Entomopathogenic fungi and their potential for the management of Aedes aegypti (Diptera: Culicidae) in the Americas

Classical biological control has been used extensively for the management of exotic weeds and agricultural pests, but never for alien insect vectors of medical importance. This simple but elegant control strategy involves the introduction of coevolved natural enemies from the centre of origin of the target alien species. Aedes aegypti - the primary vector of the dengue, yellow fever and Zika flaviviruses - is just such an invasive alien in the Americas where it arrived accidentally from its West African home during the slave trade. Here, we introduce the concept of exploiting entomopathogenic fungi from Africa for the classical biological control of Ae. aegypti in the Americas. Fungal pathogens attacking arthropods are ubiquitous in tropical forests and are important components in the natural balance of arthropod populations. They can produce a range of specialised spore forms, as well as inducing a variety of bizarre behaviours in their hosts, in order to maximise infection. The fungal groups recorded as specialised pathogens of mosquito hosts worldwide are described and discussed. We opine that similar fungal pathogens will be found attacking and manipulating Ae. aegypti in African forests and that these could be employed for an economic, environmentally-safe and long-term solution to the flavivirus pandemics in the Americas.

Paternal aging and increased risk of congenital disease, psychiatric disorders, and cancer / 亚洲男科学杂志(英文版)

As couples are increasingly delaying parenthood, the effect of the aging men and women on reproductive outcomes has been an area of increased interest. Advanced paternal age has been shown to independently affect the entire spectrum of male fertility as assessed by reductions in sperm quality and fertilization (both assisted and unassisted). Moreover, epidemiological data suggest that paternal age can lead to higher rates of adverse birth outcomes and congenital anomalies. Mounting evidence also suggests increased risk of specific pediatric and adult disease states ranging from cancer to behavioral traits. While disease states associated with advancing paternal age have been well described, consensus recommendations for neonatal screening have not been as widely implemented as have been with advanced maternal age.

Bridging the practice and science of employee engagement: a qualitative investigation / Uniendo la ciencia y la práctica del engagement laboral: una investigación cualitativa

While the practice and the science of employee engagement continue to run on largely separate paths, the science of engagement continues to evolve with ongoing incremental refinements to existing models and measures. This qualitative study sought to map the extent of the science-practice divide and to further inform the content of the science and the practice of employee engagement. Interview data obtained from 51 senior operational and human resource managers of a large multi-national mining company revealed that whereas a considerable overlap is apparent in the way that scientists and practitioners view the nature and the drivers of employee engagement, there are also key differences and differences of emphasis. Consistent with recent research, the importance of a reciprocal or two-way partnership between management and employees was highlighted by interviewees as being very important to engagement. The interview data also suggested that ‘focused energy’ and ‘alignment with organizational goals’ should further be recognized as key attributes of engagement within the academic literature. Importantly, a number of opportunities to elaborate the Job Demands-Resources model were identified. First, the differential influence of organizational level resources (e.g. senior leadership; organizational climate) versus job level resources emerged. Second, the potential differential influence that challenge versus stressor demands can exert at the organizational level (e.g. large scale organizational change; organizational politics) and at the job level (e.g. role ambiguity; role conflict) emerged. Third, the direct effects of both challenge demands and hindrance demands on work engagement could be usefully and more explicitly acknowledged in the JD-R model. Finally, taking into account the study limitations, we propose future opportunities to extend the integration of the science and the practice of employee engagement.

