兔肋软骨解剖及生物力学实验模型研究

目的:通过对兔肋软骨进行解剖测量以及生物力学测试,探索建立兔肋软骨解剖及生物力学实验模型的方法。方法:对8只新西兰大白兔进行解剖,观察胸廓及肋骨、肋软骨的结构和排列。剥离软骨膜后测量肋软骨的长度及横径;对第4至第7肋软骨进行压缩测试和拉伸测试。结果:兔胸廓是由胸骨、肋骨(含肋软骨)及脊柱构成的上小下大的笼状结构,多数兔拥有12对肋骨,12.5%有13对肋骨。其中第1-7肋通过软骨直接与胸骨相连,称为真肋;第8-10肋软骨不直接与胸骨相连,而是通过韧带连接,称为假肋;第11-13肋游离在腹壁中,是为浮肋。肋软骨的长度从第1至第7肋逐渐增加,从第8至第13肋逐渐减少。真肋的横径明显比假肋及浮肋的大。正常兔肋软骨压缩测试中抗压强度平均12.73±1.06 MPa,极限压缩应变平均63.77%±2.67%,压缩模量平均27.64±1.88 MPa;拉伸测试中抗拉强度平均3.78±0.48 MPa,极限拉伸应变19.79%±2.38%,拉伸模量平均25.94±4.09MPa。结论:新西兰大白兔可提供数量可观且有一定尺寸的肋软骨,其力学性能与青年人类肋软骨接近,可作为研究软骨手术操作的实验动物。     

Linking hyperelastic theoretical models and experimental data of vaginal tissue through histological data

Mechanical characterization of living tissues and computer-based simulations related to medical issues, has become increasingly important to improve diagnostic processes and treatments evaluation. This work proposes a link between the mechanical testing and the material model predictions through histological data of vaginal tissue. Histological data was used to link tensile testing experiments with material-dependent parameters; the approach was adequate to capture the nonlinear response of ovine vaginal tissue over a large strain range.The experimental data obtained on a previous study, has two main components: tensile testing and histological analysis of the ovine vaginal tissue. Uniaxial tensile test data and histological data were collected from three sheep groups: virgins, pregnant and parous. The distal part of vaginal wall was selected since it is prone to tears induced by vaginal delivery.The HGO (Holzapfel-Gasser-Ogden) model parameters were fitted using a stochastic approach, namely the Simple Genetic Algorithm (SGA). The SGA was able to fit the experimental data successfully (R² > 0.986). The dimensionless coefficient ξ, was highly correlated with histological data. The ratio was seen to increase linearly with increasing collagen content.Coefficient ξ brings a new way of interpreting and understanding experimental data; it connects the nonlinear mechanical behaviour (tensile test) with tissue’s morphology (histology). It can be used as an ‘inverse’ (approximate) method to estimate the mechanical properties without direct experimental measurements, through basic histology.In this context, the proposed methodology appears very promising in estimating the response of the tissue via histological information.     

妊娠中晚期阴道微生态失调及乳酸菌胶囊干预对不良妊娠结局的作用

目的 观察妊娠中晚期妇女阴道微生态状况,探讨应用乳杆菌活菌胶囊纠正阴道微生态失调对不良妊娠结局的预防价值。方法 选择孕13~36周单胎妊娠期妇女560例,取其阴道分泌物,经革兰染色后油镜下观察,进行阴道微生态（阴道菌群的密集度、多样性、优势菌、炎症反应等）状况评价,检测阴道分泌物成分、阴道病原菌类型。对阴道微生态失调孕妇,根据是否接受乳杆菌活菌胶囊治疗分为治疗组和对照组,治疗组给予乳杆菌活菌胶囊,对照组不采用药物干预。追踪随访所有孕妇的妊娠情况,比较阴道微生态正常组、微生态失调治疗组及微生态失调对照组的不良妊娠结局。结果 560例研究对象中,阴道微生态正常 335 例（59.82%）,微生态失调225例（40.18%）。225例微生态失调孕妇中,细菌性阴道病（bacterial vaginosis,BV）32例（14.22%）,阴道假丝酵母菌病（vulvovaginal candidiasis,VVC）56例（24.89%）,滴虫性阴道炎（triehomonal vaginitis,TV）11例（4.89%）,BV和VVC混合感染4例（1.78%）,BV和TV混合感染3例（1.33%）,菌群增殖过度75例（33.33%）,菌群抑制44例（19.56%）。微生态失调组pH值>4.5、过氧化氢、白细胞酯酶、唾液酸苷酶、脯氨酸氨基肽酶、乙酰氨基葡萄糖苷酶阳性比例均明显高于微生态正常组（χ2=55.59~340.06,Ps0.05）。结论 妊娠中晚期容易导致阴道微生态失调,造成不良妊娠结局,乳杆菌活菌胶囊纠正阴道微生态失调对于改善不良妊娠结局有较好的预防作用。     

