饥饿胁迫对瓦氏黄颡鱼脂肪代谢的影响

在水温(252)℃条件下, 对初始体重为(23.652.82) g的瓦氏黄颡鱼进行30d饥饿处理, 于饥饿第0、第7、第15和第30天取样, 分析了饥饿胁迫对瓦氏黄颡鱼的生长、体成分、脂肪酸组成和脂肪代谢相关基因表达的影响. 结果表明: 饥饿胁迫显著降低了瓦氏黄颡鱼肥满度、脂体比及肝体指数(p0.05). 肌肉脂肪含量也随着饥饿时间的延长而下降(p0.05). 肝脏中的饱和脂肪酸和肌肉中的单不饱和脂肪酸显著下降, 而肝脏中多不饱和脂肪酸和单不饱和脂肪酸及肌肉中的多不饱和脂肪酸显著上升(p0.05). 此外, 肌肉中的n-6和n-3及肝脏中的n-6多不饱和脂肪酸显著上升, 而肝脏中的n-3多不饱和脂肪酸显著下降(p0.05), 表明瓦氏黄颡鱼饥饿期间主要消耗饱和脂肪酸及单不饱和脂肪酸供能, 保留多不饱和脂肪酸. 饥饿胁迫15-30d, 瓦氏黄颡鱼肝脏脂蛋白酯酶、肝酯酶及肉碱酰基转运酶mRNA表达显著高于对照组(0d)(p0.05), 而脂肪酸结合蛋白及脂肪酸合成酶mRNA的表达显著低于对照组(p0.05), 表明饥饿胁迫可能会促进肝脏脂肪分解供能, 降低脂肪的生物合成.       

氧化油脂对斑点叉尾鮰生长、体色和抗氧化能力的影响

为考察正常及氧化鱼油、豆油、混合油脂(鱼油﹕豆油=1﹕1)对斑点叉尾鮰(Ictalurus punctatus)生长性能、体色和肝脏抗氧化能力的影响, 设计6组等氮等脂饲料, 分别添加6%鱼油、6%豆油、3%鱼油+3%豆油、6%氧化鱼油、6%氧化豆油、3%氧化鱼油+3%氧化豆油, 饲喂6组初始体重(150.5±4.2 g)的斑点叉尾鮰8周, 每组3个重复, 每个重复14尾鱼。结果表明, 摄食6%鱼油、6%豆油、3%鱼油+3%豆油饲料的斑点叉尾鮰在增重率、饲料系数、肌肉组成、体色和肝脏抗氧化指标上均无显著差异(P>0.05); 摄食3组氧化油脂饲料后, 鱼体增重率和肌肉粗脂肪含量降低(P<0.05), 饲料系数和背部、尾部皮肤b*(黄度值)增加(P<0.05), 肝脏丙二醛(MDA)和血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、总胆红素(TBIL)和直接胆红素升高(DBIL)(P<0.05), 肝脏超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、还原型谷胱甘肽降低(GSH)(P<0.05), 而肌肉色度值(L*、a* 、b*)和肌肉水分、粗蛋白质、灰分含量无显著差异(P>0.05)。以上结果表明, 6%氧化油脂(鱼油、豆油或混合油脂)导致斑点叉尾鮰生长性能下降、皮肤黄度增加、肝脏抗氧化能力受损; 豆油可替代斑点叉尾鮰饲料中鱼油的使用, 而不会对生长产生负面影响。     

饥饿和再喂食对泥鳅生化组成的影响

研究了泥鳅(Misgurnus anguillicaudatus)在18±0.5℃下,饥饿20 d和恢复喂食8 d的生化组成变化。结果表明,在饥饿初期,泥鳅鱼体的脂肪和蛋白质含量均明显地下降,饥饿15 d后,脂肪的降低量减少并趋于稳定,而蛋白质的含量则进一步显著降低。这表明在饥饿过程中,泥鳅首先动用机体的脂肪和蛋白质提供能源,饥饿至一定程度后则主要利用蛋白质。恢复喂食后这两种物质的含量均迅速回升,其中恢复喂食5 d后,脂肪和蛋白质的含量均达到初始水平。水分和灰分在饥饿过程中呈上升趋势,恢复后便开始下降;饥饿20 d后,鱼体的饱和脂肪酸含量基本保持不变,而多不饱和脂肪酸和单不饱和脂肪酸含量分别有一定的增加和降低,另外n-3系列脂肪酸含量升高,而n-6系列脂肪酸几乎不变。     

