Genetics of alternative splicing evolution during sunflower domestication.

Alternative splicing enables organisms to produce the diversity of proteins necessary for multicellular life by using relatively few protein-coding genes. Although differences in splicing have been identified among divergent taxa, the shorter-term evolution of splicing is understudied. The origins of novel splice forms, and the contributions of alternative splicing to major evolutionary transitions, are largely unknown. This study used transcriptomes of wild and domesticated sunflowers to examine splice differentiation and regulation during domestication. We identified substantial splicing divergence between wild and domesticated sunflowers, mainly in the form of intron retention. Transcripts with divergent splicing were enriched for seed-development functions, suggesting that artificial selection impacted splicing patterns. Mapping of quantitative trait loci (QTLs) associated with 144 differential splicing cases revealed primarily trans-acting variation affecting splicing patterns. A large proportion of identified QTLs contain known spliceosome proteins and are associated with splicing variation in multiple genes. Examining a broader set of wild and domesticated sunflower genotypes revealed that most differential splicing patterns in domesticated sunflowers likely arose from standing variation in wild Helianthus annuus and gained frequency during the domestication process. However, several domesticate-associated splicing patterns appear to be introgressed from other Helianthus species. These results suggest that sunflower domestication involved selection on pleiotropic regulatory alleles. More generally, our findings indicate that substantial differences in isoform abundances arose rapidly during a recent evolutionary transition and appear to contribute to adaptation and population divergence.

Are Oxidative Stress Biomarkers Sensitive to Environmental Concentrations of Chlorpyrifos Exposed to the Freshwater Crab, Zilchiopsis collastinensis (Decapoda; Trichodactylidae)?

Global trends in pesticide use can increase aquatic pollution and affect resident fisheries. Crabs exposed to organophosphate pesticides, such as chlorpyrifos, may increase production of reactive oxygen species (ROS), affecting the pro-oxidant/antioxidant balance. Zichiopsis collastinensis crabs were exposed to environmentally relevant concentrations of chlorpyrifos (0.1 and 0.5 µg L-1). Effects on the oxidative stress enzymes catalase, superoxide dismutase, glutathione S-transferases, glutathione reductase, and on thiobarbituric acid reactive substances and hydrogen peroxide concentrations were evaluated at four intervals during 96 h exposures. Exposures caused decreased GST activity and increased H2O2 levels in gills. There were modifications of GST, CAT and SOD activities in the hepatopancreas after 12 h of exposure, and an increase of H2O2 levels at every exposure interval observed. The present study proved that chlorpyrifos lead to oxidative stress in Z. collastinensis. However other enzymatic/non-enzymatic responses should be further investigated in order to be included as part of a battery of biomarkers, together with H2O2 levels, which is a parameter highly recommended to be taken into account.

Carbapenemase-Producing Extraintestinal Pathogenic Escherichia coli From Argentina: Clonal Diversity and Predominance of Hyperepidemic Clones CC10 and CC131.

Extraintestinal pathogenic Escherichia coli (ExPEC) causes infections outside the intestine. Particular ExPEC clones, such as clonal complex (CC)/sequence type (ST)131, have been known to sequentially accumulate antimicrobial resistance that starts with chromosomal mutations against fluoroquinolones, followed with the acquisition of bla CTX-M-15 and, more recently, carbapenemases. Here we aimed to investigate the distribution of global epidemic clones of carbapenemase-producing ExPEC from Argentina in representative clinical isolates recovered between July 2008 and March 2017. Carbapenemase-producing ExPEC (n = 160) were referred to the Argentinean reference laboratory. Of these, 71 were selected for genome sequencing. Phenotypic and microbiological studies confirmed the presence of carbapenemases confirmed as KPC-2 (n = 52), NDM-1 (n = 16), IMP-8 (n = 2), and VIM-1 (n = 1) producers. The isolates had been recovered mainly from urine, blood, and abdominal fluids among others, and some were from screening samples. After analyzing the virulence gene content, 76% of the isolates were considered ExPEC, although non-ExPEC isolates were also obtained from extraintestinal sites. Pan-genome phylogeny and clonal analysis showed great clonal diversity, although the first phylogroup in abundance was phylogroup A, harboring CC10 isolates, followed by phylogroup B2 with CC/ST131, mostly H30Rx, the subclone co-producing CTX-M-15. Phylogroups D, B1, C, F, and E were also detected with fewer strains. CC10 and CC/ST131 were found throughout the country. In addition, CC10 nucleated most metalloenzymes, such as NDM-1. Other relevant international clones were identified, such as CC/ST38, CC155, CC14/ST1193, and CC23. Two isolates co-produced KPC-2 and OXA-163 or OXA-439, a point mutation variant of OXA-163, and three isolates co-produced MCR-1 among other resistance genes. To conclude, in this work, we described the molecular epidemiology of carbapenemase-producing ExPEC in Argentina. Further studies are necessary to determine the plasmid families disseminating carbapenemases in ExPEC in this region.

