Antinociceptive activity of NK1 receptor antagonists: non-specific effects of racemic RP67580.

1. Release of substance P in the dorsal horn is considered a primary event in the perception of pain. The profile of racemic RP67580, a non-peptide antagonist at the NK1 (substance P) receptor, was examined in a range of antinociception tests on rodents. 2. At doses up to 30 mg kg-1, s.c. racemic RP67580 exhibited antinociceptive activity in writhing and formalin paw tests in mice and gerbils. Acetic acid induced writhing and the licking response to formalin were reduced to 40-50% of the level observed in vehicle-treated animals (P < 0.05). However, this agent was not active in mouse tail flick, rat paw pressure or rat and guinea-pig formalin paw tests. 3. Like racemic RP67580, the calcium channel blockers nifedipine (30 mg kg-1, i.p.) and verapamil (10 or 20 mg kg-1, s.c.) inhibited the response to formalin by approximately 60% in gerbils (P < 0.05 compared with vehicle-treated animals). 4. Evidence for calcium channel antagonist activity of RP67580 was obtained in vitro. Racemic RP67580 inhibited calcium entry into depolarized strips of guinea-pig ileum longitudinal muscle myenteric plexus (apparent KB = 587 +/- 115 nM), inhibited [3H]-diltiazem binding to rabbit skeletal membranes (IC50 = 298 nM) and depressed high threshold calcium currents in neurones cultured from rat cortex (10% inhibition at 10 microM). 5. These findings indicate that the acute antinociceptive effects of RP67580 may not be attributable to a specific interaction with NK1 receptors and may be mediated via calcium channel blockade.     

Postradiation sensitization of the histone deacetylase inhibitor valproic acid

PURPOSE: Preclinical studies evaluating histone deacetylase (HDAC) inhibitor-induced radiosensitization have largely focused on the preirradiation setting based on the assumption that enhanced radiosensitivity was mediated by changes in gene expression. Our previous investigations identified maximal radiosensitization when cells were exposed to HDAC inhibitors in both the preradiation and postradiation setting. We now expand on these studies to determine whether postirradiation exposure alone affects radiosensitivity. EXPERIMENTAL DESIGN: The effects of the HDAC inhibitor valproic acid (VA) on postirradiation sensitivity in human glioma cell lines were evaluated using a clonogenic assay, exposing cells to VA up to 24 h after irradiation. DNA damage repair was evaluated using gammaH2AX and 53BP1 foci and cell cycle phase distribution was analyzed by flow cytometry. Western blot of acetylated gammaH2AX was done following histone extraction on AUT gels. RESULTS: VA enhanced radiosensitivity when delivered up to 24 h after irradiation. Cells accumulated in G(2)-M following irradiation, although they returned to baseline at 24 h, mitigating the role of cell cycle redistribution in postirradiation sensitization by VA. At 12 h after irradiation, significant gammaH2AX and 53BP1 foci dispersal was shown in the control, although cells exposed to VA after irradiation maintained foci expression. VA alone had no effect on the acetylation or phosphorylation of H2AX, although it did acetylate radiation-induced gammaH2AX. CONCLUSIONS: These results indicate that VA enhances radiosensitivity at times up to 24 h after irradiation, which has direct clinical application.     

Development of treatment and clinical results in childhood acute myeloid leukemia in the Czech Republic

Purpose

Treatment of childhood acute myeloid leukemia (AML) was unified in the year 1993 according to acute myeloid leukemia-Berlin–Frankfurt–Munster (AML-BFM) protocols in the Czech Republic. We evaluated data on clinical and therapeutic results in children with AML treated in three subsequent trials, comparing two periods, June 1993 to February 2004 (AML-BFM 93 and 98) vs. March 2004 to December 2009 (AML-BFM 2004 trial).

Patients and methods

Data of 182 eligible patients were analyzed, 125 in AML-BFM 93 and 98 trials, and 57 in AML-BFM 2004 trial enrolled prior to December 2009. Down syndrome patients were excluded from analysis.

Results

In studies AML-BFM 93 and 98, 79.2 % of 125 patients achieved complete remission (CR), 19 patients (15.2 %) suffered from early death, 7 (5.6 %) were nonresponders, 33 (33.3 %) relapsed, 12 (12.1 %) died in CR, and 2 patients (2.0 %) developed secondary malignancy. The estimated probability of event-free survival (pEFS) at 5 years was 41.6 %, the overall survival (OS) at 5 years was 46.4 %. In AML-BFM 2004 trial, 93 % of 57 patients attained CR, 3 patients (5.2 %) suffered from early death, 1 (1.8 %) was nonresponder, 16 (30.2 %) relapsed, 2 (3.8 %) died in CR, and 2 patients (3.5 %) developed secondary malignancy. The estimated pEFS at 5 years was 56.1 %, 5-years overall survival (5y-OS) was 73.7 %.

