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Background: The sensitive and accurate detection of hepatitis B virus surface antigen (HBsAg) is critical to the identification of infection and the prevention of transfusion transmitted disease. Improvement in HBsAg assay sensitivity is essential to reduce the window to detect an acute HBV infection. Additionally, the sensitive detection of HBsAg mutants that continue to evolve due to vaccine escape, immune selection and an error prone reverse transcriptase is a necessity., Objectives and Study Design: A fully automated HBsAg prototype assay on the Abbott ARCHITECT instrument was developed to improve sensitivity and mutant detection. This magnetic microparticle-based assay utilizes anti-HBsAg monoclonal antibodies to capture antigen present in serum or plasma. Captured antigen is then detected using anti-HBsAg antibody conjugated with the chemiluminescent compound, acridinium., Results: The sensitivity of the ARCHITECT HBsAg prototype assay was improved as compared to the current ARCHITECT, PRISM, and competitor HBsAg assays. The enhancement in assay sensitivity was demonstrated by the use of commercially available HBV seroconversion panels. The prototype assay detected more panel members (185 of 383) vs. the current ARCHITECT (171), PRISM (181), or competitor HBsAg assays (73/140 vs. 62/140, respectively). The ARCHITECT prototype assay also efficiently detected all mutants evaluated. Finally, the sensitivity improvement did not compromise the specificity of the assay (99.94%)., Conclusions: An improved Abbott ARCHITECT HBsAg prototype assay with enhanced detection of HBsAg and HBsAg mutants, as well as equivalent specificity was developed for the detection, diagnosis, and management of HBV infection., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Purpose: Medulloblastomas are heterogeneous and include relatively good-prognosis tumors characterized by Wnt pathway activation, as well as those that cannot be successfully treated with conventional therapy. Developing a practical therapeutic stratification that allows accurate identification of disease risk offers the potential to individualize adjuvant therapy and to minimize long-term adverse effects in a subgroup of survivors., Methods: Using formalin-fixed paraffin-embedded (FFPE) tissue for immunohistochemistry, fluorescent in situ hybridization, and direct sequencing to identify tumors with a Wnt pathway signature and those harboring copy number abnormalities (CNAs) of potential prognostic significance (MYC/MYCN amplification, CNAs of chromosome 6 and 17), we evaluated clinical, pathologic, and molecular outcome indicators and stratification models in a cohort (n = 207) of patients with medulloblastoma 3 to 16 years of age from the International Society of Pediatric Oncology CNS9102 (PNET3) trial., Results: Metastatic disease and large-cell/anaplastic (LC/A) phenotype were the clinicopathologic variables associated with poor progression-free survival (PFS). Nuclear immunoreactivity for β-catenin, CTNNB1 mutation, and monosomy 6 all identified a group of good-prognosis patients. MYC amplification was associated with poor outcome, but other CNAs were not. Low-risk medulloblastomas were defined as β-catenin nucleopositive tumors without metastasis at presentation, LC/A phenotype, or MYC amplification. High-risk medulloblastomas were defined as tumors with metastatic disease, LC/A phenotype, or MYC amplification. Low-risk, standard-risk, and high-risk categories of medulloblastoma had significantly (P < .0001) different outcomes., Conclusion: Integrating assays of molecular biomarkers undertaken on routinely collected diagnostic FFPE tissue into stratification schemes for medulloblastoma alongside clinical and pathologic outcome indicators can refine current definition of disease risk and guide adjuvant therapy.

Medulloblastoma is heterogeneous, being characterized by molecular subgroups that demonstrate distinct gene expression profiles. Activation of the WNT or SHH signaling pathway characterizes two of these molecular subgroups, the former associated with low-risk disease and the latter potentially targeted by novel SHH pathway inhibitors. This manuscript reports the validation of a novel diagnostic immunohistochemical method to distinguish SHH, WNT, and non-SHH/WNT tumors and details their associations with clinical, pathological and cytogenetic variables. A cohort (n = 235) of medulloblastomas from patients aged 0.4-52 years was studied for expression of four immunohistochemical markers: GAB1, β-catenin, filamin A, and YAP1. Immunoreactivity (IR) for GAB1 characterizes only SHH tumors and nuclear IR for β-catenin only WNT tumors. IRs for filamin A and YAP1 identify SHH and WNT tumors. SHH, WNT, and non-SHH/WNT tumors contributed 31, 14, and 55% to the series. All desmoplastic/nodular (D/N) medulloblastomas were SHH tumors, while most WNT tumors (94%) had a classic phenotype. Monosomy 6 was strongly associated with WNT tumors, while PTCH1 loss occurred almost exclusively among SHH tumors. MYC or MYCN amplification and chromosome 17 imbalance occurred predominantly among non-SHH/WNT tumors. Among patients aged 3-16 years and entered onto the SIOP PNET3 trial, outcome was significantly better for children with WNT tumors, when compared to SHH or non-SHH/WNT tumors, which showed similar survival curves. However, high-risk factors (M+ disease, LC/A pathology, MYC amplification) significantly influenced survival in both SHH and non-SHH/WNT groups. We describe a robust method for detecting SHH, WNT, and non-SHH/WNT molecular subgroups in formalin-fixed medulloblastoma samples. In corroborating other studies that indicate the value of combining clinical, pathological, and molecular variables in therapeutic stratification schemes for medulloblastoma, we also provide the first outcome data based on a clinical trial cohort and novel data on how molecular subgroups are distributed across the range of disease.

The study aimed to examine the tolerability of the combination of radiotherapy and tamoxifen and the effect on median and event free survival as well as collecting data on the use of steroids in this population. 31 patients with diffuse intrinsic pontine glioma, diagnosed on clinical and radiological criteria, were treated with high-dose oral tamoxifen (120 mg/m(2)/day) given concomitantly with standard dose radiotherapy (54 Gy in 1.8 Gy fractions over 6 weeks). Results Tamoxifen was well tolerated with no grade 3 or 4 CTC toxicity reported. At 1 year, the progression free and event free survival were 3.2% (95% CI: 0.2-14.1%), and at 6 months 19.4% (CI: 7.9% to 34.6%). The overall survival at 1 year was 16.1% (CI: 5.9-30.9%) with median survival 6.32 months. In this study, in which tamoxifen was used in conjunction with radiotherapy, progression free survival was shown to be less good when compared with historical data HR = 3.1 (CI: 1.7-5.7). There was no significant reduction in overall survival. The addition of high-dose tamoxifen, although well tolerated, confers no clinical benefit to patients treated with diffuse intrinsic pontine glioma treated with standard radiotherapy.

