髌腱外偏角的测量及在复发性髌骨脱位诊断中的应用

目的:比较髌腱外偏角和胫骨结节-滑车沟距离(tibia tubercle-trochlea groove,TT-TG)的CT测量结果,以及在复发性髌骨脱位中的诊断能力和病理阈值。方法:自2015年1月至2020年3月对46例复发性髌骨脱位患者和112例非髌骨脱位患者的病例资料进行回顾性分析。46例复发性髌骨脱位患者根据TT-TG值分为2组:TT-TG ≥ 20 mm髌骨脱位(A组)11例,男7例,女4例;年龄16~27(21.00±3.98)岁;TT-TG<20 mm髌骨脱位(B组)35例,男14例,女21例;年龄16~37(22.83±6.09)岁;非髌骨脱位(C组)112例,男63例,女49例;年龄16~36(22.87±5.69)岁。比较3组患者的髌腱外偏角和TT-TG值的测量数据,并采用Spearman分析其相关性。采用同类相关系数(intraclass correlation coefficient,ICC)确定组内的可重复性。利用受试者工作特征(receiver operating characteristic,ROC)曲线下面积评价参数的诊断能力,并计算出髌腱外偏角截骨参数,以及髌腱外偏角和TT-TG值在诊断复发性髌骨脱位的诊断参数。结果:A、B、C组的髌腱外偏角分别为(22.04±3.19)°、(17.20±4.43)°、(10.22±3.45)°,TT-TG值分别为(21.15±0.71)、(15.97±2.69)、(11.12±3.77) mm,3组比较差异有统计学意义(P<0.01),且A组与B组比较差异有统计学意义(P<0.01)。髌腱外偏角与TT-TG值对比,存在强正相关(r=0.735,P<0.000 1)。髌腱外偏角在A、B组中的组内ICC值(0.980、0.982)比TT-TG值(0.594、0.775)测量的可重复性更好,C组中髌腱外偏角(0.956)和TT-TG值(0.906)可重复性均很好。在复发性髌骨脱位诊断中,髌腱外偏角的ROC曲线下面积(0.916)大于TT-TG值(0.886),其诊断参数分别为13.84°和14.69 mm;在胫骨截骨术中,髌腱外偏角的ROC曲线下面积为0.821,截骨参数为20.15°。结论:CT成像可以可靠地测量髌腱外偏角。髌腱外偏角与TT-TG值存在强正相关,可通过其测量明确复发性髌脱位病理状态,并且髌腱外偏角在复发性髌骨脱位的诊断能力优于TT-TG值。髌腱外偏角同样可用于指导复发性髌骨脱位的胫骨截骨手术方案的制定。     

胫骨结节相对旋转度：一种新的评估髌股关节不稳的参数

目的 探讨胫骨结节相对旋转度（tibial tubercle-trochlear groove rotation angle,TTTGR）与髌股关节不稳的相关性,评估这一参数对于髌股关节不稳的诊断效力。方法 收集2020年1月至2020年12月于我科就诊的髌骨复发性脱位病人50例纳入脱位组,30例正常志愿者纳入对照组。四名观察者分别对两组病人的双膝关节CT影像进行分析,测量TTTGR、胫骨结节-滑车（tibial tubercle-trochlear groove,TT-TG）距离、滑车侧倾角（lateral trochlear inclination,LTI）、髌骨外倾角度（lateral patella tilt angle,LPTA）。评估各参数在观察者间的一致性,分析两组间上述参数的差异,TTTGR与其他参数的相关性,采用受试者工作特征（receiver operating characteristic,ROC）曲线分析各参数对于预测髌股关节不稳的灵敏度、特异度、阳性及阴性预测值。结果 脱位组的TTTGR、TT-TG、LPTA均显著高于对照组,LTI显著低于对照组,组间比较,差异有统计学意义（P＜0.05）。观察者间的一致性检验结果：TT-TG（ICC=0.975）、TTTGR（ICC=0.937）和LPTA（ICC=0.794）的组间一致性均为优秀,LTI（ICC=0.708）的组间一致性良好。TTTGR与TT-TG、LPTA呈正相关（r=0.544,r=0.476）,与LTI呈负相关（r=-0.430）。TT-TG对于髌股关节不稳的诊断准确性最高,约登指数：0.851,TTTGR诊断准确性次之（约登指数：0.733）,LTI则无诊断意义。其中,TTTGR的最佳截断值为34.6°,表现出敏感度为80.00%,特异度为93.30%;阳性预测值为92.27%,阴性预测值为82.34%。结论 TTTGR是可重复性高、可靠的髌股关节不稳评估指标,与TT-TG、LPTA等参数具有相关性,对于髌股关节不稳具有较高的诊断效力。     

