Genetic variants in glucocorticoid and mineralocorticoid receptors are associated with concentrations of plasma cortisol, muscle glycogen content, and meat quality traits in male Nellore cattle.

The glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) are key components in the regulation of the hypothalamic-pituitary-adrenal neuroendocrine axis and coordinate the physiological response to stress agents to reestablish homeostasis. Genetic variations of GR (NR3C1) and MR (NR3C2) genes could explain the alterations in animals to adapt to challenges, and therefore, their influence on production traits. The present study aimed to identify single-nucleotide polymorphisms (SNPs) in the bovine NR3C1 and NR3C2 genes and explore their associations to relevant traits of beef cattle production. Genotypes and phenotypes were collected from 241 male Nellore cattle (119 noncastrated and 122 castrated surgically) with an average of 24 ± 1.2 mo of age and live weight of 508 ± 39 kg. The traits evaluated were concentrations of plasma adrenocorticotropic hormone (ACTH) and cortisol, muscle glycogen and lactate content, and pH, color, cooking loss, and shear force of longissimus thoracis measured on the 1st, 7th, and 14th days postmortem. Five SNPs were identified, 2 in the NR3C1 gene and 3 in the NR3C2 gene. There was an associative relationship between the SNP NR3C1_1 g.3293A>G and postmortem plasma concentration of cortisol (P = 0.0008). The SNPs NR3C2_1 g.115T>C and NR3C2_2 g.570T>C were associated with muscle glycogen content (P = 0.0306 and P = 0.0158), postmortem plasma concentration of ACTH (P = 0.0118 and P = 0.0095), and cooking loss of the steak aged 1 d (P = 0.0398 and P = 0.0423). Haplotype analysis showed associations of GR haplotypes with postmortem plasma concentrations of cortisol and MR haplotypes with meat color, cooking losses, muscle glycogen content, and plasma concentrations of ACTH. The associations observed in the present study show that SNPs in GR and MR genes are related with changes of hypothalamic-pituitary-adrenal axis activity and metabolic profile in cattle, leading to individual variation in meat quality traits.

Novel sensory surface for creatine kinase electrochemical detection.

This work describes a novel concept of biosensor for quantifying enzymes, where the substrate is immobilized directly over the working area of a screen printed electrode (Au-SPE). This concept is applied here to creatine kinase isoenzyme (CK-MB), a cardiac biomarker in ischemic conditions. It acts as a phospho-transferase on creatine (Crea), requiring the presence of phosphate. So, the phosphorylated form of creatine (Pcrea) was immobilized on the Au/SPE previously aminated with cysteamine (Cys) by self-assembling monolayer technique. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) studies were used to follow the chemical modifications in the Au-SPE. Since Pcrea is an electroactive species at low potential, its consumption over the platform by the enzyme changed the electrical response of the biosensor. So, CK-MB determination has been achieved in mediator free-conditions due the redox proprieties of the Pcrea. The analytical features of the resulting biosensor were studied by square wave voltammetry (SWV). The limit of detection was 0.11 µg/mL and the slope was -0.029(± 0.0035) µA × mL/µg. The interference effect of troponin T (TnT), bovine serum albumin (BSA) and myoglobin (Myo) in the performance of the sensor was tested and good selectivity was observed. The biosensor was successfully applied to biological fluids, showing good stability at room temperature and excellent sensitivity and selectivity. This new concept of biosensor is especially useful for point of care (POC) applications, due to the low cost and small size of the final device.

Smart plastic antibody material (SPAM) tailored on disposable screen printed electrodes for protein recognition: application to myoglobin detection.

