Rigid membranes of Malayan ovalocytes: a likely genetic barrier against malaria

A high frequency of nonhemolytic hereditary ovalocytosis in Malayan aborigines is thought to result from reduced susceptibility of affected individuals to malaria. Indeed, Kidson et al. recently showed that ovalocytes from Melanesians in Papua New Guinea are resistant to infection in culture by the malarial parasite Plasmodium falciparum. In order to determine if protection against parasitic invasion in these ovalocytes might be the result of some altered membrane material property in these unusual cells, we measured their membrane and cellular deformability characteristics using an ektacytometer . Ovalocytic red cells were found to be much less deformable in comparison to normal discoid red cells. Similar measurements on isolated membrane preparations revealed a marked reduction in ovalocytic membrane deformability. To produce equal deformation of ovalocytic and normal membranes, ovalocytes required an 8-10-fold increase in applied shear stress, indicating that their membrane was capable of deforming under sufficient stress. To test the possibility that this increased membrane rigidity might confer resistance to parasitic invasion, we performed an in vitro invasion assay using Plasmodium falciparum merozoites and Malayan ovalocytes of varying deformability from seven different donors. The level of infection of the ovalocytes ranged from 1% to 35% of that in control cells, and the extent of inhibition appeared to be closely related to the reduction in membrane deformability. Moreover, we were able to induce similar resistance to parasitic invasion in nonovalocytic normal red cells by increasing their membrane rigidity with graded exposure to a protein crosslinking agent. Our findings suggest that resistance to parasite invasion of Malayan ovalocytes is the result of a genetic mutation that causes increased membrane rigidity.     

Prognostic Significance of Somatostatin Receptor Heterogeneity in Progressive Neuroendocrine Tumor Treated with Lu-177 DOTATOC or Lu-177 DOTATATE

European Journal of Nuclear Medicine and Molecular Imaging - One of the primary prerequisites for peptide receptor radionuclide therapy (PRRT) in patients with neuroendocrine tumors (NET) is the...     

Computer-assisted surgery in orthopedic oncology: Technique,indications, and a descriptive study of 130 cases

Background and purpose —

In orthopedic oncology, computer-assisted surgery (CAS) can be considered an alternative to fluoroscopy and direct measurement for orientation, planning, and margin control. However, only small case series reporting specific applications have been published. We therefore describe possible applications of CAS and report preliminary results in 130 procedures.

Patients and methods —

We conducted a retrospective cohort study of all oncological CAS procedures in a single institution from November 2006 to March 2013. Mean follow-up time was 32 months. We categorized and analyzed 130 procedures for clinical parameters. The categories were image-based intralesional treatment, image-based resection, image-based resection and reconstruction, and imageless resection and reconstruction.

Results —

Application to intralesional treatment showed 1 inadequate curettage and 1 (other) recurrence in 63 cases. Image-based resections in 42 cases showed 40 R0 margins; 16 in 17 pelvic resections. Image-based reconstruction facilitated graft creation with a mean reconstruction accuracy of 0.9 mm in one case. Imageless CAS was helpful in resection planning and length- and joint line reconstruction for tumor prostheses.

Interpretation —

CAS is a promising new development. Preliminary results show a high number of R0 resections and low short-term recurrence rates for curettage.Oncological surgical treatment can be considered to be a trade-off between margins and function, with margins being the most important factor to consider. Accuracy is needed to achieve an efficient but oncologically safe result. To assist in this, most procedures in bone tumor surgery require intraoperative imaging with fluoroscopy and/or measurements with rulers for anatomical orientation and margin control. The best examples of this are pelvic resections. Cartiaux et al. (2008) demonstrated that 4 experienced surgeons could achieve a 10-mm resection margin, with 5-mm tolerance, on pelvic sawbones in only half of the resections. The supportive imaging and measuring modalities have, however, remained more or less unchanged for many years. In a 2-dimensional (2D) workflow such as fluoroscopy, there is still the requirement for an accurate frame of reference based on anatomical landmarks for adequate 3-dimensional (3D) margin control.In recent years, the use of computer-assisted surgery (CAS) in orthopedic surgery has become more common as an alternative for intraoperative imaging and measurements, providing the necessary precision in bone tumor surgery. The technique that is mostly used in orthopedic oncology is image-based navigation. The patient’s own anatomy (MRI and/or CT) is entered into the system and used during surgery. This provides real-time, continuous, 3D imaging feedback and may lead to more precise margin control, better tissue preservation, and new approaches to reconstruction while remaining oncologically safe. Several publications have supported CAS as being a safe navigation platform for planning and performing resections (Wong et al. 2007, So et al. 2010, Cho et al. 2012). A recent publication describes lessons in the technological approach and offers comments on CAS workflow (Wong 2010). However, to date the largest case series have involved only 20 and 31 cases (Cheong and Letson 2011, Jeys et al. 2013). The reported use has mostly been limited to complex tumor resections (e.g. pelvic), and due to the novelty of the technique, applications, approaches, and set-up times differ greatly (Saidi 2012). Here we describe possible applications of CAS in bone tumor surgery (also outside of complex resections), consider their usefulness, and report preliminary results from 130 CAS procedures performed at a single institution.     

