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1.
BJOG ; 129(5): 796-803, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34800331

RESUMO

OBJECTIVE: To determine the characteristics and outcomes of pregnancy in women with Turner syndrome. DESIGN: Retrospective 20-year cohort study (2000-20). SETTING: Sixteen tertiary referral maternity units in the UK. POPULATION OR SAMPLE: A total of 81 women with Turner syndrome who became pregnant. METHODS: Retrospective chart analysis. MAIN OUTCOME MEASURES: Mode of conception, pregnancy outcomes. RESULTS: We obtained data on 127 pregnancies in 81 women with a Turner phenotype. All non-spontaneous pregnancies (54/127; 42.5%) were by egg donation. Only 9/31 (29%) pregnancies in women with karyotype 45,X were spontaneous, compared with 53/66 (80.3%) pregnancies in women with mosaic karyotype 45,X/46,XX (P < 0.0001). Women with mosaic karyotype 45,X/46,XX were younger at first pregnancy by 5.5-8.5 years compared with other Turner syndrome karyotype groups (P < 0.001), and more likely to have a spontaneous menarche (75.8% versus 50% or less, P = 0.008). There were 17 miscarriages, three terminations of pregnancy, two stillbirths and 105 live births. Two women had aortic dissection (2.5%); both were 45,X karyotype with bicuspid aortic valves and ovum donation pregnancies, one died. Another woman had an aortic root replacement within 6 months of delivery. Ten of 106 (9.4%) births with gestational age data were preterm and 22/96 (22.9%) singleton infants with birthweight/gestational age data weighed less than the tenth centile. The caesarean section rate was 72/107 (67.3%). In only 73/127 (57.4%) pregnancies was there documentation of cardiovascular imaging within the 24 months before conceiving. CONCLUSIONS: Pregnancy in women with Turner syndrome is associated with major maternal cardiovascular risks; these women deserve thorough cardiovascular assessment and counselling before assisted or spontaneous pregnancy managed by a specialist team. TWEETABLE ABSTRACT: Pregnancy in women with Turner syndrome is associated with an increased risk of aortic dissection.


Assuntos
Síndrome de Turner , Cesárea , Estudos de Coortes , Feminino , Humanos , Gravidez , Resultado da Gravidez/epidemiologia , Estudos Retrospectivos , Síndrome de Turner/complicações , Síndrome de Turner/epidemiologia , Síndrome de Turner/genética , Reino Unido/epidemiologia
2.
J AIDS HIV Treat ; 3(1): 4-11, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34263265

RESUMO

BACKGROUND: People with HIV (PWH) are at a disproportionate risk for experiencing both chronic pain and opioid use disorder (OUD). Prescription opioid tapering is typically addressed within the "silo model" of medical care, whereby attention is focused solely on opioid addiction rather than also addressing chronic pain management, and limited communication occurs between patient and providers. OBJECTIVE: This descriptive case study examined an integrative, collaborative care model consisting of Provider, Physical Therapist (PT), and Patient aimed at decreasing chronic pain and opioid use within a multidisciplinary HIV/AIDS clinic. METHOD: A physical-therapy based model of chronic pain mitigation and physician-driven opioid tapering was implemented. The Provider, PT, and Patient worked collaboratively to address physiological pain, pain coping skills and opioid tapering. A patient case example was used to illustrate the implementation of the model for a future, larger study in the same patient population. RESULTS: This model was feasible in this case example in terms of clinic workflow and acceptability to both the Patient and Providers in this clinic. After the intervention, the Patient's pain was fully eliminated, and he had ceased all opioid use. CONCLUSION: Results of this case study suggest that utilizing an integrative, patient-centered approach to both chronic pain management and opioid tapering may be feasible within the context of a multidisciplinary HIV/AIDS clinic. Generalizability is limited by case study model; however, this gives insight into the value of a collaborative alternative compared to a "silo" model of opioid tapering and chronic pain management in preparation for a larger study.