Although strong positive association between alcoholism and depression is a common epidemiological observance, the causal relationship and the neurobiological substrates of such observations are far from clear. We have reported that chronic daily exposure to a relatively high dose of alcohol in rats can induce or exacerbate an already existing depressive-like behavior (Pharm Biochem Behav 91:97-103, 2008). Moreover, these effects of alcohol were blocked by pretreatment with desipramine, a tricyclic antidepressant, implicating a role for the biogenic amines in this type of depressive symptoms. In order to further delineate the involvement of specific neurotransmitters in alcohol-induced depressive symptoms, we examined the concentrations of norepinephrine (NE), dopamine (DA) and serotonin (5-HT) in the frontal cortex and hippocampus following alcohol administration as well as pretreatment with two antidepressants, nomifensine and imipramine selective NE/DA and NE/5-HT uptake inhibitors, respectively. Adult female Wistar and Wistar-Kyoto (WKY) rats were exposed to alcohol via inhalation chambers (3h/day for 10 days) to achieve daily blood alcohol concentration of approximately 150 mg%. On day 11, the animals were evaluated for general locomotor activity (LCA) and performance in the forced swim test (FST), followed by neurochemical analyses. As expected WKY rats had lower LCA and higher immobility in the FST compared to Wistar rats. WKY rats also had lower levels of all three biogenic amines compared to Wistar rats in both areas. However, only cortical NE was reduced in both strains following alcohol administration. Treatments with nomifensine and imipramine blocked the behavioral and most of the neurochemical deficits caused by alcohol in both strains. These results implicate cortical NE as a major player in alcohol-induced depression. Moreover, it is suggested that selective NE uptake inhibitors may be of particular therapeutic potential in co-morbid condition of alcoholism and depression., ((c) 2010 Elsevier Inc. All rights reserved.)

Rotary biomolecular machines rely on highly symmetric supramolecular structures with rotating units that operate within a densely packed frame of reference, stator, embedded within relatively rigid membranes. The most notable examples are the enzyme FoF1 ATP synthase and the bacterial flagellum, which undergo rotation in steps determined by the symmetries of their rotators and rotating units. Speculating that a precise control of rotational dynamics in rigid environments will be essential for the development of artificial molecular machines, we analyzed the relation between rotational symmetry order and equilibrium rotational dynamics in a set of crystalline molecular gyroscopes with rotators having axial symmetry that ranges from two- to fivefold. The site exchange frequency for these molecules in their closely related crystals at ambient temperature varies by several orders of magnitude, up to ca. 4.46 x 10(8) s(-1).

The nonhuman sialic acid N-glycolylneuraminic acid (Neu5Gc) is metabolically incorporated into human tissues from certain mammalian-derived foods, and this occurs in the face of an anti-Neu5Gc "xeno-autoantibody" response. Given evidence that this process contributes to chronic inflammation in some diseases, it is important to understand when and how these antibodies are generated in humans. We show here that human anti-Neu5Gc antibodies appear during infancy and correlate with weaning and exposure to dietary Neu5Gc. However, dietary Neu5Gc alone cannot elicit anti-Neu5Gc antibodies in mice with a humanlike Neu5Gc deficiency. Other postnatally appearing anti-carbohydrate antibodies are likely induced by bacteria expressing these epitopes; however, no microbe is known to synthesize Neu5Gc. Here, we show that trace exogenous Neu5Gc can be incorporated into cell surface lipooligosaccharides (LOS) of nontypeable Haemophilus influenzae (NTHi), a human-specific commensal/pathogen. Indeed, infant anti-Neu5Gc antibodies appear coincident with antibodies against NTHi. Furthermore, NTHi that express Neu5Gc-containing LOS induce anti-Neu5Gc antibodies in Neu5Gc-deficient mice, without added adjuvant. Finally, Neu5Gc from baby food is taken up and expressed by NTHi. As the flora residing in the nasopharynx of infants can be in contact with ingested food, we propose a novel model for how NTHi and dietary Neu5Gc cooperate to generate anti-Neu5Gc antibodies in humans.

Recombinant glycoprotein therapeutics produced in nonhuman mammalian cell lines and/or with animal serum are often modified with the nonhuman sialic acid N-glycolylneuraminic acid (Neu5Gc; refs. 1,2). This documented contamination has generally been ignored in drug development because healthy individuals were not thought to react to Neu5Gc (ref. 2). However, recent findings indicate that all humans have Neu5Gc-specific antibodies, sometimes at high levels. Working with two monoclonal antibodies in clinical use, we demonstrate the presence of covalently bound Neu5Gc in cetuximab (Erbitux) but not panitumumab (Vectibix). Anti-Neu5Gc antibodies from healthy humans interact with cetuximab in a Neu5Gc-specific manner and generate immune complexes in vitro. Mice with a human-like defect in Neu5Gc synthesis generate antibodies to Neu5Gc after injection with cetuximab, and circulating anti-Neu5Gc antibodies can promote drug clearance. Finally, we show that the Neu5Gc content of cultured human and nonhuman cell lines and their secreted glycoproteins can be reduced by adding a human sialic acid to the culture medium. Our findings may be relevant to improving the half-life, efficacy and immunogenicity of glycoprotein therapeutics.

An efficient, convergent synthetic strategy has been developed which enables the synthesis of a series of naturally occurring isotactic polymethoxy compounds. Ether transfer followed by a hydride workup enables simultaneous, diastereoselective production of two methoxy centers in a single step. High yields and diastereoselectivity are observed even in stereochemically rich, polyoxygenated systems. Direct generation of bis-methyl ether moieties from methoxymethyl ethers minimizes the need for typical protective group strategies and the use of expensive methyl transfer reagents. Moreover, the simultaneous generation of a terminal primary iodide serves as a coupling partner for the generation of higher order congeners.

