Expression of the three nitric oxide synthase isoforms and nitric oxide level in the rat heart during cold storage and blood reperfusion

Maintenance of nitric oxide (NO) homeostasis is an important concept for myocardial protection. Here, we have investigated the NO pathway by analysing total nitrate concentration (NOx) and NO synthase (NOS) isoforms expression as well as the myocardial integrity by lactate dehydrogenase and creatine kinase contents in the rat heart graft arrested by CRMBM solution, submitted to 3 hr cold ischemia in the same solution and 24 hr blood reperfusion following heterotopic abdominal heart transplantation. NOx level was similar to baseline value after ischemia and significantly increased after 24 hr reperfusion. NOS isoforms expression was highly modulated after cold ischemia followed by blood reperfusion. Endothelial NOS expression was decreased after ischemia but restored after 24 hr reperfusion. Neuronal NOS expression was drastically decreased after ischemia and 24 hr reperfusion. Inducible NOS protein was present only after 24 hr reperfusion. Cold ischemia induced a severe loss of creatine kinase without any modification after blood reperfusion. In conclusion, we show here that CRMBM solution did not increase NO production during ischemia but induced an enhanced synthesis of NO during reperfusion which may be related to restoration of endothelial NOS expression and/or induction of inducible NOS expression.

[Chromosome synteny of the A genome of two evolutionary wheat lines]

In order to estimate synteny between A(t) and A polyploid wheat genomes belonging to different evolutionary lines (Timopheevi and Emmer), saturation of chromosome maps of Triticum timopheevii A(t) genome by molecular markers has been conducted. Totally, 179 EST-SSR and 48 genomic SSR-markers have been used with the following integration of 13 and 7 markers correspondingly into chromosome maps of A(t) genome. EST-SSR showed higher transferability and lower polymorphism than genomic SSR markers. The chromosome maps designed were compared to maps of homoeologous chromosome group of the T. aestivum A genome. No disturbances of colinearity, i.e., of the order of markers within the chromosome segments on which they had been previously mapped, were observed. According to the quantity assessment of markers amplifying in homoeologous chromosomes, the maximum divergence was detected in two groups (4A(t)/4A and 3A(t)/3A) among the seven chromosomes examined in the A(t) and A genomes. Comparison of molecular genetic mapping results with the published results of studying meiosis of F1 hybrids and the frequency of chromosomes substitution in introgressive T. aestivum x T. timopheevii lines suggest that individual chromosomes of the At and A genomes evolve differently. Translocations were shown to introduce the major impact on the divergence of 4A(t)/4A and 6A(t)/6A chromosomes, while mutations of the primary DNA structure, on the divergence of homoeologous group 3 chromosomes. The level of reorganization of other chromosomes during the evolution in the A(t) and A genomes was significantly lower.

[Usefulness of systematic brain magnetic resonance imaging in children with neurofibromatosis type 1]

BACKGROUND AND AIM

The aim of this study was to evaluate the usefulness of systematic screening of asymptomatic neurofibromatosis type 1 (NF1) children with magnetic resonance imaging (MRI).

PATIENTS AND METHODS

We retrospectively reviewed the MRIs of children diagnosed with NF1 disease according to the National Institutes of Health criteria, who had been followed for at least 1 year by the department of pediatric neurology (Lyon, France). Brain MRI was systematically performed in asymptomatic patients under 6 years of age.

RESULTS

One hundred patients with a median follow-up of 3.7 years (range, 1-8.6 years) were reviewed. Brain MRI was performed in a total of 94 children. Nine optic pathway gliomas were detected in symptomatic patients. Six children had symptoms caused by the tumor. Gliomas remained stable in 10 patients; 1 symptomatic glioma in an 8-year-old girl required treatment. Spontaneous regression was seen in 1 patient.

CONCLUSION

Our results suggest that MRI screening of asymptomatic children to detect optic pathway gliomas does not improve the therapeutic decision and should not be performed systematically. We suggest further investigation in collaboration with the French NF Network.

Can loud noise cause acoustic neuroma? Analysis of the INTERPHONE study in France

OBJECTIVES

To investigate possible associations between risk of acoustic neuroma and exposure to loud noise in leisure and occupational settings.

METHODS

A case-control study was conducted in France within the international INTERPHONE study. The cases were the 108 subjects diagnosed with acoustic neuroma between 1 June 2000 and 31 August 2003. Two controls per case were selected from the electoral rolls and individually matched for gender, age (5 years) and area (local authority district) of residence at the time of the case diagnosis. Multivariate analyses were conducted using conditional logistic regression. Adjustment was made for socioeconomic status.

