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1.
Osteoporos Int ; 33(10): 2165-2175, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35711006

RESUMO

This post hoc analysis and modeling study examined the mechanism of action of odanacatib using a statistical model to explain sCTx response in ODN-treated patients as a function of other bone-turnover biomarkers that, with other observed biomarker changes, showed that odanacatib persistently inhibited osteoclastic bone removal activity without preventing osteoclastogenesis. INTRODUCTION: Odanacatib (ODN) is an oral selective cathepsin K (CatK) inhibitor, previously in development for osteoporosis treatment. A post hoc analysis examined ODN's mechanism of action on bone-turnover biomarkers. METHODS: A subset of patients who completed 60 months' treatment in the Long-Term Odanacatib Fracture Trial (LOFT; NCT00529373) (N = 112 [57 ODN, 55 placebo]) were evaluated. Serum (s) and urine (u) samples were assayed at baseline and months 6-60 for 10 known bone-remodeling biomarkers: sCTx, uαα- and ußßCTx/Cr, uNTx/Cr, sNTx, uDPD/Cr, sICTP, sTRAP5b, sPINP, and sBSAP. Because the CrossLaps® CTx assay identifies the CTx peptide as well as larger molecular weight CTx-containing peptides, including ICTP, a best-fit model was developed to explain the transient sCTx reduction in ODN-treated patients. RESULTS: ODN persistently reduced the bone-resorption markers sNTx, uNTx/Cr, uαα- and ußßCTx/Cr, and uDPD/Cr, and gradually increased the target-engagement marker sICTP and osteoclast number (sTRAP5b), versus placebo from baseline to month 60. sCTx was transiently reduced with ODN within 12 months, returning to baseline by month 48. Modeling suggested that sCTx changes in the ODN group were primarily due to increased accumulation of larger CTx species, including sICTP. The bone-formation markers sPINP and sBSAP showed partial reductions, versus placebo, in the first 6 months but approached baseline by months 48-60. CONCLUSION: Observed changes in bone-turnover biomarkers support the persistent efficacy of ODN in direct inhibition of osteoclastic bone-resorption activity, without inhibition of osteoclastogenesis. Long-term evaluation also underscores the unique mechanism of ODN on osteoclastic collagen processing and subsequently osteoblastic bone formation. TRIAL REGISTRATION: NCT00529373.


Assuntos
Conservadores da Densidade Óssea , Reabsorção Óssea , Osteoporose Pós-Menopausa , Biomarcadores , Compostos de Bifenilo/uso terapêutico , Conservadores da Densidade Óssea/farmacologia , Conservadores da Densidade Óssea/uso terapêutico , Reabsorção Óssea/induzido quimicamente , Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/prevenção & controle , Catepsina K , Feminino , Humanos , Osteoporose Pós-Menopausa/induzido quimicamente , Osteoporose Pós-Menopausa/tratamento farmacológico , Pós-Menopausa
2.
Immun Ageing ; 18(1): 4, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33441138

RESUMO

Older age is associated with deteriorating health, including escalating risk of diseases such as cancer, and a diminished ability to repair following injury. This rise in age-related diseases/co-morbidities is associated with changes to immune function, including in myeloid cells, and is related to immunosenescence. Immunosenescence reflects age-related changes associated with immune dysfunction and is accompanied by low-grade chronic inflammation or inflammageing. This is characterised by increased levels of circulating pro-inflammatory cytokines such as tumor necrosis factor (TNF), interleukin (IL)-1ß and IL-6. However, in healthy ageing, there is a concomitant age-related escalation in anti-inflammatory cytokines such as transforming growth factor-ß1 (TGF-ß1) and IL-10, which may overcompensate to regulate the pro-inflammatory state. Key inflammatory cells, macrophages, play a role in cancer development and injury repair in young hosts, and we propose that their role in ageing in these scenarios may be more profound. Imbalanced pro- and anti-inflammatory factors during ageing may also have a significant influence on macrophage function and further impact the severity of age-related diseases in which macrophages are known to play a key role. In this brief review we summarise studies describing changes to inflammatory function of macrophages (from various tissues and across sexes) during healthy ageing. We also describe age-related diseases/co-morbidities where macrophages are known to play a key role, focussed on injury repair processes and cancer, plus comment briefly on strategies to correct for these age-related changes.

