RESUMO
This study examined the effect of curcumin on pathological manifestations and clearance of amyloid ß peptide (Aß) in the hippocampus of 8-month-old transgenic APP/PS1 mice with inherent Alzheimer's disease. APP/PS1 mice and the age-matched wild-type controls were subjected to 3 behavioral tests: open field, new object recognition, and Morris water maze. Expression of Aß, APP, CTF, BACE1, IDE, NEP, and LRP1 proteins in the extracted hippocampal tissue was evaluated by Western blotting. The distribution and the quantity of amyloid plaques and the spread of microglia in the hippocampus were determined by immunofluorescence. The contents of Aß40 and Aß42 in the hippocampus were assayed and analyzed on Simoa HD-1 analyzer. The proteins interacting with Aß in the hippocampus of APP/PS1 mice were detected by co-immunoprecipitation. Curcumin significantly reduced motor hyperactivity in the open-field test, improved short-term recognition memory, spatial learning, and reference memory in APP/PS1 mice. In the hippocampus of APP/PS1 mice, curcumin significantly diminished the elevated Aß levels and inhibited microglia proliferation. At the same time, curcumin had no effect on Aß production, extracellular enzymatic hydrolysis, and LRP1-mediated outward transport, but enhanced Aß clearance by activation of the intracellular ubiquitin-proteasome system and related peripheral mechanisms. Thus, curcumin improves the learning and memory abilities of APP/PS1 mice and reduces the pathological accumulation of Aß in the brain.
Assuntos
Doença de Alzheimer , Cognição , Hipocampo , Curcumina/farmacologia , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Comportamento Animal , Hipocampo/efeitos dos fármacos , Masculino , Animais , Camundongos , Camundongos TransgênicosRESUMO
BACKGROUND: The therapeutic value of repeat hepatic resection (rHR) or radiofrequency ablation (RFA) for recurrent hepatocellular carcinoma (HCC) is unknown. This study aimed to investigate the safety and efficacy of rHR or RFA. METHODS: This was a retrospective multicentre study of patients with recurrent HCC within the Milan criteria who underwent rHR or RFA at nine university hospitals in China and Italy between January 2003 and January 2018. Survival after rHR or RFA was examined in unadjusted analyses and after propensity score matching (1 : 1). RESULTS: Of 847 patients included, 307 and 540 underwent rHR and RFA respectively. Median overall survival was 73.5 and 67.0 months after rHR and RFA respectively (hazard ratio 1.01 (95 per cent c.i. 0.81 to 1.26)). Median recurrence-free survival was longer after rHR versus RFA (23.6 versus 15.2 months; hazard ratio 0.76 (95 per cent c.i. 0.65 to 0.89)). These results were confirmed after propensity score matching. RFA was associated with lower morbidity of grade 3 and above (0.6 versus 6.2 per cent; P < 0.001) and shorter hospital stay (8.0 versus 3.0 days, P < 0.001) than rHR. CONCLUSION: rHR was associated with longer recurrence-free survival but not overall survival compared with RFA.
Assuntos
Carcinoma Hepatocelular/cirurgia , Hepatectomia , Neoplasias Hepáticas/cirurgia , Recidiva Local de Neoplasia/cirurgia , Ablação por Radiofrequência , Intervalo Livre de Doença , Feminino , Hepatectomia/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Ablação por Radiofrequência/efeitos adversos , Estudos Retrospectivos , Análise de Sobrevida , Resultado do TratamentoRESUMO
There is no consensus about factors that increase risk of hepatocellular carcinoma (HCC) among patients with chronic hepatitis B who have achieved seroclearance of hepatitis B surface antigen (HBsAg). To assess the available evidence about risk factors for HCC after HBsAg seroclearance, Scopus, EMBASE, PubMed and Cochrane Library databases were systematically searched for relevant studies published through 15 September 2017. A total of 28 studies involving more than 105 411 patients with chronic hepatitis B were included. HBsAg seroclearance occurred spontaneously in 7656, while it occurred after interferon or nucleos(t)ide analogue therapy in 1248. The rate of HBsAg seroclearance was 6.77%. Incidence of HCC was significantly lower among patients who experienced HBsAg seroclearance than among those who remained HBsAg-positive (1.86% vs 6.56%, P < .001). Risk factors of HCC occurrence included cirrhosis (incidence with vs without: 9.51% vs 1.66%), male gender (2.34% vs 0.64%) and age ≥ 50 year at HBsAg seroclearance (2.34% vs 0.63%) (all P < .001). The available evidence suggests that HCC can develop at a low rate after HBsAg seroclearance, so periodic surveillance is recommended, especially for male patients, patients with cirrhosis and patients who experience HBsAg seroclearance when at least 50 years old.
