Time-course of transcriptome response to respiratory syncytial virus infection in lung epithelium cells.

Respiratory syncytial virus (RSV) is the major cause of acute lower respiratory tract infection in infants. Winter outbreaks in Chile result in 5% of infected children hospitalized, with 0.01% mortality. Increased evidence indicates that viral and host factors modulate the severity of infection. Using DNA microarrays, we characterized the genome-wide transcriptional response of lung mucoepidermoid cells (NCI-H292) at 0, 24, 48, 72 and 96 hours post-infection (hpi) with a single dose of RSV/A. During the whole studied period, a bi-phasic gene expression profile was observed by a total of 330 differentially expressed genes. About 60% of them were up-regulated between 24-72 hpi and then turned-off at 96 hpi. This transient, early gene expression pattern was significantly enriched in biological processes like interferon signaling, antigen processing and presentation, double-stranded RNA binding and chemokine activity. We detected 27 common genes up-regulated between 24-72 hpi, from which IFIT1, IFI44, MX1, CXCL11 and OAS1 had the highest expression. The second pattern comprised over 120 genes, which remained silenced until 72 hpi, but were steeply up-regulated by 96 hpi. Biological processes of this late-response profile included cell cycle division and microtubule cytoskeleton organization. Conversely, the genes belonging to virus response pathway showed a decreased expression at 96 hpi. We conclude that RSV induces an early innate immune activation profile response until 72 hpi. Thereafter, the viral response is inhibited, leading to host cell recovery. The presented cellular model allows to study the specific pathways involved in elimination of infection at prolonged time intervals and their subsequent analysis in severe RSV disease of infants and/or older adults.

MUC1/SEC and MUC1/Y overexpression is associated with inflammation in Sjögren's syndrome.

OBJECTIVES: To evaluate the expression and localization of MUC1/SEC and MUC1/Y isoforms in labial salivary glands (LSG) from Sjögren's syndrome patients (SS patients), as well as their in vitro expression induced by cytokines. SUBJECTS AND METHODS: Labial salivary gland from 27 primary SS patients and 22 non-SS sicca subjects were studied. Relative MUC1/SEC and MUC1/Y mRNA levels were determined by qPCR and protein levels by Western blotting. Induction of mucin mRNAs was assayed in vitro. Immunohistochemistry was used for localization. RESULTS: Relative MUC1/SEC and MUC1/Y mRNA and protein levels were significantly higher in LSG from SS patients. These mRNAs were induced by cytokines. MUC1/SEC and MUC1/Y were detected in acini apical region of control LSGs, and significant cytoplasmic accumulation was observed in acini of SS patients. MUC1/Y localized in acinar nuclei and cytoplasm of inflammatory cells of LSG from SS patients. A strong positive correlation was observed between cellular MUC1/SEC levels and glandular function determined by scintigraphy. CONCLUSIONS: We show for the first time that MUC1/SEC and MUC1/Y are expressed in LSG of both SS patients and non-SS sicca subjects. The observed overexpression and aberrant localization of MUC1/SEC and MUC1/Y and their induction by pro-inflammatory cytokines may favor the perpetuation of the inflammatory environment that disrupts the salivary glandular homeostasis in SS patients.

Sjögren's syndrome and the epithelial target: a comprehensive review.

The most difficult component in our understanding of human autoimmunity remains a rigorous dissection of etiological events. Indeed, the vast literature on autoimmune diseases focuses on the inflammatory response, with the hope of developing drugs that reduce inflammation. However, there is increasing recognition that understanding the immunobiology of target tissues will also have direct relevance to disease natural history, including breach of tolerance. Sjögren's syndrome is essentially an epitheliitis and there are major changes to normal architectural salivary organization. We propose that loss of homeostasis is the initial event that precipitates inflammation and that such inflammatory response includes not only the adaptive response, but also an intense innate immune/bystander response. To understand these events this review focuses on the architecture, phenotype, function and epithelial cell organization. We further submit that there are several critical issues that must be defined to fully understand epithelial cell immunobiology in Sjögren's syndrome, including defining epithelial cell polarity, cell-cell and cell to extracellular matrix interactions and a variety of chemical and mechanical signals. We also argue that disruption of tight junctions induces disorganization of the apical pole of salivary acinar cells in Sjögren's syndrome. In addition, there will be a critical role of inflammatory cytokines in the apico-basal relocation of tight junction proteins. Further, the altered disorganization and relocation of proteins that participate in secretory granule formation are also dysregulated in Sjögren's syndrome and will contribute to abnormalities of mucins within the extracellular matrix. Our ability to understand Sjögren's syndrome and develop viable therapeutic options will depend on defining these events of epithelial cell biology.