3.
Ann Chir Plast Esthet ; 64(1): 98-105, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30262251

RESUMO

Clear cell sarcomas (SCC), also called "soft-tissue melanoma", are rare and aggressive tumors that preferentially affect the lower limbs (tendons and fasciae) and which have also been described in head and neck localizations. Their clinical and immunohistochemical mimicry with melanoma makes it difficult to diagnose sarcomas. SCC treatment is mainly focused on large-scale resection surgery with adjuvant radiotherapy because of their low chemo-sensitivity and extreme lymphophilia. In case of head and neck localization, these treatments may lead to function and aesthetic sequelae thus requiring the use of modern techniques of reconstructive surgery. The authors describe the diagnosis, treatment and follow-up of large lingual SCC case using a DIEP free flap reconstruction according to an original technique developed in the department. Given the characteristics of patients with SCC (a high proportion of women between 20 and 40 years old) and its inherent qualities (low morbidity of the donor site, volume delivered and excellent plasticity), the fascio-cutaneous free flap type "DIEP" "taken according to the design of the" Cathedral triptych seems to be a viable choice among the range of reconstruction solutions.


Assuntos
Retalhos de Tecido Biológico , Sarcoma de Células Claras/cirurgia , Neoplasias da Língua/cirurgia , Adulto , Feminino , Glossectomia , Humanos , Reto do Abdome/transplante
4.
J Vis ; 15(13): 14, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26382005

RESUMO

Human memory is content addressable-i.e., contents of the memory can be accessed using partial information about the bound features of a stored item. In this study, we used a cross-feature cuing technique to examine how the human visual system encodes, binds, and retains information about multiple stimulus features within a set of moving objects. We sought to characterize the roles of three different features (position, color, and direction of motion, the latter two of which are processed preferentially within the ventral and dorsal visual streams, respectively) in the construction and maintenance of object representations. We investigated the extent to which these features are bound together across the following processing stages: during stimulus encoding, sensory (iconic) memory, and visual short-term memory. Whereas all features examined here can serve as cues for addressing content, their effectiveness shows asymmetries and varies according to cue-report pairings and the stage of information processing and storage. Position-based indexing theories predict that position should be more effective as a cue compared to other features. While we found a privileged role for position as a cue at the stimulus-encoding stage, position was not the privileged cue at the sensory and visual short-term memory stages. Instead, the pattern that emerged from our findings is one that mirrors the parallel processing streams in the visual system. This stream-specific binding and cuing effectiveness manifests itself in all three stages of information processing examined here. Finally, we find that the Leaky Flask model proposed in our previous study is applicable to all three features.


Assuntos
Percepção de Cores/fisiologia , Sinais (Psicologia) , Memória de Curto Prazo/fisiologia , Percepção de Movimento/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Humanos , Modelos Estatísticos
5.
J Evol Biol ; 27(2): 429-36, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24417506

RESUMO

Hybrid zones may serve as bridges permitting gene flow between species, including alleles influencing the evolution of breeding systems. Using greenhouse crosses, we assessed the likelihood that a hybrid zone could serve as a conduit for transfer of nuclear male-sterility alleles between a gynodioecious species and a hermaphroditic species with very rare females in some populations. Segregation patterns in progeny of crosses between rare females of hermaphroditic Schiedea menziesii and hermaphroditic plants of gynodioecious Schiedea salicaria heterozygous at the male-sterility locus, and between female S. salicaria and hermaphroditic plants from the hybrid zone, were used to determine whether male-sterility was controlled at the same locus in the parental species and the hybrid zone. Segregations of females and hermaphrodites in approximately equal ratios from many of the crosses indicate that the same nuclear male-sterility allele occurs in the parent species and the hybrid zone. These rare male-sterility alleles in S. menziesii may result from gene flow from S. salicaria through the hybrid zone, presumably facilitated by wind pollination in S. salicaria. Alternatively, rare male-sterility alleles might result from a reversal from gynodioecy to hermaphroditism in S. menziesii, or possibly de novo evolution of male sterility. Phylogenetic analysis indicates that some species of Schiedea have probably evolved separate sexes independently, but not in the lineage containing S. salicaria and S. menziesii. High levels of selfing and expression of strong inbreeding depression in S. menziesii, which together should favour females in populations, argue against a reversal from gynodioecy to hermaphroditism in S. menziesii.


