Unusual morphologies of Cryptococcus spp. in tissue specimens: report of 10 cases

Ten cases of cryptococcosis due to unusual microscopic forms of Cryptococcus sp. observed over a twenty-eight year period (1981-2009) are presented. The most important clinicopathological and laboratory data are tabulated. The uncommon forms of cryptococcal cells given are: structures resembling germ tube (one case), chains of budding yeasts (one case), pseudohyphae (two cases) and nonencapsulated yeast-like organisms (eight cases). The diagnosis was based on the histopathological findings. The causative organism was isolated and identified in seven cases; five were due to C. neoformans, and two to C. gattii. In addition, the importance of using staining histochemical techniques - Grocott's silver stain (GMS), Mayer's mucicarmine stain (MM) and Fontana-Masson stain (FM) - in the diagnosis of cryptococcosis is argued.

Thoracic Manifestations of Connective Tissue Diseases

Connective tissue diseases (CTDs) comprise several immunologic systemic disorders, each of which associated with a particular set of clinical manifestations and autoimmune profile. CTDs may cause numerous thoracic abnormalities, which vary in frequency and pattern according to the underlying disorder. The CTDs that most commonly involve the respiratory system are progressive systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, Sjögren syndrome, polymyositis, dermatomyositis, and mixed connective tissue disease. Pulmonary abnormalities in this group of patients may result from CTD-related lung disease or treatment complications, namely drug toxicity and opportunistic infections. The most important thoracic manifestations of CTDs are interstitial lung disease and pulmonary arterial hypertension, with nonspecific interstitial pneumonia being the most common pattern of interstitial lung disease. High-resolution computed tomography is a valuable tool in the initial evaluation and follow-up of patients with CTDs. As such, general knowledge of the most common high-resolution computed tomographic features of CTD-related lung disease allows the radiologist to contribute to better patient management.

Trypanosomiasis cruzi: a follow-up study of tissue reacting immunoglobulins in infected purebred pinscher dogs

Antibodies against striated muscle (cardiac and skeletal) were studied in serum samples from 36 purebred prepubertal Pinscher dogs (15 Controls without infection and 21 infected with Trypanosoma cruzi from 7 to 400 days after infection with 1000 trypomastigotes/gram body weight of the Colombiana strain by the intraperitoneal route). Although three different immunohistological pattems of tissue-reacting immunoglobulins were found their presence was not correlated with any peculiar characteristics or with the severity of the disease in each particular dog.

The Role of Actin-Capping Protein and Src signalling in tissue growth and apoptosis during Drosophila wing development

Dissertation presented to obtain the Ph.D degree in Developmental Biology

Protest attitudes and stated preferences: Evidence on scale usage heterogeneity

We contribute to the stated preference literature by addressing scale usage heterogeneity regarding how individuals answer attitudinal questions capturing lack of trust in institutions and fairness issues. Using a latent class model, we conduct a contingent valuation study to elicit the willingness-to-pay to preserve a recreational site. We find evidence that respondents within the same class, that is, with similar preferences and attitudes, interpret the Likert scale differently when answering the attitudinal questions. We identify different patterns of scale usage heterogeneity within and across classes and associate them with individual characteristics. Our approach contributes to better a understanding of individual behavior in the presence of protest attitudes.

South American rattlesnake bite and soft-tissue infection: report of a case

The case of a man bitten by a South American rattlesnake (Crotalus durissus) and who developed an abscess at the site of the bite is reported. Abcesses are a rare complication of this type of envenoming, possibly due to the lack of a strong cytotoxic action of Crotalus durissus venom.

Clonal structure of Trypanosoma cruzi Colombian strain (biodeme Type III): biological, isoenzymic and histopathological analysis of seven isolated clones

The clonal structure of the Colombian strain of Trypanosoma cruzi, biodeme Type III and zymodeme 1, was analyzed in order to characterize its populations and to establish its homogeneity or heterogeneity. Seven isolated clones presented the basic characteristics of Biodeme Type III, with the same patterns of parasitemic curves, tissue tropism to skeletal muscle and myocardium, high pathogenicity with extensive necrotic-inflammatory lesions from the 20th to 30th day of infection. The parental strain and its clones C1, C3, C4 and C6, determined the higher levels of parasitemia, 20 to 30 days of infection, with high mortality rate up to 30 days (79 to 100%); clones C2, C5 and C7 presented lower levels of parasitemia, with low mortality rates (7.6 to 23%). Isoenzymic patterns, characteristic of zymodeme 1, (Z1) were similar for the parental strain and its seven clones. Results point to a phenotypic homogeneity of the clones isolated from the Colombian strain and suggest the predominance of a principal clone, responsible for the biological behavior of the parental strain and clones.

The role of Grainy head in epithelial tissue growth

Part of the results of this thesis was presented in the following meetings: Susana Ponte, Lara Carvalho, Inês Cristo and António Jacinto. The role of Grainy head in epithelial tissue growth. Drostuga 2013. Faro, Portugal, January 3rd 2014 [poster] Susana Ponte, Lara Carvalho, Inês Cristo and António Jacinto. The role of Grainy head in epithelial tissue growth. Drostuga 2014. Tomar, Portugal, September 5th-6th 2014 [poster]

