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Summary: Preoperative computed tomographic angiography is increasingly performed before perforator flap-based reconstruction. However, radiologic two-dimensional thin slices do not allow for intuitive interpretation and translation to intraoperative findings. Three-dimensional volume rendering has been used to alleviate the need for mental two-dimensional to three-dimensional abstraction. Even though volume rendering allows for a much easier understanding of anatomy, it currently has limited utility, as the skin obstructs the view of critical structures. Using free, open-source software, the authors introduce a new skin-masking technique that allows surgeons to easily create a segmentation mask of the skin that can later be used to toggle the skin on and off. In addition, the mask can be used in other rendering applications. The authors use Cinematic Anatomy for photorealistic volume rendering and interactive exploration of computed tomographic angiography with and without skin. The authors present results from using this technique to investigate perforator anatomy in deep inferior epigastric perforator flaps and demonstrate that the skin-masking workflow is performed in less than 5 minutes. In Cinematic Anatomy, the view onto the abdominal wall and especially onto perforators becomes significantly sharper and more detailed when no longer obstructed by the skin. The authors perform a virtual, partial muscle dissection to show the intramuscular and submuscular course of the perforators. The skin-masking workflow allows surgeons to improve arterial and perforator detail in volume renderings easily and quickly by removing skin and could alternatively be performed solely using open-source and free software. The workflow can be easily expanded to other perforator flaps without the need for modification., (Copyright © 2024 by the American Society of Plastic Surgeons.)

Competing Interests: The authors declare no conflicts of interest.

Summary: Genetic medicine has emerged as an innovative class of therapeutics, allowing the development of new and powerful approaches to address a myriad of diseases that were previously untreatable. At the same time, our improved understanding of the mechanisms underlying aging has created novel opportunities to intervene therapeutically in the aging process itself through the targeting of key pathways driving this process. As individuals age, the onset of a multitude of age-related diseases can significantly impact lifespan. The ultimate goal of their treatment is the maximization of healthy, disease-free years, or healthspan. Here, we discuss a number of promising genetic medicine approaches to target both general and specific mechanisms of age-related disease, and their potential impact on healthspan extension. Essential to this topic is the challenge of nucleic acid delivery, and we discuss the technologies that have been developed to address this challenge in highly promising preclinical and clinical development efforts. In particular, we describe a next-generation delivery technology for healthspan applications called proteo-lipid vehicles., (Copyright © 2022 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the American Society of Plastic Surgeons. All rights reserved.)

Rationale: While thrombin is the key protease in thrombus formation, other coagulation proteases, such as fXa (factor Xa) or aPC (activated protein C), independently modulate intracellular signaling via partially distinct receptors., Objectives: To study the differential effects of fXa or fIIa (factor IIa) inhibition on gene expression and inflammation in myocardial ischemia-reperfusion injury., Methods and Results: Mice were treated with a direct fIIa inhibitor (fIIai) or direct fXa inhibitor (fXai) at doses that induced comparable anticoagulant effects ex vivo and in vivo (tail-bleeding assay and FeCl 3 -induced thrombosis). Myocardial ischemia-reperfusion injury was induced via left anterior descending ligation. We determined infarct size and in vivo aPC generation, analyzed gene expression by RNA sequencing, and performed immunoblotting and ELISA. The signaling-only 3K3A-aPC variant and inhibitory antibodies that blocked all or only the anticoagulant function of aPC were used to determine the role of aPC. Doses of fIIai and fXai that induced comparable anticoagulant effects resulted in a comparable reduction in infarct size. However, unbiased gene expression analyses revealed marked differences, including pathways related to sterile inflammation and inflammasome regulation. fXai but not fIIai inhibited sterile inflammation by reducing the expression of proinflammatory cytokines (IL [interleukin]-1β, IL-6, and TNFα [tumor necrosis factor alpha]), as well as NF-κB (nuclear factor kappa B) and inflammasome activation. This anti-inflammatory effect was associated with reduced myocardial fibrosis 28 days post-myocardial ischemia-reperfusion injury. Mechanistically, in vivo aPC generation was higher with fXai than with fIIai. Inhibition of the anticoagulant and signaling properties of aPC abolished the anti-inflammatory effect associated with fXai, while inhibiting only the anticoagulant function of aPC had no effect. Combining 3K3A-aPC with fIIai reduced the inflammatory response, mimicking the fXai-associated effect., Conclusions: We showed that specific inhibition of coagulation via direct oral anticoagulants had differential effects on gene expression and inflammation, despite comparable anticoagulant effects and infarct sizes. Targeting individual coagulation proteases induces specific cellular responses unrelated to their anticoagulant effect.

Background: Studies examining the role of factor V Leiden among patients at higher risk of atherothrombotic events, such as those with established coronary heart disease (CHD), are lacking. Given that coagulation is involved in the thrombus formation stage on atherosclerotic plaque rupture, we hypothesized that factor V Leiden may be a stronger risk factor for atherothrombotic events in patients with established CHD., Methods: We performed an individual-level meta-analysis including 25 prospective studies (18 cohorts, 3 case-cohorts, 4 randomized trials) from the GENIUS-CHD (Genetics of Subsequent Coronary Heart Disease) consortium involving patients with established CHD at baseline. Participating studies genotyped factor V Leiden status and shared risk estimates for the outcomes of interest using a centrally developed statistical code with harmonized definitions across studies. Cox proportional hazards regression models were used to obtain age- and sex-adjusted estimates. The obtained estimates were pooled using fixed-effect meta-analysis. The primary outcome was composite of myocardial infarction and CHD death. Secondary outcomes included any stroke, ischemic stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality., Results: The studies included 69 681 individuals of whom 3190 (4.6%) were either heterozygous or homozygous (n=47) carriers of factor V Leiden. Median follow-up per study ranged from 1.0 to 10.6 years. A total of 20 studies with 61 147 participants and 6849 events contributed to analyses of the primary outcome. Factor V Leiden was not associated with the combined outcome of myocardial infarction and CHD death (hazard ratio, 1.03 [95% CI, 0.92-1.16]; I 2 =28%; P -heterogeneity=0.12). Subgroup analysis according to baseline characteristics or strata of traditional cardiovascular risk factors did not show relevant differences. Similarly, risk estimates for the secondary outcomes including stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality were also close to identity., Conclusions: Factor V Leiden was not associated with increased risk of subsequent atherothrombotic events and mortality in high-risk participants with established and treated CHD. Routine assessment of factor V Leiden status is unlikely to improve atherothrombotic events risk stratification in this population.

Background and Purpose: Periventricular white matter hyperintensities (WMH; PVWMH) and deep WMH (DWMH) are regional classifications of WMH and reflect proposed differences in cause. In the first study, to date, we undertook genome-wide association analyses of DWMH and PVWMH to show that these phenotypes have different genetic underpinnings., Methods: Participants were aged 45 years and older, free of stroke and dementia. We conducted genome-wide association analyses of PVWMH and DWMH in 26,654 participants from CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology), ENIGMA (Enhancing Neuro-Imaging Genetics Through Meta-Analysis), and the UKB (UK Biobank). Regional correlations were investigated using the genome-wide association analyses -pairwise method. Cross-trait genetic correlations between PVWMH, DWMH, stroke, and dementia were estimated using LDSC., Results: In the discovery and replication analysis, for PVWMH only, we found associations on chromosomes 2 ( NBEAL ), 10q23.1 ( TSPAN14/FAM231A ), and 10q24.33 ( SH3PXD2A). In the much larger combined meta-analysis of all cohorts, we identified ten significant regions for PVWMH: chromosomes 2 (3 regions), 6, 7, 10 (2 regions), 13, 16, and 17q23.1. New loci of interest include 7q36.1 ( NOS3 ) and 16q24.2. In both the discovery/replication and combined analysis, we found genome-wide significant associations for the 17q25.1 locus for both DWMH and PVWMH. Using gene-based association analysis, 19 genes across all regions were identified for PVWMH only, including the new genes: CALCRL (2q32.1), KLHL24 (3q27.1), VCAN (5q27.1), and POLR2F (22q13.1). Thirteen genes in the 17q25.1 locus were significant for both phenotypes. More extensive genetic correlations were observed for PVWMH with small vessel ischemic stroke. There were no associations with dementia for either phenotype., Conclusions: Our study confirms these phenotypes have distinct and also shared genetic architectures. Genetic analyses indicated PVWMH was more associated with ischemic stroke whilst DWMH loci were implicated in vascular, astrocyte, and neuronal function. Our study confirms these phenotypes are distinct neuroimaging classifications and identifies new candidate genes associated with PVWMH only.