Assuntos
Caryophyllaceae/fisiologia , Polinização , Alelos , Fluxo Gênico , Hibridização Genética , Filogenia , Reprodução
6.
Am J Ther ; 21(1): 43-51, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23085762

RESUMO

Hepatic hydrothorax is defined as a pleural effusion in patients with liver cirrhosis in the absence of cardiopulmonary disease. The estimated prevalence among patients with liver cirrhosis is approximately 5-6%. The pathophysiology involves the passage of ascitic fluid from the peritoneal cavity to the pleural space through diaphragmatic defects. The diagnosis is made from clinical presentation and confirmed by diagnostic thoracentesis with pleural fluid analysis. The initial medical management is sodium restriction and diuretics, but liver transplantation provides the only definitive therapy. For patients who are not transplant candidates and those who await organ availability, other therapeutic modalities that are to be considered include transjugular intrahepatic portosystemic shunt placement, videoassisted thoracoscopic surgery repair, pleurodesis, and vasoconstrictors (eg, octreotide and terlipressin). The primary therapeutic goals are to reduce ascitic fluid production and improve symptoms to bridge the time for liver transplantation.


Assuntos
Doença Hepática Terminal/tratamento farmacológico , Doença Hepática Terminal/terapia , Hidrotórax/tratamento farmacológico , Hidrotórax/terapia , Doença Hepática Terminal/complicações , Doença Hepática Terminal/diagnóstico , Doença Hepática Terminal/fisiopatologia , Doença Hepática Terminal/cirurgia , Humanos , Hidrotórax/complicações , Hidrotórax/diagnóstico , Hidrotórax/fisiopatologia , Hidrotórax/cirurgia , Transplante de Fígado , Pleurodese , Derivação Portossistêmica Transjugular Intra-Hepática
7.
Phys Rev Lett ; 106(13): 131302, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21517371

RESUMO

We report results from a reanalysis of data from the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory. Data taken between October 2006 and September 2008 using eight germanium detectors are reanalyzed with a lowered, 2 keV recoil-energy threshold, to give increased sensitivity to interactions from weakly interacting massive particles (WIMPs) with masses below ∼10 GeV/c(2). This analysis provides stronger constraints than previous CDMS II results for WIMP masses below 9 GeV/c(2) and excludes parameter space associated with possible low-mass WIMP signals from the DAMA/LIBRA and CoGeNT experiments.

8.
Mucosal Immunol ; 13(1): 110-117, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31636346

RESUMO

Eosinophilic esophagitis (EoE) is a chronic Th2 antigen-driven disorder associated with tissue remodeling. Inflammation and remodeling lead to esophageal rigidity, strictures, and dysphagia. TGFß1 drives esophageal remodeling including epithelial barrier dysfunction and subepithelial fibrosis. A functional SNP in the TGFß1 gene that increases its transcription (C-509T) is associated with elevated numbers of esophageal TGFß1-expressing cells. We utilized esophageal biopsies and fibroblasts from TT-genotype EoE children to understand if TGFß1 influenced fibroblast and epithelial cell function in vivo. Genotype TT EoE esophageal fibroblasts had higher baseline TGFß1, collagen1α1, periostin, and MMP2 (p < 0.05) gene expression and distinct contractile properties compared with CC genotype (n = 6 subjects per genotype). In vitro TGFß1 exposure caused greater induction of target gene expression in genotype CC fibroblasts (p < 0.05). Esophageal biopsies from TT-genotype subjects had significantly less epithelial membrane-bound E-cadherin (p < 0.01) and wider cluster distribution at nanometer resolution. TGFß1 treatment of stratified primary human esophageal epithelial cells and spheroids disrupted transepithelial resistance (p < 0.001) and E-cadherin localization (p < 0.0001). A TGFß1-receptor-I inhibitor improved TGFß1-mediated E-cadherin mislocalization. These data suggest that EoE severity can depend on genotypic differences that increase in vivo exposure to TGFß1. TGFß1 inhibition may be a useful therapy in subsets of EoE patients.


