Retrospective study of allometric relationship between heart rate, electrocardiographic parameters and bodyweight in dogs / Estudo retrospectivo da relação alométrica entre frequência cardíaca, parâmetros eletrocardiográficos e peso corporal em cães

The allometric relationship between bodyweight (BW) and heart rate (HR) has been described as inversely proportional in domestic species, but that has been refuted. The relationship between HR and electrocardiographic variables is described in literature. However, studies about the variation and influence of factors on the hemodynamic and electrocardiographic parameters in dogs are not abundant. As the metabolic rate is defined as the production and dissipation of heat by the body surface area (BSA) in m², it is essential to define that relationship. A retrospective study was conducted to analyze the correlation between HR, ECG parameters and BW in dogs. One thousand electrocardiographic tracings were analyzed in addition to the ECG parameters and clinical data such as gender, age and bodyweight. The determination of BSA was performed as follows: BSA (m2) = (10.1 x bodyweight 0.67) X 10-4. When the unified groups were analyzed, there was a negative but weak correlation (r= -0.14, P< 0.0001) between bodyweight and HR. There were differences between weight groups regarding electrocardiographic variables. There is no allometric relationship between BW and HR in dogs. Weight was associated with changes in ECG variables.(AU)

A relação alométrica entre peso corporal (PC) e frequência cardíaca (FC) foi descrita como inversamente proporcional em animais domésticos, mas isso tem sido refutado. A relação entre FC e variáveis eletrocardiográficas é descrita na literatura. No entanto, estudos sobre a variação e a influência de fatores nos parâmetros hemodinâmicos e eletrocardiográficos em cães não são abundantes. A taxa metabólica é definida como a produção e dissipação de calor pela área de superfície corporal (ASC), de modo que é essencial definir essa relação. Foi realizado um estudo retrospectivo para analisar a correlação entre FC, parâmetros eletrocardiográficos (ECG) e peso corporal em cães. Foram analisados mil traçados eletrocardiográficos, além dos parâmetros de ECG e dados clínicos, como gênero, idade e peso corporal. A determinação da ASC foi realizada da seguinte forma: ASC (m 2 ) = (10,1x peso corporal 0,67 ) x 10 -4 . Quando os grupos unificados foram analisados, houve uma correlação negativa, porém fraca (r= -0,14, P<0,0001) entre PC e FC. Houve diferenças entre os grupos de peso em relação às variáveis eletrocardiográficas. Não há relação alométrica entre PC e FC em cães. O peso foi associado a alterações nas variáveis de ECG.(AU)

Hormonal control and target genes of ftz-f1 expression in the honeybee Apis mellifera: a positive loop linking juvenile hormone, ftz-f1, and vitellogenin.

Ftz-f1 is an orphan member of the nuclear hormone receptor superfamily. A 20-hydroxyecdysone pulse allows ftz-f1 gene expression, which then regulates the activity of downstream genes involved in major developmental progression events. In honeybees, the expression of genes like vitellogenin (vg), prophenoloxidase and juvenile hormone-esterase during late pharate-adult development is known to be hormonally controlled in both queens and workers by increasing juvenile hormone (JH) titres in the presence of declining levels of ecdysteroids. Since Ftz-f1 is known for mediating intracellular JH signalling, we hypothesized that ftz-f1 could mediate JH action during the pharate-adult development of honeybees, thus controlling the expression of these genes. Here, we show that ftz-f1 has caste-specific transcription profiles during this developmental period, with a peak coinciding with the increase in JH titre, and that its expression is upregulated by JH and downregulated by ecdysteroids. RNAi-mediated knock down of ftz-f1 showed that the expression of genes essential for adult development (e.g. vg and cuticular genes) depends on ftz-f1 expression. Finally, a double-repressor hypothesis-inspired vg gene knock-down experiment suggests the existence of a positive molecular loop between JH, ftz-f1 and vg.

Defects in NADPH Oxidase Genes NOX1 and DUOX2 in Very Early Onset Inflammatory Bowel Disease.