Background: Hepatitis C virus (HCV) infection may be associated with thrombocytopenia and increased iron stores in patients receiving medical care. We aimed to determine how often changes in hematologic, iron metabolic and inflammatory markers occur in individuals with undiagnosed HCV in the community., Methods: Inner-city African Americans (n=143) were recruited from the community according to reported ingestion of alcohol. They were divided broadly into those who drank more or less than 56 g alcohol/day as assessed by dietary questionnaire. HCV serology was determined and laboratory values were compared according to HCV seropositivity in analyses that adjusted for alcohol consumption., Results: The prevalence of HCV seropositivity was 23% among men and 29% among women. Levels of hepatocellular enzymes were higher with HCV seropositivity (P<0.0001) but hemoglobin concentrations, white blood cell and platelet counts and serum ferritin concentrations did not differ. The globulin fraction of the serum protein concentration (P=0.002) was increased with HCV seropositivity as expected with chronic inflammation. However, erythrocyte sedimentation rate and serum iron and haptoglobin levels did not differ significantly according to HCV status. Furthermore, multivariate analysis revealed that C-reactive protein was decreased and transferrin concentration was increased with both HCV and alcohol consumption (P<0.014)., Conclusions: Previously undiagnosed HCV seropositivity has little effect on the complete blood count and body iron stores but appears to perturb the response to an inflammatory stimulus, causing reduced rather than increased circulating CRP concentrations and increased rather than decreased transferrin concentrations., (Copyright 2010 Elsevier B.V. All rights reserved.)

A concise total synthesis of (S)-14-methoxyepothilone D has been accomplished. (S)-14-Methoxyepothilone D represents a conceptually novel example of polyketide analogue design based on an alternative biogenetic pattern of extender units. The significant biological activity observed for this compound provides a foundation to support studies designed to prepare derivatives of this type through fermentation of genetically engineered organisms expressing the epothilone PKS gene cluster.

Background and Purpose: To evaluate the impact of radiotherapy (RT) parameters on outcome in the SIOP/UKCCSG study of pre-RT chemotherapy for Supratentorial Primitive Neuro-ectodermal Tumours., Methods and Materials: Sixty-two patients aged 2.9-16.6 (median 6.4 years) were eligible. Forty-eight (77%) had non-pineal sites and 14 (23%) had pineal sites. Eleven were randomized to RT alone (6) and five to pre-RT Vincristine, Etoposide, Carboplatin and Cyclophosphamide. Fifty-one were not randomized, 15 receiving RT alone and 36 receiving pre-RT chemotherapy. Craniospinal RT (CSRT) 35 Gy/21 fractions were followed by 20 Gy/12 fractions to primary tumour., Results: Mean CSRT dose was 34.7 Gy and mean total primary dose was 53.4 Gy for those who received radiotherapy. Of 30 relapses, 18 (60%) were local only and 5 (16.7%) were combined local and leptomeningeal. There was no significant impact on Overall Survival (OS) or Event-Free Survival (EFS) of surgery-RT interval for patients treated by pre-RT chemotherapy or RT alone, or duration of RT (completing within 50 days). Planning films were received for 42/54 (77.8%) patients. Fourteen (33%) had one or more targeting deviations (10 cribriform fossa, 11 base of skull). There was a statistically significant increase in the risk of recurrence for patients with cribriform fossa targeting deviations (p=0.033), but not for patients with base of skull targeting deviations (p=0.242). There was no statistically significant difference in OS (p=0.0598) or EFS (p=0.0880) for patients who had one or more targeting deviations compared to those who had none., Conclusions: This study has not demonstrated a statistically significant impact of radiotherapy duration or targeting deviations on OS or EFS, possibly due to small patient numbers. However, multi-institutional SPNET trials should incorporate quality assurance programs including analysis of relapse pattern in relation to primary target volume coverage.

This manuscript is driven by the need to understand the fundamental mechanisms that cause twisted bone growth and shoulder pain in high performance tennis players. Our ultimate goal is to predict bone mass density in the humerus through computational analysis. The underlying study spans a unique four level complete analysis consisting of a high-speed video analysis, a musculoskeletal analysis, a finite element based density growth analysis and an X-ray based bone mass density analysis. For high performance tennis players, critical loads are postulated to occur during the serve. From high-speed video analyses, the serve phases of maximum external shoulder rotation and ball impact are identified as most critical loading situations for the humerus. The corresponding posts from the video analysis are reproduced with a musculoskeletal analysis tool to determine muscle attachment points, muscle force vectors and overall forces of relevant muscle groups. Collective representative muscle forces of the deltoid, latissimus dorsi, pectoralis major and triceps are then applied as external loads in a fully 3D finite element analysis. A problem specific nonlinear finite element based density analysis tool is developed to predict functional adaptation over time. The density profiles in response to the identified critical muscle forces during serve are qualitatively compared to X-ray based bone mass density analyses.

A Monte Carlo study of dosimetry for eye plaque brachytherapy is performed. BrachyDose, an EGSnrc user code which makes use of Yegin's multi-geometry package, is used to fully model 125I (model 6711) and 103Pd (model 200) brachytherapy seeds and the standardized plaques of the Collaborative Ocular Melanoma Study (COMS). Three-dimensional dose distributions in the eye region are obtained. In general, dose to water is scored; however, the implications of replacing water with eye tissues are explored. The effect of the gold alloy (Modulay) backing is investigated and the dose is found to be sensitive to the elemental composition of the backing. The presence of the silicone polymer (Silastic) seed carrier results in substantial dose decreases relative to water, particularly for 103Pd. For a 20 mm plaque with a Modulay backing and Silastic insert, fully loaded with 24 seeds, the dose decrease relative to water is of the order of 14% for 125I and 20% for 103Pd at a distance of 1 cm from the inner sclera along the plaque's central axis. For the configurations of seeds used in COMS plaques, interseed attenuation is a small effect within the eye region. The introduction of an air interface results in a dose reduction in its vicinity which depends on the plaque's position within the eye and the radionuclide. Introducing bone in the eye's vicinity also causes dose reductions. The dose distributions in the eye for the two different radionuclides are compared and, for the same prescription dose, 103Pd generally offers a lower dose to critical normal structures. BrachyDose is sufficiently fast to allow full Monte Carlo dose calculations for routine clinical treatment planning.

