舒巴坦、利血平、乙二胺四乙酸二钠对鸭源大肠杆菌抗菌药物敏感性的影响

本试验旨在研究β-内酰胺酶抑制剂舒巴坦、外排泵抑制剂利血平及膜通透促进剂乙二胺四乙酸二钠(EDTA)对鸭源大肠杆菌抗菌药物敏感性的影响。采用微量肉汤稀释法测定8株多重耐药鸭源大肠杆菌对头孢噻呋钠、恩诺沙星、阿米卡星、氟苯尼考、多西环素及其与舒巴坦、利血平和EDTA联用的最小抑菌浓度(MIC)。结果表明,舒巴坦能使5株鸭源大肠杆菌对头孢噻呋钠的MIC值下降4倍以上;利血平仅能使3株菌株对头孢噻呋钠的MIC值下降4倍以上;而EDTA能使7、5、3、6、8株菌对以上5种药物的MIC下降4倍以上;舒巴坦+利血平使4株菌株对头孢噻呋钠的MIC下降4倍以上,使5株菌株对氟苯尼考的MIC下降4倍以上;舒巴坦+EDTA使鸭源大肠杆菌对以上5类药物的MIC大幅度下降,分别使8、5、2、8、8株菌MIC下降4倍以上;利血平+EDTA使7株菌株对恩诺沙星MIC下降4倍以上,使所有分离株对其余4种药物的MIC显著下降;舒巴坦+利血平+EDTA和5类药物联用后,所用分离株的MIC下降4倍以上。由此可见,引起鸭源大肠杆菌对以上抗菌药物的耐药原因主要包括细胞膜通透性的下降、药物的主动外排作用和产生β-内酰胺酶的破坏作用,三者相协同提高了鸭源大肠杆菌的耐药水平。     

Physicochemical characteristics of flours of faba bean as influenced by processing methods

Wet- and dry-processing with and without heating treatments were used to dehull faba beans for preparation of flours from the cotyledons. Flour qualities were assessed by levels of tannin and trypsin inhibitor and other measures of proximate composition. High roasting temperature and shorter process time that improved the recovered cotyledon yields were verified significant by path analysis methodologies. In turn, the higher cotyledon recoveries correlated with higher protein levels and inversely with the measured tannin levels. Ash reductions were correlated to the wet processing options in hull removal while reductions in the insoluble dietary fiber were notably influenced by level of heating temperatures applied. Trypsin inhibitor levels ranged from 42 to 56% of the original with reductions tied to applications of wet and/or heat processing in each case improved by increased durations and temperatures of treatments.     

Inactivation of trypsin inhibitors in sweet potato and taro tubers during processing

In order to understand the extent of elimination of trypsininhibitors during processing of sweet potato (Ipomoea batatas) andtaro (Colocasia esculenta) tubers, a detailed study was conductedusing tubers processed by oven drying, cooking, and microwavebaking. Between 80 and 90% trypsin inhibitor (TI) activity wasretained in sweet potato chips up to 2h at 70 ^°C. Among thefour cultivars of sweet potatoes, RS-III-2 trypsin inhibitors were more heatlabile. Heating at 100 ^°C led to rapid inactivation of TI of sweetpotatoes. Varietal differences in thermal stability were more pronouncedfor the trypsin inhibitors of taro than sweet potatoes. Taro inhibitors werealso more rapidly inactivated than sweet potato TI. Between 17 and31% TI activity was retained in cooked tuber pieces of sweet potatoes,while only 3–10% were retained in taro cultivars. Very effectiveinactivation of trypsin inhibitors of sweet potatoes and taro could beobtained through microwave baking. Flour prepared from taro was devoidof TI activity, while 5–12% TI activity was retained in the flour preparedfrom sweet potatoes. The study clearly established that among the fourtechniques used, microwave baking and flour preparation were the best methods to eliminate TI from sweet potatoes and taro.     