3.
Eur Cell Mater ; 30: 118-30; discussion 130-1, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26388615

RESUMO

Large segmental defects in bone fail to heal and remain a clinical problem. Muscle is highly osteogenic, and preliminary data suggest that autologous muscle tissue expressing bone morphogenetic protein-2 (BMP-2) efficiently heals critical size defects in rats. Translation into possible human clinical trials requires, inter alia, demonstration of efficacy in a large animal, such as the sheep. Scale-up is fraught with numerous biological, anatomical, mechanical and structural variables, which cannot be addressed systematically because of cost and other practical issues. For this reason, we developed a translational model enabling us to isolate the biological question of whether sheep muscle, transduced with adenovirus expressing BMP-2, could heal critical size defects in vivo. Initial experiments in athymic rats noted strong healing in only about one-third of animals because of unexpected immune responses to sheep antigens. For this reason, subsequent experiments were performed with Fischer rats under transient immunosuppression. Such experiments confirmed remarkably rapid and reliable healing of the defects in all rats, with bridging by 2 weeks and remodelling as early as 3-4 weeks, despite BMP-2 production only in nanogram quantities and persisting for only 1-3 weeks. By 8 weeks the healed defects contained well-organised new bone with advanced neo-cortication and abundant marrow. Bone mineral content and mechanical strength were close to normal values. These data demonstrate the utility of this model when adapting this technology for bone healing in sheep, as a prelude to human clinical trials.


Assuntos
Proteína Morfogenética Óssea 2/metabolismo , Regeneração Óssea/genética , Osso e Ossos/lesões , Osso e Ossos/metabolismo , Consolidação da Fratura/genética , Músculo Esquelético/metabolismo , Animais , Animais Geneticamente Modificados , Proteína Morfogenética Óssea 2/genética , Terapia Genética , Vetores Genéticos/uso terapêutico , Masculino , Ratos , Ovinos , Fator de Crescimento Transformador beta/genética
4.
J Biomed Mater Res B Appl Biomater ; 103(6): 1217-1227, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25350377

RESUMO

Soft-tissue regeneration methods currently yield suboptimal clinical outcomes due to loss of tissue volume and a lack of functional tissue regeneration. Grafted tissues and natural biomaterials often degrade or resorb too quickly, while most synthetic materials do not degrade. In previous research we demonstrated that soft-tissue regeneration can be supported using silk porous biomaterials for at least 18 months in vivo in a rodent model. In the present study, we scaled the system to a survival study using a large animal model and demonstrated the feasibility of these biomaterials for soft-tissue regeneration in adult horses. Both slow and rapidly degrading silk matrices were evaluated in subcutaneous pocket and intramuscular defect depots. We showed that we can effectively employ an equine model over 6 months to simultaneously evaluate many different implants, reducing the number of animals needed. Furthermore, we were able to tailor matrix degradation by varying the initial format of the implanted silk. Finally, we demonstrate ultrasound imaging of implants to be an effective means for tracking tissue regeneration and implant degradation.


Assuntos
Implantes Absorvíveis , Modelos Animais de Doenças , Músculo Esquelético/lesões , Músculo Esquelético/fisiologia , Regeneração , Seda/química , Animais , Cavalos , Músculo Esquelético/diagnóstico por imagem , Ultrassonografia
5.
Opt Express ; 22(6): 6919-24, 2014 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-24664040

RESUMO

We describe time-resolved measurements of the evolution of the spectrum of radiation emitted by an optically-pumped continuous-wave InGaAs-GaAs quantum well laser, recorded as lasing builds up from noise to steady state. We extract a fitting parameter corresponding to the gain dispersion of the parabolic spectrum equal to -79 ± 30 fs2 and -36 ± 6 fs2 for a resonant and anti-resonant structure, respectively. Furthermore the recorded evolution of the spectrum allows for the calculation of an effective FWHM gain bandwidth for each structure, of 11 nm and 18 nm, respectively.

6.
Blood ; 123(12): 1917-26, 2014 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-24429338

RESUMO

The molecular mechanisms by which nitric oxide (NO) bioavailability modulates the clinical expression of sickle cell disease (SCD) remain elusive. We investigated the effect of hypoxia and NO bioavailability on sickle red blood cell (sRBC) adhesion using mice deficient for endothelial NO synthase (eNOS) because their NO metabolite levels are similar to those of SCD mice but without hypoxemia. Whereas sRBC adhesion to endothelial cells in eNOS-deficient mice was synergistically upregulated at the onset of hypoxia, leukocyte adhesion was unaffected. Restoring NO metabolite levels to physiological levels markedly reduced sRBC adhesion to levels seen under normoxia. These results indicate that sRBC adherence to endothelial cells increases in response to hypoxia prior to leukocyte adherence, and that low NO bioavailability synergistically upregulates sRBC adhesion under hypoxia. Although multiple adhesion molecules mediate sRBC adhesion, we found a central role for P-selectin in sRBC adhesion. Hypoxia and low NO bioavailability upregulated P-selectin expression in endothelial cells in an additive manner through p38 kinase pathways. These results demonstrate novel cellular and signaling mechanisms that regulate sRBC adhesion under hypoxia and low NO bioavailability. Importantly, these findings point us toward new molecular targets to inhibit cell adhesion in SCD.


