Diverged subpopulations in tropical Urochloa (Brachiaria) forage species indicate a role for facultative apomixis and varying ploidy in their population structure and evolution.

BACKGROUND: Urochloa (syn. Brachiaria) is a genus of tropical grasses sown as forage feedstock, particularly in marginal soils. Here we aimed to clarify the genetic diversity and population structure in Urochloa species to understand better how population evolution relates to ploidy level and occurrence of apomictic reproduction. METHODS: We explored the genetic diversity of 111 accessions from the five Urochloa species used to develop commercial cultivars. These accessions were conserved from wild materials collected at their centre of origin in Africa, and they tentatively represent the complete Urochloa gene pool used in breeding programmes. We used RNA-sequencing to generate 1.1 million single nucleotide polymorphism loci. We employed genetic admixture, principal component and phylogenetic analyses to define subpopulations. RESULTS: We observed three highly differentiated subpopulations in U. brizantha, which were unrelated to ploidy: one intermixed with U. decumbens, and two diverged from the former and the other species in the complex. We also observed two subpopulations in U. humidicola, unrelated to ploidy; one subpopulation had fewer accessions but included the only characterized sexual accession in the species. Our results also supported a division of U. decumbens between diploids and polyploids, and no subpopulations within U. ruziziensis and U. maxima. CONCLUSIONS: Polyploid U. decumbens are more closely related to polyploid U. brizantha than to diploid U. decumbens, which supports the divergence of both polyploid groups from a common tetraploid ancestor and provides evidence for the hybridization barrier of ploidy. The three differentiated subpopulations of apomictic polyploid U. brizantha accessions constitute diverged ecotypes, which can probably be utilized in hybrid breeding. Subpopulations were not observed in non-apomictic U. ruziziensis. Sexual Urochloa polyploids were not found (U. brizantha, U. decumbens) or were limited to small subpopulations (U. humidicola). The subpopulation structure observed in the Urochloa sexual-apomictic multiploidy complexes supports geographical parthenogenesis, where the polyploid genotypes exploit the evolutionary advantage of apomixis, i.e. uniparental reproduction and clonality, to occupy extensive geographical areas.

Integrating a newly developed BAC-based physical mapping resource for Lolium perenne with a genome-wide association study across a L. perenne European ecotype collection identifies genomic contexts associated with agriculturally important traits.

BACKGROUND AND AIMS: Lolium perenne (perennial ryegrass) is the most widely cultivated forage and amenity grass species in temperate areas worldwide and there is a need to understand the genetic architectures of key agricultural traits and crop characteristics that deliver wider environmental services. Our aim was to identify genomic regions associated with agriculturally important traits by integrating a bacterial artificial chromosome (BAC)-based physical map with a genome-wide association study (GWAS). METHODS: BAC-based physical maps for L. perenne were constructed from ~212 000 high-information-content fingerprints using Fingerprint Contig and Linear Topology Contig software. BAC clones were associated with both BAC-end sequences and a partial minimum tiling path sequence. A panel of 716 L. perenne diploid genotypes from 90 European accessions was assessed in the field over 2 years, and genotyped using a Lolium Infinium SNP array. The GWAS was carried out using a linear mixed model implemented in TASSEL, and extended genomic regions associated with significant markers were identified through integration with the physical map. KEY RESULTS: Between ~3600 and 7500 physical map contigs were derived, depending on the software and probability thresholds used, and integrated with ~35 k sequenced BAC clones to develop a resource predicted to span the majority of the L. perenne genome. From the GWAS, eight different loci were significantly associated with heading date, plant width, plant biomass and water-soluble carbohydrate accumulation, seven of which could be associated with physical map contigs. This allowed the identification of a number of candidate genes. CONCLUSIONS: Combining the physical mapping resource with the GWAS has allowed us to extend the search for candidate genes across larger regions of the L. perenne genome and identified a number of interesting gene model annotations. These physical maps will aid in validating future sequence-based assemblies of the L. perenne genome.

Transcriptome sequencing of Festulolium accessions under salt stress.

OBJECTIVES: The objective of this study was to establish transcriptome assemblies of Festulolium hybrids under salt stress, and identify genes regulated across the hybrids in response to salt stress. The development of transcriptome assemblies for Festulolium hybrids and cataloguing of genes regulated under salt stress will facilitate further downstream studies. RESULTS: Plants were grown at three salt concentrations (0.5%, 1% and 1.5%) and phenotypic and transcriptomic data was collected. Salt stress was confirmed by progressive loss of green leaves as salt concentration increased from 0 to 1.5%. We generated de-novo transcriptome assemblies for two Festulolium pabulare festucoid genotypes, for a single Festulolium braunii genotype, and a single F. pabulare loloid genotype. We also identified 1555 transcripts that were up regulated and 1264 transcripts that were down regulated in response to salt stress in the Festulolium hybrids. Some of the identified transcripts showed significant sequence similarity with genes known to be regulated during salt and other abiotic stresses.