Mientras que la práctica y la ciencia del engagement laboral continúan recorriendo caminos separados, la ciencia del engagement sigue evolucionando a través de constantes refinamientos aplicados a modelos y medidas existentes. Este estudio cualitativo busca poder mapear el alcance de la separación de la ciencia y la práctica; además de informar el contenido de la ciencia y la práctica del engagement laboral. Los datos obtenidos a partir de un universo de 51 operadores experimentados y gerentes de recursos humanos, pertenecientes a una compañía minera multinacional, revelaron que mientras una considerable sobreposición es aparente en la forma en que los científicos y practicantes ven la naturaleza y las conducciones del engagement laboral, también existen diferencias clave y de énfasis. De manera consistente con investigaciones recientes, la importancia recíproca, o la sociedad igualitaria entre gerentes y empleados, se destacó como algo esencial por parte de los entrevistados en función del engagement. Los datos obtenidos también sugieren que la “energía enfocada” y “la alineación de objetivos organizacionales, deberían ser reconocidos como atributos fundamentales del engagement dentro de la literatura académica. Es de esta forma, se identificaron un número de oportunidades para elaborar un modelo de “Demandas y Recursos Laborales” (Job Demands-Resources model, en inglés). Lo primero en surgir fue la influencia diferencial de los recursos de nivel organizacional (liderazgo experimentado; clima organizacional) versus los recursos de nivel laboral. Lo segundo en presentase fue la influencia potencial diferencial que desafía versus las demandas estresantes que se ejercen a nivel organizacional (cambio organizacional a gran escala, políticas organizacionales) y al nivel laboral (ambigüedad de rol, conflictos de rol). Tercero, los efectos directos de las ordenes complicadas y las demandas obstaculizadoras sobre el engagement laboral...

In vitro susceptibility of Trypanosoma cruzi strains from Santander, Colombia, to hexadecylphosphocholine (miltefosine), nifurtimox and benznidazole

Introduction. The current chemotherapy for Chagas disease is unsatisfactory with only two drugs available for treatment. Research to discover new drugs for Chagas disease is urgent. Hexadecyl-phosphocholine (HPC, miltefosine) has been demonstrated to have in vitro activity against Trypanosoma cruzi parasites, but its activity on different Colombian T. cruzi strains is not known. Objective. To evaluate the in vitro susceptibility of T. cruzi strains isolated from humans and vectors in Santander, Colombia, to miltefosine, nifurtimox and benznidazole. Materials and methods. Eight T. cruzi Colombian strains and three reference strains (Esmeraldo, SilvioX10 and Y) were studied. Drug activities against extracellular epimastigotes and intracellular amastigotes were determined by microscopic counting. The results were expressed as the concentrations that inhibited 50% and 90% growth (IC50 and IC90). Results. For miltefosine a similar range of drug activity was observed against all the Colombian strains, all parasites being more susceptible to miltefosine than to the reference drugs. The intracellular amastigotes were more susceptible to miltefosine (IC50 0.08 to 0.63 ìM and IC90 0.21 to 2.21 ìM) than extracellular forms (IC50 <0.92 to 2.29 ìM and IC90 1.38 to 4.76 ìM). For reference drugs, parasites were more susceptible to nifurtimox than to benznidazole and some differences in activity of benznidazole between T. cruzi strains was observed. Conclusions. The results showed the significant in vitro activity of miltefosine against T. cruzi stages, and the expected results for the reference drugs. Further in vivo studies with miltefosine are planned.

Introducción. Los tratamientos actuales para la enfermedad de Chagas son insatisfactorios y sólo existen dos medicamentos disponibles. La búsqueda de alternativas terapéuticas es prioritaria. La hexadecilfosfocolina (miltefosina) ha mostrado actividad in vitro contra Trypanosoma cruzi. Sin embargo, su actividad en aislamientos de T. cruzi obtenidos en Colombia aún no ha sido reportada. Objetivo. Evaluar la susceptibilidad in vitro a miltefosina, nifurtimox y benznidazole de cepas de T. cruzi aisladas de humanos y vectores en Santander, Colombia. Materiales y métodos. Se evaluó la susceptibilidad de los tres medicamentos en ocho cepas colombianas de T. cruzi y tres cepas de referencia: Esmeraldo, Silvio X10 y Y. La actividad de los compuestos fue determinada en epimastigotes extracelulares y amastigotes intracelulares, por conteo microscópico. Los resultados se expresaron en concentraciones inhibitorias 50 y 90 (CI50 y CI90). Resultados. Para la miltefosina, se observaron rangos similares en la actividad del medicamento entre las cepas colombianas; todos los parásitos fueron más susceptibles a la miltefosina que a los medicamentos de referencia. Los amastigotes intracelulares fueron más sensibles a la miltefosina (CI50, 0,08 a 0,63 µM y CI90, 0,21 a 2,21 µM) que las formas extracelulares (CI50, <0,92 a 2,29 µM y CI90, 1,38 a 4,76 µM). En los medicamentos de referencia, los parásitos fueron más susceptibles al nifurtimox que al benznidazole. Se observaron algunas diferencias en la actividad del benznidazole en las cepas estudiadas de T. cruzi. Conclusiones. Los resultados obtenidos de la actividad in vitro de miltefosina y de los medicamentos de referencia contra aislamientos de T. cruzi son satisfactorios y serán considerados en estudios posteriores in vivo.