Assuntos
Anemia Falciforme/sangue , Eritrócitos Anormais/metabolismo , Hipóxia/sangue , Óxido Nítrico/sangue , Anemia Falciforme/genética , Anemia Falciforme/patologia , Animais , Adesão Celular/fisiologia , Modelos Animais de Doenças , Células Endoteliais/patologia , Células Endoteliais/fisiologia , Eritrócitos Anormais/patologia , Eritrócitos Anormais/fisiologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Mutantes , Óxido Nítrico Sintase Tipo III/sangue , Óxido Nítrico Sintase Tipo III/deficiência , Óxido Nítrico Sintase Tipo III/genética , Selectina-P/metabolismo , Transdução de Sinais , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
7.
Front Immunol ; 4: 480, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24400007

RESUMO

RATIONALE: Diabetic nephropathy (DN) is a major cause of end-stage renal disease, associated with endothelial dysfunction. Chronic supplementation of l-arginine (l-arg), the substrate for endothelial nitric oxide synthase (eNOS), failed to improve vascular function. l-Citrulline (l-cit) supplementation not only increases l-arg synthesis, but also inhibits cytosolic arginase I, a competitor of eNOS for the use of l-arg, in the vasculature. AIMS: To investigate whether l-cit treatment reduces DN in streptozotocin (STZ)-induced type 1 diabetes (T1D) in mice and rats and to study its effects on arginase II (ArgII) function, the main renal isoform. METHODS: STZ-C57BL6 mice received l-cit or vehicle supplemented in the drinking water. For comparative analysis, diabetic ArgII knock out mice and l-cit-treated STZ-rats were evaluated. RESULTS: l-Citrulline exerted protective effects in kidneys of STZ-rats, and markedly reduced urinary albumin excretion, tubulo-interstitial fibrosis, and kidney hypertrophy, observed in untreated diabetic mice. Intriguingly, l-cit treatment was accompanied by a sustained elevation of tubular ArgII at 16 weeks and significantly enhanced plasma levels of the anti-inflammatory cytokine IL-10. Diabetic ArgII knock out mice showed greater blood urea nitrogen levels, hypertrophy, and dilated tubules than diabetic wild type (WT) mice. Despite a marked reduction in collagen deposition in ArgII knock out mice, their albuminuria was not significantly different from diabetic WT animals. l-Cit also restored nitric oxide/reactive oxygen species balance and barrier function in high glucose-treated monolayers of human glomerular endothelial cells. Moreover, l-cit also has the ability to establish an anti-inflammatory profile, characterized by increased IL-10 and reduced IL-1ß and IL-12(p70) generation in the human proximal tubular cells. CONCLUSION: l-Citrulline supplementation established an anti-inflammatory profile and significantly preserved the nephron function during T1D.

8.
Nanoscale ; 4(12): 3693-7, 2012 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-22618689

RESUMO

In this letter we show how a single beam optical trap offers the means for three-dimensional manipulation of semiconductor nanorods in solution. Furthermore rotation of the direction of the electric field provides control over the orientation of the nanorods, which is shown by polarisation analysis of two photon induced fluorescence. Statistics over tens of trapped agglomerates reveal a correlation between the measured degree of polarisation (DLP) and the size of the agglomerate which was determined by the escape frequency and the intensity of the emitted fluorescence. We estimate that we have trapped agglomerates with a volume of close to 10 times the volume of a single nanorod, which exhibited DLPs as high as 52%.

