Different types of acids from fermentation environment or industrial microorganisms exist during fermentation process. Acids may inhibit growth and metabolism of industrial strains, namely acid stress. The tolerance mechanisms of acid stress include regulation of intracellular proton concentration, protection and restoration of intracellular macromolecules, changes in cell membrane composition and acid stress response at whole cell level. Screening and modification methods have been applied to improve acid-stress tolerance of industrial strains for decades. In this review, we provide insights into acid-stress tolerance of industrial microorganisms and address the modification of microbial pathways to improve acid-stress tolerance.
Acids ; chemistry ; Fermentation ; Hydrogen-Ion Concentration ; Industrial Microbiology ; Metabolic Engineering

Objective To study the influence of laparoscopic gastric surgery on the gut barrier function (GBF).Methods There were 64 gastric cancer patients undergoing respectively laparoscopic radical procedures (32 cases) and open gastric surgery (32 cases).Blood was drawn on day one before surgery,day 1,day 3 and day 7 after the surgery for the measurement of plasma D-lacate and plasma diamine oxidase activity by using ultraviolet spectrophotometry.Results There was no statistical difference among demographic,clinicopathological characterastics between the two groups (P ＞ 0.05).The difference on the operative time,blood loss and the time starting to take food after the surgery was significant between the two groups,P ＜ 0.05.The differences of plasma D-lacate level and the diamine oxidase (DAO) on perioperatively respective all time points were not significant between the two groups,P ＞ 0.05.Conclusion Laparoscopic radical gastrectomy is comparable to open procedures in causing damage to patient's gut barrier functions.

Objective Adult isolated ACTH deficiency ( IAD) is an uncommon and underestimated disorder with high rate of misdiagnosis.This paper aimed to analyze and summarize the clinical features of 6 patients with IAD to have deeper understanding of the disease. Methods Retrospective analysis was made on the data of 6 IAD cases enrolled in Nanjing Hospital of Nanjing Medical University from 2007 to 2015.Statistical analysis was made on the clinical manifestations, therapeutic schemes, laboratory and imaging results, along with outpatient follow-up(ranging from 0.5-10 years), in order to analyze clinical efficacy and prognosis result. Results Of 6 IAD patients, 4 patients showed main symptoms of long-term fatigue, anorexia, weight loss;5 patients were with differ-ent degrees of hypoglycemia (fasting blood glucose2.70 [1.2-3.0]mmol/L), among which 3 had hypoglycemic coma (fasting blood glucose <1.8mmol/L), 1 had chronic hypoglycemia and 1 had asymptomatic hypoglycemia( asymptomatic hypoglycemia by continu-ous glucose monitor system).4 of them had refractory hyponatremia (Serum Na+117 [110-120]mmol/L).ACTH values of all the patients were less than 0.01ng/L.After glucocorticoid replacement therapy, all the patients were followed up for six months after treat-ment and cortisol rhythm, plasma cortisol, urine cortisol, fasting blood glucose, serum sodium of the patients were in normal range, but still at a low level of ACTH. Conclusion The clinical manifestation of IAD is characterized as hypoglycemia, hyponatremia, low ACTH with other normal pituitary hormones.Long-term glucocor-ticosteroid therapy has favorable prognosis for patients with adult isola-ted ACTH deficiency.

Objective To observe the effect of ghrelin on the expression of procollagen type Ⅰ and alpha smooth muscle actin (α-SMA) synthesis in vitro cultured human hepatic stellate cell (HSC-LX2) stimulated by Platelet-derived growth factor-BB (PDGF-BB).Besides,the effect of PI3K-AKT pathway was studied.Methods Cultured LX2 were intervented and jointing intervented according to the different ghrelin concentration by ghrelin and PDGF:control group,0.1 μmol/L Ghrelin group,10 μg/L PDGF group,0.05 μmol/L Ghrelin +10 μg/L PDGF group,0.1 μmol/L Ghrelin + 10 μg/L PDGF group,0.15 μmol/L Ghrelin + 10 μg/L PDGF group.Culture HSC-LX2 in vitro,joint intervention cells with different concentrations.Procollagen Ⅰ mRNA expression were detected by Polymerase chain reaction (PCR),besides,α-SMA and AKT expression were detected by Western blot in each groups.After treatment by PI3K specific inhibitor LY294002 in LX2,three groups were divided into PDGF,Ghrelin + PDGF and LY294002 + Ghrelin +PDGF.Procollagen Ⅰ mRNA expression were detected by PCR,and α-SMA was detected by Western blot.Results PCR results showed that procollagen Ⅰ expression in PDGF treated group was significantly higher than the control group ((6.91 ± 0.46) vs.(1.00 ± 0.08),P ＜ 0.05),so PDGF can promote the expression of procollagen type Ⅰ.Procollagen Ⅰ mRNA expression between ghrelin group(0.60±0.13) and blank control group had no significant change(P＞0.05).Procollagen Ⅰ mRNA expression between different concentrations of Ghrelin and PDGF (3.11 ± 0.28,2.03 ±0.23,0.70 ± 0.06) was significantly reduced than PDGF group.The difference was statistically significant (P ＜0.05),and with the increase of the ghrelin concentration of the inhibition,the effect was more obvious in a concentration dependent manner.Western blot showed that α-SMA expression was lower in Ghrelin +PDGF group than PDGF group.AKT expression was higher in Ghrelin +PDGF group than PDGF group,indicating that PI3K-AKT may participate in the anti-fibrosis effect of ghrelin in LX2.After treatment of PI3K specific inhibitor,procollagen Ⅰ expression in LY294002+Ghrelin +PDGF group was significantly higher than Ghrelin +PDGF group((4.13±0.21) vs.(2.34±0.25),P＜0.05).Western blot also showed that α-SMA expression was higher in LY294002 + Ghrelin + PDGF group than Ghrelin + PDGF group.It was suggested that after inhibitation of PI3K,the anti-fibrosis effect of ghrelin in LX2 was attenuated.Conclusion After stimulated by PDGF in hepatic stellate cell,ghrelin can inhibit procollagen type Ⅰ and alpha-SMA synthesis in the process of hepatic fibrosis via PI3K-AKT pathway,thus,ghrelin may become one of the new ways of prevention and treatment of liver fibrosis.