Nerve growth factor stimulates cellular proliferation of human epithelial ovarian cancer.

Due to its ability to induce vascular endothelial growth factor expression and proliferation, migration, and vasculogenesis of endothelial cells, nerve growth factor (NGF) has been considered as an angiogenic factor in epithelial ovarian cancer (EOC). In this work, we evaluated the angiogenic and proliferative mRNA expression profiles of EOC and addressed the responsiveness of EOC explants to NGF stimulation. Twenty EOC samples were obtained from Obstetrics and Gynecology Department, University of Chile's Clinical Hospital. Global gene expression profiles of selected poorly differentiated serous EOC samples were obtained with DNA oligonucleotide microarrays. In addition, EOC explants were subjected to NGF stimulation and levels of p-AKT, BAX, BCL2, Ki-67, c-MYC, and FOXL2 proteins were determined by immunohistochemistry. Results showed that mRNAs coding for specific transcriptional regulators and antiapoptotic components of the NGF signaling pathway were upregulated in EOC cells. At the protein level, key members of the NGF pathway including p-AKT, BCL2/BAX, Ki-67, and c-MYC were found increased, while FOXL2 was decreased in response to NGF stimulation. These findings strongly suggest that NGF stimulates cellular proliferation of human EOC.

Identification of genes related to nitrogen uptake in wine strains of Saccharomyces cerevisiae.

The yeast Saccharomyces cerevisiae is the main microorganism responsible for wine fermentation and its development influences the quality of wine. A problem affecting these types of fermentations, generating important losses in this industry, are the slow or stuck fermentations which may result from low nitrogen availability in the must. Therefore, several studies have been directed towards identifying genes involved in nitrogen metabolism using high throughput strategies which include subjecting the yeast to changes in the type or concentration of the available nitrogen source. However, this type of approach can also generate responses in the yeast that do not necessarily alter the expression of genes related to nitrogen metabolism. In this work, by using intraspecific hybridisation of wild wine yeast strains we obtained genetically and oenologically similar strains with differences in the consumption of nitrogen sources. Using the same must, the global expression patterns of these yeasts were compared by microarrays, the analysis of which identified 276 genes that varied in their expression between the strains analysed. The functional analysis of the genes with a known function indicates that some participate in nitrogen metabolism, alcoholic fermentation, ion transport and transcriptional regulation. Furthermore, differences were observed in the expression of genes which have been partially associated to nitrogen, as in the case of ZRT1 and ATO2. Interestingly, many of the genes identified have no known function or have not been previously associated to this phenotype.

Genomic and phenotypic comparison between similar wine yeast strains of Saccharomyces cerevisiae from different geographic origins.

AIMS: To study genomic and phenotypic changes in wine yeasts produced in short time periods analysing yeast strains possibly derived from commercial strains recently dispersed. METHODS AND RESULTS: We conducted a genomic and phenotypic comparison between the commercial yeast strain EC1118 and two novel strains (LV CB and L-957) isolated from different wine areas industrially intervened <20 years ago. Molecular analysis by amplified fragment length polymorphism (AFLP) and RAPD-PCR was not able to distinguish between these strains. However, comparative genomic hybridization (aCGH) showed discrete DNA gains and losses that allowed unequivocal identification of the strains. Furthermore, analysis of aCGH data supports the hypothesis that strains LV CB and L-957 are derivatives from strain EC1118. Finally, scarce phenotypic differences in physiological and metabolic parameters were found among the strains. CONCLUSION: The wine yeasts have a very dynamic genome that accumulates changes in short time periods. These changes permit the unique genomic identification of the strains. SIGNIFICANCE AND IMPACT OF THE STUDY: This study permits the evaluation of microevolutive events in wine yeasts and its relationship with the phenotype in this species.

