生理环境中NiTi记忆合金腐蚀释放Ni离子的研究

目的研究pH值、Cl-浓度对医用NiTi形状记忆合金在不同模拟生理环境中的Ni2 腐蚀释放动力学过程的影响,同时对NiTi形状记忆合金Ni2 腐蚀释放机理进行分析探讨。方法在0.9%NaCl生理盐水、Hank’s模拟体液、Tyrode’s模拟血液三种模拟生理液中,pH值分别为2、5、8和10,恒温(37±1)℃下,进行静态挂片腐蚀试验,然后用最小二乘原理拟合试验曲线。结果Ni Ti形状记忆合金在Tyrode’s模拟血液中的Ni离子释放量最大,Hank’s模拟体液中次之,0.9%NaCl生理盐水中较低,Ni离子释放在前7天内呈现较快速度,之后趋于平缓;且Ni离子释放量随pH和Cl-的增大而增加。结论在Cl-浓度为正常条件0.14mol/L下,当体液在2≤pH≤10范围内波动时,NiTi记忆合金中Ni2 的腐蚀释放量在约3年内达不到Ni致敏的最低极限量,孔蚀是NiTi形状记忆合金在生理环境中主要的腐蚀机理。     

冶炼工人体内镍、铬负荷与脂质过氧化关系的研究

[目的]研究冶炼工人体内镍(Ni)、铬(Cr)负荷与自由基代谢变化的关系。[方法]以212名冶炼作业人员为接触组,以106名无Ni、Cr接触史的健康人作为非接触组,分别测定两组人员血清中Ni、Cr的含量作为体内负荷,同时测定两组人员血清中丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和谷胱甘肽硫转移酶(GST)水平,并将上述各项指标进行相关分析。[结果]接触组血清Ni、Cr平均水平分别为(O．15±0．04)和(0．26±0．03)μmol／L,血清SOD、GSH-Px和GST的活性分别为(161．22±29．26)、(116．42±20．16)和(38．36±10．06)U,MDA含量为(7．32±2．35)μmol／L;非接触组血清Ni、Cr平均水平分别为(0．07±0．05)和(0．08±0．04)μmol/L,血清中SOD、GSH-Px和GST的活性分别为(181．61±28．34)、(153．14±20．36)和(46．20±10．26)U,MDA含量为(4．35±1．26)μmol／L。对接触组与非接触组上述对应各项指标进行统计学分析,差异呈高度显著性(P<0．01)。将接触组人员以工龄分组比较,显示工龄≥10年组与工龄5～9年组比较,血清Ni、Cr平均水平和MDA含量均较高(P<0．05),而SOD、GSH-Px和GST活性均较低(P<0．05)。[结论]Ni、Cr具有增加体内脂质过氧化产物含量、降低机体的抗氧化能力的作用,增强Ni、Cr接触人群的氧化应激易感性。     

Effets tardifs des radiations ionisantes sur les tissus de la sphère otorhinolaryngologique

Numerous structures are included in the irradiated volume of patients presenting with head and neck cancer: skin, mucosa, bone, teeth, cartilage, muscles, salivary glands, etc. Curative intent treatment of such tumours requires aggressive approach which can lead to severe sequellae. These sequellae are in most cases dose-dependent and volume-dependent. However, an appropriate technique might decrease the severity of such sequellae. Details of these late changes are presented, including their pathophysiology, clinical syndromes, potential treatment, and prevention.     

硬膜外阻滞麻醉处理活跃期及胎头下降阻滞的临床研究

本文对56例活跃期或第二产程胎头下降阻滞合并轻度胎头位置异常(枕横位、枕后位)采用0.25％布比卡因作硬膜外阻滞麻醉。发现:①硬膜外阻滞可改善宫缩性质,使子宫收缩协调,宫口扩张加速,尤其适用于高度紧张和高张性子宫收缩乏力者。②硬膜外阻滞可松弛盆底肌,减轻产道对胎头的压迫,有利于克服轻度头盆不称,使阻滞的胎头下降。本组除4例因低张性子宫收缩乏力、胎头下降停滞行剖宫产术外,其余全部经阴道分娩。③与同期分娩、同等条件诊断为相对性头盆不称行剖宫产术56例产妇作对照。硬膜外阻滞组的产后出血和产后病率均显著低于对照组(P<0.025,P<0.005)。     

Translation and validation of the Transition Readiness Assessment Questionnaire (TRAQ)

Objective

To translate and validate the Brazilian Portuguese version of the Transition Readiness Assessment Questionnaire in a population of adolescents and young adults with chronic rheumatologic disorders. This questionnaire evaluates the patient's readiness for making the transition from the pediatric health service to adult care.

