Schistosomiasis and associated infections

In hospital-based series viral hepatitis B has been frequently described in association with schistosomiasis whilst in field-based studies the association has not been confirmed. The association between schistosomiasis and Salmonella bacteraemia has been well documented. More recently, acute schistosomiasis has been shown to be a facilitating factor in the genesis of pyogenic liver abscesses caused by Staphylococcus aureus. New evidences indicate an interaction between the acquired immunodeficiency syndrome (AIDS) and schistosomiasis. In this paper, data on the association of schistosomiasis with other infections are updated.

Neues aus Diagnostik und Therapie der spinalen Erkrankungen [Novel aspects of diagnostics and therapy of spinal cord diseases].

BACKGROUND: Both non-traumatic and traumatic spinal cord injuries have in common that a relatively minor structural lesion can cause profound sensorimotor and autonomous dysfunction. Besides treating the cause of the spinal cord injury the main goal is to restore lost function as far as possible. AIM: This article provides an overview of current innovative diagnostic (imaging) and therapeutic approaches (neurorehabilitation and neuroregeneration) aiming for recovery of function after non-traumatic and traumatic spinal cord injuries. MATERIAL AND METHODS: An analysis of the current scientific literature regarding imaging, rehabilitation and rehabilitation strategies in spinal cord disease was carried out. RESULTS: Novel magnetic resonance imaging (MRI) based techniques (e.g. diffusion-weighted MRI and functional MRI) allow visualization of structural reorganization and specific neural activity in the spinal cord. Robotics-driven rehabilitative measures provide training of sensorimotor function in a targeted fashion, which can even be continued in the homecare setting. From a preclinical point of view, defined stem cell transplantation approaches allow for the first time robust structural repair of the injured spinal cord. CONCLUSION: Besides well-established neurological and functional scores, MRI techniques offer the unique opportunity to provide robust and reliable "biomarkers" for restorative therapeutic interventions. Function-oriented robotics-based rehabilitative interventions alone or in combination with stem cell based therapies represent promising approaches to achieve substantial functional recovery, which go beyond current rehabilitative treatment efforts.

Role of defensins and cathelicidin LL37 in auto-immune and auto-inflammatory diseases.

Defensins and cathelicidins are anti-microbial peptides (AMPs) that act as natural antibiotics and are part of the innate immune defence in many species. We consider human defensins and LL37, the only human member of the cathelicidin family. In particular, we refer to the human alpha-defensins called human neutrophil peptides (HNP1 through 4), which are produced by neutrophils, HD5 and HD6, mainly expressed in Paneth cells of intestine, the human beta-defensins HBD1, HBD2 and HBD3, synthesized by epithelial cells and LL37, which is located in granulocytes, but is also produced by epithelial cells of the skin, lungs, and gut. In the last years, the study of AMPs activity and regulation has allowed to understand the important role of these peptides not only in the innate defence mechanisms against bacteria, viruses, fungi, but also in the regulation of immune cell activation and migration. Complementary studies have disclosed a role for AMPs in modulating many physiological processes that involve non-immune cells, such as activation of wound healing, angiogenesis, cartilage remodeling. Due to the pleiotropic tasks of these peptides, many of them are now being discovered to contribute to immune pathology of chronic diseases that affect skin, gut, joints; this is supported by many examples of immune-mediated pathologies in which their expression is disregulated. In this article we review the current literature that suggests a role for human defensins and LL37 in pathogenic mechanisms of several chronic diseases that are considered of auto-immune or auto-inflammatory origin.

Contribution to the sand fly fauna (Diptera: Phlebotominae) of Rio Grande do Sul, Brazil and Leishmania (Viannia) infections

American cutaneous leishmaniasis (ACL) is endemic in the State of Rio Grande do Sul, Brazil. As reports of nearby hospitals suggest, the Parque Estadual do Turvo seems to serve as a source for the disease. During three months from November 1996 to February 1997 we collected, in this park, 2,228 sandflies (10 Lutzomyia species and 2 6species). We applied the polymerase chain reaction to 920 females which belong to the following species: Lutzomyia migonei, Lu. pessoai, Lu. fischeri, Lu. misionensis, Lu. lanei, Lu. neivai, Lu. shannoni, and Lu. monticola, in an attempt to verify natural infection by Leishmania (Viannia), the causative agent of ACL. Le. (Viannia) infections were demonstrated by DNA amplification from two Lu. pessoai and one Lu. misionensis female. Lu. pessoai have been found with leptomonas in the gut believed to be Le. (V.) braziliensis in other endemic areas of northeastern and southeastern Brazil. However, Lu. misionensis has never been found carrying a natural infection of Le. (Viannia).

Bloodmeal microfilariae density and the uptake and establishment of Wuchereria bancrofti infections in Culex quinquefasciatus and Aedes aegypti

The relationship between ingestion of microfilariae (mf), production of infective larvae (L3) and mf density in human blood has been suggested as an important determinant in the transmission dynamics of lymphatic filariasis. Here we assess the role of these factors in determining the competence of a natural vector Culex quinquefasciatus and a non vector Aedes aegypti to transmit Wuchereria bancrofti. Mosquitoes were infected via a membrane feeding procedure. Both mosquito species ingested more than the expected number of microfilariae (concentrating factor was 1.28 and 1.81 for Cx. quinquefasciatus and Ae. aegypti, respectively) but Cx. quinquefasciatus ingested around twice as many mf as Ae. aegypti because its larger blood meal size. Ae. aegypti showed a faster mf migration capacity compared to Cx. quinquefasciatus but did not allow parasite maturation under our experimental conditions. Similar proportions of melanized parasites were observed in Ae. aegypti (2.4%) and Cx. quinquefasciatus (2.1%). However, no relationship between rate of infection and melanization was observed. We conclude that in these conditions physiological factors governing parasite development in the thorax may be more important in limiting vectorial competence than the density of mf ingested.

