Tyrosine Kinase Inhibitor Therapy for Brain Metastases in Non-Small-Cell Lung Cancer: A Primer for Radiologists

Treatment options for patients who develop brain metastases secondary to non-small-cell lung cancer have rapidly expanded in recent years. As a key adjunct to surgical and radiation therapy options, systemic therapies are now a critical component of the oncologic management of metastatic CNS disease in many patients with non-small-cell lung cancer. The aim of this review article was to provide a guide for radiologists, outlining the role of systemic therapies in metastatic non-small-cell lung cancer, with a focus on tyrosine kinase inhibitors. The critical role of the blood-brain barrier in the development of systemic therapies will be described. The final sections of this review will provide an overview of current imaging-based guidelines for therapy response. The utility of the Response Assessment in Neuro-Oncology criteria will be discussed, with a focus on how to use the response criteria in the assessment of patients treated with systemic and traditional therapies.

Nonneuroleptic Treatment of Disruptive Behavior in Organic Mental Syndromes

OBJECTIVE:

To summarize the literature describing nonneuroleptic treatments of unacceptably disruptive behavior in chronically institutionalized psychiatric patients with mental retardation, autism, organic brain syndrome, and dementia.

DATA SOURCES:

Relevant articles were identified from a MEDLINE search of the above diagnoses linked with “aggression” and “psychomotor agitation.” Additional references were found in the bibliographies of these articles.

STUDY SELECTION/DATA EXTRACTION:

The studies reviewed were limited to prospective evaluations of nonneuroleptic drug therapy of these behavior disturbances. Case reports, case series, and retrospective studies were excluded. Studies of patients with schizophrenia, affective disorders, and personality disorders were also excluded.

DATA SYNTHESIS:

Studies of lithium, beta-blockers, carbamazepine, benzodiazepines, and buspirone were adequate for review. As a rule, these studies are hampered by poor design. The lithium studies suggest that mentally retarded patients with behavior disturbances may respond to lithium treatment. The beta-blocker studies suggest improvement in patients with mental retardation, autism, organic brain syndrome, and dementia. Neuroleptic discontinuation or a decrease in dose was possible in some patients. The carbamazepine studies were inconclusive. Carbamazepine should be reserved for patients with concomitant seizure disorders. Benzodiazepines were helpful in treating elderly demented patients. Thus far, buspirone has been evaluated in only a few, poorly designed studies and is not yet recommended for treatment of behavior disturbances.

CONCLUSIONS:

Legislation has restricted the use of neuroleptics in many patients receiving long-term healthcare. Despite the questionable validity of the studies reviewed, lithium, beta-blockers, carbamazepine, and benzodiazepines may be considered as alternatives to neuroleptics in selected cases.

Pigment production and isotopic fractionations in continuous culture: okenone producing purple sulfur bacteria Part II

Okenone is a carotenoid pigment unique to certain members of Chromatiaceae, the dominant family of purple sulfur bacteria (PSB) found in euxinic photic zones. Diagenetic alteration of okenone produces okenane, the only recognized molecular fossil unique to PSB. The in vivo concentrations of okenone and bacteriochlorophyll a (Bchl a) on a per cell basis were monitored and quantified as a function of light intensity in continuous cultures of the purple sulfur bacterium Marichromatium purpuratum (Mpurp1591). We show that okenone-producing PSB have constant bacteriochlorophyll to carotenoid ratios in light-harvesting antenna complexes. The in vivo concentrations of Bchl a, 0.151 ± 0.012 fmol cell(-1), and okenone, 0.103 ± 0.012 fmol cell(-1), were not dependent on average light intensity (10-225 Lux) at both steady and non-steady states. This observation revealed that in autotrophic continuous cultures of Mpurp1591, there was a constant ratio for okenone to Bchl a of 1:1.5. Okenone was therefore constitutively produced in planktonic cultures of PSB, regardless of light intensity. This confirms the legitimacy of okenone as a signature for autotrophic planktonic PSB and by extrapolation water column euxinia. We measured the δ(13)C, δ(15)N, and δ(34)S bulk biomass values from cells collected daily and determined the isotopic fractionations of Mpurp1591. There was no statistical relationship in the bulk isotope measurements or stable isotope fractionations to light intensity or cell density under steady and non-steady-state conditions. The carbon isotope fractionation between okenone and Bchl a with respect to overall bulk biomass ((13)ε pigment - biomass) was 2.2 ± 0.4‰ and -4.1 ± 0.9‰, respectively. The carbon isotopic fractionation (13ε pigment-CO2) for the production of pigments in PSB is more variable than previously thought with our reported values for okenone at -15.5 ± 1.2‰ and -21.8 ± 1.7‰ for Bchl a.

