Simultaneous absorption of UV-vis and circular dichroism to measure enantiomeric concentrations of praziquantel under nonlinear conditions.

Beer-Lambert-Bouguer law is for a limiting case and, therefore, it is not useful to describe the relationship between absorption signal and enantiomer concentration in a stream when there are nonlinear phenomena present. In this work, the Chiral Detector (CD-2095 JASCO) equipment was used to measure simultaneously the UV-Vis and circular dichroism (CD) signals of a stream with different compositions of praziquantel enantiomers. The tested models were calibrated (parameter estimation) and validated using the Leave-One-Out Cross Validation (LOOCV) method. Both UV-vis and CD signals were absorbed differently in mixtures in comparison to pure solutions, indicating a nonlinear relationship between the absorbed signal and the enantiomer concentration in a mixture stream. Empirical mathematical relationships were tested for each signal (UV-vis and CD) and the pair of equations was evaluated using the Mean Square Error (MSE) metric for each enantiomer concentration (MSEL and MSED) and the pair of equations with the smallest MSEt (=MSEL + MSED) metric was chosen. Confidence interval analysis helped to find even simpler equations in comparison to the chosen ones. Higher nonlinearity was observed for a mixture with low L-PZQ concentration. The developed methodology allowed the choice of an empiric model to give good predictions in a wide range of concentration, what is of utmost importance for monitoring and automatic control purposes, for instance.

Leucismo em jacaretinga: relato de caso / Leucism in jacaretinga: case report

Dentre os crocodilianos com ocorrência no Brasil, o Caiman crocodilus (Linnaeus, 1758) é a espécie de maior frequência, porém sua presença em estudos científicos restringe-se a levantamentos faunísticos, na maioria das vezes. O leucismo, também conhecido como albinismo parcial, é uma anomalia cromática ainda pouco conhecida. Indivíduos portadores dos genes que condicionam a doença apresentam ausência de pigmentação em uma parte ou em todo o corpo, porém os olhos não apresentam alteração. O objetivo deste trabalho foi realizar o primeiro registro de Caiman crocodilus com leucismo no mundo.(AU)

Among crocodilians in Brazil, Caiman crocodilus (Linnaeus, 1758) is the most frequent species, but its presence in scientific studies is mostly restricted to faunal surveys. Leukism, also known as partial albinism, is a still little known chromatic anomaly. Individuals with genes that condition the disease present no pigmentation in one part or in the whole body, but the eyes did not change. The objective of this work was to perform the first record of Caiman crocodilus with leucismo in the world.(AU)

A New Approach for Dental Bleaching Using Violet Light With or Without the Use of Whitening Gel: Study of Bleaching Effectiveness.

The objective of this study was to evaluate the effectiveness of violet light-emitting diodes (LEDs) in dental bleaching treatment when used in conjunction with bleaching gels containing different concentrations of hydrogen peroxide (HP). Here, 90 bovine teeth (n=15) were randomly assigned to the following groups: GI, placebo without light; GII, 35% HP without light; GIII, 17.5% HP without light; GIV, placebo with violet LED; GV, 35% HP with violet LED; and GVI, 17.5% HP with violet LEDs. Three bleaching sessions of 45 minutes were conducted; 21 cycles involving one minute of irradiation by violet LEDs with 30-second intervals were performed during each session of bleaching (GIV, GV, and GVI). Color changes (ΔE, ΔL, Δa, and Δb) were analyzed using a visible ultraviolet light spectrophotometer 7 days after each bleaching session. The mean ΔE, ΔL, Δa, and Δb values were compared between groups by analysis of variance and Tukey tests, with a significance level of 5%. The groups treated with 35% HP had higher ΔE and ΔL and lower Δb values, regardless of whether violet light was used. The group that received only violet LED differed from the control group in terms of ΔE, and the group treated with 17.5% HP and violet LED presented higher ΔE values than the group treated with 17.5% HP only. Thus, violet light did not influence bleaching efficacy when using 35% HP, but when used in conjunction with 17.5% HP, it increased the bleaching efficacy. Moreover, use of the violet LED only also prompted a bleaching effect, although it was less marked.