斑点叉尾鮰鱼油脂成分分析

采用铁锅炼制提取斑点叉尾鮰内脏鱼油,然后加酸使其甲酯化,以气相色谱/质谱法分析鱼油中的脂肪酸.结果斑点叉尾鮰内脏纯油脂中鱼油达到99%.从鱼油中共鉴定出15种成分,有饱和脂肪酸及不饱和脂肪酸,还有少量烷烃类物质.不饱和脂肪酸含量为76.40%,其中多不饱和脂肪酸为18.03%,以C18∶ 2(16.23%)为主,单不饱和脂肪酸为58.37%,以C18∶ 1(54.88%)为主.饱和脂肪酸含量为20.91%,主要有C16∶ 0 (15.84%)和C18∶ 0(4.29%),多是低于C18以上的中长链脂肪酸.因此斑点叉尾鮰油脂可作功能性脂肪酸的重要膳食来源.     

短期饥饿胁迫对鮸鱼生化组成、脂肪酸和氨基酸组成的影响

在水温(22±1)℃条件下,研究了短期饥饿胁迫对鮸鱼幼鱼生化组成、脂肪酸和氨基酸的影响。幼鱼分别饥饿0d（S0）、饥饿3d（S3）、饥饿6d（S6）、饥饿9d（S9）、饥饿12d（S12）和饥饿15d（S15）。结果表明：鱼体内的粗蛋白、粗脂肪和糖类随着饥饿时间的延长而逐渐降低,而水分和灰份随着饥饿时间的延长而逐渐升高。饱和脂肪酸（SFA）和单不饱和脂肪酸（MUFA）显著下降（p<0.05）;而多不饱和脂肪酸（PUFA）呈先上升趋势。鮸鱼幼鱼短期饥饿胁迫过程中,首先利用饱和脂肪酸,然后利用低不饱和脂肪酸,最后才动用高不饱和脂肪酸。双键位置不同的脂肪酸在饥饿过程中的损失速度也有差异,具体为n-9 PUFA＞n-6 PUFA＞n-3 PUFA。S0主要氨基酸为天冬氨酸、谷氨酸、蛋氨酸、亮氨酸、赖氨酸和精氨酸。经过不同时间饥饿后,氨基酸总量和必须氨基酸总量显著下降,与S0组均差异显著（p<0.05）,但S9、S12和S15的基酸总量和必须氨基酸总量差异性不显著（p>0.05）。     

