Acutely applied MDMA enhances long-term potentiation in rat hippocampus involving D1/D5 and 5-HT2 receptors through a polysynaptic mechanism.

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is a drug of abuse that induces learning and memory deficit. However, there are no experimental data that correlate the behavioral evidence with models of synaptic plasticity such as long-term potentiation (LTP) or long-term depression (LTD). Using field potential recordings in rat hippocampal slices of young rats, we found that acute application of MDMA enhances LTP in CA3-CA1 synapses without affecting LTD. Using specific antagonists and paired-pulse facilitation protocols we observed that the MDMA-dependent increase of LTP involves presynaptic 5-HT2 serotonin receptors and postsynaptic D1/D5 dopamine receptors. In addition, the inhibition of PKA suppresses the MDMA-dependent increase in LTP, suggesting that dopamine receptor agonism activates cAMP-dependent intracellular pathways. We propose that MDMA exerts its LTP-altering effect involving a polysynaptic interaction between serotonergic and dopaminergic systems in hippocampal synapses. Our results are compatible with the view that the alterations in hippocampal LTP could be responsible for MDMA-dependent cognitive deficits observed in humans and animals.

Prevalencia de Enterococos resistentes a antibióticos en aguas servidas en el norte de Chile / Prevalence of antibiotic resistant Enterococcus spp in waste waters in the north of Chile

Background: There is little information available in Chile on the distribution of Enterococcus spp in waste water and its implications in transmission of antibiotic resistance through the water cycle. Enterococcus spp are common in nosocomial infections and may spread antibiotic resistance through the food chain. Aim: To determine the presence of antibiotic resistant Enterococcus spp in the sewage of Antofagasta, Chile. Material and Methods: Samples of sewage from two sewage treatment plants and from the Public Hospital of Antofagasta collector were obtained. Enterococcus spp were isolated on m-Enterococcus agar containing ampicillin, vancomycin and streptomycin. The isolates were identified and subjected to biochemical typing (PhPlate). Minimal inhibitory concentration determination was performed by agar dilution technique. Results: High counts of resistant Enterococcus spp were found on the streptomycin plates, lower on ampicillin and very low on vancomycin plates. A total of 63 Enterococcus spp strains were typed and the identification showed 5 different species; E faecalis (65%), E faecium (14%), E hirae (13%), E durans (6%) and E gallinarum (2%). The typing revealed a high diversity among the isolates. Two biochemical phenotypes were predominant, C1 (21 strains) and C6 (7 strains). Both were highly resistant to gentamycin and streptomycin; moderately resistant to ampicillin, cloramphenicol, tetracycline and ciprofloxacin, and with intermediate susceptibility to vancomycin. Both phenotypes were found in the sewage of the hospital collector and in the treatment plants. Conclusions: In the sewage of Antofagasta we found dominating phenotypes of multiresistant Enterococcus spp. Sewage could be an important way of transmission of these microorganisms.

Utilidad del ecocardiograma y de marcadores séricos en la estratificación de riesgo en pacientes cursando con embolia pulmonar submasiva / Utility of echocardiogram and serum markers in the risk stratification in patients attending with submassive pulmonary embolism

Los pacientes que cursan tromboembolismo, dependiendo de su severidad, pueden recibir variados tratamientos no exentos de efectos adversos. Existe, por lo tanto, la necesidad de estratificar riesgo -magnitud- mortalidad con criterios que le permitan al clínico tomar las mejores decisiones. En este artículo se pretende establecer un sistema de aproximación al tromboembolismo pulmonar de acuerdo a la información hasta ahora disponible.

[Mechanical fragmentation and intrapulmonary fibrinolysis in the treatment of massive pulmonary embolism hemodynamic repercussions]. / Fragmentación mecánica y fibrinólisis intrapulmonar en el tratamiento del tromboembolismo pulmonar masivo con repercusión hemodinámica.

OBJECTIVE: To evaluate the efficacy and safety of mechanical fragmentation associated with intrapulmonary thrombolysis to treat massive pulmonary thromboembolism (PTE) with altered hemodynamics. MATERIAL AND METHOD: Fifty-one patients with a diagnosis of acute PTE were enrolled, the criteria being a Miller index over 0.50 and mean pressure of 30 mmHg in the principal superior pulmonary artery. The initial clinical pictures included shock (19 patients), syncope (6) and severe dyspnea at rest (26). Oxygen saturation measured by pulse oxymetry was 71.4%. Mean pulmonary artery pressure was 46.1 mmHg. The main thromboembolisms were fragmented, with one bolus of a fibrinolytic agent administered during the fragmentation procedure. An infusion of the fibrinolytic agent was administered through a catheter. Monitoring included clinical assessment, pulmonary scintigraphy and echocardiography. RESULTS: After fragmentation and administration of the bolus dose of the fibrinolytic agent, improvement was observed in 49 patients (97.2%). Mean pressure after mechanical and pharmacological treatment was 24.1 mmHg. Technical success was achieved in 100% of the patients. CONCLUSION: The results attest to the efficacy and safety of mechanical fragmentation and medical thrombolysis in treating massive PTE affecting hemodynamics, leading to clinical improvement and lowered pulmonary artery pressure.

