Pigment-protein complexes are organized into stable microdomains in cyanobacterial thylakoids.

Thylakoids are the place of the light-photosynthetic reactions. To gain maximal efficiency, these reactions are conditional to proper pigment-pigment and protein-protein interactions. In higher plants thylakoids, the interactions lead to a lateral asymmetry in localization of protein complexes (i.e. granal/stromal thylakoids) that have been defined as a domain-like structures characteristic by different biochemical composition and function (Albertsson P-Å. 2001,Trends Plant Science 6: 349-354). We explored this complex organization of thylakoid pigment-proteins at single cell level in the cyanobacterium Synechocystis sp. PCC 6803. Our 3D confocal images captured heterogeneous distribution of all main photosynthetic pigment-protein complexes (PPCs), Photosystem I (fluorescently tagged by YFP), Photosystem II and Phycobilisomes. The acquired images depicted cyanobacterial thylakoid membrane as a stable, mosaic-like structure formed by microdomains (MDs). These microcompartments are of sub-micrometer in sizes (~0.5-1.5 µm), typical by particular PPCs ratios and importantly without full segregation of observed complexes. The most prevailing MD is represented by MD with high Photosystem I content which allows also partial separation of Photosystems like in higher plants thylakoids. We assume that MDs stability (in minutes) provides optimal conditions for efficient excitation/electron transfer. The cyanobacterial MDs thus define thylakoid membrane organization as a system controlled by co-localization of three main PPCs leading to formation of thylakoid membrane mosaic. This organization might represent evolutional and functional precursor for the granal/stromal spatial heterogeneity in photosystems that is typical for higher plant thylakoids.

Bistable self-assembly in homogeneous colloidal systems for flexible modular architectures.

This paper presents a homogeneous system of magnetic colloidal particles that self-assembles via two structural patterns of different symmetry. Based on a qualitative comparison between a real magnetic particles system, analytical calculations and molecular dynamics simulations, it is shown that bistability can be achieved by a proper tailoring of an anisotropic magnetization distribution inside the particles. The presented bistability opens new possibilities to form two-dimensionally extended and flexible structures where the connectivity between the particles can be changed in vivo.

Mapping microscopic order in plant and mammalian cells and tissues: novel differential polarization attachment for new generation confocal microscopes (DP-LSM).

Elucidation of the molecular architecture of complex, highly organized molecular macro-assemblies is an important, basic task for biology. Differential polarization (DP) measurements, such as linear (LD) and circular dichroism (CD) or the anisotropy of the fluorescence emission (r), which can be carried out in a dichrograph or spectrofluorimeter, respectively, carry unique, spatially averaged information about the molecular organization of the sample. For inhomogeneous samples-e.g. cells and tissues-measurements on macroscopic scale are not satisfactory, and in some cases not feasible, thus microscopic techniques must be applied. The microscopic DP-imaging technique, when based on confocal laser scanning microscope (LSM), allows the pixel by pixel mapping of anisotropy of a sample in 2D and 3D. The first DP-LSM configuration, which, in fluorescence mode, allowed confocal imaging of different DP quantities in real-time, without interfering with the 'conventional' imaging, was built on a Zeiss LSM410. It was demonstrated to be capable of determining non-confocally the linear birefringence (LB) or LD of a sample and, confocally, its FDLD (fluorescence detected LD), the degree of polarization (P) and the anisotropy of the fluorescence emission (r), following polarized and non-polarized excitation, respectively (Steinbach et al 2009 Acta Histochem.111 316-25). This DP-LSM configuration, however, cannot simply be adopted to new generation microscopes with considerably more compact structures. As shown here, for an Olympus FV500, we designed an easy-to-install DP attachment to determine LB, LD, FDLD and r, in new-generation confocal microscopes, which, in principle, can be complemented with a P-imaging unit, but specifically to the brand and type of LSM.

Comprehensive assessment of HIV target cells in the distal human gut suggests increasing HIV susceptibility toward the anus.

