The large macro- and microscopic variability in kidney morphology among fish makes it difficult to build a “universal” understanding on its function and structure. Species-specific studies are thus needed. Thus, morphological study of brown trout trunk kidney was performed, considering potential seasonal and gender effects.

The melanocortin 5 receptor (MC5R) is a G-protein coupled receptor (GPCR) with a typical seventransmembrane-domain structure. It is assumed that all GPCRs undergo several post-transcriptional modifications during synthesis and folding until finally target to the cell membrane. The available information about the specific domains responsible for the correct targeting of the melanocortin receptors to the cell surface is scarce. Regarding MC5R, it was shown that the first 20 aminoacids of the human receptor can be deleted without affecting the ligand binding affinity, but further deletions of the N terminus resulted in total loss of binding. These results were not directly correlated with the cell surface expression levels of the receptor. Thus, we aim to define the specific MC5R domains important to its correct trafficking and signaling, and preliminary results are here presented.

The 22q11.2 microdeletion is found in most of DiGeorge and velocardiofacial syndromes. These individuals have a wide range of anomalies including congenital heart disease, palatal abnormalities, characteristic facial features, hypocalcaemia, immune deficiency, and learning difficulties. Congenital heart disease, particularly conotruncal malformations are associated with 29% of deletions. This syndrome may be inherited as an autosomal dominant trait, but the majority of patients (93%) have a de novo deletion. To access the presence of the microdeletion in those individuals whose phenotipic changes suggested abnormalities in chromosome 22, a study has been made in several children with congenital heart defects.

Chronic neuropathic pain is a pathology that affects thousands of people worldwide. Antidepressants have been prescribed for the treatment of this sort of pain but the mechanisms underlying their analgesic action remain unknown. Extracellular-signal regulated kinases (ERKs) are being implicated in pain transmission and modulation as well as in the pathophysiology of depression. In order to clarify some of the mechanisms which might be related to the analgesic effect of antidepressants, we started by evaluating possible changes in the pattern of activation of ERKs in rats with chronic constriction injury (CCI), an experimental model of chronic

Several species of the chain-forming marine diatom genus Pseudo-nitzschia produce domoic acid (DA), a neuroexcitant amino acid, responsible for a human amnesic syndrome after consumption of toxified shellfish (ASP). Since 1995, the Portuguese monitoring program has regularly detected the presence of DA in shellfish. So far only P. australis has been implicated, and references therein. Identification of the causative species of Pseudo-nitzchia in natural samples is hampered by difficulties in identification at the light microscope level. Recent studies have shown that ultrastructural details of the wall, observed by transmission electron microscopy, allow the identification of species in good agreement with the phylogenetic and biological species concept.

Frangula azorica V. Grubow (Rhamnaceae), locally known as “sanguinho”, is an Azorean endemism inscribed on the IUCN Red List of Threatened Species. Morphological, chemical and biological studies on F. azorica are scarce, but preliminary studies on the bark of this species enable the identification of anthraquinone derivatives as major compounds of this plant part. This kind of compounds are present and responsible for the laxative activity of Frangulae cortex and Rhamni purshianae cortex, two well known herbal drugs of the Western Pharmacopoeias belonging to the same botanical familly (Rhamnaceae).

Aging is a recognized risk factor for erectile dysfunction (ED) contributing to vascular damage of penile tissue. Vascular system seems to be particularly prone to develop dysfunction along chronological aging, as supported by studies that associate aging with reduced endothelium-dependent dilation, atherosclerosis progression and angiogenic deficit in specific tissues. Cavernous tissue is particularly sensitive to atherosclerotic disease and to structural changes of the small vessels of the penis which conduces to functional impairment.

After a number of replications, human diploid fibroblasts (HDFs) in culture lose the ability to divide, become insensitive to further proliferation and enter a state of replicative senescence (RS). Subcytotoxic doses of several stressful agents such as hydrogen peroxide, tertbutylhydroperoxide or ethanol, are able to cause stress-induced premature senescence (SIPS) in HDFs in vitro. Such senescent cells display many features of RS as growth arrest, senescence associated beta-galactosidase (SA beta-gal), cell enlargement and overexpression of several genes (e.g., p21, TGF beta-1,IGFBP3). During ageing, iron accumulates in several tissues in vivo, and also in senescent HDFs in vitro. Due to its redox-active properties, it promotes hydroxyl radical production (Fenton reaction) and eventually leads to cell injury. Free radical reactions are known to cause the accumulation of intracellular damage resulting in ageing. Iron may thus be able to cause SIPS. The main objective of the present study was to investigate whether the exposure of HDFs to a subcytotoxic concentration of iron is able to cause SIPS.