Gene regulation by BCL3 in a cervical cancer cell line.

BCL3 is a putative proto-oncogene deregulated in haematopoieitic and solid tumours. It has been suggested that its oncogenic effects could be mediated, at least in part, by inducing proliferation and inhibiting cell death. To provide more insight into the mediators of these effects, we used an unbiased approach to analyse the mRNA expression changes after knocking-down BCL3 using specific shRNAs. One hundred eighty genes were up-regulated and sixtynine genes were down-regulated after knocking down BCL3. Function analyses showed enrichment in genes associated with cellular growth and proliferation, cell death and gene expression. We found that STAT3, an important oncogene in human cancer, was the central node of one of the most significant networks. We validated STAT3 as a bona fide target of BCL3 by additional interference RNA and in silico analyses of previously reported lymphoma patients.

Oxidation reactions catalyzed by manganese peroxidase isoenzymes from Ceriporiopsis subvermispora.

A total of 11 manganese peroxidase isoenzymes (MnP1-MnP11) with isoelectric points (pIs) in the range of 4.58-3.20 were isolated from liquid- and solid-state cultures of the basidiomycete Ceriporiopsis subvermispora. In the presence of hydrogen peroxide, these isoenzymes showed different requirements for Mn(II) in the oxidation of vanillylacetone, o-dianisidine, p-anisidine and ABTS, whereas oxidation of guaiacol by any isoenzyme did not take place when this metal was omitted. Km values for o-dianisidine and p-anisidine in the absence of Mn(II) are in the range of 0.5-1.0 mM and 4.5-42.0 mM, respectively. Oxalate and citrate, but not tartrate, accelerate the oxidation of o-dianisidine, both in the presence and in the absence of Mn(II). MnPs from this fungus are able to oxidize kojic acid without externally added hydrogen peroxide, indicating that they can also act as oxidases. In this reaction, however, the requirement for Mn(II) is absolute.

Plasma polyphenols and antioxidants, oxidative DNA damage and endothelial function in a diet and wine intervention study in humans.

An intervention study was performed to evaluate the influence of a Mediterranean diet, a high fat diet, and their supplementation with red wine in moderate amounts, on biochemical, physiological, and clinical parameters related to atherosclerosis and other chronic diseases. For 3 months two groups of 21 male volunteers each, received either a Mediterranean diet or a high fat diet; during the second month, red wine was added isocalorically, 240 ml/day. Participants were kept under close medical and nutritional surveillance. At days 0, 30, 60 and 90, clinical, physiological and biochemical evaluations were made. Plasma vitamin C was significantly decreased in the high fat diet group compared to the Mediterranean diet group. After wine supplementation to the Mediterranean diet, a significant 13.5% increase in plasma vitamin C was observed. Furthermore, when wine was added vitamin E decreased significantly in plasma, 15% in the high fat diet and 26% in the Mediterranean diet. Total plasma antioxidant capacity (total antioxidant reactivity) increased 28% above basal levels in the Mediterranean diet group, but not in the high fat diet group. In both groups, wine induced a marked increase in total antioxidant reactivity above basal levels, 56% and 23%, respectively. Oxidative DNA damage, detected as 8-hydroxydeoxyguanosine (8-OHdG) levels in blood leukocyte DNA, was markedly increased by the high fat diet; however, it was strongly reduced, to approximately 50% basal values, after wine supplementation, both in the high fat diet and Mediterranean diet groups. Endothelial function, evaluated noninvasively as flow-mediated vascular reactivity of the brachial artery, was suppressed by the high fat diet, and was normal after wine supplementation. These effects are attributed to oxidative stress associated with a high fat diet, and to the elevated plasma antioxidant capacity associated with wine consumption and the Mediterranean diet. The results presented support the following conclusions: a high fat diet induces oxidative stress; a diet rich in fruits and vegetables enhances antioxidant defenses; wine supplementation to a high fat or a Mediterranean diet increases plasma antioxidant capacity, decreases oxidative DNA damage, and normalizes endothelial function.

