Infection of Anopheles gambiae mosquitoes with entomopathogenic fungi: effect of host age and blood-feeding status

Physiological characteristics of insects can influence their susceptibility to fungal infection of which age and nutritional status are among the most important. An understanding of host–pathogen interaction with respect to these physiological characteristics of the host is essential if we are to develop fungal formulations capable of reducing malaria transmission under field conditions. Here, two independent bioassays were conducted to study the effect of age and blood-feeding status on fungal infection and survival of Anopheles gambiae s.s. Giles. Mosquitoes were exposed to 2 × 10¹⁰ conidia m⁻² of oil-formulated Metarhizium anisopliae ICIPE-30 and of Beauveria bassiana I93-825, respectively, and their survival was monitored daily. Three age groups of mosquitoes were exposed, 2–4, 5–8, and 9–12 days since emergence. Five groups of different feeding status were exposed: non-blood-fed, 3, 12, 36, and 72 h post-blood feeding. Fungal infection reduced the survival of mosquitoes regardless of their age and blood-feeding status. Although older mosquitoes died relatively earlier than younger ones, age did not tend to affect mosquito susceptibility to fungal infection. Non-blood-fed mosquitoes were more susceptible to fungus infection compared to all categories of blood-fed mosquitoes, except for those exposed to B. bassiana 72 h post-blood feeding. In conclusion, formulations of M. anisopliae and B. bassiana can equally affect mosquitoes of different age classes, with them being relatively more susceptible to fungus infection when non-blood-fed.     

Papillary tumor of the pineal region: report of a rapidly progressive tumor with possible multicentric origin

Papillary tumor of the pineal region (PTPR) is an uncommon tumor recently added to the WHO classification of CNS tumors. We report a case of PTPR in a young boy that was noteworthy for early CSF dissemination and relentless progression. In spite of intensive chemotherapy and comprehensive radiotherapy, the boy died. The neuroimaging appearance is unique with possible multicentric origin of the tumor and intense uptake of ¹¹¹In-DTPA-pentetreotide.     

Leiomyosarcoma of the epididymis: 2 cases and review of the literature

Paratesticular leiomyosarcomas are rare. We report two cases of leiomyosarcoma of the epididymis diagnosed and treated in a regional community hospital in Canada in 2009 and 2010. Both patients were males of ages 58 and 75, respectively. They presented with painless masses which, on ultrasonography, appeared to be solid masses demonstrating blood flow. Each patient underwent trans-scrotal resection of the affected epididymis. Pathological examination of trans-scrotal epididymectomy specimens confirmed the diagnosis of high-grade leiomyosarcoma. Leiomyosarcoma is an important differential diagnosis for paratesticular masses in the elderly male; the primary treatment is radical inguinal orchiectomy with high ligation of the spermatic cord.     

Mutant Mouse Models: Genotype-Phenotype Relationships to Negative Symptoms in Schizophrenia

Negative symptoms encompass diminution in emotional expression and motivation, some of which relate to human attributes that may not be accessible readily in animals. Additionally, their refractoriness to treatment precludes therapeutic validation of putative models. This review considers critically the application of mutant mouse models to the study of the pathobiology of negative symptoms. It focuses on 4 main approaches: genes related to the pathobiology of schizophrenia, genes associated with risk for schizophrenia, neurodevelopmental-synaptic genes, and variant approaches from other areas of neurobiology. Despite rapid advances over the past several years, it is clear that we continue to face substantive challenges in applying mutant models to better understand the pathobiology of negative symptoms: the majority of evidence relates to impairments in social behavior, with only limited data relating to anhedonia and negligible data concerning avolition and other features; even for the most widely examined feature, social behavior, studies have used diverse assessments thereof; modelling must proceed in cognizance of increasing evidence that genes and pathobiologies implicated in schizophrenia overlap with other psychotic disorders, particularly bipolar disorder. Despite the caveats and challenges, several mutant lines evidence a phenotype for at least one index of social behavior. Though this may suggest superficially some shared relationship to negative symptoms, it is not yet possible to specify either the scope or the pathobiology of that relationship for any given gene. The breadth and depth of ongoing studies in mutants hold the prospect of addressing these shortcomings.     

Mechanical Effects of Rear-Wheel Camber on Wheelchairs

Giving the rear wheels of manually propelled wheelchairs negative camber (by angling them such that the bottoms of the wheels are farther apart than the tops) has become increasingly popular, especially among active users. This study's purpose was to evaluate how changing camber affects a wheelchair's mechanics and the extent of these changes. Using a representative wheelchair occupied by an anthropomorphic dummy, we altered the camber from +15° to ?15° and measured the effects on nine selected variables. In addition to increasing the wheelchair's track width, negative camber increases the wheelchair's wheelbase and decreases the height of the frame. With negative camber, the center of gravity (CG) of the occupied wheelchair moves backwards. Negative camber causes a backwards tilt of the frame which, in turn, causes toe-out of the rear wheels, a positive caster-inclination angle and an increase in the caster-trail distance. It is apparent that a change in one component of a wheelchair can affect many others, which should be taken into consideration and, where appropriate, compensated for when changing the camber of the wheelchair.     

Push, Pull, and Reverse: Self-Interest, Responsibility, and the Global Health Care Worker Shortage

The world is suffering from a dearth of health care workers, and sub-Saharan Africa, an area of great need, is experiencing the worst shortage. Developed countries are making the problem worse by luring health care workers away from the countries that need them most, while developing countries do not have the resources to stem the flow or even replace those lost. Postmodern philosopher Emmanuel Levinas offers a unique ethical framework that is helpful in assessing both the irresponsibility inherent in the current global health care situation and the responsibility and obligation held by the stakeholders involved in this global crisis. Drawing on Levinas’ exploration of individual freedom and self-pursuit, infinite responsibility for the Other, and the potential emergence of a just community, we demonstrate its effectiveness in explaining the health care worker crisis, and we argue in favor of a variety of policy and development assistance measures that are grounded in an orientation of non-indifference toward Others.