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1.
Clin Radiol ; 78(12): e941-e949, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37788968

RESUMO

AIM: To investigate how magnetic resonance imaging (MRI) examinations are protocolled in tertiary paediatric neuroradiology centres around the UK for some of the more common presentations encountered in paediatric neuroradiology, and to identify any variations of note. MATERIALS AND METHODS: All 19 UK tertiary paediatric neuroradiology centres registered with the British Society of Neuroradiologists-Paediatric Group were contacted and asked if they could provide a copy of their standard MRI protocols. Twelve responded (63%) and 10 of the more common presentations were selected and the standard acquired sequences obtained at each participating centre were compared. Where available the collated protocols were also compared against current published guidance. RESULTS: The basic sequences carried out by centres around the UK are similar; however, there are lots of variations overall. The only standardised protocol currently being implemented nationally in paediatric imaging is that for brain tumours. Otherwise, chosen protocols are generally dependent on the preferences and technical capabilities of individual centres. Suggested published protocols also exist for non-accidental injury (NAI), multiple sclerosis, epilepsy, and head and neck imaging. CONCLUSIONS: The differences in MRI protocolling depend in part on technical capabilities and in part on the experience and preferences of the paediatric neuroradiologists at each centre. For most presentations, there is no consensus as to what constitutes the perfect protocol. The present results will be useful for specialist centres who may wish to review their current protocols, and for more generalist centres to use as a reference to guide their MRI protocolling.


Assuntos
Neoplasias Encefálicas , Hospitais Pediátricos , Criança , Humanos , Neoplasias Encefálicas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Centros de Atenção Terciária , Reino Unido
2.
Cytometry B Clin Cytom ; 94(6): 935-940, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30350400

RESUMO

BACKGROUND: Bone marrow (BM) aspirate analysis by flow cytometry (FC) is a key hematopathologic technique but dry taps hinder diagnosis. We describe the utility and limitations of a method of mechanically disaggregating BM trephine biopsies for FC. METHOD: Trephine biopsies mechanically disaggregated for FC between 2010 and 2016 were reviewed. We recorded cell yield, pathological findings, and turnaround time. Where available, results of trephine FC were compared with aspirate FC. RESULTS: Eighty BM trephine samples were processed, representing 4.3% of BM biopsies. Mechanical disaggregation yielded cellular samples in 98% of cases (median yield 3 × 106 nucleated cells). The most frequent diagnoses were B cell lymphoproliferative disorders (n = 26) and acute leukemia (n = 18). Trephine FC correlated with histochemistry findings in 94% of cases, but two Hodgkin lymphoma infiltrates were missed by FC, and trephine FC underestimated B cell infiltrate burden compared to immunohistochemistry (IHC). Fluorescence intensity of CD34 and CD45 on disease populations was similar in processed trephine and contemporaneous aspirate samples. Trephine FC results were available 2 days earlier than stained IHC slides. CONCLUSION: Mechanical disaggregation of BM trephine samples provided a cellular suspension suitable for diagnostic FC in most cases. Limitations were similar to aspirate FC: disease burden was underestimated and some infiltrates were missed. Trephine FC results were available earlier than trephine IHC. We conclude that trephine FC is a useful technique to complement trephine IHC in the event of a failed aspirate, providing rapid diagnostic immunophenotyping. © 2018 International Clinical Cytometry Society.


Assuntos
Biópsia , Medula Óssea/patologia , Citometria de Fluxo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Medula Óssea/imunologia , Exame de Medula Óssea , Feminino , Humanos , Imuno-Histoquímica , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
3.
Theriogenology ; 107: 95-103, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29145066

RESUMO

The search for non-invasive signs of oocyte meiotic competence is very important for the development of in vitro follicle culture (IVFC) systems. The aims of the present study were: (1) to investigate the effect of in vitro maturation (IVM) of in vivo grown goat COCs, in group or individually, on oocyte chromatin configuration (Experiment 1), and (2) the influence of IVFC period (12 vs. 18 days) on the ability of the oocyte to resume meiosis immediately after IVFC (before in vitro maturation; IVM), or after IVM (Experiment 2). In experiment 1, in vivo grown cumulus-oocyte complexes (COCs) were submitted to IVM in groups (10 COCs/100 µL-drop) or individually (1 COC/10 µL-drop), and chromatin configuration was assessed. In experiment 2, isolated follicles were individually cultured for 12 or 18 days, and submitted to individual IVM afterwards. The following end points were evaluated: follicular growth and morphology, oocyte diameter, viability and chromatin configuration, as well as individual follicular estradiol production. Similar maturation rates were obtained between in vivo grown COCs matured individually and in groups (66.7% vs. 63.6%, respectively) (Experiment 1). Only after 18 days of IVFC, oocytes were able to grow during IVM, reaching a mean oocyte diameter of 119 µm. Also, this treatment produced the highest rate of metaphase II oocytes (46.2% out of the total number of cultured follicles). Finally, it was observed that follicles with a daily growth rate >7.1 µm/day (fast-growing) and that reached at least 600 µm in diameter, were more likely (P < 0.05) to produce oocytes capable of attaining MII. In conclusion, caprine oocytes can be individually matured in vitro, as efficiently as in groups. This result was essential to pair in vitro follicle development and in vitro oocyte maturation with specific individual follicles. Using this approach, it was possible to establish non-invasive signs for the efficiency of IVFC based on follicle daily growth rate and diameter, and oocyte diameter: follicle daily growth >7 µm, follicle diameter of at least 600 µm, and oocyte diameter ≥120 µm. In addition, 18 days seems to be the most suitable culture time for caprine early antral follicles.


