Sub-chronic effects of nitrate in drinking water on red-legged partridge (Alectoris rufa): oxidative stress and T-cell mediated immune function.

In order to evaluate the effects of nitrates on birds, we have exposed captive red-legged partridges to nitrates concentrations of 0 (control), 100 (dwell water in farming areas) or 500 mg/l (fertirrigation level). The cellular immune response, plasma biochemistry, methemoglobin concentration (metHb), and oxidative stress biomarkers in blood and tissues were studied after two weeks of exposure. Several blood parameters such as aspartate aminotransferase, creatinine phosphokinase and lactate dehydrogenase activities and magnesium level decreased with nitrate exposure, whereas alkaline phosphatase activity and creatinine level increased. The oxidant effect of nitrates was evidenced by the increase in blood metHb, accompanied by the lipid peroxidation of red blood cells, the increased levels of oxidized glutathione (GSH) in liver, and the generation of oxidative DNA damage in plasma lymphocytes. GSH in erythrocytes was negatively correlated with blood metHb. The cellular immune function was slightly lower at partridges exposed to nitrates. These results suggest that adverse effects of nitrates on birds occur at concentrations potentially present in the field.

[Morbi-mortality of medical and surgical treatments in the intracranial bleeding like complication of therapy with drugs that modifies normal coagulation]. / Morbimortalidad del tratamiento médico conservador y del tratamiento neuroquirúrgico en los casos de hemorragia intracraneal como complicación del empleo de fármacos que modifican la hemostasia.

INTRODUCTION: Antiaggregant and anticoagulant therapy has possible sever secondary effects, being the most serious intracranial bleeding. OBJECTIVES: Compare morbi-mortality between surgical and medical treatments in anticoagulated and/or antiaggregated patients with any kind of intracranial bleeding. Also risk factors and main indications of those treatments are studied. PATIENTS AND METHODS: Descriptive and retrospective study including 105 patients admitted in our Critical Care Unit, with intracranial bleeding, under anticoagulant or antiaggregant treatment. We study the type of bleeding (subarachnoid, epidural, subdural and intraparenchimal bleeding) and the relation between morbi-mortality and treatment applicated using relative risk like analytic tool. RESULTS: Major bleeding risk appears after the six first months from the beginning of the treatment. Thirty-four patients died with a relative risk of 1.55 in the surgical patients from the medical treatment patients. Relative risk between anticoagulated patients and antiaggregated ones was 1.16. Serious consequences happened on eight of the 49 patients under surgical treatment, and on 13 of the 52 patients under medical treatment. CONCLUSIONS: Surgical treatment has more morbi-mortality. Oral anticoagulation has only a little more relative risk than treatment with antiaggregants. Both groups had serious consequences.

Two active-site tyrosyl residues of protein TrwC act sequentially at the origin of transfer during plasmid R388 conjugation.

Protein TrwC is the relaxase-helicase responsible for the initiation and termination reactions of DNA processing during plasmid R388 conjugation. Site-directed mutagenesis was used to change to phenylalanine each of a set of four conserved tyrosyl residues in the sequence of the N-terminal relaxation domain of the protein. Simultaneous mutation of both Y18 and Y26 was required to abolish in vitro cleavage and strand-transfer reactions catalyzed by protein TrwC on oligonucleotides containing the nic site. Thus, both Y18 and Y26 could be involved independently in the formation of oligonucleotide-protein covalent complexes that constitute presumed intermediates of these reactions. This hypothesis was confirmed by the observation of Y18 and Y26-specific peptide-oligonucleotide adducts after protease digestion of TrwC and mutant derivatives. Finally mutation Y18F, but not mutation Y26F, abolished nic-cleavage of a supercoiled DNA containing the R388 origin of transfer (oriT). These data allowed the construction of a model for conjugative DNA processing in which Y18 specifically catalyzes the initial cleavage reaction, while Y26 is used for the second strand-transfer reaction, which terminates conjugation. The model suggests a control mechanism that can be effective at each conjugative replication cycle.