Ecologically and geologically relevant isotope signatures of C, N, and S: okenone producing purple sulfur bacteria Part I

Purple sulfur bacteria (PSB) are known to couple the carbon, nitrogen, and sulfur cycling in euxinic environments. This is the first study with multiple strains and species of okenone-producing PSB to examine the carbon (C), nitrogen (N), and sulfur (S) metabolisms and isotopic signatures in controlled laboratory conditions, investigating what isotopic fractionations might be recorded in modern environments and the geologic record. PSB play an integral role in the ecology of euxinic environments and produce the unique molecular fossil okenane, derived from the diagenetic alteration of the carotenoid pigment okenone. Cultures of Marichromatium purpuratum 1591 (Mpurp1591) were observed to have carbon isotope fractionations ((13)ε biomass - CO2), via RuBisCO, ranging from -16.1 to -23.2‰ during exponential and stationary phases of growth. Cultures of Thiocapsa marina 5653 (Tmar5653) and Mpurp1591 had a nitrogen isotope fractionation ((15)ε biomass - NH 4) of -15‰, via glutamate dehydrogenase, measured and recorded for the first time in PSB. The δ(34) SVCDT values and amount of stored elemental sulfur for Mpurp1591 cells grown autotrophically and photoheterotrophically were dependent upon their carbon metabolic pathways. We show that PSB may contribute to the isotopic enrichments observed in modern and ancient anoxic basins. In a photoheterotrophic culture of Mpurp1591 that switched to autotrophy once the organic substrate was consumed, there were bulk biomass δ(13)C values that span a broader range than recorded across the Late Devonian, Permian-Triassic, Triassic-Jurassic, and OAE2 mass extinction boundaries. This finding stresses the complexities in interpreting and assigning δ(13)C values to bulk organic matter preserved in the geologic record.

Abstract P6-11-10: IBL2001: Phase I/II study of a novel dose-dense schedule of oral indibulin for the treatment of metastastic breast cancer

Background: Indibulin (ZI0-301) is a novel, oral, synthetic small molecule microtubule inhibitor which binds tubulin at a different site than taxanes and vinca alkaloids. Preclinical data demonstrate indibulin does not interact with acetylated (neuronal) tubulins and in clinical studies has not exhibited the neurotoxicity associated with other tubulin binders. Indibulin has potent antitumor activity in human cancer cell lines, including multidrug-, taxane-, and vinblastine-resistant. Norton-Simon modeling based on cell line data suggested that dose dense (dd) administration could optimize efficacy while limiting toxicity.

Methods: Eligible patients (pts) have metastatic or unresectable locally advanced breast cancer, ECOG performance status ≤ 2, adequate organ function, measurable or nonmeasurable disease and any number of prior therapies. Uncontrolled gastrointestinal malabsorption syndrome and grade 2 or higher peripheral neuropathy are the principal exclusions. Adverse events (AEs) are graded by CTCAE v. 4.0. Objective disease status is evaluated according to RECIST 1.1. The primary objective of the phase (Ph) I portion of the study is to determine the maximum tolerated dose (MTD) of indibulin when given in dd fashion 5 days treatment, 9 days rest using standard 3+3 dose escalation schema.

Peripheral neuritis in psittacine birds with proventricular dilatation disease

Necropsies were performed on 14 psittacine birds of various species suspected to have proventricular dilatation disease (PDD). Eight of the birds exhibited neurological signs (seizures, ataxia, tremors and uncoordinated movements) and digestive tract signs (crop stasis, regurgitation, inappetance and presence of undigested food in the faeces). At necropsy, the birds had pectoral muscle atrophy, proventricular and ventricular distention, thinning of the gizzard wall, and duodenal dilation. In addition, five birds had a transparent fluid (0.2 to 1.0 ml) in the subarachnoidal space of the brain, and one bird had dilatation of the right ventricle of the heart. The histological lesions differed from earlier reports of PDD in that peripheral (sciatic, brachial and vagal) neuritis was seen in addition to myenteric ganglioneuritis, myocarditis, adrenalitis, myelitis and encephalitis.