Assuntos
Cabras/fisiologia , Técnicas de Maturação in Vitro de Oócitos/veterinária , Meiose/fisiologia , Oócitos/fisiologia , Folículo Ovariano/fisiologia , Animais , Tamanho Celular , Cromatina , Estradiol/metabolismo , Feminino , Oócitos/citologia
4.
Int J Obes (Lond) ; 41(1): 149-158, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27773938

RESUMO

BACKGROUND: Consumption of dietary fat is one of the key factors leading to obesity. High-fat diet (HFD)-induced obesity is characterized by induction of inflammation in the hypothalamus; however, the temporal regulation of proinflammatory markers and their impact on hypothalamic appetite-regulating neuropeptide Y/agouti-related peptide (NPY/AgRP) neurons remains undefined. METHODS: Mice were injected with an acute lipid infusion for 24 h or fed a HFD over 8-20 weeks. Characterized mouse NPY/AgRP hypothalamic cell lines were used for in vitro experimentation. Immunohistochemistry in brain slices or quantitative real-time PCR in cell lines, was performed to determine changes in the expression of key inflammatory markers and neuropeptides. RESULTS: Hypothalamic inflammation, indicated by tumor necrosis factor (TNF)-α expression and astrocytosis in the arcuate nucleus, was evident following acute lipid infusion. HFD for 8 weeks suppressed TNF-α, while significantly increasing heat-shock protein 70 and ciliary neurotrophic factor, both neuroprotective components. HFD for 20 weeks induced TNF-α expression in NPY/AgRP neurons, suggesting a detrimental temporal regulatory mechanism. Using NPY/AgRP hypothalamic cell lines, we found that palmitate provoked a mixed inflammatory response on a panel of inflammatory and endoplasmic reticulum (ER) stress genes, whereas TNF-α significantly upregulated IκBα, nuclear factor (NF)-κB and interleukin-6 mRNA levels. Palmitate and TNF-α exposure predominantly induced NPY mRNA levels. Utilizing an I kappa B kinase ß (IKKß) inhibitor, we demonstrated that these effects potentially occur via the inflammatory IKKß/NF-κB pathway. CONCLUSIONS: These findings indicate that acute lipid and chronic HFD feeding in vivo, as well as acute palmitate and TNF-α exposure in vitro, induce markers of inflammation or ER stress in the hypothalamic appetite-stimulating NPY/AgRP neurons over time, which may contribute to a dramatic alteration in NPY/AgRP content or expression. Acute and chronic HFD feeding in vivo temporally regulates arcuate TNF-α expression with reactive astrocytosis, which suggests a time-dependent neurotrophic or neurotoxic role of lipids.


Assuntos
Apetite/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Hipotálamo/patologia , Inflamação/induzido quimicamente , Neurônios/efeitos dos fármacos , Neuropeptídeo Y/metabolismo , Palmitatos/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Animais , Núcleo Arqueado do Hipotálamo/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica , Hipotálamo/efeitos dos fármacos , Inflamação/patologia , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Obesidade/patologia
5.
Reprod Fertil Dev ; 29(6): 1144-1154, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27166082

RESUMO

The aim of the present study was to evaluate the effect of anti-Müllerian hormone (AMH), with and without FSH, on the in vitro development of isolated caprine preantral follicles, as well as follicular steroid production and mRNA levels of AMH, hormone receptors (AMH and FSH), CYP19A1 (cytochrome P450, family 19, subfamily A, polypeptide 1), CYP17 (cytochrome P450, family 17, subfamily A, polypeptide 1), HSD3B (3-beta-hydroxysteroid dehydrogenase) and Myc (myelocytomatosis oncogene). Isolated secondary follicles were cultured in minimum essential medium alpha (α-MEM+) alone or supplemented with 50ng mL-1 AMH and/or 100ng mL-1 FSH added sequentially on different days of culture. Follicles were cultured for a total of 18 days, with different media during the first (Days 0-9) and second (Days 10-18) halves of the culture period, resulting in six treatment groups, as follows: α-MEM+/α-MEM+, FSH/FSH, AMH/AMH, AMH+FSH/AMH+FSH, AMH/FSH, and FSH/AMH. Follicle development was evaluated on the basis of follicular growth, oocyte maturation and steroid secretion. There was a decrease in follicular growth rate in the AMH, AMH+FSH and AMH/FSH treatment groups compared with α-MEM+ and FSH treatment groups (P<0.05). However, the different culture conditions had no effect on rates of meiotic resumption and steroid secretion (P>0.05). Moreover, follicles cultured in the presence of FSH had lower levels of AMH receptor type II (AMHRII) mRNA compared with non-cultured control (freshly isolated follicles), and the AMH and AMH/FSH treatment groups. In conclusion, AMH reduces the follicular growth rate of isolated goat preantral follicles in vitro without affecting follicular survival.