Assuntos
Carcinoma Hepatocelular/epidemiologia , Antígenos de Superfície da Hepatite B/sangue , Hepatite B Crônica/complicações , Soroconversão , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antivirais/uso terapêutico , Feminino , Hepatite B Crônica/tratamento farmacológico , Humanos , Incidência , Cirrose Hepática/complicações , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores SexuaisRESUMO
BACKGROUND: The Child-Pugh (CP) score is used widely to assess liver function and predict postoperative outcomes in patients with hepatocellular carcinoma (HCC). Recently, the albumin-bilirubin (ALBI) score has been validated as a predictor of overall survival in these patients. This study aimed to compare the ability of the ALBI and CP scores to predict outcomes in patients with HCC after liver resection with curative intent. METHODS: Consecutive patients who underwent liver resection with curative intent for HCC between January 2007 and July 2013 were included in this retrospective study. The performance of the ALBI score in predicting postoperative liver failure (PHLF) and long-term survival was compared with that of the CP score. RESULTS: A total of 1242 patients were enrolled. Of these, 166 (13·4 per cent) experienced PHLF. The area under the receiver operating characteristic (ROC) curve of the ALBI score for predicting PHLF was greater than that of the CP score (0·723 versus 0·607; P < 0·001). Similar to findings for CP grade, the incidence and severity of PHLF increased with increasing ALBI grade. The ALBI grade stratified patients into at least two distinct overall survival cohorts (P < 0·001), whereas the CP grade did not. The ALBI grade also classified patients with CP grade A disease into two distinct overall survival cohorts (P < 0·001), and overall survival rates in the group with poorer survival were similar to those in the majority of patients with CP grade B disease. Both CP and ALBI scores had low power in predicting disease-free survival. CONCLUSION: The ALBI grade predicted PHLF and overall survival in patients with HCC undergoing liver resection with curative intent more accurately than the CP grade.
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Bilirrubina/sangue , Carcinoma Hepatocelular/cirurgia , Hepatectomia/métodos , Falência Hepática/diagnóstico , Neoplasias Hepáticas/cirurgia , Albumina Sérica/análise , Adulto , Idoso , Carcinoma Hepatocelular/mortalidade , Feminino , Hepatectomia/mortalidade , Humanos , Falência Hepática/etiologia , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde/métodos , Prognóstico , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
In Alzheimer's disease (AD), neurodegenerative signals such as amyloid-beta (Aß) and the precursors of neurotrophins, outbalance neurotrophic signals, causing synaptic dysfunction and neurodegeneration. The neurotrophin receptor p75 (p75NTR) is a receptor of Aß and mediates Aß-induced neurodegenerative signals. The shedding of its ectodomain from the cell surface is physiologically regulated; however, the function of the diffusible p75NTR ectodomain (p75ECD) after shedding remains largely not known. Here, we show that p75ECD levels in cerebrospinal fluid and in the brains of Alzheimer's patients and amyloid-beta precursor protein (APP)/PS1 transgenic mice were significantly reduced, due to inhibition of the sheddase-tumor necrosis factor-alpha-converting enzyme by Aß. Restoration of p75ECD to the normal level by brain delivery of the gene encoding human p75ECD before or after Aß deposition in the brain of APP/PS1 mice reversed the behavioral deficits and AD-type pathologies, such as Aß deposit, apoptotic events, neuroinflammation, Tau phosphorylation and loss of dendritic spine, neuronal structures and synaptic proteins. Furthermore, p75ECD can also reduce amyloidogenesis by suppressing ß-secretase expression and activities. Our data demonstrate that p75ECD is a physiologically neuroprotective molecule against Aß toxicity and would be a novel therapeutic target and biomarker for AD.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Encéfalo/patologia , Proteínas do Tecido Nervoso/química , Estrutura Terciária de Proteína/fisiologia , Receptores de Fator de Crescimento Neural/química , Proteínas ADAM/metabolismo , Proteína ADAM17 , Fatores Etários , Doença de Alzheimer/complicações , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/toxicidade , Precursor de Proteína beta-Amiloide/genética , Animais , Apoptose/fisiologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Estudos de Casos e Controles , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/terapia , Modelos Animais de Doenças , Regulação para Baixo/genética , Humanos , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Transgênicos , Mutação/genética , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Presenilina-1/genética , Receptores de Fator de Crescimento Neural/deficiência , Receptores de Fator de Crescimento Neural/genética , Proteínas Recombinantes/uso terapêutico , Transdução GenéticaRESUMO
