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Anemia, splenomegaly, and increased osmotic fragility of erythrocytes in Abyssinian and Somali cats.Journal of the American Veterinary... Nov 2000To determine clinical and clinicopathologic features of a chronic intermittent severe hemolytic anemia characterized by erythrocyte osmotic fragility in Abyssinian and...
OBJECTIVE
To determine clinical and clinicopathologic features of a chronic intermittent severe hemolytic anemia characterized by erythrocyte osmotic fragility in Abyssinian and Somali cats.
DESIGN
Case series.
ANIMALS
13 Abyssinian and 5 Somali cats.
PROCEDURES
History, pedigree information, and results of routine laboratory tests, special erythrocyte studies, and histologic evaluation of splenic and hepatic specimens were analyzed.
RESULTS
Age at which clinical signs of anemia were first apparent ranged from 6 months to 5 years. Ten cats had splenomegaly. Most often, the PCV was between 15 and 25%, but it was as low as 5% at some times. The anemia was characterized by macrocytosis and mild to moderate reticulocytosis, but no poikilocytosis. Hyperglobulinemia, lymphocytosis, mild hyperbilirubinemia, and high hepatic enzyme activities were common findings. Results of Coombs tests and tests for infectious diseases were negative. The erythrocytic osmotic fragility was high in affected cats (mean osmotic fragility, 0.66 to 0.78%), compared with healthy cats (0.48 to 0.58). No specific membrane protein abnormality, erythrocyte enzyme deficiency, or hemoglobinopathy was identified. Histologic evaluation of splenic and hepatic specimens revealed extramedullary hematopoiesis and hemosiderosis. Four of the 5 Somali cats were closely related.
CONCLUSIONS AND CLINICAL RELEVANCE
On the basis of results of pedigree analyses, the apparent breed predilection, and the exclusion of other known causes of anemia in cats, we believe that the hemolytic anemia in these cats was likely a result of a novel hereditary erythrocyte defect. A genetic predisposition to immune-mediated destruction of erythrocytes could not be ruled out.
Topics: Anemia, Hemolytic, Autoimmune; Animals; Blood Chemical Analysis; Cat Diseases; Cats; Chromatography, High Pressure Liquid; Coombs Test; Electrophoresis, Polyacrylamide Gel; Female; Hematocrit; Hemoglobins; Histocytochemistry; Liver; Male; Membrane Proteins; Microscopy, Electron; Osmotic Fragility; Pedigree; Pyruvate Kinase; Spleen; Splenomegaly
PubMed: 11128538
DOI: 10.2460/javma.2000.217.1483 -
Blood Sep 1993Hereditary pyropoikilocytosis (HPP) is a recessively inherited hemolytic anemia characterized by severe poikilocytosis and red blood cell fragmentation. HPP red blood...
Hereditary pyropoikilocytosis (HPP) is a recessively inherited hemolytic anemia characterized by severe poikilocytosis and red blood cell fragmentation. HPP red blood cells are partially deficient in spectrin and contain a mutant alpha or beta-spectrin that is defective in terms of spectrin self-association. Although the nature of the latter defect has been studied in considerable detail and many mutations of alpha-spectrin and beta spectrin have been identified, the molecular basis of spectrin deficiency is unknown. Here we report two mechanisms underlying spectrin deficiency in HPP. The first mechanism involves a thalassemia-like defect characterized by a reduced synthesis of alpha-spectrin as shown by studies involving synthesis of spectrin in two unrelated HPP probands and their parents: One parent carries the elliptocytogenic spectrin mutation, whereas the other parent is fully asymptomatic. Peripheral blood mononuclear cells as a source of erythroid burst-forming unit (BFUe) were cultured in a two-phase liquid culture system that gives rise to terminally differentiated erythroblasts. Pulse-labeling studies of an equal number of erythroblasts or morphologically identical maturity showed that the synthesis of alpha-spectrin as well as the mRNA levels as measured by the competitive polymerase chain reaction (PCR) method are markedly reduced in the presumed asymptomatic carriers and the HPP probands. In contrast, the synthesis and mRNA levels of beta-spectrin were normal. These results constitute a direct demonstration of an alpha-spectrin synthetic defect in a subset of asymptomatic carriers of HPP and HPP probands. The second mechanism underlying spectrin deficiency involves increased degradation of mutant spectrin before its assembly on the membrane. This is evidenced by pulse labeling studies of erythroblasts from a patient with HPP associated with a homozygous state for spectrin alpha I/46 mutation (leu-pro mutation at AA 207 of alpha-spectrin). These studies showed that although spectrin is synthesized in the cytosol in normal amounts, the rate of turnover of alpha-spectrin is faster resulting in about 40% to 50% reduced assembly of alpha-spectrin and beta-spectrin on the membrane. Thus, spectrin deficiency in this case is at least in part caused by increased susceptibility of the mutant spectrin to degradation before its assembly on the membrane. We conclude that at least two separate mechanisms underlie the molecular basis of spectrin deficiency in HPP.
