Raman microscopic spectroscopy as a diagnostic tool to detect Staphylococcus epidermidis in bone grafts.

INTRODUCTION: Raman microscopic spectroscopyis a new approach for further characterization and detection of molecular features in many pathological processes. This technique has been successfully applied to scrutinize the spatial distribution of small molecules and proteins within biological systems by in situ analysis. This study uses Raman microscopic spectroscopyto identify any in-depth benefits and drawbacks in diagnosing Staphylococcus epidermidis in human bone grafts. MATERIAL AND METHODS: 40 non-infected human bone samples and 10 human bone samples infected with Staphylococcus epidermidis were analyzed using Raman microscopic spectroscopy. Reflectance data were collected between 200 cm-1 and 3600 cm-1 with a spectral resolution of 4 cm-1 using a Senterra II microscope (Bruker, Ettlingen, Germany). The acquired spectral information was used for spectral and unsupervised classification, such as principal component analysis. RESULTS: Raman measurements produced distinct diagnostic spectra that were used to distinguish between non-infected human bone samples and Staphylococcus epidermidis infected human bone samples by spectral and principal component analyses. A substantial loss in bone quality and protein conformation was detected by human bone samples co-cultured with Staphylococcus epidermidis. The mineral-to-matrix ratio using the phosphate/Amide I ratio (p = 0.030) and carbonate/phosphate ratio (p = 0.001) indicates that the loss of relative mineral content in bones upon bacterial infection is higher than in non-infected human bones. Also, an increase of alterations in the collagen network (p = 0.048) and a decrease in the structural organization and relative collagen in infected human bone could be detected. Subsequent principal component analyses identified Staphylococcus epidermidis in different spectral regions, respectively, originating mainly from CH2 deformation (wagging) of protein (at 1450 cm-1) and bending and stretching modes of C-H groups (∼2800-3000 cm-1). CONCLUSION: Raman microscopic spectroscopyis presented as a promising diagnostic tool to detect Staphylococcus epidermidis in human bone grafts. Further studies in human tissues are warranted.

[A multidimensional v-shaped distalizing osteotomy of the tibial tuberosity with a proximal buttress ("coffin-shaped" osteotomy)]. / Die multiplanare v-förmige distalisierende Tuberositasosteotomie mit proximalem Widerlager ("sargförmige" Osteotomie).

The aim of the intervention presented is a distalization of the tibial tuberosity. It is indicated in patients with symptomatic patella alta, i.e. patients with instability of the patella. It facilitates a V-shaped osteotomy. The bone gained during distalization is used as a proximal buttress. This leads to an improved mediolateral and proximal stability. The bony surface area is increased, which improves bony healing. There were no secondary dislocations in the patient group of 10 patients treated by the surgeon.

[Arthroscopic procedure for Baker's cysts : surgical technique. Video article]. / Arthroskopische Operation der Baker-Zyste : Operationstechnik. Videobeitrag.

BACKGROUND: Baker's cysts are related to increased intra-articular pressure. The causes may be inflammatory, degenerative or traumatic disorders. Owing to the increased intra-articular pressure a cyst protrudes between the semimembranosus and the medial gastrocnemius tendons. The traditional treatment for a Baker's cyst is open resection. As an alternative, an arthroscopic procedure can be performed, which is demonstrated by the video on surgical technique that accompanies this short report. SURGICAL TECHNIQUE: From the anterolateral portal the arthroscope is advanced through the intercondylar notch (below the posterior cruciate ligament) to the posteromedial recess. Under visual control, a posteromedial portal is created followed by identification of the capsular fold separating the cyst from the joint cavity. This fold (valvular mechanism) is resected with a shaver from the posteromedial portal until a large enough connection exists between the joint and the cyst (cyst decompression). After the decompression, the arthroscope is inserted from the posteromedial portal directly into the cyst cavity. Subsequently, the inner wall of the cyst is removed with the shaver via an additional far posterior cystic portal. It is obligatory to treat the associated intra-articular pathological condition. In our video a medial meniscal lesion is treated with partial meniscectomy.

NF-κB/STAT5/miR-155 network targets PU.1 in FLT3-ITD-driven acute myeloid leukemia.

