiological methods. (C) 2010 Elsevier B.V. All rights reserved.

Keyhole sign: how specific is it for the diagnosis of posterior urethral valves?

Objectives Posterior urethral valves (PUV) are the most common cause of renal impairment in boys during early childhood. Although antenatal suspicion of this pathology has become quite common in recent years, prenatal diagnosis remains challenging. The aim of this study was to evaluate the predictive value of different ultrasound criteria currently used to diagnose PUV. Methods We reviewed the antenatal and postnatal files of 54 male patients referred to our center from 2000 to 2006 after detection of fetal bilateral hydronephrosis. The following ultrasound criteria were evaluated in relation to the postnatal diagnosis of P U V: amniotic fluid volume, bladder wall thickness, bladder dilatation and the presence of the `keyhole sign`. Results Forty-two fetuses (77.8%) were suspected to have PUV on prenatal examination. Out of these, 29 (69.0%) had PUV confirmed postnatally. The sensitivity and specificity of the antenatal diagnosis of PUV were 94% and 43%, respectively. Increased bladder wall thickness and bladder dilatation were highly associated with the diagnosis of PUV (P < 0.001). However, a thick-walled bladder was observed in 39.1% and a dilated bladder in 47.8% of the infants with a postnatal diagnosis other than PUV. The presence of the keyhole sign was not found to predict a diagnosis of PUV (P = 0.27). Conclusion In this series the use of classical prenatal ultrasound signs to diagnose PUV showed high sensitivity but low specificity. The best diagnostic indicators were increased bladder wall thickness and dilatation of the bladder. The keyhole sign was not found to be a reliable predictor of PUV. Copyright (C) 2009 ISUOG. Published by John Wiley & Sons, Ltd.

Evaluation of lignin contents in tropical forages using different analytical methods and their correlations with degradation of insoluble fiber

We compared the lignin contents of tropical forages by different analytical methods and evaluated their correlations with parameters related to the degradation of neutral detergent fiber (NDF). The lignin content was evaluated by five methods: cellulose solubilization in sulfuric acid [Lignin (sa)], oxidation with potassium permanganate [Lignin (pm)], the Klason lignin method (KL), solubilization in acetyl bromide from acid detergent fiber (ABLadf) and solubilization in acetyl bromide from the cell wall (ABLcw). Samples from ten grasses and ten legumes were used. The lignin content values obtained by gravimetric methods were also corrected for protein contamination, and the corrected values were referred to as Lignin (sa)p, Lignin (pm)p and KLp. The indigestible fraction of NDF (iNDF), the discrete lag (LAG) and the fractional rate of degradation (kd) of NDF were estimated using an in vitro assay. Correcting for protein resulted in reductions (P < 0.05) in the lignin contents as measured by the Lignin (sa), Lignin (pm) and, especially, the KL methods. There was an interaction (P < 0.05) of analytical method and forage group for lignin content. In general, LKp method provided the higher (P < 0.05) lignin contents. The estimates of lignin content obtained by the Lignin (sa)p, Lignin (pm)p and LKp methods were associated (P > 0.05) with all of the NDF degradation parameters. However, the strongest correlation coefficients for all methods evaluated were obtained with Lignin (pm)p and KLp. The lignin content estimated by the ABLcw method did not correlate (P > 0.05) with any parameters of NDF degradation. There was a correlation (P < 0.05) between the lignin content estimated by the ABLadf method and iNDF content. Nonetheless, this correlation was weaker than those found with gravimetric methods. From these results, we concluded that the gravimetric methods produce residues that are contaminated by nitrogenous compounds. Adjustment for these contaminants is suggested, particularly for the KL method, to express lignin content with greater accuracy. The relationships between lignin content measurements and NDF degradation parameters can be better determined using KLp and Lignin (pm)p methods. (C) 2011 Elsevier B.V. All rights reserved.

Short communication: Identification of subclinical cow mastitis pathogens in milk by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Subclinical mastitis is a common and easily disseminated disease in dairy herds. Its routine diagnosis via bacterial culture and biochemical identification is a difficult and time-consuming process. In this work, we show that matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) allows bacterial identification with high confidence and speed (1 d for bacterial growth and analysis). With the use of MALDI-TOF MS, 33 bacterial culture isolates from milk of different dairy cows from several farms were analyzed, and the results were compared with those obtained by classical biochemical methods. This proof-of-concept case demonstrates the reliability of MALDI-TOF MS bacterial identification, and its increased selectivity as illustrated by the additional identification of coagulase-negative Staphylococcus species and mixed bacterial cultures. Matrix-assisted laser desorption-ionization mass spectrometry considerably accelerates the diagnosis of mastitis pathogens, especially in cases of subclinical mastitis. More immediate and efficient animal management strategies for mastitis and milk quality control in the dairy industry can therefore be applied.

Validation of non-fluorescent methods to reliably detect acrosomal and plasma membrane integrity of common marmoset (Callithrix jacchus) sperm

Simple, rapid and stable sperm evaluation methods which have been optimized for common marmoset (Callithrix jacchus) are critical for studies involving collection and evaluation of sperm in the field. This is particularly important for new species groups such as Callitrichidae where the sperm have been little studied. Of this family, C jacchus is the best known, and has been chosen as a model species for other members of the genus Callithrix. The fundamental evaluation parameters for sperm of any species are viability and acrosomal status. Semen samples were collected by penile vibratory stimulation. To evaluate sperm plasma membrane integrity, Eosin-Nigrosin was tested here for the common marmoset sperm to be used under field conditions. Further, a non-fluorescent stain for acrosome, the ""Simple"" stain, developed for domestic and wild cats, was tested on common marmoset sperm. This was compared with a fluorescent staining, Fluorescein isothiocyanate-Pisum sativum agglutinin (FITC-PSA), routinely used and validated for common marmoset at the German Primate Centre to evaluate acrosomal integrity. Results obtained with the ""Simple"" stain showed a marked differentiation between sperm with intact and non-intact acrosome both with and without ionophore treatment and closely correlated with results obtained with FITC-PSA. Temperature had no effect on the results with the ""Simple"" stain and the complete processing is simple enough to be carried out under field conditions. These findings indicated that the ""Simple"" stain and Eosin-Nigrosin provide rapid and accurate results for C. jacchus sperm and that those methods can be reliably used as field tools for sperm evaluation for this species. (c) 2008 Elsevier Inc. All rights reserved.