Background: Community-acquired pneumonia and associated sepsis cause high mortality despite antibiotic treatment. Uncontrolled inflammatory host responses contribute to the unfavorable outcome by driving lung and extrapulmonary organ failure. The complement fragment C5a holds significant proinflammatory functions and is associated with tissue damage in various inflammatory conditions. The authors hypothesized that C5a concentrations are increased in pneumonia and C5a neutralization promotes barrier stabilization in the lung and is protective in pneumococcal pulmonary sepsis., Methods: The authors investigated regulation of C5a in pneumonia in a prospective patient cohort and in experimental pneumonia. Two complementary models of murine pneumococcal pneumonia were applied. Female mice were treated with NOX-D19, a C5a-neutralizing L-RNA-aptamer. Lung, liver, and kidney injury and the inflammatory response were assessed by measuring pulmonary permeability (primary outcome), pulmonary and blood leukocytes, cytokine concentrations in lung and blood, and bacterial load in lung, spleen, and blood, and performing histologic analyses of tissue damage, apoptosis, and fibrin deposition (n = 5 to 13)., Results: In hospitalized patients with pneumonia (n = 395), higher serum C5a concentrations were observed compared to healthy subjects (n = 24; 6.3 nmol/l [3.9 to 10.0] vs. 4.5 nmol/l [3.8 to 6.6], median [25 to 75% interquartile range]; difference: 1.4 [95% CI, 0.1 to 2.9]; P = 0.029). Neutralization of C5a in mice resulted in lower pulmonary permeability in pneumococcal pneumonia (1.38 ± 0.89 vs. 3.29 ± 2.34, mean ± SD; difference: 1.90 [95% CI, 0.15 to 3.66]; P = 0.035; n = 10 or 11) or combined severe pneumonia and mechanical ventilation (2.56 ± 1.17 vs. 7.31 ± 5.22; difference: 4.76 [95% CI, 1.22 to 8.30]; P = 0.011; n = 9 or 10). Further, C5a neutralization led to lower blood granulocyte colony-stimulating factor concentrations and protected against sepsis-associated liver injury., Conclusions: Systemic C5a is elevated in pneumonia patients. Neutralizing C5a protected against lung and liver injury in pneumococcal pneumonia in mice. Early neutralization of C5a might be a promising adjunctive treatment strategy to improve outcome in community-acquired pneumonia.

Background: The Genetics of Subsequent Coronary Heart Disease (GENIUS-CHD) consortium was established to facilitate discovery and validation of genetic variants and biomarkers for risk of subsequent CHD events, in individuals with established CHD., Methods: The consortium currently includes 57 studies from 18 countries, recruiting 185 614 participants with either acute coronary syndrome, stable CHD, or a mixture of both at baseline. All studies collected biological samples and followed-up study participants prospectively for subsequent events., Results: Enrollment into the individual studies took place between 1985 to present day with a duration of follow-up ranging from 9 months to 15 years. Within each study, participants with CHD are predominantly of self-reported European descent (38%-100%), mostly male (44%-91%) with mean ages at recruitment ranging from 40 to 75 years. Initial feasibility analyses, using a federated analysis approach, yielded expected associations between age (hazard ratio, 1.15; 95% CI, 1.14-1.16) per 5-year increase, male sex (hazard ratio, 1.17; 95% CI, 1.13-1.21) and smoking (hazard ratio, 1.43; 95% CI, 1.35-1.51) with risk of subsequent CHD death or myocardial infarction and differing associations with other individual and composite cardiovascular endpoints., Conclusions: GENIUS-CHD is a global collaboration seeking to elucidate genetic and nongenetic determinants of subsequent event risk in individuals with established CHD, to improve residual risk prediction and identify novel drug targets for secondary prevention. Initial analyses demonstrate the feasibility and reliability of a federated analysis approach. The consortium now plans to initiate and test novel hypotheses as well as supporting replication and validation analyses for other investigators.

Background: Genetic variation at chromosome 9p21 is a recognized risk factor for coronary heart disease (CHD). However, its effect on disease progression and subsequent events is unclear, raising questions about its value for stratification of residual risk., Methods: A variant at chromosome 9p21 (rs1333049) was tested for association with subsequent events during follow-up in 103 357 Europeans with established CHD at baseline from the GENIUS-CHD (Genetics of Subsequent Coronary Heart Disease) Consortium (73.1% male, mean age 62.9 years). The primary outcome, subsequent CHD death or myocardial infarction (CHD death/myocardial infarction), occurred in 13 040 of the 93 115 participants with available outcome data. Effect estimates were compared with case/control risk obtained from the CARDIoGRAMplusC4D consortium (Coronary Artery Disease Genome-wide Replication and Meta-analysis [CARDIoGRAM] plus The Coronary Artery Disease [C4D] Genetics) including 47 222 CHD cases and 122 264 controls free of CHD., Results: Meta-analyses revealed no significant association between chromosome 9p21 and the primary outcome of CHD death/myocardial infarction among those with established CHD at baseline (GENIUS-CHD odds ratio, 1.02; 95% CI, 0.99-1.05). This contrasted with a strong association in CARDIoGRAMPlusC4D odds ratio 1.20; 95% CI, 1.18-1.22; P for interaction <0.001 compared with the GENIUS-CHD estimate. Similarly, no clear associations were identified for additional subsequent outcomes, including all-cause death, although we found a modest positive association between chromosome 9p21 and subsequent revascularization (odds ratio, 1.07; 95% CI, 1.04-1.09)., Conclusions: In contrast to studies comparing individuals with CHD to disease-free controls, we found no clear association between genetic variation at chromosome 9p21 and risk of subsequent acute CHD events when all individuals had CHD at baseline. However, the association with subsequent revascularization may support the postulated mechanism of chromosome 9p21 for promoting atheroma development.

Background: Inhibition of PCSK9 (proprotein convertase subtilisin/kexin type 9) is a novel strategy to treat hypercholesterolemia and reduce cardiovascular events. However, the potential role of circulating plasma PCSK9 concentrations as a diagnostic and predictive biomarker remains uncertain as of now. Here, we aimed to identify genetic variants associated with plasma PCSK9 and investigate possible causal effects on atherosclerotic vascular disease phenotypes., Methods: We performed the first genome-wide association study of plasma PCSK9 levels in a cohort of suspected and confirmed coronary artery disease (LIFE-Heart; n=3290)., Results: Several independent variants at the PCSK9 gene locus were associated with circulating PCSK9 levels at genome-wide significance (lead SNP rs11591147, PCSK9-R46L; P =1.94×10 -17 ). We discovered 4 independent PCSK9 SNPs explaining 4.4% of the variance of plasma PCSK9. In addition, we identified a genome-wide significant locus at chromosome 7p22.1 (rs6957201; P =7.01×10 -9 ) and 7 suggestive hits ( P <1×10 -6 ). Using MR (Mendelian Randomization), we detected significant causal effects of circulating PCSK9 on coronary artery disease status and severity, carotid plaques, and intima-media thickness., Conclusions: Variants at the PCSK9 gene locus seem to be the major genetic determinants of plasma PCSK9 levels with 4 independent variants at the PCSK9 gene locus expressing allelic heterogeneity. The detected MR estimates support the hypothesis of a causal effect of PCSK9 on coronary artery disease and other vascular phenotypes. Other observed genetic associations for PCSK9 require validation in independent cohorts., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00497887., (© 2018 American Heart Association, Inc.)

Most atlas fractures are the result of compression forces. They are often combined with fractures of the axis and especially with the odontoid process. Multiple classification systems for atlas fractures have been described. For an adequate diagnosis, a computed tomography is mandatory. To distinguish between stable and unstable atlas injury, it is necessary to evaluate the integrity of the transverse atlantal ligament (TAL) by magnetic resonance imaging and to classify the TAL lesion. Studies comparing conservative and operative management of unstable atlas fractures are unfortunately not available in the literature; neither are studies comparing different operative treatment strategies. Hence all treatment recommendations are based on low level evidence. Most of atlas fractures are stable and will be successfully managed by immobilization in a soft/hard collar. Unstable atlas fractures may be treated conservatively by halo-fixation, but nowadays more and more surgeons prefer surgery because of the potential discomfort and complications of halo-traction. Atlas fractures with a midsubstance ligamentous disruption of TAL or severe bony ligamentous avulsion can be treated by a C1/2 fusion. Unstable atlas fractures with moderate bony ligamentous avulsion may be treated by atlas osteosynthesis. Although the evidence for the different treatment strategies of atlas fractures is low, atlas osteosynthesis has the potential to change treatment philosophies. The reasons for this are described in this review.

Pulse wave velocity (PWV) and augmentation index (AI) are independent predictors of cardiovascular health. However, the comparability of multiple oscillometric modalities currently available for their assessment was not studied in detail. In the present study, we aimed to evaluate the relationship between indices of arterial stiffness assessed by diastolic and suprasystolic oscillometry.In total, 56 volunteers from the general population (23 males; median age 70 years [interquartile range: 65-72 years]) were recruited into observational feasibility study to evaluate the carotid-femoral/aortic PWV (cf/aoPWV), brachial-ankle PWV (baPWV), and AI assessed by 2 devices: Vicorder (VI) applying diastolic, right-sided oscillometry for the determination of all 3 indices, and Vascular explorer (VE) implementing single-point, suprasystolic brachial oscillometry (SSBO) pulse wave analysis for the assessment of cfPWV and AI. Within- and between-device correlations of measured parameters were analyzed. Furthermore, agreement of repeated measurements, intra- and inter-observer concordances were determined and compared for both devices.In VI, both baPWV and cfPWV inter-correlated well and showed good level of agreement with bilateral baPWV measured by VE (baPWV[VI]-baPWV[VE]R: overall concordance correlation coefficient [OCCC] = 0.484, mean difference = 1.94 m/s; cfPWV[VI]-baPWV[VE]R: OCCC = 0.493, mean difference = 1.0 m/s). In contrast, SSBO-derived aortic PWA (cf/aoPWA[VE]) displayed only weak correlation with cfPWV(VI) (r = 0.196; P = 0.04) and ipsilateral baPWV (cf/aoPWV[VE]R-baPWV[VE]R: r = 0.166; P = 0.08). cf/aoPWA(VE) correlated strongly with AI(VE) (right-sided: r = 0.725, P < 0.001). AI exhibited marginal between-device agreement (right-sided: OCCC = 0.298, mean difference: 6.12%). All considered parameters showed good-to-excellent repeatability giving OCCC > 0.9 for 2-point-PWV modes and right-sided AI(VE). Intra- and inter-observer concordances were similarly high except for AI yielding a trend toward better reproducibility in VE (interobserver-OCCC[VI] vs [VE] = 0.774 vs 0.844; intraobserver-OCCC[VI] vs [VE] = 0.613 vs 0.769).Both diastolic oscillometry-derived PWV modes, and AI measured either with VI or VE, are comparable and reliable alternatives for the assessment of arterial stiffness. Aortic PWV assessed by SSBO in VE is not related to the corresponding indices determined by traditional diastolic oscillometry., Competing Interests: The authors have no conflicts of interest to disclose.