Functional domains in protein TrwC of plasmid R388: dissected DNA strand transferase and DNA helicase activities reconstitute protein function.

TrwC is a bifunctional enzyme that displays two biochemical activities essential for plasmid R388 conjugation: oriT-specific DNA strand-transferase and DNA helicase activities. We overproduced and purified different segments of the protein allowing us to map the relaxase and DNA helicase activities to separate regions of the protein. A peptide comprising the N-terminal 275 amino acid residues of the protein was able to catalyze DNA cleavage and strand-transfer reactions when using oligonucleotides encompassing the nic site, although a longer fragment of TrwC (348 amino acid residues) was required to produce the nick on a supercoiled double-stranded DNA substrate. The segment of the protein between amino acid residues 192 and 966 contained the ATPase and DNA helicase activities, while a peptide consisting of amino acid residues 346 to 966 lost both activities. The dimerization region lay in the 495 C-terminal amino acid residues. Two peptides containing the DNA strand-transferase and DNA helicase activities, respectively, could functionally substitute for TrwC in R388 conjugation although at a 10,000-fold lower efficiency. Thus, integrity of the covalent structure of the protein was required for efficient DNA transfer. It can be assumed that the covalent linkage increases the efficiency of conjugation by increasing the effective concentration of one component (presumably the DNA helicase) at its site of action.

[Nutritional support in patients with thoracic trauma. Usefulness of an enteral diet with a high fat content]. / Soporte nutricional en el paciente con trauma torácico. Utilidad de una dieta enteral con alto contenido en grasas.

The purpose of this study is to evaluate the effects and clinical tolerance of an enteral diet containing 55% "AET" in the form of fat and only 28% in the form of H. C. in a group of 17 polytraumatized patients admitted to the Intensive Care Unit with assisted ventilation as a result of thoracic traumatism. The average age of the patients was 36.6 +/- 17 years, and they remained in Intensive Care for more than 10 days. Energetic requirements were estimated at 1,800 +/- 180 Kcal per day. Enteral intake commenced on day 4.5 +/- 1.2 and 90% of the estimated requirements was achieved at 8.5 +/- 2.9 days. Average duration of the Enteral Nutrition was 15 +/- 3.7 days, Tolerance of the diet was considered good and problems due to intolerance leading to suspension of the diet were mainly related to worsening of the clinical condition. The volumen per minute expired per Kg of weight descended gradually and assisted ventilation was removed at 16 +/- 5.4 days, 5 patients died, mainly due to septic problems. There was a significant improvement in surviving patients with regard to levels of transferrin (p less than 0.01), prealbumin (p less than 0.001) and RBP (p less than 0.05), and no improvement was observed in the patients who had died. The nitrogenated balance was positive from the ninth day onwards in surviving patients, and remained negative in the patients who had died. In conclusion, this enteral diet with a high intake of fats, showed good tolerance and is beneficial in patients with thoracic traumas which require assisted ventilation.

[Evaluation of a clinical sign in predicting iron deficiency in women: the blue sclera]. / Valoración de un signo clínico en la predicción del déficit de hierro en la mujer: las escleróticas azules.

The purpose of this study was to calculate the predictive value (PV) of blue sclera (BS) in iron deficiency in women. The presence of this clinical sign was evaluated in 498 female patients at an urban primary care centre. Three observers independently evaluated the existence of BS on a scale of 0 to 3 in all female patients visited over a period of 35 weeks. Twenty eight cases of BS were detected over this period, of which 16 had ferropenia and 21 had anemia or iron deficiency. The positive predictive value of the clinical sign was 57.14%, 95% within the confidence interval of 52.77-61.51. The presence of BS was not affected by age or eye color. BS appears to be a good indicator of iron deficiency in our medium and, if confirmed by other studies, should be considered in the every-day clinical examination.