Hourly activity of Lutzomyia neivai in the endemic zone of cutaneous leishmaniasis in Tucumán, Argentina: preliminary results

In the present work, the hourly activity of Lutzomyia neivai was studied in the southern part of the province of Tucumán, Argentina, in an area of transmission of cutaneous leishmaniasis during two months of higher activity. In addition, the variables that influenced the abundance of Lu. neivai were evaluated. A total of 1,146 individuals belonging to Lu. neivai (97%) and Lutzomyia migonei (3%) were captured. The hourly activity of Lu. neivai was mainly nocturnal, with a bimodal pattern in both months. In January, the variable that most influenced the abundance of Lu. neivai was the temperature, whereas in April, that variable was humidity. These results may contribute to the design of anti-vectorial control measures at a micro-focal scale.

Correction: Frequent MAGE Mutations in Human Melanoma.

[This corrects the article on p. e12773 in vol. 5.].

Schistosoma mansoni antigens alter the cytokine response in vitro during cutaneous leishmaniasis

Schistosoma mansoni infection or associated products are able to down-modulate the type 1 CD4+ T cell inflammatory response characteristic of autoimmune diseases. In this study, we evaluated how S. mansoni antigens altered the immune response that was induced by the soluble Leishmania antigen (SLA) from cutaneous leishmaniasis (CL) patients. Cytokines were measured from the supernatants of peripheral blood mononuclear cell cultures stimulated with SLA. This was performed using the sandwich enzyme linked immunosorbent assay technique in the presence or absence of S. mansoni recombinant antigens Sm29, SmTSP-2 and PIII. The addition of S. mansoni antigens to the cultures resulted in the reduction of interferon gamma (IFN-γ) levels in 37-50% of patients. Although to a lesser extent, the antigens were also able to decrease the production of tumour necrosis factor-alpha (TNF-α). We compared patients that either had or did not have reduction in IFN-γ and TNF-α production in cultures stimulated with SLA in the presence of S. mansoni antigens. We found that there was no significant difference in the levels of interleukin (IL)-10 and IL-5 in response to S. mansoni antigens between the groups. The antigens used in this study down-modulated the in vitro proinflammatory response induced by SLA in a group of CL patients through a currently undefined mechanism.

Anthropogenic influence on the distribution, abundance and diversity of sandfly species (Diptera: Phlebotominae: Psychodidae), vectors of cutaneous leishmaniasis in Panama

In Panama, species of the genus Lutzomyia are vectors of American cutaneous leishmaniasis (ACL). There is no recent ecological information that may be used to develop tools for the control of this disease. Thus, the goal of this study was to determine the composition, distribution and diversity of Lutzomyia species that serve as vectors of ACL. Sandfly sampling was conducted in forests, fragmented forests and rural environments, in locations with records of ACL. Lutzomyia gomezi, Lutzomyia panamensis and Lutzomyia trapidoi were the most widely distributed and prevalent species. Analysis of each sampling point showed that the species abundance and diversity were greatest at points located in the fragmented forest landscape. However, when the samples were grouped according to the landscape characteristics of the locations, there was a greater diversity of species in the rural environment locations. The Kruskal Wallis analysis of species abundance found that Lu. gomezi and Lu. trapidoi were associated with fragmented environments, while Lu. panamensis, Lutzomyia olmeca bicolor and Lutzomyia ylephiletor were associated with forested environments. Therefore, we suggest that human activity influences the distribution, composition and diversity of the vector species responsible for leishmaniasis in Panama.

Recent advances and hurdles in melanoma immunotherapy.

Worldwide incidence of malignant melanoma has been constantly increasing during the last years. Surgical excision is effective when primary tumours are thin. At later disease stages patients often succumb, due to failure of metastasis control. Therefore, great efforts have been made to develop improved strategies to treat metastatic melanoma patients. In the search for novel treatments during the last two decades, immunotherapy has occupied a prominent place. Numerous early phase immunotherapy clinical trials, generally involving small numbers of patients each time, have been reported: significant tumour-specific immune responses could often be measured in patients upon treatments. However, clinical responses remain at a dismal low rate. In some anecdotal cases, objective clinical benefit was more frequently observed among immune responders than immune non-responders. This clearly calls for a better understanding of protective immunity against tumours as well as the cross talk taking place between tumours and the immune system. Here we discuss advances and limitations of specific immunotherapy against human melanoma in the light of the literature from the last 5 yr.