Assuntos
Esofagite Eosinofílica/genética , Células Epiteliais/fisiologia , Fibroblastos/fisiologia , Genótipo , Mucosa Intestinal/imunologia , Fator de Crescimento Transformador beta1/genética , Adesão Celular , Células Cultivadas , Criança , Esofagite Eosinofílica/imunologia , Feminino , Fibrose , Estudos de Associação Genética , Humanos , Mucosa Intestinal/patologia , Masculino , Polimorfismo de Nucleotídeo Único
9.
Phys Rev Lett ; 103(14): 141802, 2009 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-19905561

RESUMO

We report on the first axion search results from the Cryogenic Dark Matter Search (CDMS) experiment at the Soudan Underground Laboratory. An energy threshold of 2 keV for electron-recoil events allows a search for possible solar axion conversion into photons or local galactic axion conversion into electrons in the germanium crystal detectors. The solar axion search sets an upper limit on the Primakov coupling g(agammagamma) of 2.4x10(-9) GeV-1 at the 95% confidence level for an axion mass less than 0.1 keV/c2. This limit benefits from the first precise measurement of the absolute crystal plane orientations in this type of experiment. The galactic axion search analysis sets a world-leading experimental upper limit on the axioelectric coupling g(aee) of 1.4x10(-12) at the 90% confidence level for an axion mass of 2.5 keV/c2.

10.
J Biomech ; 81: 68-75, 2018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30274737

RESUMO

Stent size selection and placement are among the most challenging tasks in the treatment of pulmonary artery stenosis in congenital heart defects (CHD). Patient-specific 3D model from CT or MR improves the understanding of the patient's anatomy and information about the hemodynamics aid in patient risk assessment and treatment planning. This work presents a new approach for personalized stent design in pulmonary artery interventions combining personalized patient geometry and hemodynamic simulations. First, the stent position is initialized using a geometric approach. Second, the stent and artery expansion, including the foreshortening behavior of the stent is simulated. Two stent designs are considered, a regular stent and a Y-stent for bifurcations. Computational fluid dynamics (CFD) simulations of the blood flow in the initial and expanded artery models are performed using patient-specific boundary conditions in form of a pulsatile inflow waveform, 3-element Windkessel outflow conditions, and deformable vessel walls. The simulations have been applied to 16 patient cases with a large variability of anatomies. Finally, the simulations have been clinically validated using retrospective imaging from angiography and pressure measurements. The simulated pressure, volume flow and flow velocity values were on the same order of magnitude as the reference values obtained from clinical measurements, and the simulated stent placement showed a positive impact on the hemodynamic values. Simulation of geometric changes combined with CFD simulations offers the possibility to optimize stent type, size, and position by evaluating different configurations before the intervention, and eventually allow to test customized stent geometries and new deployment techniques in CHD.


Assuntos
Cardiopatias Congênitas/fisiopatologia , Modelos Cardiovasculares , Modelagem Computacional Específica para o Paciente , Fluxo Pulsátil , Stents , Adolescente , Angiografia , Artérias/diagnóstico por imagem , Artérias/fisiopatologia , Criança , Pré-Escolar , Simulação por Computador , Desenho de Equipamento , Feminino , Cardiopatias Congênitas/diagnóstico por imagem , Humanos , Hidrodinâmica , Lactente , Masculino
11.
J Clin Invest ; 102(5): 881-92, 1998 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-9727056

