Células gigantes en lepra lepromatosa: dermatitis difusa con células gigantes exuberantes de tipo cuerpo extraño en lepra lepromatosa tratada / Giant cells lepromatous leprosy: Diffuse dermatitis with exuberant foreign body giant cells in treated lepromatous leprosy

Resumen Los pacientes con lepra lepromatosa que han recibido tratamiento durante años, usualmente requieren seguimiento con biopsias de piel para detectar lesiones persistentes o si la baciloscopia es positiva, incluso si los valores son menores que los iniciales. Se presenta el caso de una mujer de 48 años de edad con lepra lepromatosa de 15 años de evolución, índice bacilar de 4 en el extendido directo y en la biopsia, que recibió tratamiento con múltiples medicamentos durante 32 meses, aunque lo recomendado por la Organización Mundial de la Salud (OMS) es una duración de 12 meses. Se tomó una biopsia de piel para determinar si la enfermedad estaba activa. Se observó inflamación dérmica difusa con numerosas células gigantes de tipo cuerpo extraño y macrófagos vacuolados (células de Virchow). Estas células, CD68 positivas, contenían material granular ácido-alcohol resistente positivo con inmunohistoquímica para BCG. Se encontraron bacilos fragmentados y el índice bacilar fue de 2. Se interpretó como una forma residual de lepra lepromatosa y se concluyó que la paciente no requería prolongar el tratamiento con múltiples medicamentos. Este perfil histológico se ha observado en casos similares, pero sin datos clínicos estas biopsias representan un reto diagnóstico. La acumulación de lípidos en estas células gigantes se debe a la destrucción bacilar y a la fusión de macrófagos vacuolados. Se revisó el papel de los lípidos del bacilo y del huésped en la patogenia de la lepra lepromatosa. En estos casos, no es necesario extender los 12 meses de tratamiento con múltiples medicamentos recomendados por la OMS. En el seguimiento de los pacientes, se recomienda contar con los hallazgos clínicos, la baciloscopia, la biopsia anual de piel y los títulos IgM antiglucolípido fenólico.

Abstract Patients with lepromatous leprosy that have received treatment for many years usually get follow up biopsies for persistent skin lesions or positive bacilloscopy even if the values are lower than in the initial bacilloscopy. We report the case of a 48-year old woman with long-standing lepromatous leprosy of 15 years of evolution, with a bacterial index of 4 in the direct smear and the initial skin biopsy. The patient was treated with multidrug therapy for 32 months although the treatment recommended by the World Health Organization (WHO) is only for 12 months. A skin biopsy was taken to determine if there was an active disease. We observed a diffuse dermal inflammation with numerous foreign body giant cells and vacuolated macrophages (Virchow´s cells). These cells contained granular acid-fast material that was also positive with immunohistochemistry for BCG. There were fragmented bacilli and the BI was 2. These cells were also strongly positive for CD68. The biopsy was interpreted as a residual form of lepromatous leprosy that did not require further multidrug therapy. We have observed similar histological profiles in several cases. The lack of clinical data makes it a histological challenge. The accumulation of lipids in these giant cells is due to bacillary destruction and fusion of vacuolated macrophages. We discuss here the role of bacillary and host lipids in the pathogenesis of lepromatous leprosy. We concluded that there was no need to extend the 12-month multidrug therapy recommended by WHO. Clinical findings, bacilloscopy, annual skin biopsy, and anti-phenolic glycolipid-I IgM titers are recommended procedures for the follow-up of these patients.

