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1.
Sci Rep ; 13(1): 16919, 2023 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-37805649

RESUMO

Type 2 diabetes (T2D) and its complications can have debilitating, sometimes fatal consequences for afflicted individuals. The disease can be difficult to control, and therapeutic strategies to prevent T2D-induced tissue and organ damage are needed. Here we describe the results of administering a potent and selective inhibitor of Protein Kinase C (PKC) family members PKCα and PKCß, Cmpd 1, in the ZSF1 obese rat model of hyperphagia-induced, obesity-driven T2D. Although our initial intent was to evaluate the effect of PKCα/ß inhibition on renal damage in this model setting, Cmpd 1 unexpectedly caused a marked reduction in the hyperphagic response of ZSF1 obese animals. This halted renal function decline but did so indirectly and indistinguishably from a pair feeding comparator group. However, above and beyond this food intake effect, Cmpd 1 lowered overall animal body weights, reduced liver vacuolation, and reduced inguinal adipose tissue (iWAT) mass, inflammation, and adipocyte size. Taken together, Cmpd 1 had strong effects on multiple disease parameters in this obesity-driven rodent model of T2D. Further evaluation for potential translation of PKCα/ß inhibition to T2D and obesity in humans is warranted.


Assuntos
Adiposidade , Diabetes Mellitus Tipo 2 , Humanos , Ratos , Animais , Adiposidade/fisiologia , Proteína Quinase C-alfa , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Obesidade/complicações , Obesidade/tratamento farmacológico , Hiperfagia/complicações , Hiperfagia/tratamento farmacológico , Rim/fisiologia
2.
Epileptic Disord ; 25(1): 87-93, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37032541

RESUMO

Sturge-Weber Syndrome (SWS) is a rare neurocutaneous disorder caused by focal vascular dysplasia. It is associated with facial angiomas, ocular abnormalities, epilepsy, intellectual disability, and leptomeningeal angiomas. There is a paucity of literature regarding the management of epilepsy and pregnancy in women with SWS. The effects of pregnancy on this syndrome therefore remain largely undefined. Consensus on management is needed; as pregnancy has widespread effects on the vascular system and therefore may pose risk in women with SWS. This is a comprehensive review of the existing literature and case report of a woman with SWS, refractory epilepsy, and a successful pregnancy and delivery. Fifteen cases were found and, in addition to our case, 14 cases were reviewed, 11 of which discuss labor and delivery. Neurological complications were described in four cases and successful delivery without complication occurred in seven patient cases.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsia , Deficiência Intelectual , Síndrome de Sturge-Weber , Humanos , Feminino , Gravidez , Síndrome de Sturge-Weber/complicações , Epilepsia Resistente a Medicamentos/complicações , Epilepsia/complicações , Face , Deficiência Intelectual/complicações
3.
Hum Gene Ther ; 33(3-4): 175-187, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34931542

RESUMO

Recombinant adeno-associated viruses (AAVs) have emerged as promising vectors for human gene therapy, but some variants have induced severe toxicity in Rhesus monkeys and piglets following high-dose intravenous (IV) administration. To characterize biodistribution, transduction, and toxicity among common preclinical species, an AAV9 neurotropic variant expressing the survival motor neuron 1 (SMN1) transgene (AAV-PHP.B-CBh-SMN1) was administered by IV bolus injection to Wistar Han rats and cynomolgus monkeys at doses of 2 × 1013, 5 × 1013, or 1 × 1014 vg/kg. A dose-dependent degeneration/necrosis of neurons without clinical manifestations occurred in dorsal root ganglia (DRGs) and sympathetic thoracic ganglia in rats, while liver injury was not observed in rats. In monkeys, one male at 5 × 1013 vg/kg was found dead on day 4. Clinical pathology data on days 3 and/or 4 at all doses suggested liver dysfunction and coagulation disorders, which led to study termination. Histologic evaluation of the liver in monkeys showed hepatocyte degeneration and necrosis without inflammatory cell infiltrates or intravascular thrombi, suggesting that hepatocyte injury is a direct effect of the vector following hepatocyte transduction. In situ hybridization demonstrated a dose-dependent expression of SMN1 transgene mRNA in the cytoplasm and DNA in the nucleus of periportal to panlobular hepatocytes, while quantitative polymerase chain reaction confirmed the dose-dependent presence of SMN1 transgene mRNA and DNA in monkeys. Monkeys produced a much greater amount of transgene mRNA compared with rats. In DRGs, neuronal degeneration/necrosis and accompanying findings were observed in monkeys as early as 4 days after test article administration. The present results show sensory neuron toxicity following IV delivery of AAV vectors at high doses with an early onset in Macaca fascicularis and after 1 month in rats, and suggest adding the autonomic system in the watch list for preclinical and clinical studies. Our data also suggest that the rat may be useful for evaluating the potential DRG toxicity of AAV vectors, while acute hepatic toxicity associated with coagulation disorders appears to be highly species-dependent.