[Chronic pulmonary insufficiency after tetralogy of Fallot and pulmonary stenosis intervention. Pulmonary valve replacement with mechanical prosthesis]. / Insuficiencia pulmonar crónica secundaria a tetralogía de Fallot y estenosis pulmonar intervenida. Recambio valvular pulmonar con prótesis metálica.

INTRODUCTION: Tetralogy of Fallot and pulmonary stenosis are a frequent cause of consultation in patients with congenital heart disease. Interventions performed in infancy can cause residual pulmonary insufficiency and may require pulmonary valve replacement when adults. METHODS: From 2003 to 2007, 37 patients underwent right ventricular outflow tract or pulmonary valve intervention (tetralogy of Fallot and pulmonary stenosis). Differences between echocardiographic parameters in both pathologies, indications for pulmonary valvular replacement and the type of prosthesis used, were studied. RESULTS: 25 (67.6 %) patients had tetralogy of Fallot and 12 (32.4 %) pulmonary stenosis. In the pulmonary stenosis group, 7 patients had pulmonary valvulotomy in infancy and 5 had percutaneous pulmonary valvuloplasty in adulthood. Fallot patients received a transannular patch. No significant differences were seen in echocardiographic parameters (right and left ventricular diameter, pulmonary insufficiency, transpulmonary gradient and left ventricular ejection fraction). Mechanical prosthesis valve replacement was performed in 5 (13.5 %) patients, with no morbidity-mortality and with a significant improvement of the functional class. CONCLUSIONS: Chronic pulmonary insufficiency is a frequent complication after intervention of tetralogy of Fallot and pulmonary stenosis. Mechanical prosthesis valve replacement has low morbidity-mortality and low risk of complications after short to medium-term follow-up.

Analysis by partitioning in aqueous two-phase systems of the loss of transferrin-binding capacity during maturation of rat reticulocytes.

A decrease in the number of binding sites for 125I-transferrin, without an apparent modification of the association constant, has been observed during the maturation of reticulocytes into erythrocytes. As an experimental model, different red cell populations from phenylhydrazinic anaemic rates (95% to 12% reticulocyte-rich) have been used. The fractionation by multiple partition in two-phase systems of these red cell populations has been applied here to show the relationship between number of transferrin receptors and rate of reticulocyte maturation.

Rat bone marrow erythroid cell fractionation by counter current distribution in non-charge-sensitive two-phase systems.

Counter-current distribution in non charge-sensitive aqueous poly(ethylene glycol)-dextran two phase systems allows the fractionation of rat bone marrow cells into two broad cell subpopulations with different distribution coefficients in a relatively short time. Morphological identification and enzymatic studies suggest that erythroid cells are mainly present in the subpopulation with the higher distribution coefficient. The distribution coefficient and, therefore, surface hydrophobicity of these cells, apparently increase in parallel with an increase in their degree of differentiation and maturation.

Transferrin binding capacity as a marker of differentiation and maturation of rat erythroid cells fractionated by counter current distribution in aqueous polymer two-phase systems.

