Studies on Trypanosoma rangeli Tejera, 1920: V - Developmental pattern in the alimentary canal of Rhodnius prolixus

The morphological sequence of Trypanosoma rangeli development in the alimentary canal of Rhodnius prolixus, is described, with observation made in dissected guts from 6 hours to 45 days post-infection. No metacyclic-forms are produced in the digestive tract at any time, and transmission by the contaminative route must be considered atypical. Amastigotes appear to be an essential stage in the development of T. rangeli in the gut of R. prolixus. The epidemiological importance of the developmental pattern of T. rangeli in the vector´s gut is discussed, and its usefulness for aging infection is considered.

Anothor Trypanosoma, distinct from T. cruzi, multiplies in the lumen of the anal glands the opossum Didelphis marsupialis

Epimastigotes were found multiplying in the anal glands and in hemocultures of an opossum; rare metacyclics were seen in the cultures. The flagellate is possibly T. (Megatrypanum) freitasi Rego, Magalhães & Siqueira, 1957, but its final identification is still pending.

L' esport a la Televisió de Catalunya: la creació d'un canal esportiu-cultural: Canal 33

Aquest treball es va presentar a l’Assignatura de Campus “Esport, Olimpisme i Societat” del curs 1995/96 i tracta de l'evolució de la programació esportiva a la Televisió de Catalunya des de la seva creació, així com dels orígens i història del Canal 33.

A Multicenter Randomized Clinical Trial of Primary Anastomosis or Hartmann's Procedure for Perforated Left Colonic Diverticulitis With Purulent or Fecal Peritonitis.

OBJECTIVES: : To evaluate the outcome after Hartmann's procedure (HP) versus primary anastomosis (PA) with diverting ileostomy for perforated left-sided diverticulitis. BACKGROUND: : The surgical management of left-sided colonic perforation with purulent or fecal peritonitis remains controversial. PA with ileostomy seems to be superior to HP; however, results in the literature are affected by a significant selection bias. No randomized clinical trial has yet compared the 2 procedures. METHODS: : Sixty-two patients with acute left-sided colonic perforation (Hinchey III and IV) from 4 centers were randomized to HP (n = 30) and to PA (with diverting ileostomy, n = 32), with a planned stoma reversal operation after 3 months in both groups. Data were analyzed on an intention-to-treat basis. The primary end point was the overall complication rate. The study was discontinued following an interim analysis that found significant differences of relevant secondary end points as well as a decreasing accrual rate (NCT01233713). RESULTS: : Patient demographics were equally distributed in both groups (Hinchey III: 76% vs 75% and Hinchey IV: 24% vs 25%, for HP vs PA, respectively). The overall complication rate for both resection and stoma reversal operations was comparable (80% vs 84%, P = 0.813). Although the outcome after the initial colon resection did not show any significant differences (mortality 13% vs 9% and morbidity 67% vs 75% in HP vs PA), the stoma reversal rate after PA with diverting ileostomy was higher (90% vs 57%, P = 0.005) and serious complications (Grades IIIb-IV: 0% vs 20%, P = 0.046), operating time (73 minutes vs 183 minutes, P < 0.001), hospital stay (6 days vs 9 days, P = 0.016), and lower in-hospital costs (US $16,717 vs US $24,014) were significantly reduced in the PA group. CONCLUSIONS: : This is the first randomized clinical trial favoring PA with diverting ileostomy over HP in patients with perforated diverticulitis.

"How I Do It"-Radical Right Colectomy with Side-to-Side Stapled Ileo-Colonic Anastomosis.

BACKGROUND AND OBJECTIVE: Standardization of surgical technique helps to reproduce excellent clinical outcomes, especially in teaching institutions. We aim to describe in detail our established approach for oncological right colectomy. TECHNIQUE: The right colon is mobilized in a five-step latero-inferior approach starting off with (1) the terminal ileum, visualizing the duodenum and the head of pancreas. (2) The ascending colon is dissected from the retroperitoneum, and takedown of the hepatic flexure is completed coming retrograde from the transverse colon (3). (4) Transection of the remaining retroperitoneal attachments completes exposure of the duodenum and mobilization of the right colon. (5) Ileocolic vessels are dissected out and divided close to their origin, and the mesocolon is divided. We then establish intestinal continuity by use of a side-to-side stapled technique. (1) The arms of a linear cutting stapler are inserted via transverse incisions at the anti-mesenteric sides of the terminal ileum and the transverse colon (tenia) and fired. (2) The enterotomy site is closed by removal of the specimen using a second transverse firing of the linear cutting stapler. An important final step is the (3) reinforcement of the anastomotic ends and the crossing of the staple lines; an omental patch and closure of the mesenteric window are optional. CONCLUSION: The suggested standardized five-step lateral-to-medial dissection of the right colon and the three-step side-to-side stapled technique for ileo-colonic anastomosis are easy to learn and to reproduce. Careful adherence to pivotal technical details will help to obtain an optimal oncological outcome and a consistently low leak rate around 2 %.

Trypanosoma cruzi in the anal glands of urban opossums: I- isolation and experimental infections

Opossums (Didelphis marsupialis) captured in intensely urbanized areas of the city of Caracas, Venezuela, were found infected with Trypanosoma cruzi. The developmental cycle of trypomastigote-epimastigote-metacyclic infective trypomastigote, usually occurring in the intestine of the triatomine vector, was taking place in the anal odoriferous glands of the opossums. Material from the glands, inoculated in young, healthy opossums and white mice by different routes, subcutaneously, intraperitoneally, orally, and into the eye, induced T. cruzi infections in all animals. Parasitemia, invasion of cardiac and skeletal muscle, and intracellular multiplication of amastigotes were observed. Inoculation of metacyclics from anal glands, cultured in LIT medium, gave equivalent results. All opossums survived; all mice died. Excreta of opossums may thus transmit Chagas' disease by contamination, even in urban areas where insect vectors are not present.

