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91.
We conducted a study to determine the effects of treating barley grain with a fibrolytic enzyme mixture on chewing activities, ruminal fermentation, and total tract digestibility in cattle. We also investigated the potential benefits of using barley straw rather than barley silage as a roughage source in high-grain diets for feedlot cattle. Steers were given ad libitum access to one of four diets that consisted of 95% barley-based concentrate and 5% forage (DM basis). The concentrate was either control or enzyme-treated, and the forage was either barley silage or barley straw. Applying the enzyme mixture onto the barley lowered the concentrations of dietary ADF and NDF. However, it is not certain when this fiber hydrolysis occurred relative to feed consumption because the fiber analyses were conducted after the study was completed. Enzyme treatment of barley increased total tract dietary ADF digestibility by 28% (P<.05). Acetate-to-propionate ratio tended to decrease, which suggests that enzymes may have increased ruminal starch digestion as a result of enhanced digestion of barley hulls. Replacing silage with straw increased ADF intake (P<.05) and resulted in 1-h/d increase in rumination time (P<.05). Even though there was no effect of diet on ruminal pH, replacing silage with straw increased ruminal acetate, as a percentage of total VFA, and total tract ADF digestion (P<.01). This study demonstrates that using a fibrolytic enzyme mixture in high-grain diets that contain mainly barley grain can improve fiber digestion and grain utilization, but the mode of action is unclear. Straw can be used rather than silage to increase the effective fiber content of a high-grain feedlot diet.  相似文献   
92.
A 13-year-old girl underwent a right salpingo-o-ophorectomy and partial omentectomy for an ovarian tumor that on microscopic examination was a grade 1 immature teratoma. Mature glial implants were found in the omentum (Stage III). No additional treatment was given. Ten months later, grade 0 and grade 1 peritoneal glial implants were found on laparotomy. Chemotherapy with four cycles of vincristine/cisplatin/etoposide/bleomycin was administered. A second laparotomy 4 months later showed persistence of grade 0 and grade 1 peritoneal glial implants. The patient was well for the next 7 years, after which time she presented with a pelvic mass that on microscopic examination was a malignant neuroectodermal tumor resembling a glioblastoma multiforme. The tumor did not respond to debulking and chemotherapy, and the patient died 6 months later, 8 years after her initial presentation. This case represents the second report of malignant transformation of peritoneal glial implants.  相似文献   
93.
Selenium is a trace element which plays a vital role in many metabolic functions and in particular is an integral part of the antioxidant enzyme glutathione peroxidase. It may be involved in the prevention of a number of diseases including cardiovascular diseases and cancer, which are the main causes of death in Singapore with ethnic differences. The National University of Singapore Heart Study measured cardiovascular risk factors, including serum selenium, in a random of the general population aged 30 to 69 years from 1993 to 1995. Mean serum selenium was higher in Chinese (males 126 and females 119 micrograms/L) and Malays (males 122 and females 122 micrograms/L) than Indians (males 117 and females 115 micrograms/L). These levels (with an estimated mean of 122 micrograms/L in Singapore) are lower than those in the USA but higher than those in Western Europe. The proportions with serum selenium < 80 micrograms/L (classified as low values) were low, though highest in Indians (males 1.2% and females 1.2%), then Chinese (males 0.6% and females 1.3%) and then Malays (males 0.0% and females 0.0%), but the differences were not statistically significant. The overall estimate for the prevalence of low selenium in Singapore was 0.8%. It is concluded that levels of serum selenium in Singapore are satisfactory and no action with regard to dietary supplementation is needed. Serum selenium levels are slightly lower in Indians than in Chinese and Malays (probably due to a more vegetarian diet) and this may make a small contribution to Indians' higher rates of coronary heart disease compared to Chinese and Malays.  相似文献   
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Agrobacterium sp. strain KNK712, which produced N-carbamyl-D-amino acid amidohydrolase (DCase) was isolated from soil. The bacterium had D-specific hydantoinase activity also. Both enzymes are suitable for use in the production of D-amino acids. The DCase gene from Agrobacterium sp. strain KNK712 was cloned into Escherichia coli. The cloned DNA fragment contained one open reading frame, predicted to encode a peptide of 304 amino acids, with a calculated molecular weight of 34,285. The DCase gene was overexpressed under the control of the lac promoter, and DCase accounted for 50% of the soluble protein in the cells. The enzyme was purified and some properties were investigated. Both the optimum pH and the pH that gave greatest stability were about pH 7.0. The optimum temperature was 65 degrees C, and the enzyme was stable at 55 degrees C. The enzyme had strict specificity toward N-carbamyl-D-amino acids, and was inhibited by thiol reagents, Cu2+, Hg2+, Ag+, and ammonia.  相似文献   
96.