High resolution imaging of actin filaments in living cells under physilogically relevant conditions using apertureless near-field microscopy

Living cells were used to demonstrate the potential biological applications of the apertureless SNOM when operating under fluid. An oral epithelial squamous cell carcinoma cell line (H357) was imaged under physiological-like conditions using apertureless SNOM following staining with FITC-Phalloidin which preferentially stains intracellular actin filaments of the cytoskeleton. Compared with simultaneously obtained AFM topographic image, the apertureless SNOM data provides greater detail on these cellular structures and the spatial resolution of the apertureless SNOM fluorescence image appears to be about 100 nm.

Three-dimensional structures reveal multiple ADP/ATP binding modes for a synthetic class of artificial proteins

The creation of synthetic enzymes with predefined functions represents a major challenge in future synthetic biology applications. Here, we describe six structures of de novo proteins that have been determined using protein crystallography to address how simple enzymes perform catalysis. Three structures are of a protein, DX, selected for its stability and ability to tightly bind ATP. Despite the addition of ATP to the crystallization conditions, the presence of a bound but distorted ATP was found only under excess ATP conditions, with ADP being present under equimolar conditions or when crystallized for a prolonged period of time. A bound ADP cofactor was evident when Asp was substituted for Val at residue 65, but ATP in a linear configuration is present when Phe was substituted for Tyr at residue 43. These new structures complement previously determined structures of DX and the protein with the Phe 43 to Tyr substitution [Simmons, C. R., et al. (2009) ACS Chem. Biol. 4, 649-658] and together demonstrate the multiple ADP/ATP binding modes from which a model emerges in which the DX protein binds ATP in a configuration that represents a transitional state for the catalysis of ATP to ADP through a slow, metal-free reaction capable of multiple turnovers. This unusual observation suggests that design-free methods can be used to generate novel protein scaffolds that are tailor-made for catalysis.

Gamma-ray emission concurrent with the nova in the symbiotic binary V407 Cygni

Novae are thermonuclear explosions on a white dwarf surface fueled by mass accreted from a companion star. Current physical models posit that shocked expanding gas from the nova shell can produce x-ray emission, but emission at higher energies has not been widely expected. Here, we report the Fermi Large Area Telescope detection of variable gamma-ray emission (0.1 to 10 billion electron volts) from the recently detected optical nova of the symbiotic star V407 Cygni. We propose that the material of the nova shell interacts with the dense ambient medium of the red giant primary and that particles can be accelerated effectively to produce pi(0) decay gamma-rays from proton-proton interactions. Emission involving inverse Compton scattering of the red giant radiation is also considered and is not ruled out.

Spectrum of the isotropic diffuse gamma-ray emission derived from first-year Fermi Large Area Telescope data

We report on the first Fermi Large Area Telescope (LAT) measurements of the so-called "extragalactic" diffuse gamma-ray emission (EGB). This component of the diffuse gamma-ray emission is generally considered to have an isotropic or nearly isotropic distribution on the sky with diverse contributions discussed in the literature. The derivation of the EGB is based on detailed modeling of the bright foreground diffuse Galactic gamma-ray emission, the detected LAT sources, and the solar gamma-ray emission. We find the spectrum of the EGB is consistent with a power law with a differential spectral index gamma = 2.41 +/- 0.05 and intensity I(>100 MeV) = (1.03 +/- 0.17) x 10(-5) cm(-2) s(-1) sr(-1), where the error is systematics dominated. Our EGB spectrum is featureless, less intense, and softer than that derived from EGRET data.

Fermi large area telescope search for photon lines from 30 to 200 GeV and dark matter implications

Dark matter (DM) particle annihilation or decay can produce monochromatic gamma rays readily distinguishable from astrophysical sources. gamma-ray line limits from 30 to 200 GeV obtained from 11 months of Fermi Large Area Space Telescope data from 20-300 GeV are presented using a selection based on requirements for a gamma-ray line analysis, and integrated over most of the sky. We obtain gamma-ray line flux upper limits in the range 0.6-4.5x10{-9} cm{-2} s{-1}, and give corresponding DM annihilation cross-section and decay lifetime limits. Theoretical implications are briefly discussed.

The use of C(av) rather than AUC in safety assessment

Toxicokinetic data have traditionally been presented as maximum observed plasma concentrations (C(max)) and area under the concentration time curve (AUC) values. These values have been used to compare exposures across studies and species to provide valuable interpretation of drug safety data. Increasingly, questions are asked of toxicology studies to more accurately describe the concentration effect relationships in terms of compound affinity for target and off-target receptors. C(max) values can immediately be referenced to known pharmacological activities, particularly when the extent of plasma protein binding is taken into account. This provides a measure of the more pharmacologically relevant free drug exposure. AUC values on the other hand contain the component of time, which means that direct comparison to pharmacological activity values are not immediately possible. Conversion of AUC to average plasma concentration (C(av)) provides a simple and convenient means to allow such a comparison without losing any information imparted by AUC values. In this paper, the benefit and advantage of applying C(av) values is illustrated using examples taken from the literature.