BACKGROUND: Prevention of rectal HIV transmission is a high-priority goal for vaccines and topical microbicides because a large fraction of HIV transmissions occurs rectally. Yet, little is known about the specific target-cell milieu in the human rectum other than inferences made from the colon. METHODS: We conducted a comprehensive comparative in situ fluorescence study of HIV target cells (CCR5-expressing T cells, macrophages, and putative dendritic cells) at 4 and 30 cm proximal of the anal canal in 29 healthy individuals, using computerized analysis of digitized combination stains. RESULTS: Most strikingly, we find that more than 3 times as many CD68 macrophages express the HIV coreceptor CCR5 in the rectum than in the colon (P = 0.0001), and as such rectal macrophages seem biologically closer to the HIV-susceptible CCR5 phenotype in the vagina than the mostly HIV-resistant CCR5 phenotype in the colon. Putative CD209 dendritic cells are generally enriched in the colon compared with the rectum (P = 0.0004), though their CCR5 expression levels are similar in both compartments. CD3 T-cell densities and CCR5 expression levels are comparable in the colon and rectum. CONCLUSIONS: Our study establishes the target-cell environment for HIV infection in the human distal gut and demonstrates in general terms that the colon and rectum are immunologically distinct anatomical compartments. Greater expression of CCR5 on rectal macrophages suggests that the most distal sections of the gut may be especially vulnerable to HIV infection. Our findings also emphasize that caution should be exercised when extrapolating data obtained from colon tissues to the rectum.

Do insulin-like growth factor associated proteins qualify as a tumor marker? Results of a prospective study in 163 cancer patients.

OBJECTIVE: Insulin-like growth factor (IGF)-1, -2 and Insulin like growth factor binding proteins (IGFBP) are involved in the proliferation and differentiation of cells. It has never been evaluated, if the IGF-system can serve as a tumor marker in neoplasms. METHODS: In our prospective study 163 patients with colorectal cancer (22), prostate cancer (21), head and neck tumors (17), lymphomas (20), lung cancer (34) and other entities (49) were analysed for their IGF and IGFBP serum levels at the beginning and the end of radiotherapy and compared to 13 healthy people. Subgroups of patients with local tumor disease versus metastatic disease, primary and recurrent therapy and curative versus palliative therapy were compared. RESULTS: The serum levels of IGF-2 were significantly elevated in patients with prostate and colorectal cancer. However, sensitivity and specificity were only 70%. IGFBP-2 serum levels were elevated in patients with head and neck tumors. Again sensitivity and specificity were only 73%. A difference between local disease and metastatic disease could not be found. A difference between IGF serum levels before and after radiotherapy could not be detected. CONCLUSION: The IGF-system cannot serve as a new tumor marker. The detected differences are very small, sensitivity and specificity are too low. IGF measurement is not useful for the evaluation of the success of radiotherapy in malignancies.

[Myeloablative radioimmunotherapy with 188Re-CD66mAb before stem cell transplantation. No increase of proinflammatory cytokine levels of TNF-alpha]. / Myeloablative Radioimmuntherapie mit 188Re-CD66mAb vor Stammzelltransplantation: Kein Anstieg proinflammatorischer Zytokinspiegel von TNF-alpha.

AIM: Tumour necrosis factor-alpha (TNF-alpha) serum levels may increase due to intensive conditioning regimes with high-dose-chemotherapy and total body irradiation (TBI) before stem cell transplantation. This increases the risk for developing acute graft versus host disease (aGvHD) after stem cell transplantation. In this prospective study we investigated the influence of radioimmunotherapy with 188Re-CD-66-mAb on changes on TNF-alpha serum levels. PATIENTS, METHODS: In 18 patients we measured TNF-alpha before and up to 96 hours after radioimmunotherapy, in 2 patients in addition following TBI, in 9 patients also following chemotherapy. For measuring TNF-alpha we used an automated immunochemiluminescence assay (Immulite 1000 DPC Biermann, Bad Nauheim). The mean follow up period to record incidence of aGVHD was 100 days after stem cell transplantation. RESULTS: Compared to the basal levels before, the levels of TNF-alpha after conditioning with 188Re-CD-66-mAb did not increase significantly and remained in the physiological range. In contrast, these initial physiological cytokine levels increased and became pathological following 48 h after total body irradiation (13.2+/-6.6 pg/ml) and chemotherapy (10.8+/-15.7 pg/ml). In our study we found a low incidence of aGvHD (22.2%, n=4/18). CONCLUSION: These results demonstrate that additional conditioning therapy with 188Re-CD-66-mAb does not increase proinflammatory cytokine levels of TNF-alpha. This finding may indicate that additive radioimmunotherapy may not be a significant factor for increasing the rate of conditioning-associated aGvHD.

Validity of S-100 B in patients after brain radiation.

