A study of surgeons’ postural muscle activity during open, laparoscopic, and endovascular surgery

Background  

Different surgical procedures impose different physical demands on surgeons and high prevalence rates of neck and shoulder pain have been reported among general surgeons. Past research has examined electromyography in surgeons mainly during simulated conditions of laparoscopic and open surgery but not during real-time operations and not for long durations. The present study compares the neck-shoulder muscle activities in three types of surgery and between different surgeons. The relationships of postural muscle activities to musculoskeletal symptoms and personal factors also are examined.     

Expression and localization of Smadl, Smad2 and Smad4 proteins in rat testis during postnatal development

Aim: To study the expression and regulation of Smadl, Smad2 and Smad4 proteins (intracellular signaling molecules of transforming growth factor-β family) in rat testis during postnatal development. Methods: The whole testes were collected from SD rats aged 3, 7, 14, 28 and 90 (adult) days. The cellular localization and developmental changes were examined by immunohistochemistry ABC method with the glucose oxidase-DAB-nickel enhancement technique. Quantitative analysis of the immunostaining was made by the image analysis system. The Smads proteins coexistence in the adult rat testis was tested by the double immune staining for CD14-Smad4 and Smad2-Smad4. The protein expression of Smad during rat testicular development was examined by means of Western blots. Results: Smadl, Smad2 and Smad4 were present throughout testicular development. The immunostaining of Smadl and Smad2 were present in spermatogenic cells. A positive immunoreactivity was located at the cytoplasm, but the nucleus was negative. Smadl wa     

Metabolic, coagulative, and hemodynamic changes during intestinal transplant: good predictors of postoperative damage?

BACKGROUND: Analysis of intraoperative changes of metabolic, hemodynamic, and coagulative parameters is useful to detect early ischemia-reperfusion damage after intestinal transplant. METHODS: The objective of our study is to correlate the histological damage at the end of transplant in relation to the intraoperative changes after reperfusion. The histological aspect was graded according to Park's classification at the end of the surgical procedure with biopsies of the graft. Patients were divided into two groups according to the presence or absence of histological damage of the small bowel wall: group A (normal mucosa/minimal damage: Park's grades 0-1) and group B (mucosal damage: Park's grades 2-8). RESULTS: Significant hemodynamic, metabolic, and coagulative disorders were observed in group B. Consequently, these disorders are thought to be early indicators of graft damage. CONCLUSIONS: Actual monitoring procedures used for postoperative graft surveillance remain paramount in detecting postoperative intestinal dysfunction, but the indicators described in this paper could represent a further help in intraoperative and postoperative management.     

Changes of osteocalcin and IGF-I during bone lengthening

Bonelengtheningisamuchmorecomplexprocesscomparedwiththeprocessoffracturehealing.Inthisprocessbonechangesinvariousaspects,morphologicallyandphysico chemically,andat differentintervalsanddifferentlevelsoflengthening, fromgrosstoultrastructural.Themajorityofstudies havebeenfocusedonclinicalorhistologicalchanges andmorphologicalaspects.Essentiallywehavenot paidmuchattentioninascertainingthechanges,ifit hasany,whichoccurinbasicphysicalandchemical parametersofboneatdifferenttimeorregion.As evidences…     

Wnt6, Wnt10a and Wnt10b inhibit adipogenesis and stimulate osteoblastogenesis through a β-catenin-dependent mechanism

Wnt10b is an established regulator of mesenchymal stem cell (MSC) fate that inhibits adipogenesis and stimulates osteoblastogenesis, thereby impacting bone mass in vivo. However, downstream mechanisms through which Wnt10b exerts these effects are poorly understood. Moreover, whether other endogenous Wnt ligands also modulate MSC fate remains to be fully addressed. In this study, we identify Wnt6 and Wnt10a as additional Wnt family members that, like Wnt10b, are downregulated during development of white adipocytes in vivo and in vitro, suggesting that Wnt6 and/or Wnt10a may also inhibit adipogenesis. To assess the relative activities of Wnt6, Wnt10a and Wnt10b to regulate mesenchymal cell fate, we used gain- and loss-of function approaches in bipotential ST2 cells and in 3T3-L1 preadipocytes. Enforced expression of Wnt10a stabilizes β-catenin, suppresses adipogenesis and stimulates osteoblastogenesis to a similar extent as Wnt10b, whereas stable expression of Wnt6 has a weaker effect on these processes than Wnt10a or Wnt10b. In contrast, knockdown of endogenous Wnt6 is associated with greater preadipocyte differentiation and impaired osteoblastogenesis than knockdown of Wnt10a or Wnt10b, suggesting that, among these Wnt ligands, Wnt6 is the most potent endogenous regulator of MSC fate. Finally, we show that knockdown of β-catenin completely prevents the inhibition of adipogenesis and stimulation of osteoblast differentiation by Wnt6, Wnt10a or Wnt10b. Potential mechanisms whereby Wnts regulate fate of MSCs downstream of β-catenin are also investigated. In conclusion, this study identifies Wnt10a and Wnt6 as additional regulators of MSC fate and demonstrates that mechanisms downstream of β-catenin are required for Wnt6, Wnt10a and Wnt10b to influence differentiation of mesenchymal precursors.     

