Intestinal absorption of macromolecules during viral enteritis: an experimental study on rotavirus-infected conventional and germ-free mice.

Epithelial transport and degradation of horseradish peroxidase (HRP), a macromolecular tracer, was studied in conventional and germ-free suckling mice following an experimental infection with rotavirus. Conventional and germ-free mice developed diarrhea from days 2 to 8 postinfection (pi), with growth failure. In mucosal homogenates, infectious virus detected by immunofluorescence on MA 104 cells was present from day 2 through day 8 pi in germ-free mice, but persisted longer (day 13 pi) in conventional mice. Only mild histological lesions were observed during diarrhea, but obvious macrovacuolation of epithelial cells and increased cellular density occurred during the convalescence period (days 9 to 13 pi). Intact and degraded HRP fluxes from mucosa to serosa were measured in vitro on segments of jejunum mounted in Ussing chambers. Both groups of mice developed increased HRP permeability during the experimental period, but at different times after inoculation: during the diarrheal period (days 2 and 3 pi) conventional mouse epithelium absorbed five times more HRP than noninfected controls and during the convalescence period (days 9 to 13 pi) HRP absorption in germ-free mice rose 10-fold as compared to its level before infection. In both cases, this increase in HRP permeability was entirely due to an increase in intact HRP absorption, probably via a transcellular route, and occurred without any alteration in degraded HRP transport. These results indicate that in mice, rotavirus infection causes a transient rise in gut permeability to undegraded proteins. The intestinal microflora seems to affect the timing, magnitude, and duration of this increased permeability

Ecology of Phlebotomine Sand Flies in the Rural Community of Mont Rolland (Thiès Region, Senegal): Area of Transmission of Canine Leishmaniasis

BACKGROUND: Different epidemiological studies previously indicated that canine leishmaniasis is present in the region of Thiès (Senegal). However, the risks to human health, the transmission cycle and particularly the implicated vectors are unknown. METHODOLOGY/PRINCIPAL FINDINGS: To improve our knowledge on the population of phlebotomine sand flies and the potential vectors of canine leishmaniasis, sand flies were collected using sticky traps, light traps and indoor spraying method using pyrethroid insecticides in 16 villages of the rural community of Mont Rolland (Thiès region) between March and July 2005. The 3788 phlebotomine sand flies we collected (2044 males, 1744 females) were distributed among 9 species of which 2 belonged to the genus Phlebotomus: P. duboscqi (vector of cutaneous leishmaniasis in Senegal) and P. rodhaini. The other species belonged to the genus Sergentomyia: S. adleri, S. clydei, S. antennata, S. buxtoni, S. dubia, S. schwetzi and S. magna. The number of individuals and the species composition differed according to the type of trap, suggesting variable, species-related degrees of endophily or exophily. The two species of the genus Phlebotomus were markedly under-represented in comparison to the species of the genus Sergentomyia. This study also shows a heterogeneous spatial distribution within the rural community that could be explained by the different ecosystems and particularly the soil characteristics of this community. Finally, the presence of the S. dubia species appeared to be significantly associated with canine leishmaniasis seroprevalence in dogs. CONCLUSIONS/SIGNIFICANCE: Our data allow us to hypothesize that the species of the genus Sergentomyia and particularly the species S. dubia and S. schwetzi might be capable of transmitting canine leishmaniasis. These results challenge the dogma that leishmaniasis is exclusively transmitted by species of the genus Phlebotomus in the Old World. This hypothesis should be more thoroughly evaluated

Low-cost liquid medium for in vitro cultivation of Leishmania parasites in low-income countries