Topics: Adolescent; Adult; Anemia, Hemolytic, Congenital; Base Sequence; Cells, Cultured; Erythroblasts; Erythrocytes; Erythrocytes, Abnormal; Female; Humans; Membrane Proteins; Molecular Sequence Data; Mutation; RNA, Messenger; Spectrin
PubMed: 8364214
DOI: No ID Found -
Frontiers in Physiology 2021The current study aims at evaluating the toxicity of hydroxychloroquine (HCQ) as a pharmaceutical residue in catfish () and the protective role of (SP). Four groups...
The current study aims at evaluating the toxicity of hydroxychloroquine (HCQ) as a pharmaceutical residue in catfish () and the protective role of (SP). Four groups were used in this study: (1) a control group, (2) a group exposed to 3.16 mg/l of HCQ, (3) a group exposed to 3.16 mg/l of HCQ + 10 mg/l of SP, and (4) a group exposed to 3.16 mg/l of HCQ + 20 mg/l of SP for 15 days of exposure. The HCQ-treated group showed a significant decline in the hematological indices and glucose, total protein, and antioxidant levels in relation to the control group, whereas the HCQ-treated group showed a significant increase in the levels of creatinine, uric acid, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) as well as the percentage of poikilocytosis and nuclear abnormalities of RBCs in relation to the control group. The histopathological evaluation of the liver indicated dilation of the central vein, vacuolization, degeneration of hepatocytes and pyknotic nuclei, as well as reduction of glomeruli, dilation of Bowman's space, and degeneration of renal tubules in the kidney of the HCQ-treated group. (SP) rendered the hematological and biochemical indexes as well as antioxidant levels and the histological architecture to normal status in a dose-dependent manner. Accordingly, the current study recommends the use of SP to remedy the toxic effects of HCQ.
PubMed: 34295262
DOI: 10.3389/fphys.2021.683669 -
Blood Dec 2006Actin oligomers are a significant structural component of the erythrocyte cytoskeleton. Rac1 and Rac2 GTPases regulate actin structures and have multiple overlapping as...
Actin oligomers are a significant structural component of the erythrocyte cytoskeleton. Rac1 and Rac2 GTPases regulate actin structures and have multiple overlapping as well as distinct roles in hematopoietic cells; therefore, we studied their role in red blood cells (RBCs). Conditional gene targeting with a loxP-flanked Rac1 gene allowed Crerecombinase-induced deletion of Rac1 on a Rac2 null genetic background. The Rac1(-/-);Rac2(-/-) mice developed microcytic anemia with a hemoglobin drop of about 20% and significant anisocytosis and poikilocytosis. Reticulocytes increased more than 2-fold. Rac1(-/-);Rac2(-/-) RBCs stained with rhodamine-phalloidin demonstrated F-actin meshwork gaps and aggregates under confocal microscopy. Transmission electron microscopy of the cytoskeleton demonstrated junctional aggregates and pronounced irregularity of the hexagonal spectrin scaffold. Ektacytometry confirmed that these cytoskeletal changes in Rac1(-/-);Rac2(-/-) erythrocytes were associated with significantly decreased cellular deformability. The composition of the cytoskeletal proteins was altered with an increased actin-to-spectrin ratio and increased phosphorylation (Ser724) of adducin, an F-actin capping protein. Actin and phosphorylated adducin of Rac1(-/-);Rac2(-/-) erythrocytes were more easily extractable by Triton X-100, indicating weaker association to the cytoskeleton. Thus, deficiency of Rac1 and Rac2 GTPases in mice alters actin assembly in RBCs and causes microcytic anemia with reticulocytosis, implicating Rac GTPases as dynamic regulators of the erythrocyte cytoskeleton organization.
