Influence of age on 5'-nucleotidase in plasma membranes isolated from rat liver

Studies were carried out to determine the kinetic properties of 5'-nucleotidase from liver plasma membranes in rats of different ages; four groups were examined, namely rats 25 +/- 2, 60 +/- 5, 230 +/- 15 and 525 +/- 20 days old. The 5'-nucleotidase showed minimum Vmax values in young rats; differences in this kinetic parameter were not detected among the other groups. However, the Km values increased during growth and development, declined in young animals and increased again in the middle-aged. Arrhenius plots of the 5'-nucleotidase activity showed a single break at aroung 22 degrees C in developing the middle-aged animals; the break temperature decreased to 17 degrees C in the rats 230 +/- 15 days old. The pH-Vmax and pH-Km curves showed a maximum at pH 7.6 at all ages. Lipid analysis of membrane preparations was carried out. Phospholipid composition did not change markedly with age. The cholesterol level decreased between 25 +/- 2 and 60 +/- 5 days. The degree of saturation of fatty acids seemed to increase in the same period, but reached the lowest value in the young rats. The results indicate that either sphingomyelin or other phospholipids do not affect the isothermal kinetics of 5'-nucleotidase during development and aging. Furthermore, phospholipid polar groups as well as the cholesterol and fatty acids of the bulk lipid phase modulate the membrane fluidity in the same way at different ages. Finally, the modifications of the Km with age cannot be correlated with changes in the surface charge.     

Age-dependent differences in energetic status, electrical and mechanical performance of rat myocardium

Transmembrane action potential (AP), isotonic contraction and biochemical measurements were performed in 12-day, 1-, 3-, 14- and 24-month-old rat hearts. The major findings of this study are: (1) the AP and contraction duration decrease between 12 days and 1 month of age (growth period) and increase between 1 month and 24 months of age; (2) as compared with 1 month and 14 months, respectively, isotonic contraction peak shortening is lower at 12 days and 24 months of age; (3) the phosphorylation potential is higher during the postnatal period and decreases in an age-correlated manner; (4) the inorganic phosphate and glycogen contents are higher in the senescent heart. We conclude that, during the postnatal period the particular AP and the lower mechanical performances could be the result of immature sarcolemma and sarcoplasmic reticulum properties rather than modifications in the oxidative phosphorylation mechanism and by contrast, in senescent heart, that AP and contraction modifications could result from metabolic modifications.     

5'-Nucleotidase activity increases in aging rat brain.

The enzyme 5'-nucleotidase is present in glial and neuronal membranes, and catalyzes the formation of adenosine, which in turn can act as a neuromodulator or neurotransmitter. The present study found marked increases in histochemically demonstrated 5'-nucleotidase activity in most regions of rat brain from young adulthood (3-4 months) to middle age (12-18 months), with smaller or no changes between middle and old age (24-32 months). The aging adult cerebellum showed alterations in the histochemical pattern, with declines in the molecular layer and increases in the Purkinje layer. Both myelin and synaptic plasma membrane fractions from forebrain showed increases in enzyme activity. Assays of various other body tissues suggested that the increases are fairly specific to brain, and thus apparently do not represent a ubiquitous cellular mechanism of aging. Changes in brain 5'-nucleotidase activity during aging probably reflect the increasing number and size of glial cells, and perhaps also affect synaptic transmission through regulation of adenosine.     

