Therapy of Venezuelan patients with severe mucocutaneous or early lesions of diffuse cutaneous leishmaniasis with a vaccine containing pasteurized Leishmania promastigotes and bacillus Calmette-Guerin: preliminary report

Severe mucocutaneous (MCL) and diffuse (DCL) forms of American cutaneous leishmaniasis (ACL) are infrequent in Venezuela. Chemotherapy produces only transitory remission in DCL, and occasional treatment failures are observed in MCL. We have evaluated therapy with an experimental vaccine in patients with severe leishmaniasis. Four patients with MCL and 3 with early DCL were treated with monthly intradermal injections of a vaccine containing promastigotes of Leishmania (Viannia) braziliensis killed by pasteurization and viable Bacillus Calmette- Guerin. Clinical and immunological responses were evaluated. Integrity of protein constituents in extracts of pasteurized promastigotes was evaluated by gel electrophoresis. Complete remission of lesions occurred after 5-9 injections in patients with MCL or 7-10 injections in patients with early DCL. DCL patients developed positive skin reactions, average size 18.7 mm. All have been free of active lesions for at least 10 months. Adverse effects of the vaccine were limited to local reactivity to BCG at the injection sites and fever in 2 patients. Extracts of pasteurized and fresh promastigotes did not reveal differences in the integrity of protein components detectable by gel electrophoresis. Immunotherapy with this modified vaccine offers an effective, safe option for the treatment of patients who do not respond to immunotherapy with vaccine containing autoclaved parasites or to chemotherapy .

Participation of cytokines in the necrotic-inflammatory lesions in the heart and skeletal muscles of Calomys callosus infected with Trypanosoma cruzi

Calomys callosus, a sylvatic reservoir of Trypanosoma cruzi, when infected with the Colombian strain (Biodeme Type III, T. cruzi I ) develops necrotic-inflammatory lesions and intense early fibrogenesis in the heart and skeletal muscles, that spontaneously regress. Participation of pro-inflammatory and pro-fibrogenic cytokines, such as tumor necrosis factor-alpha (TNF-alpha), gamma interferon (IFN-gamma) , and tumor growth factor-beta (TGF-beta), in the pathogenesis of the lesions is herein studied. Eighty C. callosus weighing 20 to 30 g were used. Seventy of them were inoculated with the Colombian strain (10(5) blood forms) and 10 were maintained as intact non-infected controls. After infection, C. callosus were sacrificed at different time-points from 15 to 70 days. The heart and skeletal muscle were processed for histopathology and cryopreserved for immunohistochemistry. Early necrotic lesions of parasitized skeletal muscle and myocardium with intense inflammatory lesions were present. Search for the in situ presence of TNF-alpha and IFN-gamma, was performed using rat-IgG anti-mouse antibodies against these cytokines. For the in situ search of TGF-beta, rabbit IgG anti-mouse antibodies were used. Immunolabeling of the cytokines in tissues of infected C. callosus was successful. The cytokines TNF-alpha, IFN-gamma , and TGF-beta were detected in the cytoplasm of macrophages and in the necrotic material from 15 to 45 days post-infection, decreasing their intensity until complete disappearance by the 65th day, which correlated with subsiding histopathological lesions. These findings suggest the participation of these cytokines in the control of parasite multiplication, in the development of an early fibrogenesis and in the regression of fibrotic-inflammatory lesions observed in C. callosus.

Effector function of human tumor-specific CD8 T cells in melanoma lesions: a state of local functional tolerance.

Although tumor-specific CD8 T-cell responses often develop in cancer patients, they rarely result in tumor eradication. We aimed at studying directly the functional efficacy of tumor-specific CD8 T cells at the site of immune attack. Tumor lesions in lymphoid and nonlymphoid tissues (metastatic lymph nodes and soft tissue/visceral metastases, respectively) were collected from stage III/IV melanoma patients and investigated for the presence and function of CD8 T cells specific for the tumor differentiation antigen Melan-A/MART-1. Comparative analysis was conducted with peripheral blood T cells. We provide evidence that in vivo-priming selects, within the available naive Melan-A/MART-1-specific CD8 T-cell repertoire, cells with high T-cell receptor avidity that can efficiently kill melanoma cells in vitro. In vivo, primed Melan-A/MART-1-specific CD8 T cells accumulate at high frequency in both lymphoid and nonlymphoid tumor lesions. Unexpectedly, however, whereas primed Melan-A/MART-1-specific CD8 T cells that circulate in the blood display robust inflammatory and cytotoxic functions, those that reside in tumor lesions (particularly in metastatic lymph nodes) are functionally tolerant. We show that both the lymph node and the tumor environments blunt T-cell effector functions and offer a rationale for the failure of tumor-specific responses to effectively counter tumor progression.