纵向研究妊娠期妇女的阴道微生态状况

目的分析妊娠期妇女阴道微生态状况的纵向变化。方法选择健康无症状单胎妊娠期妇女50例,分别于孕早期（10.2±2.1）周、孕中期（24.6±3.7）周、孕晚期（33.2±3.4）周,取其阴道分泌物,进行pH、H2O2含量检测及细菌培养,并经革兰染色后在油镜下观察,进行阴道微生态（阴道菌群的密集度、多样性、优势菌、炎症反应状况等）状况评价。结果 （1）50例孕妇中,孕早期38例（76%）阴道微生态正常,其中31例（81.58%）整个孕期维持阴道微生态正常,7例（18.42%）孕妇于孕中期或孕晚期转变为阴道微生态失调;12例（24%）孕早期阴道微生态失调,其中6例（50%）于孕中期或孕晚期转变为阴道微生态正常。（2）无症状性细菌性阴道病随着孕周增加部分可自然消退40%（2/5）。（3）H2O2阳性、阴道pH低者易从阴道微生态失调转为阴道微生态正常。结论妊娠期阴道微生态是动态变化的,部分细菌性阴道炎可自然消退,H2O2阳性及低阴道pH为维持正常阴道微生态的重要因素。     

Biomechanical properties of native and tissue engineered heart valve constructs

Due to the increasing number of heart valve diseases, there is an urgent clinical need for off-the-shelf tissue engineered heart valves. While significant progress has been made toward improving the design and performance of both mechanical and tissue engineered heart valves (TEHVs), a human implantable, functional, and viable TEHV has remained elusive. In animal studies so far, the implanted TEHVs have failed to survive more than a few months after transplantation due to insufficient mechanical properties. Therefore, the success of future heart valve tissue engineering approaches depends on the ability of the TEHV to mimic and maintain the functional and mechanical properties of the native heart valves. However, aside from some tensile quasistatic data and flexural or bending properties, detailed mechanical properties such as dynamic fatigue, creep behavior, and viscoelastic properties of heart valves are still poorly understood. The need for better understanding and more detailed characterization of mechanical properties of tissue engineered, as well as native heart valve constructs is thus evident. In the current review we aim to present an overview of the current understanding of the mechanical properties of human and common animal model heart valves. The relevant data on both native and tissue engineered heart valve constructs have been compiled and analyzed to help in defining the target ranges for mechanical properties of TEHV constructs, particularly for the aortic and the pulmonary valves. We conclude with a summary of perspectives on the future work on better understanding of the mechanical properties of TEHV constructs.     

健康妊娠妇女阴道乳酸杆菌及pH变化的研究

目的研究健康妊娠妇女阴道乳酸菌数量及pH的变化与妊娠时间的关系。方法选择20例健康非妊娠妇女,60例健康妊娠妇女(其中早期妊娠、中期妊娠及晚期妊娠各20例)阴道分泌物进行乳酸杆菌数量检测及pH测定,并对乳酸杆菌产生过氧化氢的情况进行检测。结果随着妊娠时间的增加,乳酸杆菌的数量明显增高,伴随阴道分泌物的pH逐渐降低。结论乳酸杆菌与健康妊娠妇女阴道的生物屏障和酸性环境的维持有重要关系。     

妊娠期女性HPV感染及阴道微生态失衡对妊娠结局及新生儿的影响

探讨妊娠期女性人乳头瘤病毒（HPV）感染及阴道微生态失衡对妊娠结局及新生儿结局的影响,为该类患者的治疗提供参考。

选取2020年6月至2023年6月于我院产检的102例HPV阳性妊娠妇女（HPV阳性组）以及同期产检的78例HPV阴性妊娠妇女（HPV阴性组）为研究对象,于怀孕28～34周时,收集阴道分泌物评价阴道微生态状况;另根据微生态评价结果将HPV阳性组对象分为微生态正常组（n=26）和微生态失调组（n=76）;比较HPV阳性组与HPV阴性组对象阴道微生态情况、妊娠结局及新生儿结局,比较微生态正常组与微生态失调组对象妊娠结局及新生儿结局。

