Study of heavy-flavor quarks produced in association with top-quark pairs at s √ =7 TeV using the ATLAS detector

Using a sample of dilepton top-quark pair (tt ¯ ) candidate events, a study is performed of the production of top-quark pairs together with heavy-flavor (HF) quarks, the sum of tt ¯ +b+X and tt ¯ +c+X , collectively referred to as tt ¯  + HF . The data set used corresponds to an integrated luminosity of 4.7  fb −1 of proton-proton collisions at a center-of-mass energy of 7 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. The presence of additional HF (b or c ) quarks in the tt ¯ sample is inferred by looking for events with at least three b -tagged jets, where two are attributed to the b quarks from the tt ¯ decays and the third to additional HF production. The dominant background to tt ¯  + HF in this sample is tt ¯ +jet events in which a light-flavor jet is misidentified as a heavy-flavor jet. To determine the heavy- and light-flavor content of the additional b -tagged jets, a fit to the vertex mass distribution of b -tagged jets in the sample is performed. The result of the fit shows that 79 ± 14 (stat) ± 22 (syst) of the 105 selected extra b -tagged jets originate from HF quarks, 3 standard deviations away from the hypothesis of zero tt ¯  + HF production. The result for extra HF production is quoted as a ratio (R HF ) of the cross section for tt ¯  + HF production to the cross section for tt ¯ production with at least one additional jet. Both cross sections are measured in a fiducial kinematic region within the ATLAS acceptance. R HF is measured to be [6.2±1.1(stat)±1.8(syst)]% for jets with p T >25  GeV and |η|<2.5 , in agreement with the expectations from Monte Carlo generators.

Human melanocytes can be isolated, propagated and expanded from plucked anagen hair follicles

Herein, we report a technically simple method for isolation and culture of human follicular melanocytes based on explant cultures of epilated hair follicles. This technique does not require any surgical intervention and allows the isolation and cultivation of follicular melanocytes from a comparatively small amount of raw material. Generally, 30-60 human anagen hair follicles have been plucked from the scalp of healthy donors and cultivated under low oxygen pressure (5%). After a short period of time cells of various types were growing out from the outer root sheath (ORS) of the hair follicles. Under the selected culture conditions, most of the cells other than melanocytes have been eliminated and a nearly 100% pure population of melanocytes has been achieved, as confirmed by immunohistochemical analyses for melanocyte-specific markers, for example, Tyrosinase-1, S-100 and premelanosomal antigens. These melanocytes derived from the ORS were proliferating for up to 2 months.

[Thyroid nodules: which further investigations should be done]

Thyroid nodules are a very common clinical finding with an age-related increase in prevalence. The clinical detection of thyroid nodules is outnumbered by the ultrasonographic assessment of thyroid nodules. The clinical challenge is to exclude thyroid cancer and clinical or subclinical hyperthyroidism. Ultrasonography is the first imaging study in all patients with palpable nodules; their size and TSH determine further diagnostic evaluations. Fine-needle aspiration (cytology) is recommended in euthyroid patients of nodules measuring more than 1-1.5 cm in diameter. Nodules more than 4 cm in diameter have to be removed surgically without preceding cytological examination. Without risk factors thyroid nodules are followed by clinical examination and ultrasonography every 6-12 months, in case of symptoms or rapid growth a follow-up assessment should be done earlier.

Quantitative analysis of O(6)-methylguanine DNA methyltransferase (MGMT) promoter methylation in patients with low-grade gliomas

Methylation of the MGMT promoter is supposed to be a predictive and prognostic factor in glioblastoma. Whether MGMT promoter methylation correlates with tumor response to temozolomide in low-grade gliomas is less clear. Therefore, we analyzed MGMT promoter methylation by a quantitative methylation-specific PCR in 22 patients with histologically verified low-grade gliomas (WHO grade II) who were treated with temozolomide (TMZ) for tumor progression. Objective tumor response, toxicity, and LOH of microsatellite markers on chromosomes 1p and 19q were analyzed. Histological classification revealed ten oligodendrogliomas, seven oligoastrocytomas, and five astrocytomas. All patients were treated with TMZ 200 mg/m2 on days 1-5 in a 4 week cycle. The median progression-free survival was 32 months. Combined LOH 1p and 19q was found in 14 patients; one patient had LOH 1p alone and one patient LOH 19q alone. The LOH status could not be determined in two patients and was normal in the remaining four. LOH 1p and/or 19q correlated with longer time to progression but not with radiological response to TMZ. MGMT promoter methylation was detectable in 20 patients by conventional PCR and quantitative analysis revealed the methylation status was between 12 and 100%. The volumetric response to chemotherapy analyzed by MRI and time to progression correlated with the level of MGMT promoter methylation. Therefore, our retrospective case series suggests that quantitative methylation-specific PCR of the MGMT promoter predicts radiological response to chemotherapy with TMZ in WHO grade II gliomas.

