PCR-positivity in harvested bone marrow predicts relapse after transplantation with autologous purged bone marrow in children in second remission of precursor B-cell acute leukaemia

Purging of autologous bone marrow (BM) grafts of children in second remission after a relapse of precursor B acute lymphoblastic leukaemia (ALL) in the BM has been carried out in our laboratory since 1987, initially by complement mediated cell lysis. This protocol was extended by performing an immunorosette depletion before lysis with complement. The aim of the present study was to assess by polymerase chain reaction the presence of residual leukaemic cells in the BM grafts before and after purging. The results were then correlated to clinical outcome. In 24/28 patients a PCR product was obtained by amplification of IgH and/or TcR junctional regions. BM before purging was available for analysis in 13 patients. We found that leukaemic cells could be detected in 8/13 (62%) of these grafts before purging . All these eight patients experienced a relapse, regardless of whether the purging procedure had been successful (defined as achievement of PCR-negativity) or not. In contrast, none of the five patients with PCR-negative grafts before purging relapsed ( P  = 0.0008). One patient died due to transplant-related toxicity. Of the remaining 23 patients, nine patients received a PCR-positive BM graft after purging. All these nine patients experienced a relapse as compared to 6/14 whose BM was PCR-negative after purging ( P  = 0.0072). Two of eight PCR-positive BM grafts could be purged to PCR-negativity. Thus, improvements both in treatment of leukaemia and in purging efficacy are still needed.     

Asthma symptom perception and obesity in children

This study examined the relationship between obesity and asthma symptom perception in 200 youth with asthma. Repeated subjective and objective peak flow measurements were summarized using the Asthma Risk Grid (Klein et al., 2004), resulting in Accurate, Symptom Magnification and Danger Zone scores. Analyses were stratified by age and included ethnicity.For younger children, obesity was not significantly related to perception scores. For older children, a significant obesity-by-ethnicity interaction for Accurate Symptom Perception scores indicated that obese white children had lower accuracy than white nonobese children, while there was no difference for obese versus nonobese minority children. Obesity was also related to higher Symptom Magnification scores regardless of ethnicity for older children.These findings suggest that obesity may complicate asthma management by interfering with the ability to accurately perceive symptoms for some patients. More remains to be learned about the role of sociodemographic factors underlying this relationship.     

MR shoulder arthrography in patients younger than 40 years of age: Frequency of rotator cuff tear versus labroligamentous pathology

The purpose of this study was to compare the frequency of rotator cuff pathology versus labroligamentous pathology in patients younger than 40 years and to determine whether routine MR arthrography is justified in all patients in this age group, regardless of the clinical symptoms. The MR arthrography was carried out on 332 patients 40 years of age and younger. Two hundred and forty‐three patients had clinical history of instability and possible labroligamentous pathology. Eighty‐nine patients had no history or physical signs of instability and were referred for reasons other than instability, such as assessment for rotator cuff tear. In the 243 patients younger than 40 years with clinical history of potential labral pathology, 39% (95/243) showed a labral tear and 2.1% (5/243) had a full‐thickness rotator cuff tendon tear. In the 89 patients with no history suggesting labral pathology, 19% (17/89) showed an unsuspected labral tear and 4.5% (4/89) had a full‐thickness rotator cuff tear. These findings suggest that, regardless of the clinical indication for referral, patients aged 40 and less referred for shoulder MRI should be imaged using MR arthrography because of the significant risk that symptoms are related to unsuspected labral pathology.     

Approaches in the understanding of morbillivirus neurovirulence

Certain members of the morbillivirus genus, canine distemper virus, phocine distemper virus, and the cetacean viruses of dolphins and porpoises exhibit high levels of central nervous system (CNS) infection in their natural hosts. CNS complications are rare for measles virus (MV) and are not associated with rinderpest virus (RPV) and peste des petits ruminants virus (PPRV) infection. However, both RPV and PPRV are neurovirulent in permissive murine strains. Human postmortem tissue, neural cell cultures, and animal models have been used to answer major questions concerning morbillivirus neurovirulence. Studies of the MV CNS complication subacute sclerosing panencephalitis (SSPE) indicate that virus could enter the CNS either by direct infection of endothelial cells or in infected leucocytes, followed by infection of predominately neurones and oligodendrocytes. It has been established that MV neurovirulence in mice is partially determined by the virus-receptor specificity. The two known MV receptors, CD46 and SLAM, have been examined in normal and SSPE brain tissue and the findings suggest that further receptors may be necessary to explain infection of the CNS with wild-type strains of MV. In both humans and mice (and in vitro), once infection of neurones has been established, virus spreads transneuronally. It is possible that all morbilliviruses transiently infect the CNS in their natural hosts, but development of disease is dependent on the efficiency of the immune response. Alternatively, for RPV and PPRV, virus entry may be restricted due either to absence of viral receptors or failure of virus to replicate or spread in the CNS.     

Increased uncoupling protein-2 levels in beta-cells are associated with impaired glucose-stimulated insulin secretion: mechanism of action

In pancreatic beta-cells, glucose metabolism signals insulin secretion by altering the cellular array of messenger molecules. ATP is particularly important, given its role in regulating cation channel activity, exocytosis, and events dependent upon its hydrolysis. Uncoupling protein (UCP)-2 is proposed to catalyze a mitochondrial inner-membrane H(+) leak that bypasses ATP synthase, thereby reducing cellular ATP content. Previously, we showed that overexpression of UCP-2 suppressed glucose-stimulated insulin secretion (GSIS) in isolated islets (1). The aim of this study was to identify downstream consequences of UCP-2 overexpression and to determine whether insufficient insulin secretion in a diabetic model was correlated with increased endogenous UCP-2 expression. In isolated islets from normal rats, the degree to which GSIS was suppressed was inversely correlated with the amount of UCP-2 expression induced. Depolarizing the islets with KCl or inhibiting ATP-dependent K(+) (K(ATP)) channels with glybenclamide elicited similar insulin secretion in control and UCP-2-overexpressing islets. The glucose-stimulated mitochondrial membrane ((m)) hyperpolarization was reduced in beta-cells overexpressing UCP-2. ATP content of UCP-2-induced islets was reduced by 50%, and there was no change in the efflux of Rb(+) at high versus low glucose concentrations, suggesting that low ATP led to reduced glucose-induced depolarization, thereby causing reduced insulin secretion. Sprague-Dawley rats fed a diet with 40% fat for 3 weeks were glucose intolerant, and in vitro insulin secretion at high glucose was only increased 8.5-fold over basal, compared with 28-fold in control rats. Islet UCP-2 mRNA expression was increased twofold. These studies provide further strong evidence that UCP-2 is an important negative regulator of beta-cell insulin secretion and demonstrate that reduced (m) and increased activity of K(ATP) channels are mechanisms by which UCP-2-mediated effects are mediated. These studies also raise the possibility that a pathological upregulation of UCP-2 expression in the prediabetic state could contribute to the loss of glucose responsiveness observed in obesity-related type 2 diabetes in humans.