Serum testosterone, sperm quality, cytological, physicochemical and biochemical characteristics of the prostatic fraction of dogs with prostatomegaly.

Prostatomegaly is a common finding in older non-neutered dogs. This study compared the serum testosterone, sperm quality and characteristics of the prostatic fraction between healthy dogs and dogs with prostatomegaly. Blood samples of ten dogs (five dogs from each group) were taken for serum testosterone measurement. Sperm motility, vigour, concentration, viability, membrane functionality and morphology were analysed in sperm-rich fraction. Osmolality, pH, cell types, and albumin, haemoglobin, acid phosphatase, alkaline phosphatase, glucose, triglycerides, cholesterol, calcium, phosphorus, magnesium and chloride were analysed in prostatic fraction. Dogs with prostatomegaly have the lowest sperm motility, vigour, concentration and functional membrane. Dogs with prostatomegaly have the highest glucose, triglycerides and cholesterol. Glucose was the only constituent positively correlated with serum testosterone and prostate volume. It can be concluded that dogs with prostatomegaly have poorer sperm quality, and glucose, triglycerides and cholesterol in prostatic fraction can be used as prostatomegaly biomarkers.

Canine reproductive ultrasound examination for predicting future sperm quality.

The reproductive potential of male animals is commonly evaluated using a breeding soundness examination incorporating B-mode ultrasound examination of the testes and recently Doppler ultrasound examination of the testicular arteries. These techniques may detect testicular normality or pathology, and while some measured parameters are associated with semen quality at the time of ultrasound examination, few studies have investigated the relationship with future semen quality. We hypothesized that B-mode and Doppler ultrasound measurements would correlate with future semen quality. Within two studies, we investigated the relationship between ultrasound measured testicular volume, testicular echogenicity, testicular homogeneity, subjective assessment of the testicular parenchyma, testicular artery resistance index, and pulsatility index with subsequent semen quality. Fifty-five normal fertile dogs of which 29 had stable semen quality and 26 had a subsequent decline in semen quality were examined during a 6-month period commencing 62 days after the ultrasound examination. Statistical analysis showed that no ultrasound parameters were predictive of future total sperm output or percentage live normal sperm. However, mean testicular echogenicity was positively related to future sperm motility (t = 2.202, p = .039). We conclude that quantitative ultrasound assessment of the appearance of the testicular parenchyma has potential for the evaluation of future semen quality in dogs.

Nonlinear model predictive control applied to the separation of praziquantel in simulated moving bed chromatography.

An adaptive nonlinear model predictive control of a simulated moving bed unit for the enantioseparation of praziquantel is presented. A first principle model was applied at the proposed purity control scheme. The main concern about this kind of model in a control framework is in regard to the computational effort to solve it; however, a fast enough solution was achieved. In order to evaluate the controller's performance, several cases were simulated, including external pumps and switching valve malfunctions. The problem of plant-model mismatch was also investigated, and for that reason a parameter estimation step was introduced in the control strategy. In every studied scenario, the controller was able to maintain the purity levels at their set points, which were set to 99% and 98.6% for extract and raffinate, respectively. Additionally, fast responses and smooth actuation were achieved.

Mercury and methyl mercury in fishes from Bacajá River (Brazilian Amazon): evidence for bioaccumulation and biomagnification.

This study assessed total mercury (THg) and methyl mercury (MeHg) concentrations, bioaccumulation and biomagnification of THg through the food web in fishes consumed by indigenous communities of Bacajá River, the largest tributary of the right bank of Xingu River. In total, 496 fish (22 species) were sampled. Nine species had THg concentrations above the limit recommended by the World Health Organisation (0·5 µg g(-1) wet mass), and one exceeded the recommended level for Hg in predatory fishes by Brazilian law (1·0 µg g(-1) ). The average concentration of THg increased significantly with trophic guild (herbivorous to piscivorous) and trophic level, with higher accumulation in fishes with greater total length. Ninety-six per cent of all mercury was methylated. These results suggest that feeding habits determine THg concentrations in fishes and that Hg elimination rate is slow during growth, which allows greater accumulation. These findings show that fishes in the Bacajá River contain high concentrations of THg and MeHg.

Combined Genome-Wide CSF Aß-42's Associations and Simple Network Properties Highlight New Risk Factors for Alzheimer's Disease.

