Identification and Molecular Characterization of Leaf Rust Resistance Gene Lr14a in Durum Wheat

Leaf rust, caused by Puccinia triticina, is an important disease of durum wheat (Triticum turgidum subsp. durum) and only a few designated resistance genes are known to occur in this crop. A dominant leaf rust resistance gene in the Chilean durum cv. Llareta INIA was mapped to chromosome arm 7BL through bulked segregant analysis using the amplified fragment length polymorphism (AFLP) technique, and by mapping three polymorphic markers in the common wheat (T. aestivum) International Triticeae Mapping Initiative population. Several simple sequence repeat (SSR) markers, including Xgwm344-7B and Xgwm146-7B, were associated with the leaf rust resistance gene. Resistance response and chromosomal position indicated that this gene is likely to be Lr14a. The SSR markers Xgwm344-7B and Xgwm146-7B and one AFLP marker also differentiated common wheat cv. Thatcher from the near-isogenic line with Lr14a, as well as durum 'Altar C84' from durum wheat with Lr14a. This is the first report of the presence of Lr14a in durum wheat, although the gene originally was transferred from emmer wheat 'Yaroslav' to common wheat. Lr14a is also present in CIMMYT-derived durum 'Somateria' and effective against Mexican and other P. triticina races of durum origin. Lr14a should be deployed in combination with other effective leaf rust resistance genes to prolong its effectiveness in durum wheat.

Biaxial strain in the hexagonal plane of MnAs thin films: the key to stabilize ferromagnetism to higher temperature

The alpha-beta magnetostructural phase transition in MnAs/GaAs(111) epilayers is investigated by elastic neutron scattering. The in-plane parameter of MnAs remains almost constant with temperature from 100 to 420 K, following the thermal evolution of the GaAs substrate. This induces a temperature dependent biaxial strain that is responsible for an alpha-beta phase coexistence and, more importantly, for the stabilization of the ferromagnetic alpha phase at a higher temperature than in the bulk. We explain the premature appearance of the beta phase at 275 K and the persistence of the ferromagnetic alpha phase up to 350 K with thermodynamical arguments based on the MnAs phase diagram. It results that the biaxial strain in the hexagonal plane is the key parameter to extend the ferromagnetic phase well over room temperature.

Effect of the choice of food composition table on nutrient estimates: a comparison between the British and American (Chilean) tables

Objective:

To determine the level of agreement between the American (Chilean) and British food composition tables in estimating intakes of macronutrients and antioxidants.

Results:

Mean differences between the two tables of food composition ranged from 5.3% to 8.9% higher estimates when using the American (Chilean) table for macronutrients. For micronutrients, a bias towards a higher mean was observed for vitamin E, iron and magnesium when the American (Chilean) table was used, but the opposite was observed for vitamin A and selenium. The intra-class correlation coefficient (ICC) ranged from 0.86 (95% confidence interval (CI) 0.81–0.91) to 0.998 (95% CI 0.995–1.00), indicating high to excellent agreement. LOAs for macronutrients and vitamins A and C were satisfactory, as they were sufficiently narrow. There was more uncertainty for other micronutrients.

Conclusion:

The American table gives relative overestimates of macronutrients in comparison to the British table, but the relative biases for micronutrients are inconsistent. Estimates of agreement between the two food composition tables provide reassurance that results are interchangeable for the majority of nutrients.

Spectroscopic measurement of spin-dependent resonant tunneling through a 3D disorder: the case of MnAs/GaAs/MnAs junctions

We propose an analytical model of spin-dependent resonant tunneling through a 3D assembly of localized states (spread out in energy and in space) in a barrier. An inhomogeneous distribution of localized states leads to resonant tunneling magnetoresistance inversion and asymmetric bias dependence as evidenced with a set of experiments with MnAs/GaAs(7-10 nm)/MnAs tunnel junctions. One of the key parameters of our theory is a dimensionless critical exponent beta scaling the typical extension of the localized states over the characteristic length scale of the spatial distribution function. Furthermore, we demonstrate, through experiments with localized states introduced preferentially in the middle of the barrier, the influence of an homogeneous distribution on the spin-dependent transport properties.

