RESUMO
BACKGROUND: Our understanding of the etiology, pathophysiology, phenotypic diversity, and progression of Parkinson's disease has stagnated. Consequently, patients do not receive the best care, leading to unnecessary disability, and to mounting costs for society. The Personalized Parkinson Project (PPP) proposes an unbiased approach to biomarker development with multiple biomarkers measured longitudinally. Our main aims are: (a) to perform a set of hypothesis-driven analyses on the comprehensive dataset, correlating established and novel biomarkers to the rate of disease progression and to treatment response; and (b) to create a widely accessible dataset for discovery of novel biomarkers and new targets for therapeutic interventions in Parkinson's disease. METHODS/DESIGN: This is a prospective, longitudinal, single-center cohort study. The cohort will comprise 650 persons with Parkinson's disease. The inclusion criteria are purposely broad: age ≥ 18 years; and disease duration ≤5 years. Participants are followed for 2 years, with three annual assessments at the study center. Outcomes include a clinical assessment (including motor and neuro-psychological tests), collection of biospecimens (stool, whole blood, and cerebrospinal fluid), magnetic resonance imaging (both structural and functional), and ECG recordings (both 12-lead and Holter). Additionally, collection of physiological and environmental data in daily life over 2 years will be enabled through the Verily Study Watch. All data are stored with polymorphic encryptions and pseudonyms, to guarantee the participants' privacy on the one hand, and to enable data sharing on the other. The data and biospecimens will become available for scientists to address Parkinson's disease-related research questions. DISCUSSION: The PPP has several distinguishing elements: all assessments are done in a single center; inclusion of "real life" subjects; deep and repeated multi-dimensional phenotyping; and continuous monitoring with a wearable device for 2 years. Also, the PPP is powered by privacy and security by design, allowing for data sharing with scientists worldwide respecting participants' privacy. The data are expected to open the way for important new insights, including identification of biomarkers to predict differences in prognosis and treatment response between patients. Our long-term aim is to improve existing treatments, develop new therapeutic approaches, and offer Parkinson's disease patients a more personalized disease management approach. TRIAL REGISTRATION: Clinical Trials NCT03364894 . Registered December 6, 2017 (retrospectively registered).
Assuntos
Biomarcadores , Doença de Parkinson , Pessoas com Deficiência , Progressão da Doença , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Medicina de Precisão/métodos , Estudos Prospectivos , Projetos de PesquisaRESUMO
Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by increased peripheral immune platelet destruction and megakaryocyte defects in the bone marrow. Although ITP was originally thought to be primarily due to antibody-mediated autoimmunity, it is now clear that T cells also play a significant role in the disease. However, the exact interplay between platelet destruction, megakaryocyte dysfunction and the elements of both humoral and cell-mediated immunity in ITP remains incompletely defined. While most studies have focused on immune platelet destruction in the spleen, an additional possibility is that the antiplatelet antibodies can also destroy bone marrow megakaryocytes. To address this, we negated the effects of T cells by utilizing an in vivo passive ITP model where BALB/c mice were administered various anti-αIIb, anti-ß3 or anti-GPIb antibodies or antisera and platelet counts and bone marrow megakaryocytes were enumerated. Our results show that after 24 hours, all the different antiplatelet antibodies/sera induced variable degrees of thrombocytopenia in recipient mice. Compared with naïve control mice, however, histological examination of the bone marrow revealed that only 2 antibody preparations (mouse-anti-mouse ß3 sera and an anti- αIIb monoclonal antibody (MWReg30) could affect bone marrow megakaryocyte counts. Our study shows that while most antiplatelet antibodies induce acute thrombocytopenia, the majority of them do not affect the number of megakaryocytes in the bone marrow. This suggests that other mechanisms may be responsible for megakaryocyte abnormalities seen during immune thrombocytopenia.