The abnormal deposition of amyloid-ß protein in the brain plays an important role in Alzheimer's disease (AD), being considered a potential clinical biomarker. To investigate genetic associations with amyloid-ß we used biomarker data and genome-wide variants from individuals with AD and mild cognitive impairment in the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. We used a standard linear model and retested the associations with a mixed linear model to correct the residual sample structure. Both methods' results showed two identical significant SNPs associated with the A ß-42 levels in CSF (rs2075650 at intron region TOMM40 with p-value ≥ 1 × 10-16 and rs439401 in the intergenic region of LOC100129500 and APOC1 with p-value ≥ 1 × 10-9) and highlighted APOC1 and TOMM40, which are well-known genes previously associated with AD. Extending our analysis, we considered possible candidate genes mapped to SNPs with p-value ≥ 1 × 10-6 to explore gene-set enrichment e gene-gene network analysis, which reveals genes related to synaptic transmission, transmission of nerve impulses, cell-cell signaling and neurological processes. These genes require fine mapping and replication studies to allow more detailed understanding of how they may contribute to the genetic architecture of AD.

Natural breeding sites of phlebotomine sand flies (Diptera: Psychodidae) on Marambaia Island, Rio de Janeiro State, Brazil.

Immature phlebotomine sand flies develop in soils with essential and ideal characteristics for their life cycle, such as organic matter, humidity, temperature and low levels of light. Information regarding the potential breeding places of these dipterans is fundamental to understand the epidemiology and ecology of leishmaniasis, in addition to its importance to control them. In the present study, we aimed to find natural breeding sites of sand flies on Marambaia Island with the aid of emergence traps and direct search of immature forms using the flotation technique with saturated sugar solution in organic substrates of the region. Both methods were effective, with a total of 42 specimens of six different species - including some species that participate in the transmission cycle of American Tegumentary Leishmaniasis - collected by the emergence traps, and five immature forms obtained by floatation technique. However, further studies are still necessary, mainly with respect to the ecology and biology of immature sandfly stages, so that control measures focused on breeding sites can produce positive sustainable results in natural environments.

Exaggerated blood pressure response during the exercise treadmill test as a risk factor for hypertension.

Exaggerated blood pressure response (EBPR) during the exercise treadmill test (ETT) has been considered to be a risk factor for hypertension. The relationship of polymorphisms of the renin-angiotensin system gene with hypertension has not been established. Our objective was to evaluate whether EBPR during exercise is a clinical marker for hypertension. The study concerned a historical cohort of normotensive individuals. The exposed individuals were those who presented EBPR. At the end of the observation period (41.7 months = 3.5 years), the development of hypertension was analyzed within the two groups. Genetic polymorphisms and blood pressure behavior were assessed as independent variables, together with the classical risk factors for hypertension. The I/D gene polymorphism of the angiotensin-converting enzyme and M235T of angiotensinogen were ruled out as risk factors for hypertension. EBPR during ETT is not an independent influence on the chances of developing hypertension. No differences were observed between the hypertensive and normotensive individuals regarding gender (P = 0.655), skin color (P = 0.636), family history of hypertension (P = 0.225), diabetes mellitus (P = 0.285), or hypertriglyceridemia (P = 0.734). The risk of developing hypertension increased with increasing body mass index (BMI) and advancing age. The risk factors, which independently influenced the development of hypertension, were age and BMI. EBPR did not constitute an independent risk factor for hypertension and is probably a preclinical phase in the spectrum of normotension and hypertension.

Exaggerated blood pressure response during the exercise treadmill test as a risk factor for hypertension