Antigenemia for cytomegalovirus in renal transplantation: choosing a cutoff for the diagnosis criteria in cytomegalovirus disease

Cytomegalovirus (CMV) infection is a frequent complication in transplant recipients, causing a high level of morbidity and mortality. We studied 203 consecutive renal transplant recipients performed between January 2000 and December 2001. Patients underwent weekly measurements of CMV pp65 antigen to assess CMV activity from the 4th to the 12th week posttransplantation. The results were reported as number of cells positive for the pp65 antigen among 10(5) granulocytes. In order to define a best cutoff to diagnose CMV disease with desirable sensitivity and specificity, we used a receiver operator characteristics (ROC) curve. The cutoff of four positive cells corresponded to a sensitivity of 93% and specificity of 60% (AUC = 0.87) for the diagnosis of CMV disease. The chosen cutoff for starting antiviral treatment was 10 cells, since this was associated with a sensitivity of 92% and specificity of 70% (AUC = 0.90). In conclusion, the highly sensitive cutoff points for the diagnosis of antigenemia was four cells and 10 cells for initiation of antiviral therapy.

Dietary intake of flavonoids and asthma in adults

Epidemiological studies have suggested that a high consumption of apples may protect against asthma and chronic obstructive pulmonary disease. This effect has been attributed to their high flavonoid content, but few studies have investigated the relationship between flavonoid intake and obstructive lung disease directly. In a population-based, case-control study of 1,471 adults aged 16-50 yrs in London (UK), the present study examined whether dietary intake of catechins, flavonols and flavones was negatively associated with asthma, asthma severity and chronic sputum production. Asthma was defined by positive responses to a standard screening questionnaire in 1996 and information about usual diet was obtained by a food frequency questionnaire in 1997. After controlling for potential confounders, dietary intake of these three flavonoid subclasses was not significantly associated with asthma, (odds ratio per quintile (95% confidence interval) = 0.94 (0.86-1.02); 1.00 (0.92-1.09); 0.98 (0.88 -1.08) for flavones, flavonols and total catechins, respectively) nor was it associated with asthma severity, or chronic sputum production. In conclusion, no evidence was found for a protective effect of three major subclasses of dietary flavonoids on asthma. It is possible that other flavonoids or polyphenols present in apples may explain the protective effect of apples on obstructive lung disease.

Superconductivity of bulk CaC6

We have obtained bulk samples of the graphite intercalation compound, CaC6, by a novel method of synthesis from highly oriented pyrolytic graphite. The crystal structure has been completely determined showing that it is the only member of the MC6, metal-graphite compounds that has rhombohedral symmetry. We have clearly shown the occurrence of superconductivity in the bulk sample at 11.5 K, using magnetization measurements.

Clinical Relevance of Low Levels of Preformed Alloantibodies Detected by Flow Cytometry in the First Year Post–Kidney Transplantation

OBJECTIVE

To determine the prevalence of transplants performed with a false-negative cytotoxicity cross-match and to analyze the clinical relevance of alloantibodies (Ab) detected only by flow cytometry (flow).

METHODS

We studied 66 patients undergoing kidney transplantation from a cadaveric donor. All patients had a simultaneous negative T+AHG+DTT and B+DTT. Pretransplant sera were retrospectively analyzed by flow cytometry according to an Emory University protocol: (1) T+ and B-: Ab anti-class I; (2) T- and B+: anti-class II; (3) T+B+: anti-class I + II. Chi-square, Fisher exact, Student t test, and Kaplan Meier analyses were employed with significance assigned at P < or = .05.