Anti-interleukin-5 antibody treatment (mepolizumab) in active eosinophilic oesophagitis: a randomised, placebo-controlled, double-blind trial

OBJECTIVE

Eosinophilic oesophagitis (EoO) is a clinicopathological condition defined by proton pump inhibitor-refractory oesophageal symptoms combined with oesophageal eosinophilia. The pharmacodynamic effect of mepolizumab (a humanised anti-interleukin-5 monoclonal antibody) in EoO was evaluated.

METHODS

Eleven adults with active EoO (>20 peak eosinophil number/high power field (hpf) and dysphagia) were randomised to 750 mg of mepolizumab (n = 5) or placebo (n = 6) and received two intravenous infusions, 1 week apart. Those not in complete remission (<5 peak eosinophil number/hpf) after 8 weeks received two further doses 4 weeks apart, 1500 mg of mepolizumab or placebo. The effect of mepolizumab was assessed clinically, endoscopically, histologically, and via blood and tissue biomarkers.

RESULTS

As assessed by immunofluorescence, a marked reduction of mean oesophageal eosinophilia (p = 0.03) was seen in the mepolizumab group (-54%) compared with the placebo group (-5%) 4 weeks after initiation of treatment. No further reduction of eosinophil numbers was observed in response to the two additional infusions in either group. Mepolizumab reduced tenascin C (p = 0.033) and transforming growth factor beta1 (p = 0.05) expression in the oesophageal epithelial layer 13 weeks after initiation of treatment. Clinically, limited improvement of symptoms was seen, although a trend was seen between 4 and 13 weeks after initiation of mepolizumab treatment. Mepolizumab was well tolerated.

CONCLUSIONS

Mepolizumab significantly reduced eosinophil numbers in oesophageal tissues in adult patients with active EoO, and changes in the expression of molecules associated with oesophageal remodelling were reversed. Minimal clinical improvement was achieved in a subgroup of patients with EoO. Mepolizumab had an acceptable safety profile, even at the high 1500 mg dose level.

TRIAL REGISTRATION NUMBER

NCT00274703.

Fermi large area telescope measurements of the diffuse gamma-ray emission at intermediate galactic latitudes

The diffuse galactic gamma-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess gamma-ray emission greater, > or approximately equal to 1 GeV relative to diffuse galactic gamma-ray emission models consistent with directly measured CR spectra (the so-called "EGRET GeV excess"). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse gamma-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV and galactic latitudes 10 degrees < or = |b| < or = 20 degrees. The LAT spectrum for this region of the sky is well reproduced by a diffuse galactic gamma-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.

Detection of high-energy gamma-ray emission from the globular cluster 47 Tucanae with Fermi

We report the detection of gamma-ray emissions above 200 megaelectron volts at a significance level of 17sigma from the globular cluster 47 Tucanae, using data obtained with the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. Globular clusters are expected to emit gamma rays because of the large populations of millisecond pulsars that they contain. The spectral shape of 47 Tucanae is consistent with gamma-ray emission from a population of millisecond pulsars. The observed gamma-ray luminosity implies an upper limit of 60 millisecond pulsars present in 47 Tucanae.

Detection of 16 gamma-ray pulsars through blind frequency searches using the Fermi LAT

Pulsars are rapidly rotating, highly magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there are more than 1800 known radio pulsars, until recently only seven were observed to pulse in gamma rays, and these were all discovered at other wavelengths. The Fermi Large Area Telescope (LAT) makes it possible to pinpoint neutron stars through their gamma-ray pulsations. We report the detection of 16 gamma-ray pulsars in blind frequency searches using the LAT. Most of these pulsars are coincident with previously unidentified gamma-ray sources, and many are associated with supernova remnants. Direct detection of gamma-ray pulsars enables studies of emission mechanisms, population statistics, and the energetics of pulsar wind nebulae and supernova remnants.

Measurement of the cosmic ray e+ +e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope

Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with a large acceptance exceeding 2 m;{2} sr at 300 GeV. Building on the gamma-ray analysis, we have developed an efficient electron detection strategy which provides sufficient background rejection for measurement of the steeply falling electron spectrum up to 1 TeV. Our high precision data show that the electron spectrum falls with energy as E-3.0 and does not exhibit prominent spectral features. Interpretations in terms of a conventional diffusive model as well as a potential local extra component are briefly discussed.