Antifungal activity of propolis extract against yeasts isolated from onychomycosis lesions

The aim of this study was to determine the in vitro activity of propolis extract against 67 yeasts isolated from onychomycosis in patients attending at the Teaching and Research Laboratory of Clinical Analysis of the State University of Maringá. The method used was an adaptation made from the protocol approved by the National Committee for Clinical Laboratory Standards. The yeasts tested were: Candida parapsilosis 35%, C. tropicalis 23%, C. albicans 13%, and other species 29%. The propolis extract showed excellent performance regarding its antifungal activity: the concentration capable of inhibiting the all of the yeasts was 5 × 10-2 mg/ml of flavonoids and 2 × 10-2 mg/ml of flavonoids stimulated their cellular death. Trichosporon sp. were the most sensitive species, showing MIC50 and MIC90 of 1.25 × 10-2 mg/ml of flavonoids, and C. tropicalis was the most resistant, with CFM50 of 5 × 10-2 mg/ml of flavonoids and MFC90 of 10 × 10-2 mg/ml. In view of the fact that propolis is a natural, low cost, non-toxic product with proven antifungal activity, it should be considered as another option in the onychomycosis treatment.

Imaging of inflammatory and infectious lesions after injection of radioiodinated monoclonal anti-granulocytes antibodies.

Successful detection of inflammatory lesions by planar scintigraphy and SPECT after injection of iodine-123 labelled monoclonal antibodies directed against human granulocytes (123I-Mabgc) is demonstrated. This new tracer has been compared with indium-111 labelled white blood cells (111In-WBC) in selected patients with proven infectious lesions. Scans were equally positive in all cases, but the methodical advantages of the new marker were obvious, namely, there is no need for cell separation and the images of inflammatory lesions were better defined. In addition, SPECT could be performed with 123I-Mabgc and allowed a better anatomic localization and a three-dimensional description of the lesions. No adverse reactions have been seen. It is concluded, therefore, that 123I-Mabgc is a promising agent for the detection of acute focal inflammatory lesions which may, with advantages, replace 111In-WBC.

Capillaria hepatica in rats: focal parasitic hepatic lesions and septal fibrosis run independent courses

Capillaria hepatica causes two main lesions in the liver of rats: multifocal chronic inflammation, directly related to the presence of disintegrating parasites and their eggs, and a process of systematized septal fibrosis. The comparative behavior of these two lesions was investigated in rats experimentally infected with 600 embryonated eggs, following either corticosteroid treatment or specific antigenic stimulation, in an attempt to understand the relationship between these two lesions, and the pathogenesis of septal fibrosis. The two treatments differently modified the morphological aspects of the focal parasitic-related lesions, but did not interfere with the presentation of diffuse septal fibrosis, although a mild decrease in the degree of fibrosis occurred in corticoid-treated animals. These findings indicate that although the two lesions are C. hepatica induced, they are under different pathogenetic control, the induction of septal fibrosis being triggered during early infection to follow an independent pathway.

Trypanosoma cruzi high infectivity in vitro is related to cardiac lesions during long-term infection in Beagledogs

Trypanosoma cruzi is a hemoflagelate parasite associated with heart dysfunctions causing serious problems in Central and South America. Beagle dogs develop the symptoms of Chagas disease in humans, and could be an important experimental model for better understanding the immunopathogenic mechanisms involved in the chagasic infection. In the present study we investigated the relation among biological factors inherent to the parasite (trypomastigote polymorphism and in vitro infectivity) and immunoglobulin production, inflammation, and fibrosis in the heart of Beagle dogs infected with either T. cruzi Y or Berenice-78 strains. In vitro infectivity of Vero cells as well as the extension of cardiac lesions in infected Beagle was higher for Y strain when compared to Berenice-78 strain. These data suggested that in vitro infectivity assays may correlate with pathogenicity in vivo. In fact, animals infected with Y strain, which shows prevalence of slender forms and high infectivity in vitro, presented cardiomegaly, inflammation, and fibrosis in heart area. Concerning the immunoglobulin production, no statistically significant difference was observed for IgA, IgM or IgG levels among T. cruzi infected animals. However, IgA together IgM levels have shown to be a good marker for the acute phase of Chagas disease.

