Near-infrared spectroscopy (NIRS) could be a useful continuous, non-invasive technique for monitoring the effect of partial pressure of carbon dioxide (PaCO2) fluctuations in the cerebral circulation during ventilation. The aim of this study was to examine the efficacy of NIRS to detect acute changes in cerebral blood flow following PaCO2 fluctuations after confirming the autoregulation physiology in piglets. Fourteen piglets (<72 h of life) were studied. Mean arterial blood pressure, oxygen saturation, pH, glycemia, hemoglobin, electrolytes, and temperature were monitored. Eight animals were used to evaluate brain autoregulation, assessing superior cava vein Doppler as a proxy of cerebral blood flow changing mean arterial blood pressure. Another 6 animals were used to assess hypercapnia generated by decreasing ventilatory settings and complementary CO2 through the ventilator circuit and hypocapnia due to increasing ventilatory settings. Cerebral blood flow was determined by jugular vein blood flow by Doppler and continuously monitored with NIRS. A decrease in PaCO2 was observed after hyperventilation (47.6±2.4 to 29.0±4.9 mmHg). An increase in PaCO2 was observed after hypoventilation (48.5±5.5 to 90.4±25.1 mmHg). A decrease in cerebral blood flow after hyperventilation (21.8±10.4 to 15.1±11.0 mL/min) and an increase after hypoventilation (23.4±8.4 to 38.3±10.5 mL/min) were detected by Doppler ultrasound. A significant correlation was found between cerebral oxygenation and Doppler-derived parameters of blood flow and PaCO2. Although cerebral NIRS monitoring is mainly used to detect changes in regional brain oxygenation, modifications in cerebral blood flow following experimental PaCO2 changes were detected in newborn piglets when no other important variables were modified.

Background: Transmitted drug resistance (TDR) occurs in patients with HIV infection who are not exposed to antiretroviral drugs but who are infected with a virus with mutations associated with resistance. Aim: To determine the prevalence of TDR and characterize HIV reverse transcriptase and protease mutation patterns. Material and Methods: HIV infected antiretroviral treatment-naive patients treated in three centers between 2014 and 2018 were studied. A genotyping study was carried out. The HIVdb Program (Stanford University) and the World Health Organization (WHO) TDR surveillance mutation list were used to register resistance-associated mutations. Results: We enrolled 220 patients aged a median of 29 (interquartile range (IQR) 24-34) years, 99% men. Median CD4 count was 365 cells/μL (IQR 250-499 cells/μL) and median viral load was 39.150 copies/mL (IQR 9,270 −120,000). The overall prevalence of RTD was 10.45% (95% CI 6.7-15.2, N = 23/220). The higher frequency of TDR was against non-nucleoside reverse transcriptase inhibitors, reaching 9.0% (95% CI 5.6-13.6), followed by nucleoside reverse transcriptase inhibitors reaching 1.8% (95% CI 0.49-4.5) and protease inhibitors reaching 0.45% (95% CI 0.01-2.5). The mutations in reverse transcriptase were M41L, L210W, D67N, K70E, M184V, K103N (6.36%, 95% CI 3.5-10.4), G190A, E138A, K101E, and I84V in protease. Conclusions: These results should prompt a change in recommendations for starting antiretoviral therapy, especially in first-line regimens that include non-nucleoside reverse transcriptase inhibitors.

ABSTRACT The aim of this study was to determine the metabolizable energy requirements for maintenance (MEm) and growth (MEg) of llamas and alpacas, by the comparative slaughter technique, at 4200 m above sea level. Twenty male llamas (106.6 ± 7.7 kg live weight, LW) and 20 male alpacas (55.7 ± 4.9 kg LW), both of two years of age, were subdivided into 5 groups of 4 animals each, per species. One group was slaughtered at the beginning of the study to measure the initial body energy content, and the remaining four groups were fed over a period of 55 days on a mixture of chopped hay of oats and Lucerne at four levels of feed (94.2% dry matter, DM): maintenance, intermediate low, intermediate high and ad libitum; corresponding to 40, 50, 60 and 70 g DM/kg LW0.75, respectively. All animals were slaughtered at the end of the experiment to determine retained energy (RE). Another group of four animals per species were used in a parallel in vivo metabolism study to determine the metabolizable energy (ME) content of the diet. Samples of the diet, faeces, and the animal body, were analysed for gross energy contents. The ME content of the diet did not differ between levels if feeding or species, 2226 ± 206 and 2212 ± 165 kcal/kg DM for llamas and alpacas, respectively. The requirements of MEm estimated as heat production at zero RE differed between species (p<0.01): 86.4 and 82.6 kcal/kg LW0.75 for llamas and alpacas, respectively, with corresponding partial efficiencies (km) of 0.77 and 0.66. The requirement of MEg was 9.2 and 11.4 kcal/g LW gain for llamas and alpacas, respectively, with corresponding partial efficiencies (kg) of 0.23 and 0.34. It is concluded that the ME m requirements of llamas and alpacas, at high altitude are independent from each other and about 27% lower than those reported for ruminants.