Highly proliferative cancer cells maintain high rates of glycolysis, producing large amounts of acids, mainly lactic acid. Despite this fact, only the interstitial pH of tumours is low, while the intracellular pH of tumours is either normal or higher than that of normal tissues. Monocarboxylate transporters (MCTs) are transmembrane proteins that, by promoting the efflux of the accumulating acids, constitute one of the most important mechanisms in the maintenance of tumour intracellular pH. MCTs play a central role in cellular metabolism and are essential for the transport of metabolically important monocarboxylates, such as lactate, across the plasma membrane.

Caliciviruses cause rabbit haemorrhagic disease (RHD) that kills more than 90% of the infected adult animals within 1 a 3 days of infection. The virus replicates in the liver and causes a fulminant hepatitis in adult rabbits leading to RHD. A mystery of the calicivirus infection is that young rabbits (less than 8-weeks old) are resistant to the infection, in spite of undergoing viral replication in the liver and of expressing transient hepatitis. Heterophils were the predominant inflammatory cells seen in hepatic tissue of infected adult rabbits, whereas mononuclear cells dominated the inflammatory infiltrates of the infected young rabbits (4-weeks-old). In order to define the role of inflammation in the pathogenesis of the calicivirus infection, we have studied the cellular inflammatory response in young rabbits experimentally infected by calicivirus. For this, we have used transmission electron microscopy (TEM) and flow cytometry to identify the inflammatory cells that infiltrate the hepatic tissue of young rabbits at 48 hours of calicivirus infection. In same infected rabbits, lymphoid organs (spleen and thymus) were used to quantify by flow cytometry the total number of leukocytes seen inside these organs.

Erectile dysfunction (ED) is considered equivalent to endothelial dysfunction and thus an early manifestation of atherosclerosis and cardiovascular disease (CVD). Atherosclerosis that is frequently provoked by regular consumption of high-fat diet (HFD) has been recently recognized as a chronic inflammation condition associated to vessel lipid deposition and vascular smooth cells proliferation that together impair endothelium-dependent relaxation of corpus cavernosum (CC) smooth muscle. It is also well established that HFD regular intake by its own induces endothelial dysfunction. The main objective of this study was to evaluate effects of HFD continuous intake on atherosclerosis progression of CC vessels of the rat. Due to their intervention on atherosclerosisrelated vascular remodelling pathways, angiopoietins (Ang1, Ang2) expression in erectile tissue of this rat experimental model was characterized.

Human fibroblasts cell culture is an important technique for the study of cell biology under various conditions, as exposure to apoptotic stimuli such as UV radiation or hydrogen peroxide administration or chemotherapeutic agent derivatives from staurosporine (STP). STP, isolated from Streptomyces staurospores, is a general inhibitor of protein kinases, and is commonly used to induce apoptosis in a variety of cell in cultures as tumor cell lines, lymphocytes, neurons and osteoblasts. The mechanism by which STP induce cell death is still unkown. Some studies refer that STP induced cell death courses with cytochrome c release, caspase-dependent pathway activation, especially caspase-3, and is inhibited by Bcl-2 overexpression. However cell death still occurs after caspase inhibition by z-VAD-fmk suggesting that caspase independent pathway is also activated.

The earthworm species belonging to the Lumbricidae family (Annelida, Oligochaeta) posses a complex oesophageal organ known as “calciferous gland” which secretes a concentrated suspension of calcium carbonate. Previous studies have demonstrated the non-crystalline structure of this calcareous fluid representing an interesting example of biomineralisation.

The oomycete P. cinnamomi has been described as strong contributing factor to the decline of cork oak and holm oak stands occurring in the Iberian Peninsula. There are no eradication methods available against this pathogen. Molecular mechanisms of oomycete — host interaction are not well understood, but it is known that oomycete species can induce biochemical and physiological processes in their host plants through a diverse array of virulence or avirulence molecules, known as effectors. Several Phytophtora effector molecules, the elicitins, are able to induce cellular defence responses in plants. Among these elicitors the 10- KDa (elicitins) are able to enhance plant defences in a systemic acquired resistance manner, against infection of different pathogens.

Copper, an essential trace element, becomes toxic when its concentration exceeds certain natural levels. Recent in vitro studies demonstrated that copper overload of cells may induce apoptosis through caspase-3 activation. However, the precise mechanism of copper-induced apoptosis in fish is still unclear, even less in O. niloticus where no studies have been reported so far. Accordingly, the main aim of this study was to find if copper induces apoptosis in Oreochromis niloticus gill, through the caspase pathway. Additionally, we intended to evaluate the potential use of activated caspase-3 expression as a waterborne copper biomarker.

