Neuropeptides regulate expression of angiogenic growth factors in pulpal fibroblasts

In the dental pulp angiogenesis is crucial for tooth development and a prerequisite for successful repair following injury and inflammation. The role of neuropeptides in pulpal inflammation has been well documented but their role in the regulation of angiogenesis in the dental pulp has not been elucidated. Objectives: The aim was to profile the expression of angiogenic growth factors produced by pulp fibroblasts and to study the effects of neuropeptides on their expression. Methods: Human pulp fibroblasts derived from healthy molar teeth were stimulated with neuropeptides previously identified in dental pulp, namely, Substance P (SP), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP) and calcitonin related gene peptide (CGRP) for 24 and 48 hrs. Simultaneous expression of ten growth factors was quantified using a novel human angiogenesis array (Ray Biotech, USA). Results: Pulp fibroblasts expressed human angiogenic growth factors, VEGF, bFGF, PDGF-BB, HGF, ANG2, HB-EGF, PIGF, angiogenin and leptin. Among the growth factors expressed VEGF, angiogenin and HGF were abundantly expressed compared to others. Neuropeptides induced variable effects on the expression of the angiogenic factors: CGRP potently up-regulated VEGF, bFGF, HGF and PIGF after 24 hr, while NPY tended to down regulate growth factors after 24 hr in culture but markedly up regulated ANG2, bFGF and leptin after 48 hr. SP down regulated expression of all angiogenic growth factors except for leptin, while VIP induced a small increase in expression of each growth factor, irrespective of time. Conclusion: Pulp fibroblasts express a range of angiogenic growth factors including angiogenin and leptin. Neuropeptides regulate the expression of these factors, suggesting an additional role for neuropeptides in the regulation of inflammation and healing in the dental pulp.
This work is supported by TC White Research Fund

Protease activated receptor 2 expression and functionality in caries

Introduction: Protease activated receptors (PARs) are G-protein-coupled transmembrane receptors that are expressed on many cell types and implicated in various inflammatory processes in vivo. The induction of PAR2 as a result of the inflammatory response associated with dental caries remains to be determined. Objectives: The aim was to localise the expression of PAR2 in human dental pulp from carious teeth and to confirm receptor functionality using an in vitro assay. Methods: Dental pulp sections from decalcified carious teeth were examined by immunocytochemsitry. Membrane preparations from cultured pulp fibroblasts were subject to SDS-PAGE and immunoblotting to confirm fibroblast-associated immunoreactivity. The functionality of PAR2 on dental pulp fibroblasts was studied using calcium imaging in the presence of several potential activators including a PAR2 agonist (PAR2-AP), trypsin and pulpal enzymes from a carious tooth. Results: Immunocytochemistry revealed intense PAR2 immunoreactivity on pulpal fibroblasts subjacent to carious lesions but not in surrounding regions of the dental pulp. Pulp specimens from a dental injury model showed no expression of PAR2, suggesting its expression was related to cellular changes associated with ongoing caries. The localisation of PAR2 staining to pulpal fibroblasts in carious teeth was confirmed by Western blotting which revealed PAR2 immunoreactive bands in membrane fractions prepared from pulp fibroblasts. In functional studies, challenge of cultured pupal fibroblasts with PAR2-AP, trypsin and an extract of proteolytic enzymes from a carious dental pulp, showed specific activation of PAR2. Conclusions: This work demonstrates that PAR2 is functional and inducible in human dental pulp fibroblasts in response to caries and that endogenous pulpal enzymes can activate PAR2.