Assuntos
Hormônio Antimülleriano/metabolismo , Hormônio Foliculoestimulante/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Oogênese , Folículo Ovariano/metabolismo , Receptores do FSH/agonistas , Receptores de Peptídeos/agonistas , Receptores de Fatores de Crescimento Transformadores beta/agonistas , Matadouros , Animais , Hormônio Antimülleriano/genética , Hormônio Antimülleriano/farmacologia , Brasil , Bovinos , Proliferação de Células/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cruzamentos Genéticos , Estradiol/metabolismo , Feminino , Hormônio Foliculoestimulante/genética , Hormônio Foliculoestimulante/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Cabras , Humanos , Oogênese/efeitos dos fármacos , Folículo Ovariano/citologia , Folículo Ovariano/efeitos dos fármacos , Progesterona/metabolismo , Receptores do FSH/genética , Receptores do FSH/metabolismo , Receptores de Peptídeos/genética , Receptores de Peptídeos/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Testosterona/metabolismo , Técnicas de Cultura de Tecidos
6.
J Occup Environ Hyg ; 12 Suppl 1: S7-17, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26252067

RESUMO

Virtually no occupational exposure standards specify the level of risk for the prescribed exposure, and most occupational exposure limits are not based on quantitative risk assessment (QRA) at all. Wider use of QRA could improve understanding of occupational risks while increasing focus on identifying exposure concentrations conferring acceptably low levels of risk to workers. Exposure-response modeling between a defined hazard and the biological response of interest is necessary to provide a quantitative foundation for risk-based occupational exposure limits; and there has been considerable work devoted to establishing reliable methods quantifying the exposure-response relationship including methods of extrapolation below the observed responses. We review several exposure-response modeling methods available for QRA, and demonstrate their utility with simulated data sets.


Assuntos
Exposição Ocupacional/história , Saúde Ocupacional/história , Medição de Risco/métodos , Métodos Epidemiológicos , História do Século XX , Humanos , Modelos Estatísticos , Nível de Efeito Adverso não Observado , Exposição Ocupacional/normas , Saúde Ocupacional/normas
7.
Diabetes Obes Metab ; 17(10): 1003-6, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26095311

RESUMO

Increasing evidence points to the cytotoxicity of islet amyloid polypeptide (IAPP) aggregates as a major contributor to the loss of ß-cell mass in type 2 diabetes. Prevention of IAPP formation represents a potential treatment to increase ß-cell survival and function. The IAPP inhibitory peptide, D-ANFLVH, has been previously shown to prevent islet amyloid accumulation in cultured human islets. To assess its activity in vivo, D-ANFLVH was administered by intraperitoneal injection into a human IAPP transgenic mouse model, which replicates type 2 diabetes islet amyloid pathology. The peptide was a potent inhibitor of islet amyloid deposition, resulting in reduced islet cell apoptosis and preservation of ß-cell area leading to improved glucose tolerance. These findings provide support for a key role of islet amyloid in ß-cell survival and validate the application of anti-amyloid compounds as therapeutic strategies to maintain normal insulin secretion in patients with type 2 diabetes.


Assuntos
Glicemia/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Homeostase/efeitos dos fármacos , Polipeptídeo Amiloide das Ilhotas Pancreáticas/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Tipo 2/sangue , Modelos Animais de Doenças , Células Secretoras de Insulina/efeitos dos fármacos , Polipeptídeo Amiloide das Ilhotas Pancreáticas/uso terapêutico , Ilhotas Pancreáticas/efeitos dos fármacos , Camundongos , Camundongos Transgênicos
8.
Am J Transplant ; 15(3): 650-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25648766