比较前交叉韧带撕裂与髌骨外侧脱位患者髌股关节解剖学参数异常检出率

目的 对比前交叉韧带（ACL）撕裂与髌骨外侧脱位（LPD）患者之间，股骨滑车发育不良、髌骨高位、胫骨结节-股骨滑车沟（TT-TG）间距过宽检出率的差异。方法 回顾性分析79例ACL撕裂患者（ACL撕裂组）、46例LPD患者（LPD组）及100例膝关节未见明显异常者（对照组）的膝关节MRI，对比3组间股骨滑车发育不良、髌骨高位（Insall-Salvati指数>1.2）及TT-TG间距过宽（TT-TG间距>15 mm为过宽）检出率的差异。结果 ACL撕裂组中，股骨滑车发育不良18例（18/79，22.78%），髌骨高位12例（12/79，15.19%），TT-TG间距过宽10例（10/79，12.66%）；LPD组中，股骨滑车发育不良26例（26/46，56.52%），髌骨高位21例（21/46，45.65%），TT-TG间距过宽13例（13/46，28.26%）；对照组股骨滑车发育不良9例（9/100，9.00%），髌骨高位6例（6/100，6.00%），TT-TG间距过宽5例（5/100，5.00%）。3组间股骨滑车发育不良、髌骨高位和TT-TG间距过宽检出率差异均有统计学意义（P均<0.01）；LPD组股骨滑车发育不良、髌骨高位检出率均高于对照组及ACL撕裂组（P均<0.05），TT-TG间距过宽检出率高于对照组（P<0.05）；ACL撕裂组TT-TG间距过宽检出率与LPD组及对照组差异均无统计学意义（P均>0.05）。结论 股骨滑车发育不良、髌骨高位及TT-TG间距过宽在ACL撕裂与LPD患者中的检出率均较高；前二者在LPD中尤为显著。     

韧带张力测量在髌骨外脱位内侧髌股韧带重建术中的应用评价

目的 评价重建韧带张力的测量在髌骨外脱位内侧髌股韧带（medial patellaremoral ligament,MPFL）重建术中的应用效果。方法 前瞻性纳入我科2014年1月至2018年12月收治的髌骨外脱位病人共75例,并随机分为两组。观察组36例,利用拉力秤张力测量的方法,选取自身的胫骨结节内侧半腱肌腱,镜下辅助双股MPFL重建术进行治疗;对照组39例,术中未使用拉力秤,以手法复位髌骨的方式重建MPFL。术后采用膝关节损伤和骨关节炎评分（knee injury and osteoarthritis outcome score,KOOS）、Kujala评分、髌骨适合角、髌骨倾斜角来评价临床效果。结果 随访过程中3例病人失访（观察组1例,对照组2例）,72例随访14~54个月（平均42个月）。两组病人治疗后的KOOS评分、Kujala评分、髌骨适合角、髌骨倾斜角均较术前得到改善,与术前数值比较,差异有统计学意义（P＜0.05）。但两组手术前后的KOOS评分、Kujala评分、髌骨适合角、髌骨倾斜角的差值比较,差异无统计学意义（P＞0.05）。对照组1例病人术后出现髌骨高压的症状。结论 术中采用拉力秤辅助固定韧带是简单有效的预防术后髌股关节高压症的方法。     

