AVALIAÇÃO CEFALOMÉTRICA DA ESTABILIDADE DO TRATAMENTO COM O REGULADOR DE FUNÇÃO FRÄNKEL-2

O objetivo desta pesquisa consistiu em comparar as alterações dentárias, esqueléticas e tegumentares promovidas pelo aparelho de Fränkel-2 com um grupo controle, além de observar a estabilidade desses efeitos promovidos pelo tratamento, num período médio de 7,11 anos pós-tratamento. A amostra compreendeu um total de 90 telerradiografias em norma lateral, sendo 54 telerradiografias provenientes de 18 pacientes tratados com o RF-2 avaliados em três fases (T1:início de tratamento;T2: final de tratamento e T3: pós-tratamento) e 36 telerradiografias de 18 pacientes-controle, observados em dois tempos. Para comparação entre os grupos tratado e controle foi utilizado o teste t de Student não pareado. Já para a análise dos valores do grupo tratado nos três tempos (T1, T2 e T3) foi utilizada a Análise de Variância (ANOVA) a um critério e o teste de Tukey (p<0,05). As principais alterações proporcionadas pelo aparelho RF-2 observadas a partir da comparação do grupo tratado com o controle envolveram efeitos mandibulares, principalmente a protrusão e aumento do comprimento mandibular associado com uma rotação horária, que resultou em uma maior altura facial total (N-Me) e ântero-inferior (AFAI), além de suave rotação anti-horária do plano palatino (SN.PP). Os incisivos superiores retruíram e o inferior vestibularizou. Houve uma distalização relativa dos molares superiores juntamente com a diminuição do overjet , desta forma a convexidade do perfil facial tegumentar melhorou. No período pós-tratamento (T3) observou-se uma estabilidade sagital de maxila (SNA) e mandíbula (SNB), das variáveis do padrão facial, da inclinação do incisivo superior, do ângulo nasolabial e do overjet . A mandíbula e a maxila continuaram a crescer no sentido antero-posterior, juntamente com as alturas faciais Houve também a extrusão de incisivos e molares. Já o plano oclusal e o ângulo goníaco diminuíram na fase pós-tratamento.(AU)

AVALIAÇÃO CEFALOMÉTRICA DA ESTABILIDADE DO TRATAMENTO COM O REGULADOR DE FUNÇÃO FRÄNKEL-2

O objetivo desta pesquisa consistiu em comparar as alterações dentárias, esqueléticas e tegumentares promovidas pelo aparelho de Fränkel-2 com um grupo controle, além de observar a estabilidade desses efeitos promovidos pelo tratamento, num período médio de 7,11 anos pós-tratamento. A amostra compreendeu um total de 90 telerradiografias em norma lateral, sendo 54 telerradiografias provenientes de 18 pacientes tratados com o RF-2 avaliados em três fases (T1:início de tratamento;T2: final de tratamento e T3: pós-tratamento) e 36 telerradiografias de 18 pacientes-controle, observados em dois tempos. Para comparação entre os grupos tratado e controle foi utilizado o teste t de Student não pareado. Já para a análise dos valores do grupo tratado nos três tempos (T1, T2 e T3) foi utilizada a Análise de Variância (ANOVA) a um critério e o teste de Tukey (p<0,05). As principais alterações proporcionadas pelo aparelho RF-2 observadas a partir da comparação do grupo tratado com o controle envolveram efeitos mandibulares, principalmente a protrusão e aumento do comprimento mandibular associado com uma rotação horária, que resultou em uma maior altura facial total (N-Me) e ântero-inferior (AFAI), além de suave rotação anti-horária do plano palatino (SN.PP). Os incisivos superiores retruíram e o inferior vestibularizou. Houve uma distalização relativa dos molares superiores juntamente com a diminuição do overjet , desta forma a convexidade do perfil facial tegumentar melhorou. No período pós-tratamento (T3) observou-se uma estabilidade sagital de maxila (SNA) e mandíbula (SNB), das variáveis do padrão facial, da inclinação do incisivo superior, do ângulo nasolabial e do overjet . A mandíbula e a maxila continuaram a crescer no sentido antero-posterior, juntamente com as alturas faciais Houve também a extrusão de incisivos e molares. Já o plano oclusal e o ângulo goníaco diminuíram na fase pós-tratamento.(AU)

In vivo inhibition of rat stellate cell activation by soluble transforming growth factor β type II receptor: A potential new therapy for hepatic fibrosis