越冬饥饿胁迫对草鱼机体生化组成和糖脂蛋白代谢相关基因转录水平的影响

为了探讨草鱼(Ctenopharyngodon idellus)在越冬期间能量利用的代谢适应机制, 将草鱼初始体重[(1053.33±16.11) g]置于室外水泥培育池, 分别在自然越冬饥饿0、1、2、4、8、12和16周后进行采样, 进行肌肉常规成分、血清能量代谢物、组织糖原、甘油三酯含量及AMP活化蛋白激酶和糖脂蛋白代谢相关基因转录水平的检测。结果显示: 越冬饥饿1周后, 草鱼肌肉各常规成分含量显著变化(P<0.05); 随着越冬饥饿时间的延长, 血清甘油三酯(TG)、甘油(Glycerol)、总蛋白(TP)、总胆固醇(TCHO)和血糖(GLU)含量先显著降低(P<0.05), 随后保持稳定, 游离脂肪酸(Free fatty acids)含量显著上升(P<0.05); 肝胰脏糖原和肌肉糖原及肝胰脏、肌肉和脂肪组织TG含量显著降低(P<0.05); 血清ATP、ADP和AMP含量显著降低, ADP+AMP/ATP比值显著升高(P<0.05); 肝胰脏、肌肉及腹腔脂肪ampk α1、ampk α2基因表达显著上升(P<0.05), 下游糖脂及蛋白代谢相关基因转录水平显著上升(包括atgl、hsl、cpt1α、cd36等脂分解相关基因; gk、pfk、pk等糖酵解相关基因; gldh、 igf-1等蛋白分解相关基因)或显著下调(acc、fas等脂合成相关基因; creb、foxo1、pgc-1α、pepck、g6pase、glut2等糖异生相关基因; tor、s6k等蛋白合成相关基因)(P<0.05)。研究表明, 草鱼在越冬饥饿期间, 血清、肝胰脏、肌肉和脂肪组织生化组成发生了上述变化的同时, 越冬饥饿胁迫激活了AMPK通路, 促进了各组织糖酵解、脂质分解、脂肪酸β氧化、脂肪酸转运及蛋白分解的进程, 抑制了糖原合成、脂质合成和蛋白合成的过程, 进而维持了机体能量稳态。     

再投喂鱼油对瓦氏黄颡鱼肌肉脂肪酸组成的影响

为研究植物油替代鱼油对瓦氏黄颡鱼（Pelteobagrus vachelli）生长及肌肉脂肪组成的影响及重投喂鱼油对瓦氏黄颡鱼肌肉脂肪酸组成的影响,实验以大豆油分别替代饲料中的0（FO）、50（S1）、75（S2）和100%（SO）的鱼油配制等氮、等能的颗粒饲料,每组设置3个平行,养殖80d后,再投喂鱼油30d。结果表明,饲料中添加豆油不会显著影响瓦氏黄颡鱼的增重率、肝体指数和体成分（P>0.05）。随着饲料中大豆油含量的增加,S2和SO组肌肉中C18:1n-9、C18:2n-6和单不饱和脂肪酸比例显著增加（P < 0.05）,而C20:5n-3,C22:5n-3及n-3/n-6比例显著下降（P < 0.05）。再投喂鱼油30d后,SO组肌肉中C18:3n-6、C20:4n-6、Σ n-9、Σ n-6和S2组中C18:1n-9、Σ n-6比例显著下降（P < 0.05）,而S2和SO组肌肉中Σn-3多不饱和脂肪酸、C20:5n-3和C22:5n-3比例显著增加（P < 0.05）。在生产中,可采用先植物油饲料、后鱼油饲料的养殖方式提高瓦氏黄颡鱼肌肉品质（增加有益人类健康的多不饱和脂肪酸）。     

斑点叉尾鮰套肠症的病原学初步研究

本研究从2例垂死的患败血症并肠套叠的斑点叉尾鮰血液、肝脏及脑组织中分离到2种类型的致病性细菌菌株,经对细菌进行形态观察、生理生化测试和16S rDNA序列分析,分别鉴定为嗜水气单胞菌和荧光假单胞菌;攻毒实验证实它们确为斑点叉尾鮰病鱼的病原。根据药敏实验的结果,及时对病区斑点叉尾鮰进行治疗,连续用药3-5天,发病的叉尾鮰即停止死亡。根据研究结果,文章对斑点叉尾鮰肠套叠发生的原因进行了的分析,提出了不同的观点。     

