Laser energy threshold for thermal vascular injury in a port-wine stain skin model

Monte Carlo simulation of laser energy deposition in a port-wine stain (PWS) skin model and numerical solution of the thermal diffusion equation have been used to calculate threshold energies for thermal injury of PWS blood vessels for different vessel sizes and laser pulse durations. It has been assumed that an average vessel temperature rise of 65 C causes thermal injury to the blood vessel. The result is that for a certain combination of wavelength, pulse duration and incident energy density, only a limited range of blood vessel sizes can be injured optimally. Higher energy densities are required to injure smaller vessels with the same pulse duration, spot size and wavelength. This gives support to the mechanisms of selective photothermolysis suggested previously by Anderson and Parrish, although their model was based on the cooling behaviour of instantaneously heated vessels. The authors hypothesize that different laser parameter settings that match the individual PWS vessel anatomy during treatment will be used in the future, instead of many treatments with the same laser parameters. This could lead to less treatment sessions and to an improved predictability of clinical results.     

Efficacy of high dose amino acid solution on spinal cord injury induced by focal Nd : YAG laser irradiation

Summary In this experimental study, a neodymiumyttrium-aluminium-garnet (NdYAG) laser was used to induce highly reproducible focal spinal cord lesions in anaesthetized guinea pigs. The efficacy of high dose amino acid solution (HDAAS) on this injury is investigated. Experiments were performed on 36 animals divided into three groups; sham operated controls, laser irradiated surgical controls, and amino acid groups. Acute responses to injury were evaluated with somatosensory (SSEP) and motor evoked potentials (MEP) and functional recovery was assessed for 8 weeks using the inclined plane technique.In the laser irradiated surgical control group, MEP disappeared one hour after the laser injury, but SSEP revealed changes of amplitude and latency. In this group, the average value of the inclined plane at 24 hours after the laser application was 45.3±1.4 degrees. In the amino acid group, at the sixth hour of injury, MEP and SSEP changes improved with infusion of HDAAS for 4 hours. This improvement was statistically significant (for latency of SSEP U=140 p<0.05). Inclined plane value at 24 hours after the laser application was 65.5±1.2 degrees in this group.This study showed that application of NdYAG laser irradiation on the spinal cord induced spinal cord injury which presented as paraparesis, HDAAS may provide significant therapeutic protection in secondary damage following this injury and may have a potential role in the treatment of acute spinal cord injury.     

腰椎斜外侧椎间融合术后融合器沉降的原因分析

目的:观察斜外侧椎间融合(oblique lateral interbody fusion,OLIF)治疗腰椎病变术后融合器沉降现象,总结融合器沉降特点,并分析其原因,提出预防性措施。方法:回顾性分析2015年10月至2018年12月收治的144例腰椎病变资料,其中男43例,女101例;年龄20~81(60.90±10.06)岁;腰椎间盘退行性病变17例,巨大型腰椎间盘突出12例,椎间盘源性腰痛5例,腰椎管狭窄症33例,腰椎退行性滑脱26例,腰椎椎弓峡部裂伴椎体滑脱28例,腰椎内固定术后邻椎病11例,炎症转归期原发性椎间隙炎7例,腰椎退行性侧后凸5例。术前双能X线骨密度检查提示存在骨量减少或骨质疏松57例,骨密度正常87例。融合节段数:单节段124例,2节段11例,3节段8例,4节段1例。采用Stand-alone OLIF 40例,OLIF联合后路椎弓根螺钉固定104例。记录术后融合器沉降的发生情况,对可能风险因素进行单因素分析,观察融合器沉降对于临床结果的影响。结果:所有手术顺利完成,手术时间中位数99 min,术中出血量中位数106 ml;术中发生终板损伤30例,合并椎体骨折5例。所有患者获得随访,时间6~30(14.57±7.14)个月。随访过程中除原发性腰椎间隙炎病例、部分腰椎椎弓峡部裂伴椎体滑脱病例,其余出现不同程度的融合器沉降现象,其中正常沉降119例,异常沉降25例(Ⅰ级23例,Ⅱ级2例)。未出现椎弓根螺钉系统松动或断裂现象,椎间隙高度由术前的(9.48±1.84) mm恢复至术后3~5 d的(12.65±2.03) mm及末次随访时的 (10.51±1.81) mm,术后3~5 d与术前比较、末次随访与术后3~5 d比较差异均有统计学意义(P<0.05)。椎间融合率为94.4%(136/144)。腰痛和腿痛视觉模拟评分(visual analogue scale,VAS)分别由术前的(6.55±2.29)、(4.72±1.49)分降低至末次随访时的(1.40±0.82)、(0.60±0.03)分(P<0.000 1);ODI由术前的(38.50±6.98)%恢复至末次随访时的(11.30±3.27)%(P<0.05)。并发症发生率为31.3%(45/144),再手术率9.72%(14/144),其中因融合器沉降或移位而再次手术8例,占再手术的57.14%(8/14)。单因素分析结果显示:在骨量减少或骨质疏松组、Stand-alone OLIF组、2节段或以上融合组、终板损伤组中其异常沉降例数分别高于骨量正常组、OLIF联合椎弓根螺钉固定组、单节段融合组、终板无损伤组。结论:融合器沉降是OLIF术后较为常见的现象,术前骨量减少或骨质疏松、Stand-alone OLIF应用、2节段或以上融合和术中终板损伤可能是术后融合器沉降的重要因素。虽然融合器沉降程度与临床症状无明显相关,但存在融合器移位的风险,需要加强预防,以降低因融合器沉降而带来的严重并发症,包括再手术。     