Assuntos
Dependovirus , Vetores Genéticos , Animais , Dependovirus/genética , Vetores Genéticos/genética , Macaca fascicularis , Masculino , Neurônios Motores , Necrose , RNA Mensageiro , Ratos , Ratos Wistar , Suínos , Distribuição Tecidual , Transdução Genética
4.
Lancet Respir Med ; 9(5): 457-466, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33524320

RESUMO

BACKGROUND: Bronchial thermoplasty is an endoscopic treatment for uncontrolled asthma. Previous randomised clinical trials have shown that bronchial thermoplasty reduces severe exacerbations in people with asthma. However, the long-term efficacy and safety of bronchial thermoplasty beyond 5 years is unknown. The BT10+ study aimed to investigate the efficacy and safety of bronchial thermoplasty after 10 or more years of follow-up. METHODS: BT10+ was an international, multicentre, follow-up study of participants who were previously enrolled in the AIR, RISA, and AIR2 trials and who had 10 or more years of follow-up since bronchial thermoplasty treatment. Data on patient demographics, quality of life, lung function, CT scans (AIR2 participants only), severe exacerbations, and health-care use during the previous year were collected at the BT10+ 10-year outcomes study visit. The primary effectiveness endpoint was durability of the thermoplasty treatment effect, determined by comparing the proportion of participants who had severe exacerbations during the first and fifth years after bronchial thermoplasty treatment with the proportion of participants who had severe exacerbations during the 12-month period before the BT10+ visit. The primary safety endpoint was the absence of clinically significant post-treatment respiratory image changes after bronchial thermoplasty, defined as bronchiectasis or bronchial stenosis as confirmed by pulmonary volumetric high-resolution CT scan at the BT10+ visit (AIR2 participants only). All analyses were done on an intention-to-treat basis. The trial is registered with ClinicalTrials.gov, NCT03243292. The last patient was enrolled on Dec 11, 2018. The last patient completed follow-up on Jan 10, 2019. FINDINGS: The BT10+ study enrolled 192 (45%) of the 429 participants who were enrolled in the AIR, RISA, and AIR2 trials. The BT10+ participants comprised 136 who received bronchial thermoplasty (52% of the 260 participants who received bronchial thermoplasty in the original trials), and 56 sham or control participants (33% of 169 from the original trials). 18 (32%) sham or control participants received bronchial thermoplasty after the previous trials concluded. The participants included in BT10+ were followed for 10·8-15·6 years (median 12·1 years) post-treatment. Baseline characteristics were similar between participants enrolled in BT10+ and those not enrolled. Participants treated with bronchial thermoplasty had similar proportions of severe exacerbations at the BT10+ visit (34 [25%] of 136 participants) compared with 1 year (33 [24%] of 135 participants; difference 0·6%, 95% CI -9·7 to 10·8) and 5 years (28 [22%] of 130 participants; difference 3·5%, -6·7% to 13·6) after treatment. Quality of life measurements and spirometry were similar between year 1, year 5, and the BT10+ visit. At the BT10+ study visit, pulmonary high-resolution CT scans from AIR2 participants treated with bronchial thermoplasty showed that 13 (13%) of 97 participants had bronchiectasis. When compared with baseline high-resolution CT scans, six (7%) of 89 participants treated with bronchial thermoplasty who did not have bronchiectasis at baseline had developed bronchiectasis after treatment (5 classified as mild, 1 classified as moderate). Participants treated with bronchial thermoplasty after the original study and participants in the sham or control group also had reductions in severe exacerbations at the BT10+ visit compared with baseline. INTERPRETATION: Our findings suggest that efficacy of bronchial thermoplasty is sustained for 10 years or more, with an acceptable safety profile. Therefore, bronchial thermoplasty is a long-acting therapeutic option for patients with asthma that remains uncontrolled despite optimised medical treatment. FUNDING: Boston Scientific.