Assuntos
Autoanticorpos/imunologia , Plaquetas/imunologia , Megacariócitos/patologia , Púrpura Trombocitopênica Idiopática/imunologia , Púrpura Trombocitopênica Idiopática/patologia , Animais , Células da Medula Óssea/patologia , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Although most children with Hirschsprung disease ultimately do well, many experience a variety of ongoing problems after pull-through surgery. The most common include obstructive symptoms, soiling, enterocolitis and failure to thrive. The purpose of this guideline is to present a rational approach to the management of postoperative obstructive symptoms in children with Hirschsprung disease. The American Pediatric Surgical Association Board of Governors established a Hirschsprung Disease Interest Group. Group discussions, literature review and expert consensus were then used to summarize the current state of knowledge regarding causes, methods of diagnosis, and treatment approaches to children with obstructive symptoms following pull-through for Hirschsprung disease. Causes of obstructive symptoms post-pull-through include mechanical obstruction; persistent or acquired aganglionosis, hypoganglionosis, or transition zone pull-through; internal sphincter achalasia; disordered motility in the proximal intestine that contains ganglion cells; or functional megacolon caused by stool-holding behavior. An algorithm for the diagnosis and management of obstructive symptoms after a pull-through for Hirschsprung disease is presented. A stepwise, logical approach to the diagnosis and management of patients experiencing obstructive symptoms following pull-through for Hirschsprung disease can facilitate treatment. Level of evidence V.
Assuntos
Doença de Hirschsprung/cirurgia , Obstrução Intestinal/diagnóstico , Obstrução Intestinal/terapia , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/terapia , Toxinas Botulínicas/uso terapêutico , Criança , Pré-Escolar , Enema , Feminino , Doença de Hirschsprung/complicações , Humanos , Lactente , Obstrução Intestinal/etiologia , Masculino , Guias de Prática Clínica como AssuntoRESUMO
AIMS: A prospective meta-analysis of phase 3 trials showed lower rates of nocturnal hypoglycaemia with insulin degludec vs. insulin glargine. We investigated the consistency of the results across different definitions of hypoglycaemia. METHODS: This post-hoc, patient-level meta-analysis included six randomized, controlled, 26- or 52-week phase 3a trials in insulin-naïve participants with Type 2 diabetes mellitus (Type 2 diabetesinsulin naïve ), participants with Type 2 diabetes mellitus using basal-bolus therapy (Type 2 diabetesBB ) and those with Type 1 diabetes mellitus. We used three definitions of hypoglycaemia and different timescales for the nocturnal period. Rates were analysed for the entire core trial period, the 'maintenance period' only, and the extension trial set population. Analyses utilized a negative binomial regression model. RESULTS: In Type 2 diabetesinsulin naïve participants, risk of nocturnal hypoglycaemia was significantly lower with insulin degludec vs. insulin glargine for all hypoglycaemia definitions and trial periods. Risk was also lower for the timescale 21.59-05.59, but not 00.01-07.59. For Type 2 diabetesBB , nocturnal hypoglycaemia rates were lower with insulin degludec vs. insulin glargine across all definitions, timescales and trial periods, with one exception. For individuals with Type 1 diabetes mellitus, nocturnal hypoglycaemia risk was significantly lower with insulin degludec during the maintenance period for the original definition (plasma glucose < 3.1 mmol/l, timescale 00.01-05.59) and in the extension trial set population for all hypoglycaemia definitions except for the nocturnal timescale 00.01-07.59. CONCLUSIONS: Compared with insulin glargine, insulin degludec is associated with lower rates of nocturnal hypoglycaemia in people with Type 2 diabetes mellitus, and similar or lower rates in Type 1 diabetes mellitus, across different definitions.
Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemia/induzido quimicamente , Hipoglicemiantes/efeitos adversos , Insulina Glargina/efeitos adversos , Insulina de Ação Prolongada/efeitos adversos , Medicina de Precisão , Ritmo Circadiano , Ensaios Clínicos Fase III como Assunto , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 2/sangue , Esquema de Medicação , Humanos , Hipoglicemia/diagnóstico , Hipoglicemia/epidemiologia , Hipoglicemia/prevenção & controle , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Insulina Glargina/administração & dosagem , Insulina Glargina/uso terapêutico , Insulina de Ação Prolongada/administração & dosagem , Insulina de Ação Prolongada/uso terapêutico , Guias de Prática Clínica como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Reprodutibilidade dos Testes , RiscoRESUMO
AIMS: To determine the global extent of hypoglycaemia experienced by patients with diabetes using insulin, as there is a lack of data on the prevalence of hypoglycaemia in developed and developing countries. METHODS: This non-interventional, multicentre, 6-month retrospective and 4-week prospective study using self-assessment questionnaire and patient diaries included 27 585 patients, aged ≥18 years, with type 1 diabetes (T1D; n = 8022) or type 2 diabetes (T2D; n = 19 563) treated with insulin for >12 months, at 2004 sites in 24 countries worldwide. The primary endpoint was the proportion of patients experiencing at least one hypoglycaemic event during the observational period. RESULTS: During the prospective period, 83.0% of patients with T1D and 46.5% of patients with T2D reported hypoglycaemia. Rates of any, nocturnal and severe hypoglycaemia were 73.3 [95% confidence interval (CI) 72.6-74.0], 11.3 (95% CI 11.0-11.6) and 4.9 (95% CI 4.7-5.1) events/patient-year for T1D and 19.3 (95% CI 19.1-19.6), 3.7 (95% CI 3.6-3.8) and 2.5 events/patient-year (95% CI 2.4-2.5) for T2D, respectively. The highest rates of any hypoglycaemia were observed in Latin America for T1D and Russia for T2D. Glycated haemoglobin level was not a significant predictor of hypoglycaemia. CONCLUSIONS: We report hypoglycaemia rates in a global population, including those in countries without previous data. Overall hypoglycaemia rates were high, with large variations between geographical regions. Further investigation into these differences may help to optimize therapy and reduce the risk of hypoglycaemia.
Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemia/induzido quimicamente , Hipoglicemiantes/efeitos adversos , Insulina/efeitos adversos , Adulto , Idoso , Sudeste Asiático/epidemiologia , Canadá/epidemiologia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Europa (Continente)/epidemiologia , Europa Oriental/epidemiologia , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/epidemiologia , América Latina/epidemiologia , Masculino , Pessoa de Meia-Idade , Oriente Médio/epidemiologia , Prevalência , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco , Federação Russa/epidemiologia , Índice de Gravidade de Doença , Inquéritos e QuestionáriosRESUMO
This study aimed to observe the incidence rates of hamstring strain injuries (HSIs) across different competition levels and ages during the Penn Relays Carnival. Over a 3-year period, all injuries treated by the medical staff were recorded. The type of injury, anatomic location, event in which the injury occurred, competition level, and demographic data were documented. Absolute and relative HSI (per 1000 participants) were determined, and odds ratios (ORs) were calculated between sexes, competition levels, and events. Throughout the study period 48,473 athletes registered to participate in the Penn Relays Carnival, with 118 HSIs treated by the medical team. High school girls displayed lesser risk of HSI than high school boys (OR = 0.55, P = 0.021), and masters athletes were more likely than high school- (OR = 4.26, P < 0.001) and college-level (OR = 3.55, P = 0.001) athletes to suffer HSI. The 4 × 400-m relay displayed a greater likelihood of HSI compared with the 4 × 100-m relay (OR = 1.77, P = 0.008). High school boys and masters-level athletes are most likely to suffer HSI, and there is higher risk in 400-m events compared with 100-m events.
Assuntos
Músculo Esquelético/lesões , Corrida/lesões , Entorses e Distensões/epidemiologia , Atletismo/lesões , Adolescente , Adulto , Fatores Etários , Aniversários e Eventos Especiais , Criança , Feminino , Humanos , Masculino , Corrida/classificação , Fatores Sexuais , Coxa da Perna , Adulto JovemRESUMO
STUDY DESIGN: Prospective Pilot Study. OBJECTIVES: To determine the safety and feasibility of autologous olfactory mucosal transplantation into the spinal cord in chronic spinal cord injured using the technique developed by Carlos Lima et al. SETTING: Spinal Injury Center, New Delhi. METHODS: Five chronic, motor complete, traumatic spinal cord injury (SCI) patients with neurological level C5-T12 underwent the procedure. Participants were assessed at baseline and at 6 monthly intervals. Safety and tolerability were evaluated through monitoring for any adverse events and tests including magnetic resonance imaging (MRI) evaluation. Efficacy assessment was done through neurological, functional and psychological evaluation, electrophysiological studies and urodynamics. RESULTS: Surgery was tolerated well by all American Spinal Injury Association (ASIA) Impairment Scale (AIS) A participants. The only AIS B participant lost sensory scores significantly after surgery but is gradually regaining it. MRI evaluation revealed a syrinx in one participant and increase in length of myelomalacia in four participants. There were no other adverse findings on MRI evaluation. There was no significant improvement in any of the neurological, electrophysiological or urodynamic efficacy variables. Statistically significant improvement was seen in functional scores as evaluated by Spinal Cord Independence Measure, Beck Depression Inventory scores and life impact scores on International Spinal Cord Injury Scale. CONCLUSIONS: The procedure is relatively safe and feasible in AIS A participants with thoracic level injuries at 18 month follow-up. No efficacy could be demonstrated which could be attributed to the procedure.
