Codanin-1 mutations in congenital dyserythropoietic anemia type 1 affect HP1{alpha} localization in erythroblasts

Congenital dyserythropoietic anemia type 1 (CDA-1), a rare inborn anemia characterized by abnormal chromatin ultrastructure in erythroblasts, is caused by abnormalities in codanin-1, a highly conserved protein of unknown function. We have produced 3 monoclonal antibodies to codanin-1 that demonstrate its distribution in both nucleus and cytoplasm by immunofluorescence and allow quantitative measurements of patient and normal material by Western blot. A detailed analysis of chromatin structure in CDA-1 erythroblasts shows no abnormalities in overall histone composition, and the genome-wide epigenetic landscape of several histone modifications is maintained. However, immunofluorescence analysis of intermediate erythroblasts from patients with CDA-1 reveals abnormal accumulation of HP1α in the Golgi apparatus. A link between mutant codanin-1 and the aberrant localization of HP1α is supported by the finding that codanin-1 can be coimmunoprecipitated by anti-HP1α antibodies. Furthermore, we show colocalization of codanin-1 with Sec23B, the protein defective in CDA-2 suggesting that the CDAs might be linked at the molecular level. Mice containing a gene-trapped Cdan1 locus demonstrate its widespread expression during development. Cdan1(gt/gt) homozygotes die in utero before the onset of primitive erythropoiesis, suggesting that Cdan1 has other critical roles during embryogenesis.     

Tuberculin reactivity among health care workers in nonhospital settings

BACKGROUND: We used workers' compensation data to identify health care workers at risk of tuberculosis exposure in the hospital and nonhospital environment. METHODS: We identified State Fund workers' compensation claims having a documented tuberculin skin test (TST) conversion (size >or=10 mm) with a previous negative skin test between 1996 and 2000 in the State of Washington. RESULTS: Health care workers experienced an overall accepted workers' compensation claim rate of 2.3 claims/10,000 full-time equivalent employees (FTEs) per year for tuberculin reactivity. Receptionists accounted for the largest number, with 18.4% tuberculin reactivity claims. The number of tuberculin reactivity claims was the highest for offices and clinics of doctors of medicine (3.7 per 10,000 FTEs), followed by medical laboratories (2.6 per 10,000 FTEs). CONCLUSION: This study allowed characterization of employees in various nonhospital health services locations with higher number of tuberculin reactivity.     

Smokeless tobacco-induced lamellar body abnormalities

OBJECTIVES: To compare the morphological changes and quantitative distribution of lamellar bodies (Lb) (membrane coating granules) in the hamster cheek pouch epithelium with smokeless tobacco (ST). MATERIALS AND METHODS: Archives of experimental material from previously published studies [S. Ashrafi, A. Das, R. Worawongvasu, B. Mehdinejad and J. Waterhouse (1992) Scanning Microscopy6: 183] were utilized. Animals in experimental group received most ST (snuff) in their right pouch, 5 days weekly, for 24 months, while no snuff was given to control group. After 24 months, the epithelial tissues were processed for electron microscopic study. Volume densities of Lb were assessed by morphometry. MAIN OUTCOME MEASURES: Densities of Lb in the two groups, experimental vs control. RESULTS: In the control, Lb extruded their contents into the intercellular spaces of upper granular layers and in between the last granular cell layers and keratin layers to form a permeability barrier. Conversely, in the smokeless tobacco-treated epithelium, the majority of the Lb that were formed remained inside and accumulated within the granular cells, without extruding their contents into the intercellular spaces to form a lipid compound permeability barrier. CONCLUSIONS: Commercial alkaline ST may have contributed to the abnormal accumulation of Lb in the granular cell layer and affected the extrusion process of Lb to form an incomplete permeability barrier in the oral epithelium.     

Association between aldosterone production and variation in the 11beta-hydroxylase (CYP11B1) gene