RESUMO

Osteoclast activation is initiated by adhesion to the bone surface, followed by cytoskeletal rearrangement, the formation of the sealing zone, and a polarized ruffled membrane. This study shows that PYK2/CAKbeta/RAFTK, a cytoplasmic kinase related to the focal adhesion kinase, is highly expressed in rat osteoclasts in vivo. Using murine osteoclast-like cells (OCLs) or their mononuclear precursors (pOCs), generated in a coculture of bone marrow and osteoblastic MB1.8 cells, we show: (a) tyrosine phosphorylation of PYK2 upon ligation of beta3 integrins or adhesion of pOCs to serum, vitronectin, osteopontin, or fibronectin but not to laminin or collagen; (b) coimmunoprecipitation of PYK2 and c-Src from OCLs; (c) PYK2 binding to the SH2 domains of Src; (d) marked reduction in tyrosine phosphorylation and kinase activity of PYK2 in OCLs derived from Src (-/-) mice, which do not form actin rings and do not resorb bone; (e) PYK2 phosphorylation by exogeneous c-Src; (f) translocation of PYK2 to the Triton X-100 insoluble cytoskeletal fraction upon adhesion; (g) localization of PYK2 in podosomes and the ring-like structures in OCLs plated on glass and in the sealing zone in OCLs plated on bone; and (h) activation of PYK2, in the presence of MB1.8 cells, parallels the formation of sealing zones and pit resorption in vitro and is reduced by echistatin or calcitonin and cytochalasin D. Taken together, these findings suggest that Src-dependent tyrosine phosphorylation of PYK2 is involved in the adhesion-induced formation of the sealing zone, required for osteoclastic bone resorption.


Assuntos
Adesão Celular/fisiologia , Osteoclastos/enzimologia , Proteínas Tirosina Quinases/fisiologia , Receptores de Vitronectina/metabolismo , Quinases da Família src/metabolismo , Animais , Células da Medula Óssea/metabolismo , Reabsorção Óssea/metabolismo , Moléculas de Adesão Celular/fisiologia , Linhagem Celular , Colecalciferol/farmacologia , Técnicas de Cocultura , Ativação Enzimática/fisiologia , Proteínas da Matriz Extracelular/metabolismo , Quinase 1 de Adesão Focal , Quinase 2 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Regulação da Expressão Gênica/genética , Imuno-Histoquímica , Camundongos , Fosforilação , RNA Mensageiro/metabolismo , Tirosina/metabolismo , Domínios de Homologia de src/fisiologia
12.
Neuro Endocrinol Lett ; 28 Suppl 4: 18-9, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18030252

RESUMO

Etiology, risk factors, treatment and outcome of 21 cases of bacterial meningitis diagnosed in excessive alcohol consumers within 5 years of national community acquired meningitis survey in Slovakia is reported.


Assuntos
Alcoolismo/complicações , Alcoolismo/epidemiologia , Meningites Bacterianas/complicações , Meningites Bacterianas/epidemiologia , Adulto , Infecções Comunitárias Adquiridas/epidemiologia , Inquéritos Epidemiológicos , Humanos , Masculino , Meningite Pneumocócica/complicações , Meningite Pneumocócica/epidemiologia , Fatores de Risco , Eslováquia/epidemiologia , Resultado do Tratamento
14.
Neuro Endocrinol Lett ; 28 Suppl 3: 25-6, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18030272

RESUMO

Meningitis associated with bacteremia is rare. Bacteremic form of meningitis occurred in 28 of 201 cases of community acquired meningitis (14%) in Slovakia within last 17 years. Bacteremic meningitis was associated with diabetes (21.4% vs. 7.5%, p=0.02) and with higher treatment failures (32.1% vs. 9.5%, p=0.01) and higher mortality (25% vs. 12.4%, NS). In univariate analysis comparing 28 cases of bacteremic community acquired bacterial meningitis (BCBM) to all CBM, no significant risk factor concerning underlying disease (cancer, ENT infection, alcohol abuses, trauma, splenectomy, etc.) or etiology was observed apart of diabetes mellitus, which was more common among bacteremic meningitis (21.4% vs. 7.5%, p=0.02). Mortality (25% vs. 12.4%, NS) insignificantly but therapy failure (32.1% vs. 9.5%, p=0.01) was significantly more frequently observed among meningitis with bacteremia. N. meningitis was the commonest causative agent (8 of 28 cases) followed by Str. pneumoniae (6), gram-negative bacteria (6), S. aureus (4) and H. influenzae (2).