Report of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae: Phlebotominae) in a cutaneous-leishmaniasis-endemic area of Panama

Lutzomyia longipalpis is the primary vector of the parasite responsible for visceral leishmaniasis in the Americas. In the present study, Lu. longipalpis was found in a domiciliary area in Limón, a district in Capira, a region in which cutaneous leishmaniasis is endemic in Panama. Previously, this species has been found in a humid forest in this same region. Finding Lu. longipalpis in domiciliary areas indicates that this species may be adapting to new habitats and that it may play a role in the transmission of leishmaniasis in Panama.

A morphologically distinct Phlebotomus argentipes population from active cutaneous leishmaniasis foci in central Sri Lanka

Although the reported aetiological agent of cutaneous leishmaniasis (CL) in Sri Lanka is Leishmania donovani, the sandfly vector remains unknown. Ninety-five sandflies, 60 females and 35 males, collected in six localities in the district of Matale, central Sri Lanka, close to current active transmission foci of CL were examined for taxonomically relevant characteristics. Eleven diagnostic morphological characters for female sandflies were compared with measurements described for Indian and Sri Lankan sandflies, including the now recognised Phlebotomus argentipes sensu lato species complex. The mean morphometric measurements of collected female sandflies differed significantly from published values for P. argentipes morphospecies B, now re-identified as Phlebotomus annandalei from Delft Island and northern Sri Lanka, from recently re-identified P. argentipes s.s. sibling species and from Phlebotomus glaucus. Furthermore, analysis of underlying variation in the morphometric data through principal component analysis also illustrated differences between the population described herein and previously recognised members of the P. argentipes species complex. Collectively, these results suggest that a morphologically distinct population, perhaps most closely related to P. glaucus of the P. argentipess. I. species complex, exists in areas of active CL transmission. Thus, research is required to determine the ability of this population of flies to transmit cutaneous leishmaniasis.

Development and validation of PCR-based assays for diagnosis of American cutaneous leishmaniasis and identificatio nof the parasite species

In this study, PCR assays targeting different Leishmania heat-shock protein 70 gene (hsp70) regions, producing fragments ranging in size from 230-390 bp were developed and evaluated to determine their potential as a tool for the specific molecular diagnosis of cutaneous leishmaniasis (CL). A total of 70 Leishmania strains were analysed, including seven reference strains (RS) and 63 previously typed strains. Analysis of the RS indicated a specific region of 234 bp in the hsp70 gene as a valid target that was highly sensitive for detection of Leishmania species DNA with capacity of distinguishing all analyzed species, after polymerase chain reaction-restriction fragment length polymorfism (PCR-RFLP). This PCR assay was compared with other PCR targets used for the molecular diagnosis of leishmaniasis: hsp70 (1400-bp region), internal transcribed spacer (ITS)1 and glucose-6-phosphate dehydrogenase (G6pd). A good agreement among the methods was observed concerning the Leishmania species identification. Moreover, to evaluate the potential for molecular diagnosis, we compared the PCR targets hsp70-234 bp, ITS1, G6pd and mkDNA using a panel of 99 DNA samples from tissue fragments collected from patients with confirmed CL. Both PCR-hsp70-234 bp and PCR-ITS1 detected Leishmania DNA in more than 70% of the samples. However, using hsp70-234 bp PCR-RFLP, identification of all of the Leishmania species associated with CL in Brazil can be achieved employing a simpler and cheaper electrophoresis protocol.

Cutaneous lesions sensory impairment recovery and nerve regeneration in leprosy patients

It is important to understand the mechanisms that enable peripheral neurons to regenerate after nerve injury in order to identify methods of improving this regeneration. Therefore, we studied nerve regeneration and sensory impairment recovery in the cutaneous lesions of leprosy patients (LPs) before and after treatment with multidrug therapy (MDT). The skin lesion sensory test results were compared to the histopathological and immunohistochemical protein gene product (PGP) 9.5 and the p75 nerve growth factor receptors (NGFr) findings. The cutaneous neural occupation ratio (CNOR) was evaluated for both neural markers. Thermal and pain sensations were the most frequently affected functions at the first visit and the most frequently recovered functions after MDT. The presence of a high cutaneous nerve damage index did not prevent the recovery of any type of sensory function. The CNOR was calculated for each biopsy, according to the presence of PGP and NGFr-immunostained fibres and it was not significantly different before or after the MDT. We observed a variable influence of MDT in the recovery from sensory impairment in the cutaneous lesions of LPs. Nociception and cold thermosensation were the most recovered sensations. The recovery of sensation in the skin lesions appeared to be associated with subsiding inflammation rather than with the regenerative activity of nerve fibres.