基于TNFR/RIPK1通路探索紫草素对大鼠脊髓损伤的作用及机制

目的:初步探讨紫草素对大鼠急性脊髓损伤(spinal cord injury,SCI)后神经功能恢复的影响及作用机制。方法:将96只Sprague-Dawley(SD)雄性大鼠分为4组:假手术组,即A组;假手术+紫草素组,即B组;脊髓损伤+二甲基亚砜(dimethyl sulfoxide,DMSO)组,即C组;脊髓损伤+紫草素组,即D组;每组24只。C、D组采用钳夹法制作大鼠急性SCI 模型。所有大鼠硬膜下置管,A 组不给药,B组和D组造模后30 min 经导管注射紫草素100 mg·kg^-1,C组注射等量 DMSO,每日1次,至取材时间点。各组分别于造模后6、12 h和3 d 每组取8只大鼠,行 Basso-Beattie-Bresnahan(BBB)评分及造模后1、3、7、14、21 d行斜板实验,再处死动物取脊髓组织。造模后1 h 每组大鼠腹腔注射碘化丙啶(propidine iodide,PI)1 mg·kg^-1,术后24 h取材检测脊髓组织 PI 红染细胞数;24 h 时取材采用苏木素-伊红(haematoxylin eosin,HE)染色观察脊髓损伤情况,尼氏(Nissl)染色观察神经元存活数量,使用Western-blot技术检测 B细胞淋巴瘤-2(B cell lymphoma-2,Bcl-2)蛋白及凋亡相关蛋白受体相互作用蛋白激酶1(receptor-interacting protein kinase 1,RIPK1)的表达水平。结果:造模后A组和B组各时间点的 BBB 评分均正常,C、D组各时间点均低于A、B组,D组造模后12 h和3 d的 BBB 评分高于同时间点C组(P<0.05)。造模后12 h,D组PI 红染细胞较C 组明显减少,神经元崩解减轻(P<0.05)。造模后24 h,A 组和 B 组脊髓组织 HE 和 Nissl 染色正常,D 组脊髓组织损伤程度和存活神经元数量均优于 C 组(P<0.05)。Bcl-2、RIPK1蛋白在A 组、B 组表达很低; RIPK1 在C组表达明显增高,在D组表达明显下降,差异有统计学意义(P<0.05);Bcl-2蛋白在D 组表达高于C 组(P<0.05)。结论:紫草素可减轻大鼠急性SCI后的病理变化,改善行为学评分,促进脊髓神经功能恢复。其具体机制可能与抑制TNFR/RIPK1信号通路介导的坏死性凋亡有关。     

羧乙基锗倍半氧化物对大鼠心肌缺血再灌注损伤的保护作用

目的：观察羧乙基锗倍半氧化物（ＣＧＳ）对大鼠实验性心肌缺血再灌注损伤的影响。方法：采用结扎大鼠冠状动脉３０ｍｉｎ后再通６０ｍｉｎ造成心肌缺血再灌注损伤模型,测定动脉血压,心律失常发生率,心律失常严重指数（ＡＳＩ）,心肌组织中丙二醛（ＭＤＡ）含量,超氧化物歧化酶（ＳＯＤ）及ＡＴＰａｓｅ活性,血清中乳酸脱氢酶（ＬＤＨ）的水平等指标。结果：预防性静注ＣＧＳ（５０ｍｇ／ｋｇ）可显著降低再灌注心律失常发生率,心肌组织中ＭＤＡ和血清中ＬＤＨ的水平;明显改善再灌注后动脉血压的下降,心肌组织中ＳＯＤ及ＡＴＰａｓｅ活性的降低。结论：ＣＧＳ对大鼠实验性心肌缺血再灌注损伤具有保护作用     