Proteomics based approach to understand tissue regeneration

Dissertation presented to obtain the PhD degree in Biochemistry

Hydroxyapatite porous structures for bone tissue engineering

Esta dissertação teve como objetivo o desenvolvimento de espumas porosas de hidroxiapatite (HA) baseadas em réplicas invertidas de cristais coloidais (ICC) para substituição óssea. Um ICC é uma estrutura tridimensional de elevada porosidade que apresenta uma rede interconectada de poros com elevada uniformidade de tamanhos. Este tipo de arquitetura possibilita uma proliferação celular homogénea e superiores propriedades mecânicas quando comparada com espumas de geometria não uniforme. O cristal coloidal (CC) - o molde da espuma - foi criado por empacotamento de microesferas de poliestireno (270 μm) produzidas por microfluídica e posterior tratamento térmico. O molde foi impregnado com um gel de hidroxiapatite produzido via sol-gel utilizando pentóxido de fósforo e nitrato de cálcio tetrahidratado como percursores de fósforo e cálcio, respectivamente. A espuma cerâmica foi obtida num único passo depois de um tratamento térmico a 1100oC que permitiu a solidificação do gel e a remoção do CC. A análise por espetroscopia de infravermelho por transformada de Fourier (FTIR) e difração de raios-X (XRD) revelou uma hidroxiapatite carbonatada tipo A com presença de fosfatos tricálcicos. As propriedades mecânicas foram avaliadas por testes de compressão. A biocompatibilidade in vitro foi demonstrada através de testes de adesão e proliferação celular de osteoblastos.

A semi-nested PCR assay for molecular detection of Paracoccidioides brasiliensis in tissue samples

INTRODUCTION: Paracoccidioidomycosis is a systemic infection caused by Paracoccidioides brasiliensis. METHODS: In this study, a semi-nested PCR for paracoccidioidomycosis diagnosis was developed. The primers ITS1 and ITS4 were used in the first reaction, while the primers MJ03 and ITS1 primer were used in the second reaction. The semi-nested PCR was used to investigate biopsies of five patients with oral lesions that resembled paracoccidioidomycosis. RESULTS: The semi-nested PCR was positive for four samples and negative for a sample from a patient later diagnosed with leishmaniasis. CONCLUSIONS: The new semi-nested PCR describe is useful for paracoccidioidomycosis diagnosis.

Tissue expander complications in plastic surgery: a 10-year experience

INTRODUCTION: Tissue expanders have been of great value in plastic surgery. Tissue expansion was developed for a specific indication; however, within a very short time, the concept of tissue expansion found wide applicability. From 1990 to 1999, 315 expanders in 164 patients were utilized. A retrospective analysis of complications and prognostic factors for complications were done. METHODS: The indications for tissue expansion were burns (50%), trauma (32%), and sequelae of previous surgery (8.8%). The expanders were inserted most frequently in the scalp, trunk and neck. RESULTS: There were 22.2% of complications and the most common were expander exposure (50%), infection (24%) and bad function of the expander (12.8%). The present study revealed an increased rate of minor complications in the group of 0 to 10 years of age and an increased rate of major complications for face and neck expansions compared to trunk expansion. There were no increased complication rates for the other age and anatomic site groups, previous expansion, concomitant expansion and type of expander used. CONCLUSIONS: The outcomes from tissue expansion procedures done in our hospital are similar to those reported in the literature. Tissue expansion is a good and safe technique.

The effect of the presence of muscle tissue in a bone healing site

PURPOSE: The recovery of a bone fracture is a process that is not yet fully understood. The literature conflicts on the results obtained by the interposition of foreign tissue inside a damaged bone. The objective of the present study was to ascertain the effect of placing muscle tissue between the stumps of a fractured bone. METHOD: The study was carried out on 10 rabbits divided into 2 groups (n = 5): Group 1-partial fracture of the humerus and interposition of muscle tissue; Group 2-complete fracture of the humerus and interposition of muscle tissue. The fractured limb of all animals was immobilized for 8 weeks. At the end of this time, the rabbits were killed and their operated humeri were carefully removed for roentgenological and histological assessment. RESULTS: All humeri of Group 1 recovered their integrity and normal aspect. However, the healing of the humeri of Group 2 was not perfect. Gross angulation of the bone diaphysis occurred in all animals, and immature trabecular bone, osteochondral tissue, and persistence of muscle tissue substituted normal bone. CONCLUSIONS: Interposed muscle does not affect partial bone fracture healing but causes instability in a complete fracture.

Endemic pemphigus foliaceus (fogo selvagem) and pemphigus vulgaris: immunoglobulin G heterogeneity detected by indirect immunofluorescence

Pemphigus are autoimmune intraepidermal blistering diseases in which immunoglobulin G (IgG) autoantibodies are directed against desmosomal glycoproteins. The aim of this study was to determine the IgG subclass profile of endemic pemphigus foliaceus (fogo selvagem) and pemphigus vulgaris utilizing indirect immunofluorescence. PATIENTS AND METHODS: Twenty-five patients with pemphigus vulgaris, 25 with endemic pemphigus foliaceus (fogo selvagem), and 25 healthy controls were analyzed by indirect immunofluorescence for circulating autoantibodies (total IgG and its subclasses). RESULTS: Our data revealed a significant correlation (P <.05) of disease activity and autoantibody levels in both forms of pemphigus, i.e., negative titers related to clinical remission, whereas positive results related to active disease. Immunoglobulin G subclass analysis in fogo selvagem demonstrated that in patients in remission, 56% showed positive immunoglobulin G4; in active disease, immunoglobulin G4 was the predominant subclass (100% positive in all cases). The IgG subclass profile in pemphigus vulgaris showed that in patients in remission, only 10% were positive for immunoglobulin G4; in active disease, positivity for immunoglobulin G4 was present in 78% to 88% of the cases. CONCLUSION: Subclass characterization of immunoglobulin G autoantibodies is a useful tool for pemphigus follow-up, since immunoglobulin G4 (IgG4) is the subclass that is closely related to recognition of pathogenic epitopes, and consequently with disease activity. Careful monitoring should be performed for fogo selvagem in clinical remission with a homogeneous IgG4 response, since this may indicate more frequent relapses.