Effects of growth and exercise on composition, structural maturation and appearance of osteoarthritis in articular cartilage of hamsters

Articular cartilage composition and structure are maintained and remodeled by chondrocytes under the influence of loading. Exercise‐induced changes in the composition, structure, mechanical properties and tissue integrity of growing and aging hamster articular cartilage were investigated. Articular cartilage samples (n = 191) were harvested from the proximal tibiae of hamsters aged 1, 3, 6, 12 and 15 months. The hamsters were divided into runners and controls. The runners had free access to a running wheel between 1 and 3 months (runner groups 3‐, 12‐ and 15‐month‐old hamsters) or 1 and 6 months (runner group 6‐month‐old hamsters) of age. Control animals were subjected to a sedentary lifestyle. Mechanical indentation tests and depth‐wise compositional and structural analyses were performed for the cartilage samples. Furthermore, the integrity of articular cartilage was assessed using histological osteoarthritis grading. Exercise affected the collagen network organization after a 5‐month exercise period, especially in the middle and deep zones. However, no effect on the mechanical properties was detected after exercise. Before the age of 12 months, the runners showed less osteoarthritis than the controls, whereas at 15 months of age the situation was reversed. It is concluded that, in hamsters, physical exercise at a young age enhances cartilage maturation and alters the depth‐wise cartilage structure and composition. This may be considered beneficial. However, exercise at a young age demonstrated adverse effects on cartilage at a later age with a significant increase in the incidence of osteoarthritis.     

Intrauterine administration of levonorgestrel in two low doses in HRT. A randomized clinical trial during one year: effects on lipid and lipoprotein metabolism

Objective: To investigate the effects on lipid and lipoprotein metabolism of two doses (5- or 10 μg/24 h) of levonorgestrel released from an intrauterine device (IUD) in combination with orally administered estradiol (2 mg estradiol valerate) in perimenopausal women. Design: A 1-year prospective randomized single blind clinical trial. setting: Department of Obstetrics and Gynaecology, Östra Hospital, Göteborg, Sweden. Subjects: Fifty-one perimenopausal women with climacteric symptoms. Outcome measures: Cholesterol in serum and in lipoprotein fractions; high-density lipoprotein 9HDL), low-density lipoprotein (LDL). Triglycerides in serum and in very low-density lipoprotein. Results: In both treatment groups significant elevations in HDL-cholesterol of similar magnitude were observed after 1 month and these changes were maintained during the 12 month observation period. In both treatment groups an initial significant decrease of LDL-cholesterol was observed and the decrement was maintained after 12 months. Serum levels of cholesterol decreased significantly in both groups after 1 month and were maintained after 12 months in the levonorgestrel-IUD (LNG-IUD) 5 μg group. However, the initial reduction of serum cholesterol in the LNG-IUD 10 μg group did not differ from baseline after 12 months. Serum triglyceride levels fluctuated during the observation period. No significant changes occurred. Conclusion: continuous combined HRT with intrauterine administration of levonorgestrel, 5- or 10 μg/24 h, in perimenopausal women was observed to increase HDL-cholesterol and to decrease LDL-cholesterol compared with pretreatment values. the low doses of levonorgestrel did not reverse the beneficial effects on lipid metabolism usually seen after estradiol administration.     

Brain lipid hydroperoxide level increases in senescence-accelerated mice at an early age

We previously reported that the levels of lipid hydroperoxides, one of oxidative stress markers, in the brain and peripheral organs such as liver, heart, and lung are significantly higher in senescence accelerated-prone 8 mice (SAMP8) than in their controls, senescence accelerated-resistant mice (SAMR1), at 3, 6, and/or 9 months of age. To ascertain the exact age at which the lipid hydroperoxide levels increase in SAMP8, we measured them in the brain and liver of SAMP8 and SAMR1 at both 1 and 2 months of age. At 1 month of age, there was no significant inter-strain difference in the levels in brain or liver. However, in SAMP8 both levels were significantly greater at 2 months of age than at 1 month of age, but no such difference was detected for SAMR1. The present results suggest that SAMP8 are exposed to elevated levels of oxidative stress from an early age (2 months old), and that this may be a cause of the senescence-related impairments and degeneration in the brain and peripheral tissues (such as liver, heart, and lung) seen in this strain.     