Assuntos
Bacteriemia/complicações , Complicações do Diabetes/microbiologia , Meningites Bacterianas/complicações , Bacteriemia/terapia , Bactérias/isolamento & purificação , Infecções Comunitárias Adquiridas/complicações , Infecções Comunitárias Adquiridas/microbiologia , Infecções Comunitárias Adquiridas/terapia , Complicações do Diabetes/terapia , Diabetes Mellitus/microbiologia , Humanos , Meningites Bacterianas/microbiologia , Meningites Bacterianas/terapia , Avaliação de Resultados em Cuidados de Saúde , Fatores de Risco , Falha de Tratamento
15.
Appl Spectrosc ; 60(11): 1293-6, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17132447

RESUMO

A Ni-Co-As ore sample from Cobalt City, Ontario, Canada, was examined with scanning electron microscopy and energy dispersive X-ray analysis. In addition to cobaltian pararammelsbergite with variable cobalt content, for which Cobalt City is the type locality, and erythrite, one new mineral was observed for this locality. Well-formed crystals of arsenolite, As(2)O(3), were found embedded in what appears to be fibrous spherocobaltite, CoCO(3). Additional information was obtained by Raman microscopy, confirming the identification of the arsenolite. Both are considered to be secondary minerals formed by exposure to air resulting in oxidation and the formation of secondary carbonates.

16.
Bone ; 88: 113-124, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27126999

RESUMO

The objectives here were to evaluate the effects of odanacatib (ODN) at doses exceeding the clinical exposure on biomechanical properties of lumbar vertebrae (LV), hip and central femur (CF), and compare ODN to alendronate (ALN) on bone remodeling/modeling in ovariectomized (OVX) monkeys. Ten days post-surgery, animals were treated with vehicle (VEH), ODN-L (2mg/kg/day, p.o.), ODN-H (8/4mg/kg/day), or ALN (30µg/kg/week, s.c.) for 20months. An intact group was also included. ODN-L provided systemic exposures of 1.8-fold of clinical exposure. ODN-H started at 20-fold for 5.5months, and then reduced to 7.8-fold of clinical exposure, compared to ALN at approximated clinical exposure. From cross sectional analyses, LV density and peak load in ODN at both doses or ALN were not different from VEH or Intact. However, cortical thickness of femoral neck (FN) and CF in ODN were higher (21-34%, p<0.05) than VEH, due to smaller endocortical (Ec) perimeter of FN (10-11%; p<0.05) and CF (9-12%; ODN-L, p<0.05), and larger CF periosteal (Ps) perimeter (2-12%; ODN-H, p<0.001) versus VEH. ODN groups also showed slightly higher cortical porosity and Ps non-lamellar bone in CF. ODN-H treatment resulted in higher CF peak load (p<0.05) versus VEH. For all bone sites analyzed, a positive, linear relationship (r(2)=0.46-0.69, p<0.0001) of peak load to density or structural parameters was demonstrated. No treatment-related differences in the derived intrinsic strength properties were evidenced as compared between groups. ALN reduced all remodeling surfaces without affecting Ps modeling. Trabecular and intracortical remodeling were reduced in ODN groups, similar to ALN. Ec mineralizing surface in ODN-H trended to be lower than VEH by month 20, but Ec bone formation indices in ODN groups generally were not different from VEH. Ps modeling in ODN groups was significantly higher than other treatment groups. This study overall demonstrated the bone safety profile of ODN and its unique mechanism on cortical bone supporting the clinical application for osteoporosis treatment.