Studies demonstrated poor fertilization rates and compromised early embryo development in cases of oocytes with dark and granular ooplasm, or with central granular ooplasm and presence of a refractile body. Many other structural abnormalities of human mature oocytes do exist, but remain to be evaluated. In the present study we characterized granular vacuoles (GVa) of mature metaphase II human oocytes. Surplus abnormal MII oocytes (n=6) with GVa were used under informed consent, after controlled superovulation during IVF treatment cycles. In all cases, patients had normal karyotypes. For electron microscopy oocytes were fixed with karnovsky fixative for 2h at 4°C, post-fixed in 1-2% OsO4 in buffer containing 0,8% K3Fe3+(CN)6, dehydrated in ethanol series, equilibrated with propylene oxide and embedded in Epon. Semithin sections were stained with aqueous azur II and methylene blue (1:1). Ultrathin sections were stained with 3% aquous uranyl acetate (20 min) and Reynols lead citrate (10 min). Sections were observed with a transmission electron microscope JEOL 100CXII operated at 60kV.

Pulicaria is the third largest genus of the tribe Inuleae. It comprises ca. 80 species of shrubs, shrublets and herbs with a European, North African and Asian distribution. All of the 5 European species are represented in the Iberian Peninsula. The genus has taxonomic problems, as recent cladistic analysis showed that, like the other two great genera of Inuleae (Inula and Blumea), Pulicaria is a paraphyletic taxon. In fact, the species investigated so far were placed in two distinct clades. Moreover, the species status of Pulicaria microcephala, a Portuguese endemism of Berlengas Islands, is still controversial. As already demonstrated by several authors, the palynological data are of great importance to understand the evolution, taxonomy and ecology of the Asteraceae. However, in spite of a few relevant contributions, the palynology of Pulicaria is still insufficiently known. In the present work we investigated the palynology of the Iberian species of Pulicaria using light (LM) and scanning electron microscopy (SEM). The exine structure of Pulicaria paludosa was also investigated using transmission electron microscopy (TEM).

Dendritic cells (DC) are major players in initiating immune responses by activating T-lymphocytes. They act as sentinels in peripheral tissues, continuously scavenging for antigens in their immediate surroundings. Their involvement in T-cell responses consists of a linear progression of events starting with capture of antigens in peripheral tissues, such as the skin, followed by migration to draining lymphoid organs and presentation of antigen-derived peptides to induce T-cell priming. In the last years, a number of DC lines have been generated and the electron microscopy has been used to define their characteristics, thus contributing to their formal validation. A cell line with features of early DC precursors was previously established from fetal mouse skin (FSDC), but its ultrastructural organization was not fully investigated. Here we report such investigation using light (LM), scanning electron (SEM) and transmission electron microscopy (TEM). The goal is to use FSDC as a model system to evaluate the safety and effectiveness of selected plant extracts, fractions and isolated polyphenols against inflammatory processes. Our preliminary results with these cells showed anti-inflammatory activity for some of the extracts we are currently investigating.

Lavandula species are aromatic plants that produce and accumulate essential oils in different types of glandular trichomes. The oils protect the aerial parts of the plant against herbivores and pathogens, and are of great economic value for fragrance, pharmaceutical, food and flavour industries. In Portugal there are five spontaneous species of Lavandula which are included in three different sections: Section Lavandula (L. latifolia), Section Pterostoechas (L. multifida) and Section Stoechas (L. luisieri, L. pedunculata, L. viridis). Our preliminary observations showed that these species have a high diversity of trichomes. This, associated with the fact that trichome morphology is often referred as an useful characteristic for systematic purposes, led us to investigate leaf trichome morphology in the five Portuguese species, using scanning electron microscopy (SEM).

Cephalaspideans are a group of opisthobranch gastropods comprising carnivorous and herbivorous species, allowing an investigation of the relationship between these diets and the morphofunctional features of the salivary glands.In this study, the salivary glands of the carnivorous cephalaspidean Philinopsis depicta were observed by light microscopy using semithin sections and by transmission electron microscopy. A central duct runs along the length of these thin ribbon-shaped glands dividing them in two halves, each formed by a single row of tubules perpendicularly attached to the central duct. The simple epithelium of the central duct and lateral tubes contains ciliated cells and two types of secretory cells, named granular cells and cells with apical vacuole (Fig. 1). A very thin outer layer of connective tissue covers the epithelium (Fig. 1). The ciliated cells are numerous but very thin, forming small clusters between secretory cells. The nucleus, several mitochondria and a few lysosomes are located in the apical region were the cells are wider. A very thin cytoplasmic stalk reaches the base of the epithelium and contains bundles of filaments in addition to some mitochondria.