The mechanochemical synthesis of PbTe nanostructures: following the Ostwald ripening effect during milling.

A fundamental understanding of the Ostwald ripening effect (ORE) during the mechanochemical synthesis of PbTe nanostructures is presented. The ripening process involves the coarsening of larger particles from those of smaller size; this phenomenon was systematically evaluated at different stages of milling by microscopy analyses (AFM, TEM, STEM and HRTEM). At the early stage of milling, smaller particles and quantum dots are eventually dissolved to lower the total energy assciated with their surfaces. The ripening process - during milling - involves short-range mass transfer among particles. HRTEM analyses allowed us to identify that coarsening occurs by thermo-mechanically activated cooperative mechanisms. The detachment of the atoms from smaller particles to form bigger ones plays a major role in the particle coarsening. It was found that the coarsening process was not limited to crystalline nanostructures; so grain boundaries, edge dislocations and boundaries among crystalline and amorphous phases also play an important role to determine how species migration contributes to generate coarse particles. Those serve as sites for inducing coarsening in an equivalent way as surfaces do. Secondary ion mass spectrometry and elemental chemical mapping (EDX-STEM) revealed that both the purity and the chemical homogeneity of the PbTe nanostructures are prominent features of this material. Additionally, a direct band gap enhancement (780 nm) compared to bulk PbTe (3859 nm) was detected. It occurred due to the quantum confinement effect, lattice imperfections and even surface properties of the nanostructures. It is important to point out that the whole optical behaviour of the PbTe nanostructures was dependent upon the embedded nanoparticles and quantum dots in the clusters and coarse particles ranging from 15 nm to 35 nm.

Helicobacter pylori second-line rescue therapy with levofloxacin- and bismuth-containing quadruple therapy, after failure of standard triple or non-bismuth quadruple treatments.

BACKGROUND: The most commonly used second-line Helicobacter pylori eradication regimens are bismuth-containing quadruple therapy and levofloxacin-containing triple therapy, both offering suboptimal results. Combining bismuth and levofloxacin may enhance the efficacy of rescue eradication regimens. AIMS: To evaluate the efficacy and tolerability of a second-line quadruple regimen containing levofloxacin and bismuth in patients whose previous H. pylori eradication treatment failed. METHODS: This was a prospective multicenter study including patients in whom a standard triple therapy (PPI-clarithromycin-amoxicillin) or a non-bismuth quadruple therapy (PPI-clarithromycin-amoxicillin-metronidazole, either sequential or concomitant) had failed. Esomeprazole (40 mg b.d.), amoxicillin (1 g b.d.), levofloxacin (500 mg o.d.) and bismuth (240 mg b.d.) was prescribed for 14 days. Eradication was confirmed by (13) C-urea breath test. Compliance was determined through questioning and recovery of empty medication envelopes. Incidence of adverse effects was evaluated by questionnaires. RESULTS: 200 patients were included consecutively (mean age 47 years, 67% women, 13% ulcer). Previous failed therapy included: standard clarithromycin triple therapy (131 patients), sequential (32) and concomitant (37). A total of 96% took all medications correctly. Per-protocol and intention-to-treat eradication rates were 91.1% (95%CI = 87-95%) and 90% (95%CI = 86-94%). Cure rates were similar regardless of previous (failed) treatment or country of origin. Adverse effects were reported in 46% of patients, most commonly nausea (17%) and diarrhoea (16%); 3% were intense but none was serious. CONCLUSIONS: Fourteen-day bismuth- and levofloxacin-containing quadruple therapy is an effective (≥90% cure rate), simple and safe second-line strategy in patients whose previous standard triple or non-bismuth quadruple (sequential or concomitant) therapies have failed.

Treatment of refractory cholestatic pruritus with molecular adsorbent recirculating system (MARS).

