麦苗粉的微波杀菌

研究了微波功率、杀菌时间、物料量对麦苗粉杀菌效果的影响,在此基础上,以菌落总数和a*值为考察指标,采用正交试验进一步优化了麦苗粉微波杀菌的最佳条件,并与常规加热杀菌方法相比较;分析了麦苗粉杀菌前及经过最优工艺微波杀菌后的品质变化.结果表明,微波功率、杀菌时间对杀菌效果有重要影响,试验所得的麦苗粉最佳微波杀菌工艺为:微波功率510 W,时间120 s,物料用量12 g.与常规加热处理相比,麦苗粉采用微波杀菌不仅能达到较好的杀菌效果,而且品质保持良好.微波杀菌后麦苗粉的外观、色泽变化小;水分、灰分、总糖等理化指标基本不发生变化;叶绿素、维生素C等营养成分损失少.     

油豆腐软罐头杀菌工艺试验

油豆腐是一种营养丰富的豆制品,由于含有较高的蛋白质和脂肪,其产品不易保存.将油豆腐制成软罐头的形式,既能延长其保质期,又便于食用.试验用高温高压杀菌锅对油豆腐软罐头进行杀菌研究,确定其最佳杀菌工艺为120℃条件下9min-25min-10min.在该杀菌工艺条件,油豆腐中微生物指标达到软罐头产品质量标准,油豆腐软罐头能保存半年以上时间.     

FD蔬菜块中大肠杆菌的分离及其失活条件

通过选择性培养基将大肠杆菌从FD蔬菜块中分离出来并进行菌种保存,对保存的菌种分别采用臭氧、紫外辐照、微波等杀菌手段处理,并确定最优杀菌工艺条件,以期对FD蔬菜块的微生物控制起作用.     

加热巴氏杀菌和辐射选择性杀菌联合加工对圆腿货架寿命和产品品质的影响 初报

加热巴氏杀菌后样品中的细菌总数,可用钴一60γ射线辐射杀菌的方法使之进一步降低,D_(10)=0.12Mrad。0.3Mrad辐照的样品,在0℃条件下货架寿命可达半年,比对照的延长了一倍以上。辐照对产品的化学成份没有影响。产品经品尝试验,接受情况良好。加热巴氏杀菌和辐射选择性杀菌联合加工是圆腿的一种新加工工艺。     

β-内酰胺类抗生素在胆汁中的浓度和药动学的实验研究

目的 研究β-内酰胺类抗生素在胆汁中的浓度及其药动学,并对杀菌效力进行评估,为临床上肝胆系统感染选择用药提供参考和依据.方法 家兔行胆总管造瘘术,分别静脉注射哌拉西林/他唑巴坦、头孢曲松和美罗堵南等β-内酰胺类抗生素后于不同时间收集胆汁标本,采用HPLC法测定各抗生素的浓度,并计算出药动学参数.结合最低抑菌浓度(MIC),评估抗生素在胆汁中的杀菌效力.结果 各抗生素在胆汁中的峰浓度和半衰期分别为:哌拉西林(7950.16±3023.00)μg/ml和(1.97±1.23)h,头孢曲松(1107.01±247.61)μg/ml和(3.14±0.57)h,美罗培南(31.97±12.44)μg/ml和(0.36±0.11)h.哌拉西林/他唑巴坦的杀菌指数最大、TMIC最长,对大部分胆道感染常见致病菌均可形成MIC90 100倍以上的浓度,TMIC长达6～8 h;头孢曲松和美罗培南较低.结论 哌拉西林、头孢曲松和美罗培南均可在胆汁中达到有效杀菌浓度,哌拉西林/他唑巴坦杀菌效力最强.     

菠萝果酒发酵的工艺

以菠萝全汁为原料,对菠萝果酒的加工工艺及影响菠萝果酒品质的关键性工艺参数进行了研究.按照0.025%的比例向压榨后的果汁中添加果胶酶,并保温40 ℃作用2 h后,采用正交试验法优化发酵条件,结果显示：采用一次加糖法将糖质量浓度调至每100 mL 20 g,添加柠檬酸至pH 3.6、添加偏重亚硫酸钾至质量浓度110 mg/L、主发酵温度22 ℃,发酵7 d;后发酵温度16 ℃,发酵10 d;10 ℃陈酿2～3个月.采用明胶-丹宁复合澄清剂澄清处理,最后75 ℃,15 min杀菌后,得到果香浓郁、色泽金黄、澄清透明的优质菠萝果酒.     

