软组织生物力学性状及其形态结构与年龄和性别相关性的研究

发布时间：2018-03-06 19:35

本文选题：年龄推断　切入点：软组织　出处：《汕头大学》2008年硕士论文　论文类型：学位论文

【摘要】： 背景与目的目前,推断年龄主要是依据人体骨骼、细胞、生物大分子,以及组织中各类物质的物理和化学特性等随年龄增长的时序性变化。根据骨骼的多项指标联合观察,能较准确地推断出年龄,是国内外推断年龄的主要手段,为破案侦察和法庭诉讼提供了准确可靠的证据。但对于软组织检材,如皮肤、血痕、毛发等,尚无公认的客观准确的推断年龄方法。近年来,随着分子生物学技术的发展和普及,有报道检测软组织检材的端粒酶等,为推断年龄提供了一种新思路。但受诸多因素的影响,其推断年龄的误差较大,目前还处于研究阶段。本实验基于生物体各组织形态结构随年龄变化的自然规律,应用生物力学的理论和技术,探讨不同年龄、性别组大鼠软组织的生物力学性状与年龄的相关性,旨在为用软组织推断年龄提供一种新的数值量化的技术思路。材料与方法 SD大鼠96只,雌雄各8组,共16组,分别为新生儿组(≤1w)、婴幼儿组(1～4W)、青少年组(1～2个月)、青年组(2～3个月)、中年早期组(3～7个月)、中年中期组(7～11个月)、中年晚期组(11～15个月)、老龄组(≥18月龄),每组6只。于每个分组点颈椎脱臼处死大鼠,立即纵向切取腹壁正中皮肤、腹白线右侧肌肉,小肠上段、结肠下端和胸主动脉壁全段各约5cm,小心剥离各组织周围的结缔组织,备制约1:4的长方形软组织生物力学试件。同时,于相应部位提取组织切片检材及提取脑、心、肝、肾等全身脏器,放入10%的中性甲醛溶液内固定约48小时。步骤:将软组织试样固定于万能材料拉力机特制夹具上,室温下进行4～5次预调,得到较理想的状态后,进行轴向一维拉伸,直至软组织被拉断。每次测试过程不超过3分钟,期间用生理盐水喷洒软组织以保持试件原有水分。电脑软件自动采集检测过程中的试样数据,主要测算指标有:最大应力、断裂时应变、断裂力、最大力变形、弹性模量等。应用SPSS13.0和Excel统计软件进行数据的分析处理。组织切片检材常规脱水、石蜡包埋、切片、HE、VG染色,光镜下观察各组软组织与脑、心、肺、肝、脾、肾等内脏组织的形态学特征。同时,采用显微图象处理技术进行胶原纤维、弹性纤维、肌纤维、肠绒毛高度等的观察测量。结果 1软组织生物力学性状皮肤和肌肉组织的应力随年龄增长而呈先增后减的开口向下“抛物线”型变化,雌鼠的最大应力值在36W龄左右,皮肤、肌肉最大应力值分别约为6.00±1.02 Mpa,1.19±0.17Mpa,雄鼠应力则于20W龄左右达到最大值,皮肤、肌肉最大应力值分别约为6.93±1.13 Mpa,1.36±0.20Mpa,之后随年龄的增长逐渐呈逐渐下降趋势。52W龄以后,雌雄组的应力差别不明显。肠组织的应力性别差异不太明显,10W龄左右达到最大值,之后逐渐下降,而52W龄左右应力又略有增加。血管应力未观察到与年龄和性别相关的明显变化。雌雄鼠皮肤、肌肉、小肠的应变10W左右最大,10～36W处于相对稳定期,52W后开始逐渐呈下降趋势,相同年龄组雌雄大鼠应变不存在显著差别。 2 HE与VG染色的组织形态学观察各年龄段大鼠腹部皮肤全层胶原纤维为主,弹性纤维较少。3W龄的皮肤胶原纤维与弹性纤维最细、最少,胶原纤维束的直径约13.54um。随年龄的增长,弹性纤维与胶原纤维逐渐增粗、排列致密。雌鼠36W左右纤维束最粗大,直径约31.06 um,雄鼠20W左右胶原纤维束最粗大,直径约35.12 um。之后,随年龄的增加,皮肤胶原纤维变细、排布较稀疏紊乱。弹性纤维也随年龄增长变细、变短,72W龄,胶原纤维束的直径约20.67um。大鼠腹壁肌肉横断面直径随年龄增长而增加,1W时肌纤维最细,与成年鼠差异最大。雌鼠约36W、而雄鼠约20W时肌纤维最粗壮、横断面最大,36W龄雌鼠与20W龄雄鼠肌纤维横断分别为11.57um、15.69um,以后随年龄增长呈递减趋势,各年龄段比较P＜0.05。大鼠从6W龄开始小肠绒毛高度、肌层厚度逐渐增加,肌纤维排列逐渐致密。10W龄左右绒毛高度达高峰、肌层最厚、肌纤维排列最致密,以后开始下降,52W龄又略有增加,至72W后小肠绒毛稀疏、短粗,腺体数量减少,肠壁肌层菲薄。雌雄鼠结肠下段除了肠绒毛外,其余变化与小肠基本上一致。胸主动脉20W龄左右弹性膜折叠最丰富。52W后弹性膜折叠的数量与幅度逐渐减小。随着年龄的增加,血管内膜与管壁厚度增加,管腔扩张,管壁厚度与管腔直径比值随年龄的增加而增加。大鼠内脏组织也存在增龄过程中的变化,如老年大鼠脑回变窄、脑沟加宽,神经元数量减少,神经胶质细胞数量和体积增加。老年大鼠心内膜增厚、胶原纤维增多。老年大鼠肝细胞核体积增大,形态大小不一,肝细胞排列疏松,肝小叶中央静脉周围肝细胞排列较紊乱,细胞脂肪空泡增加。结论 1、不同年龄和性别大鼠的皮肤、肌肉应力随年龄增长呈“抛物线”型变化规律,两者呈二元回归关系,雄鼠比雌鼠早一个年龄段达到最大应力值;肠应力呈“M”型变化规律。 2、皮肤胶原和弹力纤维形态结构随年龄的变化、肌纤维直径随年龄的变化,与组织生物力学变化之间存在物质-功能的相关性,鉴于软组织的生物力学特性呈随年龄增长的“抛物线”型变化规律及二元回归关系,应配合组织形态学变化推断年龄。
[Abstract]:Background and purpose
At present, age estimation is mainly based on human bone cells, biological macromolecules, sequential changes and all kinds of material in the physical and chemical characteristic with age. According to the observation of several indexes of skeleton, can accurately infer the age, is the main means to estimate the age at home and abroad, to provide accurate and reliable the evidence for the case of reconnaissance and court proceedings. But for the soft tissue samples, such as skin, blood, hair, objective and accurate method to estimate the age is not recognized. In recent years, with the development of molecular biology and the popularization, has reported the detection of soft tissue samples of telomerase, provides a new way of thinking to estimate the age. But under the influence of many factors, the age estimation error is large, is still in the research stage. The experimental nature of the organizations of the organism structure changes with age based on the application of biological The theory and technology of mechanics are used to explore the correlation between biomechanical properties of soft tissue and age in different age and gender groups, so as to provide a new quantitative method for inferring age from soft tissue.