Should normothermia be restored and maintained during resuscitation after trauma and hemorrhage?

BACKGROUND: Although hypothermia often occurs after trauma and has protective effects during ischemia and organ preservation, it remains unknown whether maintenance of hypothermia or restoring the body temperature to normothermia during resuscitation has any deleterious or beneficial effects on heart performance and organ blood flow after trauma-hemorrhage. METHODS: Male rats underwent laparotomy (i.e., induced trauma) and were exsanguinated to and maintained at a mean arterial pressure of 40 mm Hg until 40% of the maximum shed volume was returned in the form of Ringer's lactate. Body temperature decreased from approximately 36.5 degrees C to below 32 degrees C. The animals were then resuscitated with four times the volume of maximal bleedout with Ringer's lactate. In one group, body temperature was rewarmed to 37 degrees C during resuscitation. In another group, body temperature was maintained at hypothermia (32 degrees C) for 4 hours after resuscitation. In an additional group, the body temperature was kept at 37 degrees C during hemorrhage as well as during resuscitation. Left ventricle performance parameters such as maximal rate of left ventricular pressure increase and decrease (+/-dP/dt(max)) were measured up to 4 hours. Cardiac output and regional blood flow were determined by radioactive microspheres at 4 hours after the completion of resuscitation. RESULTS: The maintenance of normothermia during hemor. rhage or prolonged hypothermia after resuscitation depressed the left ventricular performance parameters, cardiac output, and regional blood flow in various organs. Rewarming the body to normothermia during resuscitation, however, significantly increased heart performance, cardiac output (from hypothermia 16.2 +/- 1.4 to 22.3 +/- 1.4 mL/min per 100 g body weight,p < 0.05) and total hepatic blood flow (from hypothermia 117.5 +/- 5.3 to 166.0 +/- 9.3 mL/min per 100 g tissue, p < .05). CONCLUSION: Our data indicate that restoration of normothermia during resuscitation improves cardiac function and hepatic blood flow compared with hypothermia.     

Ultrastructural observations on nucleolar changes during mouse spermiogenesis

When applying a new silver staining technique on developing mouse spermatids, it could be shown that strong argyrophilia in the "padlock" like nucleolus of very early spermatids is confined to its fibrillar and granular component, whereas the fibrillar centre is devoid of silver. During further steps the granular component disappears together with the fibrillar centre. The last remaining nucleolar part, the silver positive fibrillar component disintegrates at the beginning of nuclear elongation. Instead of it clusters of coiled fibers bordered with granules of approximately 40-60 nm in diameter, both silver positive, appear in the nucleoplasm. As chromatin condensation proceeds, these silver positive structures, now intimately attached to the centrally occurring focus of condensing chromatin decrease more and more in size and density. In later stages accumulations of silver positive material will appear in the posterior region of the nucleus, will leave it, and stays as silver positive "juxtanuclear body" in the nuclear pocket formed by the redundant nuclear envelope. As spermatid development continues, the "juxtanuclear body" disappears together with the nuclear pocket. The small silver positive fibrous clusters disintegrate too so that the mature sperm only contains the space in which they formerly existed, now called "nuclear vacuole". A possible connection between silver staining pattern and RNA synthesis is discussed.     

