茶多酚EGCG抗鼻咽癌的体外实验研究

目的研究茶多酚表没食子儿茶素没食子酸酯（EGCG）对体外培养鼻咽癌细胞的抑制作用。方法选用HNE1细胞系,采用四甲基偶氮唑盐微量酶反应比色法（MTr法）和台盼蓝染色法检测不同浓度EGCG分别在给药不同时间后对HNE1细胞体外增殖的抑制作用。结果MTY法和台盼蓝法都发现EGCG对HNE1细胞体外增殖的抑制作用有浓度一时效关系。这两种方法都适用于检测EGCG对HNE1细胞体外增殖的抑制作用。结论EGCG也许能用于鼻咽癌的预防和治疗。     

Vasa vasorum of the human great saphenous vein

The distribution of the vasa vasorum of the human great saphenous vein (GSV) was studied on veins taken both post-mortem and peroperatively. It was found that the stems of feeding vessels approach the venous wall at intervals of 1.5-2.5 cm; their smaller branches first passed the fascial compartments of the GSV and then entered the adventitia at intervals of 0.5-1.5 cm on both the stem and the largest tributaries of the GSV. In the stem regions vasa vasorum arteries and veins ran together but, between neighboring stems, isolated venae vasorum were regularly found which opened individually into terminal segments of the largest tributaries of the GSV. Neither by dissection nor by injection methods were venae vasorum found to open directly into the lumen of the GSV stem. The total thickness of the media ranged between 500 and 1300 µm, according to the state of constriction of the venous wall before fixation. Two structurally different layers of GSV tunica media were present: an inner loose layer and an outer dense layer, both of similar thickness. The innermost capillaries of the vasa vasorum network were found in all cases on the border between the two layers of media. No lymphatic was found in any of the layers of GSV wall. From the findings the authors recommend extremely careful dissection of the GSV wall during in situ grafting surgery, to ensure the best viability of the venous wall. Résumé. La distribution des vasa vasorum de la veine grande saphène de l'homme a été étudiée sur des veines prélevées chez le cadavre et au cours d'interventions chirurgicales. Nous avons trouvé que les troncs des vaisseaux nourriciers gagnent la paroi veineuse à des intervalles de 1,5 à 2,5 cm. Leurs plus petites branches passent d'abord le fascia fermant le compartiment de la veine grande saphène, puis pénètre l'adventice à des intervalles de 0,5 à 1,5 cm, à la fois sur le tronc et sur les plus grands affluents de la veine grande saphène. Dans les régions des troncs, les artères et les veines cheminaient ensemble mais, entre les troncs voisins, des venae vasorum isolés étaient étagés régulièrement et s'ouvraient individuellement dans les segments terminaux des plus grands affluents de la veine grande saphène. Ni par la dissection, ni par les techniques d'injection nous n'avons trouvé des venae vasorum qui s'ouvraient directement dans la lumière du tronc de la veine grande saphène. L'épaisseur totale de la média variait de 500 à 1300 µm en fonction de l'état de constriction de la paroi veineuse avant la fixation. Il y avait dans la media de la veine grande saphène deux couches structurellement différentes, une couche interne lâche et une couche externe dense, toutes deux d'épaisseur approximativement similaire. Les capillaires les plus profonds du réseau des vasa vasorum étaient trouvés dans tous les cas à la frontière entre les deux couches de la media. Aucun lymphatique n'a été trouvé dans aucune des couches de la paroi de la veine grande saphène. A partir de leurs constatations, les auteurs recommandent la dissection la plus soigneuse de la paroi de la veine grande saphène au cours de la chirurgie de greffe veineuse in situ, pour assurer la meilleure viabilité de la paroi veineuse.     