Immunogenicity and safety in adults of hepatitis A virus vaccine administered as a single dose with a booster 6 months later

An inactivated vaccine against hepatitis A was administered as a single 1,440 enzyme-linked immunosorbent assay (ELISA) units dose at month 0 with a booster at month 6 to 200 subjects divided into two age groups: group 1, 20–39 years (n = 134) and group II, 40–62 years (n = 66). At day 15, the seropositivity rates were 90% and 77% in groups I and II, respectively. At month 1 the seropositivity rate was 97% in both groups. At month 6 the seropositivity rates were 94% and 88% in groups I and II, respectively. One month after the booster, at month 7, 100% in both groups had become seropositive. The vaccine was well tolerated and did not cause any severe reactions. The results indicate that a single high vaccine dose offers protection against hepatitis A virus (HAV) for at least 6 months in the majority of cases where rapid vaccination is required even in travellers of older age. A booster dose will ensure long-term protection. © 1994 Wiley-Liss, Inc.     

Age-dependent alterations in lipids and function of rat heart sarcolemma

The objective of the present study was to examine the effect of age on heart sarcolemma structure and function. Sarcolemmal fractions were prepared from hearts of young (1–1.5 months) and adult (10–12 months) rats and assayed for marker enzyme activities. The membrane fractions were found to be devoid of other cellular organelles upon examination by electron microscopy. They were enriched with 5′-nucleotidase and devoid of succinate dehydrogenase activity. The only age-related lipid compositional changes noted in these membranes were changes in the fatty acid composition of membrane phospholipids with increasing age. Most changes were detected in phosphatidylcholine and phosphatidylethanolamine with very little alteration of sphingomyelin and phosphatidylserine plus phosphatidylinositol fatty acids. Polyunsaturated fatty acids, especially 18:2 and 20:4, were decreased with saturated fatty acids increased in membrane phosphatidylcholine and phosphatidylethanolamine fractions as the animal develops. There was a decrease in the specific activities of(Na⁺ + K⁺)-ATPase and 5′-nucleotidase of these membranes with age. On the other hand, membrane (K⁺)-p-nitrophenylphosphatase was not affected by age.     

重庆地区4—12月龄体重增加不足婴儿能量摄入状况的研究

目的以体重增加为标准，探讨体重增加不足与能量摄入的相关性。方法2004年11月至2005年12月在重庆医科大学儿童医院儿童保健门诊进行健康体格检查的婴儿，年龄4～12个月，由2名儿童保健专业人员负责体格测量。体格评价以美国疾病预防与控制中心的标准为参数。以两次体检体重／年龄Z值之差（△WAZ）将研究对象分为体重增加不足组和体重增加正常组，同时两组按月龄分为4～5月龄、～8月龄和～12月龄3个亚组。以食物称重与食物记录法计算每日食物摄入情况。结果研究期间共纳入202名婴儿，体重增加不足组70名（-2〈△WAZ〈～0．67），体重增加正常组132名（-0．67≤△WAZ≤0．67）。①体重增加不足组体格发育水平在正常生长范围内，但略低于体重增加正常组。②体重增加不足组除乳类摄入量较体重增加正常组低外（P〈0．05），其他食物摄入量接近于体重增加正常组（P〉0．05），蛋白质摄入量达WHO和中国营养协会推荐摄入量；体重增加不足组中4～5月龄、～8月龄和～12月龄亚组能量摄入分别为322kJ·kg^-1·d^-1（77kcal·kg^-1·d^-1）、322kJ·kv（77kcal·kg^-1·d^-1）和310kJ·kg^-1·d^-1（74kcal·kg^-1·d^-1），显著低于体重增加正常各月龄亚组的351kJ·kg^-1·d^-1（84kcal·kg^-1·d^-1），343kJ·kg^-1·d^-1（82kcal·kg^-1·d^-1）和360kJ·kg^-1·d^-1（86kcal·kg^-1·d^-1）（P〈0．05），其中～12月龄亚组摄入食物总能量中谷类食物产能较低（P〈0．05）；体重增加不足与体重增加正常各月龄亚组摄入食物的能量密度相近（P〉0．05）。⑧Logistic分析显示婴儿体重增加不足的风险因素（OR=3．947）是能量摄入不足，母亲文化程度高是婴儿体重增加正常的保护因素（OR=0．437）。结论①排除相关干扰因素，能量摄入不足造成婴儿体重增加不足的主要原因是乳类摄入量；②一定能量密度范     

