Coronary flow regulation in mouse heart during hypercapnic acidosis: role of NO and its compensation during eNOS impairment

AIMS: This study addressed the hypotheses that the hypercapnic flow response in wild-type (WT) mouse heart is mainly mediated by nitric oxide (NO) and, thus, severely blunted in endothelial nitric oxide synthase knockout (eNOS-KO) mice and in WT mice after continuous pharmacological block (2 weeks) of NOS enzymes (WT-LN). METHODS AND RESULTS: Step changes of arterial pCO(2) were performed in isolated perfused hearts (n = 105). Contributions of NOS (L-NAME, TRIM), cyclooxygenase (indomethacin), epoxyeicosanotrienes (miconazole), adenosine A2A-receptors (SCH 58261), KV-channels (4-AP), KCa-channels (TEA), and K ATP-channels (glibenclamide) were studied in WT and eNOS-KO mouse hearts. Change of arterial pCO(2) increased coronary flow by 31.3 +/- 4% in WT, a response that was significantly decreased to 9.2 +/- 6% after L-NAME. Additional glibenclamide infusion (n = 5) completely abolished the steady-state flow increase during hypercapnic acidosis (-4.2 +/- 2.3%, P = 0.004 vs. control). Hearts from eNOS-KO mice as well as WT-LN showed a fully preserved flow response insensitive towards NOS-blockade. Whereas indomethacin, miconazole, TEA, and SCH 58261 were ineffective to reduce the flow response, glibenclamide blunted it in eNOS-KO hearts. CONCLUSION: NO-production and K ATP-channel activation together may fully account for the steady-state hypercapnic flow response in mouse heart. However, chronic deletion of eNOS does not result in a reduced hypercapnic flow response. Enhanced activation of K ATP-channels and potentially Kv-channels contributes to the compensatory mechanisms involved in the hypercapnic flow response when eNOS activity is absent.     

Wavelet analysis of cutaneous blood flow in melanocytic skin lesions

Laser Doppler flowmetry (LDF) is frequently used to study the microcirculation. Usually LDF time series are analyzed by conventional linear methods, mainly Fourier analysis. The aim of this study was to observe dynamic blood perfusion of the skin in malignant and benign melanocytic skin lesions. Wavelet transformation was performed on each LDF time series in order to calculate a vasomotion field. First, the differences in vasomotion between healthy and pigmented skin were evaluated visually on six different time scales of the vasomotion field. In order to quantify the findings, vasomotion scale variance (VSV) was calculated for each scale plane of the vasomotion field. These VSV were compared using contrast DeltaVSV to determine the difference between healthy skin and a pigmented skin lesion in the same patient. After the measurements, the skin lesions were excised and examined histologically. We found that wavelet analysis of LDF time series is a specific, sensitive method for the in vivo identification of malignant melanoma. It is a non-invasive procedure and takes minimal time to be carried out.     

<Emphasis Type="Italic">GSTP1</Emphasis> and <Emphasis Type="Italic">MDR1</Emphasis> Genotypes and Central Nervous System Relapse in Childhood Acute Lymphoblastic Leukemia

The probability of event-free survival of childhood acute lymphoblastic leukemia (ALL) approaches 80% or more with the use of modern multiagent chemotherapeutic regimens. One major contribution to this success has been reduction of the rate of central nervous system (CNS) relapses to less than 5%. However, heterogeneity is observed with regard to the incidence of CNS relapse in homogenously treated patient populations. One potential explanation for this heterogeneity is variation in the genetic background of these populations. Glutathione S-transferase P1 and P-glycoprotein are implicated in resistance to a variety of chemotherapeutic agents and have been localized to the blood-brain barrier. In a matched case-control study, we investigated the associations between CNS relapse in childhood ALL and the presence of phenotypically relevant single nucleotide polymorphisms within the GSTP1 (codon 105 and 114) and MDR1 genes (ABCB1; coding for Pgp; exon 26, C3435T). Significant reductions in risk of CNS relapse were observed for patients homozygous for the GSTP1 Val105 allele as well as for patients with the MDR1 3435T/T or C/T genotype. For both genotypes, the effect was restricted to patients at intermediate or high risk of treatment failure. These results suggested a modulating role for host genetic variation in the development of CNS relapse in childhood ALL treated according to Berlin-Frankfurt-Münster protocols.     

No difference in clinical progression between patients infected with the predominant human immunodeficiency virus type 1 circulating recombinant form (CRF) 02_AG strain and patients not infected with CRF02_AG,in Western and West-Central Africa: a four-year prospective multicenter study

To compare human immunodeficiency virus (HIV) type 1 disease progression in patients infected by the predominant strain circulating recombinant form (CRF) 02_AG in western and west-central Africa and in patients infected by other strains, a prospective multicenter cohort study was conducted in Cameroon and Senegal. Among the 335 patients, a broad HIV-1 group M subtype diversity was observed in the envelope V3-V5 region, but strain CRF02_AG predominated in both Cameroon and Senegal (61.2% and 62.9%, respectively; P<.8). Multivariate analyses showed no difference between patients infected by CRF02 strains and those infected by other strains in terms of survival (adjusted hazards ratio [HR], 1.16; 95% confidence interval [CI], 0.76-1.78; P=.5), clinical disease progression (HR, 0.79; 95% CI, 0.50-1.25; P=.3), or square root CD4 cell decline (regression coefficient, -0.01; 95% CI, -0.82 to 0.81; P=.9). This study suggests that the predominance of HIV-1 CRF02_AG strain in western and west-central Africa should have no major clinical consequences.     