Objective: To compare the efficacy of hepatic resection (HR) in patients with Barcelona Clinical Liver Cancer (BCLC) Stage B hepatocellular carcinoma (HCC) and examine how that efficacy has changed over time in a large medical center. Methods: A consecutive sample of 918 patients with preserved liver function and large and/or multinodular HCC who were treated by initial HR were divided into three groups: those with a single tumor ≥5 cm in diameter (n=582), 2-3 tumors with a maximum diameter>3 cm (n=223), or>3 tumors of any diameter (n=113). Hospital mortality and overall survival (OS) in each group were compared for the years 2001-2007 and 2008-2013. Results: Patients with >3 tumors showed the highest incidence of hospital mortality of all groups (P<0.05). Kaplan-Meier survival analysis showed that OS varied across the three groups as follows: single tumor>2-3 tumors >3+ tumors (all P<0.05). OS rate at 5 years ranged from 24% to 41% in all three groups for the period 2001-2007, and from 35% to 46% for the period 2008-2013. OS was significantly higher during the more recent 6-year period in the entire patient population, those with single tumor, and those with 3+ tumors (all P<0.05). However, in patients with 2-3 tumors, OS was only slightly higher during the more recent 6-year period (P=0.084). Conclusions: Prognosis of three types of HCC was different. Patients with >3 tumors show the highest hospital mortality and lowest OS after HR. OS has been improving for all three types of HCC at our medical center as a consequence of improvements in surgical technique and perioperative management.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Mortalidade Hospitalar , Humanos , Estimativa de Kaplan-Meier , Prognóstico , Taxa de SobrevidaRESUMO
OBJECTIVE: To investigate the influence of the PI3K/AKT signaling pathway on the proportion and characteristics of the stem-like CD90(+) subpopulation of the human hepatocellular carcinoma (HCC) cell line MHCC-97. METHODS: MHCC-97H cultures were treated with the PI3K/AKT pathway inhibitor LY294002. The proportion of the CD90(+) subpopulation was determined by flow cytometry, and the expression of related proteins was measured by Western blot. The clonogenicity of CD90(+) and CD90(-) cells was measured by plate colony formation assay. The tumorigenicity was compared between CD90(+) and CD90(-) subpopulations (with different concentrations) in xenograft experiments in nude mice, and the changes in tumorigenicity after the addition of LY294002 were evaluated. The changes in the expression of CD90, SHP2, P-AKT, and AKT in CD90(+) and CD90(-) cell xenografts after the addition of LY294002 were examined. Data were analyzed using t test. RESULTS: LY294002 was capable of reducing the proportion of CD90(+) HCC stem cells from 2.98%±0.08% to 0.78%±0.08% (t = 32.400, P < 0.01) and reducing the clonogenicity of CD90(+) subpopulation from 95.13%±3.78% to 61.82%±7.23% (t = 7.617, P < 0.01). However, it showed no significant effect on the clonogenicity of CD90(-) subpopulation. LY294002 also reduced the tumorigenicity of CD90(+) subpopulation and the expression of CD90, SHP2, and P-AKT in related HCC stem cells, but it did not significantly affect the expression of AKT. LY294002 had no significant inhibitory effect on the tumorigenicity of CD90(-) cells. CONCLUSION: The CD90(+) subpopulation of MHCC-97H cells has the characteristics of stem cells and is dependent on the PI3K/AKT signaling pathway.
Assuntos
Carcinoma Hepatocelular/metabolismo , Células-Tronco Neoplásicas/citologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Antígenos Thy-1/metabolismo , Animais , Linhagem Celular Tumoral , Cromonas , Humanos , Neoplasias Hepáticas/metabolismo , Camundongos , Camundongos Nus , Morfolinas , Transplante de NeoplasiasRESUMO
Carcinogenesis of breast carcinoma is very complicated. Previous studies have suggested conflicting results regarding the association between Tyr113His and His139Arg microsomal epoxide hydrolase (mEH) gene polymorphisms and risk of breast carcinoma. We conducted a meta-analysis to examine the relationship between these polymorphisms and breast carcinoma risk. We searched the PubMed, EMBASE, and Google Scholar databases to identify relevant studies. After extracting relevant data, the association between mEH polymorphisms and susceptibility to breast carcinoma was examined by meta-analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the strength of the association. Seven studies were identified that included 6357 cases and 8090 controls. The mEH His-allele was not associated with the risk of breast carcinoma based on the allelic contrast model (OR = 0.99, 95%CI = 0.94-1.04, P = 0.58), dominant genetic model (OR = 1.14, 95%CI = 0.88-1.48, P = 0.33), or recessive genetic model (OR = 1.03, 95%CI = 0.96-1.10, P = 0.43). Similarly, the mEH Arg-allele was not associated with breast carcinoma risk based on the allelic contrast model (OR = 0.97, 95%CI = 0.91-1.04, P = 0.44), dominant genetic model (OR = 1.01, 95%CI = 0.84-1.21, P = 0.94), or recessive genetic model (OR = 1.04, 95%CI = 0.96-1.12, P = 0.35). Subgroup analysis based on ethnicity showed no association between the polymorphisms and risk of breast carcinoma. Thus, the Tyr113His and His139Arg mEH polymorphisms may not be risk factors for breast carcinoma.