Rapid induction of remission in large vessel vasculitis by IL-6 blockade. A case series

OBJECTIVE: To evaluate the effect of IL-6 blockade using tocilizumab in inducing remission of arterial large vessel vasculitides (LVV). METHODS: Five consecutive patients with giant-cell arteritis (GCA) and two with Takayasu’s arteritis (TA) were treated by tocilizumab infusions (8 mg/kg). Tocilizumab was given every other week for the first month and once monthly thereafter. Clinical symptoms of disease activity, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level and glucocorticoid (GC) dosage necessary to maintain remission were prospectively assessed. MR angiography was performed to monitor local inflammation. RESULTS: Of the seven patients three were newly diagnosed and four showed GC resistance, i.e. GC could not be lowered to less than 7.5 mg/day. The mean follow-up time was 4.3 months (range 3–7 months). All patients achieved a rapid and complete clinical response and normalisation of the acute phase proteins. Remarkably, prednisone dosage could be reduced within 12 weeks to a mean of 2.5 mg/day (range 0–10 mg/day). No relapse and no drug-related side effects were noted. CONCLUSION: Collectively the data suggest that IL-6 blockade using tocilizumab qualifies as a therapeutic option to induce rapid remission in large vessel vasculitides.

How should bladder wall thickness be measured? A comparison of vaginal, perineal and abdominal ultrasound

Measurement of bladder wall thickness using transvaginal ultrasound has previously been shown to discriminate between women with diagnosed detrusor overactivity and those with urodynamic stress incontinence. So far, no comparison has been made between abdominal, perineal and vaginal route for the measurement of bladder wall thickness. The aim of this prospective study was to determine if abdominal, perineal and vaginal ultrasound measurements of bladder wall thickness are comparable with each other.

Parallel synthesis and nucleic acid binding properties of C(6')-[alpha]-functionalized bicyclo-DNA

Two novel bicyclo-T nucleosides carrying a hydroxyl or a carboxymethyl substituent in C(6')-[alpha]-position were prepared and incorporated into oligodeoxynucleotides. During oligonucleotide deprotection the carboxymethyl substituent was converted into different amide substituents in a parallel way. Tm-measurements showed no dramatic differences in both, thermal affinity and mismatch discrimination, compared to unmodified oligonucleotides. The post-synthetic modification of the carboxymethyl substituent allows in principle for a parallel preparation of a library of oligonucleotides carrying diverse substituents at C(6'). In addition, functional groups can be placed into unique positions in a DNA double helix.

Validation of the Swiss Monte Carlo Plan for a static and dynamic 6 MV photon beam

Monte Carlo (MC) based dose calculations can compute dose distributions with an accuracy surpassing that of conventional algorithms used in radiotherapy, especially in regions of tissue inhomogeneities and surface discontinuities. The Swiss Monte Carlo Plan (SMCP) is a GUI-based framework for photon MC treatment planning (MCTP) interfaced to the Eclipse treatment planning system (TPS). As for any dose calculation algorithm, also the MCTP needs to be commissioned and validated before using the algorithm for clinical cases. Aim of this study is the investigation of a 6 MV beam for clinical situations within the framework of the SMCP. In this respect, all parts i.e. open fields and all the clinically available beam modifiers have to be configured so that the calculated dose distributions match the corresponding measurements. Dose distributions for the 6 MV beam were simulated in a water phantom using a phase space source above the beam modifiers. The VMC++ code was used for the radiation transport through the beam modifiers (jaws, wedges, block and multileaf collimator (MLC)) as well as for the calculation of the dose distributions within the phantom. The voxel size of the dose distributions was 2mm in all directions. The statistical uncertainty of the calculated dose distributions was below 0.4%. Simulated depth dose curves and dose profiles in terms of [Gy/MU] for static and dynamic fields were compared with the corresponding measurements using dose difference and γ analysis. For the dose difference criterion of ±1% of D(max) and the distance to agreement criterion of ±1 mm, the γ analysis showed an excellent agreement between measurements and simulations for all static open and MLC fields. The tuning of the density and the thickness for all hard wedges lead to an agreement with the corresponding measurements within 1% or 1mm. Similar results have been achieved for the block. For the validation of the tuned hard wedges, a very good agreement between calculated and measured dose distributions was achieved using a 1%/1mm criteria for the γ analysis. The calculated dose distributions of the enhanced dynamic wedges (10°, 15°, 20°, 25°, 30°, 45° and 60°) met the criteria of 1%/1mm when compared with the measurements for all situations considered. For the IMRT fields all compared measured dose values agreed with the calculated dose values within a 2% dose difference or within 1 mm distance. The SMCP has been successfully validated for a static and dynamic 6 MV photon beam, thus resulting in accurate dose calculations suitable for applications in clinical cases.