1028例双美注射去除面部皱纹的近期临床效果分析

目的探讨双美（Sunmax）药物注射对面部不同部位除皱的近远期效果。方法2007年1月至2011年12月我院整彤美容科收治行面部除皱患者1028例，男236例，女792例，年龄21～72岁。全部患者应用双美进行面部除皱，根据药物注射部位的不同进行分组观察，在注射后当日、1个月、3个月、6个月、9个月比较不同组之间除皱的结果，综合分析双美注射除皱的近远期效果。根据药物注射部位分为：眉问川字皱纹、额部抬头纹、鼻唇沟皱纹、眼角鱼尾纹、鼻梁横纹进行分组观察。结果双美注射除皱后，各种皮肤皱纹凹陷均可以消失；注射后1个月效果无减退，皱纹不产生；3～6个月，除皱效果仍可与注射当日持平，9个月时，仅额部抬头纹和眼角鱼尾纹处出现轻微效果减退。结论应用双美进行注射去除面部皱纹是一项新兴的技术，术后患者满意度高，是目前值得推广的注射除皱方法。     

The effect of increased longevity, produced by dietary restriction, on the neuronal population of area 17 in rat cerebral cortex

Area 17 of the brains of Sprague-Dawley derived rats, maintained on a limited ration of food to maintain their weights at the levels attained by two months of age, was compared with area 17 in control groups of rats fed ad lib. The oldest rats in the diet restricted group were sacrificed at 46 and 48 months of age, by which time their life spans had been extended about 12 months beyond the oldest age that rats fed ad lib achieve, for only few of the latter live as long as 33 months. In this study, the rats which were compared consisted of two groups of ad lib fed rats, one 3 and 6 months of age, and the other 33 months old, and two groups of diet restricted rats, one 26 months old and the other 46 to 48 month old rats (designated as 47 month old rats). Two indices were used to assess whether age affects the volume of area 17. One, the number of clusters of apical dendrites of layer V pyramidal cells per unit area of tangential sections, was the same in all groups, indicating that the lateral spread of area 17 did not alter with age. However, the other index, the thickness of area 17, did change with age, for area 17 was significantly thinner in the 47 month old diet restricted rats than in the other three groups. It was also found that the number of neuronal profiles in strips of sections passing through the entire depth of area 17 is decreased in the 47 month old rats, indicating that neurons had been lost from their cortices. This decrease in the number of neuronal profiles in the 47 month old rats was not due to nuclear shrinkage since the sizes of neuronal nuclei were not significantly different in the older ad lib and diet restricted rats. Determinations of neuronal packing densities in layers II/III, IV, V and VIa suggest that neurons are most frequently lost from the deeper cortical layers of the 47 month old rats, and in these layers large vacuolated spaces, the sizes of neuronal cell bodies, have been encountered. It is suggested that these spaces represent places from which neurons have been lost. It is concluded, therefore, that neurons are lost from area 17 in rats whose longevity is increased by diet restriction.     

Lifelong immunization with human beta-amyloid (1-42) protects Alzheimer's transgenic mice against cognitive impairment throughout aging

