Background Controversial evidence has been reported regarding gender bias in the management of patients with acute coronary syndromes; thus, it is relevant to have data related to this topic in our country. Objective The aim of this study was to assess gender differences in the management of acute coronary syndromes in cardiovascular care units participating in the Epi-Cardio registry. Methods We included 8997 records of patients with diagnosis of acute coronary syndromes. Propensity score adjusted analyses and sensitivity analysis were performed. Results In patients with non ST-segment elevation acute coronary syndromes, women were independently associated with lower in-hospital indication of coronary angiography (OR 0.73, 95% CI 0.65 to 0.82), and lower use of IIb/IIIa inhibitors than men. After adjusted analyses, there were no significant differences between men and women in the use of reperfusion therapy for myocardial infarction or in in-hospital mortality. At discharge, women were significantly less likely than men to receive prescriptions for beta-blockers and statins, and more likely to receive prescriptions for benzodiazepines. Conclusions These findings suggest gender bias in the treatment of patients with acute coronary syndromes, evidenced by selection of a more conservative strategy and lower prescription of drugs recommended for secondary prevention in women. Differences between genders in the approach of acute coronary syndromes should be studied more deeply, as the underutili-zation of evidence-based therapies could have an impact on women clinical outcomes.

Introducción Existen evidencias controversiales sobre la existencia de sesgo de género en la atención de pacientes con síndromes coronarios agudos, y resulta relevante conocer datos de nuestro país al respecto. Objetivo Evaluar diferencias de género en la atención de síndromes coronarios agudos en las unidades de cuidados cardiovasculares participantes del registro Epi-Cardio. Material y métodos Se incluyeron 8.997 registros de pacientes con diagnóstico de síndrome coronario agudo. Se realizaron análisis ajustados y análisis de sensibilidad mediante puntaje de propensión. Resultados El género femenino estuvo asociado independientemente con menor indicación intrahospitalaria de cinecoronariografía (OR 0,73; IC 95% 0,65-0,82) y menor uso de inhibidores IIb/IIIa en pacientes con síndrome coronario agudo sin segmento ST elevado. Luego de análisis ajustados no hubo diferencia significativa en el uso de terapia de reperfusión en pacientes con infarto ni en mortalidad intrahospitalaria. Al alta, en comparación con los hombres, las mujeres tuvieron una probabilidad significativamente menor de recibir prescripciones de betabloqueantes y estatinas y mayor de recibir prescripciones de benzodiazepinas. Conclusiones Estos hallazgos sugieren la existencia de sesgo de género en el manejo de pacientes con síndrome coronario agudo, manifestado por la selección de estrategias más conservadoras y menor prescripción de fármacos recomendados en prevención secundaria a mujeres. Las diferencias en el abordaje de los síndromes coronarios agudos entre géneros deberían ser investigadas más profundamente, dado que la subutilización de terapias basadas en evidencias podría tener un impacto en la evolución clínica de las mujeres.

Background Patients with acute coronary syndrome have clinical differences which are determined by the age-group to which they belong. Yet, few studies have compared young patients versus elder patients presenting with this syndrome. Objectives To describe the clinical and angiographic characteristics, the therapeutic uses and the outcome of young patients with acute coronary syndrome, and to compare them with those of elder patients. Methods A total of 5,055 patients with diagnosis of acute coronary syn-drome, included in the Epi-Cardio registry, were analyzed. Men ≤ 45 years and women ≤ 50 years were considered young. Results Young patients represented 10.3% of the population (519) and 89.7% (4,536) were elder patients. Among young pa-tients, 49.9% presented ST-segment elevation acute coronary syndrome and 50.1% had non ST-segment elevation. In elder patients, ST-segment elevation acute coronary syndrome occurred in 38.4% and 61.6% had non ST-segment eleva-tion (p Conclusions ST-segment elevation acute coronary syndrome was more frequent among young patients compared to elder patients. Mortality was three to four times greater in elder patients. The difference in the clinical presentation is justified by the profile of cardiovascular risk and extension of coronary artery disease of both groups.

