globin chain
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2021 ◽  
Vol 12 (1) ◽  
pp. 396-400
Author(s):  
Ayesha Shahid ◽  
Jan Peerzada Fawad ullah

Fetal hemoglobin is the main hemoglobin during gestation period. But this globin chain is replaced and is taken over by adult hemoglobin. Sometimes this switch from fetal to adult fails to occur leading to production of fetal hemoglobin as in case of sickle cell anemia. It is also observed that fetal hemoglobin expression is also seen under malignant condition. In malignancy the spleen, liver as well as gut acquire its ability to produce fetal hemoglobin. Certain HbF cells inducing factor such as stem cell growth factor and interleukin -3 also promote HbF erythropoiesis. HbF cells are indicated as a biomarker of tumour cells implicated in many carcinomas observed by immunohisto chemical investigations.


2021 ◽  
Vol 20 (3) ◽  
pp. 102-107
Author(s):  
M. V. Krasilnikova ◽  
N. A. Karamyan ◽  
E. A. Litvin ◽  
S. G. Mann

Hb Lepore, as the result of fusion of the b- and d-globin genes, leads to decreased amount of non-a-globin chains availability for hemoglobin formation. Hb Lepore, up to now, was not identified among Russian patients. We provide clinical and laboratory information on Hb Lepore Boston–Washington in two cases, one of them familial. A small amount of abnormal Hb was detected by capillary electrophoresis, an abnormal globin chain was shown by HPLC, and the final diagnosis of Hb Lepore Boston– Washington was made by molecular biological analysis of globin genes. Peripheral blood for all affected people revealed RBC’s hypochromia microcytosis and normal Hb concentration. The parents of the patients agreed to use the information, including photos of children, in scientific research and publications.


2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Alexander P. Morton ◽  
Jamie B. Hadley ◽  
Arsen Ghasabyan ◽  
Marguerite R. Kelher ◽  
Ernest E. Moore ◽  
...  

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Androulla N. Miliotou ◽  
Dionysia Papagiannopoulou ◽  
Efthymia Vlachaki ◽  
Martina Samiotaki ◽  
Dimitra Laspa ◽  
...  

Abstract Background α-Thalassemia, a congenital hemoglobinopathy, is characterized by deficiency and/or reduced levels of α-globin chains in serious forms of α-thalassemia (HbH disease/Hb Bart’s). This research work deals with a Protein Replacement Therapy approach in order to manage α-thalassemia manifestations, caused by the excess of β-globin chain into HbH RBCs. The main goal was to produce the recombinant human α-globin chain in fusion with TAT, a Protein Transduction Domain, to ex vivo deliver it into HbH patients RBCs, to replace the endogenous missing α-globin chain. Results Cloning of the α-globin coding sequence, fused to the nucleotide sequence of TAT peptide was conducted and the human recombinant fusion proteins, 10xHis-XaSITE-α-globin-HA and 10xHis-XaSITE-TAT-α-globin-HA were produced. The ability of human recombinant 10xHis-XaSITE-α-globin-HA to interact in vitro with the previously produced 10xHis-XaSITE-TAT-β-globin-HA and form α-/β-globin heterodimers, was assessed and confirmed by size exclusion chromatography. The recombinant 10xHis-XaSITE-TAT-α-globin-HA was successfully delivered into human proerythroid K-562 cells, during the preliminary transduction evaluation experiments. Finally, the recombinant, TAT-fused α-globin was successfully transduced into RBCs, derived from HbH patients and reduced the formation of HbH-Inclusion Bodies, known to contain harmful β4-globin chain tetramers. Conclusions Our data confirm the successful ex vivo transduction of recombinant α-globin chains in HbH RBCs to replace the missing a-globin chain and reduce the HbH-inclusion bodies, seen in α-thalassemias. These findings broaden the possibility of applying a Protein Replacement Therapy approach to module sever forms of α-thalassemia, using recombinant α-globin chains, through PTD technology.