Infections by Helminth Parasites in "Puyenes", Galaxias maculatus (Galaxiidae, Salmoniformes), from Southern Argentina with special reference to Tylodelphys barilochensis (Digenea, Platyhelminthes)

The occurrence of Tylodelphys barilochensis, Acanthostomoides apophalliformis, Contracaecum sp. and Camallanus corderoi infecting Galaxias maculatus ("puyenes") was quantified for the first time in Lake Nahuel Huapi, southern Argentina. T. barilochensis was recorded in this lake for the first time. The role of G. maculatus population in transmission of parasites to the salmonids is more important for Contracaecum sp. (prevalence 14-34%) and A. apophalliformis (prevalence 30-54%) than for C. corderoi (prevalence 6-8%). The absence of Diphyllobothrium spp. in samples shows that the G. maculatus population does not play any role in the life cycles of these important zoonotic parasites. The sex of the host had no effect on T. barilochensis abundance. Statistical differences in T. barilochensis abundance between "puyenes" of the same size class between sampling stations and positive correlation between prevalence of infected snails and T. barilochensis abundance in fish suggest that different stocks have been sampled. Factors influencing T. barilochensis abundance are discussed.

Syndrome métabolique, diabète sucré et vulnérabilité: une approche "syndémique" de la maladie chronique [Metabolic syndrome, diabetes mellitus and vulnerability: a syndemic approach of chronic diseases].

The pandemic metabolic syndrome is generally attributed to our lifestyle. The current therapeutic strategies are centered on the behavioral changes and pharmacotherapy. A deeply analysis reveals the importance of the socio-cultural determinants with a "dose-responses effect according to the socio-economic level. The "syndemic" theory, which puts at the same level the socio-cultural environment, the behaviors and biomedecine, suggests a more holistic approach. This theory suggests introducing other partners of care, such cultural-mediators and welfare workers trained in the care, to have finally an approach centered on the roots of the causes. The healthcare networks centered on the management of the costs of health should not forget the socio-cultural dimension, unless wanting to select the good cases.

Prevention of transfusional Trypanosoma cruzi infection in Latin America

Trypanosoma cruzi is a protozoan infection widely spread in Latin America, from Mexico in the north to Argentina and Chile in the south. The second most important way of acquiring the infection is by blood transfusion. Even if most countries of Latin America have law/decree/norms, that make mandatory the screening of blood donors for infectious diseases, including T. cruzi (El Salvador and Nicaragua do not have laws on the subject), there is usually no enforcement or it is very lax. Analysis of published serologic surveys of T. cruzi antibodies in blood donors done in 1993, indicating the number of donors and screening coverage for T. cruzi in ten countries of Central and South America indicated that the probability of receiving a potentially infected transfusion unit in each country varied from 1,096 per 10,000 transfusions in Bolivia, the highest, to 13.02 or 13.86 per 10,000 transfusions in Honduras and Venezuela respectively, where screening coverage was 100%. On the other hand the probability of transmitting a T. cruzi infected unit was 219/10,000 in Bolivia, 24/10,000 in Colombia, 17/10,000 in El Salvador, and around 2-12/10,000 for the seven other countries. Infectivity risks defined as the likelihood of being infected when receiving an infected transfusion unit were assumed to be 20% for T. cruzi. Based on this, estimates of the absolute number of infections induced by transfusion indicated that they were 832, 236, and 875 in Bolivia, Chile and Colombia respectively. In all the other countries varied from seven in Honduras to 85 in El Salvador. Since 1993, the situation has improved. At that time only Honduras and Venezuela screened 100% of donors, while seven countries, Argentina, Colombia, El Salvador, Honduras, Paraguay, Uruguay and Venezuela, did the same in 1996. In Central America, without information from Guatemala, the screening of donors for T. cruzi prevented the transfusion of 1,481 infected units and the potential infection of 300 individuals in 1996. In the same year, in seven countries of South America, the screening prevented the transfusion of 36,017 infected units and 7, 201 potential cases of transfusional infection.

Establishment and characterization of a new continuous cell line from Lutzomyia longipalpis (Diptera: Psychodidae) and its susceptibility to infections with arboviruses and Leishmania chagasi

Embryonic tissue explants of the sand fly Lutzomyia longipalpis (Lutz & Neiva 1912) the main vector of Leishmania chagasi (Cunha and Chagas), were used to obtain a continuous cell line (Lulo). The tissues were seeded in MM/VP12 medium and these were incubated at 28ºC. The first subculture was obtained 45 days after explanting and 96 passages have been made to date. Lulo is composed of epithelioid cells, showed a 0.04 generations/hour exponential growth rate and population doubling time at 24.7 h. The cell line isoenzymatic profiles were determined by using PGI, PGM, MPI and 6-PGDH systems, coinciding with patterns obtained from the same species and colony's pupae and adults. The species karyotype characteristics were recognized (2n = 8), in which pair 1 is subtelocentric and pairs 2, 3 and 4 are metacentric. Lulo was free from bacterial, fungal, mycoplasmic and viral infection. Susceptibility to five arbovirus was determined, the same as Lulo interaction with Leishmania promastigotes.