Functional expression of TRPV4 in human periodontal ligament cells

Background: Periodontal ligament (PDL) cells are exposed to physical forces in vivo in response to mastication, parafunction, speech and orthodontic tooth movement. Although it has been shown that PDL cells perceive and respond directly to mechanical stimulation, the nature of the ion channels that mediate this mechanotransduction remain to be fully elucidated. The transient receptor potential (TRP) superfamily of ion channels is believed to play a critical role in sensory physiology, where they act as transducers for thermal, chemical and mechanical stimuli. Recent studies have shown that members of the vanilloid (TRPV) and ankyrin (TRPA) subfamilies encode mechanosensitive TRPs. The vanilloid family member TRPV4 is one such non selective calcium permeable cationic channel which has been shown to be activated by chemical ligands, hypotonicity, and mechanical stimuli. Objectives: The objective of the current study was to investigate functional expression of TRPV4 in cultured human PDL cells. Methods: Human PDL cells were grown in Dulbecco's Modified Eagle Medium with L-glutamine supplemented with 10% fetal bovine serum (FBS), 100UI/ml penicillin and 100μg/ml streptomycin. Cells in passage 4-6 were used in all experiments. TRPV4 functional expression was determined using ratiometric calcium imaging. Cultured cells were loaded with intracellular Ca2+ probe fura-2 and cells were then stimulated with the TRPV4 agonists, 4alpha-phorbol 12,13-didecanoate (4alpha-PDD), GSK1016790A or hypotonic solution. The TRPV4 antagonist RN 1734 was used to block the corresponding agonist responses. Results: PDL fibroblasts responded to application of TRPV4 agonists and hypotonic stimuli by an increase in intracellular calcium which was attenuated in the presence of the TRPV4 antagonist. Conclusions: We have shown for the first time the functional expression of the mechanosensitive TRPV4 channel in human PDL cells. The molecular identity and mechanisms of activation of mechanosensitive TRP channels in PDL cells merit further investigation.

Osteoprotegerin expression by periodontal ligament fibroblasts

Objectives: Receptor Activator of NF-kappaB ligand (RANKL), through binding to its receptor (RANK), plays an important role in osteoclast differentiation and activation. Conversely, osteoprotegerin (OPG), a decoy receptor for RANKL, inhibits osteoclastogenesis and subsequent bone turnover. Little is known about the role of resident periodontal ligament fibroblasts in regulating bone turnover. The aim of this study was to determine (i) if periodontal ligament fibroblasts produced OPG in vitro and (ii) the effects of IL-1b and TGF-b1 on OPG expression. Methods: Three human periodontal ligament fibroblast populations, developed by explant culture, were grown to confluence in 6-well plates in DMEM supplemented with 10% FCS. Cells were washed in HBSS and then cultured for an additional 48 hours in serum-free media supplemented with IL-1b or TGF-b1 at 10ng/ml. OPG expression levels in the conditioned medium were determined by ELISA (R&D Systems, UK) and confirmed by Western blot. Results: All three fibroblast strains produced quantifiable levels of OPG. Both IL-1b and, to a lesser extent, TGF-b1 significantly stimulated OPG expression in all fibroblast strains (p<0.05). Pre-incubation of samples with N-glycosidase F prior to Western blots indicated glycosylation of expressed OPG. Conclusions: These data indicate that periodontal ligament fibroblasts can regulate osteoclast activation via the RANK/RANKL signalling pathway. These fibroblasts may play an important role in regulating bone turnover both in periodontal disease and orthodontic tooth movement.

The Restorability Assessment and Endodontic Access Cavity Interface

Successful root canal treatment requires management of the bacterial infection within the root canal space and protection of residual tooth structure with direct/indirect restorations. Long-term success depends upon prevention of re-infection of the root canal space as well as ensuring favorable distribution of the occlusal forces throughout the residual tooth structure. Appropriate planning and design of the final restoration prior to initiating root canal treatment is paramount in achieving this objective. This article describes simultaneous restorability assessment and access cavity preparation to optimize outcome of both endodontic and prosthodontic treatment of the endodontically involved tooth.

Beneficial effect of a polyphenol-rich diet on cardiovascular risk: a randomised control trial

OBJECTIVES: There is previous epidemiological evidence that intake of polyphenol-rich foods has been associated with reduced cardiovascular disease risk. We aimed to investigate the effect of increasing dietary polyphenol intake on microvascular function in hypertensive participants.

METHODS: All participants completed a 4-week run-in phase, consuming <2 portions of fruit and vegetables (F&V) daily and avoiding berries and dark chocolate. Subjects were then randomised to continue with the low-polyphenol diet for 8 weeks or to consume a high-polyphenol diet of six portions F&V (including one portion of berries/day and 50 g of dark chocolate). Endothelium-dependent (acetylcholine, ACh) and endothelium-independent (sodium nitroprusside) vasodilator responses were assessed by venous occlusion plethysmography. Compliance with the intervention was measured using food diaries and biochemical markers.

RESULTS: Final analysis of the primary endpoint was conducted on 92 participants. Between-group comparison of change in maximum % response to ACh revealed a significant improvement in the high-polyphenol group (p=0.02). There was a significantly larger increase in vitamin C, carotenoids and epicatechin in the high-polyphenol group (between-group difference p<0.001; p<0.001; p=0.008, respectively).

CONCLUSIONS: This study has shown that increasing the polyphenol content of the diet via consumption of F&V, berries and dark chocolate results in a significant improvement in an established marker of cardiovascular risk in hypertensive participants.