Background: Malt liquor (ML) beverages have become increasingly popular among urban minority groups, due partly to their inexpensive price and targeted advertising. We hypothesized that nonfermented by-products contained in ML beverages will alter the pharmacokinetics (PK) and pharmacodynamic (PD) effects of its ethanol content. In addition, we determined the effect of alcohol dehydrogenase (ADH) genotypes on the PK following consumption of ML beverages., Methods: The study was conducted in 31 healthy adult African-American social drinkers, mean +/- SD age of 22.3 +/- 1.3 years, and weight of 70.7 +/- 10.9 kg. Participants were administered ethanol, in randomized order, 2-weeks apart, in the form of oral ML beverage (6%v/v), or isocaloric solution of diet soda-ethanol (DS-Etoh) beverage (6%v/v). During each session the beverage was consumed over 4 minutes and breath alcohol concentrations (BrAC) as well as subjective and behavioral effects of ethanol were evaluated over 180 minutes. Pharmacokinetic parameters of ethanol were calculated using Michaelis-Menten elimination kinetics. The effect of ML and ADH genotype on PK was evaluated using the Wilcoxon rank-sum test and the Wilcoxon signed rank test, respectively., Results: Results show a slower mean rate of absorption, K(a), (0.12 vs. 0.15 min(-1), p = 0.03) and a longer time to reach maximum concentration, T(max), (28 vs. 23 minute, p < 0.01) for the ML compared with DS-Etoh beverage. The ML beverage resulted in a larger area under the BrAC-time curve compared with DS-Etoh beverage (8.4 vs. 6.8 min g/dl, p = 0.02). There was no difference in the subjective PD effects between the 2 beverages., Conclusion: Results show that exposure to ethanol following the consumption of ML beverages is different compared to that following nonmalt beverages in African-Americans. These differences may be related to nonfermented by-products present in commercially available ML products. These PK differences do not appear to result in significant perceived alcohol PD changes, nor are they related to ADH genotype.

A concise total synthesis of neopeltolide macrolactone has been accomplished in 14 steps in the longest linear sequence, 15 steps overall from commercially available materials. The present synthesis was highlighted by successful exploitation of ether transfer methodology and a radical cyclization reaction to directly establish the requisite stereochemistry of the tetrahydropyran core.

Epidemiological studies indicate significant co-morbid expression of alcoholism, anxiety, and depression. These symptoms are often under-diagnosed and under-treated and can worsen prognostic and treatment outcome for alcoholism. Nonetheless, a causal relationship between alcoholism and these conditions is yet to be established. In this study we sought to determine the effects of daily alcohol administration on the indices of anxiety and depression in two rat strains, one of which exhibits inherent depressive-like characteristics. Moreover, it was of relevance to examine the effects of a clinically useful antidepressant on alcohol-induced behavioral changes. Wistar-Kyoto (WKY) rats derived from Wistar stock show low levels of locomotor activity in an open field and high levels of immobility in the forced swim test (FST) which is considered a measure of their helplessness and hence are considered a putative animal model of depression. Adult female WKY and Wistar rats were exposed for 3 hrs daily to 95% ethanol vapor to achieve a mean blood alcohol level (BAL) of approximately 150 mg/dL. Controls were exposed to air in similar inhalation chambers. Sixteen to 18 hrs following 7 or 14 days of exposure to alcohol, locomotor activity (LCA) in open field, duration of time spent in the open arm of the elevated plus-maze (EPM), reflective of anxiety-like behavior and immobility in FST were evaluated. Alcohol exposure for 7 or 14 days reduced LCA only in Wistar rats but enhanced FST immobility in both strains at both time points. Only 14 day alcohol exposure reduced EPM open arm time in both WKY and Wistar rats. Daily treatment with desipramine (8 mg/kg) blocked all the changes induced by alcohol in both strains. Thus, subchronic (7 day) exposure to alcohol induces depressive-like characteristics in Wistar rats and exacerbates that of WKY rats. Chronic (14 day) exposure, however, also induces an anxiety-like effect in both strains. The depressive- and anxiety-like behaviors induced by alcohol were blocked by daily treatment with a tricyclic antidepressant. It may be suggested that prophylactic treatment of alcoholics with an antidepressant prior to detoxification may improve treatment outcome for alcoholism.

This study presents the results of EGSnrc Monte Carlo calculations of the dose distribution surrounding a high dose rate 169Yb brachytherapy source and 14 high dose rate and pulsed dose rate 192Ir brachytherapy sources. Energy-weighted spectra of emitted photons, a full set of TG-43 dosimetry parameters, along-away dose tables, and a description of the materials and geometry used for each source are provided. In addition to this, separate tallies are made of the dose contributed from primary, single-scattered, and multiply-scattered photons. Separation of dose in this manner allows one to use convolution/superposition methods to calculate the dose surrounding a brachytherapy source accounting for a non-homogeneous medium. The effect of phantom size on TG-43 dosimetry parameters and scattered dose is also investigated for the 192Ir microSelectron v2 HDR source. This paper describes the calculation methods and presents the dose rate constants calculated for each source with the full set of dosimetry data being available online at the Carleton Laboratory for Radiotherapy Physics brachytherapy database (http://www.physics.carleton.ca/clrp/seed&#95;database/).

This Highlight covers the chemical and biological studies regarding a set of polyketide inhibitors of eukaryotic protein synthesis related to the marine-derived cytotoxic agent tedanolide.