Assuntos
Compostos de Bifenilo/farmacologia , Remodelação Óssea/efeitos dos fármacos , Osso e Ossos/anatomia & histologia , Osso e Ossos/fisiologia , Ovariectomia , Absorciometria de Fóton , Alendronato/farmacologia , Animais , Fenômenos Biomecânicos , Densidade Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Osso Esponjoso/anatomia & histologia , Osso Esponjoso/efeitos dos fármacos , Osso Esponjoso/fisiologia , Osso Cortical/anatomia & histologia , Osso Cortical/efeitos dos fármacos , Osso Cortical/fisiologia , Densitometria , Relação Dose-Resposta a Droga , Feminino , Macaca mulatta , Tamanho do Órgão/efeitos dos fármacos , Análise de Regressão , Tomografia Computadorizada por Raios X
17.
Mol Endocrinol ; 2(5): 452-8, 1988 May.
Artigo em Inglês | MEDLINE | ID: mdl-3419434

RESUMO

The chemically synthesized signal peptide (native-sequence signal peptide) of preproparathyroid hormone exhibits signal sequence-like activity by inhibiting the translocation/processing of precursor proteins to their mature forms in an in vitro translation system. In order to prepare a biologically functional radiolabeled form of this peptide, we undertook structure-function studies of the native-sequence signal peptide. Since conventional iodination of peptides is performed under oxidizing conditions, chemical design efforts were focused on the oxidation-labile residues, methionine and cysteine, present in the native sequence. Substitution of the three methionines with norleucine and the single cysteine with alanine yielded a surfur-free analog, [Nle-(-25), Nle-(-21),Nle-(-18),Ala-(-14),D-Tyr-(+1)]pre-proPTH-(-29-+1)amide, which is resistant to oxidation and active in the inhibition of processing assay. An interaction between the signal region and one of the components of the intracellular secretory apparatus, signal recognition particle (SRP), was demonstrated: iodinated sulfur-free analog was cross-linked (using the homo-bifunctional reagent disuccinimidyl suberate) to the 54 kilodalton (kDa) subunit of SRP. The 68 kDa and 72 kDa subunits of SRP were also labeled, but to a lesser extent, by the iodinated peptide.


Assuntos
Hormônio Paratireóideo/síntese química , Precursores de Proteínas/síntese química , Sinais Direcionadores de Proteínas/síntese química , Sequência de Aminoácidos , Reagentes de Ligações Cruzadas , Eletroforese em Gel de Poliacrilamida , Humanos , Iodo/farmacologia , Radioisótopos do Iodo , Marcação por Isótopo , Dados de Sequência Molecular , Hormônio Paratireóideo/farmacologia , Precursores de Proteínas/farmacologia , Sinais Direcionadores de Proteínas/farmacologia , Relação Estrutura-Atividade , Enxofre/farmacologia
18.
Anticancer Res ; 35(5): 2487-92, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25964521

RESUMO

Chest radiotherapy continues to play an important role in the treatment of breast cancer, Hodgkin's lymphoma, and other malignancies. Subsequent cardiac injury has been described involving essentially all structures of the heart, with most radiation-induced injury being progressive in nature. Our understanding over the multifactorial etiology and development of radiation-associated cardiac injury has advanced, leading to improved techniques aimed at decreasing cardiac radiation exposure and associated risks. Monitoring after radiotherapy clearly appears to be indicated; however, optimal recommendations regarding cardiac screening remain difficult to establish.


Assuntos
Doenças Cardiovasculares/patologia , Traumatismos Cardíacos/patologia , Lesões por Radiação/patologia , Radioterapia/efeitos adversos , Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Feminino , Doença de Hodgkin/patologia , Doença de Hodgkin/radioterapia , Humanos , Fatores de Risco
19.
Endocrinology ; 139(3): 1401-10, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9492077

