An analysis of fetal hemoglobin variation in sickle cell disease: the relative contributions of the X-linked factor, beta-globin haplotypes, alpha-globin gene number, gender, and age

Five factors have been shown to influence the 20-fold variation of fetal hemoglobin (Hb F) levels in sickle cell anemia (SS): age, sex, the alpha-globin gene number, beta-globin haplotypes, and an X-linked locus that regulates the production of Hb F-containing erythrocytes (F cells), ie, the F-cell production (FCP) locus. To determine the relative importance of these factors, we studied 257 Jamaican SS subjects from a Cohort group identified by newborn screening and from a Sib Pair study. Linear regression analyses showed that each variable, when analyzed alone, had a significant association with Hb F levels (P < .05). Multiple regression analysis, including all variables, showed that the FCP locus is the strongest predictor, accounting for 40% of Hb F variation. beta-Globin haplotypes, alpha-globin genes, and age accounted for less than 10% of the variation. The association between the beta-globin haplotypes and Hb F levels becomes apparent if the influence of the FCP locus is removed by analyzing only individuals with the same FCP phenotype. Thus, the FCP locus is the most important factor identified to date in determining Hb F levels. The variation within each FCP phenotype is modulated by factors associated with the three common beta-globin haplotypes and other as yet unidentified factor(s).     

Imiquimod 5% cream is an acceptable treatment option for external anogenital warts in uncircumcised males

OBJECTIVES: To determine the safety and efficacy of imiquimod (Aldara) 5% cream in the treatment of prepuce-associated warts in uncircumcised males. METHODS: An open-label study in six UK medical centres with 35 uncircumcised males with prepuce-associated warts treated with imiquimod 5% cream three times per week for up to 16 weeks. Other anogenital warts were also treated. RESULTS: Three times weekly application of imiquimod was found to be safe, with erythema as the most commonly reported local skin reaction. Forty per cent of patients had complete clearance of anogenital warts within 16 weeks. CONCLUSIONS: Imiquimod cream at a dosing regimen of three times per week, is effective and has an acceptable safety profile in the treatment of prepuce associated warts and other external anogenital warts in uncircumcised males.     

H2M3wt-restricted, Listeria monocytogenes-immune CD8 T cells respond to multiple formylated peptides and to a variety of gram-positive and gram- negative bacteria

A subset of H2M3wt-restricted, Listeria monocytogenes (LM)-immune CD8 effectors recognize antigen-presenting cells (APC) preincubated with heat-killed LM. The responsible product, which we have previously designated heat-killed Listeria-associated antigen (HAA), is extremely hydrophobic and resistant to proteolytic degradation. Despite the protease resistance of HAA, we now report that HAA-immune clones are uniformly responsive to fMIGWII, a formylated oligopeptide derived from the recently described LM product, lemA. While fMIGWII was by far the most potent peptide tested, over half our clones also responded to the LM-derived peptide fMIVII and cross-reactive responses to two other unrelated formylated peptides at concentrations of <1 microM were frequently observed. One of these peptides (fBlaZ) did not share any amino acid in common with fMIGWII except N-formyl methionine at position 1. Unformylated variants of the same peptides were inactive. HAA-immune CD8 cells also responded in an H2M3wt-restricted manner to APC pretreated with heat-killed or live preparations of other gram- positive and gram-negative bacteria such as Streptococcus pyogenes (SP) and Proteus vulgaris (PV). Unlike fMIGWII which is water soluble and protease sensitive, the native antigens extracted from SP and PV, like HAA, were very hydrophobic and proteinase K resistant, presumably reflecting in each case the association of cross-reactive polypeptides with bacterial lipid or phospholipid. Thus, HAA/lemA-immune, H2M3wt- restricted effectors can respond to a variety of formylated peptides and bacterial antigens in vitro. Similar cross-reactions in vivo might have physiologically significant implications.      

高低通量血液透析膜清除溶质能力的比较

目的：比较高通量和低通量聚砜膜血液透析器对慢性肾功能衰竭维持性血液透析患者尿素氮、肌酐、血磷及β2-微球蛋白的清除能力. 方法：于2004-09/2005-01选择上海交通大学医学院附属新华医院血液透析中心维持性血液透析患者43例,血透时间1.5～5.0年.实验经医院伦理委员会审批,患者均知情同意.①实验分组：按随机数字表法分为高通量透析组23例和低通量透析组20例.②实验方法：高通量透析组采用F60聚砜膜血液透析器,超滤系数Kuf为40 mL/（h·mm Hg）.低通量透析组采用F6聚砜膜血液透析器,超滤系数Kuf为5.5 mL/（h·mm Hg）.所有患者透析3次/周,4 h/次,均采用Fresenius 4008S容量控制型透析机和超纯净水碳酸氢盐透析液,透析液流量500 mL/min,血流量190～250 mL/min,采用肝素抗凝,共5个月.③实验评估：两组患者透析前后常规检测血尿素氮、肌酐、血磷浓度;采用放射免疫方法测定血β2-微球蛋白含量,观察透析前后各种溶质含量变化,计算其溶质清除率. 结果：①血尿素氮、肌酐和血磷浓度变化：两组患者透析前后血尿素氮、肌酐和血磷浓度均显著下降.两组血尿素氮、肌酐和血磷的清除率差异无显著性意义（P＞0.05）,表明高通量和低通量血液透析均能有效清除维持性血液透析患者血液中的小分子溶质.②β2-微球蛋白含量变化：高通量透析组透析后β2-微球蛋白含量显著下降,低通量透析组透析前后β2-微球蛋白含量无显著变化.清除率组间差异有显著性意义（t=3.62,P＜0.05）. 结论：应用高通量F60聚砜膜血液透析器和低通量F6聚砜膜血液透析器均能有效清除维持性血液透析患者血液中的小分子溶质,但高通量F60聚砜膜血液透析器对β2-微球蛋白的清除能力显著优于低通量F6聚砜膜血液透析器.     