Assuntos
Neoplasias da Mama/genética , Epóxido Hidrolases/genética , Polimorfismo Genético , Alelos , Etnicidade , Feminino , Humanos , Razão de Chances , Fatores de RiscoRESUMO
Coptotermes Wasmann is one of the most important genera of wood-destroying insect pests, both in its native and introduced countries. Pyrethroids are among the most widely used insecticides in wood preservation around the world. Consequently, they have often been evaluated against different species of Coptotermes. However, because various test methods have been used between countries, comparing results is problematic. These field trials, using a single aboveground method of exposure, assessed a range of retentions of two pyrethroids (bifenthrin and permethrin) in Pinus radiata D. Don sapwood against two species of Coptotermes in three countries to provide directly comparable results. Coptotermes acinaciformis (Froggatt) in Australia consumed the most nontreated wood, followed by Coptotermes formosanus Shiraki in China, then C. formosanus in the United States, although these data were not significantly different. Both termite species demonstrated a dose-response to wood treated with the two pyrethroids; less wood was consumed as retention increased. Overall, C. acinaciformis consumed relatively little of the treated wood. In comparison, C. formosanus consumed 20-90% of the wood treated at the lowest retentions of the pyrethroids evaluated. Results indicated that C. acinaciformis was more sensitive to pyrethroid toxicity/repellency compared with C. formosanus. Factors that may have influenced the results are discussed. However, using a single aboveground method of exposure across three countries, that suited both species of Coptotermes, made it possible to determine unambiguously the actual differences between the species in their tolerances to the two pyrethroid insecticides.
Assuntos
Inseticidas , Isópteros , Piretrinas , Madeira/química , Animais , InternacionalidadeRESUMO
The high risk of recurrence in post-operative hepatocellular carcinoma (HCC) highlights the need for an effective adjuvant treatment. A systematic review of randomised controlled trials (RCTs) was performed to evaluate the clinical efficacy of adjuvant adoptive immunotherapy (AIT) for post-operative HCC patients. Electronic (MEDLINE, EMBASE and Cochrane Library databases) and manual searches were conducted throughout May 2011 to identify RCTs evaluating postoperative AIT for patients with HCC. Methodological quality was assessed in accordance with the QUOROM statement. Four RCTs totalling 423 patients met the eligibility criteria. All RCTs reported significantly improved disease-free survival rate or reduced recurrence rate after treating with adjuvant AIT (p < 0.05). The overall survival rates of AIT group are slightly higher than those of the control group in one study. Moreover, AIT was a safe treatment, with fever as the main adverse effects. This study adds to the evidence that postoperative HCC patients treated with adjuvant AIT show an improvement in disease-free survival rate or recurrence rate.
Assuntos
Carcinoma Hepatocelular/terapia , Imunoterapia Adotiva/métodos , Neoplasias Hepáticas/terapia , Adjuvantes Imunológicos/uso terapêutico , Carcinoma Hepatocelular/cirurgia , Intervalo Livre de Doença , Humanos , Imunoterapia Adotiva/efeitos adversos , Neoplasias Hepáticas/cirurgia , Recidiva Local de Neoplasia/prevenção & controle , Cuidados Pós-Operatórios/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do TratamentoRESUMO
OBJECTIVE: To determine expressions of MicroRNA-19a-3p (miRNA-19a-3p) and PDCD5 in nasopharyngeal carcinoma (NPC) tissues, and their prognostic potentials in NPC. PATIENTS AND METHODS: Expressions of miRNA-19a-3p and PDCD5 in NPC tissues and controls were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The correlation between expressions of miRNA-19a-3p and PDCD5 in NPC was evaluated by Pearson correlation test. Furthermore, potential influences of miRNA-19a-3p and PDCD5 on clinical features of NPC patients were assessed. Through 5-year follow-up, survival analysis in NPC patients was conducted by Kaplan-Meier method. Finally, factors influencing prognosis of NPC were determined using the Cox regression model. RESULTS: MiRNA-19a-3p was upregulated and PDCD5 was downregulated in NPC tissues. Pearson correlation test uncovered a negative correlation between expression levels of miRNA-19a-3p and PDCD5 in NPC tissues. MiRNA-19a-3p level was correlated with N classification and clinical stage in NPC patients, while PDCD5 level was correlated with T classification, pathological grade and clinical stage. Survival analysis showed poor prognosis in NPC patients expressing high level of miRNA-19a-3p or low level of PDCD5. Cox regression analysis illustrated that N2+3 classification, clinical stage III+IV, high level of miRNA-19a-3p and low level of PDCD5 were independent risk factors for the prognosis of NPC. CONCLUSIONS: MiRNA-19a-3p is upregulated and PDCD5 is downregulated in NPC tissues. High level of miRNA-19a-3p and low level of PDCD5 are unfavorable for the prognosis of NPC.
Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , MicroRNAs/metabolismo , Carcinoma Nasofaríngeo/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Reguladoras de Apoptose/genética , Feminino , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/diagnóstico , Neoplasias Nasofaríngeas/diagnóstico , Proteínas de Neoplasias/genética , PrognósticoRESUMO
BACKGROUND: Transarterial embolisation (TAE) is a standard treatment for bleeding hepatocellular adenoma (HCA) and, occasionally, symptomatic HCA involving large tumours. Whether TAE is similarly safe and effective as an elective treatment for bleeding and nonbleeding HCA remains unclear. AIM: To investigate the benefits and harms of TAE for bleeding and nonbleeding HCA. METHODS: PubMed, Scopus, Embase and Cochrane Library databases were systematically searched for studies that examined post-TAE tumour reduction in patients with bleeding or nonbleeding HCA and that were published between January 2000 and January 2017. RESULTS: Systematic review of 21 case series involving 1468 patients with HCA in the systematic review identified 140 (9.5%) patients with 189 lesions who received TAE. Of these 140 patients, 66.4% had bleeding HCA and 33.6% had nonbleeding HCA. Intended elective TAE was performed in 27.1% of patients (38.6% of HCA lesions). Adenomatosis was observed in 6.1% of patients, and the rate of ß-catenin expression was 4.5%. No malignant transformation was observed among the 189 tumours during a median follow-up time of 40 months. The complete response rate among 70 patients was 10.6%, and the partial response rate was 71.7%. No mortality or severe adverse side effects were reported during the hospitalisation period. CONCLUSIONS: The available evidence suggests that TAE can be considered safe for elective managment of HCA as well as for management of bleeding HCA. Elective TAE can be regarded as a reasonable alternative to surgery. High-quality prospective studies with long-term follow-up are needed to corroborate and strengthen available evidence.
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OBJECTIVE: This study reviewed the distribution of each tumor stage and each type of initial treatment modality among patients with primary hepatocellular carcinoma (HCC) treated at a tertiary tumor hospital between January 2003 and October 2013. METHODS: Baseline data of patients with primary hepatocellular carcinoma treated between January 2003 and October 2013 were retrospectively collected. Tumor stage was determined according to the Barcelona Clinic Liver Cancer (BCLC) staging system and Hong Kong Clinic Liver Cancer (HKLC) staging system. RESULTS: A total of 6241 patients with primary hepatocellular carcinoma were included in the analysis. In accordance with the BCLC, 28.9% of patients were in stage 0/A, 16.2% in stage B, 53.6% in stage C, and 1.3% in stage D. According to the HKLC stage system, 8.4% patients were in stage I, 1.5% in stage IIa, 29.0% in stage IIb, 10.0% in stage IIIa, 33.6% in stage IIIb, 3.4% in stage IVa, 2.5% in stage IVb, 0.2% in stage Va, and 11.4% in stage Vb. Treatment modalities applied to this patient group were as follows: 33.3% of patients underwent hepatic resection, 36.7% underwent transarterial chemoembolization (TACE), 2.2% underwent radiotherapy, 0.9% underwent local ablated therapy, 8.8% underwent systemic chemotherapy, 4.2% underwent traditional herbal medicine therapy, 0.1% underwent targeted drug therapy, and 13.8% received no treatment. Hepatic resection was the most frequent therapy for patients with BCLC 0/A/B disease, and TACE was the initial therapy for patients with BCLC C disease. In the Hong Kong Clinic Liver Cancer staging system, the main treatments for HKLC I to IIIb disease is hepatic resection and TACE. Systemic chemotherapy was the initial therapy for patients with HKLC IVa/IVb disease. Most HKLC Va/Vb patients received traditional Chinese medicine treatment. CONCLUSION: Prevalence of stage BCLC B and C disease was high among our hepatocellular carcinoma patients. In Hong Kong Clinic Liver Cancer staging system, HKLC I to IIIb disease was high among our HCC patients. Hepatic resection and TACE are initial therapies.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Hepatocelular/patologia , Quimioembolização Terapêutica , Hepatectomia , Neoplasias Hepáticas/patologia , Carcinoma Hepatocelular/terapia , Terapia Combinada , Feminino , Seguimentos , Humanos , Neoplasias Hepáticas/terapia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
