Complement system in cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) consists 20% of keratinocytederived non-melanoma skin cancers (NMSC), the incidence of which is increasing globally. cSCC is the most common metastatic skin cancer and it causes approximately 20% of skin cancer-related deaths. At present, there are no molecular markers for predicting which cSCC lesions are aggressive or metastasize rapidly. UV radiation is the most important risk factor for cSCC. During the development of cSCC, normal epidermal keratinocytes are transformed and form actinic keratosis (AK), which progresses to cSCC in situ (cSCCIS, Bowen’s disease) and finally to invasive and metastatic cSCC. Inflammatory factors and cells are a part of cancer microenvironment and cSCC can develop in the chronically irritated skin or in the context of chronic inflammation. The complement system is a central part of innate immunity and it regulates normal immunological and inflammatory processes. In this study, the role of complement system components and inhibitors were studied in the progression of cSCC in culture and in vivo. Elevated expression of complement factor H (CFH), complement factor I (CFI), complement component C3 and complement factor B (CFB) was noted in cSCC cells in culture. The analysis with immunohistochemistry (IHC) revealed that the expression of CFH, CFI, C3 and CFB was specifically noted in tumor cells in vivo. The staining intensity of CFH, CFI, C3 and CFB was also stronger in invasive cSCC than in AK or cSCCIS samples. The knockdown of CFH, CFI and CFB with specific siRNAs decreased cSCC cell viability and migration, whereas the knockdown of C3 reduced only cSCC cell migration. Moreover, the knockdown of CFI, C3 and CFB inhibited growth of cSCC xenograft tumors established in SCID mice in vivo. In these tumors, CFI, C3 and CFB knockdown decreased the number of proliferating cells. Moreover, the knockdown of CFI increased local inflammation and complement activation. This study provides evidence for the roles of CFH, CFI, C3 and CFB in the tumor progression indicating these as molecular biomarkers and putative therapeutic targets of cSCC.

Pharmacokinetic and parasitological evaluation of the bone marrow of dogs with visceral leishmaniasis submitted to multiple dose treatment with liposome-encapsulated meglumine antimoniate

The aim of the present study was to evaluate the impact of a multiple dose regimen of a liposomal formulation of meglumine antimoniate (LMA) on the pharmacokinetics of antimony in the bone marrow of dogs with visceral leishmaniasis and on the ability of LMA to eliminate parasites from this tissue. Dogs naturally infected with Leishmania chagasi received 4 intravenous doses of either LMA (6.5 mg antimony/kg body weight, N = 9), or empty liposomes (at the same lipid dose as LMA, N = 9) at 4-day intervals. A third group of animals was untreated (N = 8). Before each administration and at different times after treatment, bone marrow was obtained and analyzed for antimony level (LMA group) by electrothermal atomic absorption spectrometry, and for the presence of Leishmania parasites (all groups). There was a significant increase of antimony concentration from 0.76 µg/kg wet organ (4 days after the first dose) to 2.07 µg/kg (4 days after the fourth dose) and a half-life of 4 days for antimony elimination from the bone marrow. Treatment with LMA significantly reduced the number of dogs positive for parasites (with at least one amastigote per 1000 host cells) compared to controls (positive dogs 30 days after treatment: 0 of 9 in the LMA group, 3 of 9 in the group treated with empty liposomes and 3 of 8 in the untreated group). However, complete elimination of parasites was not achieved. In conclusion, the present study showed that multiple dose treatment with LMA was effective in improving antimony levels in the bone marrow of dogs with visceral leishmaniasis and in reducing the number of positive animals, even though it was not sufficient to achieve complete elimination of parasites.