UNLABELLED: Pruritus is a common complication of cholestatic liver diseases or liver graft dysfunction. Current medical therapies lack efficacy. The molecular adsorbent recirculating system (MARS) represents an interesting therapeutic option. Our objective was to report our experience in the management of four patients with intractable pruritus with MARS. PATIENTS AND METHODS: The MARS treatment cycle included three consecutive treatments, each of 8 hours duration. The four patients with intractable pruritus who were treated had primary biliary cirrhosis/autoimmune hepatitis overlap syndrome (n = 1), ductopenic allograft rejection (n = 2), or posttransplant cholestatic HCV recurrence (n = 1). Intensity of pruritus was documented 24 hours before as well as 24 hours, 7 and 30 days after MARS therapy, and at the end of follow-up. We measured complete blood cell counts, glucose, BUN, creatinine, sodium, potassium, AST, ALT, GGT, alkaline phosphatase, bilirubin, prothrombin activity, and activated partial thromboplastin time. RESULTS: MARS therapy was well tolerated. Patient 1 experienced temporal relief of pruritus, but needed another MARS cycle because of relapse. Patient 2 experienced partial and temporary relief of pruritus, was listed for retransplantation, and received a liver graft 2 months later. Patient 3 showed a dramatic reduction in the degree of pruritus with MARS. Pruritus in patient 4 decreased promptly with MARS therapy and conversion of immunosuppression to tacrolimus, thereby avoiding retransplantation. CONCLUSION: MARS therapy is a promising, safe therapeutic option to treat refractory pruritus caused by cholestatic liver disorders.

Efficacy of lactic acid against Listeria monocytogenes attached to poultry skin during refrigerated storage.

AIMS: The aim of this study was to evaluate the effect of lactic acid washing on the growth of Listeria monocytogenes on poultry legs stored at 4 degrees C for 7 days. METHODS AND RESULTS: Fresh inoculated chicken legs were dipped into either a 0.11, 0.22 mol l(-1) or 0.55 mol l(-1) lactic acid solution for 5 min or distilled water (control). Surface pH values, sensorial characteristics and L. monocytogenes, mesophiles and pychrotrophs counts were evaluated after treatment (day 0) and after 1, 3, 5 and 7 days of storage at 4 degrees C. Legs washed with 0.55 mol l(-1) lactic acid for 5 min showed a significant (P < 0.05) inhibitory effect on L. monocytogenes compared with control legs, being about 1.74 log units lower in the first ones than in control legs after 7 days of storage. Sensory quality was not adversely affected by lactic acid, with the exception of colour. CONCLUSIONS: Treatments with 0.55 mol l(-1) lactic acid reduced bacterial growth and preserved reasonable sensorial quality after storage at 4 degrees C for 7 days. However, it was observed a reduction in the colour score within 1 day post-treatment with 0.55 mol l(-1) lactic. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates that, while lactic acid did reduce populations of L. monocytogenes on poultry, it did not completely inactivate the pathogen. The application of lactic acid may be used as an additional hurdle contributing to extend the shelf-life of raw poultry.

[Cardiac troponin I determination in patients with chronic renal failure]. / Determinación de troponina I cardiáca en pacientes con insuficiencia renal crónica.

OBJECTIVE: The aim of the study was evaluate cardiac troponin I (cTnI) determination in patients with chronic renal failure (CRF) and compare with creatine kinase-MB isoenzyme (CK-MB and CK-MB/CK). METHODS: We performed a retrospective study on patients with CRF with MDRD (modification of diet in renal disease study group) < 60 mL/min admitted with suspected myocardial injury by history, physical examination and electrocardiography. cTnI measurement was assessed at admission with the ACCESS analyzer (Beckman). RESULTS: Acute myocardial injury (AMI) was diagnosed in 10% (47/467) patients with cTnI determination > 0.05 ng/mL, while the diagnostic was angina in 9% (41/467) and in 81% (379/467) we finded other diagnostics. In the AMI group, 49% had chest discomfort, 43% diabetes and the mortality was 45%, while in the angina group were 41%, 32% and 7%, respectively. The sensitivity for cTnI with cut-off value > 0.5 ng/mL was 70% and specificity 92%. The number of false positives was 31% (20 patients). DISCUSSION: cTnI is the preferred biomarker for myocardial damage in patients with CRF. Other cut-off value could enhance the sensitivity for AMI.

A comparison of the methods used to determine chewing preference.

For much human activity there exists a 'lateral preference', that is a tendency to use one side of the body or the other; with respect to the hands for example, the vast majority of individuals have a preference for either the right or left hand. Most experts agree that mastication is no exception in that there is a 'preferred chewing side' but the determination of this preference is somewhat complex. This research analyses the mastication of 60 healthy subjects by means of preferred chewing side or 'PCS' tests, the Kazazoglu test, and kinesiography (KGF). While some authors consider the PCS to be the side which first comes into contact with the food we prefer to define it as the side on which the majority of the cycles analysed and registered take place. The objective of this research was to analyse the relationship that might exist between the two different methods used for determining a lateral chewing preference. Although there was no statistically significant agreement between the two techniques, both reflected the fact that there was a marked preference for the right hand side.