Further characterization of the executive memory impairment following frontal lobe lesions.

In this article we describe a 41-year-old man who, following an operation to repair a ruptured anterior communicating artery aneurysm, manifested the "hallmark" features of a dysexecutive memory impairment. Of particular note was the patient's apparently normal level of recognition memory but impaired recall on tasks matched for difficulty in control subjects. However, further testing revealed that the patient's recognition memory was not normal under all circumstances. Implications of these data for the interpretation and further investigation of the dysexecutive deficit are discussed.

Patterns of recovery following focal hemispheric lesions : relationship between lasting deficit and damage to specialized networks

Rapport de synthèse : Objectif : Les déficits cognitifs présents dans la phase aiguë d'une lésion hémisphérique focale ont tendance à être de nature plus importante et plus générale que les déficits résiduels qui persistent dans la phase chronique de récupération. Nous avons investigué, dans le cadre de ce travail, les modèles de récupération auditive et la relation qui se dessine entre les déficits et les dommages relatifs à des réseaux spécifiques, pris comme modèle cognitif des fonctions auditives. De nombreuses études humaines dans les domaines de la neuropsychologie, de la psychophysique ainsi que des études d'activation suggèrent que les processus de reconnaissance et de localisation sonores sont effectués par l'intermédiaire de réseaux distincts tant sur le plan anatomique que fonctionnel : il s'agit des zones de traitement du «What» et du «Where », qui sont toutes deux présentes dans les deux hémisphères. Des études ont démontré que des lésions hémisphériques focales gauches ou droites, centrées sur ces réseaux, sont associées dans la phase chronique de récupération à des déficits correspondant en ce qui concerne la reconnaissance et/ou la localisation sonore. Méthode : Dans le cadre de ce travail, nous avons analysé les résultats concernant les performances auditives chez 24 patients ayant subi des lésions hémisphériques focales avec déficits secondaires dans des tâches de reconnaissance, de localisation et/ou de perception du mouvement sonore lors d'un premier testing effectué en phase aiguë (9 patients), en phase subaiguë (6 patients) ou en phase chronique précoce (9 patients). La totalité de ces patients ont bénéficié d'un second testing en phase chronique. Les observations effectuées ont servi à l'élaboration de patterns de récupération auditive. Résultats : Tous les 24 patients avaient initialement un déficit dans le domaine de la localisation et/ou de la perception du mouvement sonore. Dans la phase aiguë, ce déficit survenait sans atteinte spécifique du réseau «Where » chez presque la moitié des patients ; en revanche, cette situation n'était jamais observée chez les patients testés en phase chronique précoce. Une absence de récupération avait tendance à être associée à un dommage spécifique au réseau concerné ainsi qu'à la persistance d'un déficit au-delà de la phase aiguë. Les déficits résiduels n'étaient par ailleurs pas strictement en lien avec la taille lésionnelle ou l'étendue de l'atteinte du réseau spécifique. Conclusion : Nos résultats suggèrent que des mécanismes distincts sous-tendent la récupération et la plasticité à différentes périodes temporelles post-lésionnelles.

Auditory spatial deficits following hemispheric lesions: Dissociation of explicit and implicit processing.

Auditory spatial deficits occur frequently after hemispheric damage; a previous case report suggested that the explicit awareness of sound positions, as in sound localisation, can be impaired while the implicit use of auditory cues for the segregation of sound objects in noisy environments remains preserved. By assessing systematically patients with a first hemispheric lesion, we have shown that (1) explicit and/or implicit use can be disturbed; (2) impaired explicit vs. preserved implicit use dissociations occur rather frequently; and (3) different types of sound localisation deficits can be associated with preserved implicit use. Conceptually, the dissociation between the explicit and implicit use may reflect the dual-stream dichotomy of auditory processing. Our results speak in favour of systematic assessments of auditory spatial functions in clinical settings, especially when adaptation to auditory environment is at stake. Further, systematic studies are needed to link deficits of explicit vs. implicit use to disability in everyday activities, to design appropriate rehabilitation strategies, and to ascertain how far the explicit and implicit use of spatial cues can be retrained following brain damage.