Leishmania (Leishmania) chagasi-infected mice as a model for the study of glomerular lesions in visceral leishmaniasis

Renal involvement in visceral leishmaniasis (VL) is very frequent but the pathogenesis of this nephropathy is poorly understood. In previous studies using dogs with VL we have detected new immunopathological elements in the glomeruli such as T cells and adhesion molecules. Although Leishmania (Leishmania) chagasi-infected dogs and hamsters are considered to be good models for VL, their use is limited for immunopathologic studies. The use of isogenic mouse strains susceptible to L. (L.) chagasi infection was an alternative but, on the other hand, the renal lesions of these animals have not yet been characterized. Thus, our purpose in the present study was to characterize mice infected with L. (L.) chagasi as a suitable model to study VL nephropathy. Kidney samples were obtained from control mice (N = 12) and from BALB/c mice (N = 24) injected intraperitoneally with 20 million L. (L.) chagasi amastigotes 7, 15, and 30 days after injection and processed for histopathological studies and detection of IgG deposits. Glomerular hypercellularity was clearly visible and, upon Mason's trichrome and periodic acid methenamine silver staining, a pattern suggestive of mesangial proliferative glomerulonephritis was observed in mice with VL. Time-dependent IgG deposits were also seen in infected mice. We consider L. (L.) chagasi-infected mice to be a suitable model for studies of the immunopathogenesis of glomerular lesions in VL.

Effect of gallium-arsenide laser, gallium-aluminum-arsenide laser and healing ointment on cutaneous wound healing in Wistar rats

This study determined the effects of gallium-aluminum-arsenide laser (GaAlAs), gallium-arsenide laser (GaAs) and Dersani® healing ointment on skin wounds in Wistar rats. The parameters analyzed were: type I and III collagen fiber concentrations as well as the rate of wound closure. Five wounds, 12 mm in diameter, were made on the animals’ backs. The depth of the surgical incision was controlled by removing the epithelial tissue until the dorsal muscular fascia was exposed. The animals were anesthetized with ketamine and xylazine via intraperitoneal injection. The rats were randomly divided into five groups of 6 animals each, according to the treatment received. Group 1 (L4): GaAs laser (4 J/cm²); group 2 (L30): GaAlAs laser (30 J/cm²); group 3 (L60): GaAlAs laser (60 J/cm²); group 4 (D): Dersani® ointment; group 5 (control): 0.9% saline. The applications were made daily over a period of 20 days. Tissue fragments were stained with picrosirius to distinguish type I collagen from type III collagen. The collagen fibers were photo-documented and analyzed using the Quantum software based on the primary color spectrum (red, yellow and blue). Significant results for wound closing rate were obtained for group 1 (L4), 7.37 mm/day. The highest concentration of type III collagen fibers was observed in group 2 (L30; 37.80 ± 7.10%), which differed from control (29.86 ± 5.15%) on the 20th day of treatment. The type I collagen fibers of group 1 (L4; 2.67 ± 2.23%) and group 2 (L30; 2.87 ± 2.40%) differed significantly from control (1.77 ± 2.97%) on the 20th day of the experiment.

In vitro activity of hypnophilin from Lentinus strigosus: a potential prototype for Chagas disease and leishmaniasis chemotherapy

Hypnophilin and panepoxydone, terpenoids isolated from Lentinus strigosus, have significant inhibitory activity onTrypanosoma cruzi trypanothione reductase (TR). Although they have similar TR inhibitory activity at 10 μg/mL (40.3 μM and 47.6 μM for hypnophilin and panepoxydone, respectively; ~100%), hypnophilin has a slightly greater inhibitory activity (~71%) on T. cruzi amastigote (AMA) growth in vitro as well as on in vitro phytohemagglutinin (PHA)-induced peripheral blood mononuclear (PBMC) proliferation (~70%) compared to panepoxydone (69% AMA inhibition and 91% PBMC inhibition). Hypnophilin and panepoxydone at 1.25 μg/mL had 67% inhibitory activity onLeishmania (Leishmania) amazonensis amastigote-like (AMA-like) growth in vitro. The panepoxydone activity was accompanied by a significant inhibitory effect on PHA-induced PBMC proliferation, suggesting a cytotoxic action. Moreover, incubation of human PBMC with panepoxydone reduced the percentage of CD16+ and CD14+ cells and down-regulated CD19+, CD4+ and CD8+ cells, while hypnophilin did not alter any of the phenotypes analyzed. These data indicate that hypnophilin may be considered to be a prototype for the design of drugs for the chemotherapy of diseases caused by Trypanosomatidae.