BACKGROUND: S-100B is a calcium binding acute phase protein and a potential biomarker for brain injury. In prior studies elevated plasma S-100B levels were detected in stroke and severe head trauma. The aim of this study was to evaluate whether S-100 B is elevated during cerebral radiotherapy and whether that is associated with adverse outcomes. MATERIAL AND METHODS: In this prospective pilot study, 45 patients (25 males, 20 females, median age 58 (17-81)) underwent cerebral radiation therapy because of a primary or metastaic cerebral malignancy. 39 patients were included in the evaluation. 6 patients died during the study period. S-100 plasma concentrations were measured with an electrochemiluminescence immunoassay on admission and weekly during radiation therapy for the duration of 6 weeks. In 10 healthy young volunteers (5 males, 5 females, median age 32 (28-36)) S-100 B plasma levels were measured weekly for 6 weeks as a negative control. Furthermore, in an active control 10 patients (4 males, 6 females, median age 68 (64-76)) with stroke (7 = major stroke, 3 = lacunar infarct) S- 100 B plasma levels were measured for 7 consecutive days after the event. RESULTS: During radiotherapy S-100 B plasma concentrations increased from median baseline values of 0.030 microg/l to 0.044 microg/l. For the time of radiation therapy most patients showed a mild increase, but absolute plasma values were still within the normal range. In the control group of healthy volunteers S-100 B remained unchanged. In stroke patients S-100 B increased to maximum values of 1.7 microg/l three days after the event. In the 3 patients with lacunar infarcts no increase of S-100 B levels could be detected. CONCLUSION: Brain irradiation leads to a mild increase of S-100 B plasma levels. However, the absolute rise was far weaker compared to that seen in major brain injuries.

In vivo results for interstitial laser application in thyroid gland.

OBJECTIVE: Aim of this study was to evaluate the potential of denaturation of hormone active tissue in the thyroid gland by laser induced interstitial thermotherapy (LITT) as a treatment of autonomous hyperthyroidism. MATERIALS AND METHODS: An interstitial thyroid laser application (Nd:YAG 1064 nm, 5W, 2 min) was performed in 5 pigs. During laser application, the laryngeal recurrent nerve was controlled electro-physiologically. Postoperatively, TSH, total T(3) (TT(3)) and free T(4) (FT(4)) were measured regularly. After a follow-up period of up to 6 weeks, pigs were sacrificed and the thyroid glands were evaluated histological. RESULTS: A malfunction of the nerve due to laser treatment was not detected. During the first postoperative week there was a decrease of both FT(4) and TSH whereas TT(3) showed an extreme decline of its plasma levels reaching nearly the detection limit. All values showed a recovery to their initial levels during an interval of 10 days and than increased to levels sometimes higher than baseline. The coagulation zones were demarcated clearly towards normal tissue with increasing fibrosis of the treated areas. CONCLUSION: Interstitial thyroid ablation using a Nd:YAG laser is a minimal invasive, safe and effective procedure. Further evaluation including long term follow-up in humans is needed to confirm these results.

Inflammatory peritoneal reaction after perforated appendicitis: continuous peritoneal lavage versus non lavage.

INTRODUCTION: Bacterial peritonitis is a severe medical condition associated with a natural mortality rate of 80-100%. Progress in surgical techniques, new developments in intensive care medicine and antibiotic therapy reduced this rate significantly. Aim of this study was to evaluate sepsis parameter in perforated appendicitis and different postoperative management. METHODS: In 50 consecutive patients with diffuse bacterial peritonitis and perforated appendicitis, laparotomy was performed. Subsequently, 25 patients were treated with adjuvant, continuous peritoneal lavage (CPL) using standard peritoneal dialysis (CAPD)-solution. The remaining 25 patients were peritoneally drained without postoperative irrigation (Non-CPL). In all patients endotoxin, tumor necrosis factor-alpha (TNF-alpha), interleukin (IL-6), C-reactive protein (CRP) and myeloid-related protein (MRP-8, MRP-14 and Heterocomplex) were determined. RESULTS: No difference in clinical outcome between CPL and Non-CPL could be established. An uncomplicated clinical outcome was associated with lower levels of inflammation markers. Furthermore, clinical data revealed that mortality depended on co-morbidity, and patient's age. SUMMARY: In perforated appendicitis a faster decrease of mediator release could not be achieved with either method. In addition, no difference could be established for the clinical parameters like hospitalization, duration of intensive care and morbidity.