RESULTS

The overall incidence of false-negative cytotoxicity was 33.3% (22/66), namely, 6.1% (n = 4) anti-class I; 9.1% (n = 6) anti-class II; and 18.2% (n = 12) anti-class I + II. Primary nonfunctioning grafts occurred in 6.8% (3/44) and 13.6% (3/22) negative and positive flow patients (two anti-class I + II and one class II; P = .39). The incidence of graft loss in the first year was respectively, 13.6% (6/44) and 18.2% (4/22; two anti-class II and two anti-class I + II; P = .72). Compared to flow-negative grafts, creatinine levels were significantly higher among flow-positive patients at 8 and 12 weeks. One-year graft survivals were 86.4% among negative versus 81.8% for the positive group (P = .67).

CONCLUSIONS

We observed that 33% of kidney transplant recipients had low levels of alloantibodies detected only by flow. This single factor was associated with the worst graft function in the first trimester with a suggestion of a higher risk for non-functioning graft.

Immunoglobulin G–Positive in B-Cell Cross-Match Decreases Kidney Allograft Survival

We retrospectively studied all 1149 transplants performed at our center between 1993 and 2003 to determine the incidence and clinical effect of pretransplant B-positive cross-match on kidney graft survival. The patients were divided in two groups: B-negative (n = 1102) and B-positive in current sera (n = 47; 4.1%). AB-positive test was more frequent among regrafted patients (14% vs 3%; P = .00). Demographic data were not different between the groups. The overall rate of graft loss was similar (26% vs 24%, respectively; P = .86). However, early nonsurgical graft losses were more frequent among B-positive patients (46% vs 20%, respectively; P = .04). IgM was the most frequent immunoglobulin in the B-positive group (76% IgM and 24% IgG). There was no significant difference between B-negative and B-positive groups in the 1-, 5-, and 10-year graft survival rates (87% vs 83%, 73% vs 78%, 64% vs 66%, respectively; P = .87). The graft survival was significantly reduced comparing an IgG anti-B cell to the B-negative group (P = .03) as well as IgG compared to IgM (P = .004). In conclusion, only B-positive cross-match due to IgG decreased graft survival. Even though it is an uncommon situation (0.9%), this study stressed the clinical value of the B-cell cross-match as a tool to identify patients with a higher immunological risk.

Cytomegalovirus disease latent and active infection rates during the first trimester after kidney transplantation

Cytomegalovirus (CMV) infection is the single most frequent infectious complication in renal transplant recipients. The aim of this study was to determine the incidence of latent and active infections with CMV during the first 3 months after kidney transplantation. From January 2000 to December 2001, 203 consecutive adult renal transplant recipients underwent weekly measurements of pp65 CMV antigen from the 4th to the 12th posttransplantation week. Latent infection (seropositivity) was found in 92% of the population. Primary infection occurred in 4.9% (10 of 203), among whom 66% were previously seronegative patients. Among the primary infection patients, 70% (7 of 10) developed severe disease. The overall incidence of viremia was 69.5%, being more frequent among cadaver recipients (79% vs 59%; P =.02). The overall incidence of CMV disease was 38.4% (78 of 203) with 24.6% classified as severe disease requiring antiviral therapy. In conclusion, our population showed a high prevalence of latent infection with viremia. Not all patients developed clinical disease. Most subjects experienced a mild spectrum of symptoms, probably due to the prospective search for active infection during the major risk period after kidney transplantation.

Syndrome néphrotique paranéoplasique et cancers broncho-pulmonaires

INTRODUCTION

Paraneoplastic nephrotic syndrome associated with malignant broncho-pulmonary tumors. Three cases and literature review. Malignant broncho-pulmonary tumours are the principal cause of a paraneoplastic nephrotic syndrome. These tumours are most often small cell or squamous bronchial carcinomas. In 75% of cases the nephrotic syndrome is due to a membranous glomerulonephritis and it usually precedes the discovery of the causative tumour.

CASES REPORT

Three cases of paraneoploastic nephrotic syndrome associated with bronchial carcinoma are described. The first is of a bronchial carcinoid tumour associated with a membrano-proliferative glomerulonephritis. In the second a bronchial adenocarcinoma was revealed by a membranous glomerulonephritis. The last case concerns a squamous carcinoma associated with a nephrotic syndrome in which the histological lesions were not documented on account of progression to rapidly fatal acute renal failure.