Association between the Brazilian Breastfeeding Network implementation and breastfeeding indicators / Associação entre a implantação da Rede Amamenta Brasil e indicadores de aleitamento materno

OBJECTIVE: To estimate the association between the implementation of the Brazilian Breastfeeding Network and prevalence of breastfeeding in a medium-size city in southern Brazil. METHODS: This was a cross-sectional study involving 405 children under 1 year who participated in the second phase of the multivaccination campaign in 2012. Children's consumption of food on the day before the interview was obtained through interviews with mothers or guardians. The manager and one health professional from every health facility that joined the Network were interviewed in order to investigate the process of implementation of this initiative. The association between prevalence of breastfeeding and exclusive breastfeeding and adherence to the Network implementation process was tested using Poisson regression with robust variance. RESULTS: Multivariate analysis revealed that among the children assisted by health facilities who joined the Network and those attending services that did not adhere to this strategy, the prevalence of breastfeeding (74% and 70.4% among children under 1 year, respectively) and exclusive breastfeeding (43.3% and 38.1% among children under 6 months, respectively) did not differ significantly. Difficulties in implementing the Network, such as high turnover of professionals, not meeting the criteria for accreditation, and insufficient participation of tutors in the process were identified. CONCLUSION: Contrary to the hypothesis of this study, there was no significant association between the implementation of the Brazilian Breastfeeding Network and prevalence of breastfeeding and exclusive breastfeeding in the studied city. It is possible that the difficulties found in implementing the Network in this city have influenced this result. .

OBJETIVO: Estimar a associação entre a implementação da Rede Amamenta Brasil e as prevalências de aleitamento materno (AM) em um município de médio porte do sul do Brasil. MÉTODOS: Estudo transversal que envolveu 405 crianças menores de um ano que participaram da segunda fase da campanha de multivacinação de 2012. O consumo de alimentos pela criança no dia anterior à entrevista foi obtido mediante entrevistas com as mães ou os responsáveis. Para investigar o processo de implementação da rede foram entrevistados o gerente e um profissional de saúde de cada unidade que aderiu a esse processo. A associação entre as prevalências de AM e AM exclusivo e a adesão ao processo de implementação da rede foi testada com a regressão de Poisson com variância robusta. RESULTADOS: A análise multivariada revelou que entre as crianças assistidas por unidades que aderiram ao processo de implementação da rede e as que frequentam serviços que não aderiram a essa estratégia as prevalências de AM (74% e 70,4% em menores de um ano, respectivamente) e AME (43,3% e 38,1% em menores de seis meses, respectivamente) não diferiram significativamente. Foram identificadas dificuldades na implementação da rede, tais como alta rotatividade dos profissionais, não cumprimento dos critérios para certificação e acompanhamento insuficiente das unidades pelos tutores da rede. CONCLUSÃO: Contrariando a nossa hipótese, não houve associação significativa entre a implementação da Rede Amamenta Brasil e as prevalências de AM e AME no município estudado. É possível que as dificuldades encontradas na implementação da rede nesse município tenham influenciado esse resultado. .

Down-Regulation of Cellulose Synthase Inhibits the Formation of Endocysts in Acanthamoeba

Acanthamoeba cysts are resistant to unfavorable physiological conditions and various disinfectants. Acanthamoeba cysts have 2 walls containing various sugar moieties, and in particular, one third of the inner wall is composed of cellulose. In this study, it has been shown that down-regulation of cellulose synthase by small interfering RNA (siRNA) significantly inhibits the formation of mature Acanthamoeba castellanii cysts. Calcofluor white staining and transmission electron microscopy revealed that siRNA transfected amoeba failed to form an inner wall during encystation and thus are likely to be more vulnerable. In addition, the expression of xylose isomerase, which is involved in cyst wall formation, was not altered in cellulose synthase down-regulated amoeba, indicating that cellulose synthase is a crucial factor for inner wall formation by Acanthamoeba during encystation.

Exposure to cetyl pyridinium chloride and loss of integrity of cell wall of mycobacteria.