严重脑损伤后早期肠内营养支持的合理应用

目的：传统的鼻饲营养方法因脑损伤胃动力下降早期难以安全实施。本研究对４１例严重脑损伤病人实施改良后的早期鼻饲喂养计划,观察其应用的合理性和临床效果。方法：实验组采用了早期鼻饲要素膳,对照组按常规方法实施鼻饲营养支持;实验组开始时间为伤后４８ｈ,对照组为伤后６－８天。     

Mortality among young immigrants to California: injury compared to disease deaths

According to a variety of indicators, immigrants are in better health than the U.S.-born population. Little research, however, has investigated foreign- and U.S.-born differentials in mortality. We investigated adolescent and young adult immigrants' risk of death due to disease and injury, the leading cause of death of young persons in the United States. The death certificates of 15- to 34-year-old California residents who died from 1989 through 1993 comprised the study population. Disease and injury deaths were identified using ICD-9 codes on the California Master Mortality data files. Frequencies and gender-standardized rates and risk ratios were calculated by nativity (U.S., non-U.S.) and by ethnicity and nativity. Immigrants are represented appropriately in unintentional injury deaths but underrepresented in suicides and overrepresented in homicides among 15- to 34-year-old California residents. Hispanics appear to account for the foreign- and U.S.-born differences in suicide and homicide. By contrast, immigrants constitute a lower proportion of disease deaths than expected. Empirical data about health risks to immigrants are needed to develop informed policy. These data indicate that young immigrants, at least in terms of mortality, do not constitute a burden in that they are at lower or similar risk of death than U.S.-born youth. Homicide is the sole exception to this pattern.     

血脑利钠肽和ADH变化在急性颅脑外伤中的意义

目的 探讨血脑利钠肽和ＡＤＨ变化在急性颅脑外伤中的意义。方法 对１９９６年１月￣１９９７年８月收治的７２例急性颅脑外伤（ＡＣＩ）患者血中脑利钠肽（ＢＮＰ）、抗利尿激素（ＡＤＨ）含量进行监测,并对ＧＣＳ〈８分病例行促甲状腺素释放激素（ＴＲＨ）刺激试验。结果 ＡＣＩ患者血ＢＮＰ浓度明显降低,血ＡＤＨ浓度明显增高,其改变程度与脑外伤程度,脑实质细胞损害程度及脑伤预后密切相关,结论 ＡＣＩ导致下丘脑垂体功     

P选择素和ICAM—1在肾缺血再灌注损伤中的作用

目的 探讨Ｐ选择素和细胞间粘附分子－１（ＩＣＡＭ－１）在肾缺血再灌注损伤中的作用。方法 建立缺血再灌注损伤大鼠模型,观察缺血再灌注后肾组织Ｐ选择素和ＩＣＡＭ－１的表达,并用Ｐ选择单克隆抗体进行了治疗。结果 发现缺血再灌注后肾小管人泡变性玫片状坏死,血尿素氮（ＢＵＮ）和肌酐（ＳＣｒ）水平升高;但再灌注前５ｍｉｎ经Ｐ选择互单抗处理的动物肾组织与正常相近,肾小管上皮细胞未见变性及坏死,血ＢＵＮ和ＳＣｒ水     

博莱霉素致肺损伤作用研究

为探讨使用博莱霉素的患者产生肺炎样症状和肺纤维化样症状的机理,给动物从气管内注入博莱霉素A_5,观察其对肺脏的作用。发现该药到达肺组织后,可引起明显的肺损伤。早期先引起肺泡炎,后期可导致肺纤维化。实验从病理学上揭示了博莱霉素引起肺炎样和肺纤维化样症状的原因。提示在给患者使用博莱霉素时,一旦其出现了肺炎样症状,就应及时停药并进行胸部X线检查,及时给予适当处理,以防止肺纤纤维化的发生。