Topics: Actin Cytoskeleton; Anemia; Animals; Calmodulin-Binding Proteins; Carrier Proteins; Erythrocyte Membrane; Mice; Mice, Knockout; Microfilament Proteins; Neuropeptides; Phosphorylation; Protein Processing, Post-Translational; Reticulocytes; Reticulocytosis; Spectrin; rac GTP-Binding Proteins; rac1 GTP-Binding Protein; RAC2 GTP-Binding Protein
PubMed: 16882712
DOI: 10.1182/blood-2006-03-005942 -
Blood Aug 2000Absence of band 3, associated with the mutation Coimbra (V488M) in the homozygous state, caused severe hereditary spherocytosis in a young child. Although prenatal...
Absence of band 3, associated with the mutation Coimbra (V488M) in the homozygous state, caused severe hereditary spherocytosis in a young child. Although prenatal testing was made available to the parents, it was declined. Because the fetus stopped moving near term, an emergency cesarean section was performed and a severely anemic, hydropic female baby was delivered. She was resuscitated and initially kept alive with respiratory assistance and hypertransfusion therapy. Cord blood smears revealed erythroblastosis, poikilocytosis, and red cells with stalk-like elongations. Band 3 and protein 4.2 were absent; spectrin, ankyrin, and glycophorin A were significantly reduced. Renal tubular acidosis was detected by the age of 3 months. Nephrocalcinosis appeared soon thereafter. After 3 years of follow-up the child is doing reasonably well on a regimen that includes regular blood transfusions and daily bicarbonate supplements. The long-term prognosis remains uncertain given the potential for hematologic and renal complications. (Blood. 2000;96:1602-1604)
Topics: Acidosis, Renal Tubular; Anion Exchange Protein 1, Erythrocyte; Female; Gene Deletion; Humans; Spherocytosis, Hereditary
PubMed: 10942416
DOI: No ID Found -
The Journal of Clinical Investigation Mar 1987To explain the transient anemia and poikilocytosis seen during infancy in hereditary elliptocytosis (HE), we resealed erythrocyte (RBC) ghosts from affected children or...
To explain the transient anemia and poikilocytosis seen during infancy in hereditary elliptocytosis (HE), we resealed erythrocyte (RBC) ghosts from affected children or their elliptocytic parents with 2,3-diphosphoglycerate (DPG) (0-8 mM), a compound that dissociates membrane skeletons, then measured ghost mechanical stability in the ektacytometer. Without added 2,3-DPG, ghost mechanical stability was subnormal in infantile poikilocytosis (IP) and HE but was even more abnormal in hereditary pyropoikilocytosis (HPP). Addition of 2,3-DPG (2.55 mM) to IP or HE ghosts, decreased their stability to that of HPP ghosts (without 2,3-DPG). Nonphysiological 2,3-DPG levels (6-8 mM) were required to elicit a similar effect in normal ghosts. The data suggest that free 2,3-DPG, present in neonatal RBC as a consequence of diminished binding to HbF, may render HE susceptible to in vivo fragmentation. The developmental switch from fetal to adult hemoglobin, by diminishing available free 2,3-DPG, may explain the abatement of poikilocytosis and hemolytic anemia that accompanies maturation.