Materials and methods
96 SD rats, male and female each 8 group, 16 group, respectively (1W), group of newborn infant group (1 ~ 4W), youth group (1~2 months) and young group (2~3 months), early middle age group (3~7 months), middle age group (7~11 month Interim), the late middle age group (11~15 months), aged group (aged 18 month old), 6 rats in each group.
In each group of rats were killed by cervical dislocation point, immediately cut the longitudinal midline abdominal skin on the right side of the linea alba muscle, small intestine, colon and lower thoracic aortic wall intact by about 5cm, be careful around the tissue dissection of connective tissue, by restricting rectangular soft tissue mechanics 1:4 specimens. At the same time, the corresponding parts extraction of tissue samples and extraction of brain, heart, liver, kidney and other organs, neutral fixation into 10% Formaldehyde Solution for about 48 hours.
Steps: soft tissue specimens were fixed in a universal material testing machine special fixture, 4~5 preset at room temperature, get the ideal state, the axial tensile, until soft tissue off. Each test process should not exceed 3 minutes, during spraying with saline soft tissue specimens in order to maintain the original water. The sample data in the detection process of automatic acquisition of computer software, the main indexes are: maximum stress, fracture strain, fracture strength, maximum deformation, elastic modulus and so on. The application of SPSS13.0 and Excel statistical software for analysis of the data processing.
Tissue samples of conventional dehydration, paraffin embedding, slicing, HE, VG staining, observe the soft tissue under light microscope and the brain, heart, lung, liver, spleen, kidney and other viscera tissue morphological characteristics. At the same time, by using collagen fiber, microscopic image processing technology of elastic fibers, muscle fiber, observation and measurement villus height and so on.
Result
1 biomechanical properties of soft tissue
The skin and muscle tissue stress is opening down "parabola" firstly increased and then decreased with the increase of age, the maximum stress value at about 36W in the skin, muscle of female rats, the maximum stress value of approximately 6 + 1.02 Mpa, 1.19 + 0.17Mpa, male rats stress in 20W age as to the maximum value of the skin, muscle, the maximum stress value of about 6.93 + 1.13 Mpa, 1.36 + 0.20Mpa, with age gradually decreased after.52W age group, male and female stress difference is not obvious. Intestinal tissue stress gender difference was not significant, reached the maximum at about 10W the value, then gradually decreased, and at about 52W stress and increased slightly. Vessel stress is not observed with age and sex related changes in male and female rats. The skin, muscle strain, intestinal 10W about 10 ~ 36W maximum, in a relatively stable period, 52W began to gradually decreased, the same age There was no significant difference in strain between the male and female rats.