This work introduces two major changes to the conventional protocol for designing plastic antibodies: (i) the imprinted sites were created with charged monomers while the surrounding environment was tailored using neutral material; and (ii) the protein was removed from its imprinted site by means of a protease, aiming at preserving the polymeric network of the plastic antibody. To our knowledge, these approaches were never presented before and the resulting material was named here as smart plastic antibody material (SPAM). As proof of concept, SPAM was tailored on top of disposable gold-screen printed electrodes (Au-SPE), following a bottom-up approach, for targeting myoglobin (Myo) in a point-of-care context. The existence of imprinted sites was checked by comparing a SPAM modified surface to a negative control, consisting of similar material where the template was omitted from the procedure and called non-imprinted materials (NIMs). All stages of the creation of the SPAM and NIM on the Au layer were followed by both electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). AFM imaging was also performed to characterize the topography of the surface. There are two major reasons supporting the fact that plastic antibodies were effectively designed by the above approach: (i) they were visualized for the first time by AFM, being present only in the SPAM network; and (ii) only the SPAM material was able to rebind to the target protein and produce a linear electrical response against EIS and square wave voltammetry (SWV) assays, with NIMs showing a similar-to-random behavior. The SPAM/Au-SPE devices displayed linear responses to Myo in EIS and SWV assays down to 3.5 µg/mL and 0.58 µg/mL, respectively, with detection limits of 1.5 and 0.28 µg/mL. SPAM materials also showed negligible interference from troponin T (TnT), bovine serum albumin (BSA) and urea under SWV assays, showing promising results for point-of-care applications when applied to spiked biological fluids.

Artificial antibodies for troponin T by its imprinting on the surface of multiwalled carbon nanotubes: its use as sensory surfaces.

A novel artificial antibody for troponin T (TnT) was synthesized by molecular imprint (MI) on the surface of multiwalled carbon nanotubes (MWCNT). This was done by attaching TnT to the MWCNT surface, and filling the vacant spaces by polymerizing under mild conditions acrylamide (monomer) in N,N'-methylenebisacrylamide (cross-linker) and ammonium persulphate (initiator). After removing the template, the obtained biomaterial was able to rebind TnT and discriminate it among other interfering species. Stereochemical recognition of TnT was confirmed by the non-rebinding ability displayed by non-imprinted (NI) materials, obtained by imprinting without a template. SEM and FTIR analysis confirmed the surface modification of the MWCNT. The ability of this biomaterial to rebind TnT was confirmed by including it as electroactive compound in a PVC/plasticizer mixture coating a wire of silver, gold or titanium. Anionic slopes of 50 mV decade(-1) were obtained for the gold wire coated with MI-based membranes dipped in HEPES buffer of pH 7. The limit of detection was 0.16 µg mL(-1). Neither the NI-MWCNT nor the MWCNT showed the ability to recognize the template. Good selectivity was observed against creatinine, sucrose, fructose, myoglobin, sodium glutamate, thiamine and urea. The sensor was tested successfully on serum samples. It is expected that this work opens new horizons on the design of new artificial antibodies for complex protein structures.

Myoglobin-biomimetic electroactive materials made by surface molecular imprinting on silica beads and their use as ionophores in polymeric membranes for potentiometric transduction.

Myoglobin (Mb) is among the cardiac biomarkers playing a major role in urgent diagnosis of cardiovascular diseases. Its monitoring in point-of-care is therefore fundamental. Pursuing this goal, a novel biomimetic ionophore for the potentiometric transduction of Mb is presented. It was synthesized by surface molecular imprinting (SMI) with the purpose of developing highly efficient sensor layers for near-stereochemical recognition of Mb. The template (Mb) was imprinted on a silane surface that was covalently attached to silica beads by means of self-assembled monolayers. First the silica was modified with an external layer of aldehyde groups. Then, Mb was attached by reaction with its amine groups (on the external surface) and subsequent formation of imine bonds. The vacant places surrounding Mb were filled by polymerization of the silane monomers 3-aminopropyltrimethoxysilane (APTMS) and propyltrimethoxysilane (PTMS). Finally, the template was removed by imine cleavage after treatment with oxalic acid. The results materials were finely dispersed in plasticized PVC selective membranes and used as ionophores in potentiometric transduction. The best analytical features were found in HEPES buffer of pH 4. Under this condition, the limits of detection were of 1.3 × 10(-6)mol/L for a linear response after 8.0 × 10(-7) mol/L with an anionic slope of -65.9 mV/decade. The imprinting effect was tested by preparing non-imprinted (NI) particles and employing these materials as ionophores. The resulting membranes showed no ability to detect Mb. Good selectivity was observed towards creatinine, sacarose, fructose, galactose, sodium glutamate, and alanine. The analytical application was conducted successfully and showed accurate and precise results.

Geometric morphometrics and ecological niche modelling for delimitation of near-sibling triatomine species.

