Stromal vascular fraction cell sheets angiogenic potential for tissue engineering and regenerative medicine applications

One of the biggest concerns in the Tissue Engineering field is the correct vascularization of engineered constructs. Strategies involving the use of endothelial cells are promising but adequate cell sourcing and neo-vessels stability are enduring challenges. In this work, we propose the hypoxic pre-conditioning of the stromal vascular fraction (SVF) of human adipose tissue to obtain highly angiogenic cell sheets (CS). For that, SVF was isolated after enzymatic dissociation of adipose tissue and cultured until CS formation in normoxic (pO2=21%) and hypoxic (pO2=5%) conditions for 5 and 8 days, in basal medium. Immunocytochemistry against CD31 and CD146 revealed the presence of highly branched capillary-like structures, which were far more complex for hypoxia. ELISA quantification showed increased VEGF and TIMP-1 secretion in hypoxia for 8 days of culture. In a Matrigel assay, the formation of capillary-like structures by endothelial cells was more prominent when cultured in conditioned medium recovered from the cultures in hypoxia. The same conditioned medium increased the migration of adipose stromal cells in a scratch assay, when compared with the medium from normoxia. Histological analysis after implantation of 8 days normoxic- and hypoxic-conditioned SVF CS in a hindlimb ischemia murine model showed improved formation of neo-blood vessels. Furthermore, Laser Doppler results demonstrated that the blood perfusion of the injured limb after 30 days was enhanced for the hypoxic CS group. Overall, these results suggest that SVF CS created under hypoxia can be used as functional vascularization units for tissue engineering and regenerative medicine.

Effect of fetal bovine serum on Candida glabrata cultures

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Engenharia Clínica)

Mediastinitis after cardiac transplantation

OBJECTIVE: Assessment of incidence and behavior of mediastinitis after cardiac transplantation. METHODS: From 1985 to 1999, 214 cardiac transplantations were performed, 12 (5.6%) of the transplanted patients developed confirmed mediastinitis. Patient's ages ranged from 42 to 66 years (mean of 52.3±10.0 years) and 10 (83.3%) patients were males. Seven (58.3%) patients showed sternal stability on palpation, 4 (33.3%) patients had pleural empyema, and 2 (16.7%) patients did not show purulent secretion draining through the wound. RESULTS: Staphylococcus aureus was the infectious agent identified in the wound secretion or in the mediastinum, or both, in 8 (66.7%) patients. Staphylococcus epidermidis was identified in 2 (16.7%) patients, Enterococcus faecalis in 1 (8.3%) patient, and the cause of mediastinitis could not be determined in 1 (8.3%) patient. Surgical treatment was performed on an emergency basis, and the extension of the débridement varied with local conditions. In 2 (16.7%) patients, we chose to leave the surgical wound open and performed daily dressings with granulated sugar. Total sternal resection was performed in only 1 (8.3%) patient. Out of this series, 5 (41.7%) patients died, and the causes of death were related to the infection. Autopsy revealed persistence of mediastinitis in 1 (8.3%) patient. CONCLUSION: Promptness in diagnosing mediastinitis and precocious surgical drainage have changed the natural evolution of this disease. Nevertheless, observance of the basic precepts of prophylaxis of infection is still the best way to treat mediastinitis.

Effect of pH on Candida tropicalis virulence factors

Dissertação de mestrado em Bioengenharia

Interacciones inmuno-endócrinas: participación de tlr-4 y citoquinas pro-inflamatorias en la regulación de la proliferación de células lactotropas. Immuno-endocrine interactions: Contribution of tlr-4 and pro-inflammatory cytokines in the regulation of lactotroph cell proliferation.