Rat bone marrow cell populations, containing different proportions of erythroid cells, have been fractionated by counter-current distribution in the non-charge-sensitive dextran/polyethyleneglycol two-phase systems on the basis of hydrophobic cell surface properties. Cell fractions with a low distribution coefficient, which contain non-erythroid cells and early erythoblasts, showed a low transferrin binding capacity and a low haemoglobin/cell ratio whereas cell fractions with a high distribution coefficient, which contain intermediate-late erythroblasts and mature red cells, showed an elevated transferrin binding capacity and the highest haemoglobin/cell ratio. These results support transferrin binding capacity as a good marker parameter for the erythroid bone marrow cell differentiation and maturation processes.

Towards new thymidine phosphorylase/PD-ECGF inhibitors based on the transition state of the enzyme reaction.

Computational studies have been conducted to built a closed form of TPase and to characterize the transition state of the phosphorylisis reaction catalyzed by TPase. The results obtained point to a crucial role of His-85 and the O2 of thymine in the catalysis. This modelled transition state forms the basis for the design of new TPase inhibitors.

[A superior vena cava syndrome due to a surgical retractor]. / Síndrome de vena cava superior por retractor quirúrgico.

A 56-year-old male diagnosed of epidermoid carcinoma of the right lung (T4 N0 M0, stage IIIb) is described. He had earlier received chemotherapy and radiotherapy and was scheduled for removal of the right lung. During surgery the need to resect tumor infiltration of the right atrium became evident. During weaning from by-pass sudden deterioration of hemodynamics occurred with poor response to volume and inotropic drugs. Superior vena cava syndrome due to traction of the innominate trunk from a surgical retractor was diagnosed; the crisis resolved when the retractor was withdrawn. We discuss the pathophysiology of this clinical picture and relevant intraoperative aspects.

Care of the pregnant asthmatic.

Treatment of asthma in the pregnant female poses a dilemma for the physician who must select medications that will effectively suppress maternal bronchospasm but that will not jeopardize the fetus. To compound the practitioner's problem, the inability to perform human studies with asthma drugs has led the pharmaceutical companies to formally list precautions against the use of antiasthmatic drugs during pregnancy in the Physician's Desk Reference (PDR), a book which is available to the lay public and is often introduced in medicolegal suits as the primary reference for standard of care. This article provides the clinician with the current recommended treatments that are considered acceptable during pregnancy based on the published evidence involving animal studies and the cumulative human experience that is reported in the English language medical literature.

Respiratory failure associated with the post-polio syndrome.

The recent medical literature documents the occurrence of progressive muscle weakness 30 to 40 years after apparent recovery from poliomyelitis. We present a patient whose respiratory failure was attributed to the late effects of poliomyelitis on the respiratory muscles via spinal cord impairment. We examine the characteristics and proposed causes of the "postpolio syndrome."

Perceptions and utilization of hyperbaric oxygen therapy for carbon monoxide poisoning in an academic setting.

The routine use of hyperbaric oxygen as therapy for carbon monoxide intoxication is being critically reexamined nationally. There are no controlled prospective clinical studies that show this modality to clearly be superior to the more traditional use of high concentrations of supplemental oxygen. Proponents of hyperbaric therapy often claim that such studies would now be unethical, would violate the accepted standard of care for this medical emergency, and would place the treating physician in an indefensible medical-legal position. In an attempt to determine the status of hyperbaric oxygen in our community as treatment for significant carbon monoxide exposure, we surveyed physicians practicing at the university regional trauma center to determine their perception of the indications for hyperbaric oxygen therapy for carbon monoxide poisoning. We then audited the medical records of all patients treated during a four-year period with the diagnosis of carbon monoxide poisoning or smoke inhalation to determine the actual utilization of this therapeutic modality. The results of our study indicate that hyperbaric referral is not the standard treatment for significant carbon monoxide intoxication in this academic setting.

[Bilateral compartment syndrome after surgical perfusion for chronic ischemia of the lower extremities]. / Síndrome compartimental bilateral tras reperfusión quirúrgica en la isquemia crónica de miembros inferiores.

A 61-year-old man diagnosed with advanced stage Leriche syndrome underwent revascularization surgery with placement of an aortobifemoral shunt and prosthesis under combined general and lumbar epidural anesthesia. After 6 hours he developed bilateral lower extremity compartment syndrome with acute anuric kidney failure caused by severe rhabdomyolysis. Thirty hours after surgery the patient suffered cardiac arrest due to hyperkalemia and was unresponsive to advanced cardiopulmonary resuscitation. The delay in diagnosis, in part owing to the epidural block provided for surgery, and loss of muscle mass led to the unfavorable outcome in this case.