Diabetes and reactivity of isolated human saphenous vein

Helical strips of saphenous veins from diabetic (n = 8) and non-diabetic (n = 18) humans were studied in vivo for their responsiveness to several vasoactive agents. Following application of passive force (approximately 20.0 mN), venous strips from non-diabetic humans often developed spontaneous phasic contractile activity (12 out of 18 patients; 2-5 contractions/min). These intrinsic changes in force were seen in venous strips from only one diabetic patient. The phasic contractions were not altered by treatment with phentolamine, whereas the calcium channel blocker, D-600, and calcium-free solution (1.0 mM EGTA) inhibited the phasic contractions. Saphenous veins from diabetic patients developed less maximal, active tension in response to norepinephrine than those from non-diabetic patients. Contractile responses to serotonin, angiotensin II, and elevated potassium concentration in saphenous veins from diabetic patients were not different from those in veins from non-diabetic patients. These observations demonstrate attenuated development of active tension in response to alpha-adrenergic receptor activation and reduced spontaneous contractile activity in venous smooth muscle from diabetic patients.     

Vasa vasorum of the human great saphenous vein

The distribution of the vasa vasorum of the human great saphenous vein (GSV) was studied on veins taken both post-mortem and peroperatively. It was found that the stems of feeding vessels approach the venous wall at intervals of 1.5-2.5 cm; their smaller branches first passed the fascial compartments of the GSV and then entered the adventitia at intervals of 0.5-1.5 cm on both the stem and the largest tributaries of the GSV. In the stem regions vasa vasorum arteries and veins ran together but, between neighboring stems, isolated venae vasorum were regularly found which opened individually into terminal segments of the largest tributaries of the GSV. Neither by dissection nor by injection methods were venae vasorum found to open directly into the lumen of the GSV stem. The total thickness of the media ranged between 500 and 1300 micro m, according to the state of constriction of the venous wall before fixation. Two structurally different layers of GSV tunica media were present: an inner loose layer and an outer dense layer, both of similar thickness. The innermost capillaries of the vasa vasorum network were found in all cases on the border between the two layers of media. No lymphatic was found in any of the layers of GSV wall. From the findings the authors recommend extremely careful dissection of the GSV wall during in situ grafting surgery, to ensure the best viability of the venous wall.     

Contractile activity of human greater saphenous vein mediated by P2-receptors

In vitro experiments were carried out to measure the contractile responses to P₂-receptor agonists in the greater saphenous vein isolated from patients with obliterating vascular atherosclerosis and varicose veins of the legs. In patients with varicose veins, the contractile responses of the greater saphenous vein to ATP, ,-methylene-ATP, and UTP were significantly lower than in patients with obliterating atherosclerosis, while the responses to ADP, adenosine, and 2-methylthio-ATP were similar in both groups. These data attest to the presence of P₂-receptor-mediated contraction component in the greater saphenous vein, which are pronouncedly weakened during varicose disease.     

The autonomic innervation of the human greater saphenous vein

The existence of a double catecholaminergic and cholinergic innervation was demonstrated in the human greater saphenous vein. Catecholamine-containing nerve fibres are organized in a network-like plexus localized at the adventitial-medial border. Acetylcholinesterase-containing nerve fibres are arranged in a plexus found at the adventitial-medial border as well. Catecholamine and acetylcholinesterase-containing nerve fibres, while localized in close apposition since they occupy the same portion of the vein, represent two distinct and independent populations of nerve fibres coming likely from the sympathetic and parasympathetic sections of the autonomic nervous system respectively. Our findings demonstrating a close relationship between catecholaminergic and cholinergic nerve fibres within the wall of the human greater saphenous vein offer morphological support to physiological and pharmacological results reported in the literature of a presynaptic control exerted by cholinergic nerves on norepinephrine release at the level of the saphenous vein.     