Almost 30% of all acute myeloid leukemias (AML) are associated with an internal tandem duplication (ITD) in the juxtamembrane domain of FMS-like tyrosine kinase 3 receptor (FLT3). Patients with FLT3-ITD mutations tend to have a poor prognosis. MicroRNAs (miRNAs) have a pivotal role in myeloid differentiation and leukemia. MiRNA-155 (MiR-155) was found to be upregulated in FLT3-ITD-associated AMLs. In this study, we discovered that FLT3-ITD signaling induces the oncogenic miR-155. We show in vitro and in vivo that miR-155 expression is regulated by FLT3-ITD downstream targets nuclear factor-κB (p65) and signal transducer and activator of transcription 5 (STAT5). Further, we demonstrate that miR-155 targets the myeloid transcription factor PU.1. Knockdown of miR-155 or overexpression of PU.1 blocks proliferation and induces apoptosis of FLT3-ITD-associated leukemic cells. Our data demonstrate a novel network in which FLT3-ITD signaling induces oncogenic miR-155 by p65 and STAT5 in AML, thereby targeting transcription factor PU.1.

Activation of voltage-gated Na⁺ and Ca²âº channels is required for glutamate release from retinal glial cells implicated in cell volume regulation.

Gliotransmitters such as glutamate and ATP play an essential role in the prevention of the osmotic swelling of retinal glial (Müller) cells. It has been shown that vascular endothelial growth factor (VEGF) induces a Ca²âº-dependent release of glutamate from the cells [Wurm et al. (2008), J Neurochem 104:386-399]. In the present study, we investigated with cell swelling experiments on freshly isolated retinal glial cells of the rat whether activation of voltage-gated Na⁺ (Na(v)) and Ca²âº channels (VGCCs) is implicated in mediating the VEGF-induced release of glutamate. We found that the inhibitory effect of VEGF on the osmotic swelling of retinal glial cells, used as an indicator of glutamate release, is prevented in the presence of selective blockers of T-type VGCCs (kurtoxin, mibefradil, Ni²âº) and Na(v) channels (TTX, saxitoxin, phenytoin). In contrast, the swelling-inhibitory effect of glutamate, that is mediated by a downstream release of ATP, remained unaffected in the presence of the blockers. The cells displayed immunolabeling for VGLUT3, Ca(v)1.2, Ca(v)3.1, and Na(v)1.6. In addition to VEGF, various other receptor agonists including neuropeptide Y, progesterone, erythropoietin, and endothelin-1 evoked a VGCC- and Na(v) channel-dependent release of glutamate. It is concluded that activation of T-type VGCCs and Na(v) channels is implicated in mediating the ligand-induced release of glutamate from retinal glial cells of the rat. The involvement of VLGUTs might suggest that glutamate is released by vesicular exocytosis.

Erythropoietin inhibits osmotic swelling of retinal glial cells by Janus kinase- and extracellular signal-regulated kinases1/2-mediated release of vascular endothelial growth factor.

The volume homeostasis of retinal glial cells is mediated by an autocrine purinergic mechanism of ion channel opening which is activated in response to a decrease in the extracellular osmolarity. Here, we show that erythropoietin (EPO) prevents the osmotic swelling of glial somata in retinal slices and of isolated glial cells from control and diabetic rats, with a half-maximal effect at approximately 0.01 nM. The downstream signaling evoked by EPO includes a release of vascular endothelial growth factor from the cells which was blocked by Janus kinase and extracellular signal-regulated kinases (ERK)1/2 inhibitors. Transactivation of kinase insert domain-containing receptor/fms-like tyrosine kinase 1 (KDR/flk-1) evokes a calcium-dependent, exocytotic release of glutamate, followed by activation of group I/II metabotropic glutamate receptors which results in calcium-independent release of ATP and adenosine from the cells. The final step in this cascade is the activation of adenosine A(1) receptors which results in protein kinase A- and phosphoinositide 3-kinase-mediated opening of potassium and chloride channels. EPO receptor protein was immunohistochemically localized to the inner retina and photoreceptor inner segments. In isolated glial cells, EPO receptor protein is selectively localized to fibers which traverse the inner nuclear layer in situ. Inhibition of glial swelling might contribute to the neuroprotective action of EPO in the retina under pathological conditions.

Superheating in linear polymers studied by ultrafast nanocalorimetry.