Transforming growth factor β (TGF-β) is a well characterized cytokine that appears to play a major role in directing the cellular response to injury, driving fibrogenesis, and, thus, potentially underlying the progression of chronic injury to fibrosis. In this study, we report the use of a novel TGF-β receptor antagonist to block fibrogenesis induced by ligation of the common bile duct in rats. The antagonist consisted of a chimeric IgG containing the extracellular portion of the TGF-β type II receptor. This “soluble receptor” was infused at the time of injury; in some experiments it was given at 4 days after injury, as a test of its ability to reverse fibrogenesis. The latter was assessed by expression of collagen, both as the mRNA in stellate cells isolated from control or injured liver and also by quantitative histochemistry of tissue sections. When the soluble receptor was administered at the time of injury, collagen I mRNA in stellate cells from the injured liver was 26% of that from animals receiving control IgG (P < 0.0002); when soluble receptor was given after injury induction, collagen I expression was 35% of that in control stellate cells (P < 0.0001). By quantitative histochemistry, hepatic fibrosis in treated animals was 55% of that in controls. We conclude that soluble TGF-β receptor is an effective inhibitor of experimental fibrogenesis in vivo and merits clinical evaluation as a novel agent for controlling hepatic fibrosis in chronic liver injury.

An Open-Label Investigation of the Pharmacokinetics and Tolerability of Oral Cysteamine in Adults with Cystic Fibrosis

This study was funded by Health Sciences Scotland (West Medical Building, University Avenue, Glasgow G12 8QQ. UK) and the Cystic Fibrosis Trust (One Aldgate, London. EC3N 1RE. UK). The funders did not contribute to study design, data collection, analysis, this report or the decision to publish.

Protein phosphatase 2C dephosphorylates and inactivates cystic fibrosis transmembrane conductance regulator

cAMP-dependent phosphorylation activates the cystic fibrosis transmembrane conductance regulator (CFTR) in epithelia. However, the protein phosphatase (PP) that dephosphorylates and inactivates CFTR in airway and intestinal epithelia, two major sites of disease, is not certain. We found that in airway and colonic epithelia, neither okadaic acid nor FK506 prevented inactivation of CFTR when cAMP was removed. These results suggested that a phosphatase distinct from PP1, PP2A, and PP2B was responsible. Because PP2C is insensitive to these inhibitors, we tested the hypothesis that it regulates CFTR. We found that PP2Cα is expressed in airway and T84 intestinal epithelia. To test its activity on CFTR, we generated recombinant human PP2Cα and found that it dephosphorylated CFTR and an R domain peptide in vitro. Moreover, in cell-free patches of membrane, addition of PP2Cα inactivated CFTR Cl− channels; reactivation required readdition of kinase. Finally, coexpression of PP2Cα with CFTR in epithelia reduced the Cl− current and increased the rate of channel inactivation. These results suggest that PP2C may be the okadaic acid-insensitive phosphatase that regulates CFTR in human airway and T84 colonic epithelia. It has been suggested that phosphatase inhibitors could be of therapeutic value in cystic fibrosis; our data suggest that PP2C may be an important phosphatase to target.

Cystic fibrosis transmembrane conductance regulator is an epithelial cell receptor for clearance of Pseudomonas aeruginosa from the lung

The cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride ion channel, but its relationship to the primary clinical manifestation of CF, chronic Pseudomonas aeruginosa pulmonary infection, is unclear. We report that CFTR is a cellular receptor for binding, endocytosing, and clearing P. aeruginosa from the normal lung. Murine cells expressing recombinant human wild-type CFTR ingested 30–100 times as many P. aeruginosa as cells lacking CFTR or expressing mutant ΔF508 CFTR protein. Purified CFTR inhibited ingestion of P. aeruginosa by human airway epithelial cells. The first extracellular domain of CFTR specifically bound to P. aeruginosa and a synthetic peptide of this region inhibited P. aeruginosa internalization in vivo, leading to increased bacterial lung burdens. CFTR clears P. aeruginosa from the lung, indicating a direct connection between mutations in CFTR and the clinical consequences of CF.

A functional R domain from cystic fibrosis transmembrane conductance regulator is predominantly unstructured in solution

Phosphorylation of the regulatory (R) domain initiates cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel activity. To discover how the function of this domain is determined by its structure, we produced an R domain protein (R8) that spanned residues 708–831 of CFTR. Phosphorylated, but not unphosphorylated, R8 stimulated activity of CFTR channels lacking this domain, indicating that R8 is functional. Unexpectedly, this functional R8 was predominantly random coil, as revealed by CD and limited proteolysis. The CD spectra of both phosphorylated and nonphosphorylated R8 were similar in aqueous buffer. The folding agent trimethylamine N-oxide induced only a small increase in the helical content of nonphosphorylated R8 and even less change in the helical content of phosphorylated R8. These data, indicating that the R domain is predominantly random coil, may explain the seemingly complex way in which phosphorylation regulates CFTR channel activity.