Assuntos
Asma , Termoplastia Brônquica , Pulmão , Qualidade de Vida , Asma/fisiopatologia , Asma/psicologia , Asma/terapia , Termoplastia Brônquica/efeitos adversos , Termoplastia Brônquica/métodos , Broncoscopia/métodos , Demografia/estatística & dados numéricos , Progressão da Doença , Feminino , Seguimentos , Humanos , Pulmão/diagnóstico por imagem , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Testes de Função Respiratória/métodos , Exacerbação dos Sintomas , Tempo , Resultado do Tratamento
5.
Expert Opin Pharmacother ; 19(17): 1927-1940, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30325679

RESUMO

INTRODUCTION: Pancreatic adenocarcinoma is the 9th most common cancer in the United States and the 4th most common cause of cancer-related death given its poor prognosis. AREAS COVERED: The authors have performed a literature search for pertinent published clinical trials, ongoing Phase 3 clinical trials, and current treatment guidelines using PubMed, Clinicaltrials.gov, and NCCN, ASCO, ESMO, and JPS websites. The review itself discusses landmark studies and ongoing research into the chemotherapy regimens recommended by each oncologic society. The authors also examine drugs that were promising but failed in Phase 3 trials and those currently being investigated. Finally, the authors provide their expert opinion on the subject and provide their future perspectives. EXPERT OPINION: While advances in chemotherapy for pancreatic cancer have been limited in comparison to other cancers, there have been improvements in survival. Combination therapy and a goal of R0 resection are key elements to extend life. Novel agents directed at the unique properties of pancreatic cancer are promising.


Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Pancreáticas/tratamento farmacológico , Animais , Humanos
6.
Ann Surg Oncol ; 25(13): 3804-3811, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30218244

RESUMO

BACKGROUND: Outcomes for pancreatic resection have been studied extensively due to the high morbidity and mortality rates, with high-volume centers achieving superior outcomes. Ongoing investigations include healthcare costs, given the national focus on reducing expenditures. Therefore, we sought to evaluate the relationships between pancreatic surgery costs with perioperative outcomes and volume status. METHODS: We performed a retrospective analysis of 27,653 patients who underwent elective pancreatic resections from October 2013 to June 2017 using the Vizient database. Costs were calculated from charges using cost-charge ratios and adjusted for geographic variation. Generalized linear modeling adjusting for demographic, clinical, and operation characteristics was performed to assess the relationships between cost and length of stay, complications, in-hospital mortality, readmissions, and hospital volume. High-volume centers were defined as hospitals performing ≥ 19 operations annually. RESULTS: The unadjusted mean cost for pancreatic resection and corresponding hospitalization was $20,352. There were no differences in mean costs for pancreatectomies performed at high- and low-volume centers [- $1175, 95% confidence interval (CI) - $3254 to $904, p = 0.27]. In subgroup analysis comparing adjusted mean costs at high- and low-volume centers, there was no difference among patients without an adverse outcome (- $99, 95% CI - $1612 to 1414, p = 0.90), one or more adverse outcomes (- $1586, 95% CI - $4771 to 1599, p = 0.33), or one or more complications (- $2835, 95% CI - $7588 to 1919, p = 0.24). CONCLUSIONS: While high-volume hospitals have fewer adverse outcomes, there is no relationship between surgical volume and costs, which suggests that, in itself, surgical volume is not an indicator of improved healthcare efficiency reflected by lower costs. Patient referral to high-volume centers may not reduce overall healthcare expenditures for pancreatic operations.


Assuntos
Custos de Cuidados de Saúde/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Hospitais com Alto Volume de Atendimentos/estatística & dados numéricos , Hospitais com Baixo Volume de Atendimentos/economia , Pancreatectomia/economia , Neoplasias Pancreáticas/economia , Feminino , Seguimentos , Hospitais com Baixo Volume de Atendimentos/estatística & dados numéricos , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Morbidade , Neoplasias Pancreáticas/cirurgia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
7.
BMC Public Health ; 18(1): 914, 2018 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-30045702