Oral dryness in Sjögren's syndrome patients. Not just a question of water.

Sjögren's syndrome (SS) is a chronic autoimmune disease of undefined etiology. Patients with this syndrome suffer from severe alterations in both the quality and quantity of saliva and tears, due to impaired function of the relevant exocrine glands. Prevalent symptoms experienced by SS-patients include a persistent dry mouth sensation (xerostomia) and dry eyes (keratoconjunctivitis sicca). Water content of saliva depends of acetylcholine levels, glandular innervation, M3R signaling, calcium tunneling and water release, among other factors. However, unstimulated salivary flow correlates only poorly with symptoms of mouth dryness, raising the question as to which other components of saliva may be involved in mouth dryness experienced by SS-patients? Salivary mucins are glycoproteins characterized by the presence of large oligosaccharide side chains attached to the protein backbone. These molecules are key saliva components that are required to sequester water and thereby moisturize, as well as lubricate the oral mucosa. In the labial salivary glands of SS patients, morphological and functional alterations are detectable that affect the maturation and trafficking of salivary mucins. In this review, we will focus the discussion on these aspects of reduced salivary flow and decreased quality of salivary mucins, since they are likely to be responsible for xerostomia in SS-patients.

[Partial or total replacement of the aortic arch. Experience in 23 patients]. / Reemplazo parcial o total del arco aórtico. Experiencia en 23 pacientes.

BACKGROUND: Surgery of the aortic arch is a very complex procedure since it requires protective strategies for the brain, heart and rest of the body. AIM: To communicate our experience in the first 23 total or partial replacements of aortic arch. MATERIAL AND METHODS: Retrospective search in the database of the Cardiovascular Surgery Unit for patients subjected to partial or total replacement of the aortic arch since 1998. RESULTS: Between 1988 and 2002, 23 patients were operated. Seventeen had aortic dissection (10 acute and 7 chronic), five had an atherosclerotic aneurysm and one had a traumatic lesion. Thirteen patients were subjected to a replacement of the arch plus ascending aorta, six to a replacement of the arch plus descending aorta and four to a replacement of the arch, ascending and descending aorta. Seven patients had previous operation of the thoracic aorta. Arterial perfusion was done via the femoral artery, axillary artery or a combination of both. A hypothermic circulatory arrest was induced in 22; it was associated with cerebral retro perfusion alone in 8 patients, antegrade cerebral perfusion in 5; isolated or associated axillary perfusion was used in five patients. In seven, procedures on the aortic or mitral valve, or coronary artery operations were added. Operative mortality was 26%, 3 of the 8 patients operated as an emergency and 3 of 15 elective operations. There was no mortality among those without dissection and of 7 chronic dissections, one died. All patients were followed for an average of 45 months. Two patients required reinterventions on the aorta and one for colon cancer. There was one late death of unknown cause. Postoperative complications were agitation, bleeding and temporary vocal cord dysfunction. CONCLUSIONS: There is a learning curve, where more extensive operations, particularly those done as emergency or for dissections, had an increased operative risk.

Manganese Peroxidase-Dependent Oxidation of Glyoxylic and Oxalic Acids Synthesized by Ceriporiopsis subvermispora Produces Extracellular Hydrogen Peroxide.

The ligninolytic system of the basidiomycete Ceriporiopsis subvermispora is composed of manganese peroxidase (MnP) and laccase. In this work, the source of extracellular hydrogen peroxide required for MnP activity was investigated. Our attention was focused on the possibility that hydrogen peroxide might be generated by MnP itself through the oxidation of organic acids secreted by the fungus. Both oxalate and glyoxylate were found in the extracellular fluid of C. subvermispora cultures grown in chemically defined media, where MnP is also secreted. The in vivo oxidation of oxalate was measured; CO(2) evolution was monitored after addition of exogenous [C]oxalate to cultures at constant specific activity. In standard cultures, evolution of CO(2) from oxalate was maximal at day 6, although the MnP titers were highest at day 12, the oxalate concentration was maximal (2.5 mM) at day 10, and the glyoxylate concentration was maximal (0.24 mM) at day 5. However, in cultures containing low nitrogen levels, in which the pH is more stable, a better correlation between MnP titers and mineralization of oxalate was observed. Both MnP activity and oxidation of [C]oxalate were negligible in cultures lacking Mn(II). In vitro assays confirmed that Mn(II)-dependent oxidation of [C]oxalate by MnP occurs and that this reaction is stimulated by glyoxylate at the concentrations found in cultures. In addition, both organic acids supported phenol red oxidation by MnP without added hydrogen peroxide, and glyoxylate was more reactive than oxalate in this reaction. Based on these results, a model is proposed for the extracellular production of hydrogen peroxide by C. subvermispora.