Specificity of the rapid rK39 antigen-based immunochromatographic test Kalazar Detect(r) in patients with cutaneous leishmaniasis in Brazil

The aim of this study was to evaluate the specificity of a rapid immunochromatographic test that was developed to detect antibodies against the rK39 antigen for the diagnosis of visceral leishmaniasis (VL). This evaluation was performed using sera from patients with a confirmed diagnosis of active cutaneous leishmaniasis. The sera from 272 patients with a confirmed diagnosis of localised cutaneous leishmaniasis (CL) who resided in an area endemic for Leishmania braziliensis in Brazil were obtained before the initiation of antileishmanial treatment. Kalazar Detect(r)(InBios, Seattle, WA) recombinant K39 antigen-based immunochromatographic strips were used according to the manufacturer's instructions. The test results were evaluated independently by two examiners in sequential order. The positive controls for the test included five serum samples from five patients with parasitologically confirmed diagnosis of VL caused by Leishmania infantum in Brazil. Overall, 100% of the samples obtained from patients with CL were negative, confirming the absence of a serological cross-reaction for individuals with cutaneous disease when these patients were evaluated using the rapid test. The lack of a cross-reaction in patients who were infected by parasites of the same genus highlights the specificity of the rK39 antigen for the diagnosis of VL in areas with the sympatric circulation of L. braziliensis and L. infantum.

The sandfly fauna, anthropophily and the seasonal activities of Pintomyia spinicrassa (Diptera: Psychodidae: Phlebotominae) in a focus of cutaneous leishmaniasis in northeastern Colombia

This study was conducted to identify the sandfly fauna and the anthropophilic species in a coffee-growing area of Villanueva, Norte de Santander, Colombia, a focus of American cutaneous leishmaniasis, and to analyse the relationship between the most frequent species and rainfall, relative humidity and temperature, with the aim of contributing to epidemiological surveillance in the area. Sandfly collections were performed fortnightly between February 2006-September 2007 using automatic light traps, Shannon traps, protected human bait and aspiration in resting places. A total of 7,051 sandflies belonging to 12 species were captured. Pintomyia spinicrassa (95.7%) predominated. Pintomyia oresbia and Lutzomyia sp. of Pichinde were found in the state of Norte de Santander for the first time. Pi. spinicrassa, Pintomyia nuneztovari, Micropygomyia venezuelensis, Lutzomyia (Helcocyrtomyia) scorzai and Lu. (Helcocyrtomyia) sp. were captured on the protected human bait. A significant association between Pi. spinicrassa abundance and the total rainfall and the average temperature and humidity 10 days before the collection was observed. The dominance of Pi. spinicrassa, a recognised vector of Leishmania braziliensis, especially during the dry periods, indicates that the risk of parasite transmission may increase.

Sandflies (Diptera: Psychodidae) in rural and urban environments in an endemic area of cutaneous leishmaniasis in southern Brazil

The high proportion of cases of cutaneous leishmaniasis reported amongst residents in the city of Bandeirantes, in the state of Paraná, Brazil, led the authors to investigate the phlebotomine fauna in both urban and rural environments. The sandflies were captured with automatic light traps from 07:00 pm-07:00 am fortnightly in 11 urban peridomiciles from April 2008-March 2009 and monthly in three ecotopes within four rural localities from April 2009-March 2010. In one of these latter localities, sandfly capture was conducted with white/black Shannon traps during each of three seasons: spring, summer and fall. A total of 5,729 sandflies of 17 species were captured. Nyssomyia neivai (46.7%) and Nyssomyia whitmani (35.3%) were the predominant species. In this study, 3,865 specimens were captured with automatic light traps: 22 (0.083 sandflies/trap) in the urban areas and 3,843 (26.69 sandflies/trap) in the rural areas. Ny. neivai was predominant in urban (68.2%) and rural (42.8%) areas. A total of 1,864 specimens were captured with the white/black Shannon traps and Ny. neivai (54.5%) and Ny. whitmani (31.4%) were the predominant species captured. The small numbers of sandflies captured in the urban areas suggest that the transmission of Leishmania has occurred in the rural area due to Ny. neivai and Ny. whitmani as the probable vectors.

Trans-scleral local resection of toxic choroidal melanoma after proton beam radiotherapy.