To study phase transition kinetics on submillisecond time scale a sensitive ultrafast nanocalorimeter was constructed. Controlled ultrafast cooling, as well as heating, up to 10(6) K/s was attained. The method was applied for the measurements of the superheating phenomenon in a set of linear polymers: iPS, PBT, PET, and iPP. A power law relation between the superheating and the heating rate holds in the heating rate range 10(-2) - 10(4) K/s. A limiting superheating of about 10% of the melting temperature was observed at rates above 10(4) - 10(5) K/s. This limit depends on annealing conditions before sample melting. The observed superheating limit, as well as the power law, can be accounted for the internal stresses near the crystalline amorphous interface in semicrystalline polymers induced by heating, which are related to the thermal expansion gradients inherent in a semicrystalline material.

Breakup of shearless meanders and "outer" tori in the standard nontwist map.

The breakup of shearless invariant tori with winding number omega=(11+gamma)(12+gamma) (in continued fraction representation) of the standard nontwist map is studied numerically using Greene's residue criterion. Tori of this winding number can assume the shape of meanders [folded-over invariant tori which are not graphs over the x axis in (x,y) phase space], whose breakup is the first point of focus here. Secondly, multiple shearless orbits of this winding number can exist, leading to a new type of breakup scenario. Results are discussed within the framework of the renormalization group for area-preserving maps. Regularity of the critical tori is also investigated.

Tandem-pore domain potassium channels are functionally expressed in retinal (Müller) glial cells.

Tandem-pore domain (2P-domain) K+-channels regulate neuronal excitability, but their function in glia, particularly, in retinal glial cells, is unclear. We have previously demonstrated the immunocytochemical localization of the 2P-domain K+ channels TASK-1 and TASK-2 in retinal Müller glial cells of amphibians. The purpose of the present study was to determine whether these channels were functional, by employing whole-cell recording from frog and mammalian (guinea pig, rat and mouse) Müller cells and confocal microscopy to monitor swelling in rat Müller cells. TASK-like immunolabel was localized in these cells. The currents mediated by 2P-domain channels were studied in isolation after blocking Kir, K(A), K(D), and BK channels. The remaining cell conductance was mostly outward and was depressed by acid pH, bupivacaine, methanandamide, quinine, and clofilium, and activated by alkaline pH in a manner consistent with that described for TASK channels. Arachidonic acid (an activator of TREK channels) had no effect on this conductance. Blockade of the conductance with bupivacaine depolarized the Müller cell membrane potential by about 50%. In slices of the rat retina, adenosine inhibited osmotic glial cell swelling via activation of A1 receptors and subsequent opening of 2P-domain K+ channels. The swelling was strongly increased by clofilium and quinine (inhibitors of 2P-domain K+ channels). These data suggest that 2P-domain K+ channels are involved in homeostasis of glial cell volume, in activity-dependent spatial K+ buffering and may play a role in maintenance of a hyperpolarized membrane potential especially in conditions where Kir channels are blocked or downregulated.

Meanders and reconnection-collision sequences in the standard nontwist map.

New global periodic orbit collision and separatrix reconnection scenarios exhibited by the standard nontwist map are described in detail, including exact methods for determining reconnection thresholds, methods that are implemented numerically. Results are compared to a parameter space breakup diagram for shearless invariant curves. The existence of meanders, invariant tori that are not graphs, is demonstrated numerically for both odd and even period reconnection for certain regions in parameter space. Implications for transport are discussed.

Renormalization and destruction of 1/gamma2 tori in the standard nontwist map.

Extending the work of del-Castillo-Negrete, Greene, and Morrison [Physica D 91, 1 (1996); 100, 311 (1997)] on the standard nontwist map, the breakup of an invariant torus with winding number equal to the inverse golden mean squared is studied. Improved numerical techniques provide the greater accuracy that is needed for this case. The new results are interpreted within the renormalization group framework by constructing a renormalization operator on the space of commuting map pairs, and by studying the fixed points of the so constructed operator.

[Prevalence of medical complaints in the community-dwelling elderly receiving regular medication].

