Characterization of primitive subpopulations of normal and leukemic cells present in the blood of patients with newly diagnosed as well as established chronic myeloid leukemia

Elevated numbers of primitive Philadelphia chromosome-positive (Ph+) progenitors, including long-term culture-initiating cells (LTC-IC) as well as colony-forming cells (CFC), have been previously described in the blood of patients with chronic myeloid leukemia (CML) in chronic phase with high white blood cell counts. In the present study, which focused primarily on an analysis of circulating progenitors present in such patients at diagnosis, we discovered the frequent and occasionally exclusive presence of circulating normal (Ph-) LTC-IC, often at levels above those seen for LTC-IC in the blood of normal individuals. The presence of detectable numbers of circulating Ph- LTC-IC was independent of the fact that the same peripheral blood samples also contained elevated numbers of predominantly or exclusively Ph+ CFC. Interestingly, both the Ph+ and Ph- LTC-IC in these samples were CD34+CD71- and variably CD38- and Thy-1+, as previously documented for LTC-IC in normal marrow. Thus, neither CD38 nor Thy-1 expression was useful for discriminating between Ph+ and Ph- LTC-IC in mixed populations. Nevertheless, an association of these phenotypes with LTC- IC function did allow highly enriched (> 5% pure) suspensions of either Ph+ or Ph- LTC-IC to be obtained from selected samples of CML blood in which the initial LTC-IC population was either predominantly Ph+ or Ph- , respectively. These findings suggest that the mechanisms causing mobilization of leukemic stem cells in untreated CML patients may affect their normal counterparts. They also indicate a possible new source of autologous cells for the support of intensive therapy of CML patients. Finally, they provide a method for obtaining the most highly purified populations of Ph+ LTC-IC described to date. This method should be useful for further analyses of the molecular activities of these very primitive neoplastic cells.     

Two-decade-long trends (1975-1997) in the incidence,hospitalization, and long-term death rates associated with complete heart block complicating acute myocardial infarction: a community-wide perspective

Background The purpose of this community-wide study was to describe a >2-decade-long experience (1975-97) in the incidence and death rates associated with complete heart block (CHB) in patients with acute myocardial infarction (AMI). Limited population-based data exist describing recent, and changes with time therein, incidence and case-fatality rates associated with CHB complicating AMI. Methods We conducted an observational study of 9082 metropolitan Worcester, Mass, residents (1990 census = 437,000) hospitalized with validated AMI in all greater Worcester hospitals during 11 1-year periods between 1975 and 1997. Results Overall, CHB developed in 5.0% of patients with AMI. The incidence rates of CHB declined in the periods studied (6.0% in 1975/78 vs 3.1% in 1997). Declines in the occurrence of CHB were noted in patients with anterior or inferior/posterior MI. These trends remained after adjustment for other factors that might affect the risk of CHB. Patients in whom CHB developed experienced significantly higher hospital death rates than patients in whom CHB did not develop (46.8% vs 14.6%). However, improving trends in the hospital survival rate of patients with CHB were observed between 1975/78 (47.4% surviving) and 1997 (61.3% surviving). Patients in whom CHB developed during hospitalization were not at increased risk for dying after hospital discharge. Conclusions Our findings indicate that the incidence of CHB complicating AMI has declined with time. The hospital prognosis of patients in whom CHB developed has improved, but these patients remain at an increased risk of hospital mortality. The long-term prognosis of patients with inferior MI and CHB is similar to that of patients in whom CHB did not develop. Patients with anterior MI and CHB may be at an increased risk of long-term mortality. (Am Heart J 2003;145:500-7.)     

Copy number variants in patients with short stature

Height is a highly heritable and classic polygenic trait. Recent genome-wide association studies (GWAS) have revealed that at least 180 genetic variants influence adult height. However, these variants explain only about 10% of the phenotypic variation in height. Genetic analysis of short individuals can lead to the discovery of novel rare gene defects with a large effect on growth. In an effort to identify novel genes associated with short stature, genome-wide analysis for copy number variants (CNVs), using single-nucleotide polymorphism arrays, in 162 patients (149 families) with short stature was performed. Segregation analysis was performed if possible, and genes in CNVs were compared with information from GWAS, gene expression in rodents'' growth plates and published information. CNVs were detected in 40 families. In six families, a known cause of short stature was found (SHOX deletion or duplication, IGF1R deletion), in two combined with a de novo potentially pathogenic CNV. Thirty-three families had one or more potentially pathogenic CNVs (n=40). In 24 of these families, segregation analysis could be performed, identifying three de novo CNVs and nine CNVs segregating with short stature. Four were located near loci associated with height in GWAS (ADAMTS17, TULP4, PRKG2/BMP3 and PAPPA). Besides six CNVs known to be causative for short stature, 40 CNVs with possible pathogenicity were identified. Segregation studies and bioinformatics analysis suggested various potential candidate genes.     

A 3-base pair deletion,c.9711_9713del,in DMD results in intellectual disability without muscular dystrophy

We have identified a deletion of 3 base pairs in the dystrophin gene (DMD), c.9711_9713del, in a family with nonspecific X-linked intellectual disability (ID) by sequencing of the exons of 86 known X-linked ID genes. This in-frame deletion results in the deletion of a single-amino-acid residue, Leu3238, in the brain-specific isoform Dp71 of dystrophin. Linkage analysis supported causality as the mutation was present in the 7.6 cM linkage interval on Xp22.11–Xp21.1 with a maximum positive LOD score of 2.41 (MRX85 locus). Molecular modeling predicts that the p.(Leu3238del) deletion results in the destabilization of the C-terminal domain of dystrophin and hence reduces the ability to interact with β-dystroglycan. Correspondingly, Dp71 protein levels in lymphoblastoid cells from the index patient are 6.7-fold lower than those in control cell lines (P=0.08). Subsequent determination of the creatine kinase levels in blood of the index patient showed a mild but significant elevation in serum creatine kinase, which is in line with impaired dystrophin function. In conclusion, we have identified the first DMD mutation in Dp71 that results in ID without muscular dystrophy.     

Individual and Composite Study Endpoints: Separating the Wheat from the Chaff

We provide an overview of the individual and combined clinical endpoints and patient-reported outcomes typically used in clinical trials and prospective epidemiological investigations. We discuss the strengths and limitations associated with the utilization of aggregated study endpoints and surrogate measures of important clinical endpoints and patient-centered outcomes. We hope that the points raised in this overview will lead to the collection of clinically rich, relevant, measurable, and cost-efficient study outcomes.     

Changing clinico-laboratory profile of encephalitis patients in the eastern Uttar Pradesh region of India

A cross-sectional study was done on 100 consecutive paediatric patients presenting with acute encephalitis syndrome. The clinico-laboratory features of all patients were recorded in a prestructured performa. Cerebrospinal fluid and serum samples were tested for: Japanese encephalitis (JE) virus; Chandipura virus; coxsackie virus; dengue virus; enterovirus 76; and West Nile virus. Twenty-two (22.0%) patients were confirmed JE cases and 17% had parasitic or bacteriological aetiology. The remaining 61 cases (61.0%) in which no viral aetiological agent was found were grouped as non-JE cases. Peripheral vascular failure, splenomegaly and hypotonia were distinguishing clinical features found in the non-JE patients. A high mortality of 26.5% was seen in patients with confirmed or presumptive viral encephalitis (22/83). A fatal outcome was independently associated with peripheral vascular failure and pallor at the time of admission. Early recognition of these signs may help clinicians to manage these cases.