Study Design: In vitro biomechanical analysis of different multilevel cervical fixation techniques., Objective: To compare the multilevel stability of a cervical anchored spacer (AS) with established fixation techniques., Summary of Background Data: To avoid plate-related complications, for example, dysphagia zero-profile AS has been developed. The use of these new zero-profile implants for treatment of cervical degenerative disc disease is widely accepted after encouraging biomechanical results for single-level instrumentation. However, there is only little knowledge about the biomechanical stability of these zero-profile devices in multilevel instrumentations., Methods: Eight fresh-frozen human cadaveric cervical spines (C3-C7) were nondestructively tested in a biomechanical 3-dimensional spine test setup. Segmental range of motion (ROM) under torsional load of 1.5 N·m was measured optoelectronically. Intact spine baseline measurement specimens were tested with 2- and 3-level instrumentation including (1) stand-alone PEEK-cage; (2) PEEK-cage plus locking plate; and (3) AS. Repeated-measures analyses of variance were used for statistical analysis., Results: Comparison of baseline ROM and stand-alone PEEK-cage instrumentation showed a significant lower segmental ROM only for 2-level instrumentations. Cage plus plate and AS were able to reduce segmental ROM significantly (P < 0.05) in 2- and 3-level instrumentations. Comparing cage plus plate and AS, a significant lower ROM was detected for flexion/extension in 2- and 3-level instrumentation and for lateral bending in 2-level instrumentation using cage plus plate., Conclusion: Segmental stability decreases with the number of instrumented segments regardless of the used implant. Comparing the different fixation techniques biomechanically, the locking plate and cage construct was stiffer in all test modes than the anchored devices in multilevel constructs. However, it remains unclear what the clinical significance may be., Level of Evidence: N/A.

Study Design: Radiological and histological assessment of fusion status after anterior cervical discectomy and fusion (ACDF) procedure in a sheep spinal fusion model., Objective: To evaluate the efficacy of cyclic arginine-glycine-aspartic (cRGD) in comparison with recombinant human bone morphogenetic protein-2 (rhBMP-2) on a mineralized collagen matrix (MCM)., Summary of Background Data: A previous evaluation of MCM alone in comparison with autologous bone graft alone was not able to show an advantage on spinal fusion. The cRGD peptide sequence plays a major role in mediating cell adhesion. Studies have demonstrated enhances osteoblasts adhesion resulting in increased periimplant bone formation after implantcoating with cRGD. rhBMP-2 has already proven its ability to enhance spinal fusion. To date, no comparative in vivo evaluation of cRGD and rhBMP-2 in combination with a MCM for spinal fusion has been performed., Methods: Twenty-four sheep (N = 8/group) underwent C3-C4 fusion. Implants: group 1: titanium cage with MCM and rhBMP-2; group 2: titanium cage with MCM and cRGD; control group: titanium cage with MCM alone. After 12 weeks fusion sites were evaluated by computed tomography to assess fusion status, bone mineral density as well as bony callus volume. Furthermore, histomorphological and histomorphometrical analysis of the fusion sites were performed., Results: In comparison with the control group, cRGD, and rhBMP-2 groups showed a higher fusion rate in radiographical findings and a higher degree of interbody fusion in histomorphometrical analysis (P < 0.05). There was no significant difference in radiographical and histological parameters between the rhBMP-2 and the cRGD group. Although rhBMP-2 demonstrated ectopic prevertebral bone formations, this effect was less prominent in the cRGD group., Conclusion: In this animal model the combination of cRGD and a mineralized collagen matrix showed superior fusion results in comparison with the mineralized collagen alone. Further, cRGD was comparably effective to rhBMP-2 in promoting interbody fusion by demonstrating less ectopic bone formations.

Background: Intraoperative fluorescence angiography has been reported to be a promising method, with rapid and high-quality image production at low cost when used for the detection of microvascular complications. The purpose of this study was to evaluate the reliability of intraoperative near-infrared indocyanine green angiography compared with microvascular Doppler testing in a standardized model in the rat with different vessel patencies., Methods: The carotid, aorta, and femoral vessels of 23 Wistar rats were used. Indocyanine green angiography and microvascular Doppler sonographic testing were performed to assess microanastomosis with a vessel patency randomly narrowed at the anastomosis to an outer patency of 100, 75, 50, 25, and 0 percent., Results: A total of 424 investigations were performed for 68 anastomoses, including both indocyanine green videoangiographic and microvascular Doppler sonographic examinations. The overall sensitivity and specificity of the microvascular Doppler sonographic testing at different degrees of stenoses were 100 and 86.9 percent, respectively. The positive predictive value for all observations was 95.8 percent, and the corresponding negative predictive value was 100 percent. Indocyanine green angiography revealed an overall sensitivity of 95.3 percent and a specificity of 100 percent. The positive predictive value for these observations was 100 percent, and the negative predictive value was 84 percent., Conclusions: Indocyanine green angiography and microvascular Doppler sonography are quick and reliable methods for assessing blood flow in vessels in the laboratory model. The combined use of indocyanine green angiography and microvascular Doppler sonography can increase the accuracy of assessment of microvascular anastomoses intraoperatively. Indocyanine green can be used first, but followed by the microvascular Doppler in cases of a negative result to maximize accuracy.

Background: Phytosterols are plant-derived sterols that are taken up from food and can serve as biomarkers of cholesterol uptake. Serum levels are under tight genetic control. We used a genomic approach to study the molecular regulation of serum phytosterol levels and potential links to coronary artery disease (CAD)., Methods and Results: A genome-wide association study for serum phytosterols (campesterol, sitosterol, brassicasterol) was conducted in a population-based sample from KORA (Cooperative Research in the Region of Augsburg) (n=1495) with subsequent replication in 2 additional samples (n=1157 and n=1760). Replicated single-nucleotide polymorphisms (SNPs) were tested for association with premature CAD in a metaanalysis of 11 different samples comprising 13 764 CAD cases and 13 630 healthy controls. Genetic variants in the ATP-binding hemitransporter ABCG8 and at the blood group ABO locus were significantly associated with serum phytosterols. Effects in ABCG8 were independently related to SNPs rs4245791 and rs41360247 (combined P=1.6 x 10(-50) and 6.2 x 10(-25), respectively; n=4412). Serum campesterol was elevated 12% for each rs4245791 T-allele. The same allele was associated with 40% decreased hepatic ABCG8 mRNA expression (P=0.009). Effects at the ABO locus were related to SNP rs657152 (combined P=9.4x10(-13)). Alleles of ABCG8 and ABO associated with elevated phytosterol levels displayed significant associations with increased CAD risk (rs4245791 odds ratio, 1.10; 95% CI, 1.06 to 1.14; P=2.2 x 10(-6); rs657152 odds ratio, 1.13; 95% CI, 1.07 to 1.19; P=9.4 x 10(-6)), whereas alleles at ABCG8 associated with reduced phytosterol levels were associated with reduced CAD risk (rs41360247 odds ratio, 0.84; 95% CI, 0.78 to 0.91; P=1.3 x 10(-5))., Conclusion: Common variants in ABCG8 and ABO are strongly associated with serum phytosterol levels and show concordant and previously unknown associations with CAD.

Study Design: After anterior cervical discectomy, fusion was radiologically, biomechanically, and histologically assessed in a sheep spine fusion model., Objective: To evaluate the efficacy of a platelet-rich plasma (PRP) application combined with a mineralized collagen matrix (MCM) as an alternative to autologous cancellous iliac crest bone grafts in a spine fusion model., Summary of Background Data: PRP has the ability to stimulate bone and tissue healing. MCM is a recently developed osteoconductive material. Up to now, no comparative evaluation of PRP in combination with a MCM at the cervical spine has been performed in vivo., Methods: Twenty-four sheep (N = 8/group) underwent C3/4 discectomy and fusion: group 1, titanium cage filled with autologous cancellous iliac crest bone graft; group 2, titanium cage filled with MCM; and group 3, titanium cage filled with MCM and PRP. Radiographic evaluation was performed before surgery and after 1, 2, 4, 8, and 12 weeks, respectively. After 12 weeks, fusion sites were evaluated using functional radiographic views and quantitative computed tomographic scans to assess bone mineral density. Furthermore, histomorphologic and histomorphometrical analyses were performed to evaluate fusion., Results: In comparison with the titanium cage group filled with autologous cancellous iliac crest bone grafts representing the control group, MCM-alone group showed a slightly lower fusion rate in the radiographic and the histomorphometrical analysis. The addition of PRP could not enhance this finding. There was no significant difference between MCM and MCM + PRP group in radiologic and histologic findings., Conclusion: The MCM alone is not able to replace autologous bone grafts. Early activation of the platelets by calcium, which is released from mineralized collagen, could be the reason for the insufficient osteoinductive effect of PRP. In consequence, the combined application of mineralized collagen and PRP had no significant osteoinductive effect in this model.