RESUMO

We conducted a review of patients undergoing heart transplantation (HT) at our institution for amyloid cardiomyopathy (ACM) between 2008 and 2013. Complete follow-up was available for all patients. Nineteen patients with ACM underwent HT during the study period, accounting for 9.4% of all HT performed at our institution during this period. Amyloid subtype was light chain (AL) in 9 patients and transthyretin (ATTR) in 10 (2 wild-type, 7 familial, 1 unknown). Eight of nine patients with AL amyloidosis began chemotherapy prior to HT, six have resumed chemotherapy since HT, and five have undergone autologous stem cell transplantation. Most recent free light chain levels in AL patients decreased by a median of 85% from peak values. Only one patient developed recurrent graft amyloidosis, occurring at 3.5 years post-HT and asymptomatic. After a median follow-up of 380 days, 17 (89.5%) patients are alive. To our knowledge, this is the largest single-center series reported of ACM patients undergoing HT in the modern era. Our results suggest that acceptable outcomes following HT can be achieved in the short-to-intermediate term and that this is a feasible option for end-stage ACM with careful patient selection and aggressive control of amyloidogenic light chains in AL patients.


Assuntos
Amiloidose/complicações , Cardiomiopatias/cirurgia , Transplante de Coração , Resultado do Tratamento , Idoso , Cardiomiopatias/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Bioresour Technol ; 173: 177-184, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25305646

RESUMO

Pine sawdust was pretreated with several calcium compounds and then pyrolyzed in a fluidized bed pyrolysis reactor at 500 °C. The catalytic action of the calcium compounds varies depending on the anion. Analysis of pyrolysis gas, liquid and char yields and compositions demonstrates that calcium sulfate is inert during pyrolysis while calcium formate, carbonate, hydroxide and oxide show significant deoxygenation activity. Of the salts which showed deoxygenation activity, calcium formate had the highest relative yield. This effect is likely attributable to the activity of calcium formate as a hydrogen donor at the pyrolysis temperature.


Assuntos
Formiatos/química , Óleos/química , Oxigênio/isolamento & purificação , Pinus/química
10.
Mol Endocrinol ; 27(9): 1550-63, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23864651

RESUMO

Glucagon-like peptide 1 receptor (GLP-1R) controls diverse physiological functions in tissues including the pancreatic islets, brain, and heart. To understand the mechanisms that control glucagon-like peptide 1 (GLP-1) signaling better, we sought to identify proteins that interact with the GLP-1R using a membrane-based split ubiquitin yeast two-hybrid (MYTH) assay. A screen of a human fetal brain cDNA prey library with an unliganded human GLP-1R as bait in yeast revealed 38 novel interactor protein candidates. These interactions were confirmed in mammalian Chinese hamster ovarian cells by coimmunoprecipitation. Immunofluorescence was used to show subcellular colocalization of the interactors with GLP-1R. Cluster analysis revealed that the interactors were primarily associated with signal transduction, metabolism, and cell development. When coexpressed with the GLP-1R in Chinese hamster ovarian cells, 15 interactors significantly altered GLP-1-induced cAMP accumulation. Surprisingly, all 15 proteins inhibited GLP-1-activated cAMP. Given GLP-1's prominent role as an incretin, we then focused on 3 novel interactors, SLC15A4, APLP1, and AP2M1, because they are highly expressed and localized to the membrane in mouse insulinoma ß-cells. Small interfering RNA-mediated knockdown of each candidate gene significantly enhanced GLP-1-induced insulin secretion. In conclusion, we have generated a novel GLP-1R-protein interactome, identifying several interactors that suppress GLP-1R signaling. We suggest that the inhibition of these interactors may serve as a novel strategy to enhance GLP-1R activity.


Assuntos
Mapas de Interação de Proteínas , Receptores de Glucagon/metabolismo , Animais , Células CHO , Cricetinae , Cricetulus , AMP Cíclico/metabolismo , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Receptor do Peptídeo Semelhante ao Glucagon 1 , Células HEK293 , Humanos , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Camundongos , Ligação Proteica/efeitos dos fármacos , Mapas de Interação de Proteínas/efeitos dos fármacos , Reprodutibilidade dos Testes , Técnicas do Sistema de Duplo-Híbrido , Ubiquitina/metabolismo
11.
Diabetologia ; 55(2): 358-71, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22075915