Histomorphological observation of 2 HE and VG staining
Abdominal skin of rats of all ages full-thickness skin collagen fibers. The collagen fiber and elastic fiber elastic fiber less.3W age of the most fine, at least, collagen fiber bundle diameter of 13.54um. with age, elastic fibers and collagen fibers became thicker, dense. Female rats around 36W fiber bundle the thick diameter about 31.06 um male rats, collagen fibers around 20W thick, after about 35.12 um. in diameter. With the increase of age, the skin collagen fibers became thinner and more sparse arrangement disorder. Elastic fibers with age became thinner and shorter, 72W age, collagen fiber bundle diameter of about 20.67um.
Rat abdominal wall muscle cross-sectional diameter increased with age, 1W muscle fiber fine, the biggest difference with adult rats. Female rats and male rats is about 36W, about 20W of the muscle fiber thick, maximum, 36W old female rats and male rats aged 20W and muscle fiber cross-section were 11.57um, 15.69um, to after the trend of decrease with the increase of age, the age of P is less than 0.05.
The rats began to villus height from 6W age, muscle layer thickness increases gradually, muscle fibers arranged in dense villus height at about.10W reached the peak, the most thick muscle layer, muscle fibers arranged in the most dense, then began to decline, 52W age and slightly increased to 72W after intestinal villi sparse, short, reduce the number of intestinal glands. Thin wall muscle layer. Male and female rats colon segment except the intestinal villi, the change and small intestine is basically the same.
The size and size of elastic membrane were reduced after 20W age. The number and extent of elastic membrane folding decreased gradually. With the increase of age, the thickness of vascular intima and wall increased, lumen dilated, and the ratio of.52W to wall diameter increased with age.
There are also changes in visceral tissues of rats during the aging process, such as the brain of aged rats narrowed sulci widened, reduce the number of neurons, glial cell number and volume increased. Heart intimal thickening in aged rats, increased collagen fibers in aged rat liver nuclei. The increase in size, shape size, arrangement of hepatic cells osteoporosis, lobular liver cells around the central vein disordered cells, fat vacuoles increased.
conclusion
1, the skin and muscle stress of different ages and sexes showed a parabolic type change rule with age. Both of them showed a two element regression relationship. Male rats reached the maximum stress value in one age group, and the intestinal stress showed a "M" rule.
2, the skin collagen and elastic fiber morphology changes with age, muscle fiber diameter changes with age, correlation function between material and tissue biomechanical changes, in view of the biomechanical properties of soft tissue was increased with age "parabola" variation and two regression relationship, with morphological changes of age estimation.

【学位授予单位】：汕头大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：D919

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