Objective: We tested the hypothesis that expression of transcripts adjacent to the chromosome 9p21 (Chr9p21) locus of coronary artery disease was affected by the genotype at this locus and associated with atherosclerosis risk., Methods and Results: We replicated the locus for coronary artery disease (P=0.007; OR=1.28) and other manifestations of atherosclerosis such as carotid plaque (P=0.003; OR=1.31) in the Leipzig Heart Study, a cohort of 1134 patients with varying degree of angiographically assessed coronary artery disease. Expression analysis in peripheral blood mononuclear cells (n=1098) revealed that transcripts EU741058 and NR&#95;003529 of antisense noncoding RNA in the INK4 locus (ANRIL) were significantly increased in carriers of the risk haplotype (P=2.1x10(-12) and P=1.6x10(-5), respectively). In contrast, transcript DQ485454 remained unaffected, suggesting differential expression of ANRIL transcripts at Chr9p21. Results were replicated in whole blood (n=769) and atherosclerotic plaque tissue (n=41). Moreover, expression of ANRIL transcripts was directly correlated with severity of atherosclerosis (EU741058 and NR&#95;003529; P=0.02 and P=0.001, respectively). No consistent association of Chr9p21 or atherosclerosis was found with expression of other genes such as CDKN2A, CDKN2B, C9orf53, and MTAP., Conclusions: Our data provide robust evidence for an association of ANRIL but not CDKN2A, CDKN2B, C9orf53, and MTAP, with atherosclerosis and Chr9p21 genotype in a large cohort.

Kynurenine, the major degradation product of tryptophan has been shown to directly damage tissues, but its possible contribution to posttraumatic morbidity is unknown. Here, we studied the kinetics of kynurenine in patients after major trauma and whether this correlates with the development of posttraumatic sepsis. Kynurenine and tryptophan levels of 60 multiple-injured patients with Injury Severity Score of more than 16 were quantified prospectively by high-performance liquid chromatography. Blood samples were obtained daily from admission until day 10 after admission. Significantly increased kynurenine values were detectable already at day 1 after admission in blood from patients who later developed sepsis, regardless of injury pattern (P < 0.01). In contrast, kynurenine values of nonsepsis patients remained low throughout the observation period. However, all patients exhibited significantly decreased tryptophan values versus healthy controls (P < 0.01). Moreover, significantly increased kynurenine-tryptophan ratios rapidly predicted subsequent sepsis, multiple organ failure, and death (P < 0.01). Both increased kynurenine values and kynurenine-tryptophan ratios predicted posttraumatic development of sepsis and organ failure. This ought to be validated in subsequent studies.

Study Design: A prospective analysis., Objective: The idea of this study was to evaluate a new miniature robotic system providing passive guidance for pedicle screw placement at the lumbar spine. Special focus was laid on the postoperative accuracy of screw placement., Summary and Background Data: Recent technical developments lead to a minimization of pedicle screw fixation techniques. However, the use of navigational techniques is still under controversy., Methods: Patients selected for a minimal invasive posterior lumbar interbody fusion received a spiral computer tomographic scan before surgery. The miniature hexapod robot was mounted to the spinous process and the system moves to the exact entry point according to the trajectory of the surgeon's preoperative plan. After minimal invasive screw placement all patients received routinely a postoperative spiral computer tomographic scan. Screws placed exactly within the pedicle were evaluated as group A, screws deviating <2 mm were evaluated as group B, > or =2 mm to <4 mm (group C); > or =4 mm to <6 mm (group D); and more than 6 mm (group E)., Results: Thirty-one patients received a PLIF with percutaneous posterior pedicle screw insertion using the bone mounted miniature robotic device. A total of 133 pedicle screws were placed. The majority of the screws were placed in L5 (58 screws; 43.6%). In axial plane, 91.7% of the screws were evaluated as group A and 6.8% were evaluated as group B. In longitudinal plane, 81.2% of the screws were evaluated as group A and 9.8% were evaluated as group B. In 1 screw (L5 right) the postoperative evaluation was done as group C (axial plane) and D (longitudinal plane). In 29/31 cases the integration of the miniature robotic system was successful., Conclusion: In our study the first clinical assessment of a new bone mounted robot system guiding percutaneous pedicle screw placement was done. A deviation <2 mm to the surgeon 's plan in 91.0% to 98.5% verifies the system's accuracy.

Objectives: Granulocyte transfusions have been used to treat immune cell dysfunction in sepsis. As granulocyte transfusions can trigger tissue injury via local effects of neutrophils, we hypothesized that extracorporeal treatment of plasma using granulocytes would prove beneficial while having less side effects., Design: Prospective controlled three-armed animal study., Setting: Research laboratory., Subjects: Twenty-one female immature pigs (7.5-12 kg, 7-9 weeks old)., Interventions: Three groups of spontaneously breathing, sedated pigs (n = 7 each) received an intravenous lethal dose of live Staphylococcus aureus over 1 hour. Although group I had no specific treatment (control), group II and III were subsequently treated for 4 hours with an extracorporeal device containing either no cells (sham control, group II) or human cell line-derived granulocytic cells (group III). Survival time and physiologic, biochemical, and hematologic parameters were monitored for 7 days., Measurements and Main Results: All animals of group I died during the observation time (mean survival time: 70 hours). In group II, two of seven and in group III, six of seven animals survived the observation time (mean survival: 75 and 168 hours, respectively). Survival differences were significant between group I and III (p < 0.001) and between group II and III (p < 0.05) but not between group I and II (p = 0.43). Furthermore, group differences in bacterial blood concentrations, differential blood count, blood gases, lactate, and interleukins were observed. The extracorporeal cell treatment was well tolerated by the animals., Conclusions: Extracorporeal therapy with granulocytic cells significantly improved survival in a pig model of sepsis. Further studies with this approach are encouraged.

Study Design: A new anchored spacer-a low-profile cervical interbody fusion cage with integrated anterior fixation-was compared biomechanically to established anterior cervical devices., Objective: To evaluate the fixation properties of the new stand-alone device and compare these properties with established fixation methods. The hypothesis is that the new device will provide stability comparable to that provided by an anterior cervical cage when supplemented with an anterior plate., Summary of Background Data: It is accepted that the use of anterior cervical plating increases the chance of achieving a solid fusion. However, its use may be associated with an increase in operation time and a higher postoperative morbidity caused by a larger anterior approach and disruption of the anterior musculature. This dilemma has led to the development of a new, low profile stand-alone cervical anterior cage device with integrated screw fixation., Methods: Twenty-four human cadaveric C4-C7 cervical spines were loaded nondestructively with pure moments in a nonconstraining testing apparatus to induce flexion, extension, lateral bending, and axial rotation while angular motion was measured optoelectronically. The specimens were tested: 1. Intact (N = 24). 2. After discectomy and anterior stabilization. a. Interbody cage + locking plate (N = 8). b. Interbody cage + dynamic plate (N = 8). c. Anchored spacer (N = 8). 3. After ventral plate removal of group 2a and 2b (N = 16)., Results: All fixation techniques decreased range of motion (ROM) and lax zone (LZ) (P < 0.05) in all test modes compared with the intact motion segment and cage-only group. There were no significant differences between the anchored spacer and cage + locking plate or cage + dynamic plate., Conclusion: The anchored spacer provided a similar biomechanical stability to that of the established anterior fusion technique using an anterior plate plus cage and has a potentially lower perioperative and postoperative morbidity. These results support progression to clinical trials using the cervical anchored spacer as a stand-alone implant.

The release of "neutrophil extracellular traps" (NETs) has been identified as a novel immune response in innate immunity. Neutrophil extracellular traps are composed of neutrophil-derived circulating free DNA (cf-DNA), histones, and neutrophil cytoplasm-derived proteins such as proteases. Here, we studied the putative predictive value of plasma cf-DNA/NETs for the development of sepsis and mortality after multiple trauma. In a prospective pilot study with 45 multiple trauma (Injury Severity Score>16) patients, cf-DNA was directly quantified in plasma. Blood samples were sequentially obtained daily from admission to our Trauma Center until day 10. Because of limited intensive care unit (ICU) stay of less than 3 days, 8 patients have been excluded, resulting in 37 patients that were evaluated. Time kinetics of cf-DNA/NETs was compared with C-reactive protein (CRP), interleukin (IL) 6, leukocyte counts, and myeloperoxidase. The severity of the injury was calculated on the basis of the Injury Severity Score, as well as Multiple Organ Dysfunction Score, Sequential Organ Failure Assessment, and Simplified Acute Physiology Score II on ICU. Initially high cf-DNA/NETs values (>800 ng/mL) with recurrent increased values between days 5 to 9 were associated with subsequent sepsis, multiple organ failure, and death. In conjunction with cf-DNA/NETs, IL-6 was significantly elevated after admission. However, the development of a second hit was not indicated by IL-6. In contrast to cf-DNA/NETs, no difference in CRP kinetics was observed between patients with and without development of sepsis. Circulating free DNA/NETs kinetics rather followed kinetics of Multiple Organ Dysfunction Score, Sepsis-related Organ Failure Assessment, leukocyte counts, and partially of myeloperoxidase. Circulating free DNA/NETs seems to be a valuable additional marker for the calculation of injury severity and/or prediction of inflammatory second hit on ICU. However, a large clinical trial with severely injured patients should confirm the prognostic value of neutrophil-derived cf-DNA/NETs.