RESUMEN El objetivo del estudio fue determinar los requerimientos de energía metabolizable de mantenimiento (EMm) y ganancia de peso vivo (EMg) de llamas y alpacas, mediante la técnica de sacrificio comparativo, a 4200 m de altitud. Se utilizaron 20 llamas machos (106.6 ± 7.7 kg de peso vivo, PV) y 20 alpacas machos (55.7 ± 4.9 kg PV), ambos grupos de 2 años de edad, divididos en 5 grupos de 4 animales por especie. Un grupo fue sacrificado al inicio del estudio para medir la energía corporal inicial, mientras que los cuatro grupos restantes fueron alimentados durante 55 días con una mezcla de heno picado de avena y alfalfa, en cuatro niveles de oferta de dieta (94.2% materia seca, MS): mantenimiento, intermedio bajo, intermedio alto y ad libitum; correspondientes a 40, 50, 60 y 70 g MS/kg PV0.75, respectivamente. Todos los animales fueron sacrificados al final del experimento para determinar la retención de energía (RE). Otro grupo de 4 animales por especie acompañó en paralelo con experimentos de metabolismo convencional in vivo, para determinar la energía metabolizable (EM) de la dieta. Las muestras de la dieta, heces y del cuerpo animal se analizaron mediante calorimetría de bomba. El contenido de EM de la dieta fue similar entre niveles de consumo y entre especies, 2226 ± 206 y 2212 ± 165 kcal/kg MS para llamas y alpacas, respectivamente. El requerimiento de EMm, estimado como la producción de calor en retención cero de energía, fue diferente entre especies (p<0.01), 86.4 y 82.6 kcal/kg PV0.75, para llamas y alpacas, respectivamente, con las correspondientes eficiencias parciales (km) de 0.77 y 0.66. El requerimiento de EMg fue 9.2 y 11.4 kcal/g de ganancia de PV, respectivamente, con sus respectivas eficiencias parciales (kg) de 0.23 y 0.34. Se concluye que los requerimientos de EMm de llamas y alpacas en gran altitud son independientes entre sí, y menores en aproximadamente 27% con relación a los reportados para rumiantes.

Background: The main cause of virological failure during AIDS treatment is the resistance to antiretroviral medications (ARV). Aim: To search for mutations associated with ARV resistance in recently HIV-1 infected patients naïve to treatment, in Chile. Material and Methods: Patients over 18 years old with HIV-1 infection, naïve to antiretroviral drugs before the study were included. Patients with CD4 cell counts less than 200 cells/mm³, viral load below 2.000 copies/mL or any condition indicative of advanced AIDS were excluded. Criteria for diagnosis of recent infection (< 18 months) were a previous negative test for HIV antibodies or a history of an acute retroviral syndrome in the past 18 months. Resistance to drugs was analyzed using the TRUGENEtm HIV-1 assay from Bayer and the OpenGene DNA sequencing system. Results: Ninety nine percent of patients had at least one mutation, 27% had 4 or more mutations, but high level resistance to ARV was found only in 2.7% of cases. Point mutations for non nucleoside reverse transcriptase inhibitors (NNRTI) were detected in 4.1% of cases (K103N in 1 patient, V179D in 2 patients), for nucleoside reverse transcriptase inhibitors (NRTI) in 8.1% of cases (T215S in 1 patient, V118I in 4 patients, M41L in 1 patient) and for protease inhibitors (PI) in 1.3% of cases. All mutations detected in the protease gene were secondary. Of these, the most common were L63P/T (38 patients), L10I/V (27 patients) and V77I (26 patients). Resistance to two or more antiretroviral classes was not detected. Conclusions: This study supports that, by now, primary resistance has a low prevalence in Chile. Therefore, a genotyping test before starting antiretroviral therapy is not necessary.