Background: Cetyl pyridinium chloride (CPC) liquefied sputum was shown to reduce AFB smear positivity presumably damaging cell wall of M. tuberculosis. Settings: National Institute for Research in Tuberculosis, Chennai, (Tamil Nadu). Objective: To assess the cell wall damage of mycobacteria in CPC liquefied sputum, by Transmission Electron Microscopy (TEM) and mycobacteriophage adsorption studies. Methods: Pooled sputum sample from smear positive pulmonary TB patients was homogenized and liquefied with CPC. It was examined in TEM daily for four days, to assess cell wall damage of M. tuberculosis, and photomicrographs were taken. M. smegmatis mc2155, treated with CPC, was infected with mycobacteriophage (phAE129) to study phage adsorption on cell wall and plaque formation. CPC untreated sputum and M. smegmatis formed controls. Results: Photomicrographs showed that cell wall of M. tuberculosis was intact in controls and damaged in CPC preserved sputum for 96 hours. Plaque formation was seen and absent respectively in CPC untreated and treated M. smegmatis cells. Conclusion: Exposure to CPC damaged the cell wall of M. tuberculosis within 96 hours. Mycobacteriophage failed to form plaques after M. smegmatis mc2155 was treated with CPC implying inhibition of phage adsorption on damaged cell wall and thus providing a clue for poor staining and smear positivity in microscopy.

Kinetic properties of cell wall bound superoxide dismutase in leaves of wheat (Triticum aestivum L.) following stripe rust (Puccinia striiformis) infection.

Stripe rust (Puccinia striiformis f.sp. tritici) is the most devastating disease of wheat (Triticum aestivum L.) accounting huge economical losses to the industry worldwide. HD 2329 was a widely grown wheat cultivar which had become highly susceptible to stripe rust and was used to understand the biochemical aspects of the host pathogen interaction through characterization of superoxide dismutase (SOD). In the present study, two types of SOD, ionically or covalently bound to the particulate fraction were found in the stripe rust infected and uninfected wheat leaves of susceptible cultivar HD 2329. Cell walls of leaves contained a high level of SOD, of which 41-44% was extractable by 2 M NaCl and 10-13% by 0.5% EDTA in infected and uninfected leaves. The NaCl-released SOD constituted the predominant fraction. It exhibited maximum activity at pH 9.0, had a Km value of 1.82-2.51 for uninfected and 1.77-2.37 mM for infected, respectively with pyrogallol as the substrate, and a Vmax of 9.55-21.4 and 12.4-24.1 A min-1g-1FW. A temperature optimum of 20oC was observed for SOD of both uninfected and infected leaves. SOD showed differential response to metal ions, suggesting their distinctive nature. Inhibition of wall bound SOD by iodine and its partial regeneration of activity by mercaptoethanol suggested the involvement of cysteine in active site of the enzyme. These two forms showed greater differences with respect to thermodynamic properties like energy of activation (Ea) and enthalpy change (H), while entropy change (S) and free energy change (G) were similar. The results further showed that pathogen infection of the leaves of susceptible wheat cultivar induced a decrease in the SOD activity and kinetics which might be critical during the response of plant cells to the infection.

The interaction between Histoplasma capsulatum cell wall carbohydrates and host components: relevance in the immunomodulatory role of histoplasmosis

Histoplasma capsulatum is an intracellular fungal pathogen that causes respiratory and systemic disease by proliferating within phagocytic cells. The binding of H. capsulatum to phagocytes may be mediated by the pathogen's cell wall carbohydrates, glucans, which consist of glucose homo and hetero-polymers and whose glycosydic linkage types differ between the yeast and mycelial phases. The ±-1,3-glucan is considered relevant for H. capsulatum virulence, whereas the ²-1,3-glucan is antigenic and participates in the modulation of the host immune response. H. capsulatum cell wall components with lectin-like activity seem to interact with the host cell surface, while host membrane lectin-like receptors can recognize a particular fungal carbohydrate ligand. This review emphasizes the relevance of the main H. capsulatum and host carbohydrate-driven interactions that allow for binding and internalization of the fungal cell into phagocytes and its subsequent avoidance of intracellular elimination.

Phenotypic switching and its influence on expression of virulence factors by Candida albicans causing candidiasis in human immunodeficiency virus-infected patients.