Fragmentación mecánica y fibrinólisis intrapulmonar en el tratamiento del tromboembolismo pulmonar masivo con repercusión hemodinámica / Mechanical fragmentation and intrapulmonary fibrinolysis in the treatment of massive pulmonary embolism hemodynamic repercussions

Objetivos: Evaluar la eficacia y seguridad de la fragmentación mecánica asociada a trombólisis intrapulmonar en el tromboembolismo pulmonar (TEP) masivo con alteración hemodinámica. Material y método: Un total de 51 pacientes diagnosticados de TEP masivo con repercusión hemodinámica. Se incluyeron bajo este epígrafe pacientes con TEP agudo con un índice de Miller superior a 0,50 y una presión medida en la arteria pulmonar principal superior 30 mmHg. Cuadro clínico de inicio: 19 shock, 6 síncope y 26 disnea intensa de reposo. La saturación de O2 medida por pulsioximetría: 71,4 por ciento. Presión media en arteria pulmonar: 46,1 mmHg. Se realizó fragmentación de los tromboémbolos más importantes. Durante la fragmentación se administró un bolo de fibrinolítico. A través del catéter se administró infusión de fibrinolítico. El seguimiento se realizó con valoración clínica, gammagráfica pulmonar y ecocardiográfica. Resultados: Tras la fragmentación y administración del bolo de trombolítico se observó mejoría clínica en 49 pacientes (97,2 por ciento). La presión media postratamiento mecánico y farmacológico fue de 24,1 mmHg. Éxito técnico del 100 por ciento. Conclusión: Los datos aportados avalan la eficacia y seguridad de la fragmentación mecánica y trombólisis farmacológica en el tratamiento del TEP masivo con afectación hemodinámica, mejorando la sintomatología y disminuyendo la presión arterial pulmonar (AU)

Massive pulmonary embolism: treatment with the hydrolyser thrombectomy catheter.

PURPOSE: To assess the efficacy of clot removal with use of the Hydrolyser thrombectomy catheter in acute massive pulmonary embolism (PE). MATERIALS AND METHODS: Eleven patients (eight women, three men) with a mean age of 61 (range, 37-79) years with acute massive PE underwent percutaneous mechanical thrombectomy (PMT) with use of the Hydrolyser. In four patients with no contraindication, fibrinolysis was performed with use of urokinase at low doses after thrombectomy. RESULTS: Ten patients (90.91%) recovered from massive PE and were discharged within 11 days. The Urokinase Pulmonary Embolism Trial angiographic severity indexes (mean +/- SD) were 14.7 +/- 2.6 and 7.5 +/- 2.7, respectively, before and after thrombectomy (P < .001). Partial arterial pressures of O2 increased from 72.8 mm Hg +/- 16.4 to 93.5 mm Hg +/- 5.6 (P < .005). Pulmonary artery pressure decreased from 45.5 mm Hg +/- 14.2 to 29.5 mm Hg +/- 13.6 after thrombectomy (P < .0001). Calculated by semiquantitative computed analysis, PMT with use of the Hydrolyser removed 74.06% of thrombus +/- 13.46%. One patient developed self-limited hemoptysis immediately after thrombectomy. One patient died during the procedure secondary to PE. CONCLUSION: PMT with use of the Hydrolyser is effective and safe in massive PE, resulting in improved hemodynamics and blood oxygenation and decreased pulmonary artery pressure. It offers an alternative to fibrinolysis and surgical thrombectomy.

[Colorectal neoplasms. Treatment of obstruction with autoexpanding metal stents]. / Neoplasia colorrectal. Tratamiento de la obstrucción con endoprótesis metálicas autoexpandibles.

BACKGROUND: Expandable metal stents can be used as a palliative or pre surgical method to decompress obstructing colonic carcinomas. AIM: To assess the effectiveness of these stents in the treatment of obstructive colonic carcinoma. PATIENTS AND METHODS: Expandable metal stents were placed in nine patients with the diagnosis of colorectal carcinoma and with clinical and radiographic signs of intestinal obstruction. Stents were placed under fluoroscopic guidance in nine patients and with endoscopic help in 2. The indications were palliative treatment in 7 and pre surgical decompression in 2 patients. RESULTS: Stent placement was successful in all patients. One patient presented a self limited rectal bleeding after the procedure. Obstruction was relieved in less than 24 hours after the procedure. CONCLUSION: Expandable metal stent placement is an effective means of relieving intestinal obstruction caused by colorectal carcinoma.

External iliac vein thrombosis after renal transplantation: treatment by thrombolysis and stent placement: a case report.