FD蔬菜块后续臭氧杀菌工艺

以某公司生产的FD蔬菜块为例,将臭氧气体作为主要杀菌手段,同时辅助以紫外照射的方法,研究了杀菌过程中臭氧浓度、杀菌时间、紫外灯压等因素对杀菌效果的影响,并对杀菌处理后的产品进行了品质考察.结果表明,臭氧联合紫外辐照杀菌技术可有效杀死产品中的微生物,将产品控制在安全范围以内,且不破坏产品品质,真正做到了杀菌彻底且无残留.     

一种新型开菲尔奶制作工艺

将草莓汁、菠萝汁、白砂糖加入鲜牛奶中经杀菌冷却后接种开菲尔粒制作的发酵剂,25℃恒温发酵,采用正交试验法对其它工艺参数进行了研究.结果表明,草莓汁和菠萝汁的添加体积分数均为3%,白砂糖质量分数为8%,接种发酵剂体积分数4%,发酵16h后获得了一种口感、组织状态、风味俱佳的新型开菲尔奶.     

接种方式对阿维菌素发酵过程的影响

在摇瓶发酵中对除虫链霉菌的孢子接种工艺进行了初步研究,同时比较了孢子接种、常规的挖块接种和菌丝接种3种不同接种方式对除虫链霉菌菌体生长和细胞代谢参数的影响.实验结果表明:孢子接种的最适孢子接种量在4～6×106个/mL范围内,而不同接种方式导致了发酵过程除虫链霉菌营养物质消耗、pH值变化、菌丝形态以及效价等方面差异.孢子接种方式在摇瓶发酵中表现出明显优势,采用孢子接种方式获得最终阿维菌素的效价比常规的挖块接种方式提高10%以上,比菌丝接种方式提高了20%以上.     

抗菌药物在胆汁中药物代谢动力学特点的实验研究及杀菌效力评价

目的 探讨6种抗菌药物在胆汁中的药物代谢动力学特点,并评估其杀菌效力.方法 实验用健康家兔36只,随机分为6组,每组6只.行胆总管造瘘术后,分别静脉注射头孢曲松、头孢哌酮/舒巴坦钠、哌拉西林/他唑巴坦、美罗培南、左氧氟沙星、甲硝唑,于注射后不同时间收集家兔胆汁标本,采用高效液相色谱法测定各抗菌药物的浓度,并计算出药物代谢动力学参数.结合最低抑菌浓度(MIC)评估各抗菌药物在胆汁中的杀菌效力.结果 各抗菌药物在胆汁中的峰浓度和半衰期分别为:哌拉西林(7 950 ±3 023) mg/L和(1.97±1.23)h,头孢曲松(1 104±248) mg/L和(3.14±0.57)h,头孢哌酮(5 215 ±2 225) mg/L和(0.89 ±0.13)h,美罗培南(31.97 ±12.44) mg/L和(0.36±0.11)h,左氧氟沙星(66.3±36.9) mg/L和(3.32±2.57)h,甲硝唑(28.2±10.2) mg/L和(0.81 ±0.33)h.哌拉西林/他唑巴坦和头孢哌酮/舒巴坦的杀菌指数最大,分别为(62.1±23.6) ～(993.8±377.9)和(164.8 ±69.0) ～ (659.3 ±275.9),其药物浓度持续在MIC以上的时间(T＞MIC)最长,两药的T＞MIC分别为(6.00±2.53)～(8.00±0.00)h和(6.33±1.97) ～ (8.00±0.00)h;左氧氟沙星的杀菌指数[(2.1±1.2)～(8.3±4.6)]和T＞MIC[(0.54±0.25)～(2.67±1.03)h]最小,头孢曲松和美罗培南居中,其杀菌指数和T＞MIC分别为(4.3±1.0) ～ (69.2±15.5)、(1.42±0.65)～(8.00±0.00)h和(2.0±0.8)～(1 031.3 ±401.4)、(0.29 ±0.10) ～ (1.83 ±0.26)h.甲硝唑对厌氧菌的杀菌指数和T＞MIC分别为7.4 ～294.9和1.88 ～5.00 h.结论 6种抗菌药物均可在胆汁中达到有效杀菌浓度,哌拉西林、头孢哌酮、美罗培南、甲硝唑在家兔胆汁中呈一房室模型,头孢曲松、左氧氟沙星为二房室模型分布.哌拉西林/他唑巴坦和头孢哌酮/舒巴坦杀菌效力最强,甲硝唑对厌氧菌有较强的杀菌力,肝胆系统感染应结合临床选用杀菌效力强的抗菌药物.     

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 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.     

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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.     

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.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.