In this study an improved functional form for fitting the radial dose functions, g(r), of 125I and 103Pd brachytherapy seeds is presented. The new function is capable of accurately fitting radial dose functions over ranges as large as 0.05 cm < or = r < or = 10 cm for 125I seeds and 0.10 cm < or = r < or = 10 cm for 103Pd seeds. The average discrepancies between fit and calculated data are less than 0.5% over the full range of fit and maximum discrepancies are 2% or less. The fitting function is also capable of accounting for the sharp increase in g(r) (upturn) seen for some sources for r < 0.1 cm. This upturn has previously been attributed to the breakdown of the approximation of the sources as a line, however, in this study we demonstrate that another contributing factor is the 4.5 keV characteristic x-rays emitted from the Ti seed casing. Radial dose functions are calculated for 18 125I seeds and 9 103pd seeds using the EGSnrc Monte Carlo user-code BrachyDose. Fitting coefficients of the new function are tabulated for all 27 seeds. Extrapolation characteristics of the function are also investigated. The new functional form is an improvement over currently used fitting functions with its main strength being the ability to accurately fit the rapidly varying radial dose function at small distances. The new function is an excellent candidate for fitting the radial dose function of all 103Pd and 125I brachytherapy seeds and will increase the accuracy of dose distributions calculated around brachytherapy seeds using the TG-43 protocol over a wider range of data. More accurate values of g(r) for r < 0.5 cm may be particularly important in the treatment of ocular melanoma.

Monte Carlo methods are used to calculate a complete TG-43 dosimetry parameter data set for 27 low-energy photon emitting brachytherapy sources (18 125I and 9 l03Pd). All Monte Carlo calculations are performed using the EGSnrc user-code BrachyDose. TG-43 dosimetry parameters, including dose rate constants, radial dose functions (with functional fitting parameters), and anisotropy data, are calculated with finer spatial resolution, greater range of distances, and smaller uncertainties than data currently available in the literature for many of these sources. In particular, for most of the seeds, this is the first time that anisotropy data have been tabulated at distances less than 0.5 cm from the source. These calculations employ the state-of-the-art XCOM photon cross sections, and detailed source geometries are modeled using Yegin's multigeometry package. This data set serves as a completely independent verification of the currently available dosimetry parameters calculated using other Monte Carlo codes, including MCNP and PTRAN. This report also describes the Carleton Laboratory for Radiotherapy Physics TG-43 Parameter Database, a publicly accessible web site (at http://www.physics.carleton.ca/clrp/seed&#95;database/) through which all of the data calculated for this study can be accessed. Also available on the web site are descriptions of the methods and Monte Carlo models used in this study and comparisons of data calculated in this study with data calculated by other authors.

It is now well recognized that natural products have directly or indirectly contributed to the discovery and development of as much as 75% of our current treatments for cancer and infectious disease as well as other indications. It cannot be overemphasized that new sources of chemical diversity are essential to the discovery of the next generation of chemotherapeutic agents. Characterization of the polyketide gene clusters responsible for the production of the spirangienes A and B provided detailed information regarding the biochemistry of myxobacterial secondary metabolism as well as significant insights into the evolution of post-PKS enzymes. The implications of these findings, coupled with additional examples, suggest that putative PKS products represent a new source of chemical diversity with chemotherapeutic potential and are thus worthy of further investigation.

The mechanisms by which agonists and other ligands bind ligand-gated ion channels are important determinants of function in neurotransmitter receptors. The partial agonist, kainic acid (KA) activates a less desensitized, and more robust AMPA receptor (AMPAR) current than full agonists, glutamate or AMPA. Cyclothiazide (CTZ), the allosteric modulator of AMPARs, potentiates receptor currents by inhibiting receptor desensitization resulting from agonist activation. We have constructed an AMPAR GluR1 subunit deletion mutant GluR1L3T(Delta739-784) by deleting the splice-variable "flip/flop" region of the L3 domain in the wild-type receptor and compared its function to that of the wild-type GluR1 receptor and an AMPAR substitution mutant GluR1A782N. When compared to GluR1, the potency of glutamate activation of GluR1L3T was increased, in contrast to a decrease in potency of activation and reduced sensitivity to optimal concentrations of KA. Furthermore, GluR1L3T was totally insensitive to CTZ potentiation of KA and glutamate-activated currents in Xenopus laevis oocytes. The potency of glutamate and KA activation of GluR1A782N was not significantly different from that of the wild-type GluR1 receptor although the mutant receptor currents were more sensitive to CTZ potentiation than the wild-type receptor current. This result is an indication that glutamate and KA binding to the agonist (S1/S2) domain on AMPAR can be modulated by an expendable splice-variable region of the receptor. Moreover, the effect of the allosteric modulator, CTZ on agonist activation of AMPAR can also be modified by a non-conserved amino acid residue substitution within the splice-variable "flip/flop" region.

Stereoselective synthesis of trans-2,6-disubstituted-3,4-dihydropyrans has been achieved from a simple homoallylic alkoxyether via a three-step sequence: electrophile-induced ether transfer, cyclization, and functionalization, which is highlighted by a rare example of Ferrier rearrangement of allylic ether. This methodology was successfully implemented for the asymmetric synthesis of a C7-C17 fragment of swinholide A.

Microtubules are significant therapeutic targets for the treatment of cancer, where suppression of microtubule dynamicity by drugs such as paclitaxel forms the basis of clinical efficacy. Peloruside A, a macrolide isolated from New Zealand marine sponge Mycale hentscheli, is a microtubule-stabilizing agent that synergizes with taxoid drugs through a unique site and is an attractive lead compound in the development of combination therapies. We report here unique allosteric properties of microtubule stabilization via peloruside A and present a structural model of the peloruside-binding site. Using a strategy involving comparative hydrogen-deuterium exchange mass spectrometry of different microtubule-stabilizing agents, we suggest that taxoid-site ligands epothilone A and docetaxel stabilize microtubules primarily through improved longitudinal interactions centered on the interdimer interface, with no observable contributions from lateral interactions between protofilaments. The mode by which peloruside A achieves microtubule stabilization also involves the interdimer interface, but includes contributions from the alpha/beta-tubulin intradimer interface and protofilament contacts, both in the form of destabilizations. Using data-directed molecular docking simulations, we propose that peloruside A binds within a pocket on the exterior of beta-tubulin at a previously unknown ligand site, rather than on alpha-tubulin as suggested in earlier studies.

