Agustin Acosta | University of Dubrovnik (original) (raw)

Papers by Agustin Acosta

SEDEN Esta publicación no puede ser reproducida ni transmitida total o parcialmente, por ningún m... more SEDEN Esta publicación no puede ser reproducida ni transmitida total o parcialmente, por ningún medio, sin la autorización expresa por escrito de los titulares del copyright.

Intensive Care Medicine, 1992

Toxicon, 2010

In this study, three recombinant mojastin peptides (Moj-WN, Moj-NN, and Moj-DM) were produced and... more In this study, three recombinant mojastin peptides (Moj-WN, Moj-NN, and Moj-DM) were produced and compared functionally. Recombinant Moj peptides were purified as GST-fusions. GST-Moj-WN and GST-Moj-NN inhibited ADP-induced platelet aggregation in platelet rich plasma. The GST-Moj-WN had an IC 50 of 160 nM, while the GST-Moj-NN had an IC 50 of 493 nM. The GST-Moj-DM did not inhibit platelet aggregation. All three GST-Moj peptides inhibited SK-Mel-28 cell adhesion to fibronectin. The GST-Moj-WN inhibited the binding of SK-Mel-28 cells to fibronectin with an IC 50 of 11 nM, followed by the GST-Moj-NN (IC 50 of 28 nM), and the GST-Moj-DM (IC 50 of 46 nM). The GST-Moj peptides' ability to induce apoptosis on SK-Mel-28 cells was determined using Annexin-V-FITC and nuclear fragmentation assays. Cells were incubated with 5 μM GST-Moj peptides for 24 h. At 5 μM GST-Moj-DM peptide, 13.56% +/-2.08 of treated SK-Mel-28 cells were in early apoptosis. The GST-Moj-DM peptide also caused nuclear fragmentation as determined by fluorescent microscopy and Hoechst staining. The GST-Moj-WN and GST-Moj-NN peptides failed to induce apoptosis. We characterized the SK-Mel-28 integrin expression, as the first step in determining r-Moj binding specificity. Our results indicate that SK-Mel-28 cells express αvβ3, αv, α6, β1, and β3 integrin receptors.

Revista Internacional de Contaminación. Ambiental. Universidad Nacional Autónoma de México. rvp@a... more Revista Internacional de Contaminación. Ambiental. Universidad Nacional Autónoma de México. rvp@atmosfera.unam.mx. ISSN (Versión impresa): 0188-4999. MÉXICO. 2004. Agustín Gómez Álvarez / Arturo Villalba Atondo / Gildardo ...

Pace-pacing and Clinical Electrophysiology, 1983

Des stimulaleurs multiprogrammables AV séquentiels de type “double-demande” (DVI, MN) ont été imp... more Des stimulaleurs multiprogrammables AV séquentiels de type “double-demande” (DVI, MN) ont été implantés chez 23 patienls porteurs ?anomalies variées de tachycardies supraventriculaires. De plus, des stimuloteurs AV séquenfiels à paire “nonobligée” (DVI, MN e(DDD, M) ont été utilisés pour le traitement de lachyarhythmies ventriculaires. Nous avons observé que ľexpérience avec ee type de stimulateur multiprogrammable est favorable chez les patients sans fibrillation auriculaire chronique, qui ont besoin ?un stimutafeur et qui nécéssitent un froilement anti-tachycardique. Ľévolution des stimulateurs du type DDD contribuera sans doute à un traitement encore plus éfficace.Multi-programmable dual-demand AV sequential (DVI, MN) pacemakers were implanted in twenty-three potients (in one of them a DVI, MN unit was used as a VVI, MN with the aid of an atrial plug) with suproventricular tachycardias after electrophysiological studies revealed a great voriety of AV reentry circuits. The latter included tachycardios involving accessory pathways of the Kent type, manifest or concealed Wolff-Parkinson-White syndromes, nodo-ventricular (Mahaim) tracts, “enhanced” AV node for extra AV nodal) pothwaysand dual AV pathways. In addition, multiprogrammable “non-committed” AV sequential (DVI, MN and DDD, M) pacemakers were permanently implonted to treat different forms of ventricular tachyarrhythmias that included: torsode de pointes in the Romano-Ward syndrome and Chagas' cardiomyopathy, ventricular tachycordia which is bradycardia-dependent (in Chagas' cardiomyopathy) and reciprocal beats indueed by, and producing severe hemodynamic derangements in a patient with a conventional VVI unit. With smallsize multiprogrammable units, arrhythmias may be treated by changing parameters non-invasively. By temporary inhibition, one may analyze the underlying rhythm and pacemaker dependency. In potients without chronic atrial flutterJfibrillation who require pacing and possibly tachyarrhythmia control, our experience with multiprogrammable “non-committed” AV sequential pacing has been very satisfactory. The evolution toward newer pacing modes which provide atrial sensing and trackmg (DDD), and thus preserve AV synchrony over a wider range of atrial rates, may contribute even further to successful patient management. This may be applicable to pediatric patients as well.

