(1/24) beta-Spectrin Sao PauloII, a novel frameshift mutation of the beta-spectrin gene associated with hereditary spherocytosis and instability of the mutant mRNA.

Hereditary spherocytosis (HS) is a common inherited anemia characterized by the presence of spherocytic red cells. Defects in several membrane protein genes have been involved in the pathogenesis of HS. beta-Spectrin-related HS seems to be common. We report here a new mutation in the beta-spectrin gene coding region in a patient with hereditary spherocytosis. The patient presented acanthocytosis and spectrin deficiency and, at the DNA level, a novel frameshift mutation leading to HS, i.e., a C deletion at codon 1392 (beta-spectrin Sao PauloII), exon 20. The mRNA encoding beta-spectrin Sao PauloII was very unstable and the mutant protein was not detected in the membrane or in other cellular compartments. It is interesting to note that frameshift mutations of the beta-spectrin gene at the 3' end allow the insertion of the mutant protein in the red cell membrane, leading to a defect in the auto-association of the spectrin dimers and consequent elliptocytosis. On the other hand, beta-spectrin Sao PauloII protein was absent in the red cell membrane, leading to spectrin deficiency, HS and the presence of acanthocytes.  (+info)

(2/24) Acanthocytes of Stropharia rugosoannulata function as a nematode-attacking device.

Efficient killing of nematodes by Stropharia rugosoannulata Farlow ex Murrill cultures was observed. This fungus showed the ability to immobilize the free-living nematode Panagrellus redivivus Goodey within minutes and to immobilize the pine wilt nematode Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle within hours on agar plates. Moreover, P. redivivus worms were completely degraded by the fungus within 24 to 48 h. The cultures of S. rugosoannulata studied shared the characteristic of abundantly producing cells with finger-like projections called acanthocytes. We showed that the nematode-attacking activity of this fungus is carried out by these spiny acanthocytes and that mechanical force is an important factor in the process. Furthermore, the growth and nematode-attacking activity of the fungus in soil were also determined, and our results suggest that acanthocytes are functional in soil.  (+info)

(3/24) Autopsy case of Dubin-Johnson syndrome with pneumonia and abetalipoproteinemia-like lipid profile.

We report the autopsy of a 79-year-old Japanese woman with Dubin-Johnson syndrome accompanied by pneumonia, an abetalipoproteinemia-like lipid profile and acanthocytosis. On admission, physical examination of the patient revealed malnutrition. Blood tests revealed marked inflammatory changes and mild liver dysfunction. Chest X-ray indicated bilateral pneumonia. Total cholesterol, low-density lipoprotein (LDL) cholesterol and triglyceride levels were 89 mg/dL, 5 mg/dL and 6 mg/dL, respectively. Peripheral blood smears revealed numerous acanthocytes. Despite the administration of antibiotics and nutritional support, the patient died. Autopsy revealed a black liver, atrophy of fat tissue on the mesentery, and pneumonia with bilateral pleural effusion. We believe that the abetalipoproteinemia-like lipid profiles in this case were caused by malnutrition and the inflammatory changes rather than the direct effects of Dubin-Johnson syndrome. We base this conclusion on the following three findings: 1) the patient's lipid profile before hospitalization was in the normal range, 2) her serum LDL cholesterol and triglyceride levels gradually increased after nutritional support began, and 3) blood tests revealed marked inflammatory changes (C-reactive protein 9.0 mg/dL; interleukin-6 16.4 pg/mL). This case provides important information that enhances our understanding of lipid metabolism under conditions of malnutrition and inflammation.  (+info)

(4/24) Insights into extensive deletions around the XK locus associated with McLeod phenotype and characterization of two novel cases.

The McLeod phenotype is derived from various forms of XK gene defects that result in the absence of XK protein, and is defined hematologically by the absence of Kx antigen, weakening of Kell system antigens, and red cell acanthocytosis. Individuals with the McLeod phenotype usually develop late-onset neuromuscular abnormalities known as the McLeod syndrome (MLS). MLS is an X-linked multi-system disorder caused by absence of XK alone, or when the disorder is caused by large deletions, it may be accompanied with Duchenne muscular dystrophy (DMD), chronic granulomatous disease (CYBB), retinitis pigmentosa (RPGR), and ornithine transcarbamylase deficiency (OTC). XK defects derived from a large deletion at the XK locus (Xp21.1) have not been characterized at the molecular level. In this study, the deletion breakpoints of two novel cases of McLeod phenotype with extensive deletions are reported. Case 1 has greater than 1.12 million base-pairs (mb) deletion around the XK locus with 7 genes affected. Case 2 has greater than 5.65 mb deletion from TCTE1L to DMD encompassing 20 genes. Phylogenetic analyses demonstrated that DMD, XK and CYBB have close paralogs, some of which may partially substitute for the functions of their counterparts. The loci around XK are highly conserved from fish to human; however, the disorders are probably specific to mammals, and may coincide with the translocation of the loci to the X chromosome after the speciation in birds. The non-synonymous to synonymous nucleotide substitution rate ratio (omega=dN/dS) in these genes was examined. CYBB and RPGR show evidence of positive selection, whereas DMD, XK and OTC are subject to selective constraint.  (+info)

(5/24) Beta-spectrinBari: a truncated beta-chain responsible for dominant hereditary spherocytosis.

 (+info)

(6/24) The acanthocyte-echinocyte differential: The example of chorea-acanthocytosis.

 (+info)

(7/24) Drug-induced hemolytic anemia and thrombocytopenia associated with alterations of cell membrane lipids and acanthocyte formation.

 (+info)

(8/24) Erythrocyte membrane changes of chorea-acanthocytosis are the result of altered Lyn kinase activity.

 (+info)

• 1
• 2
• 3