Sulindac in familial adenomatous polyposis: evaluation by nuclear morphometry.

OBJECTIVE: To find out if nuclear morphometry is a useful indicator of prognosis in patients with familial adenomatous polyposis (FAP) before and after treatment with sulindac. DESIGN: Open study. SETTING: Teaching hospital, Spain. SUBJECTS: 29 patients (17 women and 12 men) with FAP who had been treated by colectomy. There were two control groups: 17 people with healthy rectal mucosa and 10 patients with colorectal cancer. INTERVENTIONS: The 29 patients with FAP were treated with sulindac 150 mg orally twice daily for 6 months. MAIN OUTCOME MEASURES: Results of histological examination of biopsy specimens and nuclear morphometry. RESULTS: Before treatment, all patients with FAP had nuclei of cells in the rectal mucosa that were intermediate in size between those in healthy mucosa (small nuclei) and those in cancer (large nuclei). After 6 months' treatment with sulindac the patients with FAP no longer had any polyps and the size of the nuclei was similar to those in healthy mucosa. Only 1 patient failed to respond, and in this patient one of the polyps subsequently became malignant. CONCLUSIONS: Nuclear morphometry may be useful in identifying patients with FAP who are at high risk of malignant degeneration.

[Mid-term results of percutaneous closure of atrial septal defect in children]. / Resultados a medio plazo del cierre percutáneo de la comunicación interauricular en niños.

OBJECTIVE: To evaluate the medium-term results of percutaneous closure of atrial septal defect. METHODS: Twenty-two children (mean weight, 23 11kg; mean age, 5.7 2.4 years) underwent percutaneous atrial septal defect closure under general anesthesia. The procedure was monitored by transesophageal echocardiography. DAS-Angel Wings (n4) and the Amplatzer device (n18) were used. RESULTS: Mean pulmonary artery pressure was 13 2.8mmHg, mean pulmonary vascular resistance was 1.50.5U/m2 and mean Qp/Qs flow ratio was 2.2 0.6. The mean diameter of the defects was 14.5 6.3mm by transesophageal echocardiography OmniPlane measurement and 15.95.3mm using balloon occlusion reference. A total of 31 devices were used: 4 Angel Wings and 27Amplatzer devices. Twelve Amplatzer devices were withdrawn through the introducer without complications, 5 due to a discrepancy in the size of the left auricle, 4 because they were too small to stabilize in the septum and 3 due to defective opening in the left auricle. In 19 patients implantation was successful. In 17 patients transthoracic color Doppler echocardiography carried out 24 hours after the procedure showed a minimal shunt which was no longer present 1 month later. The mean time of discharge was 38 12 hours after the procedure. After a mean follow up 15 6 months the patients remain asymptomatic with no clinical or technical problems. CONCLUSION: The success rate of percutaneous closure of atrial septal defects in well-selected patients was high and presented no complications.

[Predictors of sudden death in coronary artery disease]. / Predictores de muerte súbita en la enfermedad coronaria.

Although advances in the management of acute myocardial infarction have resulted in a decline in long-term risk of sudden death, it continues to be high in certain subsets of patients. Thus, it is important to identify and treat these patients. Left ventricular ejection fraction less than 0.40, frequent premature ventricular ectopy on Holter monitoring, late potentials on signal-averaged electrocardiogram, impaired heart rate variability, abnormal baroreflex sensitivity and inducible sustained monomorphic ventricular tachycardia during electrophysiological study are predictors of sudden death and arrhythmic events. Although the negative predictive value of each factor is high, the positive predictive accuracy is low. Several tests can be combined to obtain higher positive predictive values. In fact, in some studies combined noninvasive tests have been used to select patients for ventricular stimulation study. Some preventive treatment can be applied in these patients. Available data do not justify prophylactic therapy with amiodarone in high-risk survivors of acute myocardial infarction. Sudden death and total mortality have been significantly reduced in postinfarction patients by long-term beta blockade. Hence, beta blockers should be given to all patients with acute myocardial infarction who do not have contraindications to their use. The MADIT study has shown the beneficial effect of implantable cardioverter defibrillator in reducing mortality in patients with prior myocardial infarction, an ejection fraction less than 0.36, asymptomatic nonsustained ventricular tachycardia, and inducible sustained ventricular tachycardia, unsuppressable by procainamide. Besides, several studies are under way to evaluate the prophylactic use of implantable defibrillator for improving survival in high-risk patients.

