Effect of feeding fermentable fiber on synthesis of total and mucosal protein in the intestine of the growing pig

In a previous study, a reduced efficiency of ileal digestible threonine (THR) use for body protein deposition was observed in growing pigs when pectin was included in the diet. This response was not due to increased physical endogenous ileal THR loss. Our aim was to explore the contribution of diet-induced increases in protein synthesis in the colon, especially mucins, to dietary THR requirements. Twelve barrows (21 kg mean BW) were fed either a cornstarch–soybean meal-based diet (Control) or Control with 12% pectin (Pectin). Pigs were given intravenously 1.5 mmol/kg BW of L-1-¹³C valine (40 mol%) to measure fractional and absolute synthesis rates (FSR, ASR, respectively) of mucosal and whole intestinal protein in the jejunum and colon. Dietary pectin inclusion increased plasma levels of glucose, isoleucine and glutamine (P < 0.05) but had no effect on insulin or urea nitrogen (P > 0.10). There were no differences in FSR and ASR of whole intestinal protein in jejunum and colon (P > 0.10). The FSR of mucosal proteins in colon, not in jejunum, was increased with dietary pectin supplementation (P < 0.05). Assuming mucosal protein mass is constant, these results imply that the higher protein synthesis in colon mucosa contributes to the reduced THR efficiency observed in pectin-supplemented diet.     

茄子种子萌发过程中表皮粘膜对种子萌发的影响

通过对六叶茄和中长1号种子吸水率的测定,不同水分梯度种子萌发试验,不同发芽床种子萌发试验,垂直板种子萌发试验以及种子萌发过程中产生的表皮粘膜提取液处理,结果表明,粘膜不阻碍水分进入种子内部;随着种子表皮多余水分的增加,粘膜增厚,种子发芽率降低;以砂床作发芽床,种子不易产生粘膜,发芽率较高。     

The immune modifying effects of amino acids on gut-associated lymphoid tissue

The intestine and the gut-associated lymphoid tissue（GALT） are essential components of whole body immune defense,protecting the body from foreign antigens and pathogens,while allowing tolerance to commensal bacteria and dietary antigens.The requirement for protein to support the immune system is well established.Less is known regarding the immune modifying properties of individual amino acids,particularly on the GALT.Both oral and parenteral feeding studies have established convincing evidence that not only the total protein intake,but the availability of specific dietary amino acids（in particular glutamine,glutamate,and arginine,and perhaps methionine,cysteine and threonine） are essential to optimizing the immune functions of the intestine and the proximal resident immune cells.These amino acids each have unique properties that include,maintaining the integrity,growth and function of the intestine,as well as normalizing inflammatory cytokine secretion and improving T-lymphocyte numbers,specific T cell functions,and the secretion of IgA by lamina propria cells.Our understanding of this area has come from studies that have supplemented single amino acids to a mixed protein diet and measuring the effect on specific immune parameters.Future studies should be designed using amino acid mixtures that target a number of specific functions of GALT in order to optimize immune function in domestic animals and humans during critical periods of development and various disease states.     

The immune modifying effects of amino acids on gut-associated lymphoid tissue

The intestine and the gut-associated lymphoid tissue (GALT) are essential components of whole body immune defense, protecting the body from foreign antigens and pathogens, while allowing tolerance to commensal bacteria and dietary antigens. The requirement for protein to support the immune system is well established. Less is known regarding the immune modifying properties of individual amino acids, particularly on the GALT. Both oral and parenteral feeding studies have established convincing evidence that not only the total protein intake, but the availability of specific dietary amino acids (in particular glutamine, glutamate, and arginine, and perhaps methionine, cysteine and threonine) are essential to optimizing the immune functions of the intestine and the proximal resident immune cells. These amino acids each have unique properties that include, maintaining the integrity, growth and function of the intestine, as well as normalizing inflammatory cytokine secretion and improving T-lymphocyte numbers, specific T cell functions, and the secretion of IgA by lamina propria cells. Our understanding of this area has come from studies that have supplemented single amino acids to a mixed protein diet and measuring the effect on specific immune parameters. Future studies should be designed using amino acid mixtures that target a number of specific functions of GALT in order to optimize immune function in domestic animals and humans during critical periods of development and various disease states.     

51Cr-EDTA absorption blood test: an easy method for assessing small intestinal permeability in dogs