Does a pressure increase translate into an adjacent compartment? A cadaver study

Objectives

The influence of local pressure elevation on the adjacent compartment of the lower limb is poorly described. We examined these effects in a non-fractured cadaver model.

Methods

Paired legs of unfrozen specimens were used. The pressure in the anterior and in the peroneal compartment of the contralateral limb was raised by bolus injections of saline (5cc bolus/60 seconds. Pressure changes in the adjacent compartments were measured.

Results

Pressure increase in the anterior and peroneal compartment, up to 100 mmHg did not affect the mean maximum pressure changes in the other compartments. Exceeding 100 mmHg in the anterior compartment, the peroneal pressure was 13.67 mmHg(range 8–20 mmHg), the deep posterior 7.50 mmHg(5–13 mmHg) and the superficial compartment pressure was 6.67 mmHg(4–9 mmHg). In cases of raised pressures in the peroneal compartment above 100 mmHg, the anterior, deep and superficial posterior compartments showed pressures of 12.5 mmHg(11–15 mmHg), 7.5 mmHg(4–11 mmHg), and 7.5 mmHg(4–12 mmHg).

Conclusions

Our data suggest that increased pressures in the anterior tibial or peroneal compartments do not directly influence the neighbouring compartments. It appears that in an intact compartment, the fascia seals pressure elevations in the range that is clinically relevant. Whether or not this may have clinical impact on the indications for single versus multiple compartment fasciotomy should be subject to further studies.     

Polymicrobial sepsis induces organ changes due to granulocyte adhesion in a murine two hit model of trauma.

INTRODUCTION: Polytrauma patients, who develop organ dysfunction, have often undergone multiple subsequent insults ("hits"). The sequence of organs that show a dysfunction mostly is lung, liver, kidney and heart. The aim of the present study was to investigate whether a second hit after trauma induces organ changes. Furthermore, it was of interest to identify possible pathogenic mediators such as polymorphonuclear granulocytes (PMN) and cytokines. For this purpose, a two hit model of systemic damage in mice was developed. Sepsis was induced by caecal ligation and puncture (CLP), which was preceded 48 hours by a femur fracture, the most common fracture of long bones in trauma patients. This fracture was combined with a haemorrhagic shock. METHODS: In both mouse groups studied, a standardized femur fracture was produced using a blunt guillotine device with a weight of 500 g. This was followed by a haemorrhagic shock with substitution of ringer's lactate after 1 hour. In the study group, CLP was induced by puncturing the caecum using a 21G needle. As a control, sham animals underwent a laparotomy without CLP. Both groups were sacrificed after 48 or 96 hours. Clinical parameters were investigated on a daily basis to evaluate the animals' status. Lung, liver and kidney morphology was studied by light microscopy. PMN adhesion was determined by counting the number of adherent PMN per 100 microm of endothelium. Serum levels of TNF-alpha were measured after 48 and 96 hours. RESULTS: In the group submitted to laparotomy, all animals survived. The induction of polymicrobial sepsis by CLP resulted in an 85% (34/40) mortality within 96 hours after surgery (p < 0.05). The induction of a polymicrobial sepsis resulted in a significantly steady worsening of the clinical situation compared to the sham animals (p < 0.05). Lung morphology demonstrated significant changes at the end of the experimental period after 96 h in the two hit group. The alveolar septa were thickened and in all lungs haemorrhagic foci were observed. The number of PMN adhering to the pulmonary endothelium significantly increased at 96 hours. Some of the liver specimens in the two hit group showed focal hydropic degeneration and PMN infiltration. No kidney pathology was observed. This result coincided with an increase in TNF-alpha serum levels. DISCUSSION: A new rodent model mimicking the situation in the polytraumatized patient was developed. Although the animals showed minimal organ manifestation, a high percentage died probably due to cytokinemia. Furthermore, the increased TNF-alpha levels may lead to increased adhesion of PMN in the lung venules. This adhesion developed four days after the second hit. This might be the initial step for the development of extensive lung lesions in later phases. This model represents the SIRS more than MODS. This is a model for devolopment of posttraumatic disease due to cytokinemia and less for chronic multiple organ dysfunction and failure.     