CONTEXT: Variation in the region of chromosome 8 including the genes steroid 11beta-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) influences mineralocorticoid and glucocorticoid metabolism. However, the relative importance of polymorphisms in CYP11B1 and CYP11B2 in determining these phenotypes is unknown. OBJECTIVE: Our objective was to investigate genetic influences of the CYP11B1 and CYP11B2 genes on mineralocorticoid metabolism. DESIGN: We measured 24-h urinary excretion of the key metabolites of the principal mineralocorticoids, glucocorticoids and androgens secreted by the adrenal cortex. We genotyped polymorphisms spanning the CYP11B1 and CYP11B2 genes, which together capture all common variations at the locus. PARTICIPANTS: Participants included 573 members of 105 British Caucasian families ascertained on a hypertensive proband. MAIN OUTCOME MEASURES: We assessed heritability of urinary tetrahydroaldosterone (THAldo) excretion and association of THAldo excretion with genotype. RESULTS: The heritability of THAldo excretion was 52% (P < 10(-6)). There was significant association between THAldo and genotype at several of the CYP11B1/B2 polymorphisms. The strongest association was observed at the rs6387 (2803A/G) polymorphism in intron 3 of CYP11B1 (P = 0.0004). Association followed a codominant model with a 21% higher THAldo excretion per G allele. Genotype at rs6387 accounted for 2.1% of the total population variability of THAldo. We found significant association between THAldo excretion and urinary total androgen excretion, urinary tetrahydrodeoxycortisol level, and urinary cortisol metabolites (all P < 0.001). CONCLUSIONS: Aldosterone synthesis is highly heritable and is affected by genotype at CYP11B1. Our findings support the hypothesis that genetically determined differences in 11-hydroxylation efficiency can have downstream effects on mineralocorticoid synthesis. Such effects may be of relevance to the development of low-renin essential hypertension.     

Percutaneous implantation of the Edwards SAPIEN™ pulmonic valve: initial results in the first 22 patients

Background

Percutaneous pulmonary valve implantation (PPVI) was introduced in 2000 as an interventional procedure for the treatment of right ventricular outflow tract (RVOT) dysfunction. The new Edwards SAPIEN^? pulmonic valve has reached CE certification at the end of 2010 thus offering an attractive alternative with extended sizes (23 and 26 mm) to the conventional Melody^® valve (sizes 18, 20 and 22 mm).

Patients

Over a 1-year period, PPVI using the Edwards SAPIEN^? pulmonic valve was performed in 22 patients using a standardized procedure. Primary diagnosis was tetralogy of Fallot (n = 11), pulmonary atresia (n = 2), Truncus arteriosus (n = 3), TGA/PS-Rastelli (n = 1), Ross surgery (n = 2), double outlet right ventricle (n = 2) and absent pulmonary valve syndrome (n = 1). The character of the RVOT for PPVI was transannular patch (n = 4), bioprosthesis (n = 2), homograft (n = 5) and Contegra^® conduit (n = 11). The leading hemodynamic problem consisted of a pulmonary stenosis (PS) (n = 2), pulmonary regurgitation (PR) (n = 11) and a combined PS/PR lesion (n = 9).

Results

In 21/22 patients, PPVI was performed successfully (10 × 23 and 11 × 26 mm). There were 9 female and 13 male patients; the mean age was 21.7 years (range 6–83 years), the mean length was 162 cm (range 111–181 cm) and the weight 56.5 kg (range 20–91 kg). Invasive data showed a decrease of RV-systolic pressure from 61.2 mmHg (±23.1) to 41.2 mmHg (±8.6) and reduction of RV–PA gradient from 37.3 mmHg (±23.2) to 6.9 mmHg (±5.3). The PA-systolic pressure increased from 25.8 mmHg (±8.6) to 33.9 mmHg (±9.3) as did the PA diastolic pressure (from 6.0 mmHg (±5.6) to 14.6 mmHg (±4.3). There was a substantial reduction of pulmonary regurgitation from before (none/trivial n = 0, mild n = 2, mode rate n = 9, severe n = 11) to after PPVI (none/trivial n = 20, mild n = 1). During the short-term follow-up of 5.7 months there was no change in the immediate results.

Conclusion

PPVI using the Edwards SAPIEN^? pulmonic valve can be performed safely in a wide range of patients with various diagnoses and underlying pathology of the RVOT and enables the restoration of an adult-size RVOT diameter. Although the immediate and short-term results seem promising, the long-term effects and safety have to be assessed in further clinical follow-up studies.     

ICAM-3 expression on endothelium in lymphoid malignancy.

Intercellular adhesion molecule-3 (ICAM-3), the third receptor for lymphocyte function-associated antigen molecule-1 and a new member of the immunoglobulin superfamily has been recently characterized using specific monoclonal antibodies. In the present study, we show immunocytochemically that ICAM-3 is present on T and B cells in the mantle zones and on a subpopulation of follicular center cells in reactive lymph nodes and only occasionally in endothelium. In 52 cases of Hodgkin's disease, ICAM-3, although present on the majority of the reactive lymphoid cells, was absent from the Reed-Sternberg cells and their variants. However, in 28 cases (54%), there was prominent endothelial staining in small vessels. Similar findings were noted in 16 out of 49 cases (33%) of non-Hodgkin's lymphomas. This finding suggests that analogous to ICAM-1 and ICAM-2, ICAM-3 expression can be induced on endothelial cells in lymphoid neoplasms, probably by an as yet unidentified cytokine-mediated mechanism.