Investigation of risk factors for porcine Taenia solium cysticercosis: a multiple regression analysis of a cross-sectional study in the Yucatan Peninsula, Mexico.

A cross-sectional survey for seropositivity to cysticercosis of pigs in the Yucatan Peninsula, Mexico, was carried out in 1996 together with a standardized questionnaire on predetermined individual pig and household risk factors for porcine infection. Serum samples from 697 pigs were analysed by immunoblot for antibodies to Taenia solium cysticercosis and questionnaires from 227 households in 18 villages were collected. All the data were analysed using multivariate analytical techniques taking household clustering into account. The overall porcine seroprevalence in the area was found to be 29%. The most important risk factors for seropositivity in pigs were presence versus absence of a toilet (adjusted odds ratio [adj. OR] 2.37, P = 0.005), crowded households (adj. OR 1.75, P = 0.034) and both corralling (adj. OR 2.14, P = 0.017) and letting pigs loose (adj. OR 2.32, P = 0.035) versus tying them up. There was evidence of clustering at household level and that possible risk factors at municipal or village level may also interact with higher risk management practices such as allowing pigs to run loose.

[Prognostic value of optic morphometry in colorectal cancer]. / Valor pronóstico de la morfometría óptica en el cáncer colorrectal.

UNLABELLED: In many types of cancer, certain morphometric characteristic of tumor cells correlate with patient survival. Our observations suggested that the survival of patients with colorectal carcinomas is negatively correlated with tumor-cell nucleus size. METHODS: We investigated relationships between postsurgery survival and nucleus morphometric in 90 patients who had undergone resection for a colorectal tumor. The nucleus-size variables considered were maximum diameter, minimum diameter, perimeter, area, and form factor (means for 100 nuclei from each patient were used in all cases). RESULTS: Our results confirmed that patients with large maximum nucleus diameter (where large = greater than the first quartile) have significantly worse survival than patients with smaller maximum nucleus diameter (mean survival, 28 vs. 43 months). Similar results were obtained for the other nucleus-size variables. Stepwise Cox regression analysis was then performed, with postsurgery survival time as the dependent variable and the following candidate independent variables: age, gender. Dukes class, degree of histologic differentiation, the various nucleus-size variables, and relative frequencies of different nucleus shapes (spherical, oval, cylindrical, fusiform, and irregular). The variables selected for the prognostic model were Dukes class, relative frequency of irregular nuclei, and maximum nucleus diameter. CONCLUSIONS: These findings indicated that nucleus size and shape are useful predictors of survival. Even in Dukes class is known, consideration of nucleus size and shape significantly improves prediction of survival.

[Reliability of digital coronary quantification in a hemodynamic laboratory. Comparison with a film-based system]. / Fiabilidad de la cuantificación coronaria digital realizada en el laboratorio de hemodinámica. Comparación con un sistema basado en película.

BACKGROUND AND OBJECTIVES: Quantitative coronary angiography can be performed in two ways: on-line during catheterism, and off-line once the procedure is finished. Consequently, several studies have been published comparing both systems. Nevertheless, none of them has compared the measurements made off-line with those acquired on-line by the hemodynamist in charge of procedure. The objective of this study was to compare the measurements made on-line by the hemodynamist involved in the procedure with a digital system (DCI) with those obtained off-line by an independent and alien observer to the procedure by using film-based system (CMS). MATERIAL AND METHODS: Forty coronary lesions suitable for quantification were measured in a prospective fashion. They came from follow-up angiograms. Either balloon or stent were used in the previous angioplasty. Stenoses were assessed on-line and off-line by using the most severe view as judged by the hemodynamist. RESULTS: No significant differences were found for obstruction diameter, reference diameter nor percent diameter stenosis. Pearson's correlation coefficient values (r), intraclass correlation coefficient (ri), regression line equation and mean of signed differences with their standard deviations are showed: a) obstruction diameter: r = 0.83, ri = 0.83, DCI = 0.42 + 0.76 x CMS, -0.01 +/- 0.42 mm; b) reference diameter: r = 0.72, ri = 0.69, DCI = 1.29 + 0.61 x CMS, 0.003 +/- 0.38 mm, y c) percent diameter stenosis: r = 0.86, ri = 0.86, DCI = 10.05 + 0.77 x CMS, 1.19 +/- 10.75%. CONCLUSIONS: We attained good concordance between both quantification systems under clinical conditions. In our opinion these results support the use of on-line quantification as a reliable tool for clinical decision making in the catheterization laboratory.

