Differential influences of exercise intensity on information processing in the central nervous system

The influence of exercise intensity on information processing in the central nervous system was investigated using P300 and no-go P300 event-related potentials. Twelve subjects (22–33 years) performed a go/no-go reaction time task in a control condition, and again after high-, medium-, and low-intensity pedaling exercises. Compared to the control condition, P300 amplitude decreased after high-intensity pedaling exercise and increased after medium-intensity pedaling exercise. There was no change after low-intensity pedaling exercise. These results suggested that the amount of attentional resources devoted to a given task decreased after high-intensity exercise and increased after medium-intensity exercise. The findings also suggest that changes in P300 amplitude are an inverted U-shaped behavior of differences in exercise intensity. In addition, no-go P300 amplitude showed the same changes as P300 amplitude at different exercise intensities. This indicates that differences in exercise intensity influenced not only the intensity of processing the requirement for a go response, but also processing of the need for a no-go response. It is concluded that differences in exercise intensity influenced information processing in the CNS.     

Unusual Presentation of ‘U-Shaped’ Impacted Maxillary Central Incisor with Intranasal Root: Successful Surgical Management

Background

Dilacerations is a tooth deformity characterized by an angulation between crown and root causing non-eruption of the tooth. It generally occurs following trauma to the deciduous dentition apices of which lie close to the permanent tooth buds. According to Neville, maxillary and mandibular incisors contribute only approximately to 1% of the incidence of dilacerated teeth.

Case Details

A 15 year old male patient reported with chief complaint of missing anterior teeth in the left side of maxillary arch. Radiographic evaluation showed impacted maxillary left central incisor. The radiograph depicted very unusual extreme curve in the root of the same tooth giving it characteristic U-morphology. The root of this tooth was curving into the nasal cavity. Due to extreme curve, surgical removal was suggested by orthodontist. Surgically removing this highly placed tooth with apex into nasal cavity was a surgical challenge. This was done effectively by removing the tooth under local anesthesia itself.

Conclusion

U-shaped morphology in single rooted tooth is observed very rarely. This root curvature predisposes to fracture of root during surgical removal. Proper surgical protocol is to be followed during surgical removal of a tooth with such extreme root curvature to prevent fracture of the root and accidental displacement of the tooth into nasal cavity.     

U-Shaped Dose Response in Behavioral Pharmacology: Historical Foundations

This article assesses the historical foundations of U-shaped dose-responses in behavioral pharmacology and toxicology with particular emphasis on schedules of reinforcement. Quantitative features of the drug dose response, which are consistent with the hormetic dose response model, are detailed along with possible mechanistic foundations to account for low-dose stimulation and high-dose inhibition responses. The article provides a reinterpretation of the biphasic dose response in the fixed interval (FI) schedule of reinforcement.     

Uric Acid Excretion with Increasing Plasma Glucose Concentration (Pregnant and Non-Pregnant Cases)

In optimal concentration, N-ethyl-urethan enhances urokinase-induced caseinolytic activity in human plasma mainly through an irreversible denaturation of inhibitors and more effectively than o-thymotic-acid-Na.

In estimation of plasminogen-plasmin in human plasma, the use of N-ethyl-urethan was found to be a simpler means of denaturating inhibitors than acidification, but only partial removal of inhibitory activity was obtained. Because the presence of casein protects against the loss of proteolytic capacity in plasma, N-ethyl-urethan should be mixed with the casein and not directly with the plasma.     

改良长U形空心椎弓根钉及配套锁定插销的力学分析

目的 比较改良长U形空心椎弓根钉及配套锁定插销与传统长U形空心椎弓根钉的机械性能,验证其力学稳定性.方法 准备改良椎弓根钉及配套插销(观察组)与传统空心椎弓根钉(对照组)各10套,分别通过机械测定实验和有限元方法比较两组的屈服载荷、刚度等力学数据.结果 在机械性能单点弯曲静态测试和有限元分析中,观察组刚度、屈服载荷都较...     

Non-Monotonic Dose Responses in Studies of Endocrine Disrupting Chemicals: Bisphenol A as a Case Study

Non-monotonic dose response curves (NMDRCs) have been demonstrated for natural hormones and endocrine disrupting chemicals (EDCs) in a variety of biological systems including cultured cells, whole organ cultures, laboratory animals and human populations. The mechanisms responsible for these NMDRCs are well known, typically related to the interactions between the ligand (hormone or EDC) and a hormone receptor. Although there are hundreds of examples of NMDRCs in the EDC literature, there are claims that they are not ‘common enough’ to influence the use of high-to-low dose extrapolations in risk assessments. Here, we chose bisphenol A (BPA), a well-studied EDC, to assess the frequency of non-monotonic responses. Our results indicate that NMDRCs are common in the BPA literature, occurring in greater than 20% of all experiments and in at least one endpoint in more than 30% of all studies we examined. We also analyzed the types of endpoints that produce NMDRCs in vitro and factors related to study design that influence the ability to detect these kinds of responses. Taken together, these results provide strong evidence for NMDRCs in the EDC literature, specifically for BPA, and question the current risk assessment practice where ‘safe’ low doses are predicted from high dose exposures.     