Efficacy of neodymium:YAG laser therapy for gastric antral vascular ectasia (GAVE) following hematopoietic cell transplant.

We determined the incidence of severe bleeding from gastric antral vascular ectasia (GAVE) after myeloablative hematopoietic cell transplant and the outcomes after treatment with endoscopic neodymium:YAG laser photocoagulation. From 1992 to 2005, the incidence of severe bleeding from GAVE was 6/4491 (0.13%). All patients had received oral busulfan and four had sinusoidal obstruction syndrome. Gastrointestinal bleeding began a median of 53 days after transplant (range 15-2952). After GAVE was diagnosed by endoscopic and histologic findings, a median of three (range 2-7) sessions of laser therapy were required to control the bleeding with a median of 2737 J (range 1117-6160 J) per session. A median of 16 units (range 4-44) had been transfused prior to laser therapy and a median of four additional units (range 0-113) were transfused until bleeding was controlled. All patients were followed for at least 70 days after the last laser therapy session, with no further episodes of bleeding. Complications were mild and included abdominal pain and asymptomatic ulceration; however, one patient required gastrectomy due to gastric necrosis following transarterial embolizations. In summary, severe bleeding from GAVE is rare following hematopoietic cell transplant. Treatment with endoscopic therapy using the Nd:YAG laser is safe and effective.

Whole blood interleukin 8 and plasma interleukin 8 levels in newborn infants with suspected bacterial infection.

AIM: To evaluate a new micro-method technique for measurement of interleukin 8 in detergent-lysed whole blood (whole blood IL-8) applicable to capillary blood sampling as a test for bacterial infections in neonates. METHODS: Whole blood IL-8 was measured at the first suspicion of infection along with IL-8 determined in plasma (plasma IL-8), C-reactive protein and blood cultures in 154 consecutive newborn infants with clinical signs of bacterial infection. Only 20 microl of whole blood were required for the new assay. RESULTS: Blood culture-proven infections were diagnosed in six infants and clinical infection (defined as a combination of clinical and laboratory signs) in 20 infants. 1000 pg/ml was determined as the suitable threshold for whole blood IL-8 by ROC-curve analysis. At that threshold, whole blood IL-8 detected blood culture-proven infections with a sensitivity of 83% and a specificity of 67%. The areas under the ROC curves were similar for whole blood IL-8 and plasma IL-8. CONCLUSIONS: Compared with plasma IL-8, whole blood IL-8 offers the advantages that measurements of whole blood IL-8 require a smaller blood sample volume and are not altered by haemolysis. The diagnostic accuracy of whole blood IL-8 remains to be studied in more detail in the future.

IL-6 and PGE2 release by human osteoblasts on implant materials.

Regarding orthopaedic implant loosening it has been hypothesized that particle-activated macrophages release interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha). This in turn stimulates osteoblasts to release interleukin-6 (IL-6) and prostaglandin E(2) (PGE(2)). These mediators recruit and activate osteoclasts and may therefore lead to bone resorption and loss of implant fixation. In this study we compared the ability of different materials to induce the release of IL-6 and PGE(2) from primary isolated, human osteoblasts without preceding activation by macrophages. We tested stainless steel, cobalt-chromium alloy (CoCrMo), commercially pure titanium (cpTi), Ti-6Al-7Nb and Ti-6Al-4V processed in the same manner as corresponding clinical implants. After 12 and 24h the cells had actively secreted IL-6 and PGE(2). There were no clear differences among the implant materials or with the plastic control. The amount of factors the cells released in our study compare well with the findings of other authors who investigated osteoblasts on plastic. In comparison with the literature these amounts are lower than secretion levels of osteoblasts stimulated with implant particles, IL-1 or TNF-alpha. Moreover, other authors found that osteoclasts require higher concentrations of PGE(2) to become activated than the concentrations measured in our experiments. Therefore, the amount of PGE(2) released from the osteoblasts in our study is probably not sufficient to induce osteolytic activity. Because of contradictory statements in the literature it is unclear if the measured IL-6 concentrations promote osteolytic activity. Differences in material composition does not significantly influence the release of these factors if the materials have similar surface roughnesses.

Effects of various applications of lipopolysaccharides on blood parameters of pigs.