Kinetics of Mn3+-oxalate formation and decay in reactions catalyzed by manganese peroxidase of Ceriporiopsis subvermispora.

The kinetics of Mn3+-oxalate formation and decay were investigated in reactions catalyzed by manganese peroxidase (MnP) from the basiomycete Ceriporiopsis subvermispora in the absence of externally added hydrogen peroxide. A characteristic lag observed in the formation of this complex was shortened by glyoxylate or catalytic amounts of Mn3+ or hydrogen peroxide. MnP titers had a minor effect on this lag and did not influence the decay rate of the complex. In contrast, Mn2+ and oxalate drastically affected maximal concentrations of the Mn3+-oxalate complex formed, the decay of which was accelerated at high Mn2+ levels. The highest concentration of complex was obtained at pH 4.0, whereas an inverse relationship was found between the pH of the reaction and the decay rate of the complex with MnP present. In the absence of MnP, the best fit for the decay kinetics of the complex gave an order of 3/2 at concentrations in the range of 30-100 microM, with a kobs = 0.012 min-1 M-0.5 at pH 4.0. The rate constant increases at lower pH values and decreases at high oxalate concentrations. The physiological relevance of these findings is discussed.

Oxalate oxidase from Ceriporiopsis subvermispora: biochemical and cytochemical studies.

The enzyme oxalate oxidase was identified in mycelial extracts of the basidiomycete Ceriporiopsis subvermispora and thereafter purified to homogeneity. The purification procedure included only three steps: Q-Sepharose chromatography, precipitation at pH 3.0, and phosphocellulose chromatography. The enzyme is a 400-kDa homohexamer, as determined by gel permeation in Sephadex G-200 and SDS-polyacrylamide gel electrophoresis. Isoelectrofocusing revealed a pI of 4.2. Optimal activity was obtained at pH 3.5 and at 45 degrees C. The purified enzyme has Km and kcat values of 0.1 mM and 88 s-1, respectively. It is highly specific for oxalate, although it is inhibited at concentrations of this substrate above 2.5 mM. Hystochemistry studies conducted over mycelium slices showed reactions products in both endocellular and periplasmic associated elements. A possible connection between the intracellular metabolism of oxalate and the extracellular ligninolytic activity of the fungus is proposed.

U1 and U2 snRNA are localized in the sperm nucleus.

Analysis of epididymal rat sperm RNA strongly suggested the presence of U snRNAs, especially U1 and U2 snRNA. By Northern blot analysis with radiolabeled oligodeoxynucleotide probes, the presence of U1 and U2 snRNA in rat sperm was confirmed. To precisely localize these RNAs, in situ hybridization with antisense and sense oligo probes labeled with digoxigenin was carried out. The results indicate that U1 as well as U2 snRNA are confined to the sperm nucleus.

Reemplazo parcial o total del arco aórtico: Experiencia en 23 pacientes / Partial or total replacement of the aortic arch: Experience in 23 patients

