Role of Leishmania spp. infestation in nondiagnostic cutaneous granulomatous lesions: Report of a series of patients from a Western Mediterranean area
Department of Dermatology, Hospital del Mar-IMAS, Barcelona, Spain. British Journal of Dermatology
(Impact Factor: 4.28).
07/2009; 161(2):320-5. DOI: 10.1111/j.1365-2133.2009.09282.x
Leishmaniasis is a parasitic disease prevalent in countries of the Mediterranean area.
The potential role of Leishmania as the aetiological factor for cutaneous granulomatous lesions in a series of patients from a Western Mediterranean area was evaluated. The practical usefulness of Leishmania-specific polymerase chain reaction (PCR) amplification and immunohistochemical techniques in skin biopsy specimens was assessed.
Twenty-five skin biopsies diagnosed as nonspecific granulomatous dermatoses were included in the study. A panel of histopathological features was blindly evaluated by two independent observers. Only those cases showing nondiagnostic clinicopathological features and lacking demonstrable microorganisms after bacteriological, mycological or mycobacteriological cultures and specific stains (Ziehl-Neelsen, Giemsa, Gram, periodic acid-Schiff stains) were finally selected. Quantitative real-time PCR was performed in all selected samples. In available samples, immunohistochemical detection of specific Leishmania spp. antigens was also performed.
From the selected 25 biopsies, Leishmania spp. DNA was detected by real-time PCR in 13 cases. In seven of eight PCR-positive cases the presence of a varying density of amastigotes could also be demonstrated immunohistochemically.
Leishmania infection seems to be an important aetiological factor in cutaneous granulomatous lesions showing nondiagnostic features in endemic areas. In such areas, Leishmania-specific PCR amplification and/or immunohistochemical studies may be useful diagnostic tools. These techniques may be specifically indicated in the evaluation of patients showing nonspecific granulomatous inflammatory infiltrates of unknown aetiology lacking the histopathological evidence of parasites.
Available from: Claudia Irais Muñoz-García
- "Leishmania spp. DNA was initially investigated with a TaqMan probe rtPCR targeting highly repeated kinetoplast sequences (Mary et al., 2004; Martín-Ezquerra et al., 2009). A subset of DNA from rtPCR-positive samples was further tested with a conventional PCR test amplifying the Leishmania spp. "
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ABSTRACT: Leishmania spp. infection was investigated in tissue samples of wild carnivores from the Spanish Basque Country (BC), by PCR and DNA sequencing. The region is at the northern periphery of L. infantum endemic Iberian Peninsula and infection in the dog (reservoir) or other species has not been previously reported. Leishmania kinetoplast DNA was detected by real-time PCR (rtPCR) in 28% (44/156) of animals. Specifically, in 26% of Eurasian badgers (n = 53), 29% of foxes (n = 48), 29% of stone martens (n = 21) and in 25-50% of less numerous species including genets, wild cats, pole cats, European mink and weasels. Infected animals particularly badgers, were most prevalent in the southernmost province of the BC (Araba) in areas dominated by arable land. Subsequent amplification and sequencing of a fragment of the rRNA internal transcribed spacer 2 (ITS2) from a subset of rtPCR positives samples confirmed the species as L. infantum, showing a high sequence homogeneity with ITS2 sequences of L. infantum from dogs and humans from southern Spain. In summary, this study reports for the first time Leishmania infantum infection in wild carnivores from the BC including in stone martens, pole cats and minks in which infection has not been previously described. It supports the need to study infection in dogs and people in this region and is an example of the value of infection surveillance in wildlife to assess potential risks in the domestic environment and their role in spreading infections in non-endemic areas.
Available from: Godwin Jombo
- "Leishmaniasis has been found to create varying degrees of diagnostic dilemmas in different parts of the world: in Canada, leishmaniasis was found to present as cutaneous myiasis caused by Dermatobia hominis  ; in Tunisia, erythema nodosum was the presenting feature  ; while in Brazil, pyrexia of unknown origin (PUO) were found to be common presentations  . Also in USA, cutaneous leishmaniasis was found to present as sebaceous cysts Table 1 Clinical presentations of cutaneous leishmaniasis in 778 literature reviews on 6 689 cases [n(%)]. "
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ABSTRACT: Cutaneous leishmaniasis is regarded as a re-emerging disease due to its increase in spread and rate of transmission over the past decade due to a proportionate increase in global human movements. This study was therefore carried out to review epidemiology, laboratory diagnosis and treatment with in-depth discussion on some of the rare clinical presentations of the disease capable of influencing its control. The study was based on literature review on clinical and laboratory features of cutaneous leishmaniasis from original research articles, review articles, short communications, letters to editor and case reports on the disease for the past 10 years (April 2000 to April 2010). The results were analysed using simple descriptive methods. The rarest presentations of leishmaniasis encountered were peritibial ulcérations, hard painful nipple in a male, swollen upper lip, dermatofibro sarcoma protuberans, sternal proliferative growth, turban tumour, post operative granuloma, chalazion-like 0.00%, and cutaneous sterile pyogranuloma with asymmetrical alopecia 0.00% each. Others include infected sebaceous cysts 0.45%, syphilis 0.19%, yaws 0.13%, thrombotic ulcérations 0.40%, mycetoma 0.90%, sarcoidosis 0.67%, painless nasal solitary nodule 0.00%, tuberculous lymphadenopathy 0.25% and unilateral erythema nodosum 0.28%. Physicians practicing in cutaneous leishmaniasis endemic, but most especially in the non-endemic areas should bear in mind that the disease may not be that rare in the context of the present global village phenomenon; and that, the next case could just be that of cutaneous leishmaniasis, the clinical picture of the patient notwithstanding.
Available from: Horacio Franco
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ABSTRACT: Previous studies suggest that a hybrid speech recognition system
based on a hidden Markov model (HMM) with a neural network (NN)
subsystem as the estimator of the state conditional observation
probability may have some advantages over the conventional HMMs with
Gaussian mixture models for the observation probabilities. The HMM and
NN modules are typically treated as separate entities in a hybrid
system. This paper, however, suggests that the a priori knowledge of the
HMM structure can be beneficial in the design of the NN subsystem. A
case of isolated word recognition is studied to demonstrate that a
substantially simplified NN can be achieved in a structured HMM by
applying a Bayesian factorization and pre-classification. The results
indicate a similar performance to that obtained with the classical
approach with much less complexity in the NN structure
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