Identifying morphologically similar triatomine species is key to Chagas' disease vector control and surveillance, but remains challenging when only qualitative phenotypic data are available. We investigated whether morphometric and ecological variation can provide additional criteria for species delimitation by combining geometric morphometrics and ecological niche modelling to characterize two near-sibling triatomine species, Triatoma sordida and Triatoma garciabesi (Reduviidae: Triatominae). We analysed size and shape variation in 231 wings and 123 heads from one T. garciabesi and three T. sordida populations. Predicted distribution maps (21 climatic variables, 324 vector occurrence points) were produced using the Maxent method. Multivariate analyses summarized morphological and ecological variation. Wings and heads of T. sordida were significantly larger and more elongated than those of T. garciabesi. Discriminant analyses separated the species, with a partial overlap between Argentinean populations. The predicted distribution of T. garciabesi included northwest Argentina (mainly arid Chaco), whereas that of T. sordida included northeast Argentina (humid Chaco) and the Brazilian Cerrado and Caatinga ecoregions. Clear ecological niche differences were observed, with T. garciabesi occupying colder and drier areas than T. sordida. Our results show how morphometric variation and niche divergence can be used to enhance operational criteria for the delimitation of phenotypically similar triatomine species.

[Asymptomatic Chagas disease. Electrocardiographic and echocardiographic findings]. / Chagas asintomático. Hallazgos electrocardiográficos y ecocardiográficos.

A total of 70 blood-donor volunteers were studied to determine the utility of the echocardiogram and Doppler in the diagnosis of cardiopathies in asymptomatic patients with Chagas disease. These patients came from endemic areas and had humoral positive reactions for South American Trypanosomiasis. They were checked against a control group of blood-donors with no environmental antecedents and with negative reactions. Both groups were similar in age and sex. The chagasic group showed an abnormal electrocardiogram in twelve cases (17.4%), being left anterior hemiblock the most frequent alteration found (nine cases, 62.5%). In the control group no alterations were found (p = 0.0005). The echocardiogram and Doppler were abnormal in 29 cases of the chagasic group (38.8%): alterations in ventricular relaxation were found in 8 cases (27.6%), enlargement of cavities in 9 (31%), both phenomena in 9 (31%) and alteration of parietal motility in 3 (10.3%). In the control group, 1 case presented alteration in ventricular relaxation (p = 0.000008). These results confirmed that the abnormal discoveries were related to Chagas disease. Out of 70 chagasic patients, 31 (44.29%) showed some alteration in the tests: 12 had an abnormal electrocardiogram, and of these only 2 had normal echocardiogram and Doppler, the rest showed abnormal echocardiogram and Doppler. Other 29 (of these 70 patients) showed some alteration in the echocardiogram and Doppler, and 20 of them presented a normal electrocardiogram. It can be concluded that the echocardiogram and Doppler are more accurate to detect cardiac involvement in asymptomatic chagasic patients than the electrocardiogram, showing abnormality in many cases where there are no electrocardiographic alterations. On the other hand, patients with abnormal electrocardiogram and Doppler are less frequent. Therefore, to define the undetermined period of Chagas disease echocardiogram and Doppler should be incorporated as a routine resource of diagnosis considering the high percentage of cases in which cardiac participation is detected when there is no clinic, radiologic and electrocardiographic disturbance.

Chagas asintomático. Hallazgos electrocardiográficos y ecocardiográficos. / [Asymptomatic Chagas disease. Electrocardiographic and echocardiographic findings]

A total of 70 blood-donor volunteers were studied to determine the utility of the echocardiogram and Doppler in the diagnosis of cardiopathies in asymptomatic patients with Chagas disease. These patients came from endemic areas and had humoral positive reactions for South American Trypanosomiasis. They were checked against a control group of blood-donors with no environmental antecedents and with negative reactions. Both groups were similar in age and sex. The chagasic group showed an abnormal electrocardiogram in twelve cases (17.4

), being left anterior hemiblock the most frequent alteration found (nine cases, 62.5

). In the control group no alterations were found (p = 0.0005). The echocardiogram and Doppler were abnormal in 29 cases of the chagasic group (38.8