Objective: Assays based on interferon gamma (IFNgamma) are an exciting new development for screening for latent tuberculosis infection (LTBI) in adults, but there are limited data on their effectiveness in children. Nevertheless new National Institute for Health and Clinical Excellence (NICE) guidelines recommend their use when screening paediatric tuberculosis (TB) contacts. We evaluated the potential effect of the new NICE guidelines on current paediatric practice., Design: Children screened for TB who had had an IFNgamma assay performed (QuantiFERON-TB Gold (QFG)) were included. Actual outcomes from existing guidelines were compared with those that would have been obtained using NICE guidelines., Results: QFG assays were performed on 120 children, 103 as part of TB contact tracing. Six of the 120 (5%) were QFG positive, and seven of the 120 (6%) were indeterminate. Where both Mantoux and QFG results were available, these agreed in 62/104 (60%) of cases. QFG tests were more likely to correlate with a negative Mantoux (98% agreement) than with a positive Mantoux (11% agreement). Management outcomes differed for 23/103 children seen as part of TB contact tracing. Only one (1%) of these had an indeterminate QFG result. 17 (85%) fewer children would have been given LTBI treatment (chemoprophylaxis) and two (2%) children with possible TB would not have been identified using NICE guidelines., Conclusion: New NICE guidelines for the use of IFNgamma-based tests for TB screening will reduce the number of children treated for presumed LTBI. Long-term prospective studies are needed to determine the number of children with positive Mantoux tests but negative IFNgamma results who are not given LTBI treatment yet later develop TB.

Aims: This study was undertaken to determine whether simultaneous administration of both alcohol and nicotine systemically would result in an additive dopamine release in the nucleus accumbens (NACC). Moreover, to also investigate whether nicotinic receptors may be mediating these effects of alcohol and nicotine, the effects of mecamylamine, a nicotinic receptor antagonist was also evaluated., Methods: Microdialysis was applied to measure the dopamine overflow in the shell region of NACC. All drugs were administered intraperitoneally. The doses of alcohol ranged from 0.5-2.0 g/kg, and nicotine and mecamylamine 0.25-1.0 mg/kg., Results: An additive effect of combined alcohol and nicotine on dopamine release was obtained. This effect of alcohol and nicotine was dose-dependently blocked by mecamylamine pre-treatment., Conclusions: These findings further support the hypothesis that an additive effect of alcohol and nicotine on the mesolimbic 'reward pathway' may contribute to the high incidence of smoking in alcoholics. Furthermore, nicotinic antagonists can block such effects of combined alcohol and nicotine.

Background: Despite synergistic increases in risks of various cancers, the incidence of concomitant smoking and drinking remains high. An additive or synergistic analgesic effect of combined alcohol and nicotine may contribute to their coabuse. Recently, we provided evidence that doses of alcohol and nicotine that are ineffective in inducing an antinociceptive effect alone, when combined, can induce such an effect. Moreover, this antinociceptive effect could be attenuated by pretreatment with the nonselective opioid antagonist naloxone. The purpose of this study was to determine the role of selective opioid receptor subtypes (micro, delta, and kappa) in mediating the antinociceptive effects of alcohol, nicotine, and their combination., Methods: Adult male Wistar rats were administered selective opioid antagonists, D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH(2) (CTAP, for micro receptor, 1.0 mg/kg), naltrindole (for delta receptors, 10 mg/kg), and norbinaltorphimine (nor-BNI, for kappa receptor, 10 mg/kg) before injection of alcohol, nicotine or their combination. The animals were tested in hot-plate and tail-flick assays, representing nociception mediated predominantly via brain or spinal pathways, respectively. All the injections were administered acutely and the nociceptive tests were carried out 20 minutes after alcohol and 10 minutes after nicotine administration., Results: In general, the antagonists were more effective in blocking the effects of alcohol, nicotine, or their combination in the tail-flick versus the hot-plate assay. CTAP was most effective in blocking the effects of alcohol alone and nicotine alone in the tail-flick test, whereas in the hot-plate test both CTAP and naltrindole were more effective than nor-BNI. All 3 antagonists had a very similar profile in attenuating the combination of alcohol and nicotine effect in the hot-plate assay. None of the antagonists had a significant effect against the highest alcohol-nicotine dose in this test. In the tail-flick test, however, CTAP and naltrindole were more effective than nor-BNI in attenuating the highest alcohol-nicotine dose., Conclusions: The data suggest the utility of all 3 opioid antagonists in blocking the effects of alcohol, nicotine, or their combination in spinally mediated antinociception. Although the supraspinally mediated antinociception was also attenuated by the opioid antagonists, further investigation of combination doses of these antagonists in fully blocking the supraspinal effects or attenuating voluntary alcohol and nicotine intake is warranted.

Salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline), a metabolite of dopamine, may act as an endogenous neurotoxin and contribute to the etiology of Parkinson's disease (PD). The inverse relationship between smoking and PD prompted our previous investigation and the report of protective effects of nicotine against salsolinol-induced toxicity in cultured SH-SY5Y cells (Copeland et al., Neurotox. Res. 8:289, 2005). These cells, derived from human neuroblastoma cells, express dopaminergic activity and are used as a model of nigral dopaminergic cells, the major site of pathology in PD. The purpose of the current study was to investigate whether apoptotic or antiapoptotic mechanisms were responsible for the observed effects of salsolinol and nicotine, respectively. Moreover, it was of interest to determine whether the actions of nicotine are mediated through nicotinic receptors. SH-SY5Y cells were exposed to 0.4 or 0.7 mM salsolinol with and without pretreatment in combination of 0.1 mM nicotine and 0.1 mM mecamylamine and were exposed for 24 and 48 h. Various parameters including cell cycle perturbations (reflected in propidium iodide DNA staining); cell cycle regulator retinoblastoma protein (reflected in the Western blot), apoptosis (reflected in annexin V/propidium iodide staining followed by flow cytometry) were analyzed. Salsolinol caused an arrest of the cells in G1-phase of cell cycle and an increase in apoptotic indices, whereas pretreatment with nicotine attenuated or completely blocked the effects of salsolinol. Nicotine effects in turn, were totally blocked by mecamylamine (0.1 mM). The results suggest that apoptosis is a major mechanism for salsolinol-induced toxicity and that antiapoptotic effects of nicotine, mediated by nicotinic receptors, may play a primary role in its neuroprotective effects. Hence, nicotinic agonists in combination with other antiapoptotic agents may be of substantial benefit in at least a subpopulation of Parkinson patients.