CONCLUSION

A revue of the literature describes the associations between paraneoplastic nephrotic syndrome and bronchial carcinoma.

IL-10 down-regulates costimulatory molecules on Mycobacterium tuberculosis-pulsed macrophages and impairs the lytic activity of CD4 and CD8 CTL in tuberculosis patients

Activation of T cells requires both TCR-specific ligation and costimulation through accessory molecules during T cell priming. IFNgamma is a key cytokine responsible for macrophage activation during Mycobacterium tuberculosis (Mtb) infection while IL-10 is associated with suppression of cell mediated immunity in intracellular infection. In this paper we evaluated the role of IFNgamma and IL-10 on the function of cytotoxic T cells (CTL) and on the modulation of costimulatory molecules in healthy controls and patients with active tuberculosis (TB). gamma-irradiated-Mtb (i-Mtb) induced IL-10 production from CD14(+) cells from TB patients. Moreover, CD3(+) T cells of patients with advanced disease also produced IL-10 after i-Mtb stimulation. In healthy donors, IL-10 decreased the lytic activity of CD4(+) and CD8(+) T cells whereas it increased gammadelta-mediated cytotoxicity. Furthermore, we found that the presence of IL-10 induced a loss of the alternative processing pathways of antigen presentation along with a down-regulation of the expression of costimulatory molecule expression on monocytes and macrophages from healthy individuals. Conversely, neutralization of endogenous IL-10 or addition of IFNgamma to either effector or target cells from TB patients induced a strong lytic activity mediated by CD8(+) CTL together with an up-regulation of CD54 and CD86 expression on target cells. Moreover, we observed that macrophages from TB patients could use alternative pathways for i-Mtb presentation. Taken together, our results demonstrate that the presence of IL-10 during Mtb infection might contribute to mycobacteria persistence inside host macrophages through a mechanism that involved inhibition of MHC-restricted cytotoxicity against infected macrophages.

Cross-species transferability and mapping of genomic and cDNA SSRs in pines

Two unigene datasets of Pinus taeda and Pinus pinaster were screened to detect di-, tri- and tetranucleotide repeated motifs using the SSRIT script. A total of 419 simple sequence repeats (SSRs) were identified, from which only 12.8% overlapped between the two sets. The position of the SSRs within their coding sequences were predicted using FrameD. Trinucleotides appeared to be the most abundant repeated motif (63 and 51% in P. taeda and P. pinaster, respectively) and tended to be found within translated regions (76% in both species), whereas dinucleotide repeats were preferentially found within the 5'- and 3'-untranslated regions (75 and 65%, respectively). Fifty-three primer pairs amplifying a single PCR fragment in the source species (mainly P. taeda), were tested for amplification in six other pine species. The amplification rate with other pine species was high and corresponded with the phylogenetic distance between species, varying from 64.6% in P. canariensis to 94.2% in P. radiata. Genomic SSRs were found to be less transferable; 58 of the 107 primer pairs (i.e. 54%) derived from P. radiata amplified a single fragment in P. pinaster. Nine cDNA-SSRs were located to their chromosomes in two P. pinaster linkage maps. The level of polymorphism of these cDNA-SSRs was compared to that of previously and newly developed genomic-SSRs. Overall, genomic SSRs tend to perform better in terms of heterozygosity and number of alleles. This study suggests that useful SSR markers can be developed from pine ESTs.

[Outbreak of meningitis in the province of Logone occidental (Chad): descriptive study using health ministry data from 1998 to 2001]

Outbreaks of meningitis are a public health problem in sub-Saharan Africa where more than thousand cases are declared every year In Chad, the last outbreak happened between 1998 and 2001. The objective of this study is to describe epidemiologic profile of meningitis in the province of Logone Occidental from 1998 to 2001.

METHODS

Study used epidemiologic data of surveillance's tools from years 1998 to 2001 in Chad.