RESULTS

Acoustic neuroma was found to be associated with loud noise exposure (odds ratio (OR) = 2.55; 95% CI 1.35 to 4.82), both in leisure settings, particularly when listening to loud music (OR = 3.88; 95% CI 1.48 to 10.17) and at work (OR = 2.26; 95% CI 1.08 to 4.72). This risk increased with exposure duration (>6 years' leisure exposure: OR = 3.15; 95% CI 1.07 to 9.24). Risk varied according to the type of noise (continuous or explosive vs intermittent).

CONCLUSION

The present results agree with other recent reports implicating loud noise in the risk of acoustic neuroma.

The impact of crown-rump length measurement error on combined Down syndrome screening: a simulation study

OBJECTIVE

To evaluate the impact of a 5-mm error in the measurement of crown-rump length (CRL) in a woman undergoing ultrasound and biochemistry sequential combined screening for Down syndrome.

METHODS

Based on existing risk calculation algorithms, we simulated the case of a 35-year-old-woman undergoing combined screening based on nuchal translucency (NT) measurement and early second-trimester maternal serum markers (human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP) expressed as multiples of the median (MoM)). Two measurement errors were considered (+ or - 5 mm), for four different CRLs (50, 60, 70 and 80 mm), with five different NT measurements (1, 1.5, 2, 2.5 and 3 mm) in a patient undergoing biochemistry testing at 14 + 4, 15, 16, 17 or 18 weeks' gestation. Four different values for each maternal serum marker were tested (1, 1.5, 2 and 2.5 MoM for hCG, and 0.5, 0.8, 1 and 1.5 MoM for AFP), leading to a total of 3200 simulations of the impact of measurement error. In all cases the ratio between the risk as assessed with or without the measurement error was calculated (measurement error-related risk ratio (MERR)).

RESULTS

Over 3200 simulated cases, MERR ranged from 0.53 to 2.14. In 586 simulations (18.3%), it was < 0.66 or > 1.33. Based on a risk cut-off of 1/300, women would have been misclassified in 112 simulations (3.5%). This would go up to 33 (27.5%) out of the 120 simulations in women with 'borderline' risk, with 1.5 MoM for hCG and 0.5 MoM for AFP, and NT measurement of 1 or 2mm.

CONCLUSION

Down syndrome screening may be highly sensitive to measurement errors in CRL. Quality control of CRL measurement should be performed together with quality control of NT measurement in order to provide the highest standard of care.

[Cardiac biomarkers for diagnosis of myocardial infarction]

Diagnosis of postoperative myocardial infarction is often difficult, based on tools with a low sensitivity (clinical symptoms, EKG), or with a low specifity (old biomarkers, echocardiographic abnormalities) or inadequate for clinical practice (scintigraphy). Since 1995, clinicians may use more cardiospecific markers (troponin) allowing to modify strategy for postoperative myocardial infarction diagnosis. The aim of this review is to resume such an attitude.

Evaluation of the genetic variability of homoeologous group 3 SSRs in bread wheat

Thorough characterization of the genetic variability in bread wheat (Triticum aestivum L.) is important for a better improvement of this key crop and to increase cereal yield in the context of sustainable agriculture to face human needs in the next decades. To study the genetic variability of SSRs on wheat homoeologous group 3 chromosomes, we characterized 38 hexaploid and two tetraploid wheat lines using a set of 165 microsatellites that we cytogenetically assigned to the 17 deletion bins for chromosomes group 3. A comparative analysis of the genetic variability through the PIC value study, allele numbers and SSR lengths indicated that there were no statistically significant differences (p > 0.05) between the three chromosomes of this homoeologous group despite the fact that SSRs from chromosome 3B exhibited slightly more alleles per locus compared to chromosomes 3A and 3D as well as slightly higher PIC values compared to chromosome 3D. However, there was a stronger correlation between SSR length and allele number on the short arms compared to the long arms and the correlation increased from the centromeres toward the telomeres. We did not find statistically significant differences in allele numbers and PIC values for SSRs located in more distal bins on 3A and 3B chromosomes. On the contrary, for chromosome 3D, we observed significant differences (p < 0.05) between the PIC values determined for SSRs assigned to deletion bin 3DL3-0.81-1.00 bin that is located distal compare to the more proximal region (C-3DL3-0.81). These results suggest that recombination which is higher in the telomeric regions does not contribute to increase a lot the variability of the SSRs.