MAKO机器人辅助与传统手工全膝关节置换术后下肢力线的对比研究

目的 比较MAKO机器人辅助与传统手工全膝关节置换术（TKA）术后下肢力线的准确性。方法 对2021年5月至2021年12月在解放军总医院第四医学中心骨科医学部关节外科行TKA治疗的74例（78膝）病人的临床资料进行回顾性分析,其中采用MAKO机器人辅助下TKA的37例（41膝）纳入机器人组,同期使用相同膝关节假体行传统手工手术的37例（37膝）纳入传统手工组。分别记录两组病人术中计划与术后实际测量的胫骨近端内侧角（MPTA）、股骨远端外侧角（LDFA）和下肢力线髋-膝-踝（hip-knee-ankle,HKA）角,并进行组内及组间分析比较。结果 两组病人均顺利完成手术,术后无手术相关并发症。机器人组的手术时间长于传统手工组［（110.67±80.56） min vs. （80.56±4.64） min］,差异有统计学意义（t=12.726,P＜0.001）。机器人组术后测量的MPTA、LDFA与术中末次计划的比较,差异均有统计学意义（P＜0.05）;但其计划和实际的HKA比较,差异无统计学意义（P＞0.05）。传统手工组术后测量的MPTA、HKA与术中末次计划的比较,差异均有统计学意义（P＜0.05）;但其计划和实际的LDFA比较,差异无统计学意义（P＞0.05）。通过计算两组病人计划与实际测量的差值,并进行比较,组间差异均有统计学意义（P＜0.05）。结论 MAKO机器人辅助下行TKA术后下肢力线及假体位置平均误差在1°以内,机器人辅助技术有助于精准安放假体,并实现计划力线。     

肩关节镜下锚钉固定位置与跨度对治疗复发性肩关节前脱位预后的影响

目的 评估肩关节镜下锚钉内固定术治疗复发性肩关节前脱位的临床疗效,并探讨锚钉固定位置、跨度对临床疗效的影响。方法 2013年1月至2016年6月,前瞻性纳入47例复发性肩关节前脱位病人,关节镜下使用3枚Lupine锚钉固定撕裂的盂唇。术后第2日常规复查肩关节三维CT,以表盘上的时间刻度描述锚钉位点及跨度。采用数字分级法（numerical rating scale, NRS）评估病人的疼痛程度;使用美国肩肘外科医师学会（American Shoulder and Elbow Surgeons, ASES）评分及Constant-Murley评分评估手术前后关节功能。使用丹麦健康与医疗管理局（Danish Health and Medicine Authority）满意度评分表评估病人满意度。分析锚钉固定位置、跨度等因素与Constant-Murley评分的关系。结果 47例病人术后未出现明显并发症,术后的NRS评分、ASES评分、Constant-Murley评分均较术前显著改善,差异均有统计学意义（P均＜0.05）。病人满意度评分为（8.2±1.3）分。锚钉跨度越大,Constant-Murley评分越低（F=21.714,P＜0.001）;锚定位置越高（越接近12点钟位置）,Constant-Murley评分越低（F=13.752,P=0.006）。结论 锚钉固定前下盂唇可有效改善病人肩关节功能,有利于肩关节稳定性重建,且锚钉固定的位置及跨度与肩关节术后稳定性相关。     

自制多功能组合式复位固定钳在股骨、胫骨骨干骨折的初步应用

目的 总结自制多功能组合式复位固定钳治疗股骨、胫骨骨干骨折的临床效果。方法 回顾性分析2019年1月至2020年5月我院收治的86例股骨干骨折、胫骨干骨折病人的临床资料,根据治疗方式不同分为观察组和对照组,每组各43例。观察组采用多功能组合式复位固定钳治疗,对照组采用传统持骨钳把持。比较两组病人切口长度、术中出血量、手术时间、骨折愈合时间、并发症发生等情况。结果 对照组切口大小、术中出血量、手术时间、愈合时间均高于观察组,差异均有统计学意义（P均＜0.05）;观察组优良率为97.67%,高于对照组的83.72%,差异无统计学意义（χ²=3.445,P=0.063）;对照组（16.28%）并发症发生率高于观察组（2.33%）,差异无统计学意义（χ²=3.445,P=0.063）。结论 自制多功能组合式复位固定钳在实际操作过程中使用灵活,有利于减少创伤,方便了手术操作,缩短了手术时间,有其临床应用价值。     