RESUMO

AIMS/HYPOTHESIS: Using a novel directed differentiation protocol, we recently generated up to 25% insulin-producing cells from human embryonic stem cells (hESCs) (insulin(+) cells). At this juncture, it was important to functionally and molecularly characterise these hESC-derived insulin(+) cells and identify key differences and similarities between them and primary beta cells. METHODS: We used a new reporter hESC line with green fluorescent protein (GFP) cDNA targeted to the INS locus by homologous recombination (INS (GFP/w)) and an untargeted hESC line (HES2). INS (GFP/w) allowed efficient identification and purification of GFP-producing (INS:GFP(+)) cells. Insulin(+) cells were examined for key features of adult beta cells using microarray, quantitative PCR, secretion assays, imaging and electrophysiology. RESULTS: Immunofluorescent staining showed complete co-localisation of insulin with GFP; however, cells were often multihormonal, many with granules containing insulin and glucagon. Electrophysiological recordings revealed variable K(ATP) and voltage-gated Ca(2+) channel activity, and reduced glucose-induced cytosolic Ca(2+) uptake. This translated into defective glucose-stimulated insulin secretion but, intriguingly, appropriate glucagon responses. Gene profiling revealed differences in global gene expression between INS:GFP(+) cells and adult human islets; however, INS:GFP(+) cells had remarkably similar expression of endocrine-lineage transcription factors and genes involved in glucose sensing and exocytosis. CONCLUSIONS/INTERPRETATION: INS:GFP(+) cells can be purified from differentiated hESCs, providing a superior source of insulin-producing cells. Genomic analyses revealed that INS:GFP(+) cells collectively resemble immature endocrine cells. However, insulin(+) cells were heterogeneous, a fact that translated into important functional differences within this population. The information gained from this study may now be used to generate new iterations of functioning beta cells that can be purified for transplant.


Assuntos
Células-Tronco Embrionárias/citologia , Células Secretoras de Insulina/citologia , Insulina/metabolismo , Trifosfato de Adenosina/química , Adulto , Animais , Cálcio/metabolismo , Eletrofisiologia/métodos , Proteínas de Fluorescência Verde/metabolismo , Humanos , Ilhotas Pancreáticas/citologia , Camundongos , Microscopia de Fluorescência/métodos , Análise de Sequência com Séries de Oligonucleotídeos , Pâncreas/embriologia , Potássio/metabolismo , Fatores de Tempo
12.
Br J Surg ; 98(5): 686-96, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21381002

RESUMO

BACKGROUND: Obese patients with type II diabetes who undergo bariatric surgery revert to normal blood glucose and insulin levels, and develop a dramatic increase in insulin sensitivity. However, the mechanisms involved are unknown. This study characterized pancreatic islet and duodenojejunal enteroendocrine cells in normal mice and those with diabetes induced by a high-fat diet (HFD) following duodenojejunal bypass (DJB). METHODS: C57BL/6J mice, fed for 8 weeks either a normal diet (n = 10) or a HFD (n = 10) resulting in a hyperglycaemic state, underwent DJB (connection of the distal end of the jejunum to the distal stomach and direction of biliopancreatic secretions to the distal jejunum). Metabolic and immunohistological analyses were carried out on the pancreas and gastrointestinal tract. RESULTS: A significant decrease in fasting blood glucose was observed in normal-DJB and HFD-DJB mice 1 week after the operation, with improved glucose tolerance at 4 weeks. There were no changes in pancreatic ß-cell mass, but an increase in the ratio of α-cell to ß-cell mass was observed in the DJB groups. Furthermore, the number of cells expressing Pdx-1, glucagon-like peptide 1, pancreatic polypeptide and synaptophysin was increased in the bypassed duodenum and/or gastrojejunum of the DJB groups. CONCLUSION: Both normal and obese diabetic mice that underwent DJB displayed improved glucose tolerance and a reduction in fasting blood glucose, which mimicked findings in obese diabetic patients following bariatric surgery. The present data suggest that an increase in specific enteroendocrine cell populations may play a critical role in normalizing glucose homeostasis.


Assuntos
Diabetes Mellitus Tipo 2/cirurgia , Gorduras na Dieta/administração & dosagem , Duodeno/cirurgia , Jejuno/cirurgia , Anastomose Cirúrgica , Animais , Glicemia/metabolismo , Peso Corporal , Colecistocinina/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/patologia , Dieta/efeitos adversos , Ingestão de Alimentos , Imunofluorescência , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Proteínas de Homeodomínio/metabolismo , Homeostase , Ilhotas Pancreáticas/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Transativadores/metabolismo
13.
Theriogenology ; 75(8): 1381-99, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21354606

RESUMO

Bone is a plastic tissue with a large healing capability. However, extensive bone loss due to disease or trauma requires tissue-engineering applications. Presently, bone grafting is the gold standard for bone repair, but presents serious limitations including donor site morbidity, rejection, and limited tissue regeneration. The use of stem cells appears to be a means to overcome such limitations. Bone marrow mesenchymal stem cells (BMSC) have been the choice, thus far, for stem cell therapy for bone regeneration. However, it has been shown that adipose-derived stem cells (ASC) have similar immunophenotype, morphology, multilineage potential, and transcriptome compared to BMSC. Moreover, ASC are much more abundant, more accessible and have lower donor morbidity, which combined may make ASC a better alternative to BMSC. ASC are also able to migrate to the site of injury and have immunosuppressive abilities similar to BMSC. Further, ASC have demonstrated extensive osteogenic capacity both in vitro and in vivo in several species, greatly enhancing the healing of critical size defects. The use of scaffolds in combination with ASC and growth factors provides a valuable tool for guided bone regeneration, especially for complex anatomic defects. Some critical elements include ASC-scaffold interactions and appropriate three-dimensional design of the porous osteoinductive structures. This review examines data that provides strong support for the clinical translation of ASC for bone regeneration.