Exaggerated blood pressure response (EBPR) during the exercise treadmill test (ETT) has been considered to be a risk factor for hypertension. The relationship of polymorphisms of the renin-angiotensin system gene with hypertension has not been established. Our objective was to evaluate whether EBPR during exercise is a clinical marker for hypertension. The study concerned a historical cohort of normotensive individuals. The exposed individuals were those who presented EBPR. At the end of the observation period (41.7 months = 3.5 years), the development of hypertension was analyzed within the two groups. Genetic polymorphisms and blood pressure behavior were assessed as independent variables, together with the classical risk factors for hypertension. The I/D gene polymorphism of the angiotensin-converting enzyme and M235T of angiotensinogen were ruled out as risk factors for hypertension. EBPR during ETT is not an independent influence on the chances of developing hypertension. No differences were observed between the hypertensive and normotensive individuals regarding gender (P = 0.655), skin color (P = 0.636), family history of hypertension (P = 0.225), diabetes mellitus (P = 0.285), or hypertriglyceridemia (P = 0.734). The risk of developing hypertension increased with increasing body mass index (BMI) and advancing age. The risk factors, which independently influenced the development of hypertension, were age and BMI. EBPR did not constitute an independent risk factor for hypertension and is probably a preclinical phase in the spectrum of normotension and hypertension.

Revising the M235T polymorphism position for the AGT gene and reporting a modifying variant in the Brazilian population with potential cardiac and neural impact.

There is a growing need to curate the overwhelming amount of sequencing data which is available in many public databases. For instance, new information shows that the M235T polymorphism at the angiotensinogen gene (AGT) is actually positioned at the position corresponding to the amino acid 268 and not 235. This polymorphism is filled as rs699 in the NCBI SNP database and results in the synthesis of a threonine (T) instead of a methionine (M). It has been widely studied and associated as an important risk factor for several vascular and neuropsychiatric conditions. We faced this new situation during the targeted sequencing of 360 chromosomes from Brazilian subjects studied for the M235T polymorphism, leading to the identification of a novel variation (rs141900991). This report explores the potential impact of such a dinucleotide variation, which promotes the change of alanine (A) to serine (S) at the AGT protein structure (A237S). Considering the previous M268T variation at the four possible haplotypes combined (MA, MS, TA and TS), we performed a comparative hydrophobicity simulation, using the Kyte-Doolittle algorithm, available at the CLB Bio workbench, in the four possible haplotypes. Additional simulations were performed using the programs PolyPhen, I-Mutant and SIFT, in order to evaluate the pathogenicity of both mutations. The predicted hydrophobicity decreases of a similar magnitude, with both MS and TA haplotypes, but the presence of both variations induces a major decrease in hydrophobicity, suggesting a cumulative effect, with possible modifying effect since that this variation per se would limit the hydrophobicity range and the latter chances in finding significant phenotype differences. A better characterization of this kind of variant is particularly important because the current genome wide scan analyses in complex disorders with cardiac or neural etiology are not generating reliable findings, especially if we consider the huge investment with such approach. Additional and unknown variations like this one, with potential modifying effect, might be more common than previously expected.

Exploring the implications of INDELs in neuropsychiatric genetics: challenges and perspectives.

The decade passed after publishing the Human Genome first draft faced an enormous growth at the understanding of the genomic variation among different subjects, populations, and groups of patients. Single nucleotide polymorphisms (SNPs) and insertion or deletions (INDELs) have been increasingly recognized as a major type of genetic variations, with potential impact in protein activities and gene expression changes observed in complex genetic traits, like neuropsychiatric diseases. INDELs represent the second most common class of variations after SNPs, but there is still an important gap between the number of INDELs reported and the actual knowledge about the functional implications of such variations. There are approximately 10 million SNPs already reported, and the human populations are expected to collectively harbor at least 1.6-2.5 million INDELs. One of the major challenges is to find better platforms to screen for INDELs in a high throughput manner. The discordance in between the data from different studies might be explained by the diverse approaches employed to sequence the genomes with variable platforms. Short INDEL variations increased the scope of genetic markers in human genetic diseases, and various studies showed that common microdeletions and smaller INDELs might be highly associated with neuropsychiatric diseases such as schizophrenia, autism, mental retardation, and Alzheimer disease. The rapidly increasing amount of resequencing, genotyping, and personal genome data generated by large-scale genetic human projects require the development of integrated bioinformatics tools able to efficiently manage and analyze these genetic data. Our group is currently dealing with different approaches that might optimize sequencing and bioinformatics analyses of short INDELs to broaden our research capabilities of identifying those intriguing genetic variations. Hopefully, INDELs might become a new trend in association studies in neuropsychiatric genetics since so far the level of significant and positive associations with the standard SNPs reported presents limited predictive application.