Background: The authors compared the safety and efficacy of a newly developed fast-track concept at their center, including implementation of a direct admission postanesthetic care unit, to standard perioperative management., Methods: All fast-track patients treated within the first 6 months of implementation of our direct admission postanesthetic care unit were matched via propensity scores and compared with a historical control group of patients who underwent cardiac surgery prior to fast-track implementation., Results: A total of 421 fast-track patients were matched successfully to 421 control patients. The two groups of patients had a similar age (64 +/- 13 vs. 64 +/- 12 yr for fast-track vs. control, P = 0.45) and European System for Cardiac Operative Risk Evaluation-predicted risk of mortality (4.8 +/- 6.1% vs. 4.6 +/- 5.1%, P = 0.97). Fast-track patients had significantly shorter times to extubation (75 min [45-110] vs. 900 min [600-1140]), as well as shorter lengths of stay in the postanesthetic or intensive care unit (4 h [3.0-5] vs. 20 h [16-25]), intermediate care unit (21 h [17-39] vs. 26 h [19-49]), and hospital (10 days [8-12] vs. 11 days [9-14]) (expressed as median and interquartile range, all P < 0.01). Fast-track patients also had a lower risk of postoperative low cardiac output syndrome (0.5% vs. 2.9%, P < 0.05) and mortality (0.5% vs. 3.3%, P < 0.01)., Conclusion: The Leipzig fast-track protocol is a safe and effective method to manage cardiac surgery patients after a variety of operations.

Study Design: Established lumbar fixation methods were assessed biomechanically, and a comparison was made with a new stand-alone anterior lumbar interbody cage device incorporating integrated anterior fixation., Objectives: To compare the stability of a new stand-alone anterior implant (Test-device) with established fixation methods to assess its suitability for clinical use. Our hypothesis being that the Test-device would provide stability comparable to that provided by an anterior cage when supplemented with posterior pedicle screw fixation., Summary of Background Data: It is accepted that the use of rigid pedicle screw instrumentation increases the chance of achieving a solid fusion, but its use may be associated with a significant increase in postoperative morbidity caused by disruption of the posterior musculature. It is also evident that this increased fusion rate is generally not associated with increased clinical success. This dilemma has led to a search for a solution and to the development of the Test-device anterior lumbar interbody device., Methods: The kinematic properties of either the L3-L4 or L4-L5 lumbar motion segment of 8 cadaveric lumbar spines have been tested using the following sequence of fixation: intact, Test-device, Test-device and translaminar facet screws (TS), Cage and TS, Cage and Universal Spine System (USS), and Cage and small stature USS., Results: All fixation techniques except the cage and TS decreased (P < 0.05) range of motion (ROM), neutral zone (NZ), and elastic zone (EZ), and increased (P < 0.05) stiffness in comparison to the intact motion segment in all test modes. There was a significant increase (P < 0.01) in the ROM, NZ, and EZ, and decrease in the stiffness of the cage and TS group in comparison to all other stabilization techniques in flexion and rotation. There was no significant difference in the ROM, NZ, EZ, and stiffness between the Test-device and cage and USS groups in flexion, extension, and bending. The Test-device resulted in a significantly lower EZ (P < 0.05) and a significantly higher stiffness (P < 0.05) in rotation than all other fixation methods., Conclusions: The Test-device alone provided similar and the Test-device and TS higher stability than the pedicle screw constructs evaluated. These results support progression to clinical trials using the Test-device as a stand-alone implant.

Systemic administration of immune modulating antibodies may play an important role in reducing neutrophil hyperactivity, for example, in patients undergoing cardiac surgery with extracorporeal circulation or in trauma patients. However, this strategy has extremely high costs and is often associated with severe adverse effects. We developed the Leukocyte-Inhibition-Module (LIM), an extracorporeal circulation (ECC) device housing a polyurethane matrix with covalently bound Fas (CD95; APO-1) stimulating antibodies to rapidly prevent neutrophil hyperactivation. A feasibility study with 14 patients undergoing cardiac surgery with the use of immunogenic ECC without (n = 5) and with (n = 9) LIM (venous line) was performed. Our data show that the usually observed ECC associated perioperative increase in neutrophils (control) was prevented by LIM (p = 0.023). Moreover, the increase of the proinflammatory markers tumor necrosis factor (TNF)-alpha and polymorphonuclear elastase was limited by LIM (p = 0.038 and p = 0.002). In both groups, no significant changes in liver enzymes or in clotting were detected after surgery, and up to 12 months follow up, no unusual complications were reported. This study shows for the first time to our knowledge the feasibility, efficacy, and safety of a new cost effective, immune management strategy in patients with aberrant immune activation by exposing the blood stream to immobilized agonistic anti-Fas antibodies.

Study Design: An in vitro study was conducted to determine the biomechanical properties of a new simple, percutaneous, posterior fixation technique for the lumbar spine involving a new implant, the so-called Lumbar Facet Interference Screw., Objectives: The purpose of this study was to compare the biomechanical properties of this new fixation device with translaminar and pedicle screw fixation., Summary of Background Data: Several techniques were described to perform a minimal invasive posterior stabilization of the lumbar spine after an anterior lumbar interbody fusion procedure. Yet, due to the high complexity of these minimally invasive surgical procedures, currently, hardly any of these percutaneous posterior fixation techniques is carried out routinely., Methods: Ten human lumbar spines were tested in flexion, extension, axial rotation, and lateral bending using a nonconstrained testing method. First, all motion segments were evaluated intact (group 1). After complete discectomy of L4-L5, the following stabilization techniques were tested sequentially (n = 10/group): group 2: "stand-alone" cage; group 3: cage plus translaminar screws; group 4: cage plus Lumbar Facet Interference Screw; and group 5: cage plus pedicle screws. Stiffness, ranges of motion, and neutral and elastic zones were determined., Results: In comparison to the intact motion segment, the "stand-alone" cage showed a significantly higher (P < 0.05) range of motion, neutral zone, and elastic zone and a significantly lower (P < 0.05) stiffness in extension and rotation. Generally, all fixation techniques using cages plus posterior stabilization decreased range of motion, neutral zone, and elastic zone and increased stiffness in comparison to the "stand-alone" cage group. There was no significant difference between the cage plus interference screw and the cage plus translaminar screw group in all test modes. In comparison to the 2 facet joint stabilization techniques, pedicle screw stabilization decreased (P < 0.01) range of motion, neutral zone, and elastic zone and increased (P < 0.01) stiffness significantly in flexion and rotation., Conclusions: Results of this study indicate that the new Lumbar Facet Interference Screw fixation yields initial biomechanical stability similar to translaminar screw fixation, yet inferior biomechanical stability compared to pedicle screw fixation. Although these results are encouraging, additional biomechanical studies including cyclic loading tests have to evaluate the mid- and long-term stabilization capacity of this new minimally invasive fixation technique before human application.

Study Design: An experimental study using a sheep cervical spine interbody fusion model., Objectives: To compare interbody fusion of an autologous tricortical iliac crest bone graft with two bioabsorbable cages and to determine whether there are differences between the three interbody fusion techniques in 1) the ability to preserve postoperative distraction, 2) the biomechanical stability, and 3) the histologic characteristics of intervertebral bone matrix formation., Summary and Background Data: Bioabsorbable cages would be beneficial compared with metallic cages; however, currently no suitable bioabsorbable interbody fusion cage is available., Method: Twenty-four sheep underwent C3/C4 discectomy and fusion. The following stabilization techniques were used: Group 1) autologous tricortical iliac crest bone graft (n = 8); Group 2) bioabsorbable cage made of 70/30 poly(l-lactide-co-d,l-lactide) (experimental) filled with autologous cancellous bone graft (n = 8); Group 3) bioabsorbable cage made of a polymer-calciumphosphate composite (Biomet Europe, Dordrecht, The Netherlands) filled with autologous cancellous bone graft (n = 8). Radiographic scans to determine disc space height were performed before and after surgery and after 1, 2, 4, 8, and 12 weeks, respectively. After 12 weeks, animals were killed, and fusion sites were evaluated using functional radiographic views in flexion and extension. Quantitative computed tomographic scans were used to assess bone mineral density, bone mineral content, and bony callus volume. Biomechanical testing was performed in flexion, extension, axial rotation, and lateral bending to determine stiffness, ROM, and neutral and elastic zone. Histomorphological and histomorphometrical analysis were performed to evaluate fusion and foreign body reactions associated with the bioabsorbable cages., Results: Over a 12-week period, the polymer-calciumphosphate composite cage showed significantly higher values for disc space height compared with the bone graft and the poly(l-lactide-co-d,l-lactide) cage. Additionally, the polymer-calciumphosphate composite cage demonstrated a significantly higher stiffness and lower ROM, neutral zone, and elastic zone in axial rotation and lateral bending than any other group. However, quantitative computed tomographic scans demonstrated cracks in six of the eight polymer-calciumphosphate composite cages after 12 weeks. Histologically, the highest bone volume/total volume ratio and the highest fusion rate were found in the polymer-calciumphosphate composite cage group. Although the poly(l-lactide-co-d,l-lactide) cage showed grade I through III foreign body reactions in all fusion areas, only two animals developed grade I foreign body reactions with the polymer-calciumphosphate composite cage., Conclusion: After 12 weeks, there was no significant difference between the bioabsorbable poly(l-lactide-co-d,l-lactide) cage and the tricortical bone graft. In comparison to the tricortical bone graft, the bioabsorbable polymer-calciumphosphate composite cage showed significantly better distractive properties, a significantly higher biomechanical stiffness, and an advanced interbody fusion; however, six of eight polymer-calciumphosphate composite cages cracked. Although the fate of the foreign body reactions and the cracks is currently unclear for both bioabsorbable cages, the early appearance of large osteolysis associated with use of the poly(l-lactide-co-d,l-lactide) cage allows skepticism regarding the value of this bioabsorbable implant.