Cellular localization of GABA and GABAB receptor subunit proteins during spermiogenesis in rat testis

The GABAergic system, a major inhibitory regulator in the central nervous system, may also play important roles in peripheral nonneuronal tissues and cells. Recent studies showed that GABAB receptor is expressed in testis and sperm. To understand the role of the GABAergic system in spermiogenesis, we examined cellular localization of GABA and GABAB receptor subunits in rat spermatids by immunocytochemistry. Immunoreactivity for GABA was detected around acrosomal granules of spermatids during the Golgi and cap phases. GABAB1 immunoreactivity was observed in the acrosomal vesicle of spermatids in Golgi phase, and during cap phase, this reactivity expanded to the entire region of the acrosome covering the nuclear membrane. The level of reactivity decreased gradually with maturation of spermatids. In contrast, GABAB2 immunoreactivity was not observed in spermatids during Golgi phase but was detected in the equatorial region during cap phase. Both GABA immunoreactivity and GABAB2 immunoreactivity were transferred to the residual cytoplasm during the release of spermatozoa. Electron microscopic immunocytochemistry revealed that, during cap phase, GABA and GABAB1 were distributed within the whole acrosomal vesicle but not in the acrosomal granule. GABAB2 immunoreactivity was observed in the narrow space between the inner acrosomal and nuclear membrane and was limited to the equatorial region of the spermatid head. These results indicate that the GABAergic system might be involved in regulation of spermiogenesis.     

谷胱甘肽硫转移酶基因多态性与精子形成的研究进展

精子发生受到诸多有序基因的表达与调控,这些特异基因的遗传多态性可能影响精子的发生。谷胱甘肽硫转移酶是一组多功能同工酶,属于II相反应代谢的超家族酶系,其通过催化还原型谷胱甘肽与亲电物质发生轭合反应,降低该亲电物质的活性、加速其排泄,达到解毒的效果。研究发现,谷胱甘肽硫转移酶基因多态性与精子发生可能存在密切关系。     

隐睾及睾丸固定术后对大鼠生精能力的影响

目的 观察隐睾及睾丸固定术后对睾丸生精能力的影响.方法 通过手术方法对80只SD大鼠制作单侧隐睾模型,随机分为10组,其中4组(每组10只)于隐睾术后7、14 d切取患侧睾丸组织,6组于隐睾术后7、14d行睾丸固定术,分别于术后2、4、6周取材.将所取得的睾丸组织称重后行流式细胞仪检测其细胞凋亡率和各生精细胞百分比以及组织中B淋巴细胞/白血病-2( bcl-2)和bax基因表达量.结果 隐睾睾丸重量明显下降,隐睾组1C细胞(7d组:10.61 ±1.10,14d组:11.79 ±0.91)较对照组降低(16.48±1.60,P＜0.05)、4C细胞也明显降低,而2C细胞(7d组:40.41±2.93,14 d组:51.41±6.45)较对照组增加(30.17±3.24,P＜0.05).隐睾各组生精细胞凋亡率(7d组:14.9±1.26,14 d组:6.90±0.96)高于正常对照组(2.50±0.44,P＜0.01),而睾丸复位固定术后各组生精细胞凋亡率均下降(P＜0.05).隐睾7、14 d睾丸中bc1-2蛋白表达量(7d组:4.68±0.47;14 d组:5.66 ±0.71)较对照组(7.47±1.01)降低而bax蛋白表达量(7d组:8.27±1.08;14 d组:6.26±0.21)较对照组(5.82 ±0.47,P＜0.05)升高,睾丸固定术后各组bcl-2蛋白表达量升高而bax蛋白表达量降低(P＜0.01).结论 隐睾可以使睾丸生精细胞凋亡增加,睾丸复位固定术后,睾丸生精功能可部分或全部恢复,其恢复程度和隐睾时间长短有关;bcl-2和bax表达在生精细胞凋亡的调控中起重要作用.     

人类生精细胞在培养过程中的分化与变形

目的 探讨体外培养条件下生精细胞向单倍体精子细胞分化以及精子细胞变形为精子的可能性.方法 对11例非梗阻性无精子症患者行睾丸活检,将其中9份具有生精细胞的活检标本在终浓度为50 U/L卵泡刺激素和1μmol/L睾酮的改良人输卵管液培养液中进行体外培养,对培养前及培养后24h标本中精子及其他细胞进行计数,计算各种细胞的比例.应用流式细胞仪对2例患者培养前和培养后24 h的细胞进行细胞倍体分析.结果 9例标本培养前精子比例为(17.7±8.9)％,培养24h后为(25.6±10.3)％,培养前后差异有统计学意义(P=0.004).2例细胞倍体分析结果显示,培养前可见4、2和1 n波峰,培养后4 n波峰消失,1 n波峰显著增宽和增高.结论 生精细胞体外培养可使生精细胞发生减数分裂,并使精子细胞向精子变形.     

