Hind limb ischemia in type 1 diabetic mice as useful tool to evaluate the neovascularization of tissue engineering constructs

Hind-limb ischemia has been used in type 1 diabetic mice to evaluate treatments for peripheral arterial disease or mechanisms of vascular impairment in diabetes [1]. Vascular deficiency is not only a pathophysiological condition, but also an obvious circumstance in tissue regeneration and in tissue engineering and regenerative medicine (TERM) strategies. We performed a pilot experiment of hind-limb ischemia in streptozotocin(STZ)-induced type 1 diabetic mice to hypothesise whether diabetes influences neovascularization induced by biomaterials. The dependent variables included blood flow and markers of arteriogenesis and angiogenesis. Type 1 diabetes was induced in 8-week-old C57BL/6 mice by an i.p. injection of STZ (50 mg/kg daily for 5 days). Hind-limb ischemia was created under deep anaesthesia and the left femoral artery and vein were isolated, ligated, and excised. The contralateral hind limb served as an internal control within each mouse. Non-diabetic ischaemic mice were used as experiment controls. At the hind-limb ischemia surgical procedure, different types of biomaterials were placed in the blood vessels gap. Blood flow was estimated by Laser Doppler perfusion imager, right after surgery and then weekly. After 28 days of implantation, surrounding muscle was excised and evaluated by histological analysis for arteriogenesis and angiogenesis. The results showed that implanted biomaterials were promote faster restoration of blood flow in the ischemic limbs and improved neovascularization in the diabetic mice. Therefore, we herein demonstrate that the combined model of hind-limb ischemia in type 1 diabetes mice is suitable to evaluate the neovascularization potential of biomaterials and eventually tissue engineering constructs.  

Development of advanced cell/tissue culture systems, based on enhanced polymeric scaffolds and sophisticated bioreactors, for tissue engineering applications

Programa Doutoral em Engenharia Biomédica

Possibilidades de reabilitação urbana em bairros sociais: estudo de caso: Bairro Social de Santa Tecla, Braga

Dissertação de mestrado integrado em Engenharia Civil

Semipermeable capsules wrapping a multifunctional and self-regulated co-culture microenvironment for osteogenic differentiation

A new concept of semipermeable reservoirs containing co-cultures of cells and supporting microparticles is presented, inspired by the multi-phenotypic cellular environment of bone. Based on the deconstruction of the â stem cell nicheâ , the developed capsules are designed to drive a self-regulated osteogenesis. PLLA microparticles functionalized with collagen I, and a co-culture of adipose stem (ASCs) and endothelial (ECs) cells are immobilized in spherical liquified capsules. The capsules are coated with multilayers of poly(L-lysine), alginate, and chitosan nano-assembled through layer-by-layer. Capsules encapsulating ASCs alone or in a co-culture with ECs are cultured in endothelial medium with or without osteogenic differentiation factors. Results show that osteogenesis is enhanced by the co-encapsulation, which occurs even in the absence of differentiation factors. These findings are supported by an increased ALP activity and matrix mineralization, osteopontin detection, and the up regulation of BMP-2, RUNX2 and BSP. The liquified co-capsules also act as a VEGF and BMP-2 cytokines release system. The proposed liquified capsules might be a valuable injectable self-regulated system for bone regeneration employing highly translational cell sources.

Valorização patrimonial e urbana de Braga através da criação de circuitos turísticos

Projeto de mestrado em Património e Turismo Cultural

Plano de revitalização do centro histórico de Braga

Dissertação de mestrado em Políticas Comunitárias e Cooperação Territorial

Biomedical applications of human cathelicidin

[Excerpt] Antimicrobial peptides (AMPs) are good candidates to treat burn wounds, a major cause of morbidity, impaired life quality and resources consumption in developed countries. Tuberculosis (TB), a disease caused by the human pathogen Mycobacterium tuberculosis, represents the second world’s deadliest infectious disease, affecting around 9 million people worldwide in 2013. Of those, about 1.1 million died from the disease. The potential of cathelicin, a human AMP, in the treatment of mycobacteriosis and wound regeneration was assessed in pre-clinical trials. (...)

An Investigation into Irish State patronage of the visual arts.