Topics: 2,3-Diphosphoglycerate; Diphosphoglyceric Acids; Elliptocytosis, Hereditary; Erythrocyte Deformability; Erythrocyte Membrane; Erythrocytes, Abnormal; Female; Hot Temperature; Humans; Infant, Newborn; Macromolecular Substances; Male; Osmolar Concentration; Spectrin
PubMed: 3818955
DOI: 10.1172/JCI112905 -
Haematologica Mar 2008beta-thalassemia is one of the most common genetic diseases in the world and requires extensive therapy. Lentiviral-mediated gene therapy has been successfully exploited...
BACKGROUND
beta-thalassemia is one of the most common genetic diseases in the world and requires extensive therapy. Lentiviral-mediated gene therapy has been successfully exploited in the treatment of beta-thalassemia and showed promise in clinical application. Using a human beta-globin transgenic mouse line in a beta-thalassemia diseased model generated with a lentiviral-mediated approach, we investigate the stable therapeutic effect on a common thalassemia syndrome.
DESIGN AND METHODS
Human beta-globin gene lentiviral vector was constr ucted, followed by subzonal microinjection into single-cell embryos of beta(IVS-2-654)-thalassemia mice to generate a transgenic line. Human beta-globin gene expression was examined with RT-PCR, Western-blotting and ELISA. The hematologic parameters and tissue pathology were investigated over time in founder mice and their off-spring.
RESULTS
Transgenic mice with stable expression of the lentivirus carrying human beta-globin gene were obtained. A marked improvement in red blood cell indices and a dramatic reduction in red blood cell anisocytosis, poikilocytosis and target cells were observed. Nucleated cell proportion was greatly decreased in bone marrow, and splenomegaly with extramedullary hematopoiesis was ameliorated. Iron deposition in liver was also reduced. There was a two-fold increase in the survival rate of the beta(IVS-2-654) mice carrying human beta-globin transgene. Significantly, the germline integration of the lentiviral construct was obtained and stable hematologic phenotype correction was observed over the next two generations of the transgenic mice.
CONCLUSIONS
The generation of human beta-globin transgenic mice in a beta(IVS-2-654)-thalassemia mouse mediated with lentiviral vectors provides a useful model and offers an attractive means to investigate the transgenic stable therapeutic effect in beta-thalassemia.
Topics: Animals; Bone Marrow; Disease Models, Animal; Female; Genetic Therapy; Genetic Vectors; Germ-Line Mutation; Globins; Humans; Lentivirus; Liver; Male; Mice; Mice, Mutant Strains; Mice, Transgenic; Microinjections; Mutagenesis, Insertional; Recombinant Fusion Proteins; Spleen; Virus Integration; beta-Thalassemia
PubMed: 18268280
DOI: 10.3324/haematol.12010 -
Frontiers in Neurology 2019Migraine is a debilitating primary headache disorder with a poorly understood aetiology. An extensive body of literature supports the theory of migraine as a systemic...
Migraine is a debilitating primary headache disorder with a poorly understood aetiology. An extensive body of literature supports the theory of migraine as a systemic vascular inflammatory disorder characterised by endothelial dysfunction. It is also well-known that chronic inflammation results in an excessive burden of oxidative stress and therefore cellular dysfunction. In this study the effects of excessive oxidative stress through the phases of female migraine-with-aura (FMA) were evaluated by examining the health of the systems of haemostasis. Blood was obtained from 11 FMA patients at baseline and during the headache phase of migraine, as well as from 8 healthy age-matched female controls. Samples were analysed using thromboelastography (TEG) to evaluate viscoelastic profiles, light microscopy for erythrocyte morphology, Scanning Electron Microscopy (SEM) for erythrocyte and fibrin clot structure, confocal microscopy for β-amyloid detection in fibrin clots. Viscoelastic profiles from platelet poor plasma showed decreased clot reaction times in FMA at baseline (95% CI [5.56, 8.41]) vs. control (95% CI [7.22, 11.68]); as well as decreased time to maximum thrombus generation for the same comparison (95% CI [6.78, 10.20] vs. [8.90, 12.96]). Morphological analysis of erythrocytes indicated widespread macrocytosis, poikilocytosis and eryptosis in the migraineurs. Analysis of fibrin networks indicated that this hypercoagulability may be a result of aberrant fibrin polymerisation kinetics caused by the adoption of a β-amyloid conformation of fibrin(ogen). The results reaffirm the hypercoagulable state in migraine, and would suggest that this state is most likely a result of a systemic inflammatory state which induces oxidative damage to both erythrocytes and fibrin(ogen) in female episodic migraine-with-aura. Furthermore, if the amylodogenic changes to fibrin(ogen) were observed in a larger cohort, this would support theories of micro-embolisation in migraine-with-aura.