BACKGROUND & AIMS: Defects in intestinal innate defense systems predispose patients to inflammatory bowel disease (IBD). Reactive oxygen species (ROS) generated by nicotinamide-adenine dinucleotide phosphate (NADPH) oxidases in the mucosal barrier maintain gut homeostasis and defend against pathogenic attack. We hypothesized that molecular genetic defects in intestinal NADPH oxidases might be present in children with IBD. METHODS: After targeted exome sequencing of epithelial NADPH oxidases NOX1 and DUOX2 on 209 children with very early onset inflammatory bowel disease (VEOIBD), the identified mutations were validated using Sanger Sequencing. A structural analysis of NOX1 and DUOX2 variants was performed by homology in silico modeling. The functional characterization included ROS generation in model cell lines and in in vivo transduced murine crypts, protein expression, intracellular localization, and cell-based infection studies with the enteric pathogens Campylobacter jejuni and enteropathogenic Escherichia coli. RESULTS: We identified missense mutations in NOX1 (c.988G>A, p.Pro330Ser; c.967G>A, p.Asp360Asn) and DUOX2 (c.4474G>A, p.Arg1211Cys; c.3631C>T, p.Arg1492Cys) in 5 of 209 VEOIBD patients. The NOX1 p.Asp360Asn variant was replicated in a male Ashkenazi Jewish ulcerative colitis cohort. All NOX1 and DUOX2 variants showed reduced ROS production compared with wild-type enzymes. Despite appropriate cellular localization and comparable pathogen-stimulated translocation of altered oxidases, cells harboring NOX1 or DUOX2 variants had defective host resistance to infection with C. jejuni. CONCLUSIONS: This study identifies the first inactivating missense variants in NOX1 and DUOX2 associated with VEOIBD. Defective ROS production from intestinal epithelial cells constitutes a risk factor for developing VEOIBD.

Prevalence of primary drug resistance-associated mutations among HIV type 1 vertically Infected children in Belo Horizonte, Brazil.

In the past few years there has been increasing concern about the transmission of drug-resistant HIV. This study aimed to describe the frequency of primary mutations associated with HIV-1 drug resistance and the prevalence of genetic HIV subtypes in a population of vertically infected children before the initiation of HAART. At the time of genotypic testing, the median age was 6.0 years (IQR 25-75%: 3.8-9.2) and the median age at admission was 3.84 years (IQR 25-75%: 1.23-6.11). Antepartum maternal ARV exposure for PMTCT occurred for three (7.3%) mothers. According to the WHO criteria, primary ARV resistance mutations were detected in four out of 41 (9.8%) children. Subtype B was the most prevalent (63.4%). The relatively high prevalence of primary HIV-1 DRMs in this cohort of perinatally infected children in Brazil supports the local recommendation to perform resistance testing in all newly diagnosed children, regardless of age at diagnosis and antenatal ARV exposure.

Drug resistance mutation profile and accumulation kinetics in human immunodeficiency virus-positive individuals infected with subtypes B and F failing highly active antiretroviral therapy are influenced by different viral codon usage patterns.

The major human immunodeficiency virus type 1 subtype circulating in Brazil is B, followed by F and C. We have genotyped 882 samples from Brazilian patients for whom highly active antiretroviral therapy failed, and we found subtype B and the unique recombinant B/F1 forms circulating. Due to codon usage variation, there is a significantly lower incidence of the substitutions L210W, Q151M, and F116Y in subtype F1 isolates than in the subtype B counterparts.

False I50V resistance readings of HIV isolates: co-amplification of NASBA HIV-1 RNA QT internal calibrators and HIV-1 patient isolates may lead to a false I50V mutation resistance reading in genotypic tests.

The I50V protease inhibitor (PI) resistance mutation was found in 87.4% of protease gene fragments sequenced from 199 nucleic acid isolates extracted using an NASBA virus load assay, performed between 1997 and 2001 in Brazil. This mutation is an amprenavir-related mutation, and at that particular time this PI was seldom used in Brazil. This mutation was found both in patients with and without therapeutic success. Q calibrators showed the PI resistance mutation I50V when directly amplified and sequenced from the 423-bp PCR product targeting protease gene. The majority of the patients' samples had a mixture of I50I and I50V; however, this artifact was nor seen when a 989-bp PCR product was used. These results show that RNA extracted using virus load kits need to be critically evaluated before being used in home-brew genotypic tests.