Conclusion

Gradual improvement of CR rate and OS together with decreasing incidence of toxic deaths in AML patients were achieved because of gain of experience with very intensive modern treatment centralized in a limited number of institutions.     

Exposures of Sus scrofa to a TASER® conducted electrical weapon: no effects on 2-dimensional gel electrophoresis patterns of plasma proteins

In an earlier study, we found significant changes in red-blood-cell, leukocyte, and platelet counts, and in red-blood-cell membrane proteins, following exposures of anesthetized pigs to a conducted electrical weapon. In the current study, we examined potential changes in plasma proteins [analyzed via two-dimensional gel electrophoresis (2-DGE)] following two 30 s exposures of anesthetized pigs (Sus scrofa) to a TASER ^® C2 conducted electrical weapon. Patterns of proteins, separated by 2-DGE, were consistent and reproducible between animals and between times of sampling. We determined that the blood plasma collection, handling, storage, and processing techniques we used are suitable for swine blood. There were no statistically significant changes in plasma proteins following the conducted-electrical-weapon exposures. Overall gel patterns of fibrinogen were similar to results of other studies of both pigs and humans (in control settings, not exposed to conducted electrical weapons). The lack of significant changes in plasma proteins may be added to the body of evidence regarding relative safety of TASER C2 device exposures.     

Survivors of acute respiratory distress syndrome: relationship between pulmonary dysfunction and long-term health-related quality of life

BACKGROUND: Patients who survive acute respiratory distress syndrome (ARDS) often report decreased general health-related quality of life (HRQOL) following hospital discharge. The extent to which this impairment is due to pulmonary or nonpulmonary causes is unclear. We describe the pattern of recovery of patients surviving ARDS to illuminate any relationships between lung spirometry values, pulmonary symptoms, and overall HRQOL. METHODS: Seventy-three survivors of ARDS were enrolled in a 12-month follow-up study as part of a phase III randomized, multicenter trial. Patients were contacted at 3, 6, and 12 months after enrollment to complete generic and disease-specific HRQOL questionnaires and have lung spirometry tests performed. RESULTS: For all domains of the Medical Outcomes Study Short Form-36 (SF-36) and the St. George's Respiratory Questionnaire (SGRQ) at all time intervals, survivors of ARDS had significantly lower scores than age- and sex-matched population values. Over the 12-month follow-up period, we observed significant improvements to the overall Physical Component Score, but the Mental Component Score of the SF-36 and the SGRQ scores were not statistically different. Physical performance measures suggested that by 12 months, 57% had not returned to "normal activity." At 12 months, lung spirometry tests demonstrated mild abnormalities that were stable over time (64% and 49% had <80% predicted forced expiratory volume in 1 sec [Fev1] and forced vital capacity [Fvc], respectively). At 12 months, the forced expiratory volume in 1 sec correlated strongly with the physical function domain of the SF-36 (correlation coefficient = 0.601; p < .01) and moderately with all domains of the SGRQ (correlation coefficient = -0.36, -50; p < .01 in all cases). In addition, there were several strong to moderate correlations between the various domains of the SF-36 and SGRQ. CONCLUSIONS: Survivors of ARDS have considerable respiratory symptoms and reduced HRQOL that is still prevalent at 12 mos following onset of injury. There are significant correlations between lung spirometry, pulmonary symptoms, and overall HRQOL, thus suggesting the acute lung injury/ARDS is causally contributing to the observed long-term outcome.     

Minimal residual disease in peripheral blood at day 15 identifies a subgroup of childhood B-cell precursor acute lymphoblastic leukemia with superior prognosis

Background

Most minimal residual disease-directed treatment interventions in current treatment protocols for acute lymphoblastic leukemia are based on bone marrow testing, which is a consequence of previous studies showing the superiority of bone marrow over peripheral blood as an investigational material. Those studies typically did not explore the prognostic impact of peripheral blood involvement and lacked samples from very early time points of induction.

Design and Methods

In this study, we employed real-time quantitative polymerase chain reaction analysis to examine minimal residual disease in 398 pairs of blood and bone marrow follow-up samples taken from 95 children with B-cell precursor acute lymphoblastic leukemia treated with the ALL IC-BFM 2002 protocol.