[Common variable immunodeficiency associated with autoimmune thrombocytopenia: anesthetic management]. / Inmunodeficiencia variable común asociada a trombopenia autoinmune: manejo anestésico.

A 44-year-old man diagnosed of common variable immunodeficiency associated with thrombopenia due to autoimmunity required anesthesia for anal fissure repair and hemorrhoidectomy. Hemostatic complications developed after surgery, with extreme thrombopenia (1,000 platelets/pl) and analytical changes that necessitated administration of six units of platelets from apheresis, as well as immunoglobulins, antifibrinolytic agents (e-aminocaproic acid) and granulocytic colony stimulating factors. Anesthesia for such patients is reviewed, with emphasis on careful management of the airways, preparation of sufficient material for surgery (rapid transfusion equipment, large caliber intravenous catheters, sterile material) and orientation of anesthetic technique toward general anesthesia through a laryngeal mask.

[Clinical assessment of a new anesthetic system: the Temel Supra (II)]. / Análisis clínico de un nuevo sistema de anestesia: Temel Supra (II).

OBJECTIVES: To assess the clinical performance of a new anesthetic system developed to provide novel advantages in ventilating the anesthetized patient. PATIENTS AND METHOD: The clinical performance of the Temel Supra was evaluated in 100 adult patients who were anesthetized and ventilated using the device. RESULTS: The patients were adequately oxygenated and ventilated; no adverse events were observed. An open circuit, low flow, or closed circuit could be chosen freely. Ventilation was fully monitored: among the variables measured were rebreathed volume; leaks while the patient was connected; consumption of oxygen, nitrous oxide and anesthetic agents; and cardiac output (noninvasively). CONCLUSIONS: Ventilation and gas exchange were satisfactory in all cases even though some patients developed considerable respiratory impedance. The monitoring of oxygen and other gases consumed and of carbon dioxide produced provided very valuable information about metabolism and pharmacokinetics. The noninvasive monitoring of cardiac output seems to us to be a useful feature for aiding hemodynamic control. The independence of the open and closed circuits means that expired gases do not pass through the canister when the open circuit is used, resulting in savings on soda lime for drying. During pressure-control ventilation, the system maintains a plateau to guarantee better distribution of inspired gases. Other important features are warnings, constant monitoring of leaks, the 100% efficacy of the circuit, and the low internal volume.

Affinity-mediated modification of electrical charge on a cell surface: a new approach to the affinity partitioning of biological particles.

Polylysine has been covalently bound to human transferrin in a 1:1 molar ratio over a disulfide bond that can be easily split by reducing agents such as dithiothreitol. The association constant for the binding of the transferrin-polylysine derivative to transferrin receptors present on rat erythroblasts and the number of binding sites were identical to the corresponding values found for native transferrin. The incubation of the cells with transferrin-polylysine affected the partitioning of erythroblasts in a charge-sensitive aqueous two-phase system containing Dextran and polyethylene glycol. The polylysine part introduced a nonspecific influence on the partitioning that could be eliminated by preincubation of the cells with an excess of sialic acid. The partition ratio, G, of the erythroblasts changed with a factor of 1.9 for each set of 100,000 polylysine chains attached per cell.

Fractionation of erythroblasts with affinity-mediated modifications of their electrical properties using counter-current distribution.

We have previously reported the possibility of modifying the electrical properties of cells by means of their interaction with a specific ligand carrying a polyelectrolyte (Anal Biochem 200: 280-285). This selective modification of receptor-containing cells changed their partition in a charge-sensitive aqueous two-phase system. We here present the fractionation of electrically modified erythroblasts by the use of an automatic multiple-partition procedure, counter-current distribution. The cells were fractionated according to the degree of differentiation of erythroblasts as evaluated from the hemoglobin content as well as the relative activities of the two enzymes, 3-phosphoglycerate kinase and bisphospho-glycerate mutase.