Photodynamic antimicrobial chemotherapy (PACT) for the treatment of malaria, leishmaniasis and trypanosomiasis

A photodynamic effect occurs when photosensitiser molecules absorb light and dissipate the absorbed energy by transferring it to biological acceptors (usually oxygen), generating an excess of reactive species that are able to force cells into death pathways. Several tropical diseases present physiopathological aspects that are accessible to the application of a photosensitiser and local illumination. In addition, disease may be transmitted through infected blood donations, and many of the aetiological agents associated with tropical diseases have been shown to be susceptible to the photodynamic approach. However, there has been no systematic investigation of the application of photoantimicrobial agents in the various presentations, whether to human disease or to the disinfection of blood products or even as photo-insecticides. We aim in this review to report the advances in the photoantimicrobial approach that are beneficial to the field of anti-parasite therapy and also have the potential to facilitate the development of low-cost/high-efficiency protocols for underserved populations.

Experimental models in vaccine research: malaria and leishmaniasis

Animal models have a long history of being useful tools, not only to test and select vaccines, but also to help understand the elaborate details of the immune response that follows infection. Different models have been extensively used to investigate putative immunological correlates of protection against parasitic diseases that are important to reach a successful vaccine. The greatest challenge has been the improvement and adaptation of these models to reflect the reality of human disease and the screening of vaccine candidates capable of overcoming the challenge of natural transmission. This review will discuss the advantages and challenges of using experimental animal models for vaccine development and how the knowledge achieved can be extrapolated to human disease by looking into two important parasitic diseases: malaria and leishmaniasis.

Reconstructive dosimetry for cutaneous radiation syndrome

According to the International Atomic Energy Agency (IAEA), a relatively significant number of radiological accidents have occurred in recent years mainly because of the practices referred to as potentially high-risk activities, such as radiotherapy, large irradiators and industrial radiography, especially in gammagraphy assays. In some instances, severe injuries have occurred in exposed persons due to high radiation doses. In industrial radiography, 80 cases involving a total of 120 radiation workers, 110 members of the public including 12 deaths have been recorded up to 2014. Radiological accidents in industrial practices in Brazil have mainly resulted in development of cutaneous radiation syndrome (CRS) in hands and fingers. Brazilian data include 5 serious cases related to industrial gammagraphy, affecting 7 radiation workers and 19 members of the public; however, none of them were fatal. Some methods of reconstructive dosimetry have been used to estimate the radiation dose to assist in prescribing medical treatment. The type and development of cutaneous manifestations in the exposed areas of a person is the first achievable gross dose estimation. This review article presents the state-of-the-art reconstructive dosimetry methods enabling estimation of local radiation doses and provides guidelines for medical handling of the exposed individuals. The review also presents the Chilean and Brazilian radiological accident cases to highlight the importance of reconstructive dosimetry.

Roles of novel biomarkers in progression of cutaneous squamous cell carcinoma

Roles of novel biomarkers was studied in progression of cutaneous squamous cell carcinoma (cSCC) as the most common metastatic skin cancer. The incidence of cSCC is increasing worldwide due to lifestyle changes such as recreational exposure to sunlight and the aging of the population. Because of an emerging need for molecular markers for the progression of cSCC, we set our goal to characterize three distinct novel markers overexpressed in cSCC cells. Our results identified overexpression of serpin peptidase inhibitor clade A member 1 (SerpinA1), EphB2 and absent in melanoma 2 (AIM2) in cSCC cell lines compared with normal human epidermal keratinocytes (NHEKs). Immunohistochemical analysis of SerpinA1, EphB2 and AIM2 revealed abundant tumor cell-specific expression of cytoplasmic SerpinA1 and AIM2 and cytoplasmic and membranous EphB2 in cSCC tumors in vivo. The staining intensity of SerpinA1, EphB2 and AIM2 was significantly stronger in cSCC as compared with carcinoma in situ (cSCCIS) and actinic keratosis (AK). Tumor cell-associated SerpinA1 and EphB2 was noted in chemically induced mouse skin SCC, and the staining intensity was stronger in mouse cSCCs than in untreated skin. AIM2 staining intensity was significantly more abundant in cSCC of organ transplant recipients (OTR) than in sporadic cSCC in vivo. EphB2 knockdown resulted in inhibition of migration in cSCC cells. In addition, knockdown of EphB2 and AIM2 was found to inhibit the proliferation and invasion of cSCC cells and to delay the growth and vascularization of cSCC xenografts in vivo. Altogether, these findings identify SerpinA1 as a novel biomarker for cSCC. In addition, characterization of the roles of EphB2 and AIM2 in the progression of cSCC was implicated them as possible therapeutic targets for the treatment of cSCC particularly in unresectable and metastatic tumors.