Special modes of corrosion under physiological and simulated physiological conditions

The aim of this article is to review those aspects of corrosion behaviour that are most relevant to the clinical application of implant alloys. The special modes of corrosion encountered by implant alloys are presented. The resistance of the different materials against the most typical corrosion modes (pitting corrosion, crevice corrosion and fretting corrosion) is compared, together with observations of metal ion release from different biomaterials. A short section is dedicated to possible galvanic effects in cases when different types of materials are combined in a biomedical device. The different topics covered are introduced from the viewpoint of materials science, and then placed into the context of medicine and clinical experience.     

Absence of inflammatory conditions in human varicose saphenous veins

Introduction

Varicose veins affect one-third of the adult population in western countries, but their pathogenesis is incompletely characterized. One of the most controversial issues is the role of inflammation. It is well known that inflammation involves an increased expression/activity of inflammatory mediators.

Objective

The aim of this study was to investigate the presence or absence of mediators of inflammation in varicose as compared to healthy veins.

Methods and results

Using immunohistofluorescence on varicose and healthy veins, we investigated the presence of inflammatory cells. They were not detectable. Venous wall C-reactive protein (CRP), fibrinogen (EIA) and pentraxin-3 (Western blot) content were measured. CRP was significantly lower in varicose veins, but no difference was found for fibrinogen or pentraxin-3 between varicose and healthy veins. No difference was observed for enzymes involved in inflammation and responsible for arachidonic acid metabolism such as the acute phase reactant secreted phospholipase A₂-IIA and cyclooxygenase-2, as determined in varicose and healthy veins by Western blot and real-time qRT-PCR.

Conclusions

Our experiments demonstrate no increase in the presence of mediators of inflammation in varicose as compared to healthy veins, suggesting that inflammation may not be an important contributor to the pathogenesis of varicose veins.     

Intimal proliferation in an organ culture of human saphenous vein.

This study investigated whether intimal proliferation, the characteristic feature of the response of human saphenous vein to arterial implantation, also occurs in organ culture. Vein segments were maintained for 14 days in medium supplemented with 30% fetal bovine serum. Tissue viability (measured by adenosine triphosphate [ATP] concentration) decreased only 20% from 280 +/- 20 to 220 +/- 20 nmol/g wet weight. In veins prepared for culturing, endothelial loss (approximately 20%) was confined to near the cut edges. Cultured veins retained an endothelial layer in the initially undamaged areas, while the initially injured areas became covered by a mixture of endothelial and vascular smooth muscle cells. Autoradiography in conjunction with scanning electron microscopy showed the presence of proliferating cells on the intimal surface. Transverse sections of cultured veins showed the development of a new intima containing vascular smooth muscle cells identified by immunocytochemistry with anti-alpha-actin. There were also endothelial cells identified with Ulex europaeus lectin arranged in capillarylike structures. Pulse or continuous labeling of cultures with [3H]thymidine showed that proliferating cells were confined to the new intima and suggested that the smooth muscle cells in this layer arose from both immigration and proliferation. The results demonstrate that intimal proliferation occurs in organ culture of human saphenous veins.     

Interaction of green tea polyphenol epigallocatechin-3-gallate with sunitinib: potential risk of diminished sunitinib bioavailability

Sunitinib, a novel oral multi-targeted tyrosine kinase inhibitor for patients with metastatic renal cell carcinoma (mRCC) and advanced gastrointestinal stromal tumor, has a good prospect for clinical application and is being investigated for the potential therapy of other tumors. We observed the phenomenon that drinking tea interfered with symptom control in an mRCC patient treated with sunitinib and speculated that green tea or its components might interact with sunitinib. This study was performed to investigate whether epigallocatechin-3-gallate (EGCG), the major constituent of green tea, interacted with sunitinib. The interaction between EGCG and sunitinib was examined in vitro and in vivo. ¹H nuclear magnetic resonance (¹H-NMR) spectroscopy and mass spectrometry (MS) were used to analyze the interaction between these two molecules and whether a new compound was formed. Solutions of sunitinib and EGCG were intragastrically administered to rats to investigate whether the plasma concentrations of sunitinib were affected by EGCG. In this study, we noticed that a precipitate was formed when the solutions of sunitinib and EGCG were mixed under both neutral and acidic conditions. ¹H-NMR spectra indicated an interaction between EGCG and sunitinib, but no new compound was observed by MS. Sticky semisolid contents were found in the stomachs of sunitinib and EGCG co-administrated mice. The $ {\text{AUC}}_{{0 - \infty }} $ and C _max of plasma sunitinib were markedly reduced by co-administration of EGCG to rats. Our study firstly showed that EGCG interacted with sunitinib and reduced the bioavailability of sunitinib. This finding has significant practical implications for tea-drinking habit during sunitinib administration.     