9.
Blood Cells Mol Dis ; 47(4): 235-42, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-21945571

RESUMO

Although reduction in leukocyte counts following hydroxyurea therapy in sickle cell disease (SCD) predicts fetal hemoglobin (HbF) response, the underlying mechanism remains unknown. We previously reported that leukocyte counts are regulated by granulocyte-macrophage colony-stimulating factor (GM-CSF) in SCD patients. Here we examined the roles of GM-CSF in the regulation of HbF expression in SCD. Upon the analysis of retrospective data in 372 patients, HbF levels were inversely correlated with leukocyte counts and GM-CSF levels in SCD patients without hydroxyurea therapy, while HbF increments after hydroxyurea therapy correlated with a reduction in leukocyte counts, suggesting a negative effect of GM-CSF on HbF expression. Consistently, in vitro studies using primary erythroblasts showed that the addition of GM-CSF to erythroid cells decreased HbF expression. We next examined the intracellular signaling pathway through which GM-CSF reduced HbF expression. Treatment of erythroid cells with GM-CSF resulted in the reduction of intracellular cAMP levels and abrogated phosphorylation of cAMP response-element-binding-protein, suggesting attenuation of the cAMP-dependent pathway, while the phosphorylation levels of mitogen-activated protein kinases were not affected. This is compatible with our studies showing a role for the cAMP-dependent pathway in HbF expression. Together, these results demonstrate that GM-CSF plays a role in regulating both leukocyte count and HbF expression in SCD. Reduction in GM-CSF levels upon hydroxyurea therapy may be critical for efficient HbF induction. The results showing the involvement of GM-CSF in HbF expression may suggest possible mechanisms for hydroxyurea resistance in SCD.


Assuntos
Anemia Falciforme/metabolismo , AMP Cíclico/metabolismo , Regulação para Baixo/efeitos dos fármacos , Hemoglobina Fetal/metabolismo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/genética , Linhagem Celular , Células Cultivadas , Células Eritroides/efeitos dos fármacos , Hemoglobina Fetal/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Hidroxiureia/uso terapêutico , Contagem de Leucócitos , RNA Mensageiro/análise , Estudos Retrospectivos , Transcrição Gênica/efeitos dos fármacos
10.
Arch Biochem Biophys ; 510(1): 53-61, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21457702

RESUMO

We previously demonstrated that inhaling nitric oxide (NO) increases the oxygen affinity of sickle red blood cells (RBCs) in patients with sickle cell disease (SCD). Our recent studies found that NO lowered the P(50) values of sickle hemoglobin (HbS) hemolysates but did not increase methemoglobin (metHb) levels, supporting the role of NO, but not metHb, in the oxygen affinity of HbS. Here we examine the mechanism by which NO increases HbS oxygen affinity. Because anti-sickling agents increase sickle RBC oxygen affinity, we first determined whether NO exhibits anti-sickling properties. The viscosity of HbS hemolysates, measured by falling ball assays, increased upon deoxygenation; NO treatment reduced the increment. Multiphoton microscopic analyses showed smaller HbS polymers in deoxygenated sickle RBCs and HbS hemolysates exposed to NO. These results suggest that NO inhibits HbS polymer formation and has anti-sickling properties. Furthermore, we found that HbS treated with NO exhibits an isoelectric point similar to that of HbA, suggesting that NO alters the electric charge of HbS. NO-HbS adducts had the same elution time as HbA upon high performance liquid chromatography analysis. This study demonstrates that NO may disrupt HbS polymers by abolishing the excess positive charge of HbS, resulting in increased oxygen affinity.


Assuntos
Anemia Falciforme/tratamento farmacológico , Antidrepanocíticos/farmacologia , Hemoglobina Falciforme/metabolismo , Óxido Nítrico/farmacologia , Eritrócitos/efeitos dos fármacos , Humanos , Metemoglobina/metabolismo , Oxigênio/metabolismo , Polimerização/efeitos dos fármacos , Viscosidade/efeitos dos fármacos
11.
Blood ; 117(2): 727-35, 2011 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-20926770

RESUMO

Adhesive interactions between circulating sickle red blood cells (RBCs), leukocytes, and endothelial cells are major pathophysiologic events in sickle cell disease (SCD). To develop new therapeutics that efficiently inhibit adhesive interactions, we generated an anti-P-selectin aptamer and examined its effects on cell adhesion using knockout-transgenic SCD model mice. Aptamers, single-stranded oligonucleotides that bind molecular targets with high affinity and specificity, are emerging as new therapeutics for cardiovascular and hematologic disorders. In vitro studies found that the anti-P-selectin aptamer exhibits high specificity to mouse P-selectin but not other selectins. SCD mice were injected with the anti-P-selectin aptamer, and cell adhesion was observed under hypoxia. The anti-P-selectin aptamer inhibited the adhesion of sickle RBCs and leukocytes to endothelial cells by 90% and 80%, respectively. The anti-P-selectin aptamer also increased microvascular flow velocities and reduced the leukocyte rolling flux. SCD mice treated with the anti-P-selectin aptamer demonstrated a reduced mortality rate associated with the experimental procedures compared with control mice. These results demonstrate that anti-P-selectin aptamer efficiently inhibits the adhesion of both sickle RBCs and leukocytes to endothelial cells in SCD model mice, suggesting a critical role for P-selectin in cell adhesion. Anti-P-selectin aptamer may be useful as a novel therapeutic agent for SCD.