Assuntos
Tecido Adiposo/citologia , Regeneração Óssea/fisiologia , Transplante Ósseo/métodos , Células-Tronco Mesenquimais/fisiologia , Suínos/fisiologia , Engenharia Tecidual/métodos , Animais
14.
Spinal Cord ; 46(1): 21-5, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17406379

RESUMO

STUDY DESIGN: Retrospective chart review. OBJECTIVES: To determine the prevalence of fatigue in an outpatient spinal cord injury population and to examine the clinical variables contributing to that fatigue. SETTING: GF Strong Rehabilitation Centre, Vancouver, British Columbia, Canada. METHODS: Medical charts of 76 individuals admitted to the GF Strong Outpatient SCI Program between December 2004 and December 2005 were reviewed. Data collected included information on clinical characteristics, demographics and Fatigue Severity Scale (FSS) scores. Multivariable analysis was completed to determine the independent association between these variables and fatigue severity. RESULTS: A total of 57% (95% confidence interval (CI)=45-67%) of the sample were found to have fatigue severe enough to interfere with function. People that were admitted for medical reasons; had pain, spasticity, incomplete injuries, and/or were on more that one medication with a known side effect of fatigue had significantly higher FSS scores. Multivariable analysis indicated incomplete injury was the only statistically significant predictor of a higher FSS scores; pain approached significance (P=0.07, CI=-0.09, 2.06). Together these variables account for 18% of the variance in FSS scores in this sample. CONCLUSION: Fatigue among individuals with spinal cord injury who are seeking outpatient rehabilitation is very common. The severity of fatigue was greater for individuals with incomplete lesions. Pain was also a potentially important covariate of fatigue. Further research is required to determine what else contributes to fatigue severity beyond these clinical variables as only minimal variance was accounted for in our model.


Assuntos
Síndrome de Fadiga Crônica/epidemiologia , Traumatismos da Medula Espinal/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Analgésicos/efeitos adversos , Comorbidade , Síndrome de Fadiga Crônica/psicologia , Feminino , Humanos , Escala de Gravidade do Ferimento , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Espasticidade Muscular/tratamento farmacológico , Espasticidade Muscular/epidemiologia , Espasticidade Muscular/psicologia , Medição da Dor , Dor Intratável/tratamento farmacológico , Dor Intratável/epidemiologia , Dor Intratável/psicologia , Parassimpatolíticos/efeitos adversos , Prevalência , Centros de Reabilitação/estatística & dados numéricos , Estudos Retrospectivos , Autoavaliação (Psicologia) , Índice de Gravidade de Doença , Traumatismos da Medula Espinal/psicologia , Inquéritos e Questionários , Índices de Gravidade do Trauma
15.
Br J Surg ; 94(10): 1232-41, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17665418

RESUMO

BACKGROUND: Genetic mutations and upregulation of growth factors are implicated in the pathogenesis of hyperparathyroidism. The aim of this study was to evaluate the role of Wilms' tumour suppressor gene (WT-1) and the insulin-like growth factor (IGF) axis in hyperparathyroidism. METHODS: The expression of WT-1 and IGF components was examined by immunohistochemistry, reverse transcriptase-polymerase chain reaction and western immunoblotting in a panel of parathyroid specimens from both primary and secondary hyperparathyroidism. A human parathyroid cell culture model was established to examine the parathyroid response to IGF stimulation. RESULTS: There was a significantly lower level of WT-1 expression in parathyroid tumours than in normal parathyroid glands. Most tumours expressed IGF-I and IGF-II receptors and responded to IGF stimulation. Only IGF-I was present in normal parathyroid glands, whereas IGF-II was expressed exclusively in parathyroid tumours. CONCLUSION: Abnormal expression of WT-1 and the IGF axis may play a role in the pathogenesis of hyperparathyroidism.


Assuntos
Hiperparatireoidismo/genética , Somatomedinas/genética , Proteínas WT1/genética , Tumor de Wilms/genética , Células Cultivadas , Feminino , Humanos , Hiperparatireoidismo/metabolismo , Imuno-Histoquímica , Masculino , Mutação/genética , Receptores de Somatomedina/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Somatomedinas/metabolismo , Regulação para Cima , Tumor de Wilms/metabolismo
16.
Br J Pharmacol ; 151(4): 483-93, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17435793

