USO DEL ENSILADO BIOLÓGICO DE PESCADO EN LA ALIMENTACIÓN DE CUYES MEJORADOS

Se evaluó el efecto del ensilado de pescado en dietas para cuyes (Cavia porcellus). Se emplearon 80 cuyes de la línea Perú (1/2 sangre) destetados a los 14 ± 3 días de edad, y distribuidos en cuatro tratamientos de 20 animales cada uno. Los tratamientos consistieron en dietas con niveles de 10 (D10), 20 (D20) y 30% (D30) de ensilado de pescado. El estudio duró 10 semanas y se dividió en tres periodos: 0-42, 42-70 y 0-70 días. La ganancia de peso y el consumo fue mayor en D10, D20 y D30 con relación a D0 (p<0.05) y no hubo diferencias entre D10, D20 y D30 (p>0.05). La conversión alimenticia fue mejor en D20 y D30 en todos los periodos. El rendimiento de canal fue mejor en D30 y la retribución económica fue mejor en D20. La prueba degustativa indicó que el olor y sabor de la carne se afectó en D30. Se concluye que el uso de ensilado de pescado en las raciones mejoró el rendimiento productivo del cuy; siendo factible, en términos organolépticos y econó- micos, incorporarlo hasta niveles del 20% de la ración.The study evaluated the effect of the fish silage on feed rations for Guinea Pig (Cavia porcellus). Eighty guinea pigs of the Peruvian line (1/2 blood) , weaned at 14 ± 3 days of age, were used. The treatments consisted of different levels of fish silage: 0 (D0), 10 (D10), 20 (D20) and 30% (D30). The study lasted 10 weeks and was divided in three stages: 0-42, 42-70 and 0-70 days. Body weight gain and food intake was higher in D10, D20 and D30 as compared to DO (p<0.05), whereas no differences were found between D10, D20 and D30. In all stages, food conversion was higher in D20 and D30. The carcass performance was better in D30 and the economic benefit was better in D20. The organoleptic trial suggested that meat flavor and smell were affected on D20. It was concluded that the use of fish silage in the rations improved the productive performance of the guinea pig, where 20% content was the most appropiate based on organoleptic and economic terms

ESTUDIO DE REPLICABILIDAD DE DOS SUJETOS EXPERIMENTALES EN UN TRABAJO DE INVESTIGACIÓN DE CONDUCTA DISCRIMINATORIA

Objetivo: Analizar el grado de replicabilidad experimental de un método de condicionamiento y discriminación aplicado a dos sujetos de trabajo. Materiales y métodos: Se utilizaron para la investigación sobre los métodos de condicionamiento y discriminación, 2 sujetos experimentales introducidos dentro de la caja de Skinner Lafayette con una división de madera. Se consideró a las luces de la caja de Skinner Lafayette como estímulos a discriminar y nicovita como recompensa y refuerzo de la conducta deseada. Se estableció la línea base y se registraron 10 conductas iniciales. Se fortaleció la conducta de cruce como conducta principal para el refuerzo, se incluyeron las luces como variable a discriminar para la obtención de la recompensa. Resultados: Considerando las frecuencias observadas y obtenidas durante la aplicación del experimento, más del 90% de los resultados del sujeto experimental N°1 se asemejan a los resultados del sujeto experimental N°2, y en las conductas número 7 (palanca) y conducta numero 8 (luz) existe una variabilidad, que a comparación del primer sujeto experimental, estas últimas aumentan su frecuencia al presentar luz apagada, además de que hay una variación en la cantidad de cruces en el segundo sujeto. A pesar de lo expuesto, el aumento de la conducta objetivo en ambos sujetos experimentales se logró de manera satisfactoria al igual que la conducta discriminatoria en ambos casos, demostrando la capacidad de replicabilidad del experimento. Conclusión: El experimento realizado arroja resultados fiables que cuentan con la adecuada replicabilidad de resultados para poder aplicarse en otros sujetos experimentales