Expression at mRNA level of cytokines and A238L gene in porcine blood-derived macrophages infected in vitro with African swine fever virus (ASFV) isolates of different virulence.

Porcine macrophage cultures were infected with two ASFV isolates of variable virulence and mRNA levels of several relevant macrophage-derived cytokines were quantified by real time PCR. At six hours post infection, a clear enhancement of mRNA expression of TNFalpha, IL6, IL12 and IL15 was observed in macrophages infected with the low virulent ASFV/NH/P68 (NHV) when compared to those infected with the highly virulent ASFV/L60 (L60). The sequence of the A238L gene homologue to the cellular IkappaB was found identical in both viral isolates and its expression at mRNA level was higher in macrophages infected with NHV when compared to macrophages infected with L60. Furthermore our results suggest a negative correlation between the mRNA expression of A238L gene and the mRNA expression of the above mentioned cytokines (with the exception of IL10) in L60 infected macrophages in opposition to the positive correlation (with exception of the IL1) suggested in NHV infection. Overall, our data strongly emphasize that virulence of ASFV isolates may depend on their capacity to regulate the expression of macrophage-derived cytokines relevant for the development of host protective responses by yet unknown mechanisms triggered by the virus at early stages of the cellular infection.

The ability of Bipolaris sorokiniana to modify geraniol and (-)-alpha-bisabolol as exogenous substrates.

The biocatalytic potential of Bipolaris sorokiniana was investigated in its ability to modify the monoterpene geraniol and the sesquiterpene alpha-bisabolol as exogenous substrates, using phosphate buffer as reaction medium. The cultures showed a promising oxidative profile, with conversion of geraniol to 6-methyl-5-hepten-2-one (74.9% yield) in a 5-day incubation and alpha-bisabolol to bisabolol oxide B (84.2% yield), in a 7-day incubation.

Blood group antigen profile predicted by molecular biology-use of real-time polymerase chain reaction to genotype important KEL, JK,RHD, and RHCE alleles.

The most clinically important blood group systems in transfusion medicine, excluding the ABO system, are the RH, Kell, and Kidd systems. Alloantibodies to antigens of these systems may be produced following blood transfusion or during pregnancy and can result in serious hemolytic transfusion reactions and hemolytic disease of the newborn. We developed rapid and robust techniques for RHD, RHCE, KEL, and JK genotyping with the use of a real-time polymerase chain reaction instrument. Two fluorescence-based methods for the detection of amplification products were used: for KEL1/KEL2, JK1/JK2, and RHE/RHe (exon 5) we used the hybridization probes protocol; for RHC/RHc the analysis was done in sequences of exon 1 for RHC and exon 2 for RHc; and for RHD, analysis was done in sequences of intron 4, exon 7, and exon 4 pseudogene using the SYBR Green I protocol. The genotyping tests were validated with samples from 85 Caucasian Portuguese and 15 Black European blood donors. Complete phenotype-genotype correlations were obtained. The potential use of the presented methods can be predicted in clinical transfusion medicine, allowing appropriate monitoring, early intervention, and improved care. When blood group genotyping techniques are necessary, this methodology is highly competitive for a routine laboratory.

[Coronary angioplasty. Initial experience of the Santa Cruz Hospital]. / Angioplastia coronária. Experiência inicial do Hospital de Santa Cruz.