[The importance of thrombin and its inhibition in unstable angina. Nonfractionated heparin, hirudin and defractionated heparins]. / Importancia de la trombina y su inhibición en la angina inestable. Heparina no fraccionada, hirudinas y heparinas fraccionadas.

Atheroma plaque rupture with liberation of tissue factor activates the coagulation cascade and plateletes, leading to the formation of intracoronary thrombi in many patients with acute coronary syndromes. In this process, tissue factor, thrombin, Factor Xa and fibrin play a major role. This review analyses the clinical efficacy of the antithrombotic drugs: fractionated heparin, low molecular or fractionated heparins, direct thrombin inhibitors, specific Xa factor inhibitors and inhibitors of the tissue factor pathway in patients with unstable angina and non-Q wave myocardial infarction. Enoxaparin, a low molecular weight fractionated heparin, has shown to be associated with a greater clinical efficacy, superior to that achieved with conventional heparin anticoagulation or treatment with aspirin, and probably should be considered as the antithrombotic of choice. Present clinical research should be aimed at the identification of patients with greater benefit, new treatment protocols with other antithrombotic drugs and the efficacy in special situations such as invasive coronary interventions or the association with other drug like, thrombolytic agents or new antiplatelet antiaggregants.

Prognostic value of nuclear morphometry in colorectal cancer.

PURPOSE: In many types of cancer, certain morphometric characteristic of tumor cells correlate with patient survival. Our observations suggested that the survival of patients with colorectal carcinomas is negatively correlated with tumor-cell nucleus size. METHODS: We investigated relationships between postsurgery survival and nucleus morphometrics in 90 patients who had undergone resection for a colorectal tumor. The nucleus-size variables considered were maximum diameter, minimum diameter, perimeter, area, and form factor (means for 100 nuclei from each patient were used in all cases). RESULTS: Our results confirmed that patients with large maximum nucleus diameter (where large = greater than the first quartile) have significantly worse survival than patients with smaller maximum nucleus diameter (mean survival, 28 vs. 43 months). Similar results were obtained for the other nucleus-size variables. Stepwise Cox regression analysis was then performed, with postsurgery survival time as the dependent variable and the following candidate independent variables: age, gender, Dukes class, degree of histologic differentiation, the various nucleus-size variables, and relative frequencies of different nucleus shapes (spherical, oval, cylindrical, fusiform, and irregular). The variables selected for the prognostic model were Dukes class, relative frequency of irregular nuclei, and maximum nucleus diameter. CONCLUSIONS: These findings indicated that nucleus size and shape are useful predictors of survival. Even if Dukes class is known, consideration of nucleus size and shape significantly improves prediction of survival.

Application of an immunoassay to determine risk factors associated with porcine cysticercosis in rural areas of Yucatan, Mexico.

A Western blot assay for identification of 26 kDa and/or 8 kDa antigens in a crude saline extract (CSE) of Taenia solium metacestodes, previously developed for human cysticercosis, was evaluated for use with pigs. The test population used for assay standardisation consisted of 45 cysticercotic pigs (5 pigs positive by necropsy and 40 selected by tongue palpation and LL-Gp immunoblot but not confirmed by necropsy), 48 pigs with heterologous infections and 40 negative controls from endemic and non-endemic areas. The test detected 93% of the cysticercotic group and was 100% specific. In a field study this antigen preparation was compared by immunoblot with antibody recognition for Gp13-50 antigens in a lentil-lectin semi-purified glycoprotein extract of T. solium (LL-Gp). The seroprevalence to CSE antigen was slightly lower (26/75) when compared to LL-Gp (29/75) and this represented a non-significant difference. The CSE Western blot assay was used to assess seroprevalence of T. solium cysticercosis in pig populations in the state of Yucatan, Mexico. A total of 1099 pigs sampled at random from 25 villages revealed a seroprevalence of 23% (253/1099). Seroprevalence in intensively reared, farmed pigs was 2% (7/228). In comparison with farmed pigs, the seroprevalence was 33% (172/513) in free-roaming backyard pigs (OR=13.86, CI=4.0747.22, p<10(-6)) and 25% (74/98) in semi-confined backyard pigs (OR=14.03, CI=5.60-35.16, p<10(-6)). There was no significant difference in seroprevalence by sex (p=0.23). Seroprevalence decreased with age (chi(2)-test for linear trend=7.803, p<0.006). Results of this study demonstrate that the CSE Western blot can be applied for reliable immunodiagnosis of T. solium cysticercosis in pigs. Furthermore, variation in pig husbandry in Yucatan indicated significantly higher exposure to cysticercosis in free-roaming backyard pigs compared to intensively reared animals from the same area.