Analysis of introgression of Aegilops ventricosa Tausch. genetic material in a common wheat background using C-banding

Seven Triticum aestivum (cv. Moisson)-Aegilops ventricosa addition lines and four VPM-1 lines were studied by C-banding, and compared with the parental common wheat cultivars Marne-Desprez (hereafter Marne), Moisson, and A. ventricosa lines 10 and 11. All of the VPM-1 lines had similar C-banding patterns and carried the same major 5B:7B translocation as the parental Marne cultivar. According to the C-banding analysis, the VPM-1 lines carry a complete 7D(7D(v)) chromosome substitution and a translocation involving the 5D and 5D(v) chromosomes. However, the translocation of the 2N(v)/6N(v) chromosome of A. ventricosa to the short arm of the 2A chromosome of wheat that had been identified in an earlier study using molecular analysis (Bonhomme A, Gale MD, Koebner RMD, Nicolas P, Jahier J, Bernard M in Theor Appl Genet 90:1042-1048, 1995; Jahier J, Abelard P, Tanguy AM, Dedryver F, Rivoal R, Khatkar S, Bariana HS Plant Breed 120:125-128, 2001) was not detected in our study. However, the appearance of a small pAs1 site at the tip of the chromosome 2A short arm in VPM-1 could be indicative of a minor translocation of the A. ventricosa chromosome. The 5B:7B translocation was also found in all seven T. aestivum-A. ventricosa addition lines, although it was not present in the parental common wheat cultivar Moisson. These lines showed different introgression patterns; besides the addition of the five N(v)-genome chromosomes, they also possessed different D(D(v)) genome substitutions or translocations. A whole arm translocation between chromosome 1N(v) and 3D(v) was identified in lines v86 and v137, and also in the A. ventricosa line 10. This observation lends further support to the idea that A. ventricosa line 10, rather than line 11, was used to develop a set of wheat A. ventricosa addition lines.

Soluble human leucocyte antigen-G molecules in peripheral blood haematopoietic stem cell transplantation: a specific role to prevent acute graft-versus-host disease and a link with regulatory T cells

Haematopoietic stem cell transplantation is often complicated by the life-threatening graft-versus-host disease (GVHD) which consists of an allogeneic reaction of the graft cells against the host organs. The aim of this study was to investigate the putative involvement of soluble human leucocyte antigen (sHLA) class I molecules, and particularly sHLA-G molecules, in the occurrence and/or prevention of acute GVHD (aGVHD) in allogeneic peripheral blood stem cell (PSC) transplantation. Whole sHLA class I molecules seem to be involved in aGVHD pathogenesis because detection of a high concentration of these molecules in the first month post allograft is correlated with aGVHD occurrence. Conversely, a high level of sHLA-G molecules before and after allograft could indicate good prognosis in PSC allograft transplantation. sHLA-G molecules seem to be involved in aGVHD prevention, not only because they are enriched in plasma of patients without aGVHD, but also because: (i) a positive correlation has been found between sHLA-G level and CD4+ CD25+ CD152+ natural regulatory T cell (T(reg)) frequency in the blood of transplanted patients; and (ii) the presence of CD4+ CD25+ CD152+ natural T(reg) is correlated with increased sHLA-G expression in in vitro mixed leucocyte reaction cultures. Altogether, these results support the immunomodulatory function of sHLA-G molecules that might create a regulatory network together with the natural T(reg) to foster the induction of a tolerogenic environment and improve PSC transplantation favourable outcome.

Chromosomal rearrangements in wheat: their types and distribution

Four hundred and sixty polyploid wheat accessions and 39 triticale forms from 37 countries of Europe, Asia, and USA were scored by C-banding for the presence of translocations. Chromosomal rearrangements were detected in 70 of 208 accessions of tetraploid wheat, 69 of 252 accessions of hexaploid wheat, and 3 of 39 triticale forms. Altogether, 58 types of major chromosomal rearrangements were identified in the studied material; they are discussed relative to 11 additional translocation types described by other authors. Six chromosome modifications of unknown origin were also observed. Among all chromosomal aberrations identified in wheat, single translocations were the most frequent type (39), followed by multiple rearrangements (9 types), pericentric inversions (9 types), and paracentric inversions (3 types). According to C-banding analyses, the breakpoints were located at or near the centromere in 60 rearranged chromosomes, while in 52 cases they were in interstitial chromosome regions. In the latter case, translocation breakpoints were often located at the border of C-bands and the euchromatin region or between two adjacent C-bands; some of these regions seem to be translocation "hotspots". Our results and data published by other authors indicate that the B-genome chromosomes are involved in translocations most frequently, followed by the A- and D-genome chromosomes; individual chromosomes also differ in the frequencies of translocations. Most translocations were detected in 1 or 2 accessions, and only 11 variants showed relatively high frequencies or were detected in wheat varieties of different origins or from different species. High frequencies of some translocations with a very restricted distribution could be due to a "bottleneck effect". Other types seem to occur independently and their broad distribution can result from selective advantages of rearranged genotypes in diverse environmental conditions. We found significant geographic variation in the spectra and frequencies of translocation in wheat: the highest proportions of rearranged genotypes were found in Central Asia, the Middle East, Northern Africa, and France. A low proportion of aberrant genotypes was characteristic of tetraploid wheat from Transcaucasia and hexaploid wheat from Middle Asia and Eastern Europe.