Lymphocyte populations in tuberculous pleural effusions.

Different systemic and local responses to mycobacterial antigens suggest an active compartmentalization of responsive lymphocytes to tubercular antigens. This fact, observed in pleuritic processes, raises doubts about the accuracy of information obtained in the study of cells taken solely from peripheral blood. For this reason we decided to study the concept of compartmentalization in 140 patients suffering from pleural effusions. Patients were classified into six groups according to the aetiology of the effusion: group I, tuberculous, n = 23; group II, paraneoplastic, n = 41; group III, metapneumonic empyematous, n = 5; group IV, transudate, n = 38; group V, miscellaneous exudate, n = 19; group VI, unknown aetiology, n = 14. In each group we studied the lymphocyte population by using flow cytometry with doubly fluorescent monoclonal antibodies: B [expressing human lymphocyte antigen (HLA)-DR on the surface], T (CD3+), CD4+ and CD8+, and the subpopulation of activated T lymphocytes (together expressing CD3 and HLA-DR on the surface) (CD3+DR+). The study of these subpopulations in peripheral blood did not yield valuable results, but the CD3+DR+ population in pleural fluid demonstrated a diagnostic efficiency of 84% [positive predictive value (PPV) 51%, negative predictive value (NPV) 96%] at a cut-off value of 80.4 cells/mm3. The CD3+DR+ pleural fluid/peripheral blood ratio demonstrated an efficiency of 83% (PPV 50%, NPV 96%), and showed a statistically significant difference (P < 0.02) with regard to all the diagnostic groups, with the exception of the paraneoplastic effusions. The lymphocytic subpopulations study confirms the concept of compartmentalization in tuberculous pleuritis, as shown by the greater number of activated T lymphocytes present in pleural fluid in comparison with peripheral blood in tuberculous pleuritis, a 98% efficiency of adenosine deaminase (ADA) determination in pleural fluid versus a 50% value in peripheral blood, predominance of helper cells (CD4+) in pleural fluid and suppressor cells (CD8+) in peripheral blood, a greater CD4+/CD8+ ratio in pleural fluid than in peripheral blood, and a significant correlation of ADA-CD3+DR+ in pleural fluid, which does not occur in peripheral blood.

[Independent predictive factors of acute and first year success after electrical cardioversion in patients with chronic atrial fibrillation]. / Factores predictores independientes del éxito agudo y al año de la cardioversión eléctrica en pacientes con fibrilación auricular crónica.

OBJECTIVES: We retrospectively analyzed the predictive factors of successfully electrical cardioversion in patients with chronic atrial fibrillation. METHODS: We included 118 patients, 68 men and 50 women, with a mean age of 65.1 years and a length of arrhythmia evolution of 83.3 days. These patients consecutively underwent electrical cardioversion in our Cardiology Department with a follow-up of one year to determine relapses. Structural cardiopathy was observed in 63.6% of the patients and 43.7% presented a left atrium between 4 and 5 cms. We analyzed the clinical and echocardiographic factors which predict the acute and first year success of electrical cardioversion. RESULTS: The cardioversion was effective in 73.7% (CI 95%, 64.6%-81.1%) of the patients and 35.6% (CI 95%, 25.8%-46.6%) had a relapse within the first year. The inexistence of cardiomyopathy and therapy with amiodarone were predictive of acute success (p < 0.04 and p < 0.03, respectively). The length of arrhythmia evolution did not predict acute success but did so when relapses were analyzed. The size of the left atrium is predictive of both acute and long term success (p < 0.02 and p < 0.001, respectively). Logistic regression showed that the size of the left atrium and the patient's age were the only predictive factors of acute and first year success. CONCLUSIONS: Electrical cardioversion is very efficient in the short-term, despite numerous relapses. Patient age and the size of left atrium are associated with acute and long-term success of cardioversion.

[Results of a smoking cessation program among Spanish pulmonologists and thoracic surgeons]. / Resultado de un programa de cesación de tabaquismo en neumólogos y cirujanos torácicos españoles.

We evaluated the efficacy of a smoking cessation program using 16-hours nicotine patches offered by mail to physicians belonging to the Spanish Pneumological and Thoracic Surgery Society. Fifty-five subjects (21 women) with a mean age of 40 underwent treatment with 16-hours nicotine patches with different dose-time applications dependent on Fagerstrom test scores. Abstinence, which was verified by measuring carbon monoxide in expired air, was 23.6% after 6 months of follow-up. We observed a low rate of mild side effects.

[Cooperative study of bacterial incidence and susceptibility to cefamandole and other antibiotics (author's transl)]. / Ensayo multicéntrico de frecuencia bacteriana y sensibilidad a cefamandol y otros antibióticos.