A Multi-Center Study to Evaluate the Performance of Phage Amplified Biologically Assay for Detecting TB in Sputum in the Pulmonary TB Patients

Objective: To evaluate the performance of phage amplified biologically assay (PhaB) for detecting tuberculosis (TB) in sputum in the pulmonary tuberculosis (PTB) patients. Methods: Shanghai Tuberculosis Key Laboratory of Shanghai Pulmonary Hospital participated in the project in collaboration with the laboratories of six hospitals and a total of 1660 eligible participants (1351 PTB patients and 309 non-TB patients) were included in the study. The sputum samples from the participants were detected by smear microscopy, PhaB, and Löwenstein-Jensen (L-J) culture method, respectively. Results: The overall sensitivity of PhaB were higher than that of L-J culture and smear microscopy (p,0.05). The sensitivity of PhaB for detecting smear-negative specimens was obviously higher than that of L-J culture (p,0.05). Compared with L-J culture, the overall sensitivity, specificity, PPV, NPV, ACC and Kappa value of PhaB were 98.4 (95 % Cl: 96.9–99.3), 71.6 (95% Cl: 68.4–74.6), 67.7, 98.7, 81.7 % and 0.643, respectively. The detection median time of PhaB only needed 48 hours, which was significantly less than that (31 days) of L-J culture method. Conclusion: PhaB method is a rapid and sensitive method for detecting TB in sputum in PTB patients; especially for th

A Randomised Controlled Trial to Assess the Efficacy of Dihydroartemisinin-Piperaquine for the Treatment of Uncomplicated Falciparum Malaria in Peru

Background. Multi-drug resistant falciparum malaria is an important health problem in the Peruvian Amazon region. We carried out a randomised open label clinical trial comparing mefloquine-artesunate, the current first line treatment in this region, with dihydroartemisinin-piperaquine. Methods and Findings. Between July 2003 and July 2005, 522 patients with P. falciparum uncomplicated malaria were recruited, randomized (260 with mefloquine-artesunate and 262 with dihydroartemisinin-piperaquine), treated and followed up for 63 days. PCR-adjusted adequate clinical and parasitological response, estimated by Kaplan Meier survival and Per Protocol analysis, was extremely high for both drugs (99.6% for mefloquine-artesunate and 98.4% and for dihydroartemisinin-piperaquine) (RR: 0.99, 95%CI [0.97-1.01], Fisher Exact p=0.21). All recrudescences were late parasitological failures. Overall, gametocytes were cleared faster in the mefloquine-artesunate group (28 vs 35 days) and new gametocytes tended to appear more frequently in patients treated with dihydroartemisinin-piperaquine (day 7: 8 ( 3.6%) vs 2 (0.9%), RR: 3.84, 95%CI [0.82-17.87]). Adverse events such as anxiety and insomnia were significantly more frequent in the mefloquine-artesunate group, both in adults and children. Conclusion. Dihydroartemisinin-piperaquine is as effective as mefloquine-artesunate in treating uncomplicated P. falciparum malaria but it is better tolerated and more affordable than mefloquine-artesunate (US$1.0 versus US$18.65 on the local market). Therefore, it should be considered as a potential candidate for the first line treatment of P. falciparum malaria in Peru. Trial Registration. ClinicalTrials.gov NCT00373607 [http://www.clinicaltrials.gov/ct/show/NCT00373607]