The focus of this research is in ascertaining how and why the Irish state patronises the visual arts. The framework that the state puts in place for the support of the arts influences the creation of art. The initial standpoint from which to evaluate the system is founded on the belief that art is of social good. The second source of belief is in the necessity for an autonomous setting in which it can be created. These two beliefs underpin state patronage of the arts in contemporary society. Therefore they have to be examined carefully in order to see if they hold up. This requires an investigation into the formation of value. This is undertaken by looking into the social development of western society and its influence on the placement of arts value. Establishing how arts value to society is defined provides a means by which to investigate the manner in which the state patronises the visual arts. Two case studies provide the evidence in how the state supports the arts and why it chooses to do so. The Irish Museum of Modem Art is used as an example of the state’s role in the maintenance of the canon of art. The second case study looks at the work being done by Breaking Ground. Breaking Ground is an extensive art project as an element of the regeneration process happening in Ballymun funded by the state. It provides and insight into how the state utilises art in the unification of a social group.

Ireland’s understudied flatfish: reproduction, age and growth of the dab Limanda limanda (L.) in Irish coastal waters

In Ireland, although flatfish form a valuable fishery, little is known about the smallest, the dab Limanda limanda. In this study, a variety of parameters of reproductive development, including ovarian phase description, gonadosomatic index (GSI), hepatosomatic index (HSI), relative condition (Kn) and oocyte size were analysed to provide information on the dab’s reproductive cycle and spawning periods. Sampling were collected monthly over an 18-month period using bottom trawls of the Irish coastline. A six phase macroscopic guide was developed for both sexes of dab, and verified using histology. In comparisons of macroscopic and microscopic phases, there was high agreement in the proposed female guide (86%), with males demonstratively lower (62%). No significant bias was observed between the the two reproductive methods. When the male macroscopic guide was examined, misclassification was high in phase 5 and phase 5 (41%), with 96% of misclassification occurring in adjacent phases. The sampled population was primarily composed of females, with ratios of females to males 1:0.6, although the predominance of females was less noticeable during the reproductive season. Oocyte growth in dab follows asynchronous development, and spawn over a protracted period indicating a batch spawning strategy. Spawning occurred mainly in early spring, with total regeneration of gonads by May. The length at which 50% of the population was reproductively mature was identified as 14cm and 17cm, for male and female dab, respectively. Precision and bias in age determinations using whole otoliths to age dab was investigated using six age readers from various institutions. Low levels of precision were obtained (CV: 10-23%) inferring the need for an alternative methodology. Precision and bias was influence by the level of experience of the reader, with ageing error attributed to interpretative differences and difficulty in edge determination. Sectioned otolith age determinations were subsequently compared to whole otolith age determinations using two age readers experienced in dab ageing. Although increased precision was observed in whole otoliths from previous estimates (CV=0%, 0% APE), sectioned otoliths were used for growth models. This was based on multinominal logistic regression on age length keys developed using both ageing methods. Biological data (length and age) for both sexes was applied to four growth models, where the Akaike criterion and Multi model Inference indicated the logistic model as having the best fit to the collected data. In general, female dab attained a longer length then males, with growth rates significantly different between the two sexes. Length weight relationships between the two sexes were also significantly different.

Studies in general physiology, by Jacques Loeb.

pt. 1

Studies in general physiology, by Jacques Loeb.

pt. 2

III - Contribuição para o estudo biológico e ecológico das Podostemaceae do salto do Piracicaba