3D打印技术在复杂胫骨平台骨折手术中的应用研究

目的 探讨应用3D打印技术辅助手术治疗复杂胫骨平台骨折的临床效果。方法 选取2014年1月至2017年3月我院收治的复杂胫骨平台骨折病人29例,随机分为观察组（15例）及对照组（14例）进行队列分析比较。观察组胫骨平台经Mimics软件处理,3D打印成1∶1骨折模型,将骨折及健侧模型进行镜像对比,设定手术方案;对照组常规参照术前X线片及CT制定修复方案。术后观察并对两组的手术时间、出血量、术后关节塌陷纠正情况、术后12个月膝关节Rasmussen功能评分进行比较。结果 本研究29例病人的随防时间为（12.55±2.46）个月。观察组的手术时间、出血量明显小于对照组,术后关节塌陷纠正情况优于对照组,差异均有统计学意义（t=2.297,P=0.029;t=2.674,P=0.013;t=2.658,P=0.020）;术后12个月两组膝关节Rasmussen评分差异无统计学意义（P＞0.05）;观察组膝关节功能恢复优良率（93.33%）高于对照组（78.57%）。结论 针对复杂胫骨平台骨折,应用3D打印技术制作骨折模型,通过模拟手术操作可以有效缩短手术时间,减少术中出血,纠正关节面塌陷程度。     

膝骨关节炎单髁置换术后下肢冠状位力线对早期临床效果的影响

目的 探讨单髁置换术（unicompartmental knee arthroplasty,UKA）后不同的下肢冠状位力线对早期临床效果的影响。方法 2018年8月至2019年6月,对93例（102膝）UKA术后病人进行回顾性分析,根据术后下肢力线将102膝分为三组,轻度内翻组（0°~3°）36膝、中等内翻组（3°~6°）37膝和重度内翻组（6°以上）29膝。比较三组术前及末次随访时的西安大略和麦克马斯特大学（the Western Ontario and McMaster Universities,WOMAC）骨关节炎指数及膝关节功能活动度,评估病人术后满意度。结果 随访24~34个月,平均27.1个月。末次随访时各组WOMAC评分以及轻度内翻组、中等内翻组的活动度均显著优于术前,差异有统计学意义（P＜0.05）。轻度内翻组、中等内翻组末次随访的活动度值均显著优于重度内翻组,差异有统计学意义（P＜0.05）,但轻度内翻组和中度内翻组比较,差异无统计学意义（P＞0.05）。中度内翻组中有更多的病人（70%）认为非常满意（P=0.028）。结论 UKA术中将力线调整至内翻0°~6°均可获得不错的膝关节功能评分及活动度,但UKA术后力线在3°~6°范围内的病人较0°~3°组可有更好的早期满意度。     

机器人辅助人工全膝关节置换与传统手术临床效果比较的Meta分析

目的：通过Meta分析比较机器人辅助全膝关节置换术和传统全膝关节置换术效果的差异,以明确机器人辅助全膝关节置换术是否可提供更好的假体下肢力线及临床预后。方法：计算机检索建库至2018年11月Embase、Pubmed、Web of Science数据库和中国期刊全文数据库（CNKI）、万方数据库、维普中文科技期刊数据库（VIP）,查找比较机器人辅助和传统全膝关节置换术效果差异的临床对照研究。根据纳入与排除标准进行文献筛选、质量评价及数据提取后,应用Revman 5.3软件对文献数据进行Meta分析。结果：共纳入6篇临床对照研究,机器人辅助全膝关节置换术组253例,传统全膝关节置换术组231例。Meta分析结果：机器人辅助TKA组在下肢冠状位力线角度[WMD=-1.00,95%CI（-1.66,-0.35）,P=0.003],下肢冠状位力线内翻或外翻>3°发生率[RR=0.04,95%CI（0.01,0.13）,P=0.000 01]方面优于传统全膝关节置换术组;但两组膝关节活动范围[WMD=0.06,95%CI（-5.43,5.55）,P=0.98],正位片胫骨角[WMD=-0.19,95%CI（-0.81,0.43）,P=0.55]与侧位片胫骨角[WMD=-1.37,95%CI（-3.73,0.99）,P=0.25],正位片股骨角[WMD=0.30,95%CI（-1.37,1.96）,P=0.72]与侧位片股骨角[WMD=-0.93,95%CI（-1.98,0.12）,P=0.08],并发症发生率[RR=0.84,95%CI（0.45,1.58）,P=0.60]比较,差异无统计学意义。机器人辅助TKA组手术时间长于传统TKA组[WMD=14.28,95%CI（0.79,27.77）,P=0.04]。结论：在全膝关节置换术中使用机器人辅助系统可明显提高假体固定精度,更好地重建下肢力线,并有减轻患者术后疼痛、促进膝关节功能恢复的潜在优势。受纳入文献数量与质量的限制,未来仍需长期随访的高质量随机对照研究对本文结论加以佐证。     

Matriderm versus Integra: a comparative experimental study

Aim

To compare engraftment rates and vascularisation in a rat model using either Integra Artificial Skin^® or Matriderm^®.

