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BACKGROUND: Regeneration of injured axons in adult mammalian central nervous system (CNS) is not spontaneous. Nogo is a major inhibitory molecule contributing to axon regeneration failure. The molecular mechanisms of Nogo inhibition of axon regeneration are not completely understood. To further investigate the underlying mechanisms, we studied the effects of Nogo-p4, a 25-amino acid core inhibitory fragment of Nogo, on nerve growth factor (NGF)-induced TrkA signaling. METHODS: NGF-differentiated PC12 cells were used as cell models. The effects of Nogo-p4 on two key components of TrkA signaling, phosphorylated Erk1/2 and Akt, were analyzed by western blot. Co-immunoprecipitation experiments were performed to detect the formation of NgR1/p75 complexes. Neurite growth was quantified by measuring the neurite length. RESULTS: Nogo-p4 did not significantly affect TrkA signaling induced by 100 ng/ml NGF, but signaling was suppressed when an NGF concentration of 5 ng/ml was used. Further investigation demonstrated that Nogo-p4 affected TrkA signaling in an NGF concentration-dependent manner. Nogo-p4 suppression of TrkA signaling was strong at low (1 and 5 ng/ml), moderate at intermediate (25 ng/ml), but absent at high (50 and 100 ng/ml) NGF concentrations. NEP1-40 attenuated, and NgR1 overexpression enhanced, Nogo-p4 suppression of TrkA signaling induced by low concentrations of NGF. High but not low concentrations of NGF reduced the formation of NgR1/p75 complexes triggered by Nogo-p4. Nogo-p4 strongly inhibited neurite growth induced by low rather than high concentrations of NGF. CONCLUSION: Nogo-p4 binding with NgR1 suppresses TrkA signaling induced by low concentrations of NGF in differentiated PC12 cells. Suppression of NGF-induced TrkA signaling may be another mechanism by which Nogo inhibits neurite growth.
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To establish a method for detecting microdialysis recovery of tetramethylpyrazine (TMP) and ferulic acid (FA) and investigating the influencing factors, providing the basis for further in vivo microdialysis experiments. The concentration of FA and TMP in dialysates were determined by high pressure liquid chromatography ( HPLC) and probe recovery were calculated respectively. The influence of the flow rates, medium concentration, temperature and in vivo probe stability on the recovery of FA and TMP were investigated by using concentration difference method (incremental method and decrement method). The recovery obtained by incremental method were similar to by decrement method. The in vitro recovery rate of FA and TMP decreased with the increase of 1-2.5 µL min(-1), and increased obviously with the temperature of 25-42 degrees C under the same conditions. The concentration of FA and TMP had no obvious effect on the probe recovery under the same flow rate. In addition, the recovery of TMP and FA remained stable and showed similar trends under the condition of four concentration cycles, indicating that the intra day reproducibility of the concentration difference method was good. The recovery of brain microdialysis probes in vivo 8 h maintained a relatively stable, but certain differences existed between different brain microdialysis probes, demonstrating that each probe was required for recovery correction in vivo experiment. Microdialysis sampling can be used for the local brain pharmacokinetic study of FA and TMP, and retrodialysis method can be used in probe recovery of FA and TMP in vivo.
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Encéfalo/metabolismo , Ácidos Cumáricos/aislamiento & purificación , Microdiálisis/métodos , Pirazinas/aislamiento & purificación , Animales , Cromatografía Líquida de Alta Presión , Ácidos Cumáricos/análisis , Ácidos Cumáricos/farmacocinética , Medicamentos Herbarios Chinos , Humanos , Pirazinas/análisis , Pirazinas/farmacocinética , RatasRESUMEN
OBJECTIVE: To evaluate three different methods for controlling presacral massive bleeding during pelvic operations. METHODS: Clinical data of 11 patients with presacral massive bleeding during pelvic operation at The Sixth Affiliated Hospital of Sun Yat-sen University and 157 Branch Hospital of Guangzhou General Hospital of Guangzhou Military Command from January 2001 to January 2016 were analyzed retrospectively. Hemostasis methods for presacral massive bleeding during operation included gauze packing (whole pressure), drawing pin (local pressure) and absorbable gauze (absorbable gauze was adhered to bleeding position with medical glue after local pressure). Efficacy of these 3 methods for controlling bleeding was evaluated and compared. RESULTS: Ten patients were male and 1 was female with average age of 65.2 (40 to 79) years old. Eight cases were rectal cancer, 2 were presacral malignancies and 1 was rectal benign lesion. Bleeding volume during operation was 300 to 2 500 (median 800) ml. From 2001 to 2012, 4 cases received gauze packing, of whom, 3 cases were scheduled Dixon resection before operation and then had to be referred to Hartman resection; 3 cases died of systemic failure due to postoperative chronic errhysis and infection, and 1 underwent re-operation. At the same time from 2001 to 2012, 5 cases received drawing pin, of whom, bleeding of 3 cases was successfully controlled and Dixon resection was completed. In other 2 cases with hemostasis failure, 1 case underwent re-operation following the use of gauze packing, and another 1 case received absorbable gauze hemostasis. All the 5 patients were healing. From 2013 to 2016, 2 cases completed scheduled anterior resection of rectum after successful hemostasis with absorbable gauze and were healing and discharged. CONCLUSIONS: Gauze packing hemostasis is a basic method for controlling presacral massive bleeding. Drawing pin and absorbable gauze hemostasis are more precise and may avoid the change of surgical procedure. But drawing pin has the possibility of hemostasis failure. Absorbable gauze hemostasis with medical adhesive is effective, simple and fast.