BACKGROUND: Total parenteral nutrition (TPN) alters both specific and nonspecific immune functions, resulting in immunosuppression. Short-chain fatty acids have been shown to improve the adaptive responses of the gut after surgery. The following study investigates the effects of adding short-chain fatty acids to TPN on the immune system after an 80% small bowel resection. METHODS: Rats (237 +/- 3 g) were infused with either TPN (n = 25) or TPN supplemented with short-chain fatty acids (n = 26) for 3 or 7 days. Hematologic analysis was performed on peripheral blood and splenocytes were isolated to characterize cell phenotypes, natural killer cell cytotoxicity and to estimate proliferative response. RESULTS: The relative percent of T (CD3+) cells increased (p < .05) and the relative percent of macrophages decreased (p < .001, n = 13) in the spleens of the 3-day TPN-fed rats. By day 7, these differences disappeared. The natural killer cells from rats that were supplemented with short-chain fatty acids had higher (p < .0001) cytotoxic activity than the TPN groups at day 3. Mitogenic response did not differ between groups but were depressed compared with sham-treated rats. By day 7, rats on standard TPN had larger (p < .0001) spleens than all other groups. This group also had a higher total white blood cell count because of increased numbers of macrophages and neutrophils (p < .02). CONCLUSION: Short-chain fatty acids improve components of nonspecific immune responses and may be beneficial in reducing certain aspects of TPN-associated immunosuppression after major surgery.  相似文献   
97.
Fibro-osseous lesions of the sinonasal region are relatively frequent, but those strictly confined to the nasal cavity are rare. We report an atypical fibro-osseous lesion in the nasal cavity and describe its radiological features. The differential diagnosis is discussed.  相似文献   
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99.
OBJECTIVES: Cardioprotective adaptation to brief periods of ischemia and reperfusion is termed ischemic preconditioning (PC). Limitation of infarct size by preconditioning is associated with marked slowing of ischemic metabolism. The cause of metabolic slowing has not been determined but may involve either pro- or anti-adrenergic mechanisms. Hypothetically, adrenergic stimulation could signal the adaptive response. Alternatively, metabolic slowing during the sustained ischemic challenge could occur through a reduction in beta-adrenergic stimulation. This study was designed to test the role of cardiac norepinephrine (NE) in PC. METHODS: The effect of PC on myocardial infarct size was studied in control dogs and dogs depleted of catecholamines by pretreatment with reserpine (RES; 0.25 mg/kg i.v.). PC was induced by four cycles of 5 min of ischemia and 5 min of reperfusion. Infarcts were produced by 60 min of ischemia and 3 h of reperfusion. Cardiac NE depletion was verified by radioimmunoassay of tissue samples and by absence of hemodynamic response to a tyramine bolus (1.4 mg/kg) administered at the end of each experiment. Infarct size, expressed as percent of area at risk, was controlled for variation in collateral blood flow using analysis of covariance (ANCOVA). RESULTS: Adjusted mean infarct size was 25.5 +/- 3.2% in untreated controls vs. 19.1 +/- 3.3% in RES-treated controls (P = NS). PC limited infarct size in untreated dogs (7.4 +/- 1.8 vs. 25.5 +/- 3.2%; PC vs. control; P < 0.01) but not in RES-treated dogs (15.7 +/- 3.0% vs. 19.1 +/- 3.3%; RES + PC vs. RES; P = NS). Infarct size was larger in dogs with RES + PC than with PC alone, even though there was a trend toward a slight beneficial effect with RES alone. CONCLUSION: The cardioprotective effect of ischemic preconditioning cannot be explained entirely as an anti-adrenergic effect. On the contrary, adrenergic receptor stimulation may be required for the full expression of ischemic preconditioning in canine myocardium.  相似文献   
100.
The impact of pregnancy and food intake on plasma leptin levels was investigated in insulin-dependent diabetes mellitus (IDDM) patients and healthy normal-weight women. Fourteen women with IDDM and 11 women with no diabetes or family history of diabetes were served a 707-kcal lunch in gestational weeks 34 to 38. Six breast-feeding women from each group were examined a second time within 1 month after delivery. Leptin levels were not different in the two groups either during pregnancy or postpartum. In addition to a positive correlation to body mass index (BMI), leptin levels tended to correlate with gestational weight gain. The leptin concentration during pregnancy was higher than the postpartum level, which was within the range of previously reported levels in non-obese nonpregnant women. Ingestion of the test meal did not affect leptin levels and there were no relationships between leptin and insulin or glucose, for either basal or postprandial (60-minute) levels. Only the insulin dose taken by the diabetic women correlated to leptin level. During pregnancy, there is an augmented energy expenditure and maternal metabolism is altered to increase fat stores. The present observation that leptin levels were elevated in pregnant women suggests an additional role for leptin in the accumulation of body fat.  相似文献   
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