After peripheral nerve injury, axotomized sensory neurons in dorsal root ganglia (DRG) undergo apoptosis and up-regulate brain-derived neurotrophic factor (BDNF). We tested whether endogenous BDNF plays any role in the survival of axotomized sensory neurons using in vitro and in vivo models. In the in vitro model, treatment with BDNF antibody significantly reduced apoptosis of sensory neurons in DRG explants from both adult and neonate rats and adult mice cultured for 48 h. Consistently, exogenous BDNF increased the percentage of apoptotic neurons in the DRGs from mice. The effects of the BDNF antibody and BDNF were not seen in DRGs from p75NTR(-/-) mice. In the in vivo model, sciatic nerve transection in neonatal rats decreased the total number of neurons in the injured DRG and treatment with antiserum to BDNF significantly exaggerated the loss of DRG neurons. Numbers of sensory neurons expressing BDNF and p75NTR in cultured DRGs increased but that expressing TrkB decreased. In contrast, sciatic nerve transection in vivo reduced the numbers of neurons expressing both p75NTR and TrkB but increased the numbers of cells expressing BDNF, 1 and 7 days after the surgery. These results suggest that BDNF may have differential effects on the survival of sensory neurons depending on the expression of p75NTR. While endogenous BDNF induced apoptosis of axotomized sensory neurons through p75NTR in vitro where more neurons expressed p75NTR, it prevented apoptosis in vivo where fewer neurons expressed p75NTR after sciatic nerve transection.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/fisiologia , Gânglios Espinais/citologia , Neurônios Aferentes/fisiologia , Receptores de Fator de Crescimento Neural/fisiologia , Animais , Animais Recém-Nascidos , Anticorpos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Axotomia/métodos , Western Blotting/métodos , Fator Neurotrófico Derivado do Encéfalo/imunologia , Contagem de Células/métodos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Ensaio de Imunoadsorção Enzimática/métodos , Lateralidade Funcional , Gânglios Espinais/crescimento & desenvolvimento , Imuno-Histoquímica/métodos , Marcação In Situ das Extremidades Cortadas/métodos , Indóis , Camundongos , Camundongos Knockout , Neurônios Aferentes/efeitos dos fármacos , Técnicas de Cultura de Órgãos , Ratos , Receptor de Fator de Crescimento Neural , Receptor trkB/metabolismo , Receptores de Fator de Crescimento Neural/deficiência , Fatores de TempoRESUMO
Peripheral nerve injury results in plastic changes in the dorsal root ganglia and spinal cord, and is often complicated with neuropathic pain. The mechanisms underlying these changes are not known. We have now investigated the expression of brain-derived neurotrophic factor in the dorsal root ganglia with histochemical and biochemical methods following sciatic nerve lesion in the rat. The percentage of neurons immunoreactive for brain-derived neurotrophic factor in the ipsilateral dorsal root ganglia was significantly increased as early as 24 h after the nerve lesion and the increase lasted for at least two weeks. The level of brain-derived neurotrophic factor messenger RNA was also significantly increased in the ipsibut not contralateral dorsal root ganglia. Both neurons and satellite cells in the lesioned dorsal root ganglia synthesized brain-derived neurotrophic factor messenger RNA after the nerve lesion. There was a dramatic shift in size distribution of positive neurons towards large sizes seven days after sciatic nerve lesion. Morphometric analysis and retrograde tracing studies showed that no injured neurons smaller than 600 microm2 were immunoreactive for brain-derived neurotrophic factor, whereas the majority of large injured neurons were immunoreactive in the ipsilateral dorsal root ganglia seven days postlesion. The brain-derived neurotrophic factor-immunoreactive nerve terminals in the ipsilateral spinal cord were reduced in the central region of lamina II, but increased in more medial regions or deeper into laminae III/IV. These studies indicate that sciatic nerve injury results in a differential regulation of brain-derived neurotrophic factor in different subpopulations of sensory neurons in the dorsal root ganglia. Small neurons switched off their normal synthesis of brain-derived neurotrophic factor, whereas larger ones switched to a brain-derived neurotrophic factor phenotype. The phenotypic switch may have functional implications in neuronal plasticity and generation of neuropathic pain after nerve injury.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Neurônios Aferentes/metabolismo , Nervo Isquiático/lesões , Ferimentos e Lesões/metabolismo , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Contagem de Células , Tamanho Celular , Feminino , Gânglios Espinais/metabolismo , Gânglios Espinais/patologia , Masculino , Neurônios Aferentes/patologia , Neurônios Aferentes/fisiologia , Fenótipo , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/patologia , Nervo Isquiático/fisiologia , Medula Espinal/metabolismo , Ferimentos e Lesões/genéticaRESUMO