Pace-pacing and Clinical Electrophysiology, 1998

Throughout a 9-month period during which 1, 125 Hoiter tapes were reviewed prospectively we ident... more Throughout a 9-month period during which 1, 125 Hoiter tapes were reviewed prospectively we identified 13 non medicated patients with an arrhythmia, which for the purposes of this presentation was categorized, because of their mode of initiation, as sudden Wenckebach periods (WP). The episodes emerged abruptly from a normal (± 200 ms) PR interval with sudden prolongation of PR and PP intervals (and reversed PR-RP relationship that took place over 1–8 cycles. The postpaced PR interval was shorter than that of the last conducted beat. The episodes were separated into two groups. Group I included 11 patients with symptoms other than syncope and Group 11 included 2 patients with syncope. There were 26 episodes of sudden WP in Group 1. Twenty-five terminated in a single (and one in double) blocked P waves. Most episodes occurred between 10 PM and 7 AM. Symptoms did not correlate with the episodes. Mean 24-hour rates were < 90. In Group II there were 22 episodes, all occurring between 6 AM and 10 PM. The mean sinus cycle lengths before the phenomenon started to occur in Group I (861 ± 185 ms) as well as the cycle lengths at the onset of block (1,096 ± 215 ms) were statistically longer than those in Group II (591 ± 40 ms and 747 ± 63 ms, respectively, P < 0.0001). Although the mode of onset in the episodes in Group II was similar to Group I, 16 episodes terminated in 2–6 blocked P waves. Thus, the entire number of episodes could be categorized as an unusual type (because of the PR prolongation) of paroxysmal, or advanced second degree A V block. Because these patients had negative electrophysiological studies, positive tilt tests, and absent syncope after oral propranolol therapy, they were considered as having neurocardiogenic syncope. In addition, the faster than normal (> 100) mean 24-hour rates) suggested that they also had so-called inappropriate sinus tachycardia. In summary. Group I consisted of patients with a normal, benign, vagal-induced second-degree AV block, whereas the Hoiter findings in Group II appeared to refiect unusual (but natural, i.e., nonprovoked) electrocardiographic manifestations of certain patients with neurocardiogenic syncope.

Cell Calcium, 2009

Sarcoplasmic reticulum contains the internal Ca 2+ store in smooth muscle cells and its lumen app... more Sarcoplasmic reticulum contains the internal Ca 2+ store in smooth muscle cells and its lumen appears to be a continuum that lacks diffusion barriers. Accordingly, the free luminal Ca 2+ level is the same all throughout the SR; however, whether the Ca 2+ buffer capacity is the same in all the SR is unknown. We have estimated indirectly the luminal Ca 2+ buffer capacity of the SR by comparing the reduction in SR Ca 2+ levels with the corresponding increase in [Ca 2+ ] i during activation of either IP 3 Rs with carbachol or RyRs with caffeine, in smooth muscle cells from guinea pig urinary bladder. We have determined that carbachol-sensitive SR has a 2.4 times larger Ca 2+ buffer capacity than caffeine-sensitive SR. Rapid inhibition of SERCA pumps with thapsigargin revealed that this pump activity accounts for 80% and 60% of the Ca 2+ buffer capacities of carbachol-and caffeine-sensitive SR, respectively. Moreover, the Ca 2+ buffer capacity of carbachol-sensitive SR was similar to caffeine-sensitive SR when SERCA pumps were inhibited. Similar rates of Ca 2+ replenishments suggest similar levels of SERCA pump activities for either carbacholor caffeine-sensitive SR. Paired pulses of caffeine, in conditions of low Ca 2+ influx, indicate the relevance of luminal SR Ca 2+ buffer capacity in the [Ca 2+ ] i response. To further study the importance of luminal SR Ca 2+ buffer capacity in the release process we used low levels of heparin to partially inhibit IP 3 Rs. This condition revealed carbachol-induced transient increase of luminal SR Ca 2+ levels provided that SERCA pumps were active. It thus appears that SERCA pump activity keeps the luminal SR Ca 2+ -binding proteins in the high-capacity, low-affinity conformation, particularly for IP 3 R-mediated Ca 2+ release.

American Journal of Cardiology, 1998

Analysis of heart rate variability in patients with inappropriate sinus tachycardia showed a 24-h... more Analysis of heart rate variability in patients with inappropriate sinus tachycardia showed a 24-hour decrease in all temporal and spectral indexes, even after attempted correction to a rate of 75 beats/min. This may have resulted from a global decrease in parasympathetic activity or from a rapid sinus rate produced by other ill-defined mechanisms.

Kidney International, 2005

A number of cross-sectional or serial studies have demonstrated the clinical impact of microprote... more A number of cross-sectional or serial studies have demonstrated the clinical impact of microproteinuria and macroproteinuria by identifying individuals at risk of both end-stage renal disease and major cardiovascular events. This study focused on the prevalence of proteinuria in Mexico and its relationship with other cardiovascular risk factors such as hypertension, type 2 diabetes mellitus, body mass index, smoking, age, and gender. The prevalence of proteinuria in Mexico was obtained from the probabilistic cross-sectional national health survey performed in the year 2000. The proportion of urine dipstick samples that tested positive for protein (defined as &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1+) in adults from 20 to 69 years of age was determined. The analysis was performed using both algebraic and multicategorical models. Potential interactions between proteinuria and other major cardiovascular risk factors were investigated. A total of 46,523 adult survey participants were included in the analysis. In the general population, 9.2% had proteinuria. By univariate, multivariate, and multicategorical analysis, hypertension, diabetes, obesity, and age were strongly associated with the prevalence of proteinuria (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). However, in Mexico, the specific distribution of age groups demonstrated that the absolute number of patients without hypertension that had proteinuria is not irrelevant. To identify 1 case of proteinuria, one would need to screen 3 persons with diabetes mellitus, 5 patients with hypertension without diabetes, or 6 persons over the age of 55 years. When proteinuria is present, the probability of having a noncommunicable chronic disease or other major cardiovascular risk factor is more than 85%. Proteinuria is prevalent. When considered together, dipstick-positive proteinuria, blood pressure level, body mass index &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =30 m(2)/kg, and abnormal fasting blood glucose measured on a single occasion identifies different segments of the population. Studies such as this may be a suitable initial clinical approach to general population screening for renal and cardiovascular risk stratification.