Tissue and serum immune response in chronic hepatitis C with mild histological lesions

The immunopathogenesis of chronic hepatitis C virus (HCV) infection is a matter of great controversy and has been suggested to involve a complex balance between cytokines with pro and anti-inflammatory activity. We investigated the expression of inflammatory cells and cytokines in the liver and serum of 51 chronically HCV infected patients and compared them to data from two sets of normal controls: 51 healthy blood donors and 33 liver biopsies of healthy liver donors. We also assessed the relationship between selected cytokines and cell populations in hepatic compartments and the disease stage. Compared with controls, hepatitis C patients had a greater expression of portal TNF-α, TGF-β and CD4+ and acinar IFN-γ, TNF-α, IL-1β and IL-4, as well as a higher serum concentration of IL-2, IL-10 and TGF-β. Significant positive correlations were found between portal CD4+ and TNF-α, portal CD8+ and TGF-β, portal CD45+RO and TNF-α, acinar CD45+RO and IFN-γ and acinar CD57+ and TGF-β. In conclusion, we have shown that (i) in this sample of predominantly mild disease, the immune response was associated with a pro-inflammatory response pattern, (ii) CD4+ T-lymphocytes played a major role in orchestrating the immune response and (iii) these events primarily took place in the portal space.

High prevalence and low E6 genetic variability of human papillomavirus 58 in women with cervical cancer and precursor lesions in Southeast Mexico

Infection with some genotypes of human papillomavirus (HPV) is the most important risk factor associated with cervical cancer (CC). Throughout the world, HPV type 58 prevalence varies from one region to another; it is higher in women from certain countries in Asia and Latin America, such as China and Mexico. Although intratypic variants have been reported on a few occasions, our knowledge about HPV 58 genetic variation remains limited. Therefore, this work aims to (i) determine the prevalence of HPV type 58 amongst Mexican women with invasive CC or precursor lesions and (ii) identify HPV 58 sequence variants. One hundred and forty five colposcopy clinic patients were studied. Genotyping of HPV 16, 18 and 58 was determined by specific nested PCR and HPV 58 variants were detected by direct sequencing. The general prevalence of HPV was 51.7% (75/145). HPV 16 was found in 30.6% (23/75) and HPV 58 in 24% (18/75) of the patients. HPV 18 was not identified in patients with cervical intraepithelial neoplasia (CIN) grade I; it was only found in those with CIN II, with a prevalence of 6.8% (3/44). In patients with CC, the prevalence of HPV 16 and 58 was 78.9%. Regarding HPV 58 variants, 94.4% of the HPV 58 sequences were identical to the prototype strain, whereas one sample showed changes at a single nucleotide. This study demonstrates a high prevalence of HPV 58 and a low genetic variability of E6 sequences amongst Mexican colposcopy patients.

Segmentació de teixit i lesions en imatges de MRI de malalts d'esclerosi múltiple

Actualment, en l'àmbit mèdic, la ressonància magnètica, MRI Magnetic Resonance Imaging, és un dels sistemes més utilitzats per a la realització de diagnòstics i el seguiment de l'evolució de malalties com l'esclerosi múltiple (EM). No obstant, la gran quantitat d'informació que proporciona aquesta modalitat té com a conseqüència una tasca feixuga d'anàlisi i d'interpretació per part dels radiòlegs i neuròlegs. L'objectiu general d'aquest projecte és desenvolupar un sistema per ajudar als metges a segmentar les imatges de MRI del cervell. S'ha implementat amb MATLAB. Durant tot el procés s'han utilitzat dades sintètiques, de la base de dades simulada BrainWeb, i reals, proporcionades pels grup de metges col•laboradors amb el grup VICOROB.El projecte s'emmarca dins d'un projecte de recerca del grup de Visió per Computador i Robòtica de la Universitat de Girona