Although both active and passive beta-amyloid (Abeta) immunotherapy have been shown to protect against or lessen cognitive impairment in various Alzheimer's transgenic mouse lines, these studies have focused on a single task and involved standard statistical analysis. Because Alzheimer's disease impacts multiple cognitive domains, the current study employed an extensive behavioral battery and multimetric analysis therein to determine the impact of Abeta immunization given throughout most of adult life (from 2-16 1/2 months of age) to APP+PS1 transgenic mice. At both adult (4 1/2-6 month) and aged (15-16 1/2 month) test points, the same 6-week behavioral battery was administered. Results indicate that Abeta immunotherapy partially or completely protected APP+PS1 mice at both test points from otherwise impaired performance in a variety of tasks spanning multiple cognitive domains (reference learning/memory, working memory, search/recognition). At both adult and aged test points, the cognitive benefits of Abeta immunotherapy were evident even when behavioral measures were analyzed collectively (as "overall" performance) through discriminant function analysis. Since behavioral protection at the 15-16 1/2 month test point occurred without a decrease in (or correlation to) Abeta deposition, the mechanism of Abeta immunotherapy's action most likely involves neutralization/removal of small Abeta oligomers from the brain. However, in factor analysis performed at this aged test point, brain Abeta deposition measures loaded heavily with key cognitive measures. Collectively, our results suggest that the entire process of Abeta deposition deleteriously impacts cognitive performance and that Abeta-based preventative strategies can provide long-term cognitive benefits extending well into older age.     

肠源性内毒素血症在大鼠代谢综合征相关疾病发生发展中的作用及其机制

目的: 探讨肠源性内毒素血症(IETM)在代谢综合征(MS)相关疾病发生发展中的作用及可能的分子机制。方法: 将64只大鼠随机分为8组,分别是3月正常对照组(3C)、3月高糖高脂组(3H)、6月正常对照组(6C)、6月高糖高脂组(6H)、9月正常对照组(9C)、9月高糖高脂组(9H)、12月正常对照组(12C)和12月高糖高脂组(12H)。测定血浆脂多糖(LPS)、游离脂肪酸(FFA)、肿瘤坏死因子α(TNF-α)、C反应蛋白(CRP)、巨噬细胞趋化蛋白-1(MCP-1)、空腹血糖(FPG)和空腹胰岛素(FINS),并计算胰岛素抵抗指数(HOMA-IR)。免疫组化方法观察脂肪组织、肝组织和胰腺组织CD68表达水平;Western blotting测定肝组织、胰腺组织中JNK1、p-JNK1、NF-κB p65、IκB、GRP78蛋白表达水平。结果: 与正常对照组相比,各阶段高糖高脂组的大鼠血清LPS、TNF-α、CRP、MCP-1、FPG、FINS和HOMA-IR的水平都升高,其差异有统计学意义;免疫组化结果显示各阶段高糖高脂组大鼠的脂肪组织、肝组织和胰腺组织CD68表达水平明显升高,且随时间推移加重;各阶段高糖高脂组的大鼠肝组织p-JNK1、NF-κB p65表达显著高于正常组,而IκB表达显著低于正常组;高糖高脂组的大鼠胰腺组织p-JNK1和NF-κB p65的表达于第6个月开始升高,第9个月、第12个月达到高峰,而IκB的表达也于第6个月开始降低。结论: IETM可能在MS相关的代谢性疾病中发挥着重要的作用,NF-κB、JNK和GRP78信号可能参与了上述过程。     

Arousal and ventilatory responses to hypoxia in sleeping infants: effects of maternal smoking

Our aim was to determine whether maternal cigarette smoking affects arousal and ventilatory responses to hypoxia in infants. Infants born to non-smoking (NS, n = 15) and smoking mothers (SM, n= 9) were studied at 2-5 weeks, 2-3 and 5-6 months. Ventilatory responses to 15% O(2) were determined preceding arousal. At each age and in both groups, infants aroused more frequently and earlier to hypoxia in active sleep (AS) than quiet sleep (QS). Arousal latency was longer in SM infants (in QS) at 5-6 months (P < 0.05). Baseline respiratory parameters were not different between groups, except that, at 2-3 months, SM infants had higher SP(O2) during AS than NS infants. Maternal smoking did not affect ventilatory responses preceding hypoxia-induced arousal in either sleep-state at any age. We conclude that mild hypoxia stimulates ventilation and arousal in infants up to 6 months and that arousability is depressed in SM infants at 5-6 months; however, ventilatory responses preceding arousal are not adversely affected by smoking.     

