Identification of CRKL as the constitutively phosphorylated 39-kD tyrosine phosphoprotein in chronic myelogenous leukemia cells

Chronic myelogenous leukemia (CML) is characterized by the presence of the Philadelphia (Ph) chromosome in clonally derived hematopoietic precursors and their progeny. The Ph chromosome arises from a translocation that deregulates the c-ABL protein tyrosine kinase, giving it transforming potential and increased kinase activity. We observed a unique 39-kD tyrosine phosphoprotein (pp39), previously reported in blastic CML cell lines, in neutrophils from 50 cases of chronic phase CML. This protein was prominently and constitutively tyrosine-phosphorylated in CML neutrophils and was not phosphorylated in normal neutrophils. Stimulation of normal neutrophils with cytokines and agonists did not induce tyrosine phosphorylation of proteins migrating in the region of pp39, and the phosphorylation state of pp39 in CML neutrophils was not affected by kinase inhibitors known to downregulate the ABL kinase. The pp39 was not phosphorylated in hematopoietic cells from healthy donors or from patients with Ph chromosome-negative myeloproliferative disorders. Using micro amino acid sequencing of purified preparations of pp39, we identified pp39 as CRKL protein, which is consistent with recent immunologic studies in the blastic K562 cell line. Immunoblotting with anti-CRKL antibodies showed the presence of CRKL protein in CML cells and cell lines as well as in antiphosphotyrosine immunoprecipitates from CML cells. Our results suggest that pp39 CRKL in CML neutrophils may be stably tyrosine-phosphorylated by the BCR/ABL kinase at an early stage of myeloid differentiation when the ABL kinase is active. CRK, CRKL, and other SH2 (SRC homology domain)/SH3-containing proteins function as adaptor molecules in nonreceptor tyrosine kinase signalling pathways. Although the CRKL protein is present in normal neutrophils, it is not tyrosine-phosphorylated, and the inability to induce such phosphorylation in normal neutrophils suggests a special role of this phosphoprotein in the pathogenesis of CML. Constitutive phosphorylation of CRKL is unique to CML, indicating that it may be a useful target for therapeutic intervention.     

Serological confirmation of human T-lymphotropic virus type I infection in healthy blood and plasma donors

We wished to develop criteria for serological confirmation of human T- lymphotropic virus type I (HTLV-I) infection in healthy donors. Selected serum or plasma samples reactive by HTLV-I enzyme immunosorbent assay or gel-agglutination assays with at least one viral- specific band on Western immunoblot (WIB) were tested in six laboratories by four WIBs and four radioimmunoprecipitation assays (RIPAs) for antibodies to HTLV-I proteins encoded by gag (p19 and p24), env (gp46 and/or gp61), and tax (p40x) genes. One hundred forty-two donor sera were obtained from 38 Japanese, 69 American, and 35 Caribbean blood or plasma donors. Among these samples, WIB assays appeared more sensitive to p24 antibodies, whereas RIPAs were significantly more sensitive to gp61 antibodies. All sera (137) with gp61 antibodies had p24 antibodies. Of the 137 sera positive for p24 and gp61 antibodies, p19 antibodies were detected in 129 sera, and p40x antibodies were detected in 108. In sera with p19 antibodies and antibodies to env- or tax-encoded proteins, p24 antibodies were always present. Antibodies to p40x were not found in the absence of gp61 antibodies. Virological evidence of infection was found in seven American donors by lymphocyte coculture (one HTLV-I, one HTLV-II) or by polymerase chain reaction (three HTLV-I, two HTLV-II). Sera from all seven donors showed p24 and gp46 and/or gp61 antibodies. We suggest that seroreactivity to both p24 and gp46 and/or gp61 by WIB or RIPA or both are suitable criteria to confirm but not to distinguish HTLV-I and HTLV-II infections.     

Congenital polycythemias/erythrocytoses

Congenital polycythemias may result from inherited defects in hypoxia sensing, from inherited intrinsic defects in red blood cell precursors, or from inherited conditions that cause low tissue oxygen tension and secondary polycythemia. Conditions of defective hypoxia sensing feature inappropriately normal or elevated serum erythropoietin (Epo) concentrations in the setting of normoxia and erythrocytosis. They are often due to homozygous or compound heterozygous germline mutations in the von Hippel Lindau tumor suppressor gene (VHL) but without increased incidence of tumors. Affected persons have a high risk of arterial thrombosis and early mortality. The molecular biology of rare polycythemic patients with a single mutated VHL allele remains obscure. Primary congenital and familial polycythemias are characterized by low Epo levels and increased erythroid precursor responsiveness to Epo. They are often due to heterozygous gain-of function mutations in the gene for erythropoietin receptor (EPOR). Secondary congenital polycythemias have low tissue oxygen tension due to hemoglobins with high affinity for oxygen, low erythrocyte 2,3 biphosphoglycerate levels, methemoglobinemia or cyanotic heart or lung disease. Whether phlebotomy therapy reduces complications and prolongs survival in congenital polycythemia is not known.     