Methods

Matriderm^® and the dermal part of Integra^® were compared in a two-step procedure including matrix implantation and subsequent epidermal grafting. Neonatal rat epidermis was used as coverage to test for rapid and complete take.

Results

Efficiency and quality of vascularisation expressed by take rate of epidermis, and thickness of resulting neodermis, were identical for both matrices.

Conclusion

This first comparison of Matriderm^® with Integra^® in a rat model revealed no major differences in engraftment rates or vascularisation.     

Scintiscanning demonstration of thymoma: Comparative study on scintiscans using201Tl,67Ga and75Se

Thymus scintigraphy was performed using²⁰¹Tl-chloride,⁶⁷-Ga-citrate and⁷⁵Se-selenomethionine on 30 thymoma patients with or without myasthenia gravis. Mass negativity was observed in 6 out of 17 (35.3 per cent) and 3 out of 13 cases (23.1 per cent), respectively. A rate of 70 per cent (21 cases out of 30) of mass positivity was observed by thymus scan using²⁰¹Tl. With regard to the relation between thymus scan and cell type,²⁰¹Tl-scan exhibited a high rate of mass positivity, regardless of the cell type while the⁷⁵Sescan showed a trend toward mass positivity in epithelial cell predominant cases. With²⁰¹Tl, mass positivity was observed when the CPM/g ratio for tumors and blood exceeded 3.0. This trend can serve as an index for the suitability of supplementary chemo- and radiotherapies, as well as for prognosis in cases of relapse, and in those for whom excision was not complete.     

Mechanisms of PKC-Dependent Na+ K+ ATPase Phosphorylation in the Rat Kidney with Chronic Renal Failure

The present work was designed to study Na⁺ K⁺ ATPase α1-subunit phosphorylation in rats with chronic renal failure (CRF) in comparison with normal rats. Na⁺ K⁺ ATPase α1-subunit phosphorylation degree was measured by binding the McK-1 antibody to dephosphorylated Ser-23 in microdissected medullary thick ascending limb of Henle (mTAL) segments. In addition, the total Na⁺ K⁺ ATPase α1-subunit expression and activity were also measured in the outer renal medulla homogenates and membranes.

CRF rats showed a higher Na⁺ K⁺ ATPase activity, as compared with control rats (18.95 ± 2.4 vs. 11.21 ± 1.5 μmol Pi/mg prot/h, p < 0.05), accompanied by a higher total Na⁺ K⁺ ATPase expression (0.54 ± 0.04 vs. 0.27 ± 0.02 normalized arbitrary units (NU), p < 0.05). When McK-1 antibody was used, a higher immunosignal in mTAL of CRF rats was observed, as compared with controls (6.3 ± 0.35 vs.4.1 ± 0.33 NU, p < 0.05). The ratio Na⁺ K⁺ ATPase α1-subunit phosphorylation / total Na⁺ K⁺ ATPase α1-subunit expression per μg protein showed a non-significant difference between CRF and control rats in microdissected mTAL segments (2.11 ± 0.12 vs.2.26 ± 0.18 NU, p = NS). The PKC inhibitor RO-318220 10^?6M increased immunosignal (lower phosphorylation degree) in mTAL of CRF rats to 128.43 ± 7.08% (p < 0.05) but did not alter McK1 binding in control rats. Both phorbol 12-myristate 13-acetate (PMA) 10^?6M and dopamine 10^?6M decreased immunosignal in CRF rats, corresponding to a higher Na⁺ K⁺ ATPase α1-subunit phosphorylation degree at Ser-23 (55.26 ± 11.17% and 53.27 ± 7.12% compared with basal, p < 0.05). In mTAL of CRF rats, the calcineurin inhibitor FK-506 10^?6M did not modify phosphorylation degree at Ser-23 of Na⁺ K⁺ ATPase α1-subunit (100.21 ± 3.00% compared with basal CRF). In control rats, FK 506 10^?6M decreased the immunosignal, which corresponds to a higher Na⁺ K⁺ ATPase α1-subunit phosphorylation degree at Ser-23. The data suggest that the regulation of basal Na⁺ K⁺ ATPase α1-subunit phosphorylation degree at Ser-23 in mTAL segments of CRF rats was primarily dependent on PKC activation rather than calcineurin dependent mechanisms.     