Bionomía de Lutzomyia spp. (Diptera: psychodidae) vectores de Leishmaniasis cutánea localizada en el área endémica del ejido La Libertad, Escárcega, Campeche, México [por] Eduardo Alfonso Rebollar Téllez

Tesis (Maestro en Ciencias con Especialidad en Entomología Médica ) U.A.N.L.

Dinámica de infección de Leishmaniasis y fluctuación poblacional de Lutzomyia spp. ( Díptera: Psychodidae) en cafetales de Nayarit, México

Tesis ( Doctorado en Ciencias Biológicas con Especialidad en Entomología Médica) UANL

Identification and characterization of novel virulence factors from the swine pathogen and zoonotic agent streptococcus suis

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Functional organization of cutaneous reflex pathways during locomotion and reorganization following peripheral nerve and/or spinal cord lesions

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Identification of a novel herpesvirus associated with cutaneous ulcers in a fisher (Martes pennanti).

On December 8, 2008, a male fisher (Martes pennanti) housed in a quarantine enclosure at the St-Félicien Zoo was found dead with multiple skin ulcers on the muzzle and plantar pads. At necropsy, no major findings were found, and a specific cause of death was not determined microscopically. However, at the borders of ulcerated sites, there were increased numbers of koilocytes, with perinuclear vacuolation and nuclear enlargement. A pan-herpesvirus nested polymerase chain reaction (PCR) assay was conducted, and an expected PCR product of 230 nucleotides was obtained within tissues collected from around the skin ulcers. Other tissues, including intestines and pool of lung, liver, and kidney, tested negative. The obtained PCR amplicon was sequenced and was highly related to the partial viral DNA polymerase (DPOL) gene of Mustelid herpesvirus 1. Virus isolation was negative, and no virion was detected by electron microscopy. The pathogenic potential of this novel herpesvirus and its role in the death of the fisher are unknown.

Permeación en piel humana de una nanoemulsión de ftalocianina de aluminio clorada para la optimización de tratamientos tópicos de leishmaniasis cutánea

Introducción: Las nanoemulsiones son excelentes sistemas de transporte y entrega de fármacos. La ftalocianina de aluminio clorada (PcAlCl) en terapia fotodinámica constituye una alternativa de tratamiento en leishmaniasis cutánea. Objetivo: Determinar la difusión y retención en piel humana de la PcAlCl contenida en una nanoemulsión (nano-PcAlCl) para su optimización en formulaciones tópicas. Materiales y métodos: Se prepararon y caracterizaron fisico-químicamente dos formulaciones (nano-PcAlCl y solución-PcAlCl) y sus vehículos sin-PcAlCl. La permeación se determinó en ensayos en celdas de difusión de Franz y la retención por el método de la cinta adhesiva. La concentración de PcAlCl fue determinada fluorométricamente (nM/cm2). Biopsias de piel fueron analizadas histotécnicamente. Resultados: El tamaño promedio, el potencial Z y el índice de polidispersión de la nano-PcAlCl en agua fue de 132,9 nm, -19,23 y 0,14 y diluida en PBS fue 125,33 nm, -13,69 y 0,139. Las concentraciones de PcAlCl se mantuvieron estables. La PcAlCl no atravesó la piel y fue retenida en sus capas, en estrato córneo y epidermis+dermis con valores de 44,17 nM y 8,48 nM postratamiento con nano-PcAlCl, y 96,90 nM y 9,80 nM postratamiento con solución-PcAlCl. Esta última promovió mayor retención en estrato córneoy ambas formulaciones promovieron similar retención en epidermis+dermis. Se observódesprendimiento del estrato córneo y fragmentación del colágeno. Conclusión: La PcAlCl noatravesó la piel, se retuvo en estrato córneo y epidermis+dermis. Se sugiere realizar ensayos depermeación utilizando piel humana desprovista de estrato córneo y ensayos de distribución enanimales con leishmaniasis cutánea.