RESUMO

BACKGROUND AND PURPOSE: Some non-steroidal anti-inflammatory drugs (NSAIDs) incidentally induce hypoglycemia, which is often seen in diabetic patients receiving sulphonylureas. NSAIDs influence various ion channel activities, thus they may cause hypoglycemia by affecting ion channel functions in insulin secreting beta cells. This study investigated the effects of the NSAID meclofenamic acid (MFA) on the electrical excitability and the secretion of insulin from pancreatic beta cells. EXPERIMENTAL APPROACH: Using patch clamp techniques and insulin secretion assays, the effects of MFA on the membrane potential and transmembrane current of INS-1 cells, and insulin secretion were studied. KEY RESULTS: Under perforated patch recordings, MFA induced a rapid depolarization in INS-1 cells bathed in low (2.8 mM), but not high (28 mM) glucose solutions. MFA, as well as acetylsalicylic acid (ASA) and flufenamic acid (FFA), excited the cells by inhibiting ATP-sensitive potassium channels (K(ATP)). In whole cell recordings, K(ATP) conductance consistently appeared when intracellular ATP was diluted. Intracellular glibenclamide prevented the development of K(ATP) activity, whereas intracellular MFA had no effect. At low glibenclamide concentrations, MFA induced additional inhibition of the K(ATP) current. Live cell Ca(2+) imaging displayed that MFA elevated intracellular Ca(2+) at low glucose concentrations. Furthermore, MFA dose-dependently increased insulin release under low, but not high, glucose conditions. CONCLUSIONS AND IMPLICATIONS: MFA blocked K(ATP) through an extracellular mechanism and thus increased insulin secretion. As some NSAIDs synergistically inhibit K(ATP) activity together with sulphonylureas, the risk of NSAID-induced hypoglycemia should be considered when glucose-lowering compounds are administered.


Assuntos
Trifosfato de Adenosina/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Células Secretoras de Insulina/efeitos dos fármacos , Insulina/metabolismo , Ácido Meclofenâmico/farmacologia , Bloqueadores dos Canais de Potássio/farmacologia , Animais , Cálcio/metabolismo , Células Cultivadas , Glucose/farmacologia , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/fisiologia , Potenciais da Membrana/efeitos dos fármacos , Camundongos
17.
J Endocrinol ; 190(3): 669-80, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17003268

RESUMO

We investigated whether an increase in cAMP could normalize glucose-stimulated insulin secretion (GSIS) in uncoupling protein-2 (UCP2) overexpressing (ucp2-OE) beta-cells. Indices of beta-cell (beta-TC-6f7 cells and rodent islets) function were measured after induction of ucp2, in the presence or absence of cAMP-stimulating agents, analogs, or inhibitors. Islets of ob/ob mice had improved glucose-responsiveness in the presence of forskolin. Rat islets overexpressing ucp2 had significantly lower GSIS than controls. Acutely, the protein kinase A (PKA) and epac pathway stimulant forskolin normalized insulin secretion in ucp2-OE rat islets and beta-TC-6f7 beta-cells, an effect blocked by specific PKA inhibitors but not mimicked by epac agonists. However, there was no effect of ucp2-OE on cAMP concentrations or PKA activity. In ucp2-OE islets, forskolin inhibited ATP-dependent potassium (K(ATP)) channel currents and (86)Rb(+) efflux, indicative of K(ATP) block. Likewise, forskolin application increased intracellular Ca(2+), which could account for its stimulatory effects on insulin secretion. Chronic exposure to forskolin increased ucp2 mRNA and exaggerated basal secretion but not GSIS. In mice deficient in UCP2, there was no augmentation of either cAMP content or cAMP-dependent insulin secretion. Thus, elevating cellular cAMP can reverse the deficiency in GSIS invoked by ucp2-OE, at least partly through PKA-mediated effects on the K(ATP) channel.


Assuntos
AMP Cíclico/metabolismo , Glucose/farmacologia , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Canais Iônicos/metabolismo , Proteínas Mitocondriais/metabolismo , Transdução de Sinais/fisiologia , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , Linhagem Celular , Colforsina/farmacologia , AMP Cíclico/análise , Proteínas Quinases Dependentes de AMP Cíclico/análise , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Feminino , Glucose/metabolismo , Secreção de Insulina , Canais Iônicos/genética , Masculino , Camundongos , Camundongos Knockout , Proteínas Mitocondriais/genética , Obesidade/metabolismo , Perfusão , Ratos , Ratos Mutantes , Ratos Zucker , Estimulação Química , Proteína Desacopladora 2 , Regulação para Cima
18.
Climacteric ; 9(2): 135-45, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16698660

RESUMO

OBJECTIVES: There is wide variation in the severity of climacteric symptoms and we hypothesized that this could be a reflection of premenopausal hormone levels. METHODS: As part of a long-term cohort study of endocrine risk factors for breast cancer, blood had been collected between 1986 and 1990 from 1882 premenopausal women aged >or=35 years. Questionnaires on menopausal symptom severity were sent to 1,843 surviving women in 2001, of whom 1,434 replied. Estradiol, progesterone and testosterone levels were measured by radioimmunoassay in 680 women who reported a natural menopause and completed the symptom severity section in full. RESULTS: Symptom severity fell with rising premenopausal estradiol levels and women with higher premenopausal testosterone levels had more severe vasomotor symptoms. Over 70% of women with above-median severity of symptoms had used hormone replacement therapy (HRT). Those with higher testosterone levels were less likely to take HRT. CONCLUSIONS: Premenopausal hormone levels may predict risk of severe menopausal symptoms, which in turn influences use of HRT. Paradoxically, a high testosterone level was associated with more vasomotor symptoms but reduced use of HRT. Those at greatest risk of climacteric symptoms may be at lower risk of breast cancer because of premenopausal reduced estrogen exposure.


