A smartphone game to prevent HIV among young Kenyans: local perceptions of mechanisms of effect.

Electronic games delivered via smartphones have the potential to become valuable tools in HIV prevention in high-prevalence and low-resource international settings. To ground theoretical elaboration around novel mHealth interventions in contextual realities, it is important to understand the mechanisms of their effects as perceived by local populations. Such perspectives are particularly important when working cross-culturally. 'Tumaini' is an interactive narrative-based smartphone game that uses a 'choose-your-own-adventure' format. It is designed to prevent HIV among young African adolescents (aged 11-14) by increasing age and condom use at first sex. It was developed with a US-based commercial game developer and is grounded in social behavioral theory, evidence-based practice and contextually relevant scenarios. In a 2017 randomized pilot study (n = 60) in Western Kenya, 'Tumaini' showed promising effects on behavioral mediators of sexual debut. In subsequent focus group discussions, adolescent participants and their parents shared their perceptions of the game's mechanisms of effect, which included motivation to play, future orientation, decision-making, relationship to a diverse range of characters and a bridging of the virtual and real worlds. These findings align with our theoretical framework, confirm its successful translation into the intervention and will inform mediation analyses in an upcoming efficacy trial.

Long-term survival after photodynamic therapy for esophageal cancer.

BACKGROUND/AIMS: Photodynamic therapy (PDT) has been adapted to the endoscopic treatment of digestive cancer, but its indications and efficacy remain uncertain. The aim of this study was to assess its feasibility in the curative treatment of small esophageal tumors. METHODS: From 1983 to 1991, PDT was used to treat 123 patients with esophageal cancer who were recommended for nonsurgical treatment of squamous cell carcinoma (n = 104) and adenocarcinoma (n = 19). Endoscopic ultrasonography (EUS) was performed in 88 patients; 61 were staged uT1 and 27 were staged uT2. A hematoporphyrin derivative was injected 72 hours before laser irradiation with a 630-nm dye laser. PDT was applied alone in 56 patients and as part of a multimodal protocol in the 67 others. RESULTS: The complete response rate at 6 months was 87%. The 5-year survival rate was 25% +/- 6%, and the 5-year disease-specific survival rate was 74% +/- 5%. The complete response rate and survival rate were not different (1) between the PDT alone and the PDT multimodal treatment groups, (2) between the adenocarcinoma and squamous cell carcinoma groups, and (3) between the uT1 and uT2 EUS groups. PDT-related complications were esophageal stenosis (n = 43) and cutaneous photosensitization (n = 16). CONCLUSIONS: In patients with small esophageal tumors who pose high surgical risk, photodynamic therapy is an effective treatment.

[Laser treatment of villous rectal tumors]. / Traitement laser des tumeurs villeuses rectales.

The treatment of villous rectal tumors with the Nd: YAG laser is characterized by its great effectiveness (almost 90% of complete eradication in our series of 100 cases), and by its great tolerance. It may be applied to all patients regardless of their condition. In case of running villous tumors, complete destruction is more difficult to obtain and the laser method must be weighed against the risks and advantages of radical surgery. The problems raised by frequent foci of adenocarcinoma, which characterize large villous lesions, is minimized by a strict therapeutic protocol: in fact, the foci are superficial in the majority of the cases and they do not decrease the percentage of complete destruction; in other cases, it is possible, by repeated histological controls, in case of persisting positive biopsies, to modify, in time, the choice of treatment.

Los rayos laser en gastroenterologia. / Laser rays in gastroenterology

Se hace una breve descripcion de los rayos Laser, de sus principales fuentes, variedades y caracteristicas. Se discuten las indicaciones actuales de los rayos Laser en gastroenterologia, destacando el tratamiento de los sangramientos digestivos (varices esofagicas, ulcera peptica, gastritis erosivas, angiodisplasias, etc.) y el de los tumores benignos y malignos de esofago, estomago y colon. En cada uno de estos campos se resumen las indicaciones actuales, los resultados alcanzados, las limitaciones y los riesgos. Uno de los aspectos mas interesantes es la posibilidad de detectar y de tratar focos neoplasicos mediante el empleo de Laser a colorantes que son captados por las celulas neoplasicas y luego activados por los rayos, ejerciendose una accion local selectiva