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Pérdida de Sangre Quirúrgica , Hemostasis Quirúrgica , Neoplasias del Recto/cirugía , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pelvis , Recto , Estudios RetrospectivosRESUMEN
OBJECTIVE: To observe the effects of peritoneal lavage with povine-iodine on prevention of sepsis after exposure of peritoneal cavity to sea water in rat. METHODS: Eighty-four SD rats were randomly divided into two groups, and the peritoneal cavity was exposed to sea water. Rats in group A were not treated (group A, n=42), and the peritoneal cavity was lavage with povine-iodine in group B (n=42). Plasma levels of endotoxin and tumor necrosis factor (TNF) were measured preimmersion, and 0, 12, 24 hours after seawater immersion (n=6), and positive incidence of blood bacterial culture was performed (n=18 in each group) in groups A and B. RESULTS: 1. Plasma levels of endotoxin and TNF in group A and B were increased significantly after exposure of peritoneal cavity to sea water (compared with baseline values, all P<0.05). Plasma levels of endotoxin and TNF in group B became lower than those in group A from 12 hours after seawater immersion (P<0.05 or P<0.01). 2. Positive incidence of bacterial culture in group B was 16.7 % (3/18) and it was lower than that in group A (77.8 % (14/18), P<0.01). CONCLUSION: Povine-iodine lavage in the peritoneal cavity can reduce levels of plasma endotoxin and TNF, and lower positive incidence of bacterial culture in rats after exposure of peritoneal cavity to sea water, thereby preventing the development of postoperative sepremia.
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Lavado Peritoneal/métodos , Complicaciones Posoperatorias/prevención & control , Sepsis/prevención & control , Animales , Antiinfecciosos Locales/farmacología , Modelos Animales de Enfermedad , Yodo/farmacología , Masculino , Cavidad Peritoneal/lesiones , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Agua de Mar , Infección de la Herida Quirúrgica/prevención & control , Resultado del TratamientoRESUMEN
OBJECTIVE: To determine hypotonic liquid containing colloid on hemorrhagic dogs with celiac seawater immersion wound. METHODS: Thirty-five dogs were randomly divided into five groups: control group (group A), 0.9% NaCl therapy group (group B) and 0.45% NaCl therapy group (group C), 5% glucose therapy group(group D) and hypotonic liquid containing colloid therapy group (group E). Changes of mean artery pressure (MAP), cardiac output (CO), urine volume, plasma osmotic pressure and pathologic changes of lung and brain were observed. RESULTS: hypotonic liquid containing colloid could effectively ameliorate MAP and CO, improve urine volume, decrease plasma osmotic pressure and prevent occurrence of lung and brain edema. CONCLUSION: Hypotonic liquid containing colloid can exert satisfactory therapeutic effects on hemorrhagic dogs with celiac seawater immersion wound.
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Soluciones Hipotónicas/uso terapéutico , Agua de Mar/efectos adversos , Choque Hemorrágico/terapia , Animales , Presión Sanguínea , Gasto Cardíaco , Coloides , Perros , Inmersión , Presión Osmótica , Choque Hemorrágico/patologíaRESUMEN
AIM:To investigate the effect of gastroenteric reconstruction on the nutritional status of patients with gastric cancer after total gastrectomy.METHODS: From 1989-1994, nutritional status was studied in 24 patients, including 12 patients with the gastric reservoir and pyloric sphincter reconstruction (GRPS), 7 with Braun's esophago-jejunostomy (EJ) and 5 with Lawrance's Roux en Y reconstruction (RY).The ability of these patients to ingest and absorb the amount of nutrients was examined and compared, and metabolic balance test was performed to compare the efficiency of those patients to accumulate and use the absorbed nutrients.RESULTS:In the controlled hospital situation, the amount of food ingested by all the patients was greater than that required for maintenance of ideal body weight. In direct contrast, food intake in most patients with EJ or RY reconstruction significantly decreased when the patients returned home and that in EJ patients it was the lowest. The overgrowth of anaerobic bacteria was found in the jejunum in the patients with EJ and RY, due mainly to food stasis in the duodenum or in the Roux limb,caused by the operative procedure itself. In patients with GRPS,because of restoring of the alimentary continuity according to the normal digestive physiologic characters, all the nutritional parameters could fall in the normal range.CONCLUSION:The most common mechanism responsible for postoperative malnutrition was inadequate food intake. Having solved the problem of alkaline reflux esophagitis, it is imperative to preserve the duodenal food passage to reduce malabsorption and other complications after total gastrectomy.