Assuntos
Estradiol/sangue , Terapia de Reposição de Estrogênios , Menopausa/sangue , Progesterona/sangue , Testosterona/sangue , Adulto , Estudos de Coortes , Feminino , Fogachos/epidemiologia , Fogachos/patologia , Humanos , Estudos Longitudinais , Menopausa/fisiologia , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Índice de Gravidade de Doença
19.
J Hand Surg Br ; 31(4): 436-8, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16690180

RESUMO

Although necessary for bone healing, immobilisation temporarily prevents hand function and may necessitate corrective physiotherapy later. Scaphoid and Colles casts are both commonly used to immobilize scaphoid fractures. Non-union rates are comparable with both casts. The Scaphoid cast incorporates the thumb, whereas the Colles cast leaves the thumb free. We compared the effect of the two casts on hand function in 20 healthy right-hand-dominant volunteers using the Jebsen-Taylor Hand Function Test. Data were obtained through a mixed between and within subject design. Both casts prolonged the time taken to complete the hand function test compared to controls. Testing in the Scaphoid cast took significantly longer than in the Colles cast.


Assuntos
Moldes Cirúrgicos , Fratura de Colles/cirurgia , Mãos/fisiologia , Ligamentos/cirurgia , Osso Escafoide/fisiologia , Osso Escafoide/cirurgia , Adulto , Força da Mão , Humanos , Masculino , Metacarpo , Resultado do Tratamento
20.
J Anim Sci ; 84(4): 834-42, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16543560

RESUMO

The soybean phytoestrogen genistein has a range of estrogenic actions demonstrated in various species; however, only limited research has been done to investigate its effects in swine. The objective of this study was to characterize the effects of a graded dose of genistein on estrogen-sensitive uterine and cervical tissues in ovariectomized gilts. Thirty-four postpubertal gilts were ovariectomized and assigned randomly to 1 of 6 treatment groups 15 d postovariectomy. Treatment groups received vehicle, estradiol benzoate (2 mg/d), or genistein (50, 100, 200, or 400 mg/d) via intramuscular injection at 12-h intervals for 10 d. Following the treatment period, gilts were euthanized, and uterine and cervical tissues were collected and processed for chemical or histological analysis. Uterine and cervical tissue mass, as indicated by wet, dry, and protein weights and total DNA content (expressed per 100 kg of BW), increased as the dosage of genistein increased (P < 0.001 for each regression). Uterine and cervical wet weights were increased by a dosage of 200 mg of genistein/d (P < 0.001 and P < 0.01, respectively) but not by 100 mg of genistein/d (P = 0.38 and P = 0.14, respectively) compared with those of control gilts. Height of epithelial cells lining the uterine glands and the lumen of uterus and cervix increased when gilts were treated with estradiol benzoate or 400 mg of genistein/d (P < 0.01). When the gilts were treated with estradiol benzoate or 400 mg of genistein/d, immunohistochemical staining demonstrated an increase in the percentage of cells that stained positive for progesterone receptor in the uterine glands and in the cells lining the vaginal cervix (P < 0.05). In gilts treated with 400 mg of genistein/d, the percentage of cells stained positive for proliferating cell nuclear antigen increased in the epithelium of the uterine glands, uterine lumen, and vaginal cervix (P < 0.05). Tissue growth was stimulated by genistein in a dosage-dependent manner, although no dosage of genistein induced a response as great as that of estradiol benzoate. Estrogen-sensitive tissues of the ovariectomized gilt, such as the cervix and uterus, are affected by injection of large dosages of the phytoestrogen genistein. The sensitivity of the uterus of the gilt to estrogenic substances makes it a potential model to examine the impact of environmental endocrine modulators on reproductive tissues.


Assuntos
Colo do Útero/efeitos dos fármacos , Estrogênios , Genisteína/farmacologia , Ovariectomia , Suínos/fisiologia , Útero/efeitos dos fármacos , Animais , Colo do Útero/anatomia & histologia , Colo do Útero/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Epitélio/efeitos dos fármacos , Feminino , Genisteína/administração & dosagem , Tamanho do Órgão , Útero/anatomia & histologia , Útero/crescimento & desenvolvimento
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