清开灵与利巴韦林治疗小儿呼吸道合胞病毒肺炎的比较：单盲、随机、平行对照试验

目的:比较清开灵与利巴韦林对呼吸道合胞病毒肺炎患儿治疗效果的差异。方法:选择2005-02/2006-04在北京儿童医院分中心治疗的小儿呼吸道合胞病毒肺炎97例,患儿法定监护人知情同意。采用单盲、随机、平行对照试验的原则,按区组随机化方法分为2组,清开灵注射液组49例,利巴韦林组48例。①清开灵注射液组:清开灵注射液静脉滴注加口服中成药。②利巴韦林组:利巴韦林注射液静脉滴注加口服复方愈创木酚磺酸钾口服液。两组疗程均为10d,比较两组患儿的疗效。结果:清开灵注射液组脱落3例,利巴韦林组脱落1例,进入结果分析清开灵注射液组46例,利巴韦林组47例。①清开灵注射液组发热患儿体温恢复正常时间比利巴韦林组短[(2.72±1.86)d,(6.29±2.41)d(P<0.01)]。②清开灵注射液组患儿咳嗽、痰壅、气促症状积分改善方面优于利巴韦林组(P<0.05～0.01)。③清开灵注射液组的呼吸道合胞病毒转阴时间明显优于利巴韦林组。④咳嗽、痰壅、病毒转阴时间、气促均进入Logistic模型,其中前两个症状的回归系数绝对值较大。结论:清开灵注射液治疗小儿呼吸道合胞病毒肺炎在退热、止咳平喘、呼吸道合胞病毒转阴时间等方面均具有明显优势,咳嗽、痰壅这两个症状更能反映清开灵注射液的疗效优于利巴韦林。     

人羊膜间充质细胞具有分化成软骨及成骨细胞的潜能

目的:人羊膜间充质细胞具有比骨髓间充质干细胞更强的扩增能力和免疫原性低等优势。建立体外适宜的诱导培养条件,观察人羊膜间充质细胞定向分化为软骨细胞和成骨细胞的能力。方法:实验于2005-09/2006-12在贵州省细胞工程重点实验室完成。①材料来源:经产妇知情同意,无菌采集健康足月分娩新生儿胎盘6份,实验经医院医学伦理委员会批准。②实验方法:采用机械法剥离羊膜组织,二步酶消化法分离收获人羊膜间充质细胞,按2.2×10~8L~(-1)密度接种,传至第1～2代用于诱导分化实验。向软骨细胞诱导分化时,人羊膜间充质细胞按3×10~8L~(-1)密度接种,诱导培养液为含体积分数0.01的胎牛血清、10 mg/L转化生长因β1、100 nmol/L地塞米松、50 mg/L抗坏血酸、1%培养基添加物。向成骨细胞诱导分化时,人羊膜间充质细胞按6×10~7L~(-1)密度接种,诱导培养液为含体积分数0.1的胎牛血清、100 nmol/L地塞米松、50 mg/L抗坏血酸、5 mmol/Lβ-甘油磷酸。③实验评估:原代细胞用流式细胞仪分析表型,免疫细胞化学染色进行波形蛋白表达鉴定。分别于体外诱导第7,14,21,28天采用免疫细胞化学法检测软骨特异性Ⅱ型胶原的表达,细胞化学法检测蛋白聚糖的表达,钙-钴法检测成骨细胞特异性碱性磷酸酶的表达,茜素红S检测钙盐沉积情况。结果:①免疫组化与表型特征:人羊膜间充质细胞高表达间充质干细胞表面标志CD29、CD44和间充质细胞标志波形蛋白。②向软骨细胞诱导分化:诱导14 d后,人羊膜间充质细胞由长梭型逐渐变为多角形,可检测到Ⅱ型胶原蛋白表达及软骨细胞特异性细胞外基质蛋白聚糖。③向成骨细胞诱导分化:诱导21 d后,可观察到人羊膜间充质细胞的胞浆内有碱性磷酸酶表达,且可见钙盐沉积。结论:人羊膜间充质细胞具有分化成软骨细胞和成骨细胞的特性,可作为骨及软骨组织工程种子细胞的新来源。