Peripheral nerve injury results in sympathetic sprouting around large diameter sensory neurons in the dorsal root ganglia (DRG). The mechanism underlying this pathological phenomenon is not known. Brain-derived neurotrophic factor (BDNF) is up-regulated in large sensory neurons and ensheathing satellite cells following a sciatic nerve injury. In the present study, we investigated the effects of BDNF on the sympathetic sprouting in the DRG, by delivering BDNF antibody or antisense oligodeoxynucleotide to injured DRGs, or by delivering exogenous BDNF to intact DRGs. The sheep antibody to BDNF, characterized by bioassays and dot blots, specifically reacted with BDNF but not other neurotrophins. Noradrenergic fibers were visualized by immunostaining of tyrosine hydroxylase (TH) and quantified by an NIH Imaging program. Two weeks following L5 spinal nerve lesion, a dramatic increase in TH-immunoreactive (-ir) fibres was observed in both ipsi- and contralateral DRGs in normal sheep IgG treated rats. BDNF antibody significantly reduced the sprouting of sympathetic nerves in both ipsi- and contra-lateral DRGs by 67% and 42% respectively. BDNF antisense oligodeoxynucleotide, by inhibiting BDNF synthesis in DRGs, also significantly suppressed the sprouting by 67% and 60% respectively in the ipsi- and contra-lateral DRGs. Delivery of exogenous BDNF into an intact L5 DRGs resulted in an increase in the sprouting by 4.2-fold. Our results clearly indicate that BDNF, synthesized in and secreted from the DRGs, is involved in the sympathetic sprouting in the DRG following the peripheral nerve injury.
RESUMO
Image contrast in intermolecular double-quantum coherence (iDQC) imaging of a pig tail was investigated on a 7.05-T microimaging scanner. In addition to TR (repetition time) and TE (echo time), the time interval tau between radio frequency pulses during iDQC evolution and the areas under the iDQC-encode gradients in the iDQC imaging sequence were also used to manipulate image contrast. When suitable imaging parameters were selected, images with unique contrast, such as those with certain regions of the sample highlighted, were obtained without using contrast agents. The effects of iDQC-encode gradient on image contrast were studied quantitatively, and the unique contrast imposed by the related diffusion weighting was also shown. Experimental results demonstrated that the iDQC images have contrast fundamentally different from the conventional single-quantum coherence images.
Assuntos
Meios de Contraste , Imageamento por Ressonância Magnética/métodos , Teoria Quântica , Cauda/anatomia & histologia , Animais , Medula Óssea/anatomia & histologia , Processamento de Imagem Assistida por Computador , Músculo Esquelético/anatomia & histologia , Coluna Vertebral/anatomia & histologia , SuínosRESUMO
OBJECTIVES: We recently showed that the peritoneal surface layer may be an important barrier in modulating peritoneal membrane permeability. In the present study, we investigated the relationship between an increased peritoneal transport rate and the peritoneal surface layer. METHODS: Male Sprague-Dawley rats (n = 8) received intraperitoneal injections of 4.25% glucose dialysate daily for 1 week. Forty-eight hours after the last injection, a 4-hour dwell study using 25 mL 4.25% glucose dialysate was performed in each rat. The results were compared with those from control rats that received no intraperitoneal injections (n = 8). The peritoneal fluid and small-solute transport characteristics were evaluated. The peritoneal surface layer was studied using an electron microscope. The phospholipids content of the dialysate was also evaluated. RESULTS: Peritoneal fluid removal was significantly reduced in the daily injection group (30.6 +/- 1.3 mL) as compared with the control group (38.2 +/- 0.6 mL). The peritoneal fluid absorption rate and small-solute transport rate were also significantly higher in the daily injection group as compared with the control group. The amounts of phospholipids in the dialysate were significantly lower in the daily injection group--especially the quantity of phosphatidylcholine. However, lysophosphatidylcholine increased significantly in the daily injection group. Electron microscopy showed that the peritoneal surface layer was almost completely gone in the daily injection group, but that a dense and thick (average 4 microm) peritoneal surface layer was present on the top of the mesothelial cells in the control group. CONCLUSIONS: Our results suggest that daily injection of hypertonic glucose dialysate significantly increased the peritoneal transport rate. The increased peritoneal transport rate was associated with a significant reduction in the peritoneal surface layer and the phospholipids content of the dialysis effluent.