Current scenario of drug development for leishmaniasis.

Although three new drugs or drug formulations, liposomal amphotericin B (AmBisome), miltefosine and paromomycin should be available for the treatment of visceral leishmaniasis (VL) within the next year, they all suffer from limitations of either cost, specific toxicities or parenteral administration. As part of research to identify better treatments for VL and cutaneous leishmaniasis (CL), alternative and potentially cheaper formulations of amphotericin B, alklyphosphocholines other than miltefosine and improved formulations of paromomycin for CL have been identified. Other drugs or compounds that have demonstrated activity in experimental rodent models of infection include licochalcone derivatives, quinoline derivatives, bisphosphonates and a maesabalide; further chemistry based upon these leads is warranted. The process for discovery and development of new antileishmanials would also benefit from improved models, for example, transfected parasites, and non invasive methods of measuring parasite load in rodent models of infection.

Prevalence of nutritional deficiencies in Mexican adolescent women with early and late prenatal care

The objective was to evaluate the prevalence of specific nutritional deficiencies in a group of pregnant adolescents according to the gestational age when they started to receive prenatal care. A group of 163 pregnant adolescents that attended the Instituto Nacional de Perinatología (Mexico City) for the first time to receive prenatal care was evaluated. An anthropometrical evaluation was performed and a blood sample taken to determine hemoglobin, ferritin, erythrocyte folate and plasma zinc to all cases. The mean age was 15 years (11 to 17 years). The mean gestational age when starting prenatal care was 27 +/- 7 gestation weeks and most of them tended to have low weight (97 +/- 12 per cent expected weight for height and gestational age). Eight of every ten adolescents had anemia and iron deficiency. Late prenatal care (> or = 25 weeks) was associated with the risk of presenting anemia OR 5.11 (CI 95 per cent 2.4-10.7) iron deficiency (OR 3.5; CI 95 per cent 1.7 to 7.1) and zinc deficiency (OR 2.9; CI 95 per cent 1.1 a 7.6). In relation to folate deficiency, the opposite effect was observed (OR 0.10; CI 95 per cent 0.02 a 0.48). Lack of opportune prenatal care was associated with the presence of iron and zinc depletion. Probably iron deficiency contributes to an erythrocyte folate accumulation.

Cancer incidence and mortality in Antigua/Barbuda

An inquiry into the incidence and mortality of malignant neoplasms in Antigua/Barbuda was undertaken to document the magnitude of the disease. The top ranking cancers diagnosed in 114 males were skin (26.3%), prostate (22.8%) and upper respiratory and alimentary tract (10.5%). In 130 females, the 3 main cancers were breast (23.1%), cervix uteri (22.3%), and skin (15.3%). The main cancers causing death were stomach (22.3%) and prostate (17.8%) in 157 males; and breast (18.2%) and cervix uteri (14.1%) in 149 females. Imprecise documentation, insufficient clinico-pathological correlation and the finding of advanced cancers underscore the need for a cancer registry and cancer society in Antigua/Barbuda.

The cocaine body packer syndrome

This reports documents the medical conditions associated with toxicity following ingestion of cocaine packaged for transportation. Awareness of this syndrome is important in view of the trafficking of illicit drugs in the region

Torsion of the spermatic cord

The clinical features and pathology of four cases of torsion of the spermatic cord treatedm ar Holberton Hospital between December 1987 and January 1988 were reviewed. The lack of prompt clinical diagnosis delayed therapy in all cases, resulting in orchidectomy. The findings re-emphazise the need for early diagosis and surgical exploration of equivocal cases of acute unilateral scrotal pain if salvage rates are to be improved