Assuntos
Procedimentos Neurocirúrgicos/métodos , Mucosa Olfatória/transplante , Traumatismos da Medula Espinal/cirurgia , Medula Espinal/cirurgia , Transplante de Tecidos/métodos , Adulto , Avaliação da Deficiência , Sobrevivência de Enxerto/fisiologia , Humanos , Índia , Imageamento por Ressonância Magnética , Masculino , Regeneração Nervosa/fisiologia , Neuroglia/citologia , Neuroglia/fisiologia , Neuroglia/transplante , Exame Neurológico , Mucosa Olfatória/citologia , Mucosa Olfatória/fisiologia , Avaliação de Resultados em Cuidados de Saúde/métodos , Paralisia/etiologia , Paralisia/cirurgia , Projetos Piloto , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/patologia , Complicações Pós-Operatórias/fisiopatologia , Estudos Prospectivos , Recuperação de Função Fisiológica/fisiologia , Transtornos de Sensação/etiologia , Transtornos de Sensação/cirurgia , Índice de Gravidade de Doença , Medula Espinal/patologia , Medula Espinal/fisiopatologia , Siringomielia/etiologia , Siringomielia/patologia , Transplante Autólogo/métodos , Falha de Tratamento , Adulto JovemRESUMO
Dopamine beta-hydroxylase (DBH) catalyzes the final step in the biosynthesis of norepinephrine, the principal classic neurotransmitter of peripheral sympathetic neurons. We have shown that 5.8 kb of 5' upstream region from a cloned human DBH gene promoter is sufficient to direct expression of the E. coli lacZ gene in transgenic mice to neurons of the locus ceruleus and other classic noradrenergic brain stem nuclei, sympathetic ganglion neurons, and adrenal chromaffin cells. lacZ expression was also observed in neurons of the enteric system, the retina, some sensory and all cranial parasympathetic ganglia, and some diencephalic and telencephalic brain nuclei. The expression pattern of the transgene in DBH-immunonegative sites overlapped with many sites where expression of tyrosine hydroxylase or phenylethanolamine N-methyltransferase, two other catecholamine biosynthetic enzymes, has been reported.
Assuntos
Dopamina beta-Hidroxilase/genética , Escherichia coli/genética , Óperon Lac , Neurônios/fisiologia , Regiões Promotoras Genéticas/fisiologia , Animais , Sequência de Bases , Encéfalo/citologia , Encéfalo/fisiologia , Dopamina beta-Hidroxilase/metabolismo , Expressão Gênica/fisiologia , Humanos , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Nervos Periféricos/citologia , Nervos Periféricos/fisiologia , Sistema Nervoso Simpático/citologia , Sistema Nervoso Simpático/fisiologia , Distribuição TecidualRESUMO
The 5' flanking region from the human dopamine beta-hydroxylase gene directs expression of bacterial beta-galactosidase reporter genes to a subset of adult neurons and adrenal chromaffin cells of transgenic mice. In this paper, we examine the spatial and temporal patterns of expression of these transgenes during embryogenesis. Expression begins at embryonic day 9 in the developing central and peripheral nervous systems and persists in cell populations in which expression is observed in adult transgenic mice. However, transient embryonic expression occurs in presumptive neuroblasts in developing sensory ganglia and ventrolateral neural tube that are destined to synthesize neurotransmitters other than catecholamines. These observations support the concept that some cells fated to become "non-catecholaminergic" neurons exhibit transient catecholaminergic features during their differentiation.
Assuntos
Dopamina beta-Hidroxilase/genética , Desenvolvimento Embrionário e Fetal , Óperon Lac , Neurônios/fisiologia , Animais , Embrião de Mamíferos/fisiologia , Gânglios/fisiologia , Expressão Gênica , Idade Gestacional , Humanos , Camundongos , Camundongos Transgênicos , Sensação/fisiologia , Medula Espinal/embriologiaRESUMO
Phox2a is a vertebrate homeodomain protein expressed in subsets of differentiating neurons. Here, we show that it is essential for proper development of the locus coeruleus, a subset of sympathetic and parasympathetic ganglia and the VIIth, IXth, and Xth cranial sensory ganglia. In the sensory ganglia, we have identified two differentiation blocks in Phox2a-/- mice. First, the transient expression of dopamine-beta-hydroxylase in neuroblasts is abolished, providing evidence that Phox2a controls noradrenergic traits in vivo. Second, the expression of the GDNF receptor subunit Ret is dramatically reduced, and there is a massive increase in apoptosis of ganglion cells, which are known to depend on GDNF in vivo. Therefore, Phox2a appears to regulate conventional differentiation traits and the ability of neurons to respond to essential survival factors.