RESUMO

BACKGROUND: In the United States, problematic stimulant use is a prevalent and difficult to treat problem among men who have sex with men (MSM), as well as a major driver of HIV transmission through the large number of sexual partners and concomitant condomless anal sex (CAS). Evidence-based behavioral studies that address problematic stimulant use in MSM at risk for HIV infection are also lacking. In this paper, we describe the design of a behavioral intervention trial to reduce sexual risk behavior and stimulant use in HIV-uninfected MSM. METHODS: This study, funded by the National Institute on Drug Abuse (NIDA), is a randomized controlled trial (RCT) testing an integrated HIV risk reduction and behavioral activation counseling intervention (IMPACT) for HIV-uninfected, stimulant using MSM in Boston, MA, and Miami, FL. Participants are randomized (2:2:1) to either (1) the IMPACT intervention; (2) a relaxation condition, an active therapy time- and intensity-matched control; or (3) a standard of care risk reduction counseling comparison. At enrollment, all participants receive an HIV test and pre- and post-test counseling. The primary outcome is the difference in the rate of change in the number of self-reported condomless anal sex acts without the protection of consistent Pre-Exposure Prophylaxis (PrEP) use, as well as reductions in stimulant use during the prior 4-months. Major assessments are conducted at baseline, 4-, 8-, and 12-month follow-up visits. DISCUSSION: Effective and sustainable behavioral interventions are sorely needed to reduce HIV acquisition in stimulant using MSM at risk for HIV infection. In this study, we will evaluate the evidence of efficacy of the IMPACT intervention to reduce HIV acquisition in HIV-uninfected, stimulant-using MSM. If found effective, the intervention tested here holds promise for being readily integrated into real-world clinical settings. TRIAL REGISTRATION: ClinicalTrials.gov number NCT03175159 , registered June 5, 2017.


Assuntos
Terapia Comportamental/estatística & dados numéricos , Infecções por HIV/prevenção & controle , Aconselhamento Sexual/estatística & dados numéricos , Minorias Sexuais e de Gênero/psicologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adulto , Terapia Comportamental/métodos , Boston , Estimulantes do Sistema Nervoso Central , Florida , HIV , Infecções por HIV/psicologia , Homossexualidade Masculina/psicologia , Humanos , Masculino , Profilaxia Pré-Exposição/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto , Comportamento de Redução do Risco , Assunção de Riscos , Sexo Seguro/psicologia , Aconselhamento Sexual/métodos , Comportamento Sexual/psicologia , Parceiros Sexuais/psicologia , Transtornos Relacionados ao Uso de Substâncias/virologia , Resultado do Tratamento
8.
J Virol Methods ; 247: 81-90, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28583856

RESUMO

Rose rosette disease, caused by Rose rosette virus (RRV; genus Emaravirus) is a major threat to the rose industry in the U.S. The only strategy currently available for disease management is early detection and eradication of the infected plants, thereby limiting its potential spread. Current RT-PCR based diagnostic methods for RRV are time consuming and are inconsistent in detecting the virus from symptomatic plants. Real-time RT-qPCR assay is highly sensitive for detection of RRV, but it is expensive and requires well-equipped laboratories. Both the RT-PCR and RT-qPCR cannot be used in a field-based testing for RRV. Hence a novel probe based, isothermal reverse transcription-recombinase polymerase amplification (RT-exoRPA) assay, using primer/probe designed based on the nucleocapsid gene of the RRV has been developed. The assay is highly specific and did not give a positive reaction to other viruses infecting roses belonging to both inclusive and exclusive genus. Dilution assays using the in vitro transcript showed that the primer/probe set is highly sensitive, with a detection limit of 1 fg/µl. In addition, a rapid technique for the extraction of viral RNA (<5min) has been standardized from RRV infected tissue sources, using PBS-T buffer (pH 7.4), which facilitates the virus adsorption onto the PCR tubes at 4°C for 2min, followed by denaturation to release the RNA. RT-exoRPA analysis of the infected plants using the primer/probe indicated that the virus could be detected from leaves, stems, petals, pollen, primary roots and secondary roots. In addition, the assay was efficiently used in the diagnosis of RRV from different rose varieties, collected from different states in the U.S. The entire process, including the extraction can be completed in 25min, with less sophisticated equipments. The developed assay can be used with high efficiency in large scale field testing for rapid detection of RRV in commercial nurseries and landscapes.