AIM: To report on trans-scleral local resection of choroidal melanoma for exudative retinal detachment and neovascular glaucoma (toxic tumour syndrome) after proton beam radiotherapy (PBR). METHODS: A non-randomised, prospective study of secondary trans-scleral local resection of choroidal melanoma for exudative retinal detachment with or without neovascular glaucoma after PBR. The patients were treated at the Liverpool Ocular Oncology Centre between February 2000 and April 2008. The trans-scleral local resection was performed with a lamellar-scleral flap, using systemic hypotension to reduce haemorrhage. RESULTS: 12 patients (six women, six men) with a mean age of 51 years (range 20-75) were included in this study. The tumour margins extended anterior to ora serrata in six patients. On ultrasonography, the largest basal tumour dimension averaged 12.4 mm (range 6.8-18.1) and the tumour height averaged 7.1 mm (range 4.2-10.7). The retinal detachment was total in seven patients. Neovascular glaucoma was present in four patients. The time between PBR and local resection had a mean of 17.4 months (range 1-84). The ophthalmic follow-up time after the local resection had a mean of 46.2 months (range 14-99). At the latest known status, the eye was conserved in 10 patients, with a flat retina in all these patients and visual acuity equal or better than 6/30 in four patients. The reasons for enucleation were: patient request for enucleation when rhegmatogenous retinal detachment complicated the resection (one patient) and phthisis (one patient). CONCLUSIONS: Exudative retinal detachment, rubeosis and neovascular glaucoma after PBR of a choroidal melanoma can resolve after trans-scleral local resection of the tumour. Our findings suggest that these complications are caused by the persistence of the irradiated tumour within the eye ('toxic tumour syndrome').

Detection of Wolbachia pipientis, including a new strain containing the wsp gene, in two sister species of Paraphlebotomus sandflies, potential vectors of zoonotic cutaneous leishmaniasis

Individual, naturally occurring Phlebotomus mongolensis and Phlebotomus caucasicus from Iran were screened for infections with the maternally inherited intracellular Rickettsia-like bacterium Wolbachia pipientis via targeting a major surface protein gene (wsp). The main objective of this study was to determine if W. pipientis could be detected in these species. The sandflies were screened using polymerase chain reaction to amplify a fragment of the Wolbachia surface protein gene. The obtained sequences were edited and aligned with database sequences to identify W. pipientis haplotypes. Two strains of Wolbachia were found. Strain Turk 54 (accession EU780683) is widespread and has previously been reported in Phlebotomus papatasi and other insects. Strain Turk 07 (accession KC576916) is a novel strain, found for first time in the two sister species. A-group strains of W. pipientis occur throughout much of the habitat of these sandflies. It is possible that Wolbachia is transferred via horizontal transmission. Horizontal transfer could shed light on sandfly control because Wolbachia is believed to drive a deleterious gene into sandflies that reduces their natural population density. With regard to our findings in this study, we can conclude that one species of sandfly can be infected with different Wolbachia strains and that different species of sandflies can be infected with a common strain.

Chemokines and chemokine receptors expression in the lesions of patients with American cutaneous leishmaniasis

American cutaneous leishmaniasis (ACL) presents distinct active clinical forms with different grades of severity, known as localised (LCL), intermediate (ICL) and diffuse (DCL) cutaneous leishmaniasis. LCL and DCL are associated with a polarised T-helper (Th)1 and Th2 immune response, respectively, whereas ICL, or chronic cutaneous leishmaniasis, is associated with an exacerbated immune response and a mixed cytokine expression profile. Chemokines and chemokine receptors are involved in cellular migration and are critical in the inflammatory response. Therefore, we evaluated the expression of the chemokines CXCL10, CCL4, CCL8, CCL11 and CXCL8 and the chemokine receptors CCR3, CXCR3, CCR5 and CCR7 in the lesions of patients with different clinical forms of ACL using immunohistochemistry. LCL patients exhibited a high density of CXCL10+, CCL4+ and CCL8+ cells, indicating an important role for these chemokines in the local Th1 immune response and the migration of CXCR3+ cells. LCL patients showed a higher density of CCR7+ cells than ICL or DCL patients, suggesting major dendritic cell (DC) migration to lymph nodes. Furthermore, DCL was associated with low expression levels of Th1-associated chemokines and CCL11+ epidermal DCs, which contribute to the recruitment of CCR3+ cells. Our findings also suggest an important role for epidermal cells in the induction of skin immune responses through the production of chemokines, such as CXCL10, by keratinocytes.