Assuntos
Proteínas de Drosophila , Gânglios Autônomos/anormalidades , Gânglios Sensitivos/anormalidades , Proteínas de Homeodomínio/fisiologia , Locus Cerúleo/anormalidades , Fatores de Crescimento Neural , Proteínas do Tecido Nervoso/fisiologia , Fatores de Transcrição/fisiologia , Animais , Apoptose , Diferenciação Celular , Nervos Cranianos/anormalidades , Nervos Cranianos/embriologia , Dopamina beta-Hidroxilase/biossíntese , Desenvolvimento Embrionário e Fetal/genética , Indução Enzimática , Feminino , Gânglios Autônomos/embriologia , Gânglios Sensitivos/embriologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial , Proteínas de Homeodomínio/genética , Locus Cerúleo/embriologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Morfogênese/genética , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Norepinefrina/fisiologia , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas c-ret , Receptores Proteína Tirosina Quinases/biossíntese , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética , TransgenesRESUMO
Plasticization of polymers by water sorption lowers their mechanical properties in a manner that is predictable by the polarity of their component resins. This study tested the hypothesis that when adhesive resins were used to create resin-infiltrated dentin, the reductions in their flexural moduli after water storage would be lowered proportional to their hydrophilic characteristics. Three increasingly hydrophilic resin blends were used to fabricate polymer beams and macro-hybrid layer models of resin-infiltrated dentin for testing with a miniature three-point flexure device, before and after 1-4 weeks of water storage. Flexural modulus reductions in macro-hybrid layers were related to, and more extensive than, reductions in the corresponding polymer beams. Macro-hybrid layers that were more hydrophilic exhibited higher percent reductions in flexural modulus, with the rate of reduction proportional to the Hoy's solubility parameters for total intermolecular attraction forces (delta(t)) and polar forces (delta(p)) of the macro-hybrid layers.
Assuntos
Adaptação Marginal Dentária , Análise do Estresse Dentário , Adesivos Dentinários/química , Dentina/química , Resinas Sintéticas/química , Análise de Variância , Dureza , Humanos , Dente Serotino , Maleabilidade , Cimentos de Resina/química , Estatísticas não Paramétricas , Estresse Mecânico , Água/química , MolhabilidadeRESUMO
OBJECT: DuraGen (Integra Neurosciences, Plainsboro, NJ, USA) is an avascular collagen matrix used for dural closure. Although, numerous animal models have been studied, histological transformation of DuraGen in humans has not been reported. MATERIAL AND METHOD: We analyzed a sample of scarred DuraGen used in a craniectomy patient at time of delayed cranioplasty. CONCLUSION: Histological analysis revealed evidence for both fibroblast infiltration and neovascularization of the DuraGen.
Assuntos
Materiais Biocompatíveis/uso terapêutico , Colágeno/uso terapêutico , Dura-Máter/cirurgia , Adolescente , Hemorragia Cerebral/etiologia , Hemorragia Cerebral/cirurgia , Descompressão Cirúrgica , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaçõesRESUMO
Toll-like receptor 4 (TLR4) mediates lipopolysaccharide (LPS) induced immune responses, which may contribute to preterm labor associated with intraamniotic gram-negative bacterial infections. The study objective was to investigate gestational age and LPS-induced changes in TLR4 subcellular localization within amniotic epithelium, the first line of host defense against intraamniotic bacteria. TLR4 localization in amniotic epithelium was assessed using immunohistochemistry on 24 placentas of different gestational ages: first trimester (n=6), second trimester (n=6), and third trimester (n=12). Immunofluorescence was used to determine TLR4 localization following ex vivo LPS stimulation of amnion from women undergoing cesarean section without labor at term. TLR4 was expressed in the cytoplasm of amniotic epithelium starting at 9weeks with apical polarization by 25weeks gestation. TLR4 localization to the basal membrane was significantly associated with chorioamnionitis (p=0.01). After LPS stimulation, TLR4 was expressed sequentially within the apical membrane, cytoplasm, and finally in the basal cellular compartment. This suggests that TLR4 expression in amniotic epithelium is poised to monitor amniotic fluid for pathogens. TLR4 translocation to the basal membrane may decrease LPS signaling early in an infection, but allow the amniotic epithelium to remain competent to invasive or intracellular bacteria.