Complement is an important component of the innate and adaptive immune response, yet complement split products generated through activation of each of the three complement pathways (classical, alternative, and lectin) can cause inflammation and tissue destruction. Previous studies have shown that complement activation through the alternative, but not classical, pathway is required to initiate antibody-induced arthritis in mice, but it is unclear if the alternative pathway (AP) plays a role in established disease. Previously, we have shown that human complement receptor of the immunoglobulin superfamily (CRIg) is a selective inhibitor of the AP of complement. Here, we present the crystal structure of murine CRIg and, using mutants, provide evidence that the structural requirements for inhibition of the AP are conserved in human and mouse. A soluble form of CRIg reversed inflammation and bone loss in two experimental models of arthritis by inhibiting the AP of complement in the joint. Our data indicate that the AP of complement is not only required for disease induction, but also disease progression. The extracellular domain of CRIg thus provides a novel tool to study the effects of inhibiting the AP of complement in established disease and constitutes a promising therapeutic with selectivity for a single complement pathway.

Interstitial pneumonitis is a recognized complication following whole lung radiotherapy. We report two cases in which fatal pneumonitis appeared to be precipitated by the administration of epirubicin-containing combination chemotherapy within 7 weeks of completion of whole lung radiotherapy. These cases highlight a potentially fatal interaction between radiotherapy and modern chemotherapy regimens.

Three-dimensional covalent organic frameworks (3D COFs) were synthesized by targeting two nets based on triangular and tetrahedral nodes: ctn and bor. The respective 3D COFs were synthesized as crystalline solids by condensation reactions of tetrahedral tetra(4-dihydroxyborylphenyl) methane or tetra(4-dihydroxyborylphenyl)silane and by co-condensation of triangular 2,3,6,7,10,11-hexahydroxytriphenylene. Because these materials are entirely constructed from strong covalent bonds (C-C, C-O, C-B, and B-O), they have high thermal stabilities (400 degrees to 500 degrees C), and they also have high surface areas (3472 and 4210 square meters per gram for COF-102 and COF-103, respectively) and extremely low densities (0.17 grams per cubic centimeter).

[reaction: see text] 1,2-Disubstituted cyclopropanes were synthesized in a nonracemic fashion via activation of the corresponding homoallylic alcohols in excellent yields. A series of substituted phenyl rings showed higher enantiospecificity for the cyclization as the electron-withdrawing ability of the group increased. The results offer strong support for the existence of competing cation mechanisms.

Among the variants of medulloblastoma in the current WHO classification of nervous system tumors, the desmoplastic variant, which has been reported to constitute 5%-25% of pediatric medulloblastomas, is defined by its nodular collections of neurocytic cells bounded by desmoplastic internodular zones. We have studied the frequency, morphological features and biological behavior of medulloblastomas in two contemporaneous SIOP/UKCCSG trial cohorts of children with medulloblastomas, CNS9102 (n = 315) and CNS9204 (n = 35), focusing on tumors with nodular and desmoplastic phenotypes. In children aged 3-16 years (CNS9102), the nodular/desmoplastic medulloblastoma represented 5% of all tumors, while in infants aged <3 years (CNS9204) this variant represented 57% of medulloblastomas. Using iFISH to detect molecular cytogenetic abnormalities in medulloblastomas with a nodular architecture, we demonstrated distinct genetic profiles in desmoplastic and non-desmoplastic (classic and anaplastic) tumors; in particular, abnormalities of chromosome 17 occurred in the latter, but not the former. Significantly different outcomes were demonstrated for classic, nodular/desmoplastic and large cell/anaplastic medulloblastomas in both cohorts. In conclusion, the nodular/desmoplastic medulloblastoma appears to have clinical, genetic and biological characteristics that set it apart from other variants of this tumor.

In this study, BrachyDose, a recently developed EGSnrc Monte Carlo code for rapid brachytherapy dose calculations, has been benchmarked by reproducing previously published dosimetry parameters for three brachytherapy seeds with varied internal structure and encapsulation. Calculations are performed for two 125I seeds (Source Tech Medical Model STM1251 and Imagyn isoSTAR model 12501) and one l03Pd source (Theragenics Model 200). Voxel size effects were investigated with dose distribution calculations for three voxel sizes: 0.1 x 0.1 x 0.1 mm(3), 0.5 x 0.5 x 0.5 mm(3), and 1 X 1 X 1 mm(3). In order to minimize the impact of voxel size effects, tabulated dosimetry data for this study consist of a combination of the three calculations: 0.1 X 0.1 x 0.1 mm(3) voxels for distances in the range of 0

Objective: Emergency Departments (EDs) offer an opportunity to improve the care of patients with at-risk and dependent drinking by teaching staff to screen, perform brief intervention and refer to treatment (SBIRT). We describe here the implementation at 14 Academic EDs of a structured SBIRT curriculum to determine if this learning experience improves provider beliefs and practices., Methods: ED faculty, residents, nurses, physician extenders, social workers, and Emergency Medical Technicians (EMTs) were surveyed prior to participating in either a two hour interactive workshops with case simulations, or a web-based program (www.ed.bmc.org/sbirt). A pre-post repeated measures design assessed changes in provider beliefs and practices at three and 12 months post-exposure., Results: Among 402 ED providers, 74% reported < 10 hours of prior professional alcohol-related education and 78% had < 2 hours exposure in the previous year. At 3-month follow-up, scores for self-reported confidence in ability, responsibility to intervene, and actual utilization of SBIRT skills all improved significantly over baseline. Gains decreased somewhat at 12 months, but remained above baseline. Length of time in practice was positively associated with SBIRT utilization, controlling for gender, race and type of profession. Persistent barriers included time limitations and lack of referral resources., Conclusions: ED providers respond favorably to SBIRT. Changes in utilization were substantial at three months post-exposure to a standardized curriculum, but less apparent after 12 months. Booster sessions, trained assistants and infrastructure supports may be needed to sustain changes over the longer term.