HPV阳性组和HPV阴性组对象滴虫性阴道炎（TV）和外阴阴道假丝酵母菌病（VVC）发生率、阴道清洁度比较差异均无统计学意义（χ²=1.520、0.678、0.111,均P＞0.05）,而阴道pH、细菌性阴道病（BV）发生率、阴道菌群密集度、阴道菌群多样性以及微生态失调发生率比较差异均有统计学意义（χ²=10.106、8.247、4.337、5.236、13.865,均P＜0.05）。HPV阳性组对象早产、宫内感染、产褥感染及产后出血发生率显著高于HPV阴性组（χ²=5.710、10.721、6.799、4.294,均P＜0.05）,而两组对象剖宫产率及胎膜早破发生率比较差异无统计学意义（χ²=1.067、0.666,均P＞0.05）。HPV阳性组新生儿感染发生率显著高于HPV阴性组（χ²=9.001,P＜0.05）,两组胎儿窘迫、新生儿窒息和胎儿宫内生长受限（FGR）发生率比较差异均无统计学意义（χ²=2.503、1.547、0.560,均P＞0.05）。微生态失调组对象早产发生率显著高于微生态正常组（χ²=4.130,P＜0.05）,而两组胎膜早破、宫内感染、产褥感染及产后出血发生率比较差异均无统计学意义（χ²=1.401、0.578、0.141、1.368,均P＞0.05）。微生态失调组与微生态正常组胎儿窘迫、新生儿窒息、FGR和新生儿感染发生率比较差异均无统计学意义（χ²=0.261、0.698、1.057、0.242,均P＞0.05）。

妊娠期HPV感染能引发阴道微生态失调,增加不良母婴结局发生风险。

     

Early pregnancy affects the expression of toll-like receptor pathway in ovine thymus

Toll-like receptors (TLRs) participates in regulation of the maternal immune tolerance during pregnancy, and the thymus is critical for the adaptive immune system. This study hypothesized whether early pregnancy affected the expression of toll-like receptor pathway in the thymus of ewes. In this study, expression of TLRs, tumor necrosis factor receptor associated factor 6 (TRAF6), interleukin 1 receptor associated kinase 1 (IRAK1) and myeloid differentiation primary response gene 88 (MyD88) was detected in maternal thymus during early pregnancy in sheep. Ovine thymuses were collected on day 16 of the estrous cycle, and days 13, 16 and 25 of pregnancy, and expression of TLR members was analyzed by real-time quantitative PCR, western blot and immunohistochemistry analysis. The results revealed that there were decreases in the expression of the mRNA and proteins of TLR2, IRAK1, TRAF6 and MyD88, but increase in TLR5 mRNA and protein. Furthermore, expression of TLR3 and TLR4 proteins peaked at days 13 and 16 of gestation, and MyD88 protein was located in the epithelial reticular cells and thymic corpuscles. In summary, TLR signaling is implicated in regulation of maternal thymic immune, which may be via downregulation of TLR2, IRAK1, TRAF6 and MyD88 during early pregnancy in sheep.     

Biomechanical properties of the emergent aquatic macrophyte Sparganium erectum: Implications for fine sediment retention in low energy rivers

This paper is concerned with the biomechanical properties of the emergent aquatic macrophyte, Sparganium erectum. We present observations of adjustments in the physical characteristics and biomechanical properties of S. erectum during the growing season (April-November) from the River Blackwater, UK. When a pulling device is attached to plant stems to measure their resistance to uprooting, individual plants show remarkable strength in their above- and below-ground biomass (median stem strength when stems break away from the underground biomass, 78 N, median rhizome strength, 39 N) and high resistance to uprooting (median uprooting resistance when entire plants uproot, 114 N). This provides the potential for the species to protect and reinforce the generally soft, silty sediments that it often retains and within which its rhizomes and roots develop in lower energy river environments. There is a propensity for plant stems to break before the plant is uprooted at the beginning and end of the growth season, but for the stems to have sufficient strength in mid season for plant uprooting to dominate. This ensures that rhizome and root systems remain relatively undisturbed at times when the silty sediments in which they grow are poorly protected by above-ground biomass. In contrast, rhizome strength remains comparatively invariant through the growing season, supporting the plant's potential to have a protective/reinforcing effect on fine sediments through the winter when above ground biomass is absent.     