Desenvolvimento da linguagem na criança: hábitos orais e perturbações da fala

O tema desta investigação é a análise dos fatores de risco associados às perturbações da linguagem na criança, em particular, o estudo das relações entre hábitos orais, alterações orofaciais e perturbações da fala. Centra-se nas crianças com idades compreendidas entre os 3 e os 9 anos, para identificar o papel de hábitos orais (aleitamento materno, sucção da chupeta, do biberão, do dedo e da língua e onicofagia), tipo de respiração (oral, nasal e misto), alterações orofaciais (oclusão dentária, lábios, língua, palato e freio lingual) nas perturbações da linguagem da criança. A literatura indica que esses hábitos orais, ocorridos de modo prolongado nos primeiros anos de vida da criança, potencializam alterações orofaciais e constituem fatores de risco de determinados tipos de perturbações da fala. A amostra compreende 763 crianças portuguesas com perturbações da linguagem, avaliadas em consulta de terapia da fala, em instituições públicas e privadas, durante os anos de 2008 e 2009; e um grupo de controlo com 100 crianças sem perturbações da fala. A recolha de dados efetuou-se através do preenchimento de uma ficha de registo disponibilizada a cada terapeuta da fala envolvida no estudo. Os dados foram analisados através de estatística descritiva e inferencial. Os principais resultados apontam para a importância dos antecedentes familiares, da respiração oral, das alterações na língua, nos lábios e no palato enquanto fatores preditivos das perturbações da fala das crianças. Quanto à interferência nociva que os hábitos orais poderão ter no desenvolvimento e nas perturbações da linguagem da criança, os resultados não a confirmam. Estes dados contribuem para a intervenção e prevenção terapêuticas mais sustentadas nas perturbações da fala e apontam para a necessidade de maior investimento científico neste domínio.

Calcium, vitamin D, casein and whey protein intakes and periodontitis among Danish adults

Objective: To investigate whether intakes of Ca, vitamin D, casein and whey are associated with periodontitis and to investigate the possibility of interactions between them. Design: Cross-sectional study. An Internet-based, 267-item FFQ was used to assess dietary intake. Intakes of casein (32·0 g/d), whey proteins (9·6 g/d) and vitamin D (5·8 μg/d) were classified as within v. above the 50th percentile. Ca intake was classified as within v. below age-specific recommendations. Severe periodontitis was defined as having ≥2 inter-proximal sites with clinical attachment loss ≥6 mm (not on the same tooth) and ≥1 inter-proximal site with pocket depth ≥5 mm. Since vitamin D influences Ca absorption, models were stratified by lower and higher (<5·8 v. ≥5·8 µg/d) vitamin D intake. Setting Danish Health Examination Survey (DANHES) 2007–2008. Subjects Adult participants (n 3287) in the oral health study of DANHES 2007–2008. Results Intakes of Ca within recommendations (OR=0·76; 95 % CI 0·58, 0·99), whey ≥9·6 g/d (OR=0·75; 95 % CI 0·58, 0·97) and casein ≥32 g/d (OR=0·75 95 % CI 0·58, 0·97) were associated with lower likelihood of severe periodontitis after adjustment for age, gender, education, smoking, sucrose intake, alcohol consumption, number of teeth, daily brushing, regular visits to the dentist and chronic illness, irrespective of vitamin D intake levels. Intake of vitamin D alone was not associated severe with periodontitis. Conclusions Intakes of Ca, casein and whey protein were inversely associated with periodontitis. Consumption of foods rich in Ca, casein and whey (e.g. dairy foods) should be promoted, as they may contribute to the prevention of periodontitis. Further longitudinal studies are required to confirm these associations.

Imaginative Mislocation: Hiroshima’s Genbaku Dome, Ground Zero of the Twentieth Century

The controversy that erupted in March over the publication of Charles Pellegrino’s account of the atomic bombings of Japan, The Last Train from Hiroshima, suggests that the historical legacy of the first military use of atomic weaponry is still fiercely contested in the USA. The spat is merely the latest conflict in a long war over the significance of the bombings, which resurfaces with each new book, exhibition or programme that appears. When the ruins of the Genbaku (Atomic Bomb) Dome – formerly the Hiroshima Prefectural Commercial Exhibition Hall – were nominated as a UNESCO World Heritage Site in 1995, the United States objected on the basis of concerns over a ‘lack of historical perspective’, arguing that the ‘events antecedent to the United States’ use of atomic weapons to end World War II are key to understanding the tragedy of Hiroshima’. The appeal to historical facts by both US diplomats and, more recently, military veterans contrasts with the dehistoricized emphasis of other Western cultural responses to Hiroshima. But what both kinds of reception share is an occlusion of the prehistory of capitalist liberalism, colonialism and imperialism which produces Japanese modernity,a prehistory which is itself built into the Genbaku Dome’s concrete structure, and an afterlife of nuclear pacification which produces the global context of terrorism as the continuation of war by other means.