In five experiments, lipopolysaccharides (LPS) of Escherichia coli O26:B6 and O111:B4 were applied intravenously, intramuscularly, subcutaneously or intrabronchially in doses of 5000-15,000 U/kg body mass to a total of 47 weaner pigs and compared with the application of sodium chloride. Different parameters of blood cells were investigated, including cell numbers, in vivo interleukin secretion, radical formation, phagocytosis capacity and IL-6 as well as TNFalpha formation ex vivo. Non-specific effects and dependencies on the type of application and LPS dose are discussed.

Estimating the prevalence of Salmonella spp. in swine herds--influence of sensitivity and specificity of Salmonella detection.

Information about the proportion of truly Salmonella-free herds is required for an evaluation of the epidemiological situation, the development of control strategies and their implementation. Findings regarding the presence of salmonellas in faeces and intestinal lymph nodes as well as the presence of Salmonella antibodies in meat juice from slaughtered pigs were obtained in the context of a study conducted by a number of institutes. These data were used for an analysis of the validity of data on the prevalence of infected animals within herds and on the prevalence of infected herds. The proportion of batches or herds with exclusively negative individual findings was found to depend not only on the true proportion of truly Salmonella-free animals within herds but quite essentially also on the distribution of the proportion of infected animals within herds, the sensitivity of the methods of examination and sample sizes. When taking into account the existing dependencies, it was found that among the swine, the real numbers of Salmonella carriers were much higher than shown by bacteriological and serological examination. Regarding salmonellosis in swine, also a number of contaminated herds must be expected which is far higher than that shown by the number of herds with positive findings in at least one animal. Even a low contamination of all or almost all herds would result in the numbers of 'negative' batches observed, i.e. batches with exclusively negative individual findings. A rating of the salmonella exposure of herds as high, low, or very low is possible and may, and should be, used for measures of consumer protection, irrespective of the proportion of truly Salmonella-free herds.

Circulating procalcitonin and cleavage products in septicaemia compared with medullary thyroid carcinoma.

OBJECTIVE: Raised plasma levels of procalcitonin (proCT) represent an early marker for septicaemia. They are related to disease severity and inversely to outcome and response to treatment. ProCT is presumably synthesised in tIssues other than the thyroid C-cells which are the source of calcitonin (CT) in normal physiology. This study compares proCT and its cleavage products in the serum of patients with septicaemia with those in medullary thyroid carcinoma (MTC). METHODS: Immunoreactive proCT and its cleavage products were extracted from the serum of patients with septicaemia or MTC using octadecylsilyl silica columns and characterised by reversed phase HPLC and Western blot analysis. ProCT, CT(1-32) and the flanking peptides PAS-57 and PDN-21 were recognised with antibodies specific for the individual peptides. RESULTS: ProCT and a 10 kDa polypeptide were recognised with antibodies to PAS-57, CT(1-32) and PDN-21. An 8 kDa proCT fragment was detected with antibodies to CT and PDN-21. However, intact CT(1-32), PAS-57 and PDN-21, found in the serum of MTC patients, were undetectable. The results indicate partial cleavage of proCT in septicaemia different from that in MTC patients. CONCLUSIONS: ProCT and 10 and 8 kDa proCT fragments were recognised in the circulation of septic patients. They were different from the known proCT-processing products PAS-57, CT(1-32) and PDN-21 identified in the serum of normal subjects and of MTC patients. Distinct cleavage of proCT may contribute to the symptoms of septicaemia.

A randomised, double blind, placebo controlled study of celecoxib, a selective cyclooxygenase 2 inhibitor, on duodenal polyposis in familial adenomatous polyposis.

BACKGROUND: Non-selective cyclooxygenase (COX) inhibitors (non-steroidal anti-inflammatory drugs) inhibit large bowel carcinogenesis in patients with familial adenomatous polyposis (FAP). Their role in the duodenum of these patients is less certain. The disease modifying activity of specific COX-2 inhibitors has not been explored in humans. PATIENTS AND METHODS: This was a randomised, double blind, placebo controlled study of celecoxib (100 mg twice daily (n=34) or 400 mg twice daily (n=32)) versus placebo (n=17), given orally twice daily for six months to patients with FAP. Efficacy was assessed qualitatively by blinded review of shuffled endoscopy videotapes comparing the extent of duodenal polyposis at entry and at six months and quantitatively by measurement of the percentage change in duodenal area covered by discrete and plaque-like adenomas from photographs of high and low density polyposis. RESULTS: Shuffled and blinded video review showed a statistically significant effect of 400 mg twice daily celecoxib compared with placebo treatment (p=0.033) with all five independent observers scoring a beneficial effect. Overall, patients taking celecoxib 400 mg twice daily showed a 14.5% reduction in involved areas compared with a 1.4% for placebo (p=0.436). However, patients with clinically significant disease at baseline (greater than 5% covered by polyps) showed a 31% reduction in involved areas with celecoxib 400 mg twice daily compared with 8% on placebo (p=0.049). CONCLUSIONS: A panel of five endoscopists found a significant reduction in duodenal polyposis after six months of treatment with celecoxib 400 mg twice daily. COX-2 inhibition may help this otherwise untreatable condition.