The initial experience with percutaneous transluminal coronary angioplasty (PTCA) at Santa Cruz Hospital is presented. Between May and November 1984, ten patients with single significant (> 75%) coronary artery obstructions, 8 of the left anterior descending (LAD), 1 of the circumflex (Cx) and one of the right coronary artery (RCA), underwent coronary angioplasty using Gruentzig's technique and steerable catheters. Five patients were cases of chronic stable angina and 5 patients were cases of unstable angina, one of them of acute coronary insufficiency previously treated with intracoronary streptokinase. In every case was possible to cross the lesions which were proximal in 9 cases (7 of the LAD, 1 of the Cx and 1 of the RCA) and distal (LAD) in one case. Primary failure to dilate was seen in 2 cases of unstable angina due to pain and reversible ECG changes. In only 1 case there was occlusion at 9 hours after angioplasty which required emergency bypass operation. Although with a short follow-up, six patients are well and free of symptoms and in only 1 case there was recurrence of angina at four and a half months after PTCA. These results which represent the beginning of the learning curve are considered satisfactory and rewarding.

Rapid genotyping of the major alleles at the Duffy (FY) blood group locus using real-time fluorescence polymerase chain reaction.

The Duffy blood group system has clinical importance due to involvement in transfusion reactions and hemolytic disease of the newborn. Recently, the molecular basis of the two alleles, FY*A and FY*B (125G>A), and the mutation situated in the promoter region of the FY gene (-33T>C), have been elucidated. In order to develop an accurate, easy, and rapid genotyping method, we describe a procedure using the LightCycler. Samples from 53 Caucasian Portuguese blood donors and 7 black, healthy, European individuals were phenotyped with commercial antisera. DNA was extracted from blood samples and the relevant sequences were amplified with the same cycling conditions, using real-time polymerase chain reaction. The melting point of the FY*A allele was 63 degrees C and of the FY*B allele, 55 degrees C. The allele without mutation at the promoter region had a melting point at 64 degrees C and the FY*B silent allele at 58 degrees C. The results in Caucasian individuals were similar to those found in European and American populations. When FY genotyping techniques are necessary, the methodology described is preferable to conventional methods as it is reliable, high speed, and uses small volumes, providing a highly competitive technology for use by a routine laboratory.

Heteroduplex mobility assay for rapid, sensitive and specific detection of mycobacteria.

We report an improved method for the detection and identification of mycobacteria using PCR and the heteroduplex mobility shift assay (HMA). The HMA for detection of mycobacteria was based on the microheterogeneity within the DNA coding sequences for 16S rRNA. A remarkable shift between single-stranded, heteroduplex and homoduplex bands in PAGE was observed among the Mycobacterium spp. tested. The Mycobacteria HMA (MHMA) of amplified PCR products from mycobacteria DNA coding for 16S rDNA derived from culture showed a specific heteroduplexes formed among different Mycobacterium species. Other bacterium species were distinguished from Mycobaterium due to slow migrating heteroduplexes mobility bands observed when M. bovis (BCG), M. avium, or M. fortuitum were used as a standard. The specific heteroduplexes were detected when as little as 1 etag of DNA template was used, although better results were obtained with 5 etag and when PCR products of sample test and mycobacterium standard were mixed at a ratio of 1.8. To correctly evaluate the feasibility of using MHMA to detect and identify mycobacteria, 15 clinical sample patients were tested. All MTB-positive clinical samples were identified by MHMA as well as the negative samples. In addition, MHMA will, in principle, be applicable to the detection and classification of any microorganism showing differences within the 16S rRNA as well as to the identification of new and unrecognized bacterial species.

[The diagnostic and prognostic value of the 12-lead electrocardiogram in assessing the severity of coronary disease in the acute phase of an acute myocardial infarct]. / Valor diagnóstico e prognóstico do electrocardiograma de doze derivações, na avaliação da gravidade da doença coronária na fase aguda do enfarte agudo do miocárdio.