上市前限喂对池塘养殖异育银鲫生长及品质的影响

实验采用5种投喂水平:饱食（R100）、80%饱食（R80）、60%饱食（R60）、40%饱食（R40）、饥饿（R0）,旨在探究上市前一个月的池塘养殖中,采用不同程度限喂的投喂策略对异育银鲫生长和品质的影响。结果表明,当投喂水平小于60%,特定生长率（SGR）显著下降,而屠宰率则表现出相反趋势。饥饿组实验鱼呈现出较瘦体形和较硬的肌肉质地。对可能影响肌肉质地的脂肪含量和胶原蛋白总量分析发现,随着投喂水平的降低肌肉脂肪含量显著减少但胶原蛋白总量无显著差异。投喂水平的降低导致鱼体各组织脂肪含量的降低,尤其是内脏脂肪的显著减少。通过SGR与脂肪含量的线性模型,SGR分别解释背肌、腹肌、内脏脂肪含量总变化的56%、66%、71%。在各投喂水平条件下肌肉的粗蛋白含量和必需氨基酸与非必需氨基酸之比维持相对稳定,表明在上市前一个月的池塘养殖中,限喂的方式并未对肌肉的蛋白营养价值造成不良影响。       

福建海域小管枪乌贼肌肉营养成分分析及评价

为了解小管枪乌贼（Loligo oshimai）肌肉营养价值,采用常规生化分析方法对其肌肉的营养成分进行了测定和分析。结果显示,小管枪乌贼肌肉鲜样样品中的水分、粗蛋白质、脂肪、灰分含量分别为（75.50±2.35）%、（19.29±0.98）%、（0.94±0.11）%和（1.80±0.09）%。肌肉中氨基酸含量丰富,共检测出18种氨基酸,含量占干样品的64.32%,4种呈味氨基酸含量为25.16%;必需氨基酸指数（EAAI）为69.77,接近氨基酸标准模式;检测出26种脂肪酸,其中饱和脂肪酸（SFA）8种,单不饱和脂肪酸（MUFA）6种,多不饱和脂肪酸（PUFA）12种,含量分别为42.65%、6.48%和41.55%,不饱和脂肪酸中的二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）占脂肪总量的40.47%;肌肉中矿物元素含量丰富,其中钾（19 420 mg/kg）、锌（43.07 mg/kg）和硒（1.043 mg/kg）含量较高;此外检测的5维生素中V_B6（127.87 mg/kg）和V_B3（91.93 mg/kg）含量丰富。因此,小管枪乌贼肌肉中蛋白质含量丰富、脂肪酸组成比例适宜、矿物元素和维生素含量较高,是一种营养价值全面、味道鲜美、具有较高保健价值的水产品。     

Estimation of body composition from bioelectrical impedance of body segments

This study provides values of anthropometric measurements and specific impedance, for a sample of 104 adults. The hypothesis that the body composition can be estimated more accurately from measurements of lengths and impedance values of the body segments than from the whole body was tested. The impedance of upper and lower extremities (arm and leg) and trunk were used to compute estimates of body composition parameters (FFM, FM, %F, TBW, ECW). The results were compared with those estimated by the impedance of the whole body. These comparisons demonstrated that significative differences resulted from body composition obtained by segmental impedance and by the whole body.     

The neural basis of body form and body action agnosia

Visual analysis of faces and nonfacial body stimuli brings about neural activity in different cortical areas. Moreover, processing body form and body action relies on distinct neural substrates. Although brain lesion studies show specific face processing deficits, neuropsychological evidence for defective recognition of nonfacial body parts is lacking. By combining psychophysics studies with lesion-mapping techniques, we found that lesions of ventromedial, occipitotemporal areas induce face and body recognition deficits while lesions involving extrastriate body area seem causatively associated with impaired recognition of body but not of face and object stimuli. We also found that body form and body action recognition deficits can be double dissociated and are causatively associated with lesions to extrastriate body area and ventral premotor cortex, respectively. Our study reports two category-specific visual deficits, called body form and body action agnosia, and highlights their neural underpinnings.     