Immunoregulation of B lymphocyte colony formation by T cell subsets in patients with chronic lymphocytic leukemia

Normal B lymphocytes are activated, proliferate, and then differentiate into plasma cells and secrete immunoglobulin (Ig). We have reported that chronic lymphocytic leukemia (CLL) T4 cells help and CLL T8 cells lack suppressor effects on Ig synthesis by normal B cells (Blood 62:767, 1983). We have now explored the earlier phase, proliferation, using B cell colony formation; in semisolid media. B lymphocyte colonies from normal individuals and from patients with CLL were grown in 0.3% agarose overlayed with T cells or T cell subsets and the B cell mitogen staphylococcal protein A. Enriched T cells, OKT4 or OKT8, were obtained either by sheep erythrocyte rosettes or depletion of OKT8 or OKT4 cells by monoclonal antibody or complement, respectively. Twenty thousand B cells from normal subjects yielded 65 +/- 9, 64 +/- 7, and 19 +/- 6 colonies with autologous unfractionated T-, OKT4-, or OKT8- positive cells, respectively. This compared to 29 +/- 11, 81 +/- 11, and 15 +/- 4 colonies from patients with CLL with added autologous unfractionated T-, OKT4-, or OKT8-positive cells. To determine whether the fewer number of colonies in both normal subjects and patients with CLL with OKT8-positive cells was due to suppression or lack of help, the number of OKT4-positive cells was held constant, and OKT8-positive cells were added in increasing numbers. No suppression of colony formation could be demonstrated. Furthermore, the addition of increasing numbers of concanavalin A (Con A)-activated OKT8-positive cells did not suppress colony formation. These results suggest that the CLL T cell subsets behave in a functionally similar manner to normal T cell subsets, namely, (1) that normal and CLL B cell colony growth is helped by OKT4 cells; and (2) in contrast to immunoglobulin secretion by B cells, neither normal nor CLL OKT8 cells, unstimulated or activated by Con A, suppress B cell colony growth.     

Reduction of cerebral infarct volume by apocynin requires pretreatment and is absent in Nox2-deficient mice

Background and purpose:

Reactive oxygen species (ROS) derived from Nox2-containing reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity is reportedly detrimental in cerebrovascular disease. However, ROS generation by other Nox isoforms may have a physiological role. No Nox2-selective inhibitors have yet been identified, and thus it is unclear whether isoform non-selective Nox inhibitors would necessarily improve outcome after stroke. We assessed the effect of apocynin on cerebrovascular ROS production and also on outcome following cerebral ischaemia when administered either before ischaemia or after cerebral reperfusion. The involvement of Nox2-containing NADPH oxidase in the effects of apocynin was assessed using Nox2^−/− mice.

Experimental approach:

Transient cerebral ischaemia was induced by 0.5 h middle cerebral artery occlusion followed by 23.5 h reperfusion. Mice received apocynin (2.5 mg·kg⁻¹, i.p.) either 0.5 h before ischaemia or 1 h after reperfusion. In situ superoxide production after cerebral ischaemia-reperfusion was measured in brain sections of wild-type mice at 24 h using dihydroethidium fluorescence.

Key results:

Treatment with apocynin 0.5 h before ischaemia reduced total infarct volume, neurological impairment and mortality in wild-type but not Nox2^−/− mice. Conversely, treatment with apocynin 1 h after initiation of reperfusion had no protective effect. Cerebral ischaemia and reperfusion increased superoxide production in the brain at 24 h, and pretreatment but not posttreatment with apocynin reduced superoxide levels.

Conclusions and implications:

Apocynin improves outcome following stroke when administered before ischaemia in wild-type but not Nox2^−/− mice.     

Determining the date of diagnosis – is it a simple matter? The impact of different approaches to dating diagnosis on estimates of delayed care for ovarian cancer in UK primary care

Background  

Studies of cancer incidence and early management will increasingly draw on routine electronic patient records. However, data may be incomplete or inaccurate. We developed a generalisable strategy for investigating presenting symptoms and delays in diagnosis using ovarian cancer as an example.