PARVOVIRUS B19-INDUCED PERSISTENT PURE RED CELL APLASIA IN A CHILD WITH T-CELL IMMUNODEFICIENCY

Persistent pure red cell aplasia can be a manifestation of parvovirus B19 infection in immunocompromised hosts. Failure of the humoral immune response to clear parvovirus B19 in such patients results in persistent pure red cell aplasia. The authors describe a child who had T-cell immunodeficiency and persistent pure red cell aplasia due to parvovirus B19 infection. Interestingly, they detected human parvovirus B19 genome by polymerase chain reaction (PCR) not in the peripheral blood, but in the bone marrow specimen of the patient. In their patient, T-cell immunodeficiency may have caused impaired B-cell activation and failure of effective humoral immune response to neutralize the virus. Additionally, before the diagnosis of pure red cell aplasia, IVIG treatment given at a dosage of 400 mg/kg/day with 3-week intervals may result in sufficient neutralization of peripheral blood parvovirus B19, whereas it may not be sufficient for the neutralization of parvovirus B19 genome in bone marrow. Thus, peripheral blood parvovirus B19 serology (IgM and IgG) and PCR were negative, whereas bone marrow aspiration sample was positive for parvovirus B19 PCR in this patient. Reticulocytopenia and severe anemia may warn the physicians of parvovirus B19 infection, especially in immunocompromised children. Diagnosis may require demonstration of absence of late erythroid precursors in the bone marrow as well as serologic testing and detection of parvovirus B19 genome by PCR in the serum and/or bone marrow samples of the patient.     

苯乙哌啶合成的改进

目的：改进苯乙哌啶的合成方法,使之更适合工业化生产。方法,以N,N－双（β-氯乙基）对甲苯磺酰胺为原料,利用液－液相转移催化方法制得1－对甲苯磺酰基－4－氰基哌啶,再经水解,酯化,缩合,成盐等步骤,合成了苯乙哌啶。结果：总收率可达51．8％,结论：此合成方法适合工业化生产。     

Hematoxylin and Safranin O Staining of Frozen Sections

Currently the hematoxylin and eosin staining procedure is the most popular among Mohs surgeons for histology. However, safranin O, a cheaper and relatively safer stain which is predominantly used for plant histology, should be considered as it offers similar or improved accuracy in the diagnosis of frozen sections of basal and squamous cell carcinomas.     

Muscle involvement in two Behçet cases: magnetic resonance imaging and histology findings

Behçet’s disease (BD) is a systemic vasculitis with a classic trio of symptoms of oral aphthous ulcers, genital ulcers, and ocular lesions that present in a relapsing fashion. Despite these most frequently encountered symptoms of the disease, other systems such as vascular, gastrointestinal, and neurological involvements can also occur. Muscular involvement is rare, and there are only a few cases in the literature, which were reported mainly in a pediatric population. In this two-adult case report, muscular involvement of BD with an emphasis on magnetic resonance imaging and histology findings will be presented.     

Rapid Rh D genotyping by polymerase chain reaction-based amplification of DNA

Rh (rhesus) D is the dominant antigen of the Rh blood group system. Recent advances in characterization of the nucleotide sequence of the cDNA(s) encoding the Rh D polypeptide allow the determination of the Rh D genotype at the DNA level. This can be of help in cases in which red blood cells are not available for phenotyping, eg, when in concerns a fetus. We have tested three independent DNA typing methods based on the polymerase chain reaction (PCR) for their suitability to determine the Rh D genotype. DNA derived from peripheral blood mononuclear cells from 234 Rh-phenotyped healthy donors (178 Rh D positive and 56 Rh D negative) was used in the PCR. The Rh D genotypes, as determined with a method based on the allele-specific amplification of the 3' noncoding region of the Rh D gene described by Bennett et al (N Engl J Med 329:607, 1993), were not concordant with the serologically established phenotypes in all cases. We have encountered 5 discrepant results, ie, 3 false-positive and 2 false-negative (a father and child). Rh D genotyping with the second method was performed by PCR amplification of exon 7 of the D gene with allele-specific primers. In all donors phenotyped as D positive tested so far (n = 178), the results of molecular genotyping with this method were concordant with the serologic results, whereas a false-positive result was obtained in one of the D-negative donors (also false-positive in the first method). Complete agreement was found between genotypes determined in the third method, based on a 600-bp deletion in intron 4 of the Rh D gene described by Arce et al (Blood 82:651, 1993), and serologically determined phenotypes. The Rh blood group system is complex, and unknown polymorphisms at the DNA level are expected to exist. Therefore, although genotypes determined by the method of Arce et al were in agreement with serotypes, it cannot yet be regarded as the golden standard. More experience with this or other methods is still needed.     