A total of 44 medical centers participated in a cooperative study on nosocomial infections. Percentages of Gram-negative, Gram-positive and anaerobic germs isolated during 30 alternate-days for 3 months were 80.35 percent, 17.25 percent and 0.52 percent, respectively. Activity of cefamandole and cefalotin against Gram-positive bacteria was very similar, and both antibiotics showed a low number of resistances. On the contrary, against Gram-negative strains the activity of cefamandole was definitely superior to that of cefalothin, but it was similar when compared to that of gentamicin. In many instances, cefamandole may be a valid alternative in treating hospital-acquired infections (except for Pseudomonas).

[The use of Wagner's external fixator in the treatment of septic fractures of the femoral shaft (author's transl)]. / Le fixateur de Wagner dans le traitement des fractures septiques du fémur.

The authors have treated 10 cases of septic fracture of the femoral shaft by the following technique. In the first stage, necrotic and infected tissues were excised at the fracture site including soft tissue and bone. The importance of a large excision is emphasised. The fracture was then immobilised by an external fixator. In the second stage, the shaft was reconstructed by grafting using bone chips and sometimes massive cancellous bone autografts. The fixators were left until solid bone union had been achieved. 9 excellent results were observed. In one case, the bone refractured with recurrence of sepsis.

[Utility of bronchoalveolar lavage in the diagnosis of respiratory infection in HIV patients]. / Utilidad del lavado broncoalveolar en el diagnóstico de la infección respiratoria en pacientes HIV.

From January 1, 1992, to December 31, 1995, we studied 52 bronchoalveolar lavages in 45 HIV-infected patients. All patients with pulmonary symptoms and/or new pulmonary infiltrates underwent bronchoalveolar lavage (BAL) when the results of blood cultures and mycobacterial smears of sputum and urine were negative. Lavage fluid was investigated for the presence of P. carinii, bacteria, mycobacteria, fungi and virus. BAL was diagnostic in 39 (75%) cases. The organisms more frequently isolated were P. carinii and M. tuberculosis. Only one pathogen was identified in 28 cases (54%); two in ten (19%); and three in one patient (2%). BAL was, generally, well tolerated by the patient and had a high diagnostic yield in the evaluation of patients with HIV infection and respiratory symptoms.

Treatment results for ethmoid sinus carcinoma.

OBJECTIVE: The aim of this study was to describe the results of treatment in patients with ethmoid sinus carcinoma. MATERIALS AND METHOD: We performed a retrospective study of 34 patients with carcinoma of the ethmoid sinus, and collected the following data: age, sex, employment, tobacco and alcohol consumption, tumour-node-metastasis stage, treatment, and survival. RESULTS: The mean patient age was 64 years. Seventy-six per cent of patients were men and 24 per cent women. Squamous cell carcinoma was the most frequent histological tumour type (44 per cent). Eleven patients were classified as T(2), six as T(3), six as T(4a) and 11 as T(4b). Two patients (6 per cent) had nodal metastasis at the time of diagnosis. The anterior skull base was involved in 17 patients (50 per cent) and the anterior orbital contents were affected in seven patients (21 per cent). The five-year actuarial observed survival rate for all patients was 44 per cent. CONCLUSIONS: Combined treatment with surgery and post-operative radiotherapy permitted good local control in patients with ethmoid sinus carcinoma. We do not recommend prophylactic neck treatment for ethmoid sinus carcinoma.

Plasma redox status relates to severity in critically ill patients.

OBJECTIVE: To determine the relation between plasma redox status and severity of illness for patients admitted to an intensive care unit (ICU). DESIGN: A prospective cohort study. SETTING: A mixed medical and surgical adult ICU with 12 beds. PATIENTS: A total of 73 consecutive patients admitted to the ICU. INTERVENTIONS: Venous blood samples were routinely obtained within 24 hrs of admission. MEASUREMENTS AND MAIN RESULTS: Plasma total antioxidant capacity and lipoperoxides were measured by spectrophotometric technique at admission to the ICU. The plasma ratio total antioxidant capacity (mM)/lipoperoxides (microM) was used as an index of plasma redox status. Plasma concentration of the markers of leukocyte activation myeloperoxidase (enzyme-linked immunosorbent assay) and polymorphonuclear-elastase (immunoactivation assay) were also measured at admission to the ICU. Analysis of correlation between plasma ratio total antioxidant capacity/lipoperoxides and APACHE III score showed a negative association (p < .001, Spearman correlation test). Myeloperoxidase and polymorphonuclear-elastase correlated positively with Acute Physiology and Chronic Health Evaluation III scores (r2 = 0.58; p < .001; and r2 = 0.05; p = .035; respectively). CONCLUSIONS: Plasma redox status relates to severity in critically ill patients. We propose that it would be reasonable to provide antioxidant therapy as part of routine management of patients admitted to a mixed ICU, regardless of the specific reason for ICU admission. Plasma redox status might become useful to evaluate the risk in critically ill patients.