El presente proyecto tiene como objetivo estudiar, a nivel celular y molecular, los mecanismos inmuno-endócrinos que participan en la proliferación de células lactotropas normales y tumorales frente a procesos inflamatorios inducidos experimentalmente. Una particular atención se pondrá al evaluar la contribución de IL-6 como citoquina intrahipofisaria durante el desarrollo tumoral y su rol como señal paracrina/autocrina en la senescencia hipofisaria. Debido a que agentes inflamatorios y anti-inflamatorios pueden inducir alteraciones en el crecimiento y la función hipofisaria, no se descartaría que, en el curso de una inflamación, como la inducida por el lipopolisacárido bacteriano LPS, puedan ocurrir modificaciones en el índice proliferativo de las células lactotropas y/o en la secreción de su producto hormonal, la prolactina. Dado el auge en las investigaciones referidas al campo de la modulación inmuno-endócrina, es que planteamos investigar la participación de TLR4, componente crucial del complejo proteico que inicia la señal LPS, en hipófisis normales y tumorales inducidas por estrógeno así como también en la línea celular somatolactotrópica GH3B6. Dentro de las vías de transducción de señales involucradas se determinará la participación de MAPK-ERK1/2 y de PI3K asi como la contribución de NF-kB en la regulación del crecimiento celular inducido por IL-6/LPS mediante el uso de inhibidores específicos. La microscopía electrónica y confocal, resultarán de fundamental importancia para valorar los procesos de translocación nuclear de NF-kB como así también para definir la localización ultraestructural de los mediadores mencionados. Además, se valorará el mecanismo de senescencia celular hipofisaria mediante parámetros morfológicos, bioquímicos y ultraestructurales durante el desarrollo de prolactinomas inducidos experimentalmente. Finalmente dilucidar las posibles vías de transducción de señales que se desencadenan frente a estímulos inflamatorios/proliferativos podría explicar algunos aspectos moleculares sobre la función de control del ciclo celular y las limitaciones de crecimiento en adenomas hipofisarios que subyacen en la falta de progresión de estos tumores a la malignidad. The aim of the present project is to study the immuno-endocrine mechanisms involved in the proliferation of normal and tumoral lactotrophs experimentally induced by inflammatory factors. Also, the contribution of IL-6 as a paracrine / autocrine signal in the pituitary senescence will be assessed along tumor development induced by estrogen treatment. Considering that both, inflammatory and anti-inflammatory agents can modify the pituitary function, it is possible that in the course of inflammation, as induced by bacterial lipopolysaccharide LPS, some alteration may occur in the proliferative index of lactotrophs and / or in the PRL secretion. Our main objective is to investigate the cellular and molecular mechanisms involved by the activation of TLR4, a crucial component of the protein complex initiated by LPS, in normal and pathological pituitaries induced by estrogen as well as in the GH3B6 cell line. The participation of MAPK-ERK1 / 2 and PI3K signaling pathway and the contribution of NF-kB in the proliferative responses triggered by IL-6/LPS will be analyzed by using specific inhibitors. Confocal microscopy analysis is essential to assess the process of nuclear translocation of NF-kB as well as the use of electron microscopy to define the ultrastructural localization of the above mentioned mediators. In addition, the mechanisms of pituitary cell senescence will be evaluated through morphological, biochemical and ultrastructural approaches during the development of experimental prolactinomas. Finally, the elucidation of possible signal transduction pathways which are triggered by inflammatory / proliferative stimuli, would explain some molecular aspects of cell cycle control and limitations in pituitary tumor growth that underlie the lack of progress in these pituitary tumors to malignancy.

Einfluss von Proteasominhibitoren auf die Chemokinsekretion von Lungenepithelzellen und myeloischen Zellen

Proteasome inhibitors, lung epithelial cells, myeloid cells, IL-8-secretion, cell cycle arrest, suppression of proliferation, transcription factors NF-kB and AP-1, neutrophil chemotaxis assay

Molekulare Mechanismen der Helicobacter pylori-Infektion : Rolle von gastrischen Epithelzellen und Granulozyten

Helicobacter pylori; pathogenicity factors; type IV secretion; AGS cells; PMNs; real time PCR; interleukin-8; toll-like receptors

Anatomia, dos nectános de algumas espécies da flora apícola

This paper deals with anatomical descriptions of some types of nectaries in 27 species of honey plants of Piracicaba, S. P. The material studied was divides in two groups: a) Extra-floral nectaries; b) Floral nectaries. Euphorbia pulcherrima, Willd; showed to belonging to the first group: its nectaries tissue consist of an epidermal layer of cell without stomata and with true gland, with subepidermal cells diferentiated by the thickness of the wall. Among the plants with floral nectaries, the following types has been listed, according the location of the nectary in the flower: 1 - with true glands: a) in sepals, Hibiscus rosa sinensis, L.; Dombeya Wallichii, Bth. e Hk; b) in the stamens tube, Antigonum leptopus, Hook e Arn.; 2 - on the receptacle with nectariferous tissue in the epidermal cell with: a) thickness wall with stomata, Prunus persical, L.; b) thin wall without stomata, Crotalaria paulinia, Shranck; Caesal-pinia sepiaria, Roxb; Aberia caffra; 3 - with a disc located in the receptacle with: epidermal: a) with stomata, Coffea arábica, L. var. semper florens; Citrus aurantifolia, Swing; Cinchona sp.; Pryrostegia ignea, Presl.; b) without stomata and with thin wall, Leojurus sibiricus, L.; Bactocydia unguis, Mart., Ipomoea purpurea, L.; Greviüea Thelemanniana, Hueg.; Dolichos lablab, L.; Vernonia polyanthes, Less., Montanoa bipinatifida, C. Koch., Eruca sativa, L. Brassica Juncea, Co; Eucalyptus tereticomis, Smith.; Eucalyptus rostrata, Schleche; Salvia splendens, Selow.; 4 - in the basal tissues of the ovary, Budleia brasiliensis, Jacq F.; Petrea subserrata, Cham.; 5 - in the base of stamens, Per sea americana, Mill. On the anatomical point of view, most of the types of nectary studied has external nectariferous tissues, located on the epidermal cells with thin periclinal wall and without stomata. The sub-epidermal layer were rich in sugar. Short correlation was found between the structure of the nectary and the amount of nectar secretion. So, in the nectary with true glands, in those with thin wall and without stomata on epidermal cells and in those with stomata, the secretion was higher than in the other types listed.