Influence of V5/6-His Tag on the Properties of Gap Junction Channels Composed of Connexin43, Connexin40 or Connexin45

HeLa cells expressing wild-type connexin43, connexin40 or connexin45 and connexins fused with a V5/6-His tag to the carboxyl terminus (CT) domain (Cx43-tag, Cx40-tag, Cx45-tag) were used to study connexin expression and the electrical properties of gap junction channels. Immunoblots and immunolabeling indicated that tagged connexins are synthesized and targeted to gap junctions in a similar manner to their wild-type counterparts. Voltage-clamp experiments on cell pairs revealed that tagged connexins form functional channels. Comparison of multichannel and single-channel conductances indicates that tagging reduces the number of operational channels, implying interference with hemichannel trafficking, docking and/or channel opening. Tagging provoked connexin-specific effects on multichannel and single-channel properties. The Cx43-tag was most affected and the Cx45-tag, least. The modifications included (1) V j-sensitive gating of I j (V j, gap junction voltage; I j, gap junction current), (2) contribution and (3) kinetics of I j deactivation and (4) single-channel conductance. The first three reflect alterations of fast V j gating. Hence, they may be caused by structural and/or electrical changes on the CT that interact with domains of the amino terminus and cytoplasmic loop. The fourth reflects alterations of the ion-conducting pathway. Conceivably, mutations at sites remote from the channel pore, e.g., 6-His-tagged CT, affect protein conformation and thus modify channel properties indirectly. Hence, V5/6-His tagging of connexins is a useful tool for expression studies in vivo. However, it should not be ignored that it introduces connexin-dependent changes in both expression level and electrophysiological properties.

Bilateral total extraperitoneal inguinal hernia repair (TEP) has outcomes similar to those for unilateral TEP: population-based analysis of prospective data of 6,505 patients

Whether bilateral total extraperitoneal (TEP) inguinal hernia repair is associated with worse outcomes than unilateral TEP continues to be a matter of debate. This study aimed to compare different outcomes of large cohorts of patients undergoing bilateral versus unilateral TEP.

Cervical muscle area measurements in whiplash patients: Acute, 3, and 6 months of follow-up

To investigate the role of the cervical spine muscles in whiplash injury. We hypothesized that (i) cervical muscle hypotrophy would be evident after a 6-month follow-up and, (ii) cervical muscle hypotrophy would correlate with symptom persistence probably related to pain or inactivity.

Stromal cell-associated expression of kallikrein-related peptidase 6 (KLK6) indicates poor prognosis of ovarian cancer patients

Several members of the human kallikrein-related peptidase family, including KLK6, are up-regulated in ovarian cancer. High KLK6 mRNA or protein expression, measured by quantitative polymerase chain reaction and enzyme-linked immunoassay, respectively, was previously found to be associated with a shortened overall and progression-free survival (OS and PFS, respectively). In the present study, we aimed at analyzing KLK6 protein expression in ovarian cancer tissue by immunohistochemistry. Using a newly developed monospecific polyclonal antibody, KLK6 immunoexpression was initially evaluated in normal tissues. We observed strong staining in the brain and moderate staining in the kidney, liver, and ovary, whereas the pancreas and the skeletal muscle were unreactive, which is in line with previously published results. Next, both tumor cell- and stromal cell-associated KLK6 immunoexpression were analyzed in tumor tissue specimens of 118 ovarian cancer patients. In multivariate Cox regression analysis, only stromal cell-associated expression, besides the established clinical parameters FIGO stage and residual tumor mass, was found to be statistically significant for OS and PFS [high vs. low KLK6 expression; hazard ratio (HR), 1.92; p=0.017; HR, 1.80; p=0.042, respectively]. These results indicate that KLK6 expressed by stromal cells may considerably contribute to the aggressiveness of ovarian cancer.