Objective To explore the expression and significance of Rac1 and WAVE2 protein in glomerulus of high-
fat diet induced C57BL/6J model mice. Methods Thirty-two male C57BL/6J mice (3-week old) were randomly assigned into two groups(16 in each group). The control group was fed with basic diet (10%fat) for 4 weeks. The high-fat diet group was fed with high-fat diet (60%fat) for 4 weeks. The kidney morphological changes were examined by HE and PAS staining. The expressions of Rac1 and WAVE2 protein were examined by Western blot and immunohistochemistry analysis. Results HE and PAS results showed that there were glomeruli mesangial matrix hyperplasia and exudation in high-fat diet group compared with control group. The immunohistochemistry and Western blotting results showed that expressions of Rac 1 and WAVE2 in glomerulus were both increased in high-fat diet group compared with those of control group. Conclusion Rac1 and WAVE2 protein may be involved in glomerular injuries induced by high-fat diet.

Objective To study the immunoregulatory activity of eucommia ulmoides oliv polysaccharides (EOP) on immunodepressive mice. Method The immunodepressive mice model was established with cyclophosphamide (CY) treated. EOP was given with different doses, and mouse weight, thymus index, spleen index, abdominal cavity macrophage engulfing rates, engulfing index were measured. Result 300 grams Eucommia ulmoides Oliv crude drugs after withdraw separate gained 9.3 grams polysaccharides. After CY injection, the mouse weight, chest gland index, abdominal cavity macrophage swallowing rate, phagocytic count reduced. EOP could resist the mouse body weight drop induced by CY, elevate the thymus index of immunity low mouse, obviously increase mouse abdominal cavity macrophage engulfing rates and engulfing index (P

BACKGROUND:The type AO-C1 thoracolumbar acute spine injury is a kind of high-energy instable injury, can cause thoracolumbar fracture-dislocation, and mainly associated with spinal nerve injury. Generaly, al needs to posterior open reduction, decompression, bone graft fusion and multiple-segmental internal fixation of pedicle screw rod system, which causes excessive loss of spinal movement segment and a large number of application of internal fixators. OBJECTIVE:To evaluate the treatment effect of posterior pedicle screw mono-segmental internal fixation for treatment of the type AO-C1 thoracolumbar vertebrae fracture-dislocations. METHODS:From January 2008 to December 2013, 17 cases of type AO-C1 thoracolumbar fracture-dislocation were folowed up. Al patients were treated with one-stage posterior open reduction and pedicle screw-rod fixation. Of them, eight cases received four screws and two rods for single-segment fixation in upper and lower vertebrae adjacent to intervertebral space after dislocation (4-screw 2-rod group). Nine cases received eight screws and two rods for multiple-segment fixation in the upper and lower vertebrae adjacent to intervertebral space after dislocation (8-screw 2-rod group). Operative time and intraoperative blood loss were compared between the two groups. The Cobb’s angle was measured on lateral X-ray film of two groups preoperatively and 1 week postoperatively and during the final folow-up. The neurological function was evaluated by Frankel classification. The visual analogue scale was adopted to assess the degree of low back pain. RESULTS AND CONCLUSION:Patients were folowed up for 1 to 5 years. Significant differences were detected in the operative time between the two groups, and operative time was better in the 4-screw 2-rod group than in the 8-screw 2-rod group (P < 0.05). No significant difference was found in intraoperative blood loss between the two groups. The deformity of fracture-dislocation had been corrected, and the pain of low back had significantly relieved in al patients after fixation. According to Frankel classification, two cases at Grade A were improved to Grade E, but eight cases at Grade A got no improvement after treatment. Two cases at Grade B were also improved to Grade E at the final folow-up. Significant differences in Cobb’s angle and visual analogue scale were detectable at 1 week postoperatively and during final folow-up as compared with preoperatively (P < 0.05), but no significant difference was visible between final folow-up and 1 week postoperatively. No significant difference in Cobb’s angle and visual analogue scale was observed between the 4-screw 2-rod group and 8-screw 2-rod group. Results indicate that there was no significant difference in the clinical efficacy between 4-screw 2-rod single-segment and 8-screw 2-rod multiple-segment fixation for treating type C1 thoracolumbar vertebrae fracture-dislocation. Therefore, AO-C1 thoracolumbar vertebrae fracture-dislocation could be treated with 4-screw 2-rod single-segment reduction fixation.