Assuntos
Técnicas de Amplificação de Ácido Nucleico/métodos , Doenças das Plantas/virologia , Vírus de Plantas/isolamento & purificação , Vírus de RNA/isolamento & purificação , RNA Viral/análise , Rosa/virologia , Primers do DNA/genética , Nepovirus , Nucleocapsídeo/genética , Sondas de Oligonucleotídeos/genética , Vírus de Plantas/genética , Vírus de RNA/genética , RNA Viral/genética , Sensibilidade e Especificidade , Temperatura , Fatores de Tempo , Estados Unidos
9.
J Am Vet Med Assoc ; 243(10): 1455-61, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24171376

RESUMO

OBJECTIVE: To determine whether a diagnosis of chronic small bowel disease could be established in a subset of cats that had clinical signs of chronic vomiting, chronic small bowel diarrhea, weight loss, or a combination of these, combined with ultrasonographically determined thickening of the small bowel. DESIGN: Retrospective case series. ANIMALS: 100 client-owned domestic cats. PROCEDURES: Medical records of cats with clinical signs of chronic vomiting, chronic small bowel diarrhea, weight loss, or a combination of these, combined with ultrasonographically determined small bowel thickening, that underwent laparotomy and multiple small bowel biopsies between 2008 and 2012 were examined. Biopsy specimens were submitted for histologic evaluation, immunohistochemical evaluation, and, when findings were ambiguous, PCR assay for antigen receptor rearrangement. RESULTS: Chronic small bowel disease was diagnosed in 99 of the 100 cats. The most common diagnoses were chronic enteritis and intestinal lymphoma. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that cats with clinical signs of chronic small bowel disease should undergo detailed diagnostic testing because they are likely to have clinically important, diagnosable, treatable disease. Clinical signs of small bowel disease, especially weight loss and chronic or recurrent vomiting, are extremely common in cats. These signs should not be considered a normal condition and should not be ignored, regardless of common explanations given by owners, and cats with these signs should undergo appropriate diagnostic testing.


Assuntos
Doenças do Gato/diagnóstico , Enteropatias/veterinária , Intestino Delgado/patologia , Animais , Doenças do Gato/patologia , Gatos , Doença Crônica , Feminino , Enteropatias/diagnóstico , Enteropatias/patologia , Masculino , Estudos Retrospectivos
10.
Tissue Eng Part A ; 18(17-18): 1912-20, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22559300

RESUMO

Tissue-engineered muscle has been proposed as a solution to repair volumetric muscle defects and to restore muscle function. To achieve functional recovery, engineered muscle tissue requires integration of the host nerve. In this study, we investigated whether denervated muscle, which is analogous to tissue-engineered muscle tissue, can be reinnervated and can recover muscle function using an in vivo model of denervation followed by neurotization. The outcomes of this investigation may provide insights on the ability of tissue-engineered muscle to integrate with the host nerve and acquire normal muscle function. Eighty Lewis rats were classified into three groups: a normal control group (n=16); a denervated group in which sciatic innervations to the gastrocnemius muscle were disrupted (n=32); and a transplantation group in which the denervated gastrocnemius was repaired with a common peroneal nerve graft into the muscle (n=32). Neurofunctional behavior, including extensor postural thrust (EPT), withdrawal reflex latency (WRL), and compound muscle action potential (CMAP), as well as histological evaluations using alpha-bungarotoxin and anti-NF-200 were performed at 2, 4, 8, and 12 weeks (n=8) after surgery. We found that EPT was improved by transplantation of the nerve grafts, but the EPT values in the transplanted animals at 12 weeks postsurgery were still significantly lower than those measured for the normal control group at 4 weeks (EPT, 155.0±38.9 vs. 26.3±13.8 g, p<0.001; WRL, 2.7±2.30 vs. 8.3±5.5 s, p=0.027). In addition, CMAP latency and amplitude significantly improved with time after surgery in the transplantation group (p<0.001, one-way analysis of variance), and at 12 weeks postsurgery, CMAP latency and amplitude were not statistically different from normal control values (latency, 0.9±0.0 vs. 1.3±0.7 ms, p=0.164; amplitude, 30.2±7.0 vs. 46.4±26.9 mV, p=0.184). Histologically, regeneration of neuromuscular junctions was seen in the transplantation group. This study indicates that transplanted nerve tissue is able to regenerate neuromuscular junctions within denervated muscle, and thus the muscle can recover partial function. However, the function of the denervated muscle remains in the subnormal range even at 12 weeks after direct nerve transplantation. These results suggest that tissue-engineered muscle, which is similarly denervated, could be innervated and become functional in vivo if it is properly integrated with the host nerve.