Prevalencia y valor pronóstico del síndrome del enfermo eutiroideo en niños críticos

Introduction

Alterations in thyroid hormones during critical illness, known as non-thyroidal illness syndrome (NTIS), were suggested to have a prognostic value. However, pediatric data is limited. The aim of this study was to assess prevalence and prognostic value of NTIS among critically ill children.

International EMS systems: The United States: past, present, and future

Emergency medical services (EMS) is an organised system designed to transport sick or injured patients to the hospital. Though EMS system configurations can be quite varied in design depending on locale, we provide an overview of EMS as it has evolved and is currently modelled in the US. We outline the history of EMS in the US, including the major events and legislation that shaped the current models that are in existence. We provide an overview of provider training, system design, system funding, and dispatch issues. The concepts of medical direction for physician surrogates, as well as EMS as it relates to specialty care are also elucidated.     

Glutamate transport in rat cerebellar granule cells is impaired by inorganic epileptogenic agents

There is evidence that extracellular glutamate levels are elevated in certain brain regions immediately prior to and during induction and propagation of seizures. There appears to be a correlation between the capacity of removing released glutamate and the genesis of epileptiform activity. Some models make use of metals, such as Co²⁺ and Ni²⁺, to induce epilepsy. We used patch-clamp recordings to measure the electrogenic glutamate transport in neuronal cells. The present results indicate that Co²⁺ (1 mM) and Ni²⁺ (5 mM) blocked glutamate transport by 17.6±3.9% (n=5, P<0.05) and by 31.8±6.2% (n=7, P<0.05), respectively. Ni²⁺ inhibited glutamate uptake in a dose-dependent manner. The IC₅₀ value obtained was 66.6 μM and the maximum inhibition was 40%. We conclude that one mechanism that may explain the seizures induced by exposure to those divalent cations is inhibition of the glutamate transporter.     

Hearing rehabilitation with osseointegrated hearing implant in bilateral congenital external auditory canal atresia

Introduction and objectivesCongenital atresia of the external auditory canal (EAC) is a congenital defect present in one in every 10,000–20,000 births. It causes conductive hearing loss, with an air-bone gap of 50–60 dB. Early amplification is essential in bilateral cases to ensure normal language development. The aim of this study is to present the osseointegrated hearing implant as a treatment for bilateral EAC atresia, reviewing the audiometric results and the rate of complications.Material and methodsRetrospective analysis of patients diagnosed with bilateral congenital EAC atresia under follow-up in the pediatric ENT clinic of the ENT and Head and Neck Surgery department of a Portuguese Tertiary Hospital, between 2003 and 2019. We reviewed the medical records and collected information on the assessment of the initial audiometric status. In the cases submitted for implantation with an osseointegrated hearing implant, we analyzed the details of follow-up, including immediate and long-term post-operative complications, as well as the audiometric results.ResultsWe present 8 pediatric patients, 6 girls and 2 boys, with a diagnosis of bilateral congenital EAC atresia. The audiometric assessment revealed moderate to severe bilateral conductive hearing loss with a mean speech recognition threshold (SRT) of 51 dB. Six patients underwent osseointegrated hearing implantation. All 6 patients showed good audiometric results, with an average SRT of 20 dB and closure of the air-bone gap.ConclusionsThe osseointegrated hearing implant was an effective treatment option in these patients, without significant morbidity or complications. Osseointegrated hearing implantation should be considered first line treatment for children with bilateral congenital EAC atresia, as it presents good functional results and a high level of patient satisfaction.     

加味四逆散长期毒性实验及安全性评价

目的通过长期毒性试验，观察加味四逆散对SD大鼠所发生的各种毒性反应，以评价加味四逆散的安全性。方法SD大鼠80只，雌雄各半，随机分为4组（空白对照组、加味四逆散高、中、低剂量组）每组各20只，三个用药组灌胃18w及停药2w后分别检测体重、血象、肝功、肾功、脏器系数及脏器组织病理。结果各给药组大鼠的血象、肝功、肾功、脏器系数分别与对照组相比差异无显著性意义（P〉0．05）。光镜下高剂量组大鼠心肌见嗜碱性变，心肌轻度充血，其余各组大鼠心脏结构清楚，肌纤维未见变性、坏死、断裂、心内外膜以及间质未见明显变化；停药2w后，各组动物脏器组织均正常，各给药组大鼠的血象、肝功、肾功、脏器系数分别与对照组相比差异无显著性意义（P〉0．05）。结论加味四逆散口服给药对正常大鼠的一般行为无明显影响，对大鼠肝脏、脾脏、肾脏、肺脏、子宫、卵巢、睾丸及肾上腺等组织无明显影响；长期高剂量口服给药对大鼠心脏有轻度的可逆性损伤；本实验表明加味四逆散停药后对大鼠无延迟毒性作用；对正常大鼠总体是基本安全的。