Global analysis of gene expression in pulmonary fibrosis reveals distinct programs regulating lung inflammation and fibrosis

The molecular mechanisms of pulmonary fibrosis are poorly understood. We have used oligonucleotide arrays to analyze the gene expression programs that underlie pulmonary fibrosis in response to bleomycin, a drug that causes lung inflammation and fibrosis, in two strains of susceptible mice (129 and C57BL/6). We then compared the gene expression patterns in these mice with 129 mice carrying a null mutation in the epithelial-restricted integrin β6 subunit (β6−/−), which develop inflammation but are protected from pulmonary fibrosis. Cluster analysis identified two distinct groups of genes involved in the inflammatory and fibrotic responses. Analysis of gene expression at multiple time points after bleomycin administration revealed sequential induction of subsets of genes that characterize each response. The availability of this comprehensive data set should accelerate the development of more effective strategies for intervention at the various stages in the development of fibrotic diseases of the lungs and other organs.

Blockade of type β transforming growth factor signaling prevents liver fibrosis and dysfunction in the rat

We eliminated type β transforming growth factor (TGF-β) signaling by adenovirus-mediated local expression of a dominant-negative type II TGF-β receptor (AdCATβ-TR) in the liver of rats treated with dimethylnitrosamine, a model of persistent liver fibrosis. In rats that received a single application of AdCATβ-TR via the portal vein, liver fibrosis as assessed by histology and hydroxyproline content was markedly attenuated. All AdCATβ-TR-treated rats remained alive, and their serum levels of hyaluronic acid and transaminases remained at low levels, whereas all the AdCATβ-TR-untreated rats died of liver dysfunction. The results demonstrate that TGF-β does play a central role in liver fibrogenesis and indicate clearly in a persistent fibrosis model that prevention of fibrosis by anti-TGF-β intervention could be therapeutically useful.

Clinical outcome in relation to care in centres specialising in cystic fibrosis: cross sectional study

Objectives: To assess the effect on clinical outcome of managing paediatric and adult patients with cystic fibrosis at specialised cystic fibrosis centres.

A conditional probability analysis of cystic fibrosis transmembrane conductance regulator gating indicates that ATP has multiple effects during the gating cycle

ATP-binding cassette (ABC) transporters bind and hydrolyze ATP. In the cystic fibrosis transmembrane conductance regulator Cl− channel, this interaction with ATP generates a gating cycle between a closed (C) and two open (O1 and O2) conformations. To understand better how ATP controls channel activity, we examined gating transitions from the C to the O1 and O2 states and from these open states to the C conformation. We made three main observations. First, we found that the channel can open into either the O1 or O2 state, that the frequency of transitions to both states was increased by ATP concentration, and that ATP increased the relative proportion of openings into O1 vs. O2. These results indicate that ATP can interact with the closed state to open the channel in at least two ways, which may involve binding to nucleotide-binding domains (NBDs) NBD1 and NBD2. Second, ATP prolonged the burst duration and altered the way in which the channel closed. These data suggest that ATP also interacts with the open channel. Third, the channel showed runs of specific types of open–closed transitions. This finding suggests a mechanism with more than one cycle of gating transitions. These data suggest models to explain how ATP influences conformational transitions in cystic fibrosis transmembrane conductance regulator and perhaps other ABC transporters.

Defective regulatory volume decrease in human cystic fibrosis tracheal cells because of altered regulation of intermediate conductance Ca2+-dependent potassium channels

The cystic fibrosis transmembrane conductance regulator (CFTR) protein has the ability to function as both a chloride channel and a channel regulator. The loss of these functions explains many of the manifestations of the cystic fibrosis disease (CF), including lung and pancreatic failure, meconium ileus, and male infertility. CFTR has previously been implicated in the cell regulatory volume decrease (RVD) response after hypotonic shocks in murine small intestine crypts, an effect associated to the dysfunction of an unknown swelling-activated potassium conductance. In the present study, we investigated the RVD response in human tracheal CF epithelium and the nature of the volume-sensitive potassium channel affected. Neither the human tracheal cell line CFT1, expressing the mutant CFTR-ΔF508 gene, nor the isogenic vector control line CFT1-LC3, engineered to express the βgal gene, showed RVD. On the other hand, the cell line CFT1-LCFSN, engineered to express the wild-type CFTR gene, presented a full RVD. Patch-clamp studies of swelling-activated potassium currents in the three cell lines revealed that all of them possess a potassium current with the biophysical and pharmacological fingerprints of the intermediate conductance Ca2+-dependent potassium channel (IK, also known as KCNN4). However, only CFT1-LCFSN cells showed an increase in IK currents in response to hypotonic challenges. Although the identification of the molecular mechanism relating CFTR to the hIK channel remains to be solved, these data offer new evidence on the complex integration of CFTR in the cells where it is expressed.