Hemoglobin genotype has minimal influence on the physiological response of juvenile atlantic cod (Gadus morhua) to environmental challenges

Hemoglobin (Hb) polymorphism in cod is associated with temperature‐related differences in biogeographical distribution, and several authors have suggested that functional characteristics of the various hemoglobin isoforms (HbIs) directly influence phenotypic traits such as growth rate. However, no study has directly examined whether Hb genotype translates into physiological differences at the whole animal level. Thus, we generated a family of juvenile Atlantic cod consisting of all three main Hb genotypes (HbI‐1/1, HbI‐2/2, and HbI‐1/2) by crossing a single pair of heterozygous parents, and we compared their metabolic and cortisol responses to an acute thermal challenge (10°C to their critical thermal maximum [CTM] or 22°C, respectively) and tolerance of graded hypoxia. There were no differences in routine metabolism (at 10°C), maximum metabolic rate, metabolic scope, CTM (overall mean 22.9° ± 0.2°C), or resting and poststress plasma cortisol levels among Hb genotypes. Further, although the HbI‐1/1 fish grew more (by 15%–30% during the first 9 mo) when reared at 10° ± 1°C and had a slightly enhanced hypoxia tolerance at 10°C (e.g., the critical O2 levels for HbI‐1/1, HbI‐2/2, and HbI‐1/2 cod were 35.56% ± 1.24%, and 40.20% ± 1.99% air saturation, respectively), these results are contradictory to expectations based on HbI functional properties. Thus, our findings (1) do not support previous assumptions that growth rate differences among cod Hb genotypes result from a more efficient use of the oxygen supply—that is, reduced standard metabolic rates and/or increased metabolic capacity—and (2) suggest that in juvenile cod, there is no selective advantage to having a particular Hb genotype with regards to the capacity to withstand ecologically relevant environmental challenges.

HbA1c: chasing numbers or considering context?

Glycated haemoglobin (HbA_1c) reflects the average blood glucose level in the three months preceding the test. Changes in consecutive HbA_1c tests indicate deteriorating, or improved, glycaemic control. HbA_1c is considered to be the "gold standard" measure of blood glucose control and is often used as the basis for prescribing choices and other care decisions. A number of factors can affect the accuracy of the HbA_1c result, for example, the life span of red blood cells, assay methods and clinicians' awareness of possible interfering factors. The aim of this article is to outline how HbA_1c is used as a diagnostic test, how it is used to monitor glycaemic control and how it can guide management decisions. It is also important to emphasise the importance of considering HbA_1c in the context of the individual rather than as an isolated number.

Blood hemoglobin content and metabolic performance of Arctic Tern chicks Sterna paradisaea

This study was designed to determine whether the development of an increased aerobic capacity (increased potential for oxygen uptake) during the initial growth stages of hatchlings is associated with an increase in blood hemoglobin content. We measured the resting (at thermoneutrality) and maximum (cold induced)b oxygen uptake of Arctic Tern chicks from 0 to 9 days of age. In addition, blood hemoglobin content and hematocrit were measured. The results show that in spite of a marked increase in both resting and maximum oxygen uptake, indicating increased metabolic performance, there was a slight decrease in blood hemoglobin content during the first few days of development. A residual analysis, made to eliminate the effect of age, showed that blood hemoglobin content of individual chicks, blood hemoglobin contents is not a limiting factor for oxygen uptake by Arctic Tern chicks.

BacHbpred: support vector machine methods for the prediction of bacterial hemoglobin-like proteins

The recent upsurge in microbial genome data has revealed that hemoglobin-like (HbL) proteins may be widely distributed among bacteria and that some organisms may carry more than one HbL encoding gene. However, the discovery of HbL proteins has been limited to a small number of bacteria only. This study describes the prediction of HbL proteins and their domain classification using a machine learning approach. Support vector machine (SVM) models were developed for predicting HbL proteins based upon amino acid composition (AC), dipeptide composition (DC), hybrid method (AC + DC), and position specific scoring matrix (PSSM). In addition, we introduce for the first time a new prediction method based on max to min amino acid residue (MM) profiles. The average accuracy, standard deviation (SD), false positive rate (FPR), confusion matrix, and receiver operating characteristic (ROC) were analyzed. We also compared the performance of our proposed models in homology detection databases. The performance of the different approaches was estimated using fivefold cross-validation techniques. Prediction accuracy was further investigated through confusion matrix and ROC curve analysis. All experimental results indicate that the proposed BacHbpred can be a perspective predictor for determination of HbL related proteins. BacHbpred, a web tool, has been developed for HbL prediction.

On the temperature stability of extracellular hemoglobin of Glossoscolex paulistus, at different oxidation states: SAXS and DLS studies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sir2-Related Protein 1 from Leishmania amazonensis is a glycosylated NAD(+)-dependent deacetylase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Alternative method of smearing samples on slides facilitate visualization of hemoglobin H inclusion bodies in alpha thalassemia

Nas talassemias alfa, a HbH pode ser detectada, nos eritrócitos do sangue periférico como inclusões celulares quando coradas com azul crezil brillante. Este teste simples é útil para o diagnóstico de talassemia alfa, no entanto, a identificação dos corpos de inclusão de HbH é um processo laborioso e os resultados são altamente dependentes do observador. No intuito de melhorar a identificação das inclusões, foi testado um método alternativo para espalhar as amostras nas lâminas. Amostras de sangue foram espalhadas nas lâminas usando-se o método clássico e o método alternativo. O método alternativo permitiu uma melhor identificação das inclusões de HbH do que o método clássico. Nossos resultados mostraram que o método alternativo é uma opção útil para a pesquisa dos corpúsculos de inclusão de HbH naquelas amostras onde o método clássico não o permite.

Hemoglobin Kansas found by electrophoretic diagnosis in Brazil

Hemoglobinas variantes com afinidade anormal ao oxigênio têm sido encontradas em várias partes do mundo. Pela sua afinidade ao oxigênio, estas hemoglobinas variantes têm sido classificadas e 15 variantes com baixa afinidade relatadas. Numerosas hemoglobinas mutantes com afinidade anormal têm também sido relatadas, mas somente poucos casos de Hemoglobina Kansas. Os casos são de pacientes procedentes do Japão, ou de famílias com descendentes japoneses. Neste relato descrevemos um paciente com manifestações de cianose que teve o seu diagnóstico confirmado através da eletroforese.

Characterization and oxygen binding properties of des-Arg human hemoglobin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Knowledge extraction using visualization of hemoglobin parameters to identify thalassemia

The analysis of large amounts of data is better performed by humans when represented in a graphical format. Therefore, a new research area called the Visual Data Mining is being developed endeavoring to use the number crunching power of computers to prepare data for visualization, allied to the ability of humans to interpret data presented graphically.This work presents the results of applying a visual data mining tool, called FastMapDB to detect the behavioral pattern exhibited by a dataset of clinical information about hemoglobinopathies known as thalassemia. FastMapDB is a visual data mining tool that get tabular data stored in a relational database such as dates, numbers and texts, and by considering them as points in a multidimensional space, maps them to a three-dimensional space. The intuitive three-dimensional representation of objects enables a data analyst to see the behavior of the characteristics from abnormal forms of hemoglobin, highlighting the differences when compared to data from a group without alteration.