Background: Cutaneous Leishmaniasis (CL) induced by Leishmania aethiopica has two clinical manifestations: ulcerating, self-healing CL and non-ulcerating, non-healing CL. The grossly disfiguring multiple nodules on the face and exterior surface of limbs during non-ulcerative CL are sometimes misdiagnosed as other skin infections. Thus the need for definitive and prompt laboratory diagnosis will be required. Identifying Leishmania parasite by culture method is considered as a definitive method for initiation of treatment and as an effective component of leishmaniasis control methods. Recently the involvement of Fas (CD95) and Tumor Necrosis Factor (TNF) Related Apoptosis Inducing Ligand (TRAIL) induced apoptotic pathways were proposed to be involved in tissue destruction and ulceration during L. major induced CL. Aims: 1) to develop an alternative culture media that could minimize the cost for culturing Leishmania from patient lesions. 2) to investigate if the expression of FasL and TRAIL differs in ulcerating and non- ulcerative CL. Methods: GALF-1 media was formulated in our lab and compared to RPMI 1640 medium and conventional Locke s semi solid media (LSSM) which is one of the modifications of Novy-MacNeal-Nicolle (NNN) culture media. Amastigotes transformation, cryopreservation, recovery of parasites, cost and mass cultivation were analysed. Expression of Fas ligand (FasL), TRAIL and apoptosis were assessed by immunohistology in human skin biopsies from L. aethiopica induced ulcerative or non-ulcerative CL. FasL and TRAIL blocking experiments were performed in a murine model of CL. Results and discussion: GALF-1 is cheap and its ingredients available in a low income country such as Ethiopia. GALF-1 was able to transform amastigotes from Ethiopian patients samples and could be used to cultivate promastigotes in large quantities. Cost analysis showed 80% to 95 % decreased costs as compared to conventional media. Promastigotes cultured with GALF-1 could be cryopreserved in liquid nitrogen with comparable re-culture potential to conventional media. Affordability of diagnostic assays is a key issue for resource poor countries and the possibility to cut the cost of the efficient culture method for diagnosis through the use of inexpensive local formulated reagents could improve the diagnosis of leishmaniasis in low income endemic countries. More FasL expressing cells were detected in dermis of ulcerative CL as compared to non-ulcerative CL and controls. TRAIL expression was higher in ulcerative CL as compared to non-ulcerative CL and controls in both epidermis and dermis. Increased dermal expression of FasL and TRAIL was associated with ulcer formation during CL. This correlated with an inhibition of the ulcerative process in a murine CL model during FasL and TRAIL neutralisation.The mechanisms of the involvement of FasL and TRAIL in ulceration was not elucidated and putative reason(s) for the difference in dysregulation of apoptosis are discussed

Patients' and Practitioners' Views of Knee Osteoarthritis and Its Management: A Qualitative Interview Study

PURPOSE: To identify the views of patients and care providers regarding the management of knee osteoarthritis (OA) and to reveal potential obstacles to improving health care strategies. METHODS: We performed a qualitative study based on semi-structured interviews of a stratified sample of 81 patients (59 women) and 29 practitioners (8 women, 11 general practitioners [GPs], 6 rheumatologists, 4 orthopedic surgeons, and 8 [4 GPs] delivering alternative medicine). RESULTS: Two main domains of patient views were identified: one about the patient-physician relationship and the other about treatments. Patients feel that their complaints are not taken seriously. They also feel that practitioners act as technicians, paying more attention to the knee than to the individual, and they consider that not enough time is spent on information and counseling. They have negative perceptions of drugs and a feeling of medical uncertainty about OA, which leads to less compliance with treatment and a switch to alternative medicine. Patients believe that knee OA is an inevitable illness associated with age, that not much can be done to modify its evolution, that treatments are of little help, and that practitioners have not much to propose. They express unrealistic fears about the impact of knee OA on daily and social life. Practitioners' views differ from those of patients. Physicians emphasize the difficulty in elaborating treatment strategies and the need for a tool to help in treatment choice. CONCLUSIONS: This qualitative study suggests several ways to improve the patient-practitioner relationship and the efficacy of treatment strategies, by increasing their acceptability and compliance. Providing adapted and formalized information to patients, adopting more global assessment and therapeutic approaches, and dealing more accurately with patients' paradoxal representation of drug therapy are main factors of improvement that should be addressed

The microdistri bution of isoenzymic strains of Trypanosoma cruzi in southern Bolivia; new isoenzyme profiles and further arguments aga i nst Mendel ia n sexuality

Summary 132 Typanosoma cruzi stocks were collected in southern Bolivia (99 stocks in Tupiza, 33 in Tarija), and were characterized using five enzymes (six loci). From these 132 stocks, a sample of 21 was studied using 10 enzymes (12 loci) to establish the genetic distances between them. Only five different isoenzymic strains were registered among the 132 stocks: the taxonomic status of these strains is discussed. The distribution of the strains indicated that a Founder effect was not a constant fact at the level of the house and of the suburb, but that a Founder effect was more apparent for greater geographical distances. All strains were transmitted sympatrically by the same vector Triatoma illfestans. Genotype frequencies demonstrated the lack of Mendelian sexuality among stocks of T. cruzi from southern Bolivia, confirming our previous results

Post-Kala-azar Dermal Leishmaniasis in Nepal: A Retrospective Cohort Study (2000–2010)