PURPOSE: The purpose of the present study was to determine the degree of expression of virulence factors such as adherence, cell surface hydrophobicity (CSH) and production of proteinase by different morphological forms of Candida albicans causing oral candidiasis in human immunodeficiency virus (HIV)-infected individuals. METHODS: C. albicans 3153A and two strains isolated from oral thrush in HIV infected individuals were induced to undergo phenotypic switching by exposure to UV light and the degree of expression of virulence factors by the different morphological forms was studied. RESULTS: Three different morphological forms of C. albicans were obtained namely, star (S), wrinkled (W) and ring (R) types from the original smooth (O) variety. It was found that proteinase production was greatest with the W type followed by the R type and O type. The S type produced the least proteinase. Expression of cell surface hydrophobicity and adherence was greatest in the O type followed by the R and then the W type and finally the S type. CONCLUSIONS: The differential expression of virulence factors occurs with different phenotypic forms of C. albicans and this may provide a particular morphological type with a distinct advantage over other types in causing candidiasis.

Cytochemical localization of acid phosphatase in Stigeoclonium tenue (Chaetophorales, Chlorophyceae)

Nonspecific acid phosphatases are a group of enzymes whose activity increases the availability of exogenous and endogenous orthophosphate either through extra- or intracellular hydrolysis of phosphate compounds. Our study demonstrates the activity of acid phosphatases in the filamentous freshwater alga Stigeoclonium tenue. These enzymes were detected following a cerium-based method in which cerium was used as an orthophosphate-capture reagent. In thalli from S. tenue from the natural environment, acid phosphatases were found in the longitudinal cell wall,plasmalemma, and vacuole. In thalli from Bold's Basal Medium culture, these enzymes were found mainly in the plasmalemma; they were scarce in the cell wall. In the thalli grown in phosphate-enriched culture medium, enzymes were found only in the plasmalemma. The low availability of orthophosphate in the medium seems to induce the transport of these enzymes to the cell wall. Its abundance, on the contrary, seems to attenuate this response without affecting the localization of acid phosphatases in the plasmalemma.

The cell wall of Paracoccidioides brasiliensis: insights from its transcriptome

The cell wall of a human pathogenic fungus is in contact with the host, serves as a barrier against host defense mechanisms and harbors most fungal antigens. In addition, cell wall biosynthesis pathways have been recognized as essential to viability and as specific drug targets. Paracoccidioides brasiliensis is a dimorphic fungus that presents mycelium morphology in the free environment and causes infection in a yeast form. The morphogenetic conversion is correlated with changes in the cell wall composition, organization and structure. Based on transcriptome analysis, the enzymes involved in the biosynthesis and remodeling of cell wall polysaccharides, as well as several cell wall-associated molecules of P. brasiliensis, were identified and addressed in further detail.

Chemical components of heartwood and sapwood of common Yew (Taxus baccata L.).

Cell-wall components and solubility characteristics of the heartwood and sapwood of Taxus baccata L. were determined by methods of wood analysis and the differences between heartwood and sapwood were established. When we observe the data obtained, it is seen that the amount of extractive material found in the heartwood is substantially higher than the sapwood. The extractive material in Taxus baccata L. is originated from the hidden epithelial cells surrounded by resin canals.

Distribution of pectins in the pollen apertures of Oenothera hookeri: velans ster/+ster

Cell wall pectins are some of the most complex biopolymers known, and yet their functions remain largely mysterious. The aim of this paper was to deepen the study of the spatial pattern of pectin distribution in the aperture of Oenothera hookeri.velans ster/+ster fertile pollen. We used "in situ" immunocytochemical techniques at electron microscopy, involving monoclonal antibodies JIM5 and JIM7 directed against pectin epitopes in fertile pollen grains of Oenothera hookeri.velans ster/+ster. The same region was also analyzed by classical cytochemistry for polysaccharide detection. Immunogold labelling at the JIM7 epitope showed only in mature pollen labelling mainly located at the intine endo-aperture region. Cytoplasmic structures near the plasma membrane of the vegetative cell showed no labelling gold grains. In the same pollen stge the labelling at the JIM5 epitope was mostly confined to a layer located in the limit between the endexine and the ektexine at the level of the border of the oncus. Some tubuli at the base of the ektexine showed also an accumulation of gold particles. No JIM5 label was demonstrated in the aperture chamber and either in any cytoplasmic structure of the pollen grains. The immunocytochemical technique, when compared with the traditional methods for non-cellulose polysaccharide cytochemistry is fare more sensitive and allows the univocal determination of temporal and spatial location of pectins recognized by the JIM7 and JIM5 MAbs.