Calcium, vitamin D, casein and whey protein intakes and periodontitis among Danish adults

OBJECTIVE: To investigate whether intakes of Ca, vitamin D, casein and whey are associated with periodontitis and to investigate the possibility of interactions between them. DESIGN: Cross-sectional study. An Internet-based, 267-item FFQ was used to assess dietary intake. Intakes of casein (32.0 g/d), whey proteins (9.6 g/d) and vitamin D (5.8 mug/d) were classified as within v. above the 50th percentile. Ca intake was classified as within v. below age-specific recommendations. Severe periodontitis was defined as having >/=2 inter-proximal sites with clinical attachment loss >/=6 mm (not on the same tooth) and >/=1 inter-proximal site with pocket depth >/=5 mm. Since vitamin D influences Ca absorption, models were stratified by lower and higher (<5.8 v. >/=5.8 microg/d) vitamin D intake. SETTING: Danish Health Examination Survey (DANHES) 2007-2008. SUBJECTS: Adult participants (n 3287) in the oral health study of DANHES 2007-2008. RESULTS: Intakes of Ca within recommendations (OR=0.76; 95 % CI 0.58, 0.99), whey >/=9.6 g/d (OR=0.75; 95 % CI 0.58, 0.97) and casein >/=32 g/d (OR=0.75 95 % CI 0.58, 0.97) were associated with lower likelihood of severe periodontitis after adjustment for age, gender, education, smoking, sucrose intake, alcohol consumption, number of teeth, daily brushing, regular visits to the dentist and chronic illness, irrespective of vitamin D intake levels. Intake of vitamin D alone was not associated severe with periodontitis. CONCLUSIONS: Intakes of Ca, casein and whey protein were inversely associated with periodontitis. Consumption of foods rich in Ca, casein and whey (e.g. dairy foods) should be promoted, as they may contribute to the prevention of periodontitis. Further longitudinal studies are required to confirm these associations.

Influência da espessura do substrato dental sobre a eficácia clareadora e citotoxicidade de diferentes protocolos de clareamento

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Low-loss austempered ductile iron gears: experimental evaluation comparing materials and lubricants

An experimental study to evaluate the power dissipation of gears was performed. Three low-loss gear models were manufactured using standard 20° pressure angle tools. Austempered ductile iron (ADI) and 20MnCr5 carburized steel gears were tested in an FZG gear test machine using mineral, ester and polyalphaolephine (PAO)-based oils. The results compare power dissipation, the influence of different tooth flank geometries, materials and lubricants. This work concludes that conventional power-transmission gears can be replaced by these improved and more efficient low–loss models, which can be produced using common tools and that steel gears can be successfully replaced by austempered ductile iron gears.

Manobras de condução assistida para veículos submarinos subactuados

A intervenção humana no manuseamento de veículos submarinos operados remotamente (ROVs) é um requisito necessário para garantir o sucesso da missão e a integridade do equipamento. Contudo, a sua teleoperação não é fácil, pelo que a condução assistida destes veículos torna-se relevante. Esta dissertação propõe uma solução para este problema para ROVs de 3DOF (surge, heave e yaw). São propostas duas abordagens distintas – numa primeira propõe-se um sistema de controlo Image Based Visual Servoing (IBVS) tendo em vista a utilização exclusiva de uma câmara (sensor existente neste tipo de sistemas) por forma a melhorar significativamente a teleoperação de um pequeno ROV; na segunda, propõe-se um sistema de controlo cinemático para o plano horizontal do veículo e um algoritmo de uma manobra capaz de dotar o ROV de movimento lateral através de uma trajectória dente-de-serra. Demonstrou-se em cenários de operação real que o sistema proposto na primeira abordagem permite ao operador de um ROV com 3DOF executar tarefas de alguma complexidade (estabilização) apenas através de comandos de alto nível, melhorando assim drasticamente a teleoperação e qualidade de inspecção do veículo em questão. Foi também desenvolvido um simulador do ROV em MATLAB para validação e avaliação das manobras, onde o sistema proposto na segunda abordagem foi validado com sucesso.