Inflammatory response during abdominal and thyroid surgery: a prospective clinical trial on mediator release.

Several studies have been demonstrated that endotoxin is a potent stimulus of the acute inflammatory response following traumatic injury. Although numerous studies have indicated that the extent of surgical intervention correlates well with the inflammatory response, the potential role of endotoxin as a trigger under those conditions still remains unknown. Therefore, the aim of this study was to elucidate whether or not the up-regulated inflammatory mediators are paralleled by increased endotoxin plasma levels during and following surgery, and whether the extent of surgical intervention represents a crucial factor under those conditions. To study this, plasma was collected at various time points during and after surgery from 52 patients subjected to abdominal surgery (i.e., major surgery) and 25 patients subjected to thyroid surgery (i.e., minor surgery). Plasma was assessed for endotoxin, endotoxin neutralizing capacity (ENC), and inflammatory mediators (leucotriene-C4 [LTC4]-, 6-keto-prostaglandin-F-1-alpha [PGF]-, thromboxane-B2 [TxB2], interleukin-6 [IL-6], and C-reactive protein [CRP]). Furthermore, splanchnic blood circulation was measured by determination of the intraluminal pH of the stomach and sigma (pHi) by intraluminal tonometry. Mesenteric lymph nodes were also collected at the time point of organ mobilization in the major surgery group and were assessed for bacterial translocation. Among all parameters investigated, endotoxin showed the most rapid changes. A significant increase in plasma levels of endotoxin and a decrease of ENC were found in the major surgery groups following induction of anesthesia and in the minor surgery groups after skin incision. Moreover, the incidence of elevated endotoxin levels was significantly higher (89% with elevated endotoxin levels) than the incidence of bacterial translocation (35% with gram-negative bacteria) in mesenterial lymph nodes of the major surgery group. pHi decreased significantly in both groups after skin incision, but no difference was observed between the major and minor surgery groups. Plasma mediators of the arachidonic acid cascade (LTC4, PGF, and TxB2) were only elevated in individual patients during and following surgery in both groups. Conversely, the post-operative increase in the acute phase mediators was significantly different in the major and minor surgery groups. IL-6 plasma levels peaked higher and earlier after major surgery than after minor surgery and the delayed increase of CRP was significantly greater in the major surgery group. In conclusion, the results indicate that plasma levels of endotoxin significantly correlate with the severity of the surgical intervention and may play an important role in inducing mediators of the acute phase reaction under such conditions.

Lumbar spine disc height and curvature responses to an axial load generated by a compression device compatible with magnetic resonance imaging.

STUDY DESIGN: Axial load-dependent changes in the lumbar spine of supine healthy volunteers were examined using a compression device compatible with magnetic resonance imaging. OBJECTIVE: To test two hypotheses: Axial loading of 50% body weight from shoulder to feet in supine posture 1) simulates the upright lumbar spine alignment and 2) decreases disc height significantly. SUMMARY OF BACKGROUND DATA: Axial compression on the lumbar spine has significantly narrowed the lumbar dural sac in patients with sciatica, neurogenic claudication or both. METHODS: Using a device compatible with magnetic resonance imaging, the lumbar spine of eight young volunteers, ages 22 to 36 years, was axially compressed with a force equivalent to 50% of body weight, approximating the normal load on the lumbar spine in upright posture. Sagittal lumbar magnetic resonance imaging was performed to measure intervertebral angle and disc height before and during compression. RESULTS: Each intervertebral angle before and during compression was as follows: T12-L1 (-0.8 degrees +/- 2.5 degrees and -1.5 degrees +/- 2.6 degrees ), L1-L2 (0.7 degrees +/- 1.4 degrees and 3.3 degrees +/- 2.9 degrees ), L2-L3 (4.7 degrees +/- 3.5 degrees and 7.3 degrees +/- 6 degrees ), L3-L4 (7.9 degrees +/- 2.4 degrees and 11.1 degrees +/- 4.6 degrees ), L4-L5 (14.3 degrees +/- 3.3 degrees and 14.9 degrees +/- 1.7 degrees ), L5-S1 (25.8 degrees +/- 5.2 degrees and 20.8 degrees +/- 6 degrees ), and L1-S1 (53.4 degrees +/- 11.9 degrees and 57.3 degrees +/- 16.7 degrees ). Negative values reflect kyphosis, and positive values reflect lordosis. A significant difference between values before and during compression was obtained at L3-L4 and L5-S1. There was a significant decrease in disc height only at L4-L5 during compression. CONCLUSIONS: The axial force of 50% body weight in supine posture simulates the upright lumbar spine morphologically. No change in intervertebral angle occurred at L4-L5. However, disc height at L4-L5 decreased significantly during compression.

