Trypanosoma cruzi: Maintenance in Culture Modify Gene and Antigenic Expression of Metacyclic Trypomastigotes

In this study we examined whether the maintenance of Trypanosoma cruzi by long-time in axenic culture produces changes in gene expression and antigenic profiles. The studies were made with a Dm30L-clone from a low-virulent strain and a non-cloned virulent EP-strain of T. cruzi. Both parasites were maintained, for at least seven years, by successive alternate passage triatomine/mouse (triatomine condition), or by serial passage in axenic medium (culture condition). The comparison of the [35S]methionine metabolic labeling products of virulent and non-virulent parasites by 2D-SDS-PAGE, clearly indicates that the expression of metacyclic trypomastigotes (but not of epimastigotes) proteins have been altered by laboratory maintenance conditions. Western blot analysis of EP and Dm30L-epimastigotes using a serum anti-epimastigotes revealed that although most of antigens are conserved, four antigens are characteristics of triatomine condition parasites and three other are characteristics of culture condition parasites. Anti-metacyclics serum revealed significative differences in EP- and Dm30L-metacyclic trypomastigotes from triatomine condition. However, avirulent metacyclic forms were antigenically very similar. These results suggest that besides a possible selection of avirulent subpopulation from T. cruzi strains genetically heterogeneous when maintained by long time in axenic culture, changes in virulence might be due to post-translational modifications of the antigens induced by the absence of the natural alternability (vertebrate-invertebrate) in the life-cycle of T. cruzi

Inflammation-induced alteration of astrocyte mitochondrial dynamics requires autophagy for mitochondrial network maintenance.

Accumulating evidence suggests that changes in the metabolic signature of astrocytes underlie their response to neuroinflammation, but how proinflammatory stimuli induce these changes is poorly understood. By monitoring astrocytes following acute cortical injury, we identified a differential and region-specific remodeling of their mitochondrial network: while astrocytes within the penumbra of the lesion undergo mitochondrial elongation, those located in the core-the area invaded by proinflammatory cells-experience transient mitochondrial fragmentation. In brain slices, proinflammatory stimuli reproduced localized changes in mitochondrial dynamics, favoring fission over fusion. This effect was triggered by Drp1 phosphorylation and ultimately resulted in reduced respiratory capacity. Furthermore, maintenance of the mitochondrial architecture critically depended on the induction of autophagy. Deletion of Atg7, required for autophagosome formation, prevented the reestablishment of tubular mitochondria, leading to marked reactive oxygen species accumulation and cell death. Thus, our data reveal autophagy to be essential for regenerating astrocyte mitochondrial networks during inflammation.

Experimental infection of canine peritoneal macrophages with visceral and dermotropic Leishmania strains

A study was carried out using macrophages cultured from the peritoneal exudate of dogs infected in vitro with three species of Leishmania: L. (L.) chagasi, L. (Viannia) braziliensis and L. (L.) amazonensis with the aim of investigating the growth kinetics and infectivity of these species in the host cell. Results were expressed as the percentage of macrophages infected measured at 24 hr intervals over six days in RPMI - 1640 culture medium at a temperature of 34-35oC. The findings open the possibility of using canine peritoneal cells as a model for the screenning of leishmanicide drugs and to study the pathogenesis of these species.

Cutaneous cancer stem cell maintenance is dependent on beta-catenin signalling.

Continuous turnover of epithelia is ensured by the extensive self-renewal capacity of tissue-specific stem cells. Similarly, epithelial tumour maintenance relies on cancer stem cells (CSCs), which co-opt stem cell properties. For most tumours, the cellular origin of these CSCs and regulatory pathways essential for sustaining stemness have not been identified. In murine skin, follicular morphogenesis is driven by bulge stem cells that specifically express CD34. Here we identify a population of cells in early epidermal tumours characterized by phenotypic and functional similarities to normal bulge skin stem cells. This population contains CSCs, which are the only cells with tumour initiation properties. Transplants derived from these CSCs preserve the hierarchical organization of the primary tumour. We describe beta-catenin signalling as being essential in sustaining the CSC phenotype. Ablation of the beta-catenin gene results in the loss of CSCs and complete tumour regression. In addition, we provide evidence for the involvement of increased beta-catenin signalling in malignant human squamous cell carcinomas. Because Wnt/beta-catenin signalling is not essential for normal epidermal homeostasis, such a mechanistic difference may thus be targeted to eliminate CSCs and consequently eradicate squamous cell carcinomas.