Acute Upper Limb Ischemia, a Rare Presentation of Giant Cell Arteritis

Giant cell arteritis (GCA) is a systemic large vessel vasculitis, with extracranial arterial involvement described in 10-15% of cases, usually affecting the aorta and its branches. Patients with GCA are more likely to develop aortic aneurysms, but these are rarely present at the time of the diagnosis. We report the case of an 80-year-old Caucasian woman, who reported proximal muscle pain in the arms with morning stiffness of the shoulders for eight months. In the previous two months, she had developed worsening bilateral arm claudication, severe pain, cold extremities and digital necrosis. She had no palpable radial pulses and no measurable blood pressure. The patient had normochromic anemia, erythrocyte sedimentation rate of 120 mm/h, and a negative infectious and autoimmune workup. Computed tomography angiography revealed concentric wall thickening of the aorta extending to the aortic arch branches, particularly the subclavian and axillary arteries, which were severely stenotic, with areas of bilateral occlusion and an aneurysm of the ascending aorta (47 mm). Despite corticosteroid therapy there was progression to acute critical ischemia. She accordingly underwent surgical revascularization using a bilateral carotid-humeral bypass. After surgery, corticosteroid therapy was maintained and at six-month follow-up she was clinically stable with reduced inflammatory markers. GCA, usually a chronic benign vasculitis, presented exceptionally in this case as acute critical upper limb ischemia, resulting from a massive inflammatory process of the subclavian and axillary arteries, treated with salvage surgical revascularization.

Cortical origin of functional recovery in the somatosensory cortex of the adult mouse after thalamic lesion

Résumé L'accident vasculaire cérébral sensoriel pur est un des syndromes lacunaires, dû à l'occlusion de petits vaisseaux cérébraux, souvent dans le cadre d'une lésion intéressant le noyau ventro-caudal du thalamus. Il produit un hémisyndrome sensitif pur, et parfois un syndrome douloureux se développe à distance de l'événement aigu. Afin d'étudier la récupération fonctionnelle dans le cortex somatosensoriel (SI) après une telle lésion dans le thalamus, un modèle de lésion excitotoxique a été développé dans le système somatosensoriel de la souris adulte, caractérisé par la présence de formations cytoarchitectoniques dans SI appelées "tonneaux". Chacun de ces tonneaux correspond à la représentation corticale d'une vibrisse du museau. L'activité métabolique a été mesurée dans SI à différents intervalles après la lésion, à l'aide de déoxyglucose marqué radioactivement. Dans les deux premiers jours suivant celle-ci, l'activité métabolique diminue de manière importante dans toutes les couches corticales, avec une atteinte plus marquée dans la couche IV, principale projection des axones thalamo-corticaux. Une récupération de l'activité métabolique se produit ensuite, d'autant plus marquée que le délai après la lésion est grand. Cette récupération s'observe dans toutes les couches coticales, les couches I et Vb récupérant plus rapidement que les couches II, III, IV, Va et VI. Cinq semaines après la lésion, l'absence des vibrisses correspondant à la partie déafférentée de SI diminue l'activité métabolique corticale de 32% et démontre l'activation par la périphérie de cette partie de l'écorce, malgré la perte des axones thalamo-corticaux provenant du noyau ventro-caudal. Des expériences de traçage rétrograde ont montré une augmentation des projections intracorticales sur la partie déafférentée de l'écorce, en particulier de longue distance, ainsi que des projections interhémisphériques, mais n'ont pas permis de mettre en évidence de nouvelle projection thalamique, indiquant une origine corticale à la récupération fonctionnelle observée. Abstract To study the degree and time course of the functional recovery in the somatosensory cortex (SI) after an excitotoxic lesion in the adult mouse thalamus, metabolic activity was determined in SI at various times points post lesion. Immediately after the lesion, metabolic activity in the thalamically deafferented part of SI was at its lowest value but increased progressively at subsequent time points. This was seen in all cortical layers, however, layers I and Vb recover more rapidly than layers II, III, IV, Va and VI. Removal of the mystacial whiskers corresponding to the deafferented area, 5 weeks after cortical recovery, produced a subsequent 32% drop in metabolic activity, demonstrating peripheral sensory activation of this part of the cortex. Tracing experiments revealed that the deafferented cortex did not receive a novel thalamic input, but cortico-cortical and contralateral barrel cortex projections to this area were reinforced. We conclude that the cortical functional recovery after a thalamic lesion is, at least partially, due to modified cortico-cortical and callosal projections to the deafferented cortical area.