UNLABELLED: The conventional twelve-lead electrocardiogram (ECG) still is the cheapest, most used and absolutely essential diagnostic method for the acute phase of myocardial infarction (MI) allowing risk stratification and coronary prognostic evaluation in this phase mainly by the localization of the ST segment depression and/or T wave inversion (ST/T changes) not related to the infarct area in Q-Wave MI or at any localization in case of non-Q wave MI. The etiology and pathophysiology of these ST/T changes in the setting of MI has been controversial. With the objective of determining ECG prognostic and diagnostic value, 70 patients (Pts) (59 men and 11 women, mean age 58 + 13) admitted in the acute phase of MI were studied with revision of acute phase ECG ST/T changes. All patients underwent coronary angiography and ventriculography at the moment of hospital discharge. Patients were divided into two classifications: A) MI localization: A1--Q-wave MI (anterior--20 pts, inferior--29 pts, lateral--1 pt); A2--non-Q wave--20 pts. B) Evidence of ST/T changes outside the infarct area in Q wave MI or at any localization in non-Q wave MI (group B1--with ST/T changes, group B2--without ST/T changes). We correlated the angiographically documented coronary artery disease in groups with ST/T changes and their localization. RESULTS: A1) Anterior MI group: in the 6 pts (30%) with "opposite" (inferior) ST/T changes, right coronary artery (RCA) disease was documented in 5 and in the other 14 patients the RCA did not show significant lesions. Inferior MI group: in the 24 Pts (83%) with "opposite" (precordial) ST/T changes. 23 of them had angiographic correlation (left anterior descending (LAD) and/or circumflex (CX) artery disease). Lateral MI group: one Pt with anterior wall ST/T changes and LAD and CX disease. A2) Non-Q wave group: in 13 pts (87%) the diseased vessels were correlated with the site of ST/T changes. B1) Q-Wave AMI: left main and 3-vessel disease in 2 pts, 3-vessel disease in 17 pts, 2-vessel disease in 9 pts, 1-vessel disease in 2 pts and non-significant disease in one pt. Non-Q wave MI: left main and 3-vessel disease in 1 pt, 3-vessel disease in 7 patients, 2-vessel disease in 3 pts and 1-vessel disease in 4 pts. B2) non-Q Wave MI: 3-vessel disease in 5 pts, 2-vessel disease in 7 pts, 1-vessel disease in 6 pts and non-significant disease in 1 pt. Non-Q wave MI: 2-vessel disease in 2 pts and non-significant disease in 1 pt. IN CONCLUSION: When pts were divided according to MI localization, a correlation was found between the ST/T changes outside the infarct area with CAD in 91% of Pts in the Q-Wave infarction group, with more significance in inferior and lateral MI. In the non-Q wave group, we found correlation between the a coronary lesions and the localization of ST/T changes in 87% of the pts. The pt group with ST/T changes presented, when compared with the pt group without these changes, evidence of more severe coronary artery disease (CAD): 3 vessels or left main with 3 vessel disease. However, only in the Q-Wave infarction group was a statistically significant difference found between the group with ST/T changes compared to the group without these changes, concerning to the existence of more severe coronary disease.

[Myocardial viability. Concept, physiopathology. Methods and diagnostic value]. / Viabilidade miocárdica. Conceito, fisiopatologia, Métodos e valor diagnóstico.

The purpose of this study is to describe the concept and physiopathology of myocardial viability to provide rational use of diagnostic methodologies and their value. Great relevance has been given to the diagnosis of myocardial viability since it was published in 1982, because of the consequences of therapeutic decisions and prognostic evaluation on the patient's quality of life. The cost/benefit values of these methodologies must be adequate in clinical terms and carefully assessed.

Tumor-like lesion due to Chagas' disease in a patient with lymphocytic leukemia.

A 73 year-old white male, living in the interior of the state of Mato Grosso do Sul, in central Brazil, after an initial diagnosis of sinusitis was transferred to the neurology service with a 3-day evolution of intracranial hypertension. Exams showed lymphocytic leukemia and a tumor-like lesion, either an expanding inflammatory process such as an abscess or a neoplasm. Treatment with Ceftriaxone and Decadron was started and intracranial hypertension was controlled. Methotrexate was injected on the occasion of the next puncture considering a possible leukemia infiltration. Flagellate forms of T. cruzi were observed in the CSF and treatment with Benznidazole was started. After 4 days the CSF presented fractionated forms of trypomastigotes. The protein level was 27%. Signs of intracranial hypertension ceased. Tomography and magnetic resonance images showed an important reduction of the tumor-like lesion. The clinical condition of the patient improved.