El canal Segarra-Garrigues y la (de)construcción de los problemas del agua: un estudio centrado en el papel del experto, los procesos decisionales y la generación participativa del conocimiento

Este trabajo de investigación se centra en la problemática hídrica y, concretamente, en el enfoque con el que, actualmente, se describen y se tratan estos problemas. Así, se analiza el modelo estructuralista hidráulico como una de estas fuentes de interpretación y proposición. Pero, también, se estudia cómo ha contribuido la labor científica que realizan en este contexto los expertos sobrre aguas -principalmente, ingenieros y técnicos- a establecer el "framing" predominante. Con la preocupación de estar tratando con un recurso vital que ante una distribución y gestión hídricas deficientes o inapropiadas genera problemas prácticos de urgente resolución, se empieza a cuestionar, como hacen las nuevas concepciones como la gestión integrada de cuencas hidrográficas o la Nueva Cultura del Agua, el modo actual de enmarcar el problema. En este sentido, se adopta como objetivo tratar de reverter la dinámica de crecimiento de la demanda y encontrar fórmulas no centralizadas de gestión, que no requieran un conocimiento completo del sistema hidrológico y de gestión, que no detenten visiones fragmentadas de la situación hídrica y que no mantengan un "framing" estático y determinista. Y, para ello, se toma como inicio, lo que sucede en los conflictos en torno al agua. Así, se considera la tensión que existe entre "nuevos" y "viejos" paradigmas no sólo una discusión académico-teórica, sino, también una cuestión de gobernabilidad hídrica. De este modo, se presenta como una oportunidad para el cambio tanto la situación compleja e incierta que caracteriza y envuelve la gestión del agua como la diversidad de "miradas" al problema (y de soluciones) que existen en la contingencia social. Además, se contemplan, como sugerencias de innovación conceptual y procedural, los mecanismos de interacción, comunicación y presión que surgen en estos contextos. Se aborda el caso del canal de riego del Segarra-Garrigues en Lleida, precisamente, para indagar en todos estos aspectos, como un ejemplo de este encuentro entre nuevas realidades y anacrónicas incercias y de la inquietud de algunos actores por redefinir el "framing" hegemónico. Para ello, se da especial importancia a los procesos de toma de decisiones y de generación del conocimiento, prestando atención a cómo condicionan, en los problemas y en la búsqueda de soluciones, la filosofía e ideología científica y política empleadas en el marco del agua. De este análisis se desprenden algunas opciones para experimental en etapas venideras de la investigación. En este documento, entonces, se discute sobre qué otros modes de investigar-decidir-actuar podrían darse, pero también, se describe qué se ha hecho, hasta el momento, al respecto. En este sentido, aparecen cuestiones como la redeficinión del rol del experto-investigador, la práctica participativa en la generación del conocimiento, la sinergia entre las motivaciones científico-teóricas con las preocupaciones locales y la integración entre el estudio y los procesos de (auto)organizativos que se dan en el conflicto. Y, en definitiva, se hacen patentes muchos de los retos que enfrentan hoy en día la gestión y placificación hidrológicas.

Systemic modulation of peripheral eosinophilia (air pouch model) in Schistosoma mansoni infection

Schistosoma mansoni infection induces in their hosts a marked and sustained eosinophilia, which is influenced or modulated by complex mechanisms, that vary according to the phase of infection. To address this phenomenon, we used the air pouch (AP) model in control and infected Swiss webster mice, analyzing the cellular, tissue response and local expression of adhesion molecules [CD18 (beta 2-chain), CD44, ICAM-1 (CD54), L-selectin (CD62L), CD49d (alpha 4-chain), LFA1 (CD11a)]. Infected animals were studied at 3 (pre-oviposition phase), 7 (acute phase), and 14 (chronic phase) weeks after infection (5-6 mice/period of infection). Normal mice were age-matched. Results showed that after egg stimulation, compared with matched controls, the infected mice, at each point of infection, showed a lower eosinophil response in the acute (7 weeks) and chronic phase (14 weeks) of infection. However, when the infected mice were in pre-oviposition phase (3 weeks) their eosinophil response surpassed the control ones. In the AP wall of infected mice, a significant decrease in the expression of ICAM-1 and CD44 in fibroblastic-like cells and a reduction in the number of CD18 and CD11a in migratory cells were observed. The other adhesion molecules were negative or weakly expressed. The results indicated that in the air pouch model, in S. mansoni-infected mice: (1) eosinophil response is strikingly down-regulated, during the acute ovular phase; (2) in the pre-oviposition phase, in contrast, it occurs an up-regulatory modulation of eosinophil response, in which the mechanisms are completely unknown; (3) in the chronic phase of the infection, the down modulation of eosinophil response is less pronounced; 4) Down-regulation of adhesion molecules, specially of ICAM-1 appear to be associated with the lower eosinophil response.

Helminth Parasites of Conventionally Maintained Laboratory Mice: II- Inbred Strains with an Adaptation of the Anal Swab Technique

Worm burdens recovered from inbred mice strains, namely C57Bl/6, C57Bl/10, CBA, BALB/c, DBA/2 and C3H/He, conventionally maintained in two institutional animal houses in the State of Rio de Janeiro, RJ, Brazil, were analyzed and compared, regarding their prevalences and mean intensities.Three parasite species were observed: the nematodes Aspiculuris tetraptera, Syphacia obvelata and the cestode Vampirolepis nana. A modification of the anal swab technique is also proposed for the first time as an auxiliary tool for the detection of oxyurid eggs in mice