In vitro fermentability and physicochemical properties of fibre substrates and their effect on bacteriological and morphological characteristics of the gastrointestinal tract of newly weaned piglets

Abstract

Fermentability of fibre has a great impact on the bacterial flora along the gastrointestinal tract of newly weaned piglets. Therefore, this parameter was determined by incubating in vitro different fibre substrates (chicory roots, sugar beet pulp, wheat bran and corn cobs) with contents of jejunum or caecum sampled from slaughtered pigs. Incubating with small intestinal contents, lactic acid was the only fermentation product. Fermentability was highest for chicory roots, followed by wheat bran and sugar beet pulp, while corn cobs were not fermented. Based on SCFA formed in the incubations with caecal contents, ranking of the fermentability of the fibre substrates was in the same order. The effect of adding different fibre substrates to diets of newly weaned piglets on bacteriological and morphological aspects of the gastrointestinal tract was also investigated. In Experiment 1 three groups of five piglets, weaned at four weeks of age, received a control feed (C), C supplemented with corn cobs (50 g/kg) or with chicory roots (20 g/kg). In Experiment 2, diet C was supplemented with sugar beet pulp (120 g/kg) or with wheat bran (75 g/kg). After three weeks animals were euthanized and digesta were sampled from stomach, proximal and distal jejunum, caecum and colon. Furthermore, mucosal scrapings were prepared and tissue samples were taken from jejunum, caecum and colon. Viscosity was determined for jejunal, caecal and colon contents. Corn cobs in the feed increased the number of total bacteria, lactobacilli and bifidobacteria in the stomach and proximal duodenum, while a decreased count of streptococci in distal jejunum contents was noted. Chicory roots increased the counts of Escherichia coli in the distal jejunum and on the mucosa, while sugar beet pulp decreased the number of lactobacilli on the mucosa only. Wheat bran seemed to increase the count of E. coli in jejunal digesta and on the mucosa, and also the number of lactobacilli in the stomach and jejunum. Bifidobacterial numbers were increased but only in the proximal part of the jejunum. Fibre substrates affected the concentration of lactate and SCFA in different parts of the intestinal tract. Feeding corn cobs increased villus length in the proximal jejunum by 13%. The number of intra-epithelial lymphocytes in the villous epithelium of proximal and distal jejunum was decreased by corn cobs and chicory roots supplementation while beet pulp and wheat bran had the opposite effect. In Experiment 1, apoptotic index of the mucosa of the distal jejunum was very low and decreased when corn cobs were fed. Mitotic index in the crypts was only affected by the wheat bran diet and a small decrease was noted. It was concluded that the fermentability of fibre was not an ideal criterion for predicting its effects on the flora. The effect of fibres on viscosity of digesta was negligible probably explaining the lack of clear and consistent influences on the intestinal mucosa.     

A comparison between porcine,ovine, and bovine intervertebral disc anatomy and single lamella annulus fibrosus tensile properties

This project aimed to compare gross anatomical measures and biomechanical properties of single lamellae from the annulus fibrosus of ovine and porcine lumbar vertebrae, and bovine tail vertebrae. The morphology of the vertebrae of these species differ significantly both from each other and from human, yet how these differences alter biomechanical properties is unknown. Geometric parameters measured in this study included: 1) absolute and relative intervertebral (IVD) and vertebral body height and 2) absolute and relative intervertebral disc (IVD) anterior‐posterior (AP) and medial‐lateral (ML) widths. Single lamella tensile properties included toe‐region stress and stretch ratio, stiffness, and tensile strength. As expected, the bovine tail IVD revealed a more circular shape compared with both the ovine and porcine lumbar IVD. The bovine tail also had the largest IVD to vertebral body height ratio (due to having the highest absolute IVD height). Bovine tail lamellae were also found to be strongest and stiffest (in tension) while ovine lumbar lamellae were weakest and most compliant. Histological analysis revealed the greatest proportion of collagen in the bovine corroborating findings of increased strength and stiffness. The observed differences in anatomical shape, connective tissue composition, and tensile properties need to be considered when choosing an appropriate model for IVD research. J. Morphol. 277:244–251, 2016. © 2015 Wiley Periodicals, Inc.     