Reduced aminergic synthesis in the hypothalamus of the infertile,genetically diabetic (C57BL/KsJ-db/db) male mouse

Summary Diabetes mellitus is commonly associated with reproductive neuroendocrinopathy in both humans and animal models for the disease. Diabetes-associated reproductive failure in the male is a result of multilevel dysfunction within the hypothalamo-pituitary-testicular axis. In view of the known effects of diabetes on hypothalamic gonadotropin-releasing hormone (GnRH) and gonadotropins in chemically-induced animal models for diabetes, we examined hypothalamic aminergic activities (important to the regulation of GnRH release), circulating gonadotropin levels and testicular morphology in the infertile, genetically diabetic (C57BL/KsJ-db/db) male mouse. Groups of 2–5 month old (average age: 3.4 months) and 6–11 month old (average age: 8.8 months) diabetic mice were compared with age-matched non-diabetic (C57BL/KsL-+/?) male mice. Diabetic mice in both age groups were markedly obese and hyperglycemic. Hypothalamic serotonin synthesis was inhibited in the preoptic area-anterior hypothalamus (POA-AH) in both 2–5 month old and 6–11 month old diabetic mice as well as in the mediobasal hypothalamus-median eminence (MBH-ME) of 6–11 month old diabetic mice. Catecholamine synthesis (norepinephrine and dopamine) was reduced in the POA-AH of 2–5 month old diabetic mice and in the MBH-ME of 6–11 month old mice. These aminergic changes were associated in 2–5 month old diabetic mice with reduced circulating levels of LH and in 6–11 month old diabetic mice, of both LH and FSH. In 6–11 month old diabetic mice, testes were characterized by a thickened tunica albuginea, numerous Sertoli cells and the near absence of any spermatogenic cells. The epididymis from these diabetic mice was devoid of spermatozoa. In considering the central role played by these hypothalamic amine systems in regulating GnRH release and thus reproductive function, these results suggest, at least in part, an explanation for the infertility associated with the genetically diabetic male mouse.     

A quantitative histochemical study of 5'-nucleotidase activity in rat liver after ischaemia

The lead salt method of Wachstein and Meisel15 has been applied using incubation media containing polyvinyl alcohol for the localization and quantification of 5'-nucleotidase (E.C.3.1.3.5) activity in cryostat sections from rat liver after ischaemia in vitro and ischaemia in vivo followed by different periods of re-perfusion. 5'-Nucleotidase activity at the bile canaliculi, especially in the pericentral areas, had already decreased after 60 min of ischaemia in vitro, although the total activity as measured densitometrically was not changed. After 120-240 min of ischaemia, a significant decrease of the total 5'-nucleotidase activity was found. At that stage, signs of irreversible cell damage were recognized. Short periods of re-perfusion (1 h) after ischaemia in vivo induced a decreased bile canalicular 5'-nucleotidase activity throughout the entire liver, but a restoration after longer periods of re-perfusion was observed (5, 24, and 48 h). Necrotic areas recognized by a decreased lactate dehydrogenase activity after all periods of re-perfusion showed decreased total 5'-nucleotidase activities. A correlation was observed between the decrease in bile canalicular 5'-nucleotidase activity and the disappearance of microvilli of the bile canaliculi. It is concluded that a decrease in the bile canalicular 5'-nucleotidase activity can be used as a very sensitive marker for ischaemic liver cell damage. Assessment of the irreversibility of the cell injury has to be determined using additional parameters such as a decreased lactate dehydrogenase activity.     