Scaling of body frontal area and body width in birds

By analyzing a homogenous dataset we show, in contradiction to a previous study, that the scaling of body frontal area (S(b)) with body mass (m(b)) does not differ between passerine and nonpasserine birds. It is likely that comparison of data collected from live passerines with data collected from frozen nonpasserines had led to the incorrect conclusion that the scaling of S(b) varied between the taxa. We suggest that body dimensions collected from frozen specimens, or specimens stored in alcohol, are not applicable to live birds, and that both the current equations presented in the literature for predicting S(b) from m(b) may lead to inaccurate estimates. Using data from preserved specimens, we found that S(b) scales isometrically with m(b) (S(b) proportional, variant m(b) (0.66)), and therefore we found no evidence for larger birds being more streamlined than smaller birds. S(b) scales with negative allometry against wingspan (b), however, and b scales with positive allometry against m(b), so larger birds have smaller S(b) relative to b. In addition, it appears that dorsoventral flattening of the body is a general characteristic of bird's bodies but that it is more pronounced in larger birds, suggesting perhaps a function in terms of increased lift during forward flight. It appears that bird's bodies obey the surface-to-area geometric scaling law, but bird body shape may vary in relation to aerodynamic function. We suggest that a large-scale study, simultaneously measuring S(b) and m(b) in live passerines and nonpasserines, is required to improve the predictive power of S(b) upon m(b) scaling equations, which play a key role in the estimation of mechanical power consumption in flight in birds. Furthermore, the relations between bird body shape and axial skeleton dimensions, with reference to aerodynamic adaptation, warrant further investigation.     

Effect of body fat and gender on body temperature distribution

It is well known that body composition can influence peripheral heat loss and skin temperature. That the distribution of body fat is affected by gender is well known; however, there is little information on how body composition and gender influences the measure of skin temperature. This study evaluated skin temperature distribution according to body fat percentage (BF%) and gender. A sample of 94 apparently healthy volunteers (47 women and 47 men) was assessed with Dual-Energy X-Ray Absorptiometry (DXA) and infrared thermography (mean, maximum and minimum temperatures – T_Mean, T_Max and T_Min). The sample was divided into groups, according to health risk classification, based on BF%, as proposed by the American College of Sports Medicine: Average (n = 58), Elevated (n = 16) or High (n = 20). Women had lower T_Mean in most regions of interest (ROI). In both genders, group High had lower temperature values than Average and Elevated in the trunk, upper and lower limbs. In men, palms and posterior hands had a tendency (p < 0.05) for increased temperature along with increased BF%. T_Mean, T_Max and T_Min of trunk, upper and lower limbs were negatively correlated with BF% and the fat percentage of each segment (upper limbs, lower limbs and trunk). The highest correlations found in women were between posterior trunk and BF% (rho = −0.564, p < 0.001) and, in men, between anterior trunk and BF% (rho = −0.760, p < 0.001). Overall, this study found that women have lower skin temperature than men, which was related with higher BF%. Facial temperature seems not to be influenced by body fat. With the future collection of data on the relationship between BF% and skin temperature while taking into account factors such as body morphology, gender, and ethnicity, we conclude that measurement of BF may be reliably estimated with the use of thermal imaging technology.     

数字化人体

人体结构的三维成像构造或数字化人体的概念是在医学领域提出来的。利用三维或高维内科成像将人体组织的事件储存为一个三维数据库,再利用计算机技术将人体或人体的组织构建成三维的图像。这样就可以在数字化的人体中进行对真正人体或人体的组织的回顾性观察和分析,而且,这种操作通过现代的计算机网络系统可以远程进行。     

Growth and body composition of mice selected for high body weight

To elucidate the influence of high body weight selection on body compositional relationships, the accumulation of lipid, protein, and ash was investigated in two lines of mice selected for high 42-day body weight (H lines) and an unselected foundation population (FP). The two H lines differed in population size and were designated as the high-large (HL) and high-small (HS) lines. Logistic body growth curves revealed that HL mice exhibited an accelerated growth rate and reached a higher mature body weight than FP or HS mice. Over the range of body weights examined, HL mice had more lipid, less protein, and less ash than FP or HS mice of the same sex and body weight. However, HL lipid accumulation (relative to body weight increase) was not accelerated in comparison to that of FP mice. This study suggests that the existing model of selection-mediated compositional changes requires expansion to account for the ability of high-growth selection to direct an acceleration of body growth without a correlated enhancement of the relative rate of fat accumulation.