Effects of a Peracetic Acid Disinfection Protocol on the Biocompatibility and Biomechanical Properties of Human Patellar Tendon Allografts

Patellar tendon allografts, retrieved from cadaveric human donors, are widely used for replacement of damaged cruciate ligaments. In common with other tissue allografts originating from cadaveric donors, there are concerns regarding the potential for disease transmission from the donor to the recipient. Additionally, retrieval and subsequent processing protocols expose the graft to the risk of environmental contamination. For these reasons, disinfection or sterilisation protocols are necessary for these grafts before they are used clinically. A high-level disinfection protocol, utilising peracetic acid (PAA), has been developed and investigated for its effects on the biocompatibility and biomechanics of the patellar tendon allografts. PAA disinfection did not render the grafts either cytotoxic or liable to provoke an inflammatory response as assessed in vitro . However, the protocol was shown to increase the size of gaps between the tendon fibres in the matrix and render the grafts more susceptible to digestion with collagenase. Biomechanical studies of the tendons showed that PAA treatment had no effect on the ultimate tensile stress or Young's modulus of the tendons, and that ultimate strain was significantly higher in PAA treated tendons.     

The effects of prolonged deep freezing on the biomechanical properties of osteochondral allografts

Musculo-skeletal allografts sterilized and deep frozen are among the most common human tissue to be preserved and utilized in modern medicine. The effects of a long deep freezing period on cortical bone has already been evaluated and found to be insignificant. However, there are no reports about the influences of a protracted deep freezing period on osteochondral allografts. One hundred osteochondral cylinders were taken from a fresh specimen and humeral heads of 1 year, 2 years, 3 years and 4 year old bones. Twenty chips from each period, with a minimum of 3 chips per humeral head. Each was mechanically tested by 3 point compression. The fresh osteochondral allografts were significantly mechanically better than the deep frozen osteochondral allografts. There was no statistical significant time dependent difference between the deep frozen groups in relation to the freezing period. Therefore, we conclude that, from the mechanical point of view deep freezing of osteochondral allografts over a period of 4 years, is safe without further deterioration of the biomechanical properties of the osteochondral allografts.     

Effect of freeze-drying and gamma irradiation on biomechanical properties of bovine pericardium

Freeze-drying and gamma irradiation are the techniques widely use in tissue banking for preservation and sterilization of tissue grafts respectively. However, the effect of these techniques on biomechanical properties of bovine pericardium is poorly known. A total of 300 strips of bovine pericardium each measured 4 cm × 1 cm were used in this study to evaluate the effect of freeze-drying on biomechanical properties of fresh bovine pericardium and the effect of gamma irradiation on biomechanical properties of freeze-dried bovine pericardium. The strips were divided into three equal groups, which consist of 100 strips each group. The three groups were fresh bovine pericardium, freeze-dried bovine pericardium and irradiated freeze-dried bovine pericardium. The biomechanical properties of the pericardial strips were measured by a computer controlled instron tensiometer while the strips thickness was measured by Mitutoyo thickness gauge. The results of the study revealed that freeze-drying has no significant (p > 0.05) effect on the tensile strength, Youngs modulus (stiffness) and elongation rate of fresh bovine pericardium. Irradiation with 25 kGy gamma rays caused significant decreased in the tensile strength, Youngs modulus and elongation rate of the freeze-dried pericardium. However, gamma irradiation has no significant effect on the thickness of freeze-dried bovine pericardium, while freeze-drying caused significant decreased in the thickness of the fresh bovine pericardium. The outcome of this study demonstrated that freeze-drying has no significant effect on the biomechanical properties of fresh bovine pericardium, and gamma irradiation caused significant effect on the biomechanical properties of freeze-dried bovine pericardium.     