Fatigue, muscle strength and vitamin D status in women with systemic lupus erythematosus compared with healthy controls

Recent studies have demonstrated an inverse relationship between vitamin D levels and fatigue in systemic lupus erythematosus (SLE). The aims of this study were to evaluate proximal muscle strength, fatigue and vitamin D levels in women with SLE compared with healthy controls and to investigate relationships between these factors in a cohort of women with SLE. Forty-five women (24 SLE, 21 healthy controls) participated. Primary outcome measures were the fatigue severity scale (FSS), isometric muscle strength of dominant limbs using hand held dynamometry, two functional tests--the 30-second chair stand test and the 1-kg arm lift test, with vitamin D status measured using 25(OH)D. Overall 25(OH)D levels were 68.4 (22.4) nmol/L with no difference between SLE and control groups. There was a statistically and clinically significant difference in fatigue, 1-kg arm lift, 30-second sit to stand, knee extension, hip flexion, hip abduction, shoulder flexion and grip strength in the SLE group compared with the control group (p < 0.05). In the SLE group FSS was moderately correlated with both functional measures (1-kg arm lift r = -0.42, 30-second chair stand r = -0.44, p < 0.05). However, no statistically significant correlation between dynamometry measures and fatigue was evident. There was no association between fatigue and 25(OH)D level (r = -0.12). In summary, women with SLE were weaker and demonstrated reduced physical function and higher fatigue levels than healthy controls. Fatigue was related to physical function but not vitamin D status or maximal isometric strength in vitamin D replete individuals with SLE.     

CLIMACTERIC SYMPTOMS IN HEALTHY MIDDLE-AGED WOMEN

SUMMARY The incidence of climacteric symptoms was determined in 247 healthy premenopausal women in a community setting. These volunteers had been recruited to a longitudinal study of bone density. Of these subjects, 46 ceased to menstruate during the study, and in this subgroup symptoms were compared before and after cessation of menstruation. Only hot flushes increased after cessation of menstruation in the longitudinal study and showed age correlation in the cross-sectional study. Hot flushes thus emerged as a true menopausal symptom. Although evidence for this is weaker, cold sweats and suffocation seem likely to be genuinely menopausal. Breast discomfort and the four mood symptoms of irritability, excitability, depression and poor concentration improved after cessation of menstruation, and this study gives no support for their being part of the menopausal syndrome; it suggests that these symptoms are more likely to be related to menstruation than to the menopause.     

A review of campfire burns in children: The QLD experience

Introduction

Campfire burns in children are a significant health issue. It is imperative that the extent of the problem is examined and strategies discussed to inform future prevention campaigns.

期刊俱乐部和病例讨论会改变医生临床实践的效果

作为互动性很强的小组学习形式,目前还不清楚期刊俱乐部和病例讨论会形式的继续医学教育活动是否能与传统的继续医学教育活动一样,帮助医生改变临床实践水平.为此,美国科罗拉多医疗公司进行了一项观察性研究,以确定期刊俱乐部和病例讨论会形式的继续医学教育活动的效果.     

新型输送型球囊扩张导管在颅内动脉狭窄治疗中的临床应用研究

目的：探讨新型输送型球囊扩张导管(Fastunnel)在颅内动脉粥样硬化狭窄介入治疗中的应用效果。方法：2021年11月至2022年2月,我们使用新型输送型球囊扩张导管对10例颅内动脉粥样硬化狭窄的患者进行了球囊扩张+支架成形术。收集并分析了患者的基线情况、影像学特点、治疗情况及围手术期情况。结果：男6例,女性4例,平均年龄(62.7±6.7)岁。10例患者均成功接受手术治疗,手术时长为16~65(37.3±18.2)min,治疗过程所受辐射剂量为1381~4901(2643.7±1131.7)mGy,剂量面积乘积(DAP)值为5707~38112(17526.8±10809.5)μGym₂^。围手术期无出血及缺血相关并发症。结论：输送型球囊扩张导管具有较好的安全性,能有效地简化手术步骤、缩短手术时间,对减少患者及医生所受射线剂量。