We present a patient with iliac vein stenosis and thrombosis, which occurred 2 weeks after renal transplantation and were secondary to a perivascular hematic collection. The vein stenosis was identified by color Doppler ultrasonography and venography. Computed tomography demonstrated a perivascular collection. One week later, control venography identified iliac vein thrombosis. The patient underwent pharmacological thrombolysis with local infusion of urokinase for 4 hr, percutaneous transluminal angioplasty, and percutaneous installation of a metallic stent (Wallstent), with immediate favorable results. The patient remains in stable condition at 2 years after the procedure.

Mechanical fragmentation and pharmacologic thrombolysis in massive pulmonary embolism.

PURPOSE: To evaluate the usefulness of mechanical fragmentation associated with intrapulmonary thrombolysis in acute massive pulmonary embolism (PE). PATIENTS AND METHODS: Sixteen cases of massive PE treated with mechanical fragmentation associated with pharmacologic thrombolysis were retrospectively studied. Severity of PE was assessed with the angiographic index according to the Urokinase Pulmonary Embolism Trial (maximum value of 18; score according to whether obstruction was central or peripheral, complete or partial). Mechanical fragmentation of the emboli was performed with angiographic catheters and angioplasty balloons. Urokinase was infused directly into the thrombus during the course of 8-24 hours. The effect of therapy was measured with direct pulmonary artery pressure (PAP) and blood O2 values. RESULTS: Pre- and postinfusion angiographic index mean values (+/- standard deviation) were 13.7 +/- 1.4 and 6.1 +/- 2.2 (P < .0001). Mean pre- and postinfusion PAPs were 48.2 +/- 13.4 and 18.5 +/- 7.2 mm Hg (P < .0001). PaO2 increased from 60.1 +/- 12.1 to 88.7 +/- 23.4 mm Hg (P = .01). Fourteen patients (87.5%) completely recovered. One patient died during treatment despite improvement in PAP and PaO2 parameters. There were no major hemorrhagic complications. CONCLUSIONS: The data support the efficacy of mechanical fragmentation associated with pharmacologic thrombolysis in the treatment of acute massive PE, resulting in improved hemodynamics and-blood oxygenation and in decreased PAP, with low morbidity.

[Percutaneous biliary endoprostheses. Clinical experience of 6 years]. / Endoprótesis biliar percutánea. Experiencia clínica de 6 años.

The aim of this study was to assess the effectiveness and long term permeability of percutaneous biliary endoprostheses. Seventy three patients with biliary tract obstruction due to a primary malignant tumor (n = 60), lymph node metastases at the porta hepatis (n = 10) and benign stenosis of a biliary-enteric anastomosis (n = 3), were treated between 1985 and 1990. Plastic prostheses were installed in 63 patients and metallic in 10. The procedure had a 30% incidence of complications. Thirty three percent of the prostheses remained patent until patient's death. In 15 and 40% of patients, signs of prosthesis obstruction were observed three and six months after installation respectively, bearing in mind a mean survival of 24 weeks. In 90% of patients there was a clinical and laboratory improvement. Mortality was 30% at 30 days in the group of patients with malignant diseases. It is concluded that the installation of percutaneous biliary endoprostheses is a relatively safe and well tolerated procedure, with a low incidence of complications or mortality and that allows an effective biliary decompression.

[Syncope: recurrence and prognosis during 2 years]. / Síncope: recurrencia y pronóstico a dos años.

We followed up 143 patients that had been admitted to intensive care units of a general hospital with syncope. 127 patients (89%) remained in follow up for a mean of 24 months (range 3 to 54 months). There were 70 men and 57 women and the mean age was 71.5 years. Recurrences were observed in 21 patients (17%) and were similar for patients whose syncope had a cardiovascular origin (10%), non cardiovascular origin (25%) or an undetermined cause (18%). Mortality from cardiac or vascular causes was 20% in the cardiovascular origin group, and 5 and 4.2% in the other groups, respectively (p less than 0.005). Recurrence did not influence mortality. A history of hypertension, cerebrovascular accidents and ventricular arrhythmias was associated to higher mortality risk (p less than 0.05).

[Syncope: general characteristics and its relation to age]. / Síncope: características generales y relación con la edad.

We retrospectively analyzed the clinical data of 146 patients admitted to a general hospital with the diagnosis of syncope. A definite or highly likely cause was identified in 91 patients (62%). These were of cardiovascular origin in 78%: conduction defects (31), sinus node disease (9), obstructive causes (8), ventricular arrhythmia (8), ischemia (5) and miscellaneous (14). A non cardiovascular origin was present in 22% of patients: intoxication (7), hysteria (5), hypoxemia (3), vasovagal (2), gastrointestinal bleeding (2) and 2 others. The final diagnosis in patients with a known cause was established by the history and physical examination in 16, the ECG in 42, Holter 9, ECG monitoring in ICU 8 and echocardiogram 6. No difference in the distribution of causes was present between patients below or above 65 years of age. In hospital mortality was 2%.

Hipertensão renovascular. Apresentação de três casos / Renovascular hypertension. Report of 3 cases

Os autores relatam tres casos de portadores de hipertensao renovascular estudados por metodos invasivos e nao invasivos e submetidos a intervencao cirurgica corretiva com excelentes resultados