The 51Cr-EDTA test is a valuable clinical tool for screening intestinal diseases in dogs. The test is performed by calculating the percentage of recovery from urine of a PO-ingested dose of 51Cr-EDTA after 6 or 24 hours. Careful urine collection is a practical limitation of this test in dogs, and our goal was to develop a simpler test that measures 51Cr-EDTA in blood. A 51Cr-EDTA absorption test was simultaneously performed on urine and serum 43 times in healthy Beagle Dogs. Timed blood samples were withdrawn, and urine was collected during a 6-hour period. Percentages of the ingested dose were then calculated in urine and serum. The mean +/- standard deviation (range) percentage in urine after 6 hours was 14.07 +/- 8.72% (3.81-34.18%), whereas results in serum from samples taken at 2, 3, 4, 5, and 6 hours were 0.49 +/- 0.45% (0.02-2.13%), 0.75 +/- 0.52% (0.03-1.89%), 0.82 +/- 0.57% (0.13-2.21%), 0.70 +/- 0.53% (0.12-1.99%), and 0.47 +/- 0.44% (0.11-1.79%), respectively. The results for blood specimens showed good concordance with those for urine, especially for the samples taken at 4 hours (r = 0.89). Moreover, the correlation between urine and blood was better when the sum of the percentages of the recovered analyte from various blood samples was compared with urine. The correlation coefficient when summing 4 blood samples was excellent (r = 0.97) and remained excellent when summing only 2 blood samples taken at 3 and 5 hours (r = 0.95) or at 3 and 4 hours (r = 0.94). We conclude that a serum 51Cr-EDTA test determined by summing successive blood samples provides an easier means of estimating small intestinal permeability in dogs and gives results comparable to those of the 6-hour urine test.     

Nasal and frontal sinus mucosa of the adult dog contain numerous olfactory sensory neurons and ensheathing glia

Olfactory glial cells have been the focus of much recent research interest because of their possible future use as cellular transplants in repair of spinal cord injury. Although olfactory glial cells can be collected from the olfactory bulb for in vitro culture, alternative sites would be preferable for safer surgical access. This study was designed to investigate the distribution of olfactory sensory neurons and olfactory glial cells within the canine peripheral olfactory system. Using immunohistochemistry and electron microscopy on perfused tissue we demonstrate that olfactory sensory neurons are found in both the caudal nasal and the frontal sinus epithelia. Olfactory ensheathing glia were found in the mucosa at both these sites implying that surgical access for harvesting cells for transplantation would be straightforward.     

c-Fos参与羊驼小肠黏膜淋巴细胞生发中心的调控

【目的】研究转录因子c-Fos与凋亡相关蛋白Caspase3在羊驼小肠黏膜淋巴组织的表达,探索c-Fos与羊驼小肠黏膜淋巴细胞生发中心的关系。【方法】用免疫组织化学技术研究c-Fos蛋白与Caspase3蛋白在羊驼十二指肠和空肠淋巴组织的表达。【结果】免疫组织化学结果显示羊驼十二指肠黏膜淋巴细胞较少,c-Fos蛋白主要表达于空肠黏膜下淋巴组织生发中心,在黏膜下淋巴组织向固有层淋巴组织过渡区域有散在表达,在固有层弥散淋巴组织中c-Fos阳性表达细胞较少。Caspase3蛋白主要表达于空肠黏膜固有层淋巴组织,在黏膜下淋巴组织生发中心很少表达,在黏膜下淋巴组织向固有层弥散淋巴组织过渡区域Caspase3有散在表达。【结论】c-Fos参与羊驼空肠黏膜下淋巴组织生发中心增殖与分化的调控。     

外源核苷酸对断奶仔猪内脏器官重量、血清指标及空肠黏膜二糖酶活性的影响

选用21±2日龄断奶仔猪160头,随机分为2组,每组设4个重复。对照组饲喂基础日粮,试验组在基础日粮中添加0.2%核苷酸,饲养期21 d。研究外源核苷酸对断奶仔猪内脏器官重、血清指标和空肠黏膜二糖酶活性的影响。结果表明:日粮中添加核苷酸可显著提高仔猪断奶后第7 d胰腺率(P<0.05),并具有提高仔猪断奶后第14 d肝脏指数、脾脏指数趋势(P>0.05);可极显著提高仔猪断奶后第21 d血清总蛋白和血清白蛋白(P<0.01);并可显著提高仔猪断奶后第14 d空肠粘膜蔗糖酶活性(P<0.05)。     

Relationship of equine housing to large airway inflammation

The pasture, as compared to stall confinement, has been considered a more desirable environment for maintaining the health of the respiratory system in the horse. This conclusion is based on reports which showed that ventilation in most barns was generally poor, and that horses bedded on straw and fed hay were exposed to many forms of respirable debris. In this study, six normal horses were evaluated for evidence of airway mucosal inflammation after being housed on pasture or stabled in a barn for one month. The response of the horses' airways was measured by assigning scores for the degree of tracheal mucosal secretions that were observed by endoscopic visualization. Cytological examination of transtracheal wash secretions was also performed, as well as histologic evaluation of tracheobronchial tissues obtained by a transendoscopic epithelial biopsy technique. Samples were collected at three time points; the initial collection occurred after the horses were housed on pasture for one month. The horses were subsequently moved to a barn for an equal length of time and samples were obtained at the end of this period. The horses were then returned to their original pasture and final sampling was performed after they were housed in this environment for two months. There were no significant changes in any of the parameters evaluated, regardless of the environment in which the horses were maintained. These findings indicate that housing horses in a barn for four weeks does not cause tracheobronchial mucosal inflammation in a manner that could be detected using the methods employed in this study.     

禽类的结膜结合淋巴组织及其研究进展

对禽类的结膜结合淋巴组织的形态、结构、功能、发育、当前研究现况及研究动态作了较的综述。