A retrospective analysis of the change in anti-malarial treatment policy: Peru

<p>Abstract</p> <p>Background</p> <p>National malaria control programmes must deal with the complex process of changing national malaria treatment guidelines, often without guidance on the process of change. Selecting a replacement drug is only one issue in this process. There is a paucity of literature describing successful malaria treatment policy changes to help guide control programs through this process.</p> <p>Objectives</p> <p>To understand the wider context in which national malaria treatment guidelines were formulated in a specific country (Peru).</p> <p>Methods</p> <p>Using qualitative methods (individual and focus group interviews, stakeholder analysis and a review of documents), a retrospective analysis of the process of change in Peru's anti-malarial treatment policy from the early 1990's to 2003 was completed.</p> <p>Results</p> <p>The decision to change Peru's policies resulted from increasing levels of anti-malarial drug resistance, as well as complaints from providers that the drugs were no longer working. The context of the change occurred in a time in which Peru was changing national governments, which created extreme challenges in moving the change process forward. Peru utilized a number of key strategies successfully to ensure that policy change would occur. This included a) having the process directed by a group who shared a common interest in malaria and who had long-established social and professional networks among themselves, b) engaging in collaborative teamwork among nationals and between nationals and international collaborators, c) respect for and inclusion of district-level staff in all phases of the process, d) reliance on high levels of technical and scientific knowledge, e) use of standardized protocols to collect data, and f) transparency.</p> <p>Conclusion</p> <p>Although not perfectly or fully implemented by 2003, the change in malaria treatment policy in Peru occurred very quickly, as compared to other countries. They identified a problem, collected the data necessary to justify the change, utilized political will to their favor, approved the policy, and moved to improve malaria control in their country. As such, they offer an excellent example for other countries as they contemplate or embark on policy changes.</p

South American Plasmodium falciparum after the Malaria Eradication Era: Clonal Population Expansion and Survival of the Fittest Hybrids

Malaria has reemerged in many regions where once it was nearly eliminated. Yet the source of these parasites, the process of repopulation, their population structure, and dynamics are ill defined. Peru was one of malaria eradication's successes, where Plasmodium falciparum was nearly eliminated for two decades. It reemerged in the 1990s. In the new era of malaria elimination, Peruvian P. falciparum is a model of malaria reinvasion. We investigated its population structure and drug resistance profiles. We hypothesized that only populations adapted to local ecological niches could expand and repopulate and originated as vestigial populations or recent introductions. We investigated the genetic structure (using microsatellites) and drug resistant genotypes of 220 parasites collected from patients immediately after peak epidemic expansion (1999–2000) from seven sites across the country. The majority of parasites could be grouped into five clonal lineages by networks and AMOVA. The distribution of clonal lineages and their drug sensitivity profiles suggested geographic structure. In 2001, artesunate combination therapy was introduced in Peru. We tested 62 parasites collected in 2006–2007 for changes in genetic structure. Clonal lineages had recombined under selection for the fittest parasites. Our findings illustrate that local adaptations in the post-eradication era have contributed to clonal lineage expansion. Within the shifting confluence of drug policy and malaria incidence, populations continue to evolve through genetic outcrossing influenced by antimalarial selection pressure. Understanding the population substructure of P. falciparum has implications for vaccine, drug, and epidemiologic studies, including monitoring malaria during and after the elimination phase

Evaluation of rifampicin and isoniazid susceptibility testing of Mycobacterium tuberculosis by a mycobacteriophage D29-based assay

Conventional methods for determining drug susceptibility of Mycobacterium tuberculosis require several weeks to obtain results, limiting their usefulness; automated methods and those based on molecular biology techniques have been able to reduce the turnaround time, but their high cost and need for sophisticated equipment restrict their use in developing countries. The goal of the present study was to evaluate the diagnostic accuracy of a rapid (3-4 days) low-cost test based on the use of mycobacteriophage D29 to determine the susceptibility of strains of M. tuberculosis to rifampicin (RIF) and isoniazid (INH). Results obtained show that susceptibility testing for RIF has a high diagnostic accuracy as compared to the standard indirect proportion method on Löwenstein-Jensen medium (sensitivity 100% and specificity 98%). Given the association between the resistance to RIF and INH, which define multidrug resistance (MDR), this test seems suitable for rapid detection of MDR tuberculosis strains (kappa=0.978). Susceptibility testing for INH using mycobacteriophage D29 had a good but lower diagnostic accuracy as compared to the standard method (sensitivity 80.4% and specificity 80.8%); the test would then be of limited usefulness in the management of tuberculosis patients. Further studies to determine the relationship of mycobacteriophage D29 tests to in vivo correlates of sensitivity to specific antituberculosis drugs are warranted