Studies on protein quality of green gram (Phaseolus aureus)

Raw green gram contains trypsin inhibitor (5.6 × 10^–3 units/0.1 g) while cooking destroyed the trypsin inhibitor in green gram. No destruction was observed in the case of lysine, methionine, cystine, threonine and tryptophan. Sulphur containing amino acids have been found to be the only limiting amino acids in green gram from studies on blood levels of amino acids and PER experiments. Raw green gram, when fed as a sole source of protein promoted an extremely low growth rate, (13.2 g/4 weeks) and PER (0.77) in rats. Cooking slightly improved the nutritive value of the gram, as indicated by increase in gain in body weight (24 g/4 weeks) as well as PER (1.22). The presence of inhibitors in green gram did not appear to affect some of the essential amino acids as observed from the blood amino acid levels.     

The USDA trypsin inhibitor study. I. Background,objectives, and procedural details

Short-term feeding studies have shown that raw soy flour and purified trypsin inhibitors (TI) cause pancreatic hypertrophy and hyperplasia in certain monogastric animals. Prolonged exposure to high levels of TI in raw soy ultimately leads to pancreatic nodular hyperplasia and acinar cell adenoma in rats exposed to low levels of pancreatic carcinogens. Such change has been observed even in the absence of any exposure to known carcinogens. These results emphasized the need for chronic (2 yr) feeding trials which would clearly reveal dose response relationships of alterations in pancreatic pathology to dietary TI and possible interactions with dietary protein and fat.Here we report on the objectives and designs of the first phase of the USDA TI Study, including composition of diets, preparation, and analyses of test substances. To provide the requisite TI and protein levels, raw and heated defatted soy flours, soy protein isolates, and lactic casein were used. The interrelationship of dietary level of TI (93–1270 mg/100 g diet) and that of protein (10%, 20%, and 30%) to pancreatic function and pathology will be reported in the following three papers. Both serial and chronic sacrifice regimes, respectively, were employed with 26 diets and 40 weaning male Wistar rats per dietary group.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Anti-nutritional and toxic factors in food legumes: a review

A comprehensive review on the presence of certain important anti-nutritional and toxic factors in food legumes has been conducted. These substances include proteolytic inhibitors, phytohemagglutinins, lathyrogens, cyanogenetic compounds, compounds causing favism, factors affecting digestibility and saponins. These factors are shown to be widely present in leguminous foods which are important constituents of the diet of a large section of the world's population, and particularly, of people in the developing countries.     

信号转导抑制剂对囊素刺激杂交瘤细胞抗体分泌及其mRNA表达的影响

以杂交瘤细胞为模型 ,在培养液中加入不同的信号转导抑制剂和囊素 ,用间接ELISA法测定抗体分泌水平 ,用定量RT PCR法检测抗体mRNA的表达水平。结果表明 ,加入Gα 蛋白选择性抑制剂NF 0 2 3、蛋白激酶C抑制剂GF10 92 0 3X、磷脂酰肌醇 3激酶抑制剂heparin、Ca2 /calmodulin依赖蛋白激酶Ⅱ抑制剂KN 6 2、磷脂酶C抑制剂U 7312 2和蛋白激酶G抑制剂后 ,囊素对杂交瘤细胞抗体分泌速度的影响明显 (P <0 0 1)。而加入蛋白激酶A抑制剂 4 Cyano 3 M thylisoquinoline、酪氨酸蛋白激酶抑制剂 genistein和丝裂原活化的蛋白激酶抑制剂PD 980 5 9后 ,囊素对杂交瘤细胞抗体分泌速度的影响不明显 (P >0 0 5 ) ,这 3种抑制剂对杂交瘤细胞抗体分泌速度的抑制率分别为 74 5 5 % ,91 13%和80 6 9%。加入 4 Cyano 3 M thylisoquinoline、genistein和PD 980 5 9后 ,囊素处理组与对照组γ1mRNA的表达水平差异不显著 (P >0 0 5 ) ,说明这 3种抑制剂阻断了囊素刺激的杂交瘤细胞抗体mRNA的表达。以上结果表明 ,蛋白激酶A、酪氨酸蛋白激酶和丝裂原活化的蛋白激酶参与了囊素在杂交瘤细胞中的信号转导。     

EFFECT OF NEEM-OIL COATED PRILLED UREA WITH VARYING THICKNESS OF NEEM-OIL COATING AND NITROGEN RATES ON PRODUCTIVITY AND NITROGEN-USE EFFICIENCY OF LOWLAND IRRIGATED RICE UNDER INDO-GANGETIC PLAINS