Assuntos
Âmnio/metabolismo , Células Epiteliais/metabolismo , Lipopolissacarídeos/farmacologia , Placenta/metabolismo , Receptor 4 Toll-Like/metabolismo , Âmnio/citologia , Âmnio/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Feminino , Humanos , Imuno-Histoquímica , Cinética , Microscopia Confocal , Placenta/citologia , Placenta/efeitos dos fármacos , Gravidez , Transporte ProteicoRESUMO
The use of TEGDMA as a diluent comonomer in the formulation of hydrophobic adhesives for ethanol wet-bonding is a concern, due to its leaching potential, higher water sorption, and bio-incompatibility. This study tested the hypothesis that hydrophobic bonding to acid-etched dentin may be accomplished with the use of ethanol-solvated BisGMA only. Phosphoric-acid-etched, oxalate-occluded, deep coronal dentin bonded under 20 cm water pressure with experimental BisGMA adhesives by ethanol wet-bonding exhibited tensile strengths that were not significantly different from that achieved with OptiBond FL bonded according to the manufacturer-recommended protocol, with similar acid-/base-resistant hybrid layers, resin tags, and nanoleakage distribution. Ethanol replacement of water-saturated dentin produced wider interfibrillar spaces, more extensive shrinkage of the collagen fibrils, and narrower hybrid layers. Experimental BisGMA adhesives provide the proof of concept that relatively hydrophobic resins may be coupled to acid-etched dentin by increasing its hydrophobic characteristics via ethanol replacement. They should be further optimized before clinical application.
Assuntos
Bis-Fenol A-Glicidil Metacrilato/química , Colagem Dentária/métodos , Adesivos Dentinários/química , Dentina/química , Cimentos de Resina/química , Condicionamento Ácido do Dente , Análise do Estresse Dentário , Permeabilidade da Dentina , Etanol , Humanos , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Dente Serotino , Solventes , Resistência à TraçãoRESUMO
p27(Kip1) is a member of the Cip-Kip family of cyclin-dependent kinase (Cdk) inhibitors that binds to cyclin-Cdk complexes and inhibits their catalytic activity in response to antiproliferative stimuli. p27(Kip1) is regulated by several posttranscriptional mechanisms, including subcellular localization. We have identified a component of the nuclear pore complex (NPC), termed Nup50, through its two-hybrid interactions with p27(Kip1). Nup50 is a nucleoplasmically oriented component of the nuclear pore complex with a role in protein export (T. Guan, R. H. Kehlenbach, E. C. Schirmer, A. Kehlenbach, F. Fan, B. E. Clurman, N. Arnheim, and L. Gerace, Mol. Cell. Biol. 20:5619-5630, 2000). We found that murine Nup50 is a widely expressed nucleoporin and that Nup50 expression is highest in the developing neural tube and adult testes. We have also examined interactions between Nup50 and the NPC and found specific two-hybrid interactions between Nup50 and several well-defined components of the NPC, as well as coimmunoprecipitation of Nup50 with the nucleoporin Nup153 from transfected mammalian cells. In order to study Nup50 function in vivo, we cloned the mouse Nup50 genomic locus and created a targeted Nup50 deletion in the mouse germ line. Nup50 disruption resulted in a complex phenotype characterized by late embryonic lethality, neural tube defects, and intrauterine growth retardation. Although Nup50-null mouse embryo fibroblasts exhibited no defects in either cell cycle control or p27(Kip1) regulation, Nup50 deletion was associated with abnormalities in p27(Kip1) expression and cell proliferation in the developing neuroepithelium. We conclude that Nup50 is a nucleoporin with essential functions during mouse development.