负载miRNA-27b的BMSCs来源的外泌体治疗实验性骨关节炎

[目的]探讨负载miRNA-27b的间充质干细胞来源的外泌体(MSC-27b-Exos)对炎症环境下的软骨细胞的保护作用。[方法]体外利用10 ng/ml白介素-1β(IL-1β)建立软骨细胞炎症环境模型,采用超速离心法收集外泌体,分别以80μg/ml的MSC-27b-Exos,普通外泌体MSC-Exos、inhibitor沉默的MSC-27boff-Exos作用炎症环境下的软骨细胞,并设PBS处理为对照组,检测各处理组软骨细胞凋亡水平,Western blot检测软骨细胞中MMP-13,及凋亡蛋白Caspase的表达水平。体内实验:20只雄性SD大鼠随机分为4组,建立创伤性骨关节炎(post-traumatic osteoarthritis, PTOA)模型,分别注射等量的MSC-miR27b-Exos、MSC-miR27b~(off)-Exos,并设立单纯PBS组和假手术组,6周后取材,观察关节软骨形态;ELISA检测关节液中IL-1β、TNF-α的含量;免疫组化对比各组Ⅱ型胶原表达。[结果]体外实验中,MSC-27b-Exos组的软骨细胞增殖能力较MSC-miR27b~(off)-Exos组增强,较空白组明显旺盛(P0.05),在炎症环境下软骨细胞凋亡明显减弱(P0.05),MSC-27b-Exos组软骨细胞中cleave-Caspase-9水平降低(P0.05),cleave-Caspase-3水平降低(P0.05),MMP-13相对含量减少。SD大鼠体内实验显示, MSC-27bExos组对软骨缺损修复效果优于空白组和MSC-miR27b~(off)-Exos组。MSC-27b-Exos组关节液中IL-1β、TNF-α的含量低于空白组,明显低于MSC-27b~(off)-Exos组。[结论]在实验型SD大鼠PTOA模型中,利用MSC-27b-Exos关节腔内注射具有明显抗炎的作用和减缓关节软骨退行性变。     

Rab27a and Rab27b are involved in stimulation‐dependent RANKL release from secretory lysosomes in osteoblastic cells

The quantity of the receptor activator of NF‐κB ligand (RANKL) expressed at the cell surface of osteoblastic cells is an important factor regulating osteoclast activation. Previously, RANKL was found to be localized to secretory lysosomes in osteoblastic cells and to translocate to the cell surface in response to stimulation with RANK‐Fc‐conjugated beads. However, the in vivo significance of stimulation‐dependent RANKL release has not been elucidated. In this study we show that small GTPases Rab27a and Rab27b are involved in the stimulation‐dependent RANKL release pathway in osteoblastic cells. Suppression of either Rab27a or Rab27b resulted in a marked reduction in RANKL release after stimulation. Slp4‐a, Slp5, and Munc13‐4 acted as effector molecules that coordinated Rab27a/b activity in this pathway. Suppression of Rab27a/b or these effector molecules did not inhibit accumulation of RANKL in lysosomal vesicles around the stimulated sites but did inhibit the fusion of these vesicles to the plasma membrane. In osteoblastic cells, suppression of the effector molecules resulted in reduced osteoclastogenic ability. Furthermore, Jinx mice, which lack a functional Munc13‐4 gene, exhibited a phenotype characterized by increased bone volume near the tibial metaphysis caused by low bone resorptive activity. In conclusion, stimulation‐dependent RANKL release is mediated by Rab27a/b and their effector molecules, and this mechanism may be important for osteoclast activation in vivo. © 2011 American Society for Bone and Mineral Research.     

miR-27b对骨肉瘤MG63细胞生长的影响及其机制探讨

目的 探讨miR-27b对骨肉瘤MG63细胞生长的影响及其机制.方法 将体外培养的MG63细胞分为模拟物对照组、miR-27b模拟物组、抑制剂对照组和miR-27b抑制剂组,采用RT-PCR检测各组细胞中miR-27b的表达,MTT法检测细胞增殖活性,Transwell小室法检测细胞侵袭和迁移,流式细胞仪检测细胞凋亡....