We assessed the prevalence of self-reported medical complaints among the community-dwelling elderly receiving regular medication, and determined associations between health and sociodemographic variables, and the prevalence of complaints. The study included 170 patients, 60-90 years of age, living at home. Participants were recruited from the 3 main primary care clinics in Rishon LeZion. All were receiving chronic medication and were followed-up utilizing a long-term medication card. Data were gathered in interviews held in patients' homes using a structured questionnaire which included sociodemographics, diseases and medication, mental state assessment by Katzman's score, and a list of 15 medical complaints common among the aged. Relations to age, gender, education, living arrangements, number of diseases and number of medications per patient were determined. Mean age of participants was 73.2 +/- 6.0 years and they suffered an average of 4.07 +/- 2.16 diseases and took 5.10 +/- 2.83 types of drugs. The most prevalent complaints were: weakness and fatigue (65.0%), agitation and restlessness (56.4%), dry mouth (45.6%), constipation (43.6%) and dizziness (43.2%). The number of diseases, gender, education and age had the strongest associations with the prevalence of specific complaints, as well as their total number. The association between number of medications and mean number of complaints was of borderline significance.

[Diclofenac/orphenadrine infusion therapy in patients with active arthrosis]. / Diclofenac/Orphenadrin-Infusionstherapie bei Patienten mit aktivierten Arthrosen.

This study investigated the efficacy and safety of a diclofenac/orphenadrin infusion in 21 female and 1 male patients with clinically and radiologically diagnosed inflammatory osteoarthritis of the big joints, especially the knee and hip joints. The patients received 1 infusion per day over 2 h for 10 days. Efficacy and safety were assessed by measuring the subjective pain intensity at rest and during exercise on a visual analogue scale and on an ordinal rating scale before and after every infusion. The patients were interviewed daily for possible side effects. After the 10-days treatment course a 5% reduction of pain at rest and a 37.5% reduction of pain during exercise was observed. Subjective pain intensity was reduced by an average of 32.5%. In most cases relief was noticeable after the 4th infusion. 9 patients rated the medication safety as "very good", 11 patients as "good". A total of 12 patients reported mainly mild side effects such as vertigo, dry mouth, and temporarily reduced visual acuity. Based on its rapid onset of action and its efficacy, it can be stated that the investigated diclofenac/orphenadrin infusion is a valuable extension of the therapeutic methods in patients with inflammatory osteoarthritis.

Prostacyclin increases cAMP in coronary arteries.

This study was designed to determine whether prostacyclin (PGI2)-induced relaxation in circular strips of coronary arteries might be mediated by cAMP. Partially depolarized circular strips of bovine coronary arteries were used and PGI2-induced changes in length were compared with tissue concentrations of cAMP and cGMP, measured by RIA. It was found that PGI2 produced significant and concentration dependent increases in cAMP levels which were closely associated with the relaxant effects produced by the same concentrations (0.3 - 26.7 muM). Cyclic GMP was not changed by these concentrations. The relaxant effects of PGI2 were not antagonized by propranolol. There was a significant linear correlation between log increases in cAMP and percent relaxation produced by PGI2 which was almost identical with similar correlations obtained with either isoprenaline or adenosine, indicating that the relaxant effects of PGI2 are in analogy to those of isoprenaline and adenosine likely to be mediated by cAMP.

Evidence for cyclic GMP-mediated relaxant effects of nitro-compounds in coronary smooth muscle.

The effects of the four nitro-compounds nitroglycerin, nitroprusside-Na, NaNO2 and B 744-99 were studied simultaneously on length and on cGMP-levels in isolated circular strips of bovine coronary arteries. 1. All 4 nitro-compounds concentration dependently relaxed the strips in close association with pronounced increases in cGMP-levels which preceded the mechanical responses. 2. The relaxant effects of all 4 nitro-compounds were significantly potentiated by the predominant inhibitor of cGMP-hydrolysis M & B 22,948, which also potentiated the increase in cGMP-levels of the two nitro-compounds in which it was studied (nitroglycerin and nitroprusside-Na). 3. Non-substituted cGMP and -- much stronger -- its 8 bromo-derivative also relaxed the strips and these effects were likewise potentiated by M & B 22,948. 4. When the log increase in cGMP produced by the 4 nitro-compounds were plotted against percent relaxation (probit scale) a linear and highly significant positive correlation was obtained. 5. The results provide evidence that the increases in cGMP caused by the 4 nitro-compounds studied are responsible for the smooth muscle relaxing actions of these drugs.