BACKGROUND:Traditional internal fixation for thoracolumbar vertebral fractures easily causes poor vertebral reduction, and postoperative vertebral height loss easily appears.
OBJECTIVE:To analyze the feasibility of lateral-position pedicle screw placement in spinal surgeryvia combined anterior-posterior approaches.
METHODS: A total of 36 cases undergoing spinal surgical operation in the Baoji City Chinese Medicine Hospital from February 2013 to October 2014 were enroled in this study. The patients were divided into two groups according to the method of repair. 18 patients in the control group received prone-position pedicle screw placement, and 18 patients in the experimental group received lateral-position pedicle screw placementvia combined anterior-posterior approaches. Postoperative CT and X-ray examinations compared the adverse rate of screw placement and the rate of nerve root injury between the two groups. Operation time, length of stay, time of beginning movement, intraoperative blood loss and American Spinal Injury Association impairment scale score were compared between the two groups.
RESULTS AND CONCLUSION:Significant differences in the adverse rate of screw placement and the rate of nerve root injury were detected between the two groups (P < 0.05), and the adverse rate of screw placement and the rate of nerve root injury were better in the experimental group than in the control group. Operation time, length of stay, and time of beginning movement were significantly better in the experimental group than in the control group (P < 0.05). Intraoperative blood loss was significantly lower in the experimental group than in the control group (P < 0.05). American Spinal Injury Association impairment scale scores were significantly higher in the experimental group than in the control group (P < 0.05). These findings confirm that lateral-position pedicle screw placementvia combined anterior-posterior approaches in spinal surgery can reduce intraoperative trauma, shorten the length of hospital stay, and promote functional recovery of spinal cord.

Objective Objective To discuss the teaching pattern of experimental classes,and to probe the deep development of the functional subject about experimental teaching and the approach of cultivating talents.Methods Student volunteers participated in a series of activities in the summer vocation including experimental design,implementation,results reports and discussion.Results The reflection of students for the learning pattern were as follows: providing a good opportunity of learning(100%);helpful for improving the abilities of finding and dealing with problems(87.50%);different from the past physiological labs including representing special subject characteristics(93.75%),more precise form(68.75%),excellent interaction between teachers and students(75%);improving the manipulation abilities(93.75%).Deficiencies: the experimental conditions were not good enough(68.75);the teachers should give more guidance in theory and techniques(50%).Conclusions The is a meaningful educational form.Under the new experimental teaching pattern,students could use basic medical knowledge and experimental techniques to design and accomplish experiments voluntarily.This pattern is propitious for cultivating integrated capabilities of students,helping them to learn the basic approach and technique means.And it will have much developing space in experimental education in future.

Objective:To determine the half lethal dose(LD50) of paraquat in rats and to establish a relatively safe and stable pathological animals model of pulmonary fibrosis.Methods: Ninety-six SD rats totally in half genders.Fifty SD rats in half genders were randomly divided into 5 groups,each had 10 rats.Feed the rats with different doses of liquor of paraquat intraperitoneally one time and definite the half lethal dose of one and two weeks.After that,prepare another forty-six SD rats,also in half genders,as intonication group,twenty-eight rats were treated with the liquor of paraquat in dosage of 18 mg/kg intraperitoneally.As control group,sixteen rats were treated with equivalent volume of normal saline.Observe the toxic symptom daily and rats were sacrificed on day 1,3,5,7,14,21,28,35 and 42 respectively for the histological examination.Results: The half lethal doses of intraperitoneal paraquat of 1 and 2 weeks were 18.27 and 17.29,with 95% confidence intervals of 16.61-20.09 and 15.99-18.67,respectively.After intraperitoneal paraquat injection at the dose of 18 mg/kg,typical toxic symptoms were observed at different times in the rats.The whole process of acute lung injury and fibrosis induced by paraquat intoxication could be seen with the naked eyes or under the light microscope.Conclusion: Paraquat has a strong toxicity to rats.A proper dose of paraquat solution can not only reduce the number of experimental rats,but also induce typical pulmonary fibrosis in rats.