A comparative study on the mechanical properties of the healthy and varicose human saphenous vein under uniaxial loading

Abstract

Saphenous Vein (SV) due to fatness, age, inactiveness, etc. can be afflicted with varicose. The main reason of the varicose vein is believed to be related to the leg muscle pump which is unable to return the blood to the heart in contradiction of the effect of gravity. As a result of the varicose vein, both the structure and mechanical properties of the vein wall would alter. However, so far there is a lack of knowledge on the mechanical properties of the varicose vein. In this study, a comparative study was carried out to measure the elastic and hyperelastic mechanical properties of the healthy and varicose SVs. Healthy and varicose SVs were removed at autopsy and surgery from seven individuals and then axial tensile load was applied to them up to the failure point. In order to investigate the mechanical behaviour of the vein, this study was benefitted from three different stress definitions, such as 2nd Piola-Kichhoff, engineering and true stresses and four different strain definitions, i.e. Almansi-Hamel, Green-St. Venant, engineering and true strains, to determine the linear mechanical properties of the SVs. A Digital Image Correlation (DIC) technique was used to measure the true strain of the vein walls during load bearing. The non-linear mechanical behaviour of the SVs was also computationally evaluated via the Mooney-Rivlin material model. The true/Cauchy stress–strain diagram exhibited the elastic modulus of the varicose SVs as 45.11% lower than that of the healthy ones. Furthermore, by variation of the stress a significant alteration on the maximum stress of the healthy SVs was observed, but then not for the varicose veins. Additionally, the highest stresses of 4.99 and 0.65 MPa were observed for the healthy and varicose SVs, respectively. These results indicate a weakness in the mechanical strength of the SV when it becomes varicose, owing to the degradation of the elastin and collagen content of the SV. The Mooney-Rivlin hyperelastic and the Finite Element (FE) data were finally well compared to the experimental data.     

Effects of a-adrenoceptor subtype-selective antagonists on the human saphenous vein in vivo

The effects of the α-adrenoceptor subtype-selective antagonists prazosin (α¹) and yohimbine (α₂) on the saphenous vein of six healthy male subjects were investigated in vivo. The drugs were infused locally into the congested (40 mmHg), long saphenous vein constricted by simultaneous local infusion of noradrenaline (NA). Prazosin 10^-9 M (concentration in the infusion solution, infusion rate 0.3 ml min^_I) did not reduce the NA-induced venoconstriction, but at a concentration of 10^-8 M there was a significant reduction; in two subjects no response to NA could be elicited in the presence of 10^-8 M prazosin. Prazosin 10^-7 M caused no further reduction of the NA effect compared to that produced by 10^-8 M in three of the subjects, whereas in one, prazosin 10^-9, 10^-8 and 10^-7 M caused a dose-dependent blockade. Yohimbine, 10^-9, 10^-8 and 10^-7 M caused a dose-dependent reduction of the NA-induced venoconstriction in all subjects. The results suggest that the human saphenous vein is endowed with functionally important populations of both α₂- and a₁-adrenoceptors.     