Study Design: In vitro biomechanical study of bioabsorbable cervical spine interbody fusion cages using a sheep model., Objectives: The purpose of this study was to evaluate the segmental stability provided by 2 new developed bioabsorbable cervical spine interbody fusion cages and to compare it with a tricortical iliac crest bone graft and a titanium meshed interbody fusion cage. Further, the biomechanical effect of an additional anterior plate instrumentation was determined., Summary and Background Data: Despite the initial favorable results, the long-term effects of metallic cage devices on spinal motion segments are still unknown. Furthermore, shortcomings of metallic cages like migration, adjacent level degeneration, stenotic myelopathy, and artifacts in postoperative radiologic assessment have already been reported. Bioabsorbable cages have been designed to avoid these complications. Currently, no information is available about the biomechanical properties of bioabsorbable cervical spine interbody fusion cages., Methods: Forty sheep cervical spines (C2-C5) were tested in flexion, extension, axial rotation, and lateral bending with a nondestructive stiffness method using a nonconstrained testing apparatus. First, the motion segment C3-C4 was tested intact. After complete discectomy, the following groups were evaluated: autologous iliac crest bone graft, titanium mesh cylinder (Harms, DePuy AcroMed), bioabsorbable PDLLA-cage (experimental), and bioabsorbable Resorbon cage (Biomet Merck). Further, all implants were tested with an additional anterior plate instrumentation. The mean apparent stiffness, range of motion, neutral zone, and elastic zone were calculated from the corresponding load-displacement curves., Results: No significant difference in range of motion and segmental stiffness among the tricortical iliac crest bone graft, meshed titanium Harms cage, and PDLLA-cage could be determined. The Resorbon cage significantly (P < 0.05) decreased range of motion and increased stiffness in rotation and flexion in comparisonto all tested implants and the intact motion segment. An additional anterior plate significantly (P < 0.05) decreased range of motion and increased stiffness in flexion and extension., Conclusion: In this study, bioabsorbable cages demonstrated biomechanical in vitro properties equal or superior to metallic cages. From the biomechanical point of view, bioabsorbable cages, especially the Resorbon cage, may be a viable alternative to current metallic interbody cage devices. However, animal experimental in vivo evaluation of bioabsorbable cervical spine interbody fusion cages still has to be performed.

Study Design: An in vitro biomechanical study of expandable cages for vertebral body replacement in the human thoracolumbar spine., Objectives: The purpose of this study was to compare the in vitro biomechanical properties of 3 different expandable cages with a nonexpandable cage., Summary and Background Data: Recently, there has been a rapid increase in the use and the commercial availability of expandable cages for vertebral body replacement in the thoracolumbar spine. Although all 3 expandable cages, evaluated in this study, are approved for clinical use in Europe, little information is available concerning the biomechanical properties of these implants., Material and Methods: Thirty-two human thoracolumbar spines (T11 to L3) were tested in flexion, extension, axial rotation, and lateral bending with a nondestructive loading technique using an unconstrained testing apparatus. Three-dimensional displacement was measured using an optical measurement system. First, all motion segments were tested intact. After complete corporectomy of L1, cages were implanted according to producer's information. The following implants (n = 8/group) were tested: 1) meshed titanium cage (nonexpandable cage, DePuy AcroMed); 2) X-tenz (expandable cage, DePuy AcroMed); 3) Synex (expandable Cage; Synthes); and 4) VBR (expandable cage, Ulrich). Finally, posterior stabilization using the Universal Spine System (Synthes), posterior-anterior stabilization using the Universal Spine System (Synthes), and anterior plating (Locking Compression Plate, Synthes) was applied to each test specimen. The mean apparent stiffness values, range of motion, and neutral and elastic zone were calculated from the corresponding load-displacement curves., Results: No significant differences could be determined between the in vitro biomechanical properties of expandable and nonexpandable cages. In comparison to the intact motion segment, isolated anterior stabilization using cages and anterior plating significantly decreased stiffness and increased range of motion in all directions. In contrast, additional posterior stabilization significantly increased stiffness and decreased range of motion in all directions compared to the intact motion segment. The combined anterior-posterior stabilization demonstrated greatest stiffness results., Conclusion: Biomechanical results indicate that design variations of expandable cages for vertebral body replacement are of little importance. Additionally, no significant difference could be determined between the biomechanical properties of expandable and nonexpandable cages. After corporectomy, isolated implantation of expandable cages plus anterior plating was not able to restore normal stability of the motion segment. Therefore, isolated anterior stabilization using cages plus Locking Compression Plate should not be used for vertebral body replacement in the thoracolumbar spine.

Purpose of Review: To review current developments in the management of patients with testicular cancer, with special emphasis on risk factors for the primary tumour and treatment options for clinical stage I testicular germ cell tumours., Recent Findings: The management of patients with testicular cancer has substantially improved over the past 25 years. Current concepts for treating localized and regional disease have been influenced by effective systematic chemotherapy. At present, cure rates approach nearly 100% for low-stage disease and more than 80% for advanced disease., Summary: Retroperitoneal lymph node dissection is still favoured as the therapy of choice for clinical stage I non-seminomatous germ cell tumours in many centres, but as risk factors for the primary tumour have become better understood, surveillance and risk-adapted therapy, including surveillance for low-risk patients and adjuvant chemotherapy for the high-risk group, is now being considered a therapeutic option particularly in European centres. Adjuvant radiotherapy is still the gold standard for the treatment of patients with clinical stage I seminoma, but the relapse rate of 19% and a 5-year overall survival of 97.7% make surveillance a possible therapeutic option. The results of phase II and III trials should soon provide additional information on carboplatin for single-agent adjuvant chemotherapy.

Objective: Brain abscesses are life-threatening and sometimes difficult to detect. A brain abscess after placement, manipulation of a bone anchored hearing aid, or a periauricular implant for fixation of an ear prosthesis has never been reported in the literature., Patient: A 42-year-old man suffered from a right-sided temporodorsal brain abscess after change of a bone anchored hearing aid abutment. The fixture itself had been inserted 8 years before without any complications in the peri- or postoperative period. A CT-guided puncture of the abscess could be performed via the screw-hole in the temporal bone after removal of the fixture, and the patient was treated with antibiotics., Results: The outcome of the procedure was good without neurologic deficits for the patient., Conclusion: The insertion of periauricular screw implants bears the risk of meningeal lesions as well as a small risk of purulent intracranial and intracerebral complications perioperatively or in the context of later manipulations. Minimally invasive therapy of such brain abscesses can be performed by removal of the foreign body, CT-guided puncture, and antibiotic medication.

Cardiac surgery with cardiopulmonary bypass (CPB) results in transient cerebral swelling in most patients. Cognitive decline occurs in 24-57% of patients and 2-5% experience stroke. Serum levels of S-100B, a potential marker of increased blood-brain barrier permeability, increase during and early after surgery. The authors studied the effects of the novel Na /H exchange inhibitor cariporide (HOE642) on postoperative serum levels of S-100B and neuron-specific enolase (NSE) in 53 patients at high risk undergoing coronary artery bypass grafting. Patients were randomly assigned to one of four groups: I, placebo; II, 20 mg cariporide; III, 80 mg cariporide; IV, 120 mg cariporide). In addition, the leukocyte activation marker myeloperoxidase (MPO) and malondialdehyde (MDA), a marker for lipid peroxidation, were evaluated by enzyme-linked immunoassay. Postoperatively, five patients experienced transient ischemic attack or stroke. S-100B levels increased from 0.43 microg/l +/- 0.33 before operation to 2.27 microg/l +/- 0.69 1 hour after surgery in the placebo group. Preoperative S-100B levels in the HOE642 groups did not differ from the placebo group whereas, 1 hour after surgery, levels were significantly lower in groups II, III, and IV (1.63 microg/l +/- 0.2, 1.27 microg/l +/- 0.27, and 0.90 microg/l +/- 0.21, respectively). NSE, MPO, and MDA serum levels did not differ among groups. These findings may stimulate larger clinical studies to examine the effects of HOE642 on cerebral swelling and neurologic/cognitive outcome of cardiac surgery with CPB.

Background: The driving pressure gradient for cerebral perfusion is the difference between mean arterial pressure (MAP) and critical closing pressure (CCP = zero flow pressure). Therefore, determination of the difference between MAP and CCP should provide an appropriate monitoring of the effective cerebral perfusion pressure (CPP(eff)). Based on this concept, the authors compared conventional measurements of cerebral perfusion pressure by MAP and intracranial pressure (CPP(ICP)) with CPP(eff)., Methods: Simultaneous synchronized recordings of pressure waveforms of the radial artery and blood flow velocities of the middle cerebral artery were performed in 70 head trauma patients. CCP was calculated from pressure-flow velocity plots by linear extrapolation to zero flow., Results: Intracranial pressure measured by intraventricular probes and CCP ranged from 3 to 71 and 4 to 70 mmHg, respectively. Linear correlation between ICP and CCP was r = 0.91. CPP(ICP) was 77 +/- 20 mmHg and did not differ from CPP(eff); linear correlation was r = 0.92. However, limits of agreement were only +/- 16.2 mmHg. Therefore, in 51.4% of the patients, CPP(ICP) overestimated CPP(eff) by 19.8 mmHg at most., Conclusion: Assuming that CPP(eff) (MAP - CCP) takes into account more determinants of cerebral downstream pressure, in individual cases, the actual gold standard of CPP determination (MAP - ICP) might overestimate the CPP(eff) of therapeutic significance.