Assuntos
Anemia Falciforme/fisiopatologia , Aptâmeros de Nucleotídeos/farmacologia , Adesão Celular/efeitos dos fármacos , Migração e Rolagem de Leucócitos/efeitos dos fármacos , Selectina-P/antagonistas & inibidores , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Técnica de Seleção de Aptâmeros , Ressonância de Plasmônio de Superfície
12.
Pain Med ; 11(11): 1635-53, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21044254

RESUMO

BACKGROUND: Because of disparate taxonomic arrays for classification, the American Academy of Pain Medicine has proposed categorizing pain on a neurobiologic basis as eudynia (nociceptive pain), Greek for "good pain," or maldynia (maladaptive pain), Greek for "bad pain." The latter has been viewed as maladaptive because it may occur in the absence of ongoing noxious stimuli and does not promote healing and repair. OBJECTIVE: To address recent findings on the pathogenesis of pain following neural injury and consider whether the development of maladaptive pain justifies its classification as a disease and to briefly discuss the scope of pharmacologic and non-pharmacologic approaches employed in patients with such pain. METHODS: English language reports on studies using human subjects were selected from a PubMed search of the literature from 1995 to August 2010 and from the Cochrane Library. Further information was obtained from Internet sites of medical specialty and other societies devoted to pain management. RESULTS: Neural damage to either the peripheral or central nervous system provokes multiple processes including peripheral and central sensitization, ectopic activity, neuronal cell death, disinhibition, altered gene expression, and abnormal sprouting and cellular connectivity. A series of neuro-immune interactions underlie many of these mechanisms. Imaging studies have shown that such damage is characterized by functional, structural, and chemical changes in the brain. Such pain is maladaptive in the sense that it occurs in the absence of ongoing noxious stimuli and does not promote healing and repair. CONCLUSION: As defined, maldynia is a multidimensional process that may warrant consideration as a chronic disease not only affecting sensory and emotional processing but also producing an altered brain state based on both functional imaging and macroscopic measurements. However, the absolute clinical value of this definition is not established.


Assuntos
Neuralgia/fisiopatologia , Dor/etiologia , Dor/fisiopatologia , American Medical Association , Humanos , Neuralgia/terapia , Manejo da Dor , Estados Unidos
13.
Am J Hematol ; 85(10): 800-2, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20799359

RESUMO

Pain from vaso-occlusive crisis (VOC) is the major cause of hospitalization in patients with sickle cell disease (SCD). The beneficial therapeutic effects of inhaled nitric oxide (NO) on the pathophysiology of SCD have been reported. A double-blind, randomized, placebo-controlled clinical trial was conducted to determine whether NO breathing reduces acute VOC pain in adult patients and to study the safety of inhaled NO. Twenty-three patients experiencing acute VOC were enrolled. After randomization but before treatment, five were found to not meet final eligibility criteria. Nine patients were assigned to inhaled NO (80 ppm) and nine to placebo (21% O2). Primary outcome was the mean change in pain scores after 4 hr of inhalation, measured on a 10-cm visual analog scale (VAS). Both groups had similar baseline VAS pain scores but inhaled NO significantly reduced pain scores compared with placebo (P 5 0.02) at the end of NO inhalation. Secondary outcome was parenteral morphine use at baseline, 4, and 6 hr. Parenteral morphine use was lower in the inhaled NO group, but the difference was not statistically significant.Safety assessments included systolic blood pressure measurements,pulse oximetry readings, concentration of delivered nitrogen dioxide, and concentration of methemoglobin (metHb). None of these NO toxicities was observed.