Assuntos
Músculos/inervação , Músculos/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Engenharia Tecidual/métodos , Animais , Articulação do Tornozelo/patologia , Articulação do Tornozelo/fisiopatologia , Comportamento Animal , Fenômenos Eletrofisiológicos , Masculino , Denervação Muscular , Músculos/patologia , Músculos/cirurgia , Proteínas de Neurofilamentos/metabolismo , Ratos , Ratos Endogâmicos Lew , Receptores Colinérgicos/metabolismo
11.
Int Neurourol J ; 15(3): 109-19, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22087419

RESUMO

Neurogenic bladder is a general term encompassing various neurologic dysfunctions of the bladder and the external urethral sphincter. These can be caused by damage or disease. Therapeutic management options can be conservative, minimally invasive, or surgical. The current standard for surgical management is bladder augmentation using intestinal segments. However, because intestinal tissue possesses different functional characteristics than bladder tissue, numerous complications can ensue, including excess mucus production, urinary stone formation, and malignancy. As a result, investigators have sought after alternative solutions. Tissue engineering is a scientific field that uses combinations of cells and biomaterials to encourage regeneration of new, healthy tissue and offers an alternative approach for the replacement of lost or deficient organs, including the bladder. Promising results using tissue-engineered bladder have already been obtained in children with neurogenic bladder caused by myelomeningocele. Human clinical trials, governed by the Food and Drug Administration, are ongoing in the United States in both children and adults to further evaluate the safety and efficacy of this technology. This review will introduce the principles of tissue engineering and discuss how it can be used to treat refractory cases of neurogenic bladder.

12.
Chonnam Med J ; 47(1): 1-13, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22111050

RESUMO

Novel therapies resulting from regenerative medicine and tissue engineering technology may offer new hope for patients with injuries, end-stage organ failure, or other clinical issues. Currently, patients with diseased and injured organs are often treated with transplanted organs. However, there is a shortage of donor organs that is worsening yearly as the population ages and as the number of new cases of organ failure increases. Scientists in the field of regenerative medicine and tissue engineering are now applying the principles of cell transplantation, material science, and bioengineering to construct biological substitutes that can restore and maintain normal function in diseased and injured tissues. In addition, the stem cell field is a rapidly advancing part of regenerative medicine, and new discoveries in this field create new options for this type of therapy. For example, new types of stem cells, such as amniotic fluid and placental stem cells that can circumvent the ethical issues associated with embryonic stem cells, have been discovered. The process of therapeutic cloning and the creation of induced pluripotent cells provide still other potential sources of stem cells for cell-based tissue engineering applications. Although stem cells are still in the research phase, some therapies arising from tissue engineering endeavors that make use of autologous, adult cells have already entered the clinical setting, indicating that regenerative medicine holds much promise for the future.

13.
Radiat Res ; 162(1): 1-19, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15222781

RESUMO

Tissue damage caused by exposure to pathogens, chemicals and physical agents such as ionizing radiation triggers production of generic "danger" signals that mobilize the innate and acquired immune system to deal with the intrusion and effect tissue repair with the goal of maintaining the integrity of the tissue and the body. Ionizing radiation appears to do the same, but less is known about the role of "danger" signals in tissue responses to this agent. This review deals with the nature of putative "danger" signals that may be generated by exposure to ionizing radiation and their significance. There are a number of potential consequences of "danger" signaling in response to radiation exposure. "Danger" signals could mediate the pathogenesis of, or recovery from, radiation damage. They could alter intrinsic cellular radiosensitivity or initiate radioadaptive responses to subsequent exposure. They may spread outside the locally damaged site and mediate bystander or "out-of-field" radiation effects. Finally, an important aspect of classical "danger" signals is that they link initial nonspecific immune responses in a pathological site to the development of specific adaptive immunity. Interestingly, in the case of radiation, there is little evidence that "danger" signals efficiently translate radiation-induced tumor cell death into the generation of tumor-specific immunity or normal tissue damage into autoimmunity. The suggestion is that radiation-induced "danger" signals may be inadequate in this respect or that radiation interferes with the generation of specific immunity. There are many issues that need to be resolved regarding "danger" signaling after exposure to ionizing radiation. Evidence of their importance is, in some areas, scant, but the issues are worthy of consideration, if for no other reason than that manipulation of these pathways has the potential to improve the therapeutic benefit of radiation therapy. This article focuses on how normal tissues and tumors sense and respond to danger from ionizing radiation, on the nature of the signals that are sent, and on the impact on the eventual consequences of exposure.


Assuntos
Lesões por Radiação/etiologia , Animais , Apoptose/efeitos da radiação , Relação Dose-Resposta à Radiação , Humanos , Imunidade/efeitos da radiação , Neoplasias/imunologia , Tolerância a Radiação , Radioterapia
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