Cardioprotective effects of KB-R7943, a novel inhibitor of Na+/Ca2+ exchanger, on stunned myocardium in anesthetized dogs

Purpose The present study was carried out to determine the cardioprotective effects of KB-R7943 (KBR), a selective inhibitor of the reverse mode of Na⁺/Ca²⁺ exchanger (NCX), on stunned myocardium in anesthetized dogs.Methods The dogs were allocated to one of three groups (n = 7 for each group), and received drug vehicle (group C), low-dose KBR (5mg·kg^–1 i.v.) (group L) or high-dose KBR (10mg·kg^–1 i.v.) (group H) at 15min before left anterior descending coronary artery (LAD) occlusion. Stunned myocardium was produced by 15-min occlusion of LAD and 90-min reperfusion in all dogs. Regional myocardial contractility was evaluated with segment shortening (%SS).Results Recovery of %SS at 90min after reperfusion was significantly improved in group H (70.8% ± 3.9% of baseline), whereas the recovery was poor in groups C and L (34.3% ± 2.8% and 36.4% ± 5.4% of baseline, respectively). Regional myocardial blood flow showed no significant difference among groups. KBR had no effect on coronary or systemic hemodynamics.Conclusion The results show that preischemic administration of high-dose KBR markedly improves myocardial contractile dysfunction after ischemia-reperfusion in anesthetized dogs, indicating that KBR protects myocardium against the ischemia-reperfusion injury in vivo.     

Inhibition of bone cell metabolism increases strontium-85 uptake

Summary Experiments have been performed on the canine tibia to investigate whether perturbation of the energy metabolism of bone cells can influence the short-term exchange of bone mineral. Simultaneous injection of three radioactive tracers,¹²⁵I-albumin,⁸⁵Sr, and⁸⁶Rb, into the tibial nutrient artery was followed immediately by measurement of the concentration of these tracers in the venous outflow from the bone for a period of 5 minutes. This procedure was performed before and after the injection of potassium cyanide into the bone. From the measured concentrations, extraction ratios for⁸⁵Sr and⁸⁶Rb with respect to¹²⁵I-albumin were calculated. It was found that net extraction after 5 minutes of⁸⁵Sr was significantly increased. This result indicates that efflux of ions from exchangeable mineral is dependent to a significant extent on the metabolic activity of bone cells.     

Differences in Release Mechanisms and Distributions for Sialyl Lea and Sialyl Lex Antigens in Colorectal Cancer

Background: To investigate colorectal cancer-related carbohydrate antigen release and distribution, we evaluated serum levels of sialyl Lea (CA19–9) and sialyl Lex antigen (SLX) in blood samples obtained from both a peripheral vein and a tumors draining vein.Methods: Blood samples were obtained during surgery from 126 patients. Based on these samples, patients were placed into a high-antigen group, with a concentration above a selected cutoff value, or into a low-antigen group, with a tumor marker concentration below that same value. The blood samples obtained from peripheral veins were designated by the p prefix, and samples from drainage veins were designated by the d.Results: Serum d-SLX levels were significantly higher than p-SLX levels (P, .0001), although there was no difference between those of d-CA19–9 and p-CA19–9. Only 1 (3.6%) of 28 patients in the high d-CA19–9 group had a low p-CA19–9. In contrast, 6 (33.3%) of 18 patients in the high d-SLX group had low p-SLX levels (P 5 .0103). Correlations between pathological variables and either p-CA19–9 levels or d-CA19–9 levels were similar. However, both distant metastasis and venous invasion did prove to be independent variables related to d-SLX levels, as shown by logistic regression analysis.Conclusions: SLX may drain predominantly via the draining veins of colorectal tumors into portal circulation, whereas CA19–9 may drain via another route.     