Study Design: The quantitative anatomic, radiographic, computerized tomographic, and biomechanical data of sheep and human cervical spines were evaluated., Objectives: To compare the anatomic, radiographic, computerized tomographic, and biomechanical data of human and sheep cervical spines to determine whether the sheep spine is a suitable model for human spine research., Summary of Background Data: Sheep spines have been used in several in vivo and in vitro experiments. Quantitative data of the normal sheep cervical spine are lacking, yet these data are crucial to discussion about the results of such animal studies., Methods: In this study, 20 fresh adult female Merino sheep cervical spines and 20 fresh human cadaver cervical spines were evaluated anatomically, radiographically, computerized tomographically, and biomechanically. Three linear and two angular parameters were evaluated on four digital radiographic views: anteroposterior, right lateral in neutral position, flexion, and extension. Quantitative computed tomography scans at the center of each vertebral body and 3 mm below both endplates were analyzed for bone mineral density measurements. Biomechanical testing was performed in flexion, extension, axial rotation, and lateral bending by a nondestructive stiffness method using a nonconstrained testing apparatus. Range of motion and stiffness of each motion segment were calculated. Additionally, 10 linear anatomic parameters of each vertebra were measured using a digital ruler., Results: Anterior and mean disc space height in the sheep cervical spine increased constantly from C2-C3 to C6-C7, whereas middle disc space height decreased and posterior disc space height remained unchanged. Anterior and mean disc space height were significantly higher in sheep. In both sheep and human cervical spines, intervertebral angles were not significantly different. Standard deviations of bone mineral density in the human cervical spine were fourfold higher than in the sheep cervical spine, yet no significant differences were found in bone mineral density values between the two species. Range of motion differed significantly between the two species except in flexion-extension of C3-C4, C5-C6, axial rotation of C2-C3, and lateral bending of C2-C3, C3-C4, and C4-C5. Stiffness also was significantly different except in flexion-extension of C2-C3, C4-C5, C5-C6, and lateral bending of C2-C3, C3-C4, and C4-C5. Anatomic evaluation showed no difference in upper endplate parameters for C4 and C5., Conclusions: Although several differences were found between human and sheep cervical spines, the small intergroup standard deviations and the good comparability with the human spine encourage the use of the sheep cervical spine as a model for cervical spine research. On the basis of the quantitative data obtained in this study, the sheep motion segment C3-C4 seemed to be the most reliable model for the corresponding human motion segment.

Background: Cyclosporine A (CsA) and tacrolimus prevent proliferation but not transendothelial migration of alloreactive lymphocytes into donor organs. As a result, serious adverse effects, such as nephrotoxicity and neurotoxicity, have been observed under CsA/tacrolimus therapy. The incorporation of new drugs with infiltration blocking properties might enhance the efficacy of the current immunosuppressive protocol, allowing lower CsA/tacrolimus dosage. Because Ca2+ plays a critical role in cell-cell interaction, the Ca2+-channel blocker verapamil might be a good cany. didate for supporting CsA/tacrolimus-based therapy., Methods: A T-cell endothelial cell coculture model or immobilized immunoglobulin G globulin chimeras were employed to investigate how S- and R- verapamil interfere with the lymphocytic infiltration process. The expression and arrangement of membranous adhesion receptors and cytoskeletal F-actin filaments were analyzed by fluorometric method in the presence of. verapamil., Results: Both verapamil enantiomers strongly inhibited lymphocyte infiltration. CD4+ and CD8+ T-cells were influenced to a similar extent with regard to horizontal locomotion (CD4+=CD8+), but to a different extent with regard to adhesion and penetration (CD4+ > CD8+). Moreover, penetration was blocked to a higher extent than was adhesion. ID50-values were 31 microM (CD4+-adhesion) and 11 microM (CD4+-penetration). Verapamil reduced P-selectin expression on endothelial cells and effectively down-regulated binding of T-cells to immobilized P-selectin immunoglobulin G globulins (ID50=4.4 microM; CD4+). A verapamil-induced reduction of intracellular F-actin in T-lymphocytes was proven to be mainly responsible for diminished cell locomotion., Conclusions: The prevention of CD4+ T-cell penetration by verapamil might argue for its use as an adjunct to CsA/tacrolimus-based immunosuppressive therapy.

Background: Currently, quantitative measurement of global cerebral blood flow (CBF) at bedside is not widely performed. The aim of the present study was to evaluate a newly developed method for bedside measurement of CBF based on thermodilution in a clinical setting., Methods: The investigation was performed in 14 anesthetized patients before coronary bypass surgery. CBF was altered by hypocapnia, normocapnia, and hypercapnia. CBF was measured simultaneously by the Kety-Schmidt inert-gas technique with argon and a newly developed transcerebral double-indicator dilution technique (TCID). For TCID, bolus injections of ice-cold indocyanine green were performed via a central venous line, and the resulting thermo-dye dilution curves were recorded simultaneously in the aorta and the jugular bulb using combined fiberoptic thermistor catheters. CBF was calculated from the mean transit times of the indicators through the brain., Results: Both methods of measurement of CBF indicate a decrease during hypocapnia and an increase during hypercapnia, whereas cerebral metabolic rate remained unchanged. Bias between CBF(TCID) and CBFargon was -7.1+/-2.2 (SEM) ml x min(-1) x 100 g(-1); precision (+/- 2 x SD of differences) between methods was 26.6 ml x min(-1) x 100 g(-1)., Conclusions: In the clinical setting, TCID was feasible and less time-consuming than alternative methods. The authors conclude that TCID is an alternative method to measure global CBF at bedside and offers a new opportunity to monitor cerebral perfusion of patients.

Objective: To test the practicability of a new double indicator dilution method for bedside monitoring of cerebral blood flow (CBF) and to assess the clinical value of CBF monitoring as a prognostic tool for outcome and in therapy of elevated intracranial pressure (ICP) in patients with acute hemispheric stroke., Design: Prospective study. Clinical evaluation of a new method., Setting: Neurological intensive care unit of a university hospital., Patients: Ten patients with acute complete middle cerebral artery territory- or hemispheric infarctions., Interventions: Two combined fiberoptic thermistor catheters were placed in the right jugular bulb and in the thoracic aorta. Central venous injections of ice-cold indocyanine green dye were performed. CBF was estimated by calculating the mean transit times of the cold bolus and dye., Measurements and Main Results: A total of 104 reproducible CBF measurements were obtained. No complications associated with the method were observed. Twelve pairs of measurements were performed within 30 mins with unchanged clinical conditions. The standard deviation of repeated measurements was 2.7 mL/100 g/min; the interrater reliability was between 0.95 and 0.99. The median CBF in patients who died (n = 4) was lower (27 mL/100g/min) than in those who survived (n = 6) (45 mL/100g/ min). Patients who died more frequently had low CBF values of <30 mL/100g/min (22 of 38; 58%) than patients who survived (10 of 54; 19%). A total of 37 CBF measurements were done during ICP elevation of >20 mm Hg. In patients who survived, ICP elevations were only associated with low CBF values in 5 of 26 events; whereas in patients who died, ICP elevations were associated with low CBF values in 8 of 11 events., Conclusions: The new double indicator dilution technique may be suitable for serial bedside CBF measurement. It is easy to perform and can be rapidly repeated in the ICU environment. Validation of the method by comparison with standard methods is needed. The preliminary data indicate that bedside monitoring of CBF may give prognostic information for outcome and may guide therapy of elevated ICP in patients with malignant hemispheric infarction.

Background: Cytomegalovirus (CMV) infection is associated with acute and chronic allograft rejection. We have recently shown that rat CMV increases portal inflammation and bile duct destruction in a model of rat liver allograft rejection. Desferrioxamine (DFO), an iron chelator and antioxidant, has recently been demonstrated to have antiviral as well as immunomodulatory effects in vitro. We therefore investigated whether DFO inhibits (a) CMV infection and (b) graft destruction in our rat model., Method: One day after liver transplantation, PVG (RT1c) into BN(RT1n), the rats were infected with rat CMV (RCMV, Maastricht strain; 10(5) plaque-forming units i.p.). The effects of 100 mg/kg body weight and 200 mg/kg body weight DFO were examined., Results: In the untreated group, the grafts were uniformly RCMV culture-positive. In the group receiving 200 mg/kg DFO, RCMV replication was effectively inhibited. Inflammatory response in the graft, and especially the number of macrophages, was significantly reduced by DFO. Portal inflammation and bile duct destruction were also significantly reduced. In the untreated group, the bile duct epithelial cells were found to be strongly positive for tumor necrosis factor-alpha and this expression was clearly decreased by DFO. In addition, DFO significantly inhibited vascular cell adhesion molecule-1 expression on sinusoidal endothelial cells., Conclusions: Our in vivo transplant study strongly supports the inhibitory effects of metal chelators on CMV infection and their possible usefulness in the treatment of CMV-induced pathogenic changes.

A 30-year-old man was referred to us with an extreme frontal and frontobasal defect from a motorbike accident 12 years before. Multiple attempts at frontal and frontobasal revision and reconstruction had been performed over the years, with several episodes of meningitis. Reconstruction was planned in two steps. First, a revision of the anterior skull base with mobilization of meningeal adhesions and duraplasty, removal of infected masses of polymethylmethacrylate out of the upper ethmoid sinuses, and coverage with a deepithelialized latissimus dorsi free flap were performed. In the second step 3 months later, aesthetic forehead reconstruction was achieved with a pre-fabricated individual titanium implant. The predictable result of this two-step reconstruction was very pleasing. Safe separation of the cranial cavity from the upper airways was essential, requiring free tissue transfer in this case, and is a prerequisite for any alloplastic forehead reconstruction. Timing of the two-step procedure, including the CT data acquisition; handling of soft tissues, bone, and foreign material; and construction details of the implant demonstrate the necessary complex management of this, the most difficult case of the 88 applications of the new computer aided design and manufacturing technique thus far. Even the most elaborate computer aided preparation cannot be successful without consideration of established surgical principles.