Assuntos
Anemia Falciforme/complicações , Óxido Nítrico/uso terapêutico , Dor/tratamento farmacológico , Doença Aguda , Administração por Inalação , Adulto , Anemia Falciforme/fisiopatologia , Moléculas de Adesão Celular/biossíntese , Terapia Combinada , Método Duplo-Cego , Feminino , Humanos , Masculino , Morfina/administração & dosagem , Morfina/uso terapêutico , Entorpecentes/administração & dosagem , Entorpecentes/uso terapêutico , Óxido Nítrico/administração & dosagem , Óxido Nítrico/efeitos adversos , Oxigenoterapia , Dor/fisiopatologia , Medição da Dor , Adulto Jovem
14.
Eur Arch Otorhinolaryngol ; 267(2): 273-9, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19536555

RESUMO

The objective of the present study is to characterize genitourinary tumors (GU) metastatic to the head and neck and to determine long-term prognoses. Using a retrospective chart review of 734 patients treated between January 1995 and May 2005 with an ICD-9 code pertaining to a metastatic head and neck cancer, we found 37 patients with primary GU tumors. There were 24 cases of prostate cancer, 10 cases of renal cell carcinoma, and 4 cases of transitional cell carcinoma. Sixteen of 24 patients (67%) with prostate cancer had a cranial metastasis while 6 of 9 (67%) patients with renal cell carcinoma had cerebral metastasis. We concluded that prolonged survival is possible in prostate cancer patients treated aggressively with radiation and chemotherapy, indicating that early detection and aggressive screening are important in these patients.


Assuntos
Carcinoma de Células Renais/secundário , Carcinoma de Células de Transição/secundário , Neoplasias de Cabeça e Pescoço/secundário , Neoplasias da Próstata/patologia , Neoplasias da Bexiga Urinária/patologia , Idoso , Idoso de 80 Anos ou mais , California/epidemiologia , Carcinoma de Células Renais/diagnóstico , Carcinoma de Células de Transição/diagnóstico , Feminino , Seguimentos , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Fatores de Tempo , Neoplasias Urogenitais/patologia
15.
Eur Cell Mater ; 18: 96-111, 2009 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-20073015

RESUMO

We report a novel technology for the rapid healing of large osseous and chondral defects, based upon the genetic modification of autologous skeletal muscle and fat grafts. These tissues were selected because they not only possess mesenchymal progenitor cells and scaffolding properties, but also can be biopsied, genetically modified and returned to the patient in a single operative session. First generation adenovirus vector carrying cDNA encoding human bone morphogenetic protein-2 (Ad.BMP-2) was used for gene transfer to biopsies of muscle and fat. To assess bone healing, the genetically modified ("gene activated") tissues were implanted into 5mm-long critical size, mid-diaphyseal, stabilized defects in the femora of Fischer rats. Unlike control defects, those receiving gene-activated muscle underwent rapid healing, with evidence of radiologic bridging as early as 10 days after implantation and restoration of full mechanical strength by 8 weeks. Histologic analysis suggests that the grafts rapidly differentiated into cartilage, followed by efficient endochondral ossification. Fluorescence in situ hybridization detection of Y-chromosomes following the transfer of male donor muscle into female rats demonstrated that at least some of the osteoblasts of the healed bone were derived from donor muscle. Gene activated fat also healed critical sized defects, but less quickly than muscle and with more variability. Anti-adenovirus antibodies were not detected. Pilot studies in a rabbit osteochondral defect model demonstrated the promise of this technology for healing cartilage defects. Further development of these methods should provide ways to heal bone and cartilage more expeditiously, and at lower cost, than is presently possible.


Assuntos
Tecido Adiposo/transplante , Doenças Ósseas/terapia , Doenças das Cartilagens/terapia , Técnicas de Transferência de Genes , Músculo Esquelético/transplante , Transplante de Tecidos/métodos , Tecido Adiposo/citologia , Tecido Adiposo/metabolismo , Animais , Proteína Morfogenética Óssea 2/genética , Regeneração Óssea/fisiologia , Diferenciação Celular/fisiologia , Linhagem Celular , Linhagem da Célula/fisiologia , Modelos Animais de Doenças , Feminino , Fêmur/citologia , Fêmur/metabolismo , Fêmur/cirurgia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Terapia Genética/métodos , Vetores Genéticos/genética , Sobrevivência de Enxerto/fisiologia , Humanos , Masculino , Músculo Esquelético/citologia , Músculo Esquelético/metabolismo , Coelhos , Ratos , Ratos Endogâmicos F344 , Transplante Autólogo/métodos , Resultado do Tratamento , Cicatrização/fisiologia
16.
Bone ; 41(2): 247-55, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17553763