A new streptomycete producing diphenyl sulfone antibiotic--S. sulfonensis.

About 359 actinomycetes were isolated from 8 different natural substrates collected from different parts of Andhra Pradesh. The isolates were screened on the basis of their inhibitory effect against test organisms. Finally one potent antibiotic producer was chosen having broad-spectrum activity against Gram-positive and Gram-negative bacteria and it was found to produce a diphenyl sulfone antibiotic. On the basis of morphological, cultural, physiological and biochemical characters, the diphenyl sulfone antibiotic producer was identified as a new species and was designated as S. sulfonensis.

Isolation and characterization of a copper containing protein from blue cell walls of Neurospora crassa.

Culturing Neurospora crassa in presence of toxic amounts of copper (0.63 mM) resulted in blue coloured mycelia and cell walls. Significant amounts (approximately 45%) of total mycelial copper were associated with cell wall isolates under conditions of copper toxicity. Hence, such blue cell walls were analysed to identify specific ligands involved in copper binding. While decuprification of the blue cell walls with 8-hydroxy quinoline (8 HQ) did not alter their copper binding abilities, similar treatment with EDTA (10 mM) decreased such abilities indicating that EDTA treatment lead to loss of copper binding ligands from cell walls. Treatment of blue cell walls with 8 HQ followed by EDTA resulted in the solubilization of a copper binding protein (relative MW approximately 14 kDa) which was associated with phosphate and carbohydrate moieties. On amino acid analysis, this protein was found to be devoid of free thiol groupings but enriched in acidic and basic amino acids, distinguishing it from classical intracellular metal binding proteins such as metallo-thioneins and phytochelatins that are inducively synthesized under conditions of metal toxicity. The biological significance of the isolated wall-bound copper binding protein, which appears to be a normal constituent of cell walls, is discussed in relation to cytoplasmic metal binding proteins and mechanism(s) adapted by fungi in countering metal toxicity.

Purificaçäo da parede celular de microorganismos da placa dental / Purification of the cellular wall of dental plaque microorganisms

Estabeleceu-se uma metodologia para purificaçäo da parede celular de microorganismos da placa dental. O material purificado tornou-se um agente flogógeno útil em modelos de estudo de reaçöes inflamatórias agudas crônicas

Los hongos dimorficos: aproximacion bioquimica a su dimorfismo / Dimorphic fungi: biochemical approach to their dimorphism

Dimorphism in pathogenic fungi is reviewed. The phenomenon is divided into four interwoven events: (a) perception of external stimuli by cellular sensors; (b) translation into a biochemical message; (c) alteration of the genomic expression, and (d) structural reorganization towards the morphological change. Experimental evidence is provided. Finally, the possibility that fungal dimorphism may have arisen multiple times throughout evolution, is discussed

On structural aspects of peptidoglycan of bacterial cell wall with special attention on mycobacteria by computer modelling.

The cell wall components of mycobacteria are said to be vitally linked with their pathogenicity. Peptidoglycan, one of the major cell wall component in most of the bacteria are multilayered in gram positive bacteria and it is diverse in nature for the Gram positive strain rather than gram negative. The cell wall of bacteria are primary targets for many drugs and antibiotics and conformation of the major cell wall components provide invaluable information and understanding at molecular level to medicinal chemists and drug designers. Mycobacterial peptidoglycan has been studied critically by computer modelling on various aspects. A plausible structure and conformation has been identified and glycan chain is found to have a pseudo two fold symmetry taking disaccharide unit as monomer with Knox & Murthy H-bond scheme. This paper attempts to clarify the understanding of organisation and possible interaction mode of peptidoglycan of organisation in complex mycobacterial cell wall structure.