): alterations in ventricular relaxation were found in 8 cases (27.6

), enlargement of cavities in 9 (31

), both phenomena in 9 (31

) and alteration of parietal motility in 3 (10.3

). In the control group, 1 case presented alteration in ventricular relaxation (p = 0.000008). These results confirmed that the abnormal discoveries were related to Chagas disease. Out of 70 chagasic patients, 31 (44.29

) showed some alteration in the tests: 12 had an abnormal electrocardiogram, and of these only 2 had normal echocardiogram and Doppler, the rest showed abnormal echocardiogram and Doppler. Other 29 (of these 70 patients) showed some alteration in the echocardiogram and Doppler, and 20 of them presented a normal electrocardiogram. It can be concluded that the echocardiogram and Doppler are more accurate to detect cardiac involvement in asymptomatic chagasic patients than the electrocardiogram, showing abnormality in many cases where there are no electrocardiographic alterations. On the other hand, patients with abnormal electrocardiogram and Doppler are less frequent. Therefore, to define the undetermined period of Chagas disease echocardiogram and Doppler should be incorporated as a routine resource of diagnosis considering the high percentage of cases in which cardiac participation is detected when there is no clinic, radiologic and electrocardiographic disturbance.

[Malignant mesothelioma of the pericardium]. / Mesotelioma maligno del pericardio.

Malignant mesothelioma is a tumor which occurs in one out of every 4,000 patients autopsied for malignant neoplasia. Pericardial location is the least frequently encountered, accounting for less than 2% of the total cardiac tumors. We are presenting here a patient in whom the tumor resulted in a syndrome of cardiac tamponade. It could not be diagnosed in the living patient in spite of having performed a subxiphoideal pericardic biopsy. The patient died suddenly, and the tumor was found during autopsy, infiltrating the right atrium and protruding into the cavity, involving the right coronary artery. This latter situation could have been responsible for the patient's death. Clinical and pathological findings are compared with those of 30 cases found in recent literature.

Mesotelioma maligno del pericardio / Malignant mesothelioma of the pericardium

El mesotelioma maligno es un tumor que se presenta en relación 1: 4000 pacientes autopsiados por neoplasias malignas. La localización pericárdica es la menos frecuente, constituyendo menos del 2 por ciento del total de tumores cardíacos. Se presenta un caso en el que el tumor produjo un síndrome de taponamiento cardíaco, sin ser diagnosticado en vida a pesar de efectuarse una biopsia pericárdica subxifoidea. El paciente murió bruscamente, halládose en la autopsia dicho tumor infiltrando la aurícula derecha y haciendo protusión en la cavidad, englobando la arteria coronaria derecha. Esto último podría ser responsable de la muerte. Se comparan los hallazgos clínicos y patológicos con 30 casos extraídos de la literatura reciente

Mesotelioma maligno del pericardio. / [Malignant mesothelioma of the pericardium]

Malignant mesothelioma is a tumor which occurs in one out of every 4,000 patients autopsied for malignant neoplasia. Pericardial location is the least frequently encountered, accounting for less than 2

of the total cardiac tumors. We are presenting here a patient in whom the tumor resulted in a syndrome of cardiac tamponade. It could not be diagnosed in the living patient in spite of having performed a subxiphoideal pericardic biopsy. The patient died suddenly, and the tumor was found during autopsy, infiltrating the right atrium and protruding into the cavity, involving the right coronary artery. This latter situation could have been responsible for the patients death. Clinical and pathological findings are compared with those of 30 cases found in recent literature.

Mesotelioma maligno del pericardio / Malignant mesothelioma of the pericardium

El mesotelioma maligno es un tumor que se presenta en relación 1: 4000 pacientes autopsiados por neoplasias malignas. La localización pericárdica es la menos frecuente, constituyendo menos del 2 por ciento del total de tumores cardíacos. Se presenta un caso en el que el tumor produjo un síndrome de taponamiento cardíaco, sin ser diagnosticado en vida a pesar de efectuarse una biopsia pericárdica subxifoidea. El paciente murió bruscamente, halládose en la autopsia dicho tumor infiltrando la aurícula derecha y haciendo protusión en la cavidad, englobando la arteria coronaria derecha. Esto último podría ser responsable de la muerte. Se comparan los hallazgos clínicos y patológicos con 30 casos extraídos de la literatura reciente (AU)