Appropriateness of methadone maintenance treatment for opiate addiction: evaluation by an expert panel.

With some 30,000 dependent persons, opiate addiction constitutes a major public health problem in Switzerland. The Swiss Federal Office of Public Health (FOPH) has long played a leading role in the prevention and treatment of opiate addiction and in research on effective means of containing the epidemic of opiate addiction and its consequences. Major milestones on that path have been the successive "Methadone reports" published by that Office and providing guidance on the care of opiate addiction with substitution treatment. In view of updating the recommendations for the appropriateness of substitution treatment for opiate addiction, in particular for the prescription of methadone, the FOPH commissioned a multi-component project involving the following elements. A survey of current attitudes and practices in Switzerland related to opiate substitution treatment Review of Swiss literature on methadone substitution treatment Review of international literature on methadone substitution treatment National Methadone Substitution Conference Multidisciplinary expert panel to evaluate the appropriateness of substitution treatment. The present report documents the process and summarises the results of the latter element above. The RAND appropriateness method (RAM) was used to distil from literature-based evidence and systematically formulated expert opinion, areas where consensus exist on the appropriateness (or inappropriateness) of methadone maintenance treatment (MMT) and areas where disagreement or uncertainty persist and which should be further pursued. The major areas which were addressed by this report are Initial assessment of candidates for MMT Appropriate settings for initiation of MMT (general and special cases) Appropriateness of methadone supportive therapy Co-treatments and accompanying measures Dosage schedules and pharmacokinetic testing Withdrawal from MMT Miscellaneous questions Appropriateness of other (non-methadone) substitution treatment Summary statements for each of the above categories are derived from the panel meeting and presented in the report. In the "first round", agreement was observed for 31% of the 553 theoretical scenarios evaluated. The "second round" rating, following discussion of divergent ratings, resulted in a much higher agreement among panellists, reaching 53% of the 537 scenarios. Frank disagreement was encountered for 7% of all scenarios. Overall 49% of the clinical situations (scenarios) presented were considered appropriate. The areas where at least 50% of the situations were considered appropriate were "initial assessment of candidates for MMT", the "appropriate settings for initiation of MMT", the "appropriate settings for methadone supportive treatment" and "Appropriateness of other (non-methadone) substitution treatment". The area where there was the least consensus on appropriateness concerned "appropriateness of withdrawal from MMT" (6%). The report discusses the implications and limitations of the panel results and provides recommendations for the dissemination, application, and future use of the criteria for the appropriateness of MMT. The RAND Appropriateness Method proved to be an accepted and appreciated method to assess the appropriateness of methadone maintenance treatment for opiate addicts. In the next step, the results of the expert panel process must now be combined with those of the Swiss and international literature reviews and the survey of current attitudes and practices in Switzerland, to be synthesized into formal practice guidelines. Such guidelines should be disseminated to all concerned, promoted, used and rigorously evaluated for compliance and outcome.

Candidiasis Peritoneal: prevalença i factors de risc. Estudi preliminar

Introducció: Un cultiu positiu de líquid peritoneal per a Càndida spp amb clínica associada, és diagnòstic de Candidiasis Peritoneal (CP). Objetius: L’objectiu primari és coneixer la prevalença de CP. Com objectius secundaris coneixer els possibles factors de risc. Tipus d’estudi: Prospectiu, observacional. Mètodes: S’agafa una mostra de 74 pacients amb diagnòstic de peritonitis (2007-2010). Durant la cirugía s’aspira líquid peritoneal lliure i és conrea. Resultats i conclusions: La prevalença va ser del 17.6% (46.15% C. albicans). L’ afectació del tracte gastro-intestinal-superior (OR 6.554) i l’aparició de fallada cardio-vascular durant la cirugia (OR 5.827), són factors de risc per a desenvolupar-la. És estudi preliminar.

Aspects of the Maintenance of the Life Cycle of Fasciola hepatica in Lymnaea columella in Minas Gerais, Brazil

Fascioliasis is a parasitic disease of domestic ruminants that occurs worldwide. The lymnaeid intermediate hosts of Fasciola hepatica include Lymnaea columella, which is widely distributed in Brazil. A colony of L. columella from Belo Horizonte, MG, was reared in our laboratory to be used in studies of the F. hepatica life cycle, the intermediate host-parasite relationship and development of an anti-helminthic vaccine. In the first experiment 1,180 snails were exposed to miracidia of F. hepatica eggs removed from the biliary tracts of cattle from the State of Rio Grande do Sul. In the second and third experiments the snails were exposed to miracidia that had emerged from F. hepatica eggs from Uruguay, maintained in rabbits. The rates of infection in the first, second and third experiments were 0, 42.1 and 0% respectively. Over 15,806 metacercariae were obtained and stored at 4ºC. Four rabbits weighing 1.5 kg each were infected with 32-44 metacercariae and two with 200. Three rabbits begin to eliminate eggs of the parasite in the feces from 84 days after infection onwards. The biological cycle of F. hepatica in L. columella and the rabbit was completed within 124 days.