RESUMO

Clinical drawbacks of bone grafting prompt the search for alternative bone augmentation technologies such as use of growth and differentiation factors, gene therapy, and cell therapy. Osteopromotive matrices are frequently employed for the local delivery and controlled release of these augmentation agents. Some matrices also provide an osteoconductive scaffold to support new bone growth. In this study, silkworm-derived silk fibroin was evaluated as an osteoconductive matrix for healing critical sized mid-femoral segmental defects in nude rats. Four treatment groups were assessed over eight weeks: silk scaffolds (SS) with recombinant human BMP-2 (rhBMP-2) and human mesenchymal stem cells (HMSC) that had been pre-differentiated along an osteoblastic lineage ex vivo (Group I; pdHMSC/rhBMP-2/SS); SS with rhBMP-2 and undifferentiated HMSCs (Group II; udHMSC/rhBMP-2/SS); SS and rhBMP-2 alone (Group III; rhBMP-2/SS); and empty defects (Group IV). Bi-weekly radiographs revealed a progressive and similar increase in Group I-III mean defect mineralization through post-operative week (POW) 8. Radiographs, dual energy x-ray absorptiometry, and micro-computed tomography confirmed that Groups I-III exhibited similar substantial and significantly (p<0.05) greater defect mineralization at POW 8 than the unfilled Group IV defects which remained void of bone. No significant differences in Groups I-III defect healing at POW 8 were apparent using these same assays or mechanical testing. Histology at POW 8 revealed moderately good bridging of the parent diaphyseal cortices with woven and lamellar bone bridging islands of silk matrix in Groups I and III. Group II defects possessed comparatively less new bone which was most abundant adjacent to the parent bone margins. Elsewhere the silk matrix was more often enveloped by poorly differentiated loose fibrous connective tissue. Group IV defects showed minimal new bone formation. None of the treatment groups attained the mean mineralization or the mean biomechanical strength of identical defects implanted with SS and pdHMSCs alone in a previous study. However, addition of rhBMP-2 to SS prompted more bone than was previously generated using udHMSC/SS or SS alone. These data imply the clinical potential of silk scaffolds and rhBMP-2 as composite osteopromotive implants when used alone or with select stem cell populations. Additional studies in larger species are now warranted.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Regeneração Óssea/fisiologia , Transplante Ósseo , Fêmur/patologia , Seda/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Absorciometria de Fóton , Animais , Bombyx , Proteína Morfogenética Óssea 2 , Proteínas Morfogenéticas Ósseas/genética , Fêmur/diagnóstico por imagem , Fêmur/cirurgia , Humanos , Implantes Experimentais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Osteogênese/fisiologia , Ratos , Ratos Nus , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Estresse Mecânico , Tomografia Computadorizada por Raios X , Fator de Crescimento Transformador beta/genética
17.
J Dent Res ; 85(12): 1061-73, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17122156

RESUMO

Mounting effective anti-tumor immune responses against tumors by both the innate and adaptive immune effectors is important for the clearance of tumors. However, accumulated evidence indicates that immune responses that should otherwise suppress or eliminate transformed cells are themselves suppressed by the function of tumor cells in a variety of cancer patients, including those with oral cancers. Signaling abnormalities, spontaneous apoptosis, and reduced proliferation and function of circulating natural killer cells (NK), T-cells, dendritic cells (DC), and tumor-infiltrating lymphocytes (TILs) have been documented previously in oral cancer patients. Several mechanisms have been proposed for the functional deficiencies of tumor-associated immune cells in oral cancer patients. Both soluble factors and contact-mediated immunosuppression by the tumor cells have been implicated in the inhibition of immune cell function and the progression of tumors. More recently, elevated levels and function of key transcription factors in tumor cells, particularly NFkappaB and STAT3, have been shown to mediate immune suppression in the tumor microenvironment. This review will focus on these emerging mechanisms of immunosuppression in oral cancers.