Bovine babesiosis in dual purpose calves in the state of Yucatan, Mexico.

Thirty-eight dual purpose calves in the 3 agricultural zones of the state of Yucatan, Mexico were monitored for antibodies to Babesia bovis and B. bigemina from close to birth up to 12 months of age. The results showed that infection with both parasites is widespread throughout the 3 zones. Many of the animals had produced antibody to both parasites by 6 months of age indicating high transmission rates resulting in enzootic stability for both parasites. Any changes to agricultural practices in the state that could affect disease stability through either reduction in numbers of tick vectors or the introduction of susceptible adults will have to be accompanied with measures such as vaccination to limit losses due to clinical babesiosis.

[Radiofrequency catheter ablation for atrial tachycardia]. / Ablación con catéter mediante radiofrecuencia de taquicardias auriculares.

INTRODUCTION: Radiofrequency catheter ablation of atrial tachycardia guided by bipolar activation mapping has been reported in the last years. This article reports the use of radiofrequency catheter ablation for the treatment of atrial tachycardia using simultaneous bipolar and unipolar activation mapping at our institution. METHODS: Nine patients (7 male and 2 female, mean age 37.2 +/- 24.1 years), were selected for radiofrequency catheter ablation of drug refractory atrial tachycardia. Mapping procedure included an investigation of the local earliest bipolar and unipolar activity and unipolar morphology analysis. RESULTS: Atrial tachycardia was successfully ablated in 7 patients (78%) with an average number of 6.8 +/- 3.1 RF pulses. Procedure related complications and tachycardia follow-up recurrences were not observed in any patient. Bipolar local activation time was significantly shorter at successful than at unsuccessful ablation sites (-30 +/- 21.1 ms vs -18.3 +/- 20.6 ms; p = 0.01). No difference was observed in unipolar local activation time between successful and unsuccessful sites (-22.5 +/- 26.2 ms vs -19.8 +/- 21.5 ms; p = 0.56). Accurate localization of the successful ablation site by unipolar electrogram analysis was not feasible because a "QS" pattern was found at both 21 unsuccessful and 2 successful ablation sites. Finally, a fast slope of the negative deflection of the unipolar electrogram was found at 2 out of 45 unsuccessful and 3 out of 6 successful ablation sites. CONCLUSIONS: Radiofrequency catheter ablation of atrial tachycardia is feasible without complications in most patients. Bipolar activation mapping accurately localizes the successful ablation site. A "QS" pattern is not predictive of successful radiofrequency application.

[Treatment of acute myocardial infarction with rt-PA in 60 minutes. Cooperative study]. / Tratamiento del infarto agudo del miocardio con rt-PA en 60 minutos. Estudio cooperativo.

UNLABELLED: Thrombolytic therapy (TT) modifies the natural history of acute myocardial infarction (AMI) diminishing morbi-mortality rate. In recent studies, modification of infusion velocity, decreased the mortality 10 percentage points. OBJECTIVE: Test if rt PA administration over an hour is safe and practical. MATERIAL AND METHODS: A prospective, cooperative trial during 3 years, included patients with AMI with less than 6 hours of the onset of symptoms that received rt-PA therapy. Initially 10 mg bolus and then 90 mg over 60 minutes period. Together with the administration of rt-PA, 5000 units of heparin was given, followed by 1000 units per hour adjusted to keep PTT at 1.5 to 2 times normal. All patients received aspirin and according of the evolution adjuvant therapy. We defined bleeding complications and/or cerebrovascular accident related to thrombolytic therapy. RESULTS: We included 225 patients who received rt-PA. Average age was 57.1 +/- 22.2 years, 78.7% males and 21.3% females. Arrival time at hospital was 2.93 +/- 1.7 hours. 82.2% were in class I-II by NYHA. 59.2% had anterior wall location and 32.4% posterior-inferior wall 80% had reperfusion criteria. Only 7.1% required transfusion and 0.4% presented CNS bleeding. The survival rate was 95.2%. The mortality had no relation with bleeding. CONCLUSION: Fast infusion is an effective and safe method. Transfusion requirements are no greater, and CNS bleeding was noted in 0.4% of the cases.