Postinsemination treatment of primiparous and multiparous cows with cloprostenol failed to affect ovulation and pregnancy rate in dairy cattle

Previous studies have demonstrated the facilitating effect of a single cloprostenol treatment postinsemination on ovulation and pregnancy rate in dairy cattle and Italian buffalos. This study was conducted to test the effects of 500 μg cloprostenol given intramuscularly immediately postinsemination to 55 primiparous and 60 multiparous Holstein cows (Bos taurus; TR) of a typical dairy operation in East Germany and to compare them with 57 primiparous and 48 multiparous saline-treated cows (CON). Animals of the TR and CON groups did not differ or only differed marginally for age at treatment, interval calving–treatment, lactation number, milk production on the day of treatment, body condition score, and their peri- and postparturient case histories. All animals were clinically and reproductively healthy on the day of treatment. They were inseminated once 12 h after the onset of estrus, scanned 24 h after insemination to confirm ovulation, and tested for pregnancy by transrectal palpation between Days 42 and 48 postinsemination. Treatment did not affect the number of cows ovulating. The overall combined pregnancy rate (PR) was 47.3%. Pregnancy rate did not differ statistically between TR and CON (46.1% vs. 48.6%; P > 0.05). In conclusion, this study failed to demonstrate beneficial effects of a postinsemination treatment of primiparous and multiparous cows with cloprostenol on ovulation and PR in a typical dairy cattle operation in East Germany.     

The effect of maternal omega-3 long-chain polyunsaturated fatty acid (n-3 LCPUFA) supplementation during pregnancy and/or lactation on body fat mass in the offspring: a systematic review of animal studies

Dietary n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) reduce adipogenesis and lipogenesis in adult rodents, but it is not clear whether an increased n-3 LCPUFA supply during the perinatal period influences body fat mass in the offspring. This systematic review aimed to evaluate the existing evidence from animal studies, which have addressed this question. Medline was searched for relevant articles. Studies were included if they involved maternal n-3 PUFA or LCPUFA supplementation and measured fat mass in the offspring. The design and quality of each study was assessed. Only four animal studies met our inclusion criteria. Three studies reported a lower fat mass in offspring of n-3 LCPUFA supplemented dams, however only one of these studies confined the intervention to the perinatal period. The dose of n-3 PUFA, the nature of the control treatment, the approaches used and outcomes assessed differed between studies. This review highlights the paucity of robust animal data as to the effect of increased n-3 LCPUFA exposure during the perinatal period alone, on body fat mass in the offspring and calls for further studies.     

乳酸菌阴道胶囊联合甲硝唑栓对妊娠晚期BV患者阴道乳酸菌及妊娠结局的影响

目的 探讨乳酸菌阴道胶囊联合甲硝唑栓对妊娠晚期细菌性阴道病（BV）患者阴道乳酸菌数量及妊娠结局的影响。方法 选取产科门诊治疗的妊娠晚期BV妇女110例,随机分为观察组和对照组各55例。观察组予以乳酸菌阴道胶囊（1粒/晨,1次/d）联合甲硝唑栓（1粒/晚,1次/d）阴道给药,对照组予以单纯甲硝唑栓阴道给药治疗,用法与用量同观察组,两组疗程均为10 d。治疗结束后1周复诊观察阴道乳酸菌数量,并比较其临床疗效、妊娠结局及阴道假丝酵母菌病（VVC）的发生率。结果 1周后复诊,观察组患者阴道乳酸菌数量多于对照组（χ2=24.44,P0.05）。观察组和对照组分别诱发VVC 2例（3.64%）和8例（14.55 %）,观察组VVC发生率低于对照组（χ2=3.96,P<0.05）。结论 妊娠晚期BV患者予以乳酸菌阴道胶囊和甲硝唑栓联合治疗的疗效确切,能增加阴道乳酸菌数量,纠正阴道菌群紊乱,减少VVC的发生率,从而减少早产发生率,改善妊娠结局。     

Evaluation of dynamic response and biomechanical properties of isolated blood vessels

In this study we present the experimental and mathematical model for a precise assessment of isolated blood vessels dynamic response under a sudden change of blood pressure. Only the end points within the time interval of the considered dynamic response of the blood vessel, or so-called “alternate steady states” of the processes, were usually considered in various studies. These studies do not provide an insight how the process variables change between these alternate steady states. Isolated blood vessels (rat abdominal aorta) were used to determine how the process dynamics can be described in detailed quantitative terms by mathematical parameters. The experimental model and mathematical procedures presented in this study describe precisely (at a high sensitivity level) the time history of the pressure and the diameter change in between alternate steady states, when an abrupt change of blood pressure occurs at the vessel outlet. Also, the experimental model and mathematical procedures were used to determine changes in the stress–strain law, caused by the action of L-arginine. The presented experimental design and mathematical model can be used for assessment of isolated blood vessel dynamic responses under different stimuli, such as drug effects, electrostimulation etc.