Endovascular stent-graft placement versus conventional open surgery in infrarenal aortic aneurysm: a prospective study on acute phase response and clinical outcome.

BACKGROUND: For the treatment of aortic aneurysm, stent-graft implantation is an alternative method to open surgery. There is no study comparing both methods with regard to endotoxaemia, the acute phase cascade, and clinical outcome. METHODS: In this prospective study, we enrolled 40 patients (34 males, 6 females; mean age 72.1+/-7.5 [58-92] years) with infrarenal abdominal aortic aneurysm who underwent aortic surgery. Comparable groups of patients were treated with open (n=20) or endovascular (n=20) stent-graft implantation. To characterize the inflammatory response, plasma levels of endotoxin, endotoxin-neutralizing capacity (ENC), interleukin-6 (IL-6), C-reactive protein (CRP), and white blood cell count were determined. In all patients, measurements were performed on admission, skin suture, 4 h and from the first to fifth postoperative day. As parameters for the clinical outcome, we assessed daily temperature, lung function, pain, duration of postoperative hospital stay, and morbidity. Wilcoxon rank test was used for statistical analysis. RESULTS: In both groups, a significant increase of endotoxin plasma levels and a decrease of ENC was found already after skin incision. IL-6 levels peaked 4 h postoperatively in both groups, whereas CRP rose at the first postoperative day, reaching a maximum at day 2. Conventionally operated patients had significantly higher plasma levels of endotoxin, IL-6, and CRP and lower ENC during and after surgery than patients with stent-graft implantation. Moreover, patients with endovascular stent grafting had significant less postoperative pain, less restriction of total vital capacity, a shorter hospital stay, and a lower morbidity. CONCLUSIONS: Endovascular stent grafting of infrarenal aortic aneurysm seems to be superior not only in terms of the inflammatory response but also in overall clinical outcome.

Interleukin-8: a valuable tool to restrict antibiotic therapy in newborn infants.

UNLABELLED: This study was conducted to evaluate the accuracy and kinetics of interleukin 8 (IL-8) as a test for early-onset bacterial infections (EOBI) in neonates and to examine whether IL-8 would allow "unnecessary" antibiotic therapy to be reduced. First, IL-8 was measured 378 times on admission, along with C-reactive protein (CRP), immature to total neutrophil ratio (IT ratio) and blood cultures, in full-term and preterm neonates with suspected EOBI. Combined culture-proven and clinical EOBI were detected on admission by the combination of IL-8 > or = 70 pg ml(-1) and/or CRP > 10 mg l(-1) with 92% sensitivity and 74% specificity. An increased IL-8 was found in 62% of the infected infants, while CRP was still normal. In a second study period, IL-8 was determined prospectively in 331 infants who presented clinical signs of EOBI or had a birth history of amniotic infection. Antibiotic therapy was restricted to those infants with suspected infection who also had an increased IL-8 and/or CRP (n = 158). Another 39 infants received antibiotics on the basis of clinical signs despite negative IL-8 and CRP. Of 150 non-infected infants in whom IT ratio, IL-8 and CRP were available, treatment would have been indicated for 93 infants based on IT ratio and/or CRP (n = 77) or clinical signs (n = 16), but was only initiated in 55 infants based on IL-8 and/or CRP (n = 28) or clinical signs (n = 27), an apparent reduction in "unnecessary" antibiotic therapy of 40%. CONCLUSION: The combination of IL-8 and CRP is a reliable test for the diagnosis of EOBI and may be helpful in enabling antibiotic therapy to be reduced in newborn infants.