Early versus late‐applied constraint‐induced movement therapy: A multisite,randomized controlled trial with a 12‐month follow‐up

Background and Purpose

A direct comparison between the effects of constraint‐induced movement therapy (CIMT) applied early after stroke and that of CIMT applied in the chronic phase has not been conducted. This study aimed to compare the long‐term effects of CIMT applied 6 months after stroke with the results of CIMT applied within 28 days post‐stroke.

Methods

This study was a single‐blinded, multicentre, randomized controlled trial with a crossover design. Forty‐seven patients received CIMT either early (within 28 days) or 6 months after stroke. Both groups received standard rehabilitation and were tested at 5 time points. The primary outcome measure was Wolf Motor Function Test (WMFT); the secondary measures were Nine‐Hole Peg Test (NHPT), the Fugl‐Meyer Assessment (FMA) of the upper extremity, Stroke Impact Scale, and Modified Rankin Scale (MRS).

Results

Compared with baseline data, both groups showed significant improvements in the primary and secondary outcome measures after 12 months. No significant differences between the 2 treatment groups were found before and after the delayed intervention group received CIMT at 6 months and during the 12‐month follow‐up. Both groups recovered considerably and showed only minor impairment (median FMA score of 64) after 6 months. The early intervention group showed an initially faster recovery curve of WMFT, NHPT, and MRS scores.

Discussion

In contrast to most CIMT studies, our study could not find an effect of CIMT applied 6 months after stroke. Our results indicate that commencing CIMT early is as good as delayed intervention in the long term, specifically in this group of patients who might have reached a ceiling effect during the first 6 months after stroke. Nevertheless, the early CIMT intervention group showed a faster recovery curve than the delayed intervention group, which can be a clinically important finding for patients in the acute phase.     

Empfehlungen zu Ernährung und Bewegung von Kleinkindern

Monatsschrift Kinderheilkunde -     

Ganciclovir-mediated elimination of HSV-Tk+ T cells and cure of graft-vs-host disease in an allogeneic bone marrow transplantation model in the rat

OBJECTIVE: Suicide gene therapy for leukemia aims to benefit from T cells in the BM graft, by reducing the probability of leukemia relapse (GVL), while severe complications of graft-vs-host disease (GVHD) may be avoided. In an allogeneic rat BMT model we defined the conditions to induce a lethal GVHD with HSV-Tk gene-transduced T cells. We studied the feasibility to rescue the animals by conditional elimination of the T cells with ganciclovir (GCV) treatment. METHODS: Allogeneic T cells transduced with a retroviral vector encoding the HSV-Tk suicide gene were added in varying numbers to a BM graft. Expression of HSV-Tk strongly increases the cytolytic effect of GCV, thereby allowing elimination of overreactive T cells at will. Various experimental conditions were tested in the rat model. RESULTS: A relation between the number of HSV-Tk(+) T cells added to the BM graft and GVHD development was found. GCV treatment resulted in selective HSV-Tk(+) T-cell elimination in blood and tissues but not in abrogation of GVHD due to persistence of HSV-Tk(-) T cells. T cells in unmanipulated rat BM normally have a low risk to induce GVH but when they are administered in combination with high numbers of HSV-Tk(+) T cells there is an apparent increase in their GVH-inducing potential. When HSV-Tk(+) T cells are added to T cell-depleted BM a consequently developing GVH can be controlled by GCV treatment with 60-70% of the animals surviving. CONCLUSIONS: We show that T cell-mediated suicide gene therapy within the context of allo-BMT can be applied with success. The apparent limitation in the number of transduced as well as nontransduced T cells that can be safely added to the BM graft should be taken into consideration when designing human suicide gene therapy protocols.     

Dendritic cells process synthetic long peptides better than whole protein,improving antigen presentation and T‐cell activation

The efficiency of antigen (Ag) processing by dendritic cells (DCs) is vital for the strength of the ensuing T‐cell responses. Previously, we and others have shown that in comparison to protein vaccines, vaccination with synthetic long peptides (SLPs) has shown more promising (pre‐)clinical results. Here, we studied the unknown mechanisms underlying the observed vaccine efficacy of SLPs. We report an in vitro processing analysis of SLPs for MHC class I and class II presentation by murine DCs and human monocyte‐derived DCs. Compared to protein, SLPs were rapidly and much more efficiently processed by DCs, resulting in an increased presentation to CD4⁺ and CD8⁺ T cells. The mechanism of access to MHC class I loading appeared to differ between the two forms of Ag. Whereas whole soluble protein Ag ended up largely in endolysosomes, SLPs were detected very rapidly outside the endolysosomes after internalization by DCs, followed by proteasome‐ and transporter associated with Ag processing‐dependent MHC class I presentation. Compared to the slower processing route taken by whole protein Ags, our results indicate that the efficient internalization of SLPs, accomplished by DCs but not by B or T cells and characterized by a different and faster intracellular routing, leads to enhanced CD8⁺ T‐cell activation.