Effects of alpha-adrenoceptor subtype-selective antagonists on the human saphenous vein in vivo

The effects of the alpha-adrenoceptor subtype-selective antagonists prazosin (alpha 1) and yohimbine (alpha 2) on the saphenous vein of six healthy male subjects were investigated in vivo. The drugs were infused locally into the congested (40 mmHg), long saphenous vein constricted by simultaneous local infusion of noradrenaline (NA). Prazosin 10(-9) M (concentration in the infusion solution, infusion rate 0.3 ml min-1) did not reduce the NA-induced venoconstriction, but at a concentration of 10(-8) M there was a significant reduction; in two subjects no response to NA could be elicited in the presence of 10(-8) M prazosin. Prazosin 10(-7) M caused no further reduction of the NA effect compared to that produced by 10(-8) M in three of the subjects, whereas in one, prazosin 10(-9), 10(-8) and 10(-7) M caused a dose-dependent blockade. Yohimbine, 10(-9), 10(-8) and 10(-7) M caused a dose-dependent reduction of the NA-induced venoconstriction in all subjects. The results suggest that the human saphenous vein is endowed with functionally important populations of both alpha 2- and alpha 1-adrenoceptors.     

Leiomyosarcoma of the saphenous vein.

A case of primary leiomyosarcoma of the greater saphenous vein with metastatic spread to the thyroid gland and subcutaneous tissue is described. The literature of saphenous vein leiomyosarcomas is reviewed.     

The caliber of the human long saphenous vein and its congenital variations

The purpose of the present study is to evaluate the caliber of the normal human long saphenous vein (LSV) in order to verify the occurrence of congenital narrowings. The LSV morphology was evaluated by the dissection of 32 cadaveric limbs, and by ultrasonography of 102 healthy living subjects. The LSV caliber was constant in most of the limbs, showing only a mild and progressive increase from the ankle to the groin. Furthermore, great individual variation in LSV caliber was found. A segmental narrowing of the LSV was present in 39.8% of limbs. The narrow segment was visible with the naked eye during dissection or by ultrasonography in 22.4% of cases (LSV hypoplasia). In the remaining 17.4% the caliber was so reduced that it could only be detected microscopically (LSV aplasia). In relation to the narrow segments, the main ascending flow was shunted in a collateral vein running within the superficial hypodermis. The narrow segments of the LSV had a weaker and less muscular wall than did those of normal caliber. Hypoplasia and aplasia of the LSV are probably due to segmental failure in the development of the vessel, and represent a risk factor for varicosis. In fact, the ascending flow is shunted from the LSV in a collateral vein that runs in the yielding superficial fatty layer of the hypodermis. Furthermore, the high incidence of LSV segmental hypoplasia and aplasia has also to be considered whenever this vein is used as an arterial graft, because of the marked anatomical remodelling.     

大隐静脉移植修复腋动脉损伤

目的:探讨腋动脉损伤的治疗方法.方法:采用显微外科技术对10例腋动脉损伤患者行自体大隐静脉移植修复.结果:10例均存活,未出现患肢坏死;1例出现缺血性肌挛缩并发症.结论:大隐静脉移植修复腋动脉损伤是一种有效、安全、并发症少的手术方法.     

Global bioheat model for quick evaluation of the human physiological thermal profiles under differing conditions

The paper presents a physical and mathematical model of the thermoregulatory system of the human body. The model takes into account tissue physiology, structure and general physiological parameters such as blood flow. The global response of the body to underlying physiological variations as well as to any change in ambient conditions can be simulated. The analysis is based on a one-dimensional tissue layer and a two-node core and shell array of the entire body. Application of the model indicates that the body is particularly sensitive to ambient changes in the cold, where a slight drop in gain produces an adverse change in the temperature profile of the physiological system. The gain, G, of the feedback system also suggests that it is an essential parameter in determining the range of the negative feedback as well as the sensitivity of the unacclimizated body to its surroundings. It is also the critical parameter to determine how hard the feedback system works to maintain a homeostatic state. At temperature extremes, G either will cause the system to attain beyond the critical temperatures needed for survival or it will cease to cause the system to respond further to any more changes in the external environment.