Assuntos
Peritônio/metabolismo , Peritônio/ultraestrutura , Animais , Transporte Biológico , Soluções para Diálise/química , Soluções para Diálise/farmacologia , Epitélio/ultraestrutura , Glucose/administração & dosagem , Solução Hipertônica de Glucose/farmacologia , Masculino , Microscopia Eletrônica , Peritônio/efeitos dos fármacos , Permeabilidade , Fosfolipídeos/análise , Ratos , Ratos Sprague-DawleyRESUMO
Dialysate concentration of phospholipids has been used to monitor peritoneal membrane status. However, we recently found that the peritoneum has a surface layer in which phospholipids may be the main constituent. Therefore, in this study, we compared the phospholipids composition of peritoneal dialysate and of the peritoneal surface in rats. Eight male Sprague-Dawley rats were used in the study. Five rats received an intraperitoneal injection of 25 mL 4.25% glucose dialysis solution. After four hours, the rats were killed, and the dialysate was drained completely. Then 20 mL of Folch solution was infused into the peritoneal cavity for 30 seconds and drained completely. The other three rats received the Folch solution without dialysis. The effluent and Folch solution were then processed for phospholipids analysis using high performance thin-layer chromatography (HPTLC). The total phospholipids content was ten times higher in the surface layer than in the dialysate effluent. In the effluent, four clearly different components were seen: lysophosphatidylcholine (LPC), sphingomyelin (SM, 29%), phosphatidylcholine (PC, 66%), and phosphatidylinositol (PI, 4.5%). However, in the surface layer, as well as LPC, SM (20.6%), PHC (47%), and PI (6.3%), two additional components were seen, phosphatidylserine (PS, 17.1%) and phosphatidylethanolamine (PE, 8.9%). The quantity of phospholipids in the peritoneal surface of non dialyzed rats was similar to the total quantity of phospholipids (in effluent and in the peritoneal surface) of dialyzed rats. Our results suggest that: (1) a surface layer is present on the peritoneum; this layer could well be extracted by Folch solution; and, with appropriate incubation time, one can separate the surface layer without damaging the mesothelial cells; (2) the composition of phospholipids in the effluent is different from that in the peritoneal surface layer, which contains membrane phospholipids (PS and PE); (3) shielding from the peritoneal surface may be the main reason for the presence of phospholipids in the dialysate.
Assuntos
Soluções para Diálise/química , Diálise Peritoneal , Peritônio/química , Fosfolipídeos/análise , Animais , Cromatografia Líquida de Alta Pressão , Lisofosfatidilcolinas/análise , Masculino , Fosfatidiletanolaminas/análise , Fosfatidilinositóis/análise , Fosfatidilserinas/análise , Ratos , Ratos Sprague-Dawley , Esfingomielinas/análiseRESUMO
CD40-CD40 ligand (CD40L) interaction plays an important role in macrophage/monocyte-mediated inflammatory processes by up-regulating cytokine production by macrophages/monocytes and by preventing macrophage apoptosis at the inflammation sites. The present study investigated the possible regulation of CD40L expression in peritonitis during continuous ambulatory peritoneal dialysis (CAPD). We used fluorescence-activated cell sorter (FACS) analysis to detect CD40L expression on macrophages obtained from peritoneal dialysate. Our results showed that CD40L expression on macrophages was significantly increased in a peritonitis group (4.62 +/- 6.54) as compared to a control group (0.76 +/- 0.30, p < 0.01). The CD40L-positive cells were also significantly increased during peritonitis (97.86% +/- 1.67% in the peritonitis group as compared to 73.10% +/- 26.94% in the control group, p < 0.05). After successful treatment, the expression of CD40L was significantly reduced (3.66 +/- 1.12 vs 1.05 +/- 0.02, p < 0.05). We conclude that functionally expressed CD40L on macrophages may take part in acute inflammatory response during peritonitis in CAPD and may play an important role in the local defense against infection in the peritoneal cavity.