Background: Surgery of the aortic arch is a very complex procedure since it requires protective strategies for the brain, heart and rest of the body. Aim: To communicate our experience in the first 23 total or partial replacements of aortic arch. Material and methods: Retrospective search in the database of the Cardiovascular Surgery Unit for patients subjected to partial or total replacement of the aortic arch since 1998. Results: Between 1988 and 2002, 23 patients were operated. Seventeen had aortic dissection (10 acute and 7 chronic), five had an atherosclerotic aneurysm and one had a traumatic lesion. Thirteen patients were subjected to a replacement of the arch plus ascending aorta, six to a replacement of the arch plus descending aorta and four to a replacement of the arch, ascending and descending aorta. Seven patients had previous operation of the thoracic aorta. Arterial perfusion was done via the femoral artery, axillary artery or a combination of both. A hypothermic circulatory arrest was induced in 22; it was associated with cerebral retro perfusion alone in 8 patients, antegrade cerebral perfusion in 5; isolated or associated axillary perfusion was used in five patients. In seven, procedures on the aortic or mitral valve, or coronary artery operations were added. Operative mortality was 26%, 3 of the 8 patients operated as an emergency and 3 of 15 elective operations. There was no mortality among those without dissection and of 7 chronic dissections, one died. All patients were followed for an average of 45 months. Two patients required reinterventions on the aorta and one for colon cancer. There was one late death of unknown cause. Postoperative complications were agitation, bleeding and temporary vocal cord dysfunction. Conclusions: There is a learning curve, where more extensive operations, particularly those done as emergency or for dissections, had an increased operative risk.

Inducción anestésica en cirugía carotídea: comparación entre dos técnicas / Anesthetic induction in carotid surgery: comparasion between 2 techniques

Los pacientes sometidos a cirugía carotídea tienen un mayor riesgo cardiovascular. Esto y las características de la cirugía hacen deseable una óptima estabilidad hemodinámica en el intra y posoperatorio. El objetivo fue comparar dos técnicas de inducción anestésica en pacientes sometidos a endarterectomía carotídea electiva, en relación a la respuesta hemodinámica durante los períodos: posinducción, posintubación, preincisión y posincisión estandarizados previamente y condiciones de extubación al final de la cirugía. Un total de 21 pacientes fueron aleatoriamente asignados a uno de dos esquemas de inducción. Grupo I (G I)(n=10) Fentanyl 5µgrùkg-1 más Tiopental 4 mgùkg-1 y Grupo II (G II)(n=11) Alfentanil 120 µgrùkg-1. Entre grupos hubo diferencia sólo en los valores de PA, IC y LVSWI en el período posinducción. En ambos grupos hubo un descenso significativo en PA, IC y LVSWI en los períodos preincisión y posincisión. En el G II disminuyó, además, la FC presentándose un caso de bricardia extrema de difícil tratamiento. Dos pacientes, uno de cada grupo, no fueron estubados por no cumplir los criterios prefijados. La inducción con Alfentanil mostró menos variabilidad hemodinámica entre los períodos de medición, aunque la tendencia en ambos grupos fue al descenso de la PA hacia los períodos finales de estudio. La extubación fue comparable

Reemplazo de la aorta ascendente y válvula aórtica con reimplante de las arterias coronarias / Replacement of the ascending aorta and aortic valve with reimplantation of the coronary arteries

La reparación paliativa de los aneurismas de la aorta ascendente tiene una recidiva alta por tratarse de una patología degenerativa que compromete la aorta desde el anillo valvular. Actualmente se prefiere el tratamiento definitivo que consiste en el reemplazo de la aorta ascendente junto con la válvula aórtica. Entre marzo de 1978 y octubre de 1983 hemos intervenido 8 pacientes con esta patología. Cinco casos presentaban disección de la aorta de tipo proximal y 2 se operaron en etapa aguda. La indicación operatória fue insuficiencia aórtica grave en 6 pacientes y disección aguda en los 2 restantes. La reparación del aneurisma se realizó con prótesis de dacrón que tiene incorporada una válvula de Bejork-Shiley sobre la cual se reimplantaron los ostia coronarios. El estudio histológico de la aorta demostró necrosis quística de la túnica media en todos los casos. Dos pacientes fallecieron por complicaciones quirúrgicas y los 6 restantes fueron dados de alta bien. El control alejado (x = 21,6 meses) reveló que 5 pacientes están asintomáticos y sin recidiva, 1 falleció a los 15 meses. La técnica de esta grave patología con buenos resultados alejados y sin recidivas

Evolución de las indicaciones, técnica quirúrgica y resultados de la revascularización miocárdica / Changes in the indications, surgical techniques and results of myocardial revascularization surgery