Assuntos
Tolerância Imunológica/imunologia , Neoplasias Bucais/imunologia , Apoptose/imunologia , Células Dendríticas/imunologia , Humanos , Imunidade Celular/imunologia , Células Matadoras Naturais/imunologia , Linfócitos do Interstício Tumoral/imunologia , NF-kappa B/imunologia , Fator de Transcrição STAT3/imunologia , Transdução de Sinais/imunologia
19.
Bone ; 39(4): 922-31, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16757219

RESUMO

Bone auto- and allografts have inherent drawbacks, therefore the treatment of non-unions and critical size defects in load bearing long bones would benefit from the use of osteopromotive biodegradable, biocompatible and mechanically durable matrices to enhance migration or delivery of cell populations and/or morphogens/cytokines. Silk fibroin biomaterial scaffolds were evaluated as osteopromotive matrices in critical sized mid-femoral segmental defects in nude rats. Four treatment groups were assessed over 8 weeks in vivo: silk scaffolds (SS) with human mesenchymal stem cells (hMSCs) that had previously been differentiated along an osteoblastic lineage in vitro (group I; pdHMSC/SS); SS with undifferentiated hMSCs (group II; udHMSC/SS); SS alone (group III; SS); and empty defects (group IV). When hMSCs were cultured in vitro in osteogenic medium for 5 weeks, bone formation was characterized with bimodal peak activities for alkaline phosphatase at 2 and 4 weeks. Calcium deposition started after 1 week and progressively increased to peak at 4 weeks, reaching cumulative levels of deposited calcium at 16 mug per mg scaffold wet weight. In vivo osteogenesis was characterized by almost bridged defects with newly formed bone after 8 weeks in group I. Significantly (P < 0.01) greater bone volumes were observed with the pdHMSC/SS (group I) implants than with groups II, III or IV. These three groups failed to induce substantial new bone formation and resulted in the ingrowth of cells with fibroblast-like morphology into the defect zone. The implantation of pdHMSC/SS resulted in significantly (P < 0.05) greater maximal load and torque when compared to the other treatment regimens. The pdHMSC/SS implants demonstrated osteogenic ability in vitro and capacity to thrive towards the healing of critical size femoral segmental defects in vivo. Thus, these new constructs provide an alternative protein-based biomaterial for load bearing applications.


Assuntos
Materiais Biocompatíveis/uso terapêutico , Fêmur/efeitos dos fármacos , Seda/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Materiais Biocompatíveis/metabolismo , Cálcio/metabolismo , Células Cultivadas , Fêmur/patologia , Fêmur/cirurgia , Fibroínas/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Distribuição Aleatória , Ratos , Ratos Nus , Fatores de Tempo , Engenharia Tecidual/métodos , Tomografia Computadorizada por Raios X/métodos , Transplante Heterólogo , Resultado do Tratamento
20.
Heart ; 91(8): 1070-4, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16020599

RESUMO

OBJECTIVE: To report the timing of presentation and clinical profile of a cohort of fetuses with normal main cardiac connections but fetal echocardiographic signs suggestive of coarctation of the aorta. DESIGN: Retrospective observational study. SETTING: Tertiary fetal and paediatric cardiology centre. PATIENTS: Between 1 January 1998 and 31 December 2002, 174 fetuses were studied, of whom 144 infants were born alive. MAIN OUTCOME MEASURES: Of the 144 liveborn infants, 43 had coarctation of the aorta, four had interruption of the aortic arch, and one was managed as having hypoplastic left heart syndrome. Hemianomalous pulmonary venous drainage was diagnosed in two infants. Three infants with coarctation presented late at 7-13 weeks of age, 6-12 weeks after closure of the arterial duct. Fetuses with cardiac asymmetry had a higher incidence of left superior vena cava than a control group. For fetuses with cardiac asymmetry, the incidence of left superior vena cava and ventricular septal defects was similar in infants who proved to have coarctation postnatally and in those who did not. The 30 day and one year surgical mortality of infants having repair of coarctation of the aorta was two of 41 (4.9%, 95% confidence interval (CI) 0.6 to 16.0). All cause mortality of liveborn infants with any abnormality of the aortic arch was five of 48 (10.4%, 95% CI 3.5 to 22.7) at 30 days and one year, which was heavily influenced by prematurity and extracardiac abnormalities. CONCLUSIONS: Precise diagnosis of coarctation of the aorta during fetal life remains difficult. Coarctation of the aorta may present several weeks after closure of the arterial duct and sequential echocardiography is recommended.


Assuntos
Coartação Aórtica/diagnóstico por imagem , Ecocardiografia/métodos , Doenças Fetais/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Coartação Aórtica/embriologia , Coartação Aórtica/patologia , Feminino , Doenças Fetais/patologia , Humanos , Lactente , Gravidez , Resultado da Gravidez , Estudos Retrospectivos , Fatores de Tempo
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