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Nitrogen is an essential nutrient for yeast cells on ethanol fermentation. In order to reveal the promoting mechanisms of organic nitrogen sources on the ethanol fermentation by yeast, Saccharomyces cerevisiae, laser tweezers Raman spectroscopy and single-cell analysis techniques were used to monitored the kinetic of intracellular bio-macromolecules of individual cells during fermentation with urea, yeast extract, ammonium nitrate or ammonium sulfate as the sole nitrogen source. Major results from this work were as follows. (1) Organic nitrogen sources had a promoting effect on the ethanol fermentation, the fermentation with urea and yeast extract reached the maximum concentration of ethanol in 14-18 h. ( 2 ) There were no apparent lag phases for the RNA synthesis of yeast cells cultured with urea and yeast extract. The averaged Raman intensity of yeast cells at peak of 782 cm-1 in the early stage of fermentation was stronger than that of cultured with ammonium nitrate and ammonium sulfate. The maximum was about 1. 9-2. 1 times of the initial intensity for urea or yeast extract, but 1. 2-1. 4 times for ammonium nitrate and ammonium sulfate. (3) The secondary structure of proteins of partial cells cultured with yeast extract was dominated byβ-sheet, while cells cultured with other nitrogen sources were dominated by α-helix absolutely. These results bring us the conclusion that the improving effect of organic nitrogen sources such as urea and yeast extract on ethanol fermentation by Saccharomyces cerevisiae may be due to that the organic nitrogen sources can shorten the lag phase of yeast cells, promote the RNA synthesis, and promote the transcription and expression of related genes.
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Objective To evaluate the effect of 8% emulsified isoflurane preconditioning on renal ischemia-reperfusion (I/R) injury in rats.Methods Thirty-two male Sprague-Dawley rats,aged 10-13 weeks,weighing 220-300 g,were randomly divided into 4 groups (n =8 each):sham operation group (group S); I/R group;emulsified isoflurane preconditioning group (group E) ; intralipid preconditioning group (group I).Renal ischemia was induced by occlusion of the left renal pedicle for 45 min with atraumatic microclips followed by 3 h reperfusion.8 % emulsified isoflurane and 30 % intralipid 4 ml· kg-1· h-1 were infused intravenously for 30 min followed by 15 min washout before renal UR in groups E and I,respectively.Arterial blood samples were taken at 3 h of reperfusion to determine the concentrations of serum creatinine (Cr),cystatin C (Cys C),TNF-α,IL-6 and IL-10.The animals were then sacrificed and left kidneys were removed and stained with hematoxylin-eosin for microscopic examination and assessment of necrosis of renal proximal convoluted tubules (0 =normal,4 =necrosis of whole segment of proximal convoluted tubules).Results Compared with group S,the serum Cr,Cys C,TNF-α,IL-6 and IL-10 concentrations and severity of necrosis of renal proximal convoluted tubules were significantly increased in groups I/R,E and I (P ＜ 0.05).The serum Cr,Cys C,TNF-α and IL-6 concentrations and severity of necrosis of renal proximal convoluted tubules were significantly lower,while the serum IL-10 concentration was higher in group E than in groups I/R and I (P ＜0.05).There was no significant difference in the indexes mentioned above between groups L and I/R (P ＞ 0.05).The damage to renal tissues was less serious in group E than in groups I/R and L.Conclusion Preconditioning with 8 % emulsified isoflurane can attenuate renal I/R injury by inhibiting inflammatory responses in rats.
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Objective To investigate the effects of direct peritoneal resuscitation (DPR) with sodium pyruvate from hemorrhagic shock (HS) on intestinal injury in rats.Methods Fifty SPF male Sprague-Dawley rats,weighing 200-250 g,were used in this study.The animals were anesthetized with 1％ pentobarbital sodium 40 mg/kg,tracheostomized and mechanically ventilated.Femoral artery was cannulated for mean arterial pressure (MAP) monitoring,blood-letting,blood sampling and fluid infusion.HS was induced according to the method described by Wiggers.MAP was maintained at 35-40 mm Hg for 60 min.The animals were then randomly and equally divided into 5 groups:sham operation group (group S) ; conventional resuscitation group (group CR) ; DPR with different fluid groups (DPRt-3 groups).In group CR,at 1 h after HS,the animals were resuscitated with infusion of the blood withdrawn and normal saline (the volume was 2 times volume of blood loss).In DPR1-3 groups,conventional resuscitation was performed,at the same time,1.5 ％ glucose-based peritoneal dialysis solution containing lactate,1.5％ glucose-based peritoneal dialysis solution containing lactate (40.00 mmol/L),and 1.5％ glucosebased peritoneal dialysis solution containing high lactate (80.00 mmol/L) 20 ml were infused intraperitoneally over 30 min,respectively.MAP was recorded before blood letting,at 5,30 and 60 min of HS,and at 5,30,60,90 and 120 min after the end of resuscitation.At 120 min after the end of resuscitation,the lactate level in the arterial blood was measured.The animals were then sacrificed.Small intestinal samples were obtained for determination of malondialdehyde (MDA) content,myeloperoxidase (MPO) activity and tumor necrosis factor-α (TNF-α) expression,and for microscopic examination.The damage to the small intestinal mucosa was assessed and scored.Results Compared with MAP before blood letting,MAP during HS was significantly decreased,and no significant change in MAP was found after resuscitation in CR and DPR1-3 groups (P ＜ 0.05).The lactate level in the arterial blood,MDA content,MPO activity,TNF-α expression and intestinal mucosal damage scores were significantly higher in CR and DPR1-3 groups than in S group (P ＜ 0.05 or 0.01),while lower in DPR1-3 groups than in CR group (P ＜0.01),and in DPR2,3 groups than in DPR1 group (P ＜ 0.05 or 0.01).The lactate level in the arterial blood,MDA content and TNF-α expression were significantly lower in DPR3 group than in DPR2 group (P ＜ 0.05 or 0.01).Conclusion Direct peritoneal resuscitation with sodium pyruvate can reduce the intestinal injury induced by HS and inhibition of lipid peroxidation and inflammatory responses is involved in the mechanism in rats.
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Objective:To investigate the plastic method of glottis carcinoma in surgery. Method:Retrospectly analyzed 29 patients with T_2 ,T_3 glottis carcinoma who admited in our department From 1996 to 2004. All of them were treated with the displacement of ventricular bands-epiglottis mucosal flap in the surgical management of glot-tis carcinoma. The tumour was primarily from vocal cords, and not exceeded 2cm. Result: All cases were success-fully renovated laryngeal cavity with the displacement of ventricular bands-epiglottis mucosal flap and followed up for 5 years after operation. Three years survival rate was 86.2% ,5 years survival rate was 78.9% ,and tube draw-ing rate was 100%. Conclusion: With this method, surgery would be simplified and the patients would keep the voiced function and swallowing function.
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OBJECTIVE@#To investigate the plastic method of glottis carcinoma in surgery.@*METHOD@#Retrospective analyzed 29 patients with T2, T3 glottis carcinoma who admitted in our department From 1996 to 2004. All of them were treated with the displacement of ventricular bands-epiglottis mucosal flap in the surgical management of glottis carcinoma. The tumour was primarily from vocal cords, and not exceeded 2 cm.@*RESULT@#All cases were successfully renovated laryngeal cavity with the displacement of ventricular bands-epiglottis mucosal flap and followed up for 5 years after operation. Three years survival rate was 86.2%, 5 years survival rate was 78.9%, and tube drawing rate was 100%.@*CONCLUSION@#With this method, surgery would be simplified and the patients would keep the voiced function and swallowing function.