Durante los últimos 20 años, las indicaciones y técnica quirúrgica de la revascularización miocárdica han evolucionado en forma importante, por lo cual nos ha interesado estudiar estos cambios y su influencia sobre los resultados obtenidos en pacientes sometidos a este tratamiento quirúrgico. Con este objeto, se analizaron los factores clínicos (edad, capacidad funcional, antecedentes mórbidos, factores de riesgo y patologías asociadas), la cinecoronariografía selectiva, la técnica quirúrgica, y los resultados de la intervención (mortalidad, morbilidad y estadía hospitalaria) de 400 pacientes de un total de 2.410 casos intervenidos entre 1970-1990. Estos pacientes fueron divididos en cuatro grupos que incluyen los primeros cien pacientes operados en forma consecutiva de puente aortocoronario exclusivo (electivos o urgencias) durante los años 1975 (grupo I), 1980 (grupo II), 1985 (grupo III) y 1990 (grupo IV). Los cambios observados en la técnica quirúrgica incluyeron el uso progresivamente mayor de la arteria mamaria interna (20%, 12%, 60%, 86%, respectivamente), el uso de magnificación óptica en el grupo II y siguientes y luego hipotermia a 25§C y cardioplejía usados en los grupos III y IV. La edad promedio, el porcentaje de pacientes mayores de 70 años, de pacientes intervenidos con infarto reciente (<30 días) de enfermos con lesión de tres vasos, y de pacientes que recibieron tres o más puentes aortocoronarios, fueron progresivamente mayores en el tiempo, y comparados los grupos entre sí, la diferencia tuvo significancia estadística (p<0,001). En cambio, la estadía intrahospitalaria postoperatoria fue decreciente durante el período analizado (14, 12, 9 y 9 días, respectivamente) y la morbilidad y mortalidad permanecieron estables, esta última en el 1%. Concluimos que la cirugía de revascularización miocárdica se ha ido efectuando en pacientes progresivamente más graves y con factores de riesgo mayores, manteniendo la morbimortalidad estable

Acceso auricular izquierdo traseptal y superior combinado / Transeptal left auricular access and up combinated

El acceso auricular izquierdo clásico, por detrás y paralelo al surco interauricular, no permite una buena exposición de la válvula mitral cuando la aurícula izquierda es de tamaño normal o sólo ligeramente aumentado. En reoperaciones, este acceso auricular izquierdo requiere de mayor disección del corazón, además, en esta situación, el anillo mitral se fija en una posición de más difícil exposición. Entre diciembre 1991 y octubre 1992, 25 pacientes fueron operados con un nuevo acceso auricular izquierdo transeptal y superior combinado. Se efectuaron 23 procedimientos mitrales (7 reoperaciones), en 8 casos asociados a otros procedimientos quirúrgicos cardiovasculares, una sección de Haz paraespecífico lateral izquierdo y una resección de mixoma auricular izquierdo. La técnica consiste en una amplia auriculotomía derecha, paralela y a 1,5 cm al surco aurículo-ventricular, exponiendo el tabique interauricular totalmente, el que es incidido desde el limbo inferior de la fosa ovalis hasta la incisión auricular derecha previa, extendiendo luego la incisión por el techo de la aurícula izquierda. En todos los casos se obtuvo un excelente acceso a la cavidad auricular izquierda y una muy buena exposición de la válvula mitral. No se produjeron desgarros de la pared auricular izquierda. No hubo hemorragia intraoperatoria por líneas de suturas y ningún paciente fue reexplorado por sangrado postoperatorio. El control ecocardiográfico no demostró comunicación interauricular residual en ningún caso. No hubo trastornos permanentes de la conducción aurículo-ventricular. No se observó una prolongación mayor del tiempo operatorio total, y en reoperaciones se requirió de menor disección del corazón. Este nuevo abordaje auricular izquierdo permite un excelente acceso a la aurícula izquierda, especialmente cuando ésta es de tamaño normal o ligeramente aumentado, y en reoperaciones cardíacas, y por lo tanto una muy buena exposición de la válvula mitral, sin distorsionar ninguna de las estructuras de ésta. La técnica no prolonga el procedimiento operatorio y no tiene morbilidad intrínseca