PubMed: 31849822
DOI: 10.3389/fneur.2019.01262 -
The Journal of Clinical Investigation Sep 1981Hereditary pyropoikilocytosis (HPP) is a hemolytic anemia characterized by microspherocytosis, poikilocytosis, and an unusual thermal sensitivity of erythrocytes. We...
Hereditary pyropoikilocytosis (HPP) is a hemolytic anemia characterized by microspherocytosis, poikilocytosis, and an unusual thermal sensitivity of erythrocytes. We have investigated the contribution of abnormal membrane skeletal assembly to these abnormal HPP erythrocyte properties. Skeletons prepared from fresh HPP ghosts with Triton X-100 were considerably more fragile than skeletons from control erythrocytes. Spectrin, the major skeleton component, extracted at 0 degrees C from normal erythrocytes, was present primarily as tetramers and high molecular weight complexes. In contrast, spectrin extracted from HPP erythrocytes under identical conditions contained a significant amount of dimers with a concomitant decrease of tetramers. Furthermore, spectrin dimers from HPP erythrocytes differed from normal spectrin dimers in their failure to reassociate into tetramers both in solution and in the membrane. Presumptive HPP carriers (asymptomatic mothers of the two patients) exhibited a mild but reproducible increase of spectrin dimers in 0 degrees C extracts and a defective reassociation of spectrin dimers of tetramers both in solution and in the membrane. We conclude that in HPP, self-association of spectrin dimers into tetramers is defective, which accounts for the instability of membrane skeletons.
Topics: Cytoplasm; Erythrocyte Membrane; Erythrocytes, Abnormal; Humans; Kinetics; Macromolecular Substances; Membrane Proteins; Protein Binding; Spectrin; Spherocytosis, Hereditary
PubMed: 7276161
DOI: 10.1172/jci110293 -
American Journal of Hematology Jan 2003Myelofibrosis is characterized by reticulin fibrosis of the bone marrow with resulting features of myelophthisis. Besides hematopoietic malignancies and other neoplasms...
Myelofibrosis is characterized by reticulin fibrosis of the bone marrow with resulting features of myelophthisis. Besides hematopoietic malignancies and other neoplasms involving the bone marrow, myelofibrosis has been described in association with autoimmune disorders, especially systemic lupus erythematosus. We describe the clinicopathologic features of a primary form of autoimmune myelofibrosis (AIMF) in patients who do not have systemic lupus erythematosus or another well-defined autoimmune syndrome. Absence of marked splenomegaly, peripheral blood cytopenias with mild teardrop poikilocytosis and leukoerythroblastosis, bone marrow lymphoid aggregates, and presence of autoantibodies are some of the salient features of primary AIMF. AIMF should especially be differentiated from chronic idiopathic myelofibrosis, a neoplastic myeloproliferative disease. Primary AIMF appears to have an excellent prognosis, with all patients reported in this series responding to a short course of corticosteroid therapy.
Topics: Adrenal Cortex Hormones; Adult; Aged; Autoantibodies; Autoimmune Diseases; Bone Marrow; Comorbidity; Diagnosis, Differential; Female; Fever; Fibrosis; Humans; Immunosuppressive Agents; Male; Megakaryocytes; Middle Aged; Primary Myelofibrosis; Spleen; Sweating
PubMed: 12508261
DOI: 10.1002/ajh.10258