1 - The Author, in this 3 thd. contribution, concludes the study of the biology and ecology of the species Tristicha trifaria (Willd.) Spreng. and Mourera aspera (Bong.) Tul., both of the Piracicaba Fall. 2 - According to the results of Dr. Peter van Royen (State Herbarium of Leiden, Holland), who made a complete revision of Podostemaceae of the Piracicaba Fall, the species Tristicha hypnoides (St. Hil.) Spreng. var. Hilarii Tul. and Mnioppsis Glazioviana Warm, correspond, respectively, to theTristicha trifaria (Willd.) Spreng. and Mniopsis weddelliana Tul. Apinagia Accorsii Toledo was transferred by Royen to the genus Wettsteiniola. So, its new name is Wettsteiniola accorsii (Toledo) v. Royen. 3 - Propagation by seeds may occur in the following places: a) placenta of partially open fruits; b) external and internal walls of the open capsules; c) pedicels of the fruits; d) remains of rhizomes, branches, etc. e) organic residues accumulated in water holes in the fall; f) clean rocks, in which the little groups of seedlings seems to be a colony of algae. Seeds adhere to the substrata above by means, of a mucilage produced by the transformation of the external integuments in contact with water. 4 - In the growth of the four species below it was found in Piracicaba Fall conspicuous zoning so scattered: a) Wettsteiniola accorsii (Toledo) v. Royen, in rocks situated just within the water fall, where velocity of the current and aeration of the water are very high. b) Tristicha trifaria (Willd.) Spreng. and Mniopsis weddelliana Tul., in rocks at some distance (100 m more or less) upstream until near the bridge across the river. c) Mourera aspera (Bong.) Tul., 300 m upwards the bridge. 5- During 1949, the ecological conditions of the Piracicaba Fall were changed due to the following factors: a) dry season very long, begining from last period of June until 30 november; b) stopping, during four months, of water from the Atibaia river (one of the components of Piracicaba river) near to the city of Americana, in the place where a new station of the Companhia Paulista de Força e Luz was build. In consequence, most of the Podostemaceae died. On the dry rocks there were only fruits and dried plants. 6 - Tristicha trifaria has the same biological and ecological behavior as the Mniopsis weddelliana,. 7 - The vegetative propagation of Tristicha trifaria is made by increasing of its branches, production of stolons with vegetatives buds and regeneration of old parts in especial conditions of water and aeration. 8 - Mourera aspera has the same vegetative propagation as the Wettsteiniola accorsii; it produces stolons (in very little percentage) with vegetative buds, branches of the rhizomes and regeneration of active old parts. 9 - Frequently, there is, on the plants an accumulation of sand, silt, loam, organic substances, and so on. The quantity of material stored depends of the purity of the water, of the morphology of the plants and of the situation on the fall. 10 - In extrem conditions of dry heat, the surviving of the species in its habitat depends exclusively from germination of seeds in the mentioned substrata. Exceptionally, some plants survive in a few water pockets full with the weak remaining current.

Ophionereis reticulata (Echinodermata, Ophiuroidea)

This study compared the arm regeneration frequencies in two different populations of Ophionereis reticulata (Say, 1825) in São Sebastião, Southeast Brazil and observed arm regeneration between age classes (juvenile and adults) and sexes (male and female). From the 1,170 individuals sampled, 1,089 (92.2%) showed signs of arm regeneration. The relative frequencies of regenerating arms in the two areas were not different (Baleeiro Isthmus: 91.3% and Grande Beach: 99.5%). Both areas also presented similar values for the number of arms regenerating/individual and in the frequency of regenerating individuals. The major part of the regenerating scars was concentrated in the distal portion of the arm. Sub-lethal predation is most likely the cause to the high rates of arm regeneration in O. reticulata. There was no significant differences in the regeneration rates between females (3.57 ± 1.36 arms regenerating/individual) and males (3.47 ± 1.42).

Myeloid Metaplasia of Spleen in Hookworm Disease

We investigated, in the liver and the spleen of ten pures cases of ankylostomiasis haemocytopoietic elements. We verified the weight of spleen in 23 cases of individuals from 3 to 60 years old. In no case did we meet with haemopoietic cells in liver. In seven cases we found in spleen elements of the red series at an advanced evolutional stage (orthochromatic erythroblasts with pyknotic nucleus). In some of these cases we observed megakaryocytes and numerous eosinophilous myelocytes.The three cases which did not show any myeloid metaplasia in spleen were from individuals of over 50 years. Nevertheless, in another case of an individual 59 years old this metaplasia was verified. In individuals of over 20 years, the average weight of spleen in nine cases appeared to be equal to the normal weight. In 14 other cases, between 3 and 14 years of age, the weight of this organ was always sensibly higher than in normal individuals of the corresponding age. These results suggest the possibility of the myeloid metaplasia being the fact responsible for the weight increase of spleen in young individuals victimatized by hookworm anaemia. The remarkable proliferation of orthochromatic erythroblasts shows that the degree and quickness of blood regeneration after iron administration are due, essentially, to the great quantity of haemoglobin previously formed in the spleen and bone marrow of ankylostomized organisms.