Methadone maintenance treatment (MMT) in general practice or in specialized centers: profile of patients in the Swiss Canton of Vaud.

We studied profile of patients (n=1782) treated in specialized centers and general practice (GP) enrolled in methadone maintenance treatment (MMT) programs during 2001 in the Swiss Canton of Vaud. We found that GPs treated the majority of patients (76%). Specialized centers treated a higher proportion of patients with uncontrolled intravenous use of cocaine and heroin, and prescribed neuroleptics as concomitant medication three times more frequently than GPs. Patients treated in specialized centers were more likely to undergo screening for HIV, HBV, HCV, and receive complete HBV immunization. In conclusion, specialized centers are more likely to treat severely addicted patients and patients with a poor global assessment (physical, psychiatric, and social).

Ultrafiltració insuficient en pacients en diàlisi peritoneal

Alguns pacients que realitzen diàlisi peritoneal (DP) presenten sobrecàrrega de volum sense fallada d’ultrafiltració (UF) i precisen per controlar-ho augmentar la concentració d’agents osmòtics dels recanvis peritoneals. L’objectiu de l’estudi és conèixer les característiques clíniques i relacionar la UF amb la càrrega de glucosa administrada. Estudi observacional transversal de 31 pacient en DP. S’han enregistrat dades clíniques, analítiques, solucions administrades, osmolaritat i ultrafiltració de cada recanvi. Concloem que els pacients amb ultrafiltració insuficient tenen menor diüresi, menor funció renal residual i pitjor estat nutricional. No hem trobat diferències en els índex que relacionen ultrafiltració amb càrrega osmolar en aquest pacients.

Augmented epithelial multidrug resistance-associated protein 4 expression in peritoneal endometriosis: regulation by lipoxin A(4).

OBJECTIVE: To compare the expression of the prostaglandin (PG) E(2) transporter multidrug resistance-associated protein 4 (MRP4) in eutopic and ectopic endometrial tissue from endometriosis patients with that of control subjects and to examine whether MRP4 is regulated by the antiinflammatory lipid lipoxin A(4) (LXA(4)) in endometriotic epithelial cells. DESIGN: Molecular analysis in human samples and a cell line. SETTING: Two university hospitals and a private clinic. PATIENT(S): A total of 59 endometriosis patients and 32 age- and body mass index-matched control subjects undergoing laparoscopy or hysterectomy. INTERVENTION(S): Normal, eutopic, and ectopic endometrial biopsies as well as peritoneal fluid were obtained during surgery performed during the proliferative phase of the menstrual cycle. 12Z endometriotic epithelial cells were used for in vitro mechanistic studies. MAIN OUTCOME MEASURE(S): Tissue MRP4 mRNA levels were quantified by quantitative reverse-transcription polymerase chain reaction (qRT-PCR), and localization was analyzed with the use of immunohistochemistry. Cellular MRP4 mRNA and protein were quantified by qRT-PCR and Western blot, respectively. PGE(2) was measured in peritoneal fluid and cell supernatants using an enzyme immunoassay (EIA). RESULT(S): MRP4 was expressed in eutopic and ectopic endometrium, where it was overexpressed in peritoneal lesions and localized in the cytoplasm of glandular epithelial cells. LXA(4) attenuated MRP4 mRNA and protein levels in endometriotic epithelial cells in a dose-dependent manner, while not affecting the expression of enzymes involved in PGE(2) metabolism. Investigations employing receptor antagonists and small interfering RNA revealed that this occurred through estrogen receptor α. Accordingly, LXA(4) treatment inhibited extracellular PGE(2) release. CONCLUSION(S): We report for the first time that MRP4 is expressed in human endometrium, elevated in peritoneal endometriosis, and modulated by LXA(4) in endometriotic epithelial cells.

Persistent human parvovirus B19 infection in children under maintenance chemotherapy for acute lymphocytic leukemia.