Results

We confirmed the previously published poor correlation between minimal residual disease in blood and marrow at early treatment time points, with levels in bone marrow being higher than in blood in most samples (median 7.9-fold, range 0.04–8,293-fold). A greater involvement of peripheral blood at diagnosis was associated with a higher white blood cell count at diagnosis (P=0.003) and with enlargement of the spleen (P=0.0004) and liver (P=0.05). At day 15, a level of minimal residual disease in blood lower than 10⁻⁴ was associated with an excellent 5-year relapse-free survival in 78 investigated patients (100% versus 69±7%; P=0.0003). Subgroups defined by the level of minimal residual disease in blood at day 15 (high-risk: ≥10⁻², intermediate-risk: <10⁻² and ≥10⁻⁴, standard-risk: <10⁻⁴) partially correlated with bone marrow-based stratification described previously, but the risk groups did not match completely. No other time point analyses were predictive of outcome in peripheral blood, except for a weak association at day 8.

Conclusions

Minimal residual disease in peripheral blood at day 15 identified a large group of patients with an excellent prognosis and added prognostic information to the risk stratification based on minimal residual disease at day 33 and week 12.     

DQA103 subtypes have different associations with DRB1 and DQB1 alleles

Polymorphisms outside the hypervariable regions of HLA class II alleles that do not affect the peptide-binding site are probably not under selective pressure and could therefore be useful as markers of the evolutionary pathways of the HLA class II haplotypes. We have analyzed such a polymorphism in the variants of DQA1^*03, which differ at residue 160 encoded in exon 3. Our study included homozygous BCLs of the 10th IHWS and samples of a multiracial panel of 723 unrelated subjects which were also typed for allelic variations in exon 2 by hybridization with SSOP. BCLs having DQA1^*03 and 131 selected DQA1^*03-positive samples were typed for the dimorphism in exon 3 that distinguishes DQA1^*0301 and DQA1^*0302. DQA1^*0301 was found to be exclusively associated with DQB1^*0302, while samples carrying DQB1^*0201, 0301, 0303, and 0401 always had DQA1^*0302. A few haplotypes carrying DQB1^*0302 had DQA1^*0302. The fact that DQA1^*0301 is completely included in DQB1^*0302, and not vice versa, suggests that DQA1^*0301 may have arisen from a mutation in a haplotype containing DQA1^*0302-DQB1^*0302. DQB1^*0302 was found to be associated with all DR4 subtypes, suggesting possibly that the current variants of DRB1-DR4 may be of more recent origin. DRB1^*0405 was the only subtype of DR4 which was not associated with DQA1^*0301 and had multiple associations with the DQB1 alleles, therefore, perhaps representing the oldest allele of this group.     

St. Louis encephalitis and the substantia nigra: MR imaging evaluation.

Neuroimaging findings in cases of St. Louis encephalitis (StLE) have yet to be reported despite the relatively high frequency of this entity. An epidemic permitted the documentation of isolated hyperintensity of the substantia nigra on T2-weighted images in two patients with StLE. This distribution of MR imaging abnormality in cases of StLE mirrors the reports presented in the literature that implicate the substantia nigra as peculiarly susceptible to the StLE virus. Isolated lesions of the substantia nigra revealed by T2-weighted imaging should suggest the possibility of StLE.     

MicroRNA-650 expression is influenced by immunoglobulin gene rearrangement and affects the biology of chronic lymphocytic leukemia

MicroRNAs (miRNAs) play a key role in chronic lymphocytic leukemia as well as in normal B cells. Notably, miRNA gene encoding miR-650 and its homologs overlap with several variable (V) subgenes coding for lambda immunoglobulin (IgLλ). Recent studies describe the role of miR-650 in solid tumors, but its role in chronic lymphocytic leukemia (CLL) has not yet been studied. Our experiments demonstrate that miR-650 expression is regulated by coupled expression with its host gene for IgLλ. This coupling provides a unique yet unobserved mechanism for microRNA gene regulation. We determine that higher expression of miR-650 is associated with a favorable CLL prognosis and influences the proliferation capacity of B cells. We also establish that in B cells, miR-650 targets proteins important in cell proliferation and survival: cyclin dependent kinase 1 (CDK1), inhibitor of growth 4 (ING4), and early B-cell factor 3 (EBF3). This study underscores the importance of miR-650 in CLL biology and normal B-cell physiology.