Assuntos
Proteínas de Ciclo Celular , Núcleo Celular/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Porinas/genética , Porinas/metabolismo , Proteínas Supressoras de Tumor , Sequência de Aminoácidos , Animais , Núcleo Celular/ultraestrutura , Clonagem Molecular , Inibidor de Quinase Dependente de Ciclina p27 , Morte Fetal/genética , Retardo do Crescimento Fetal/genética , Fibroblastos , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Dados de Sequência Molecular , Defeitos do Tubo Neural/genética , Testes de PrecipitinaRESUMO
BACKGROUND: Osteopetrosis, a genetic disease characterised by osteoclast failure, is classified into three forms: infantile malignant autosomal recessive osteopetrosis (ARO), intermediate autosomal recessive osteopetrosis (IRO), and autosomal dominant osteopetrosis (ADO). METHODS: We studied 49 patients, 21 with ARO, one with IRO, and 27 with type II ADO (ADO II). RESULTS: Most ARO patients bore known or novel (one case) ATP6i (TCIRG1) gene mutations. Six ADO II patients had no mutations in ClCN7, the only so far recognised gene implicated, suggesting involvement of yet unknown genes. Identical ClCN7 mutations produced differing phenotypes with variable degrees of severity. In ADO II, serum tartrate resistant acid phosphatase was always elevated. Bone alkaline phosphatase (BALP) was generally low, but osteocalcin was high, suggesting perturbed osteoblast differentiation or function. In contrast, BALP was high in ARO patients. Elevated osteoclast surface/bone surface was noted in biopsies from most ARO patients. Cases with high osteoclasts also showed increased osteoblast surface/bone surface. ARO osteoclasts were morphologically normal, with unaltered formation rates, intracellular pH handling, and response to acidification. Their resorption activity was greatly reduced, but not abolished. In control osteoclasts, all resorption activity was abolished by combined inhibition of proton pumping and sodium/proton antiport. CONCLUSIONS: These findings provide a rationale for novel therapies targeting pH handling mechanisms in osteoclasts and their microenvironment.
Assuntos
Canais de Cloreto/genética , Osteopetrose/diagnóstico , Osteopetrose/genética , ATPases Vacuolares Próton-Translocadoras/genética , Adolescente , Adulto , Fosfatase Alcalina/sangue , Reabsorção Óssea/metabolismo , Reabsorção Óssea/patologia , Criança , Pré-Escolar , Canais de Cloreto/química , Feminino , Genótipo , Humanos , Concentração de Íons de Hidrogênio , Masculino , Osteocalcina/sangue , Osteoclastos/patologia , Osteoclastos/fisiologia , Osteopetrose/terapia , Monoéster Fosfórico Hidrolases/sangue , Trocadores de Sódio-Hidrogênio/fisiologiaRESUMO
Dipeptidylpeptidase 4 (DPP4/CD26) enzymatically cleaves select penultimate amino acids of proteins, including colony-stimulating factors (CSFs), and has been implicated in cellular regulation. To better understand the role of DPP4 regulation of hematopoiesis, we analyzed the activity of DPP4 on the surface of immature blood cells and then comparatively assessed the interactions and functional effects of full-length (FL) and DPP4 truncated (T) factors (T-granulocyte-macrophage-CSF (T-GM-CSF)) and T-interleukin-3 (T-IL-3)) on both in vitro and in vivo models of normal and leukemic cells. T-GM-CSF and -IL-3 had enhanced receptor binding, but decreased CSF activity, compared with their FL forms. Importantly, T-GM-CSF and -IL-3 significantly, and reciprocally, blunted receptor binding and myeloid progenitor cell proliferation activity of both FL-GM-CSF and -IL-3 in vitro and in vivo. Similar effects were apparent in vitro using cluster-forming cells from patients with acute myeloid leukemia regardless of cytogenetic or molecular alterations and in vivo using animal models of leukemia. This suggests that DPP4 T-molecules have modified binding and functions compared with their FL counterparts and may serve regulatory roles in normal and malignant hematopoiesis.
Assuntos
Dipeptidil Peptidase 4/metabolismo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Interleucina-3/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Proliferação de Células , Humanos , Leucemia Mieloide Aguda/patologia , Camundongos , Camundongos Endogâmicos C57BL , Ligação ProteicaRESUMO
Sympathetic neurons, enteric neurons and adrenal chromaffin cells all derive from the neural crest. During development these cells migrate, proliferate, survive and differentiate in a highly controlled fashion influenced by local signals encountered during their migration. Aberrations of these processes are responsible for a variety of developmental defects and malignancies. Many of the environmental signals influencing these precursor cells activate receptor tyrosine kinases that can signal, at least in part, via Ras pathways. To assess the extent to which Ras can alter neuroblast cell number and fate in vivo, we expressed activated H-Ras in transgenic mice using the dopamine-beta-hydroxylase promoter, which directs expression to these cells prior to and after their differentiation. Ganglioneuromas and occasional neuroblastomas formed in the adrenal gland and preaortic sympathetic ganglia. Curiously, neurons of the superior cervical ganglia and the gut were largely unaffected despite demonstrated expression of activated Ras. The sensitivity of preaortic sympathetic neurons and adrenal chromaffin cells to the effects of oncogenes such as Ras may explain the predilection of neuroblastomas in humans to these sites. The ability to analyse neuroblastoma development in these mice may shed light on the molecular basis of certain types of human neuroblastoma.