We report a 42 years old HIV negative male admitted for fever of unknown origin. Initial laboratory evaluation showed elevated hepatic transaminases and alkaline phosphatase and an hipodense hepatic imagen was visualized in the CT scan. Hepatic biopsy demonstrated tuberculous granulomas and alcohol fast acid rods with Ziehl Neelsen stain. Anti-tuberculous treatment resulted in resolution of fever, improvement of general condition and normalization of laboratory parameters

Reportamos el caso de un hombre de 42 años, seronegativo para VIH, con fiebre de origen desconocido (FOD), asociada a elevación de transaminasas y fosfatasas alcalinas con patrón colestásico e imágenes hepáticas hipodensas en la tomografía axial computada. La biopsia hepática demostró la presencia de granulomas tuberculosos con visualización de un bacilo con alcohol-ácido resistencia. El cuadro respondió al tratamiento con fármacos antituberculosos presentando caída de curva febril, mejoría del estado general y normalización de parámetros de laboratorio

FUNDAMENT: To show our initial experience in the TUR of prostate with bipolar axipolar bistoury. MATERIAL AND METHODS: Five patients with an average age of 72 years old, were operated between may and june 2002. They showed important increased in questionnaire symptoms (IPSS). The average ecografic volume has been 57.4 g. We employed Gyrus® resector and physiological salt solution for continue irrigation. RESULTS: The average operative time was 70 minutes. None of the patients showed hyponatremia needier blood transfusion. In all the cases the sound was removed 48 hours after operation, one of them have urinary retention (UR) and need sound tow more days. Hospital stay was tree days except the patient how had UR. At 1 and 6 month there is improvement in the IPSS. CONCLUTIONS: TUR of prostate with bipolar axipolar bistoury can avoid the secondary effects of glicine and allows us to work with prostates of bigger volumes due to we have more time to do it. Nevertheless bigger and better studies are required to value the effectiveness of this new technology opposite the TUR of prostate with monopolar bistoury which keeps being the gold standard.

FUNDAMENTO: Presentar nuestra experiencia inicial en la RTU de próstata con bisturí bipolar axipolar. MATERIAL Y MÉTODO: Los sujetos de estudio han sido 5 pacientes con una edad media de 72 años intervenidos, entre mayo y junio de 2002. Todos presentaban valores elevados en el cuestionario de síntomas (IPSS). El volumen ecográfico medio fue 57,4 g. Se empleó el resector Gyrus® y suero fisiológico para irrigación. RESULTADOS: La duración media de la intervención fue de 70 minutos. Ningún paciente presentó hiponatremia ni precisó transfusión. En todos los casos se retiró la sonda a las 48 horas, produciéndose una retención aguda de orina (RAO), que precisó sonda dos días más. Todos fueron dados de alta al tercer día, salvo el paciente que presentó el episodio de RAO. Al mes y a 6 meses hay una mejoría mantenida del IPSS. CONCLUSIONES: La RTU de próstata con bisturí bipolar axipolar puede evitar los efectos secundarios de la reabsorción de glicina y permite abordar próstatas de mayor volumen al disponer de más tiempo para hacerlo. No obstante, hacen falta estudios más amplios para valorar la eficacia de esta nueva tecnología, frente a la RTU de próstata con bisturí monopolar que sigue siendo el patrón oro.

Nosocomial infections demand an exceptional antiinfective therapy because of its severity and resistance to first line antibiotics. Intensive care units must implement policies to avoid the selection of multiresistant strains that supersede the efficacy of these antibiotics; useful to reduce this selective process are: reduction of surgical prophylaxis practice, cycling of antibiotics, shortage of treatment schedules and to implement the de-escalating therapy of antimicrobial agents based on a rapid and sensible microbiological diagnosis. Multiple strategies proposed to optimize the antiinfective effect of antibiotic treatment are reviewed: application of pharmacokinetic and pharmacodinamic concepts, use of new lipid formulations of amphotericin B, inhalatory aminoglycosides and lock therapy for central vascular catheters infections. Selective decontamination in mechanically ventilated patients and topical mupirocin treatment of methicillin resistant Staphylococcus aureus nasal carriers are tools to prevent some severe infections

Las infecciones nosocomiales en pacientes críticos exigen de una terapia antinfecciosa de excepción por la gravedad de las mismas y por su refractariedad a los antimicrobianos habituales. En las unidades de pacientes críticos deben implementarse políticas para evitar la selección de cepas multiresistentes que comprometa la eficacia de estos antimicrobianos; útiles para limitar esta selección son: reducción en el uso de profilaxis quirúrgica, rotación de antimicrobianos, abreviar los plazos de tratamiento e implementar el de-escalamiento de agentes antibacterianos apoyado en un diagnóstico microbiológico rápido y sensible. Se revisan las múltiples estrategias propuestas para optimizar el efecto antimicrobiano de los antibióticos: aplicación de conceptos farmacocinéticos y farmacodinámicos, uso de nuevas presentaciones lipídicas de anfotericina B, el empleo inhalatorio de aminoglucósidos y la terapia «de candado» para las infecciones de catéteres vasculares centrales. Se discuten también la descontaminación selectiva en el paciente en ventilación mecánica y el tratamiento con mupirocina tópica de la portación nasal de Staphylococcus aureus resistente a meticilina como herramientas para prevenir algunas infecciones severas