Ultraestructura de los acinos sudoríparos de las glándulas pelvianas de Chaetophractus villosus (Mammalia, Dasypodidae)

The acini of pelvian glands of Chaetophractus villosus (Desmarest, 1804) consisted of an inner layer of secretory cells and an outer layer of myoepithelial cells. Secretory cells have numerous secretory vacuoles. The secretion is released by exocytosis. Myoepithelial cells have numerous myofilaments that occupy much of the cytoplasm. There is a third cell type with an extremely electron-lucent cytoplasm.

Ultra-estrutura de glândulas abdominais tegumentares em Oxaea flavescens (Hymenoptera, Andrenidae, Oxaeinae)

The sternal glands of the abdomen of Oxaea flavescens (Klug, 1807) consist of class III glandular cells around a reservoir constituted by branched folds of the intersegmental membrane of segments III, IV and V. The gland cells are rich in rough endoplasmic reticulum and produce a secretion with mucous aspect. The treatment with oxidated osmium and ruthenium red showed numerous Golgi regions in the cell and carbohydrates absorption from the haemolymph, respectively. The high degree of development of the glands suggests an important function to the species, although still unknown.

Histologia del sistema reproductor masculino de Helobdella hyalina (Hirudinea, Glossiphoniidae) en Argentina

A detailed preliminary histological analysis of Helobdella hyalina Ringuelet, 1942 male system from Los Talas, Buenos Aires, Argentina is described. Six pairs of testisacs, located between the crop caeca, form the male reproductive system. Each testisac is clothed by the mesotelium. Inside it, the germinal cells are connected to the citophore and develop functional unit called poliplast. The spermatozoa are released into testisacs after the reabsortion of the citophore. Five stages of spermatogenesis are described taking into account the successive maturation stages of germinal cells and the changes in the citophore size. Lining cells and gland cells were found in the seminal vesicle. Five different types of gland cells are placed inside the ejaculatory ducts, as well as two kinds of cells are found in its distal portion: type 1, which produces eosinophilic granular secretion, type 2, with amorphous and slightly eosinophilic. Three distinct gland cells are located in the proximal portion of the duct: type 3, which produces a strongly eosinophilic granular secretion; type 4, with a negative eosinophilic amorphous secretion and type 5, with a basophilic granular secretion. Type 5 gland cells are described for the ducts of this species only.

Metanotal gland of the genus Eidmanacris (Grylloidea, Phalangopsidae): taxonomic importance

The present study compares the metanotal gland through scanning electron microscopy in five species of Eidmanacris: E. corumbatai Garcia, 1998, E. alboannulata (Piza, 1960), E. dissimilis Desutter-Grandcolas, 1995, E. larvaeformis (Chopard, 1938) and Eidmanacris sp. The general external configuration of the gland was determined by the presence of two median projections with apical opening and a cluster of bristles just above these projections. Although there is a general pattern for this gland, each species has its own pattern, which can be defined mainly by the arrangement of the bristles and the position of the median projections. Our results suggest the taxonomical importance of these structures, which should be better analyzed when describing species of the genus Eidmanacris. In addition, while observing the reproductive behavior of these species, we concluded that the release of this gland secretion is important for the success of mating.

Influence of mucin on the metabolism of pnemococcus

1. The appearance of meta-hemoglobin in pneumococcus cultures in blood media must be consequential to the formation of hydogen peroxide, according to the observation of several authors as well as of our own. 2. We emphasize the rôle of mucin in the production of hydrogen peroxide by pneumococcus, a circumstance which has been neglected by the authors who dealt with the matter. 3. In the metabolism of pneumococcus, the existence or formation of mucin is necessary for the maintenance of certain biological properties of the germ. 4. In cultures media containing blood and mucin, the production of meta-hemoglobin by pneumococcus is much larger than in those which contain no mucin. 5. We venture the hypothesis that mucin plays a very important rôle in the implantation of pneumonia, as in the periods preceeding this disease theres is an increase of bronchial secretion, and this secretion is almost entirely constintuted by mucin. 6. Mucin increases the pathogenic power of pneumococcus in mice according to the studies of several authors, which comes to favour our hypothesis.

Contribution to the normal fecal flora of the hamster: Proteus mirabilis in normal feces of hamster

Proteus mirabilis must be considered a normal inhabitant of the intestine of hamsters. It is also found in the vaginal secretion of females of this animal, when in oestrus.