刚果红法测定麦汁和啤酒中的β-葡聚糖

研究了以刚果红分光光度法测定麦汁及啤酒中的β－葡聚糖，探讨了实验条件，在ｐＨ８．０的条件下，刚果红和水溶性的β－葡聚糖（分子量１０３～１０４）形成有色物质，摩尔吸光系数为９．６４×（１０３～１０４）Ｌ·ｍｏｌ－１·ｃｍ－１，当参加反应的２．０ｍｌβ－葡聚糖溶液中β－葡聚糖的含量为０～１００μｇ时，反应液吸光度的变化符合比耳定律，变异系数１．１％～５．１％，标样的回收率在９０．２％～９８．６％之间，测定麦汁或啤酒中的β－葡聚糖时，变异系数为３．７％左右。     

电导率监测在啤酒发酵过程中的应用

采用电导率测量的方法对啤酒发酵过程进行了研究,通过计算机的辅助实现了发酵过程中电导率的在线监测.结果表明:在啤酒发酵过程中电导率的变化遵循一定的规律性,并且将电导率与还原糖、酵母数等过程参数进行数学建模,同时将麦汁浓度、酵母代数对电导率的影响进行了比较.     

低双乙酰啤酒酵母的选育

以两株青岛啤酒酵母ｃ－０２和ｃ－０３为出发菌株，经紫外线诱变后挑出甲磺隆抗性菌株，经过实验室菌种分离、筛选、发酵及双乙酰驯养等步骤选育出一株②＃菌，１２°Ｐ麦汁经１０００Ｌ小罐１１℃低温发酵，双乙酰峰值为０．３５ｍｇ／Ｌ，主酵结束双乙酰为０．１３ｍｇ／Ｌ，成品啤酒双乙酰为０．０６ｍｇ／Ｌ，成品啤酒真正发酵度６５．６％，凝聚性指标Ｆ值为４８．４％，啤酒风味基本不变。     

细菌发酵生产L-乳酸培养基的优化

运用响应面分析法(中心组合设计)对干酪乳杆菌(Lactobacilluscasei)LB1 11生产L 乳酸的培养基C/N进行了研究,同时研究了有机氮源(蛋白胨、玉米浆和酵母膏)和无机氮源(NH4Cl和(NH4)2HPO4)对L 乳酸产量的影响,并进行了葡萄糖、蛋白胨、NH4Cl和(NH4)2HPO4四因素的响应面分析实验.结果表明,适宜的培养基C/N(质量比)为12∶1～13∶1,培养基组成:葡萄糖120.13g/L,蛋白胨19.342g/L,NH4Cl4g/L,(NH4)2HPO42.010g/L,L 乳酸产量可达到103g/L.优化后的培养基适合于对干酪乳杆菌进行代谢网络分析.     

乳酸对成骨样细胞成骨表型及碱性磷酸酶基因表达的影响研究

目的 明确聚乳酸降解终产物乳酸对细胞成骨表型和基因表达的影响机理，为聚乳酸支架的精确设计提供参考意义。方法 配制乳酸浓度为8、16、22、27 mmol/L的培养基，将不含乳酸培养基作为对照组，检测培养基的pH和渗透压。利用培养基培养大鼠成骨样细胞Ros17/2.8，观察细胞形态，测定细胞I型胶原、碱性磷酸酶（alkaline phosphatase，ALP）活性和骨钙素含量，盐酸四环素染色钙结节并定量分析。采用实时定量PCR法检测细胞ALP mRNA表达。结果 与对照组相比，随着乳酸浓度增加，培养基pH下降，渗透压升高，成骨样细胞形态改变，数量减少。低浓度乳酸组（8、16 mmol/L）的I型胶原量都显著高于对照组，其余组与对照组相比无显著差异。含乳酸组的细胞ALP活性都低于对照组，并且乳酸浓度越高，细胞ALP活性越低。含乳酸组的骨钙素量与对照组之间没有显著差异。随着乳酸浓度增加，含乳酸组细胞所形成的钙结节阳性面积减少，都低于对照组。低浓度乳酸组（8、16 mmol/L）的细胞ALP mRNA表达量都低于对照组。结论 聚乳酸降解终产物乳酸可抑制细胞ALP mRNA的表达，降低ALP活性。随着乳酸浓度增加，乳酸抑制作用增强，最终降低细胞的成骨矿化能力。此外，乳酸不会抑制细胞分泌I型胶原和骨钙素。     

浸入式折光计测定啤酒原麦汁浓度

本文叙述用浸入式折光计测定啤酒的原麦汁浓度具有快速、准确、连续测定的优点。通过实例,对折光法与蒸馏法进行了比较。     

L-丝氨酸产生菌的分离筛选及发酵条件

在含50mL／L的甲醇、5g／L的甘氨酸的基本培养基平板上，从土壤中分离出130多株细菌，测定了它们利用甘氨酸生产L-丝氨酸的能力，获得了一株产L-丝氨酸较好的菌株A3，L-丝氨酸产量最高为1．4g／L，分类学鉴定为微球菌科(Micrococcaceae)，对菌株A3利用甘氨酸发酵生产L-丝氨酸的发酵条件进行了初步研究，包括甘氨酸和甲醇添加量，不同碳源、氮源，初始pH值以及发酵时间对产酸的影响．结果表明，菌株A3在不添加甲醇、只以甘氨酸为惟一碳源的发酵培养基中也能产L-丝氨酸，培养基中较高质量浓度的甘氨酸存在对L-丝氨酸生产是必需的．添加葡萄糖、甘油等外源碳源对菌体生长有利但不利于L-丝氨酸的生产。     

聚左旋乳酸在皮肤紧致的应用及研究进展

聚左旋乳酸是一种生物相容性较好的可降解高分子材料，近年来在医疗行业中应用价值较高， 因其具有的无毒、无刺激且可塑性较高等特点在医美领域应用应用广泛。因此，本文通过查阅和整理相关 文献，对聚左旋乳酸对皮肤紧致的作用机制、使用方法及当前应用现状和前景进行综述，以阐明聚左旋乳 酸在皮肤紧致的应用概况，旨在为聚左旋乳酸在皮肤紧致的临床应用提供参考。     

红曲霉菌9903发酵工艺条件对色素及桔霉素生产的影响

筛选到一株高产色素、低产桔霉素的红曲霉菌9903，并鉴定该菌种为红曲红曲菌。为提高色素含量、降低桔霉素含量，对该菌的发酵培养基成分进行了研究，通过三因素三水平正交实验得到了摇瓶最佳培养基配方，在10L的自动发酵罐实验中，以玉米淀粉和谷氨酸单钠盐为主要成分的发酵液色价达到184U／mL，桔霉素质量浓度低于1mg/L，发酵动力学的初步研究表明，色素及桔霉素的生产与菌体生长有一定的偶联关系，而且桔霉素在发酵后期有一定程度的降解。此外，溶氧条件对红曲霉产色素和桔霉素的影响的初步研究表明，高溶氧对色素和桔霉素的生产都有促进作用。     

啤酒多酚物质对啤酒风味稳定性的影响

多酚是啤酒中重要的风味物质，对啤酒质量（非生物稳定性、风味稳定性以及口味）有着重要的影响。作者分析了啤酒中多酚物质的来源以及对啤酒风味稳定性的影响，并利用高效液相色谱测定了啤酒多酚中的单酚物质，研究发现其中的（＋）-儿茶素、（-）-表儿茶素、阿魏酸和槲皮素等单酚具有较高的抗氧化能力。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.