OBJECTIVE: To report on B19 infection management and chemotherapy schedule consequences in five children treated for acute lymphocytic leukemia (ALL). PATIENTS AND METHODS: Between May 2001 and February 2002, five patients between 4 and 12 years of age, receiving maintenance chemotherapy for ALL, presented with symptoms suggesting B19 infection (pallor, fatigue, petechiae and pancytopenia in four patients; generalized rash in two patients; acute hepatitis in one patient). Qualitative polymerase chain reaction (PCR) on peripheral blood was used for diagnosis and follow-up of infection; quantitative PCR was used for viral load measurement. Intravenous nonspecific high-dose immunoglobulin therapy was administered until PCR was negative. RESULTS: Qualitative B19 DNA was found in the peripheral blood of all patients, confirming the infection. Viral load at diagnosis ranged from 10 to 10 particles/mL blood. B19 DNA was detectable in four patients at 45, 21, 40, and 44 weeks, respectively. Chemotherapy was delayed in all patients. No clear benefit of intravenous immunoglobulin was noted. CONCLUSIONS: Infection with B19 is rarely reported in patients with ALL, but it should be suspected when unexplained pancytopenia occurs during chemotherapy. Persistent B19 infection remains a challenge in the management of patients receiving maintenance chemotherapy for ALL, as no specific therapy such as a specific immunoglobulin or vaccine exists. The role of viral load measurement needs to be established in terms of its use in follow-up and evaluation of the therapeutic response.

Effect of angiotensin II and losartan on the phagocytic activity of peritoneal macrophages from Balb/C mice

Angiotensin II (AII), a product of rennin-angiotensin system, exerts an important role on the function of immune system cells. In this study, the effect of AII on the phagocytic activity of mouse peritoneal macrophages was assessed. Mice peritoneal macrophages were cultured for 48 h and the influence of different concentrations of AII (10-14 to 10-7 M) and/or losartan, 10-16 to 10-6 M), an AT1 angiotensin receptor antagonist, on phagocytic activity and superoxide anion production was determined. Dimethylthiazoldiphenyltetrazolium bromide reduction and the nucleic acid content were used to assess the cytotoxicity of losartan. A stimulatory effect on phagocytic activity (P < 0.05) was observed with 10-13 M and 10-12 M AII concentrations. The addition of losartan (up to10-14 M) to the cell cultures blocked (P < 0.001) the phagocytosis indicating the involvement of AT1 receptors. In contrast, superoxide anion production was not affected by AII or losartan. The existence of AT1 and AT2 receptors in peritoneal macrophages was demonstrated by immunofluorescence microscopy. These results support the hypothesis that AII receptors can modulate murine macrophage activity and phagocytosis, and suggest that AII may have a therapeutic role as an immunomodulatory agent in modifying the host resistance to infection.

Assessing The Effectiveness of HACCP Implementation and Maintenance

The primary objective of the study was to assess the effectiveness with which HACCP (Hazard Analysis Critical Control Point) has been implemented and maintained in food manufacturing plants in Northern Ireland and the Republic of Ireland. Where inadequacies in implementation or maintenance of the HACCP system were highlighted the study sought to identify the contributory factors, with a view to making specific recommendations to overcome these limitations.

Role of secretory IgA in infection and maintenance of homeostasis.

An important activity of mucosal surfaces is the production of antibodies (Abs) referred to as secretory immunoglobulin A (SIgA) that serve as a first line of defense to repel pathogenic microorganisms and provide a finely tuned balance to guarantee controlled survival of essential commensal bacteria. By excluding bacteria from the epithelial cell, SIgA participates in the cross-talk between the host and its intestinal content, ensuring appropriate homeostasis under normal conditions. Besides the classical view of immune exclusion function, SIgA Abs exhibit the striking feature to adhere to gastrointestinal M cells residing in the follicle-associated epithelium in organized structures called Peyer's patches. Selective binding of SIgA results in transport across the microfold (M) cells, a process that facilitates the association of the Ab with dendritic cells (DCs) located in the underlying subepithelial dome region of Peyer's patches. Limited entry of free SIgA and SIgA-coated bacteria via this pathway is crucial to the modulation of local immune responses in an environment that limits the onset of pro-inflammatory circuits. Such a mechanism would ensure homeostasis by allowing antigen recognition under neutralized conditions and by avoiding tissue dissemination, two features that endow SIgA with non-inflammatory properties in the mucosal environment.