RESULTS

Data of the study indicated a two-yearly cycle with outbreaks in 1998 and 2000 occurring in endemic background during 1999 and 2001. The first cases began in January with an incidence rate close to 30 for 100.000/week. The epidemic peak occurred on the 11th week (1999-2001), on the 12th week (1998-2000) during dry season. Outbreak continued 9 weeks and stopped on the 16th week (April-May). The lethality average was 12% and reached 30% at the beginning of the outbreak.

DISCUSSION

Despite vaccination campaigns during outbreaks, epidemiology did not change in Chad. Quality of epidemiological surveillance is not sufficient and political reaction is too slow. Moreover, human, material and financial deficiency add to these difficulties. Integrated vaccination against meningitis into the immunization preventive program was evocated but would not permit enough collective immunity. Biotope changes generated by human activity could contribute to perpetuating outbreaks. New outbreak of W135 meningitis in Burkina Faso (2002) may change the epidemiological profile of the meningitis in sub-Saharan Africa.

CONCLUSION

Meningitis outbreaks control using vaccination after the first cases appears to be limited, however this strategy must be evaluated in Chad to know vaccination covering, target population and protection after vaccination.

Comparison between RFLP-PCR and antigenemia for pp65 antigen for diagnosis of cytomegalovirus disease after kidney transplantation

Cytomegalovirus (CMV) infection is the single most frequent infectious complication in renal transplant recipients. The purpose of this study was to analyze the diagnostic efficacy of PCR-RFLP compared to antigenemia for CMV disease (CMVD) in kidney transplant recipients. From November 2001 to February 2002, 19 renal adult transplant recipients were followed with weekly measurements of CMV pp65 antigen to monitor the activity of CMV from the week 4 to 12 posttransplantation. Only 4 (21.1%) patients did not develop viremia during the first 12 posttransplantation weeks. Active infection was observed in 15 patients (78.9%): asymptomatic viremia in 6 (31.6%) and CMVD in 9 (47%). All patients who developed CMVD showed positivity in both methods during the observation period. The number of positive cells ranged from 11 to 292 cells in patients with CMVD and one to eight cells among those with asymptomatic viremia. Both methods revealed 100% sensitivity for CMVD diagnosis. The specificity was 60% for antigenemia and 70% for PCR, with positive predictive values of 60% and 75%, respectively.

Management of splenic artery aneurysms and false aneurysms with endovascular treatment in 12 patients

PURPOSE

To assess the endovascular treatment of splenic artery aneurysms and false aneurysms.

METHODS

Twelve patients (mean age 59 years, range 47-75 years) with splenic artery aneurysm (n = 10) or false aneurysm (n = 2) were treated. The lesion was asymptomatic in 11 patients; hemobilia was observed in one patient. The lesion was juxta-ostial in one case, located on the intermediate segment of the splenic artery in four, near the splenic hilus in six, and affected the whole length of the artery in one patient. In 10 cases, the maximum lesion diameter was greater than 2 cm; in one case 30% growth of an aneurysm 18 mm in diameter had occurred in 6 months; in the last case, two distal aneurysms were associated (17 and 18 mm in diameter). In one case, stent-grafting was attempted; one detachable balloon occlusion was performed; the 10 other patients were treated with coils.

RESULTS

Endovascular treatment was possible in 11 patients (92%) (one failure: stenting attempt). In four cases among 11, the initial treatment was not successful (residual perfusion of aneurysm); surgical treatment was carried out in one case, and a second embolization in two. Thus in nine cases (75%) endovascular treatment was successful: complete and persistent exclusion of the aneurysm but with spleen perfusion persisting at the end of follow-up on CT scans (mean 13 months). An early and transient elevation of pancreatic enzymes was observed in four cases.

CONCLUSION

Ultrasound and CT have made the diagnosis of splenic artery aneurysm or false aneurysm more frequent. Endovascular treatment, the morbidity of which is low, is effective and spares the spleen.