RESUMO

Echistatin, an RGD-containing peptide, was shown to inhibit the acute calcemic response to exogenous PTH or PTH-related protein (PTH-rP) in thyroparathyroidectomized rats, suggesting that echistatin inhibits bone resorption. In this study: 1) we present histological evidence for echistatin inhibition of bone resorption in mice with secondary hyperparathyroidism, and show that 2) echistatin binds to osteoclasts in vivo, 3) increases osteoclast number, and 4) does not detectably alter osteoclast morphology. Infusion of echistatin (30 microg/kg x min) for 3 days prevented the 2.6-fold increase in tibial cancellous bone turnover and the 36% loss in bone volume, produced by a low calcium diet. At the light microscopy level, echistatin immunolocalized to osteoclasts and megakaryocytes. Echistatin treatment increased osteoclast-covered bone surface by about 50%. At the ultrastructural level, these osteoclasts appeared normal, and the fraction of cells containing ruffled borders and clear zones was similar to controls. Echistatin was found on the basolateral membrane and in intracellular vesicles of actively resorbing osteoclasts. Weak labeling was found in the ruffled border, and no immunoreactivity was detected at the clear zone/bone surface interface. These findings provide histological evidence for echistatin binding to osteoclasts and for inhibition of bone resorption in vivo, through reduced osteoclast efficacy, without apparent changes in osteoclast morphology.


Assuntos
Reabsorção Óssea/prevenção & controle , Hiperparatireoidismo Secundário/patologia , Peptídeos/farmacologia , Receptores de Vitronectina/antagonistas & inibidores , Animais , Peptídeos e Proteínas de Sinalização Intercelular , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Osteoclastos/efeitos dos fármacos , Osteoclastos/ultraestrutura , Hormônio Paratireóideo/farmacologia , Peptídeos/metabolismo
20.
Endocrinology ; 139(12): 5182-93, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9832459

RESUMO

The vitronectin receptor alpha(v)beta3 is highly expressed in osteoclasts and was shown to play a critical role in osteoclast function in vivo. The objective of this study was to examine the role of alpha(v)beta3 integrin in osteoclast formation in vitro using the inhibitory disintegrin echistatin, an RGD-containing snake venom. We documented by immunocytochemistry and Northern blot analysis that during murine osteoclast-like cell (OCL) formation in a coculture of mouse osteoblastic MB1.8 cells and bone marrow cells there is increased expression of the alpha(v) and beta3 integrin subunits. Echistatin binds preferentially to the membrane fraction of isolated enriched OCLs (IC50 = 0.6 nM), and this binding is inhibited by vitronectin receptor-blocking polyclonal antibodies. Additionally, cross-linking of radiolabeled echistatin to OCLs, followed by immunoprecipitation with antibodies to vitronectin or fibronectin receptors, shows that alpha(v)beta3 integrin is the predominant receptor for echistatin in this system. In this coculture, echistatin completely inhibits the formation of multinucleated OCLs, but not that of mononuclear prefusion OCLs (pOCs). This inhibition is RGD and dose dependent (IC50 = 0.7 nM). We tested the hypothesis that inhibition of OCL formation may be due to interference with pOC migration and found that echistatin inhibited macrophage colony-stimulating factor-induced migration and fusion of pOCs (IC50 = 1 and 0.6 nM, respectively). Echistatin inhibition of pOCs migration and fusion is also RGD dependent. These results suggest that the integrin alpha(v)beta3 plays a role in pOC migration, which can explain the inhibitory effect of echistatin on multinucleated osteoclast formation in vitro.


Assuntos
Proteínas de Bactérias , Núcleo Celular/ultraestrutura , Osteoclastos/efeitos dos fármacos , Peptídeos/farmacologia , Animais , Células da Medula Óssea/fisiologia , Calcitriol/farmacologia , Contagem de Células , Fusão Celular , Movimento Celular/efeitos dos fármacos , Técnicas de Cocultura , Peptídeos e Proteínas de Sinalização Intercelular , Camundongos , Camundongos Endogâmicos BALB C , Osteoclastos/citologia , Osteoclastos/fisiologia , Osteoclastos/ultraestrutura , Peptídeos/metabolismo , Proteínas de Ligação a RNA/metabolismo , Receptores de Vitronectina/metabolismo , Receptores de Vitronectina/fisiologia , Fatores de Transcrição/metabolismo
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