Limnological changes in Dom Helvécio Lake (South-East Brazil): natural and anthropogenic causes.

In order to verify changes in physical, chemical and biological features of Dom Helvécio Lake (South-East Brazil), this study compares previous and recent data obtained from limnological investigations over three decades. Plankton species composition and density together with environmental data from 1978, 1983, and during 1999 to 2006 showed changes driven by seasonal climatic forces or by anthropogenic causes. Changes in diversity are shown as a consequence of alternation of rainy and dry periods and introduction of exotic fish species. Finally, suggestions are made for improving conservation efforts in the area, through planned actions and monitoring programmes.

Cytogenetic contributions for the study of the Amazonian Engystomops (Anura; Leiuperidae) assessed in the light of phylogenetic relationships.

Genetic divergence and speciation mechanisms of the Amazonian Engystomops frog have been inferred mainly from mtDNA sequences, microsatellite and male advertisement call. Although many aspects of this divergence remain unclear, cytogenetic analyses of Amazonian Engystomops populations are described and are compared to the relationships inferred from mitochondrial and nuclear DNA sequence data. High cytogenetic variation distinguished karyotypic patterns among the populations, even between populations which had no prezygotic isolation previously inferred from mating call analysis. Interestingly, the Puyo and Acre populations, which are in different clades, showed heteromorphic sex chromosomes (XX/XY), not identified in the other Ecuatorian populations analyzed. The analysis of a specimen collected in a site near Yasuní (Ecuador) which was cytogenetically related to the specimens from Puyo (Ecuador), was also phylogenetically closely related these specimens. In the rhodopsin nucleotide sequences, six polymorphic sites were identified and various specimens were heterozygous for them. All the data presented herein, in conjunction with those previously reported, corroborate the hypothesis that Engystomops petersi is a complex of distinct species. It also indicates that karyotypic evolution patterns may have played a substantial role in the Engystomops speciation and the occurrence of sporadic mating events between divergent evolutive lineages is discussed.

Molecular and serological characterization of group a rotavirus isolates obtained from hospitalized children in Goiânia, Brazil, 1998-2000.

Fecal samples positive for rotavirus group A ( n=120) were analyzed by enzyme immunoassay-monoclonal antibody (EIA-MAb) serotyping and/or reverse transcription/multiplex polymerase chain reaction (PCR) amplification to determine the prevalence of the [P] and G genotypes. The most prevalent G genotype/serotype detected was G1 (76.7%), followed by G2 (5.0%). Six samples were characterized as G9 by multiplex PCR, and one sample was characterized as G3 by EIA-MAb. The combinations of [P] and G genotypes found were P[8] and G1 (20.8%), P[6] and G1 (10.8%), P[6] and G9 (4.2%), P[8] and G2 (1.7%), and P[6] and G2 (0.8%). The diversity of rotavirus group A [P] and G genotypes/serotypes reinforces the need for continuous characterization of rotaviruses circulating in populations in Brazil.

Resultados preliminares da utilizaçäo de cultivos de anéis de traquéia para o estudo de estirpes brasileiras do vírus da bronquite infecciosa das galinhas / A preliminary use of tracheal organ cultures for evaluating Brazilian infectious bronchitis virus strains

Tracheal organ cultures (TOC) were prepared and used for evaluating four Brazilian isolates of infectious bronchitis virus (IBV). IBV field isolates and vaccine strains were titrated in TOC and results compared to those from chicken embrionated eggs. Serum neutralization (SN) employing IBV strain-specific serum was performed for evaluating relationships between isolates. Titration results of tests performed in TOC or eggs were in mutual agreement and were considered for validating the adapted TOC methodology as alternative for virological studies in our laboratory. Sera specific to M41 (Massachusetts) or A5968 (Connecticut) did neutralize their respective IBV strains only. Field strains 208 and 29-78 specific sera did neutralize Massachusetts serotype strains M41 and H120, but PM2 serum did only M41. Strain PM4 specific serum did not neutralize any of the reference IBV analyzed, including M41, A5968 and H120 and may indicate that the isolate is serologically different from the Massachusetts serotype, currently adopted for vaccine strains in Brazil