Introducción Los pacientes con síndrome coronario agudo presentan diferencias clínicas según el grupo etario al que pertenezcan. No obstante, son pocos los estudios que han comparado pacientes jóvenes versus mayores en el contexto de este síndrome. Objetivos Describir las características clínicas y angiográficas, los usos terapéuticos y el pronóstico de los pacientes jóvenes con síndrome coronario agudo y compararlos con los pacientes mayores. Material y métodos Se analizaron 5.055 pacientes incluidos en el registro Epi-Cardio con diagnóstico de síndrome coronario agudo. Se consideraron jóvenes los hombres ≤ 45 años y las mujeres ≤ 50 años. Resultados De los pacientes incluidos, 519 eran jóvenes (10,3%) y 4.536 eran mayores (89,7%). El 49,9% de los jóvenes presentaron síndrome coronario agudo con elevación del segmento ST y el 50,1% sin elevación del segmento ST. Entre los mayores, el 38,4% presentaron el síndrome con elevación del segmento ST y el 61,6% sin elevación del segmento ST (p < 0,00001). Se realizó cateterismo coronario a 2.845 pacientes (56,3%). Entre los jóvenes, el 54,2% tenían enfermedad significativa de un vaso, el 20% de dos vasos, el 9,7% de tres vasos y el 16,1% no tenían lesiones significativas. Entre los mayores, el 39,6% tenían enfermedad de un vaso, el 28,4% de dos vasos, el 22,5% de tres vasos y el 9,5% sin lesiones significativas (p < 0,001). No existieron diferencias significativas en los tratamientos entre ambos grupos etarios durante la internación. La mortalidad fue del 1% en jóvenes y del 3,5% en mayores (OR 0,26; p = 0,02). La mortalidad corregida fue significativamente menor entre los jóvenes (OR 0,25; p = 0,038). Conclusiones Los pacientes jóvenes con síndrome coronario agudo presentaron más frecuentemente elevación del segmento ST que los mayores. La mortalidad de los mayores fue tres a cuatro veces mayor que en los jóvenes. El perfil de riesgo cardiovascular y la extensión de la enfermedad coronaria de ambos grupos justifican la diferencia en la presentación clínica.

Shiga toxin (Stx)-producing Escherichia coli (STEC) colonizes the large intestine causing a spectrum of disorders, including watery diarrhea, bloody diarrhea (hemorrhagic colitis), and hemolytic-uremic syndrome. It is estimated that hemolytic-uremic syndrome is the most common cause of acute renal failure in infants in Argentina. Stx is a multimeric toxin composed of one A subunit and five B subunits. In this study we demonstrate that the Stx2 B subunit inhibits the water absorption (Jw) across the human and rat colonic mucosa without altering the electrical parameters measured as transepithelial potential difference and short circuit current. The time-course Jw inhibition by 400 ng/ml purified Stx2 B subunit was similar to that obtained using 12 ng/ml Stx2 holotoxin suggesting that both, A and B subunits of Stx2 contributed to inhibit the Jw. Moreover, non-hemorrhagic fluid accumulation was observed in rat colon loops after 16 h of treatment with 3 and 30 ng/ml Stx2 B subunit. These changes indicate that Stx2 B subunit induces fluid accumulation independently of A subunit activity by altering the usual balance of intestinal absorption and secretion toward net secretion. In conclusion, our results suggest that the Stx2 B subunit, which is non-toxic for Vero cells, may contribute to the watery diarrhea observed in STEC infection. Further studies will be necessary to determine whether the toxicity of Stx2 B subunit may have pathogenic consequences when it is used as a component in an acellular STEC vaccine or as a vector in cancer vaccines.

Adenylyl cyclase (AC) isoforms catalyze the synthesis of 3',5'-cyclic AMP from ATP. These isoforms are critically involved in the regulation of gene transcription, metabolism, and ion channel activity among others. Nitric oxide (NO) is a gaseous product whose synthesis from L-arginine is catalyzed by the enzyme NO synthase. It has been well established that NO activates the enzyme guanylyl cyclase, but little has been reported on the effects of NO on other important second messengers, such as AC. In the present study, the effects of sodium nitroprusside (SNP), a nitric oxide-releasing compound, on COS-7 cells transfected with plasmids containing AC types I, II, V and VI were evaluated. Total inhibition (~98.5%) of cAMP production was observed in COS-7 cells transfected with the AC I isoform and previously treated with SNP (10 mM) for 30 min, when stimulated with ionomycin. A high inhibition (~76%) of cAMP production was also observed in COS-7 cells transfected with the AC VI isoform and previously treated with SNP (10 mM) for 30 min, when stimulated with forskolin. No effect on cAMP production was observed in cells transfected with AC isoforms II and V.

Water channels or aquaporins (AQPs) have been identified in a large variety of tissues. Nevertheless, their role in the human gastrointestinal tract, where their action is essential for the reabsorption and secretion of water and electrolytes, is still unclear. The purpose of the present study was to investigate the structure and function of water channels expressed in the human colon. A cDNA fragment of about 420 bp with a 98% identity to human AQP3 was amplified from human stomach, small intestine and colon by reverse transcription polymerase chain reaction (RT-PCR) and a transcript of 2.2 kb was expressed more abundantly in colon than in jejunum, ileum and stomach as indicated by Northern blots. Expression of mRNA from the colon of adults and children but not from other gastrointestinal regions in Xenopus oocytes enhanced the osmotic water permeability, and the urea and glycerol transport in a manner sensitive to an antisense AQP3 oligonucleotide, indicating the presence of functional AQP3. Immunocytochemistry and immunofluorescence studies in human colon revealed that the AQP3 protein is restricted to the villus epithelial cells. The immunostaining within these cells was more intense in the apical than in the basolateral membranes. The presence of AQP3 in villus epithelial cells suggests that AQP3 is implicated in water absorption across human colonic surface cells.