The effects of the pretreatment of intravenous high dose methylprednisolone on Na+-K+/Mg+2 ATPase and lipid peroxidation and early ultrastructural findings following middle cerebral artery occlusion in the rat

Summary The sodium-potassium activated and magnesium dependent adenosine-5-triphosphatase (Na⁺-K⁺/Mg⁺² ATPase EC.3.6.1.3.) activity and lipid peroxidation and early ultrastructural findings were determined in rat brain at the acute stage of ischaemia produced by permanent unilateral occlusion of the middle cerebral artery (MCA). The effects of the pretreatment with intravenous high-dose methylprednisolone (MP) on these biochemical indices and ultrastructural findings were also evaluated in the same model. The rats were divided into four groups. In group I, 10 rats were used to determine Na⁺-K⁺/Mg⁺² ATPase activity and the extent of lipid peroxidation by measuring the malondialdehyde (MDA) content and normal ultrastructural findings. In group II on 20 rats, only subtemporal craniectomy was done in order to determine the effects of the surgical procedure on these indices and findings. This group was treated intravenously with saline solution before occlusion. In group III with MCA occlusion, saline solution was administered intravenously to 20 rats in the same amount of methylprednisolone used in group IV, ten minutes before the occlusion. In Group IV, a single high-dose (30 mg/kg) of methylprednisolone was administered intravenously, ten minutes before occlusion in 20 rats. After occlusion of the middle cerebral artery, Na⁺-K⁺/Mg⁺² ATPase activity was decreased promptly in the first ten minutes in the ischaemic hemisphere and remained at a lower level than the contralateral hemispheres in the same group and the normal levels in group I, during 120 minutes of ischaemia. A single dose methylprednisolone pretreatment prohibited the inactivation of Na⁺-K⁺/Mg⁺² ATPase. On the other hand, there was significant difference in malondialdehyde content between group I and group III. Malondialdehyde levels were significantly increased following ischaemia and a non-significant increase was observed in the contralateral hemisphere. Methylprednisolone treatment significantly decreased malondialdehyde content on the side of the ischaemic hemisphere. We conclude that there is a positive relationship between membrane-bound enzyme Na⁺-K⁺/Mg⁺² ATPase activity, malondialdehyde content and early ultrastructural changes in the treated group with MP.These data suggest that the pretreatment injection of high doses (30 mg/kg) methylprednisolone contribute to the protection of the brain from ischaemia with stabilization of the cell membrane by effecting the lipid peroxidation and the activation of Na⁺-K⁺/Mg⁺² ATPase.     

Resolving Erythrocytosis and Hypertension after Open Surgical Extirpation of Giant Renal Cyst Measuring 30 cm: Case Report

We previously described a method to measure GFR in conscious spontaneously voiding rats. This method circumvents the need for anesthesia and for bladder instrumentation. It's main principle is the correction of renal ¹²⁵I-iothalamate clearance for incomplete urine collection by the ratio of plasma and renal clearance of co-infused ¹³¹I Hippuran. A disadvantage of this technique is the requirement of an intra-arterial catheter for infusion of the renal function tracers. We therefore tested whether intraperitoneal infusion of ¹²⁵I-Iothalamate and ¹³¹I-Hippuran can be used for such a GFR measurement in conscious spontaneously voiding rats.

We found that during intraperitoneal administration, stable plasma levels of ¹³¹I-Hippuran could be obtained. However, urinary recovery of ¹³¹I-Hippuran was incomplete (66 ± 32%), leading to a significant overestimation of GFR by 140 ± 113% in comparison with the GFR measured by the intra-arterial technique. Thus intraperitoneal infusion of renal function tracers cannot replace intra-arterial infusion.     

Regulation of cell surface polarity in renal epithelia

In the kidney, polarized epithelial cells play critical roles in ion, fluid and solute reabsorption from the ultrafiltrate to the blood supply. Detailed analysis of protein distributions has revealed that ion channels, transporters and pumps are restricted to distinct domains of the plasma membrane that face either the ultrafiltrate (apical membrane) or the blood supply (basal-lateral membrane). The importance of the development and maintenance of the polarized distributions of these proteins in renal epithelia for normal cell function is demonstrated by the fact that several disease states are characterized by abnormal distributions of proteins; for example in polycystic kidney disease, Na⁺/K⁺-ATPase has been detected in the apical and lateral membranes, compared with normal cells where Na⁺/K⁺-ATPase is localized in the basal-lateral membrane domain. Recent studies indicate that the development of restricted distributions of proteins at the cell surface of Madin Darby canine kidney epithelial cells is determined by direct sorting of proteins in thetrans Golgi network into vesicles that are delivered vectorially to either the apical or basal-lateral membrane. Upon arrival at the plasma membrane, some proteins, such as Na⁺/K⁺-ATPase, may be selectively retained by binding to the membrane cytoskeleton.