The importance of B-cells and ecto-5'nucleotidase in Mycoplasma fermentans infection and the relevance to rheumatoid arthritis

The aim of this work was to discover if Mycoplasma fermentans, which is known to infect B cells, could be the cause of the raised ecto-5'-nucleotidase observed in the synovial fluid of rheumatoid arthritis patients. The ecto-5'-nucleotidase activity in the patients' serum has been shown to correlate with the erythrocyte sedimentation rate and DNA from the mycoplasma has been found in the synovial fluid. B lymphoblastoid cell lines were exposed to 16 strains of Mycoplasma fermentans and their ecto-5'-nucleotidase, CD73, was measured both biochemically and by mouse antibodies to human ecto 5'-nucleotidase using the fluorescence activated cell sorter. The type strain, PG 18, did not grow with the B cells. Some of the mycoplasma strains (9/15) increased the cellular ecto-5'-nucleotidase activity from twice to 17 fold, and usually showed 5'-nucleotidase activity themselves. At least one strain, M106, induced human 5'-nucleotidase on the normally 5'-nucleotidase negative Daudi and Raji Burkitt's lymphoma cell lines, and increased sevenfold the 5'-nucleotidase on the monocyte/macrophage cell line THP-1. Growing the cells in aged medium increased the level of mycoplasma infection. This mycoplasma-induced enzyme showed a conformational change and an increase in activity with a glycosylation change involving mannose groups. The other group of strains, mostly of respiratory or cell culture origin, usually did not have any 5'-nucleotidase of their own and decreased the B-cell enzyme activity by about half. Electron microscopy and flow cytometry showed that the strain M106 was filamentous and could be found inside the B-cells. The 5'-nucleotidase-inducing strains of M. fermentans may be important in the aetiology of rheumatoid arthritis.     

关节镜下Fiber Tape环形内固定治疗前交叉韧带胫骨止点撕脱性骨折

文题释义： 前交叉韧带胫骨止点撕脱骨折：为前交叉韧带胫骨髁间嵴在遭受剧烈运动或暴力作用下发生的撕脱骨折,属关节内损伤。由1875年Poncet首次描述,早期常见于儿童的儿童型前交叉韧带撕裂,近年来发病率有所增高。骨折移位较大时造成的愈合畸形或不愈合容易导致前交叉韧带松弛甚至丧失功能,最终导致膝关节功能障碍或不稳。 Fiber Tape：型号AR-7237-7,由Arthrex公司提供。为不可吸收、宽2 mm扁平超高分子量聚乙烯与聚酯编织的缝合线,中部为扁平带状,逐渐过渡到两端的圆柱状结构,具有一定柔软性及相当的韧性,常被应用到肩袖修复或肩锁关节重建。具有良好的手感和打结能力,滑结前进顺利,简化了关节镜打结程序。多个独立的科学研究证明其在断裂强度、刚度、结强度和结滑移方面更具优势,但延伸率要低得多。广泛的生物相容性、动物和临床试验结果证明其具有与标准聚酯缝合线相当的生物相容性特征。 背景：前交叉韧带胫骨止点撕脱性骨折需尽早行手术复位内固定,目前临床治疗方案中常用切开复位(可吸收螺钉、空心钉、钢丝、钛缆等)内固定,创伤较大,术后并发症多。而关节镜下行前交叉韧带下止点骨折复位弹性(缝线)内固定具有微创、术野清晰、固定准确性高、并发症少、骨折复位愈合好、符合生物力学要求、关节功能康复快等优点,但也有强度不够、骨块切割等缺点。 目的：比较关节镜下Fiber Tape环形固定与开放内固定治疗前交叉韧带下止点撕脱骨折的疗效。 方法：收集2017年1月至2018年12月上海中冶医院骨科收治的32例前交叉韧带下止点撕脱骨折患者,所有患者对治疗方案均知情同意,且得到医院伦理委员会批准。根据手术方法分成2组,微创组17例采用关节镜下Fiber Tape环形固定治疗;开放组15 例采用开放手术骨折复位(空心拉力螺钉、钛缆、钢丝等)内固定治疗。记录所有患者手术时间、出血量、术后并发症情况;于术前及术后第1,6个月记录膝关节活动范围、Lysholm评分及国际膝关节评分委员会评分,摄X射线片评价骨折复位愈合情况。 结果与结论：①所有患者获得随访,时间6-13个月;②2组患者年龄组成、骨折类型、受伤原因、术前评分差异无显著性意义;③术后X射线片复查骨折均得到满意复位,术后未出现神经、血管损伤、骨折移位情况,术后6个月骨折均愈合良好;④2组手术时间、术后并发症发生率差异无显著性意义,2组术中出血量差异有显著性意义(P=0.036);⑤膝关节活动度：2组患者术后1个月膝关节活动度显著大于术前(P < 0.05),术后6个月膝关节活动度显著大于术后1个月(P < 0.05);术后1,6个月微创组膝关节活动度显著大于开放组(P < 0.05);⑥Lysholm膝关节功能评分及国际膝关节评分委员会评分：2组患者术后1个月Lysholm 膝关节功能评分及国际膝关节评分委员会评分均显著高于术前(P < 0.05),术后6个月评分均显著高于术后1个月(P < 0.05);术后1,6个月微创组评分均显著高于开放组(P < 0.05);⑦提示2组患者经过手术干预膝关节屈伸活动大部分恢复,且随时间延长恢复程度越高。与开放内固定(空心拉力螺钉、钛缆、钢丝等)相比,关节镜下Fiber Tape环形固定治疗前交叉韧带下止点撕脱骨折的出血更少,创伤更小,关节功能恢复时间更短,恢复程度更高。 ORCID: 0000-0003-1711-8964(李广峰) 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