Biomechanical effects of cervical arthroplasty with U-shaped disc implant on segmental range of motion and loading of surrounding soft tissue

Purpose

Various design concepts have been adopted in cervical disc prostheses, including sliding articulation and standalone configuration. This study aimed to evaluate the biomechanical effects of the standalone U-shaped configuration on the cervical spine.

Methods

Based on an intact finite element model of C3–C7, a standalone U-shaped implant (DCI) was installed at C5–C6 and compared with a sliding articulation design (Prodisc-C) and an anterior fusion system. The range of motion (ROM), adjacent intradiscal pressure (IDP) and capsular ligament strain were calculated under different spinal motions.

Results

Compared to the intact configuration, the ROM at C5–C6 was reduced by 90 % after fusion, but increased by 70 % in the Prodisc-C model, while the maximum percentage change in the DCI model was 30 % decrease. At the adjacent segments, up to 32 % increase in ROM happened after fusion, while up to 34 % decrease occurred in Prodisc-C model and 17 % decrease in DCI model. The IDP increased by 11.6 % after fusion, but decreased by 5.6 and 6.3 % in the DCI and Prodisc-C model, respectively. The capsular ligament strain increased by 147 % in Prodisc-C and by 13 % in the DCI model. The DCI implant exhibited a high stress distribution.

Conclusions

Spinal fusion resulted in compensatory increase of ROM at the adjacent sites, thereby elevating the IDP. Prodisc-C resulted in hyper-mobility at the operative site that led to an increase of ligament force and strain. The U-shaped implant could maintain the spinal kinematics and impose minimum influence on the adjacent soft tissues, despite the standalone configuration encountering the disadvantages of high stress distribution.     

脊柱后路2种内固定技术治疗胸腰椎爆裂骨折的疗效评估

目的比较KumaFix脊柱后路钉棒系统和传统后路U型钉棒系统短节段内固定治疗胸腰椎爆裂骨折的临床疗效。方法纳入自2011-01—2014-01短节段椎弓根钉内固定联合伤椎椎弓根植骨治疗的120例胸腰椎爆裂骨折,60例采用KumaFix脊柱后路钉棒系统内固定(KumaFix组),60例采用传统后路U型钉棒系统内固定(U型钉组)。结果 120例均获得随访25~60个月,平均35.6个月。末次随访时,KumaFix组9例(15.0%)出现影像学邻近节段退变(ASD),U型钉组29例(48.3%)出现影像学ASD;KumaFix组影像学ASD发生率低于U型钉组,差异有统计学意义(P0.05)。末次随访时KumaFix组改良Prolo评分为优的例数明显多于U型钉组,差异有统计学意义(P0.05)。KumaFix组与U型钉组术前、术后即刻、术后1年、末次随访时椎体前缘高度比(AVHR)、矢状位后凸角(KA)和椎管横截面积比值(CSR)比较差异无统计学意义(P0.05)。结论 KumaFix脊柱后路钉棒系统可以实现椎体渐进、平稳复位,有利于经伤椎椎弓根植骨,降低了邻近节段退变的发生率,是治疗胸腰椎爆裂骨折的有效方法。     

机器人辅助腹腔镜体内原位U形回肠新膀胱术的临床疗效观察及尿动力分析

目的探讨采用da Vinci Xi机器人系统完成机器人辅助腹腔镜下根治性膀胱切除（RARC）加体内构建原位U形回肠新膀胱术的临床疗效,并结合术后尿动力分析评价该术式对排尿的影响及可能机制。 方法以2020年6月至2021年3月连续进行的8例机器人辅助腹腔镜下根治性膀胱切除+体内原位U形回肠新膀胱术患者为研究对象,其中男7例,女1例,年龄63（18）岁,极高危非肌层浸润膀胱癌1例,肌层浸润性膀胱癌7例,术后随访时间为3~12个月。记录随访期间患者的尿控恢复、分肾功能、上尿路影像学结构改变以及肿瘤学预后。 结果8例手术均成功完成,并发症发生率37.5%,术后3个月日间完全尿控率87.5%,夜间功能性尿控率75.0%,术后6个月尿动力分析示：最大尿流率和平均尿流率分别为19.8（3.97）ml/s、5.05（0.94）ml/s,最大尿道压81.5（28.75）cm H₂O,新膀胱顺应性26.5（12.75）ml/cm H₂O。 结论RARC术后实施体内原位U形回肠新膀胱术是可行的,具有可重复性,是一种疗效确切、尿控恢复理想的膀胱根治性切除术后新膀胱替代方案。