Post-kala-azar dermal leishmaniasis (PKDL) is a skin disorder seen in patients treated for Leishmania donovani visceral leishmaniasis (VL), a neglected tropical disease that is fatal if left untreated. In the Indian subcontinent, PKDL is seen in 5–10% of all past VL cases and is also reported in some without history of VL. As persons with PKDL do not feel sick, the disease has only cosmetic significance for the individual and treatment is rarely sought. However, PKDL lesions harbour parasites and therefore could represent a source of transmission, through the bite of female sand flies. Our study shows that the occurrence of PKDL in patients with past treated VL is low in Nepal compared to neighboring countries. Treatment of the original VL episode with SSG (sodium stibogluconate), inadequate treatment and treatment on ambulatory basis were significantly associated with PKDL. Though SSG has since been replaced by other drugs, counseling and supervision of adherence to the prescribed VL treatment is of vital importance to reduce risk of treatment failure and relapse as well as later development of PKDL. Policy makers should include surveillance and case management of PKDL in the VL elimination program

Cryptic Leishmania infantum infection in Italian HIV infected patients

<p>Abstract</p> <p>Background</p> <p>Visceral leishmaniasis (VL) is a protozoan diseases caused in Europe by <it>Leishmania (L.) infantum</it>. Asymptomatic <it>Leishmania </it>infection is more frequent than clinically apparent disease. Among HIV infected patients the risk of clinical VL is increased due to immunosuppression, which can reactivate a latent infection. The aims of our study were to assess the prevalence of asymptomatic <it>L. infantum </it>infection in HIV infected patients and to study a possible correlation between <it>Leishmania </it>parasitemia and HIV infection markers.</p> <p>Methods</p> <p>One hundred and forty-five HIV infected patients were screened for the presence of anti-<it>Leishmania </it>antibodies and <it>L. infantum </it>DNA in peripheral blood. Statistical analysis was carried out by using a univariate regression analysis.</p> <p>Results</p> <p>Antibodies to <it>L. infantum </it>were detected in 1.4% of patients. <it>L. infantum </it>DNA was detected in 16.5% of patients. Significant association for PCR-<it>Leishmania </it>levels with plasma viral load was documented (p = 0.0001).</p> <p>Conclusion</p> <p>In our area a considerable proportion of HIV infected patients are asymptomatic carriers of <it>L. infantum </it>infection. A relationship between high HIV viral load and high parasitemic burden, possibly related to a higher risk of developing symptomatic disease, is suggested. PCR could be used for periodic screening of HIV patients to individuate those with higher risk of reactivation of <it>L. infantum </it>infection.</p

Transcription of toll-like receptors 2, 3, 4 and 9, FoxP3 and Th17 cytokines in a susceptible experimental model of canine Leishmania infantum infection

Canine leishmaniosis (CanL) due to Leishmania infantum is a chronic zoonotic systemic disease resulting from complex interactions between protozoa and the canine immune system. Toll-like receptors (TLRs) are essential components of the innate immune system and facilitate the early detection of many infections. However, the role of TLRs in CanL remains unknown and information describing TLR transcription during infection is extremely scarce. The aim of this research project was to investigate the impact of L. infantum infection on canine TLR transcription using a susceptible model. The objectives of this study were to evaluate transcription of TLRs 2, 3, 4 and 9 by means of quantitative reverse transcription polymerase chain reaction (qRT-PCR) in skin, spleen, lymph node and liver in the presence or absence of experimental L. infantum infection in Beagle dogs. These findings were compared with clinical and serological data, parasite densities in infected tissues and transcription of IL-17, IL-22 and FoxP3 in different tissues in non-infected dogs (n = 10), and at six months (n = 24) and 15 months (n = 7) post infection. Results revealed significant down regulation of transcription with disease progression in lymph node samples for TLR3, TLR4, TLR9, IL-17, IL-22 and FoxP3. In spleen samples, significant down regulation of transcription was seen in TLR4 and IL-22 when both infected groups were compared with controls. In liver samples, down regulation of transcription was evident with disease progression for IL-22. In the skin, upregulation was seen only for TLR9 and FoxP3 in the early stages of infection. Subtle changes or down regulation in TLR transcription, Th17 cytokines and FoxP3 are indicative of the silent establishment of infection that Leishmania is renowned for. These observations provide new insights about TLR transcription, Th17 cytokines and Foxp3 in the liver, spleen, lymph node and skin in CanL and highlight possible markers of disease susceptibility in this model