Seroepidemiological study of human herpesvirus-6 and -7 in children of different ages and detection of these two viruses in throat swabs by polymerase chain reaction

The presence of human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7) in throat swabs of 62 children of different age groups (group I, ages 0–5 month; group II, ages 6–11 months, group III, ages 12–23 months, group IV, age 2–8 years) and 28 adults was detected by polymerase chain reaction. The detection rate of HHV-6 DNA was the highest (87%) in children aged 1-year-old and decreased with age, whereas the detection rate of HHV-7 increased with age and reached a maximum in adults. HHV-6B was detected in almost all samples except for two children who secreted only HHV-6A. When the antibody prevalence was determined in the four groups of children, HHV-6 antibody was detected in 8/12 (66.7%), 10/12 (83.3%), 15/16 (93.8%), and 13/14 (92.9%), respectively. Antibody to HHV-7 in these groups was detected in 6/12 (50.0%), 4/12 (33.3%), 12/16 (75.0%), and 13/14 (92.9%), respectively. Detection of HHV-6 DNA in throat swabs of triplets who had the sequential onset of exanthem subitum was attempted by using samples sequentially collected from these children after the onset of the disease in the first patient. HHV-6 DNA with high copy numbers was detectable during the acute and convalescent phases of the disease in all patients, but no DNA was detected in samples collected before the onset of disease. © 1996 Wiley-Liss, Inc.     

Calmodulin regulation of the cholinergic receptor in the rat heart during ontogeny and senescence

The contents of calmodulin and cholinergic muscarinic receptor binding sites in the hearts of fetal, adult and aged rats have been examined. A biphasic pattern of calmodulin development was observed. A relatively high level of calmodulin appeared on gestational days 14-15 followed by a steady but significant decrease at birth and during the first week of postnatal life. The level of calmodulin then increased significantly during the first month followed by a decrease at 6 and 26 months of age. Calmodulin contents were significantly higher in the atrium than in the ventricle in the age groups of 1-26 months. The number of [3H]QNB binding sites showed a steady increase during the gestational periods studied, reaching a peak at 9 days after birth and followed by a significant (P less than 0.05) decline at 6 and 26 months of age. A good correlation between the levels of [3H]QNB binding and calmodulin was observed from day 9 of the postnatal period to 26 months of age. In the presence of calcium, calmodulin induced a dose-dependent receptor binding loss in the hearts of postnatal, young adult and aged rats under phosphorylating conditions. These findings support the suggestion that calmodulin may regulate cholinergic functions during ontogeny and senescence.