Assuntos
Transformação Celular Neoplásica/patologia , Neurônios/patologia , Proteínas ras/metabolismo , Glândulas Suprarrenais/patologia , Medula Suprarrenal/inervação , Medula Suprarrenal/patologia , Aneuploidia , Animais , Diferenciação Celular , Transformação Celular Neoplásica/metabolismo , Aberrações Cromossômicas/genética , Transtornos Cromossômicos , Dopamina beta-Hidroxilase/genética , Feminino , Gânglios Simpáticos/patologia , Genes myc , Humanos , Hiperplasia , Cariotipagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Transgênicos , Neuritos/patologia , Neuroblastoma/genética , Neurônios/metabolismo , RNA Mensageiro/metabolismo , Transdução de Sinais/genética , Proteínas ras/genéticaRESUMO
Multiple endocrine neoplasia type 2B (MEN2B) is an autosomal dominant syndrome characterized by the development of medullary thyroid carcinoma, pheochromocytomas, musculoskeletal anomalies and mucosal ganglioneuromas. MEN2B is caused by a specific mutation (Met918-->Thr) in the RET receptor tyrosine kinase. Different mutations of RET lead to other conditions including MEN2A, familial medullary thyroid carcinoma and intestinal aganglionosis (Hirschsprung disease). Transgenic mice were created using the dopamine beta-hydroxylase promoter to direct expression of RET(MEN2B) in the developing sympathetic and enteric nervous systems and the adrenal medulla. DbetaH-RET(MEN2B) transgenic mice developed benign neuroglial tumors, histologically identical to human ganglioneuromas, in their sympathetic nervous systems and adrenal glands. The enteric nervous system was not affected. The neoplasms in DbetaH-RET(MEN2B) mice were similar to benign neuroglial tumors induced in transgenic mice by activated Ras expression under control of the same promoter. Levels of phosphorylated MAP kinase were not increased in the RET(MEN2B)-induced neurolglial proliferations, suggesting that alternative pathways may play a role in the pathogenesis of these lesions. Transgenic mice with the highest levels of DbetaH-RET(MEN2B) expression, unexpectedly developed renal malformations analogous to those reported with loss of function mutations in the Ret gene.
Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Proteínas de Drosophila , Ganglioneuroma/genética , Regulação da Expressão Gênica , Rim/anormalidades , Neoplasia Endócrina Múltipla Tipo 2a/genética , Proteínas Proto-Oncogênicas/genética , Receptores Proteína Tirosina Quinases/genética , Sistema Nervoso Simpático , Glândulas Suprarrenais/inervação , Glândulas Suprarrenais/patologia , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Humanos , Hiperplasia/genética , Camundongos , Camundongos Transgênicos , Neoplasias do Sistema Nervoso Periférico/genética , Proteínas Proto-Oncogênicas c-ret , Sistema Nervoso Simpático/patologiaRESUMO
In psychiatry mental health nurses form the largest professional discipline providing care on an everyday basis for sustained periods. Mental health nurses therefore are in a pivotal position to establish valued therapeutic alliances. In practice, however, a disproportionate amount of nursing time is taken up by administration, time spent talking to patients is minimal and when interactions do occur they remain notionally therapeutic and often are not theoretically informed. This noted paucity of therapeutic contact is antithetical to the aspirations of service users who increasingly are asking for a more skilled approach to the talking-listening that occurs in the therapeutic encounter. It is hypothesized by the present authors that an object-relations perspective of the nurse-patient relationship could release the largely untapped therapeutic potential of the psychiatric nurse by (1) bridging the gap between theory and practice and (2) providing a professional identity from within which nurses can begin to 'get to know' and understand the predicament of the patient with severe mental illness.