Author(s):  
Nazish Sana ◽  
Muhammad Shariq Shaikh ◽  
Admin

Madam, Adult haemoglobin (Hb) comprises of 2 alpha and 2 beta-globin chains, each having a haem molecule attached. In healthy individuals, around 95-98% HbA (?2?2) and 2–3.5% of Hb A2 (?2?2) are present. The genetic defect of globin chain in which valine is replaced for glutamic acid at position 6 of ? globin chain results in sickle haemoglobin (HbS). Homozygous genetic defect (?S?S) results in a symptomatic disease called 'sickle cell anaemia' whereas, heterozygous (??S) state is asymptomatic and commonly called as "sickle cell trait' [1]. On deoxygenation and dehydration, HbS undergoes irreversible polymerization causing deleterious effects in vivo [2]. Around 3.2 million people have sickle-cell disease worldwide, with about 80% cases in Africa. About 0.5 to 1 per cent of the Pakistani population carries HbS3. Currently, high-performance liquid chromatography (HPLC) is the preferred method in which HbS elutes at retention time ranging in between 4.1 to 4.7 minutes. Several other variant haemoglobins cause interference by co-eluting at same retention time include HbA2, Hb Q-Thailand, Hb Manitoba, Hb Russ, Hb Stanlivelly-II, HbE- Saskatoon, Hb Montgomery and many more[4]. Therefore, it is difficult to identify and differentiate HbS precisely from interfering variant haemoglobins for proper diagnosis and future genetic counselling of patients. The definitive test for this purpose is molecular detection of underlying mutation either by polymerase chain reaction (PCR) or sequencing of the beta-globin gene. Molecular tests, however, are expensive and require expertise. Therefore, these tests are not widely available in Pakistan and other resource constraint countries. World's leading quality assurance organizations such as College of American Pathologists (CAP) recommend that all cases found HbS positive in the primary screening should be confirmed by secondary testing [5], this can easily be achieved by sickling test. In the sickling test, the sample is combined with reducing agent (Sodium Met bisulfate) resulting in red cell hypoxia. Cells with HbS change to sickle shape from their normal biconcave shape, diagnosed by microscopic examination along with controls. This cost-effective and readily available technique helps to differentiate HbS from other variants. Therefore, every laboratory should confirm the presence of HbS by sickling test, and the government should ensure the availability of molecular tests at the mass level at a reduced cost supported by the efficient health insurance system. The impact of these strategies will provide accurate and timely diagnosis, Continuous...  


2020 ◽  
Author(s):  
C.L. Faust ◽  
F. Rangkuti ◽  
S. G. Preston ◽  
A. Boyd ◽  
P. Flammer ◽  
...  

AbstractHuman haemoglobin variants, such as sickle, confer protection against death from malaria; consequently, frequencies of such variants are often greatly elevated in humans from malaria endemic regions. Among non-human primates, the long-tailed macaque, Macaca fascicularis, also displays substantial haemoglobin variation. Almost all M. fascicularis haemoglobin variation is in the alpha globin chain, encoded by two linked genes: HBA1 and HBA2. We demonstrate that alpha globin variation in M. fascicularis correlates with the strength of malaria selection. We identify a range of missense mutations in M. fascicularis alpha globin and demonstrate that some of these exhibit a striking HBA1 or HBA2 specificity, a pattern consistent with computational simulations of selection on genes exhibiting copy number variation. We propose that M. fascicularis accumulated amino acid substitutions in its alpha globin genes under malaria selection, in a process that closely mirrors, but does not entirely converge with, human malaria adaptation.


2020 ◽  
Vol 8 (10) ◽  
pp. 4876-4880
Author(s):  
Kalpana Ladvikar

Thalassemia is the most common genetic disorder resulting from abnormality of Globin chain. It is the worldwide problem of today’s era and until no answer to any medical science. It is the challenging disorder for the scientist. The nature of the disease is genetic regarding this so many literatures available in the modern science but in Ayurveda has no answer for this disease. To add the new concept of disease Thalassemia (Anukta Vyadhi In Ayurveda), aim of study is to understand the unknown disease, the concept of Beeja, Beejabhaga and Beejabhagavayava should be clear because of its genetic nature of thalassemia. Charaka mentioned Aptopadesha method of examination, we can acquire knowledge as described by wise men, or Apta, use to understand a disease:


2020 ◽  
Vol 477 (19) ◽  
pp. 3839-3850
Author(s):  
Chandrasekhar Natarajan ◽  
Anthony V. Signore ◽  
Vikas Kumar ◽  
Roy E. Weber ◽  
Angela Fago ◽  
...  

In vertebrate haemoglobin (Hb), the NH2-terminal residues of the α- and β-chain subunits are thought to play an important role in the allosteric binding of protons (Bohr effect), CO2 (as carbamino derivatives), chloride ions, and organic phosphates. Accordingly, acetylation of the α- and/or β-chain NH2-termini may have significant effects on the oxygenation properties of Hb. Here we investigate the effect of NH2-terminal acetylation by using a newly developed expression plasmid system that enables us to compare recombinantly expressed Hbs that are structurally identical except for the presence or absence of NH2-terminal acetyl groups. Experiments with native and recombinant Hbs of representative vertebrates reveal that NH2-terminal acetylation does not impair the Bohr effect, nor does it significantly diminish responsiveness to allosteric cofactors, such as chloride ions or organic phosphates. These results suggest that observed variation in the oxygenation properties of vertebrate Hbs is principally explained by amino acid divergence in the constituent globin chains rather than post-translational modifications of the globin chain NH2-termini.


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