[Structure: see text] A strategically novel approach to the formation of syn-1,3-diol mono- and diethers through electrophilic activation of homoallylic alkoxymethyl ethers has been developed. The resulting polyketide-like synthetic fragments are generated in good yield and with excellent stereocontrol. A chairlike transition state is proposed to account for the high stereoselectivity. Varying the conditions of the reaction workup results in the efficient generation of mono- and diether containing structural units common to polyketide natural products.

This review summarises current developments in radiation oncology and how they impact on the management of children with brain tumours. Improved understanding of radiobiology has led to attempts to improve the therapeutic ratio with hyperfractionated radiotherapy. Recent advances in planning and delivery of radiotherapy, including three-dimensional conformal radiotherapy, intensity modulated radiotherapy, and proton therapy allow a more precise localisation of the maximum dose region with maximum sparing of normal brain. Increasingly interactions between drugs and radiotherapy are exploited, but it is important to evaluate toxicity of combined modality therapy. The introduction of models to predict the impact of radiotherapy dose-volume parameters on long-term neuropsychological function will hopefully lead to further benefit with respect to sparing of normal tissue morbidity.

Although hypertension and alcohol dependence have been linked by epidemiological surveys and clinical observations, their interactive effects on brain function have rarely been tested. The present study involved the recording of P300 event related potentials (ERP) from 106 middle-aged African-American adults assigned to one of four groups: normotensive/nondependent (n=56), hypertensive/nondependent (n=11), normotensive/dependent (n=27), and hypertensive/dependent (n=12). The numbers of Nicotine Dependence, Major Depressive Disorder, and Conduct Disorder symptoms were specified as covariates within a 2 by 2 factorial design. ERPs were recorded during separate visual and auditory oddball tasks. The major result was a synergistic effect of hypertension and alcohol dependence on auditory P300 latency: the combination of both factors was associated with greater slowing than the sum of their independent effects. Future studies should continue to examine the potential synergistic effects of alcohol dependence and hypertension with a view toward identifying and reducing neurophysiological decrements and stroke risk among middle-aged patients.

Both alcohol and nicotine have been shown to possess antinociceptive or analgesic effects. An additive or synergistic antinociceptive effect induced by simultaneous administration of alcohol and nicotine could further contribute to their co-abuse. In this study, we sought to evaluate the antinociceptive effects of various combinations of ethanol and nicotine and to determine whether these effects could be blocked by an opioid antagonist. Adult male Wistar rats were treated with various doses of alcohol (0.1-2 g/kg), nicotine (0.01-2 mg/kg) or their combination and their behavior in tail flick test, reflective of spinal antinociception and hotplate test, mainly reflective of supraspinal antinociception were evaluated. Alcohol at the highest dose of 2 g/kg resulted in significant antinociceptive effects in both assays. Nicotine at 1 mg/kg resulted in significant antinociception in the hotplate; however, in the tail flick test a dose of 2 mg/kg was required for an antinociceptive effect. Combination of doses of alcohol and nicotine that were ineffective by themselves resulted in antinociceptive responses in both paradigms. These effects were attenuated by pretreatment with the non-selective opioid receptor antagonist naloxone. The data indicate that a combination of alcohol and nicotine can result in a synergistic antinociceptive response that is at least partially mediated by the opioid system. The analgesic effects induced by combination of alcohol and nicotine may be a contributory factor in their co-abuse.

The SIOP PNET 3 study was designed to determine whether 10 weeks of moderately intensive chemotherapy given after surgery and before radiotherapy (RT) would improve the outcome for patients with primitive neuroectodermal tumours (PNETs) compared with RT alone. Patients with a histological diagnosis of supratentorial PNET (StPNET) and no radiological evidence of metastatic disease were initially eligible for randomisation to either chemotherapy followed by craniospinal RT 35 Gy in 21 fractions with a boost of 20 Gy in 12 fractions to the primary site, or RT alone. In respect of the increasing recognition that StPNET were high-risk tumours, randomisation for this group closed in November 1999. This analysis includes both randomised and non-randomised patients with StPNET entered into the study database. Sixty-eight patients aged 2.9-16.6 years (median 6.5 years) were included in the analysis (chemotherapy+RT: 44, RT alone: 24). Fifty-four patients (79%) had a non-pineal and 14 (21%) a pineal site. At a median follow-up of 7.4 years, for all patients overall survival (OS) at 3 and 5 years was 54.4% and 48.3%, respectively. Event-free survival (EFS) at 3 and 5 years was 50.0% and 47.0%, respectively. There was no statistically significant difference in OS or EFS according to treatment received. OS (P=0.05) and EFS (P=0.03) were significantly better for patients with pineal primary sites. EFS for pineal tumours were 92.9% at 3 years and 71.4% at 5 years and for non-pineal primaries 40.7% at 3 years and 40.7% at 5 years. This study confirmed the relatively good survival for non-metastatic pineal PNETs but poor survival of non-pineal StPNETs. There was no evidence that pre-radiation chemotherapy improved outlook. Future treatment programs should be directed at the particular natural history of these tumours, to further define prognostic factors and to explore further biological characteristics.

Mucociliary transport can be assessed by monitoring the clearance rate of inhaled, dried, and crushed technetium-99m labeled sulfur colloid. A case is described of a patient who had a history of recurrent sinusitis, purulent sputum production, and infertility. It was thought he might have Kartagener syndrome, and his mucociliary clearance was shown to be abnormal.