The nitrogen (N) fertilizer-use efficiency (20–50%) is low in rice fields in India. The neem-oil coated urea can increase N-use efficiency in lowland rice, but the desirable thickness of neem-oil coating onto urea is not known yet. Therefore, field experiments were conducted during kharif (rainy) season years 2004 and 2005 at the Research Farm of Indian Agricultural Research Institute, New Delhi to know the suitable thickness of neem-oil coating on prilled urea (PU) for increased N-use efficiency and yield. The treatments comprised of twelve combinations of four N sources (PU coated with neem-oil thickness of 0, 500, 1000 and 2000 mg kg^?1 PU) and three N levels (50, 100, and 150 kg N ha^?1) plus a no-N control. Prilled urea (PU) refers to the common urea available commercially in prills, which is different from urea super granules. Application of urea coated with neem-oil thickness of 1000 mg kg^?1 PU resulted in significantly higher growth, yield parameters, grain yield, N uptake, and efficiency of aromatic rice (Oryza sativa L.) over uncoated PU. Nitrogen application at 122 kg ha^?1 was optimum for increased yield of rice. Nitrogen-use efficiency decreased significantly and substantially with each successive increase in levels of N from 50 to 150 kg ha^?1.     

黑龙江省稻稗对丁草胺的抗性测定及交互抗性的研究

【目的】明确黑龙江省水田稻稗(Echinochloa oryzicola Vasing)对丁草胺的抗药性水平以及对其他细胞分裂抑制剂的交互抗药性水平。【方法】采用琼脂法和整株盆栽法测定了黑龙江省14个地区53个田块的稻稗对丁草胺的抗药性以及对其他3种细胞分裂抑制剂丙草胺、苯噻酰草胺和莎稗磷的交互抗性。【结果】琼脂法检测出庆安03、东京城镇02等4个稻稗生物型对丁草胺产生了中等水平抗性，抗性指数为12.92~26.03，占供试稻稗生物型的7.55%；兴隆镇03、阿城04等4个稻稗生物型对丁草胺产生了低等水平抗性，抗性指数为6.63~8.86，占供试稻稗生物型的7.55%；庆安01、汤原01等5个稻稗生物型对丁草胺敏感性下降，抗性指数为3.18~4.84，占供试稻稗生物型的9.43%；其余阿城02、尚志02等40个稻稗生物型对丁草胺表现敏感，抗性指数均小于3，占供试稻稗生物型的75.47%。选取上述测定结果当中抗性最高的两个生物型，使用整株盆栽法进行对丁草胺的抗性水平验证。发现庆安03和东京城镇02同样产生了中等水平抗性，抗性指数分别为16.78和13.27；同时测定两个抗性生物型对丙草胺、苯噻酰草胺和莎稗磷3种细胞分裂抑制剂的交互抗性，结果显示，庆安03稻稗生物型对丁草胺和丙草胺产生了交互抗性；东京城镇02稻稗生物型对丁草胺、丙草胺和莎稗磷产生了交互抗性。【结论】黑龙江省部分地区稻稗对丁草胺产生了抗药性，且对丙草胺和莎稗磷产生了交互抗性。     

Effect of cooking on proteinase inhibitors ofDolichos lablab bean (Dolichos lablab perpureus L.)

Proteinase inhibitory activity in ten different varieties ofDolichos lablab perpureus. L. was determined. All the varieties tested exhibited appreciable level of proteinase inhibitory activity (PIA). The trypsin inhibitory activity (TIA) (Mean:20170 TIU/g) was relatively higher than the chymotrypsin inhibitory activity (CIA) (Mean: 15380 CIU/g). Effect of temperature and cooking on PIA was studied. The nature of cooking medium and duration of cooking had profound effect on the PIA. The dry fried seeds lost their PIA very rapidly (91% in 20 min). Seeds cooked in slightly alkaline medium lost their PIA quickly (89% in 30 min) compared to those cooked in acidic (80% in 30 min) and neutral pH (83% in 30 min). The PIA in green pods was also determined and they had only one third of the PIA (8200 TIU/g and 8125 CIU/g) found in the dry seeds.