Unlabelled: In this study, we investigated the effect of sevoflurane on cerebral blood flow (CBF) autoregulation in rats. Twenty-four male Sprague-Dawley rats were randomly assigned to receive one of the following anesthetic treatments. In Group 1 (n = 8, control) anesthesia was maintained using fentanyl (25 microg x kg(-1) x h(-1)) and N2O/O2 (fraction of inspired oxygen 0.33). In Group 2 (n = 8) and Group 3 (n = 8), anesthesia was maintained using 2% sevoflurane (1 minimum alveolar anesthetic concentration [MAC]) and 2 MAC sevoflurane (4 vol%) in O2/air (fraction of inspired oxygen 0.33), respectively. Cortical CBF autoregulation was measured during graded hemorrhage within the mean arterial pressure (MAP) range of 100-30 mm Hg using laser Doppler flowmetry. CBF was constant with fentanyl/ N2O (Group 1) and 1 MAC sevoflurane (Group 2) within the MAP range of 100-40 mm Hg. In Group 3 (2 MAC sevoflurane), CBF decreased as a linear function of hemorrhagic hypotension. These results indicate that CBF autoregulation was intact during 1 MAC sevoflurane. In contrast, CBF autoregulation was impaired with 2 MAC sevoflurane. This is probably related to a reduction of baseline cerebrovascular tone with higher concentrations of sevoflurane, which results in a decreased capacity of autoregulatory cerebrovascular dilation during hemorrhage., Implications: The purpose of the present study was to investigate the effect of sevoflurane on cerebral blood flow autoregulation in rats. Cerebral blood flow autoregulation was intact with 1 minimum alveolar anesthetic concentration sevoflurane but was impaired with 2 minimum alveolar anesthetic concentration sevoflurane.

In this study, we investigated the effects of the intracellular metal chelator desferrioxamine (DFO) and the extracellular metal chelator diethylenetriamine penta-acetic acid (DTPA), which were previously shown to have strong anticytomegalovirus potencies, on their ability to elicit immunomodulatory effects in vitro[fcn,3]. The results showed that nontoxic and in vivo attainable concentrations of both DFO and DTPA inhibited mitogen- and allogen-induced proliferation of peripheral blood lymphocytes. The immunomodulatory effects of DFO/DTPA seem to be due to the impaired expression of interleukin-2 receptor and the reduced secretion of interleukin-2. However, metal chelators were more effective than cyclosporine or tacrolimus (FK506) in our in vitro experiments. Moreover, cytotoxicity mediated by lymphokine-activated killer cells and natural killer cells and the expression of HLA and adhesion molecules on cytokine-stimulated endothelial cells were differentially impaired by DFO/DTPA. These results warrant further study of the immunological effects of metal chelators in vivo.

Valproic acid (VPA) is a simple branched-chain fatty acid that has anticonvulsant activity and is widely used in the treatment of epilepsy. VPA was found to effect growth and differentiation of human neuroblastoma (NB) cells in vitro at concentrations that have been achieved in humans with no significant adverse effects. Treatment of UKF-NB-2 and UKF-NB-3 NB cell lines with VPA at concentrations ranging from 0.5 to 2 mM resulted in neuronal morphological differentiation characterized by extension of cellular processes without significant effects on cell viability. Ultrastructural features of VPA-treated cells were consistent with the neuronal type of differentiation. VPA treatment of NB cells was associated with decreased expression of N-myc oncoprotein and increased expression of neural cell adhesion molecule in their membrane. Treatment of NB cells with 0.5 mM VPA increased their sensitivity to lymphokine-activated killer lysis. The results indicate that VPA, at non-toxic pharmacological concentrations, arrests the growth, induces differentiation and increases immunogenicity of NB cells through non-toxic mechanisms.

Transplantation-related pathogenic factors such as ischemia or allograft-directed inflammation are associated with oxidative changes that might lead to cellular oxidative stress. The aim of this study was to investigate the impact of oxidative stress on: (1) CMV replication in cultured human endothelial cells and (2) the stimulation of endothelial cells by proinfiammatory cytokines. Both pathomechanisms are known to contribute to graft rejection crises in vivo. Oxidative stress was induced in endothelial cell cultures with 10-200 microM buthionine sulfoximine. Western blotting showed a significant increase in the production of CMV-specific immediate early and late proteins in buthionine sulfoximine-treated cultures. Immunocytochemical staining suggested that this effect was caused by increased numbers of CMV antigen expressing cells (66% immediate early; 78%, late). Quantitative polymerase chain reaction for CMV-specific DNA and virus titration revealed that enhanced viral replication levels correlated with increased virion production. As a measure for the endothelial cell activation status, the surface expression of HLA-ABC and HLA-DR and adhesion molecules (ICAM-1, ELAM-1, VCAM-1) was quantified by fluorometric methods. Whereas oxidative stress alone did not modulate any surface molecule expression, the IFN-gamma-mediated expression of HLA-ABC and HLA-DR and the IL-1-mediated expression of ICAM-1, but not of ELAM-1 and VCAM-1 (IL-1 + TNF-alpha), was amplified. Interestingly, the amplification of HLA molecule expression was even higher in CMV-infected endothelial cells. This study provides evidence that oxidative stress contributes to the regulation of CMV replication, virus shedding, and the activation of endothelial cells by proinflammatory cytokines as it is observed in transplant recipients.

Expression of adhesion molecules and human leukocyte antigens on the surface of hepatocytes (HC) may play an important role in the immune reaction in different types of infectious and noninfectious hepatitis, liver graft rejection, and autoimmune liver diseases. The aim of this study was to evaluate the influence of the proinflammatory cytokines IFN-alpha, IFN-gamma, and IL-1 alpha on the expression of intercellular adhesion molecule-1 (ICAM-1) and HLA-A, -B, -C, and -DR on highly purified primary human HC in cell culture. Expression was assessed by semiquantitative measurement of HC in cell culture by means of computer-aided fluorometry after immunofluorescent labeling. Avidin-biotin-immunoperoxidase staining was applied on parallel cultures to evaluate cell purity (> 99%) and to confirm the results obtained by fluorometry. ICAM-1 was expressed constitutively on untreated HC in vitro. Stimulation of HC with IFN-gamma and IL-1 alpha for 24 hr resulted in an increase of ICAM-1 expression. Cultured HC were moderately HLA-A, -B, and -C positive, but HLA-DR negative. Stimulation of HC with 500 U/ml IFN-gamma for 72 hr resulted in an increase of HLA-A, -B, -C, and -DR expression, whereas stimulation with 10 U/ml IL-1 alpha for 72 hr had no influence. By using 5000 U/ml IFN-alpha for 72 hr, we achieved an increase of HLA-A, -B, and -C expression; effects on the other tested antigens were not significant. In contrast to endothelial cells and transformed human hepatocytic cell lines, ICAM-1 on HC was changed more intensively by IFN-gamma than by IL-1 alpha. Furthermore, the results reveal differences in HLA and ICAM-1 expression between HC in vivo and in vitro.

Background: Management of intravascular volume is crucial in patients after cardiopulmonary bypass as myocardial dysfunction is common. The purpose of this study was to validate a novel bedside technique for real-time assessment of intravascular volumes., Methods: Eleven patients undergoing cardiopulmonary bypass were studied. In addition to standard monitors, a fiberoptic thermistor catheter was placed in the descending aorta and central venous injections of 10 ml ice-cold indocyanine green dye were performed. Total blood volume was measured by a standard in vitro technique. Circulating and central blood volume were calculated by using cardiac output, mean transit times, and a newly developed recursive convolution algorithm that models recirculation. Measurements were performed after induction of anesthesia and at 1, 6, and 24 h after surgery., Results: A two-compartment model of the circulation was required for adequate fit of the data. We found a significant correlation between total and circulating blood volumes (r = 0.87). One hour after surgery, central blood volume was decreased by 10% (P < 0.05). At 6 and 24 h after surgery, circulating blood volumes were significantly increased by 29% and 20%, respectively (P < 0.01), although central blood volume was similar to control values. Before surgery stroke volume index correlated with circulating blood volume (r = 0.87) but not with pulmonary capillary wedge and central venous pressures., Conclusions: This study shows that bedside determinations of intravascular blood volumes are feasible and that these measurements are more indicative of intravascular volume status than are either pulmonary capillary wedge or central venous pressures in the post-cardiopulmonary bypass period. Our data also demonstrate that despite a normal central blood volume both circulating and total blood volume are significantly increased in the immediate post-cardiopulmonary bypass period.

The role of hypothermic storage of rat kidneys on lipid peroxidation compared to its effect on mitochondrial respiratory parameters has been investigated. Rat kidneys were flushed with cold solutions of isotonic sodium chloride; Euro-Collins'; preservation solution containing histidine buffer, tryptophane, and alpha-ketoglutarate (HTK); or hypertonic citrate and then stored for 20 hr at 4 degrees C. After storage, the endogenous contents of malondialdehyde as well as the chemically (by Fe2+/ascorbic acid) and enzymatically (by Fe3+/ADP/NADPH) induced generation of malondialdehyde were measured in cortical homogenates and partly in mitochondria and microsomes by the thiobarbituric-acid reaction. Compared to the values measured in fresh, unstored kidneys, the levels of malondialdehyde were significantly higher in kidneys preserved in solutions of isotonic sodium chloride or HTK. This stimulating effect of the HTK solution on the generation of lipid peroxidation products could also be established when homogenate was incubated with this solution. Euro-Collins' and hypertonic citrate solution did not change the endogenous contents of malondialdehyde in kidneys during hypothermic storage. Both the chemically and enzymatically induced lipid peroxidation increased after hypothermic storage of kidneys in all solutions investigated. No direct relationship between the contents of malondialdehyde and respiratory mitochondrial parameters was detectable. The results demonstrate that the extent of lipid peroxidation does not correlate with preservation effectiveness.