Sulfhydryl reducing agents and shape regulation in human erythrocytes

Metabolic crenation of red cells is reversible; on addition of nutrients, echinocytes recover the normal discoid shape. When the shape recovery takes place in the presence of reducing agents such as dithiothreitol (DTT), morphological change continues until the cells are stomatocytic. The degree of stomatocytosis varies, depending on the cell morphology when the nutrients and reducing agent are added. DTT has minimal effect on the shape of normal discocytes, but in its presence, mildly echinocytic cells become slightly cupped and advanced- stage echinocytes become severely stomatocytic. DTT must be present continuously for development and retention of stomatocytosis; echinocytes preincubated with or metabolically depleted in DTT do not become stomatocytic when supplemented in the absence of DTT, and DTT- induced stomatocytes revert to discocytes when the reducing agent is removed. DTT has no effect on adenosine triphosphate synthesis or equilibrium cell glutathione levels, and the induced stomatocytosis is not inhibited by excluding oxygen from cells during depletion. Spectrin phosphorylation and phosphate turnover are not affected by DTT. The echinocyte-to-discocyte transformation coincides with phosphorylation of membrane inner monolayer lipids (diacylglycerol to phosphatidic acid and phosphatidylinositol to phosphatidylinositol-4,5-bisphosphate). Overphosphorylation of these phospholipids is not responsible for the exaggerated shape recovery seen with reducing agents; phosphorylation of inner monolayer lipids proceeds identically in the presence and absence of DTT.     

Association of cell cycle expression of Ia-like antigenic determinations on normal human multipotential (CFU-GEMM) and erythroid (BFU-E) progenitor cells with regulation in vitro by acidic isoferritins

An association has been established between human Ia-like antigenic determinants, expression during DNA synthesis on multipotential (CFU- GEMM) and erythroid (BFU-E) progenitor cells, and the regulatory action of acidic isoferritins in vitro. Treatment of human bone marrow cells with monoclonal anti-Ia (NE1-011) plus complement inhibited colony formation of CFU-GEMM) and BFU-E by 50%-70%. Reduction of colonies was similar whether bone marrow cells were exposed to anti-Ia plus complement, high specific tritiated thymidine (3HTdr), or acidic isoferritins. No further decrease was apparent with 3HTdr or acidic isoferritins after Ia-antigen+ CFU-GEMM or BFU-E were removed, or with anti-Ia plus complement or acidic isoferritins after S-phase CFU-GEMM or BFU-E were removed. Anti-Ia, in the absence of complement, had no effect on colony formation but blocked the inhibition of CFU-GEMM and BFU-E by acidic isoferritins. Demonstration of Ia-antigens on BFU-E and inhibition of BFU-E by acidic isoferritins appeared to require the presence of phytohemmagglutinin leukocyte conditioned medium (PHA-LCM) in the culture medium during the 14-day incubation period. these results implicate Ia-antigen+ cells, acidic isoferritins, and PHA-LCM in the regulation of multipotential and erythroid progenitor cells in vitro.     

Impaired regeneration in LGMD2A supported by increased PAX7‐positive satellite cell content and muscle‐specific microrna dysregulation

Introduction: Recent in vitro studies suggest that CAPN3 deficiency leads initially to accelerated myofiber formation followed by depletion of satellite cells (SC). In normal muscle, up‐regulation of miR‐1 and miR‐206 facilitates transition from proliferating SCs to differentiating myogenic progenitors. Methods: We examined the histopathological stages, Pax7 SC content, and muscle‐specific microRNA expression in biopsy specimens from well‐characterized LGMD 2A patients to gain insight into disease pathogenesis. Results: Three distinct stages of pathological changes were identified that represented the continuum of the dystrophic process from prominent inflammation with necrosis and regeneration to prominent fibrosis, which correlated with age and disease duration. Pax7‐positive SCs were highest in the fibrotic group and correlated with down‐regulation of miR‐1, miR‐133a, and miR‐206. Conclusions: These observations, and other published reports, are consistent with microRNA dysregulation leading to inability of Pax7‐positive SCs to transit from proliferation to differentiation. This results in impaired regeneration and fibrosis. Muscle Nerve 47: 731–739, 2013