High-dose chemotherapy with autologous stem-cell support versus standard-dose chemotherapy: meta-analysis of individual patient data from 6 randomized metastatic breast cancer trials

Abstract #6113

Background: The role of high-dose chemotherapy (HDC) with autologous hematopoietic stem-cell transplantation for metastatic breast cancer has not been well defined. The statistical power of the available trials has limited precision for determining whether HDC has any benefit for this indication, or for any subset of patients.&#x2028; Methods: Individual patient data from the 6 known randomized trials were merged into a single database. The primary endpoint was overall survival (OS): time from randomization to death. The secondary endpoint was progression-free survival (PFS). Cox proportional hazards regression compared the effect of HDC vs standard-dose chemotherapy (SDC) on PFS and OS adjusted for age, trial and hormone receptor (HmR) status (positive if either estrogen (ER) or progesterone (PgR) receptor positive), and other variables. Among the subset analyses considered were by age, HmR status, number metastatic sites, and soft tissue metastases.&#x2028; Results: A total of 846 patients (433 HDC, 413 SDC) had median follow-up of 1.9 years. Median age was 47 years (range 23 to 65). Preliminary analyses show that after adjusting for age and trial, HDC significantly prolonged OS (hazard ratio (HR) 0.86; 95%CI 0.73-1.00; p=0.05) and PFS (HR 0.73; 95%CI 0.63-0.84; p&lt;0.0001). Mean improvement (out to 8 yrs) was 4 months for both OS and PFS. Both age (p=0.023) and soft tissue disease (p=0.0025) had statistically significant interactions with treatment for OS, but neither remain significant after adjusting for multiple comparisons.&#x2028; Conclusions: HDC may have a modest benefit on OS that may be greater in patients younger than 50 years. However, we were not able to draw firm conclusions about age or other subset analyses.&#x2028; &#x2028;

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6113.

A new atomic force microscope force ramp technique using digital force feedback control reveals mechanically weak protein unfolding events

We have developed a new force ramp modification of the atomic force microscope (AFM) which can control multiple unfolding events of a multi-modular protein using software-based digital force feedback control. With this feedback the force loading rate can be kept constant regardless the length of soft elastic linkage or number of unfolded polypeptide domains. An unfolding event is detected as a sudden drop in force, immediately after which the feedback control reduces the applied force to a low value of a few pN by lowering the force set point. Hence the remaining folded domains can relax and the subsequent force ramp is applied to relaxed protein domains identically in each case. We have applied this technique to determine the kinetic parameters x(u), which is the distance between the native state and transition state, and α(0), which is the unfolding rate constant at zero force, for the mechanical unfolding of a pentamer of I27 domains of titin. In each force ramp the unfolding probability depends on the number of folded domains remaining in the system and we had to take account of this effect in the analysis of unfolding force data. We obtained values of x(u) and α(0) to be 0.28 nm and 1.02 × 10(-3) s(-1), which are in good agreement with those obtained from conventional constant velocity experiments. This method reveals unfolding data at low forces that are not seen in constant velocity experiments and corrects for the change in stiffness that occurs with most mechanical systems throughout the unfolding process to allow constant force ramp experiments to be carried out. In addition, a mechanically weak structure was detected, which formed from the fully extended polypeptide chain during a force quench. This indicates that the new technique will allow studies of the folding kinetics of previously hidden, mechanically weak species.

The Fermi Gamma-Ray Space Telescope discovers the pulsar in the young galactic supernova remnant CTA 1

Energetic young pulsars and expanding blast waves [supernova remnants (SNRs)] are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 milliseconds and a period derivative of 3.614 x 10(-13) seconds per second. Its characteristic age of 10(4) years is comparable to that estimated for the SNR. We speculate that most unidentified Galactic gamma-ray sources associated with star-forming regions and SNRs are such young pulsars.

Towards a unified theory of muscle contraction. I: foundations

Molecular models of contractility in striated muscle require an integrated description of the action of myosin motors, firstly in the filament lattice of the half-sarcomere. Existing models do not adequately reflect the biochemistry of the myosin motor and its sarcomeric environment. The biochemical actin-myosin-ATP cycle is reviewed, and we propose a model cycle with two 4- to 5-nm working strokes, where phosphate is released slowly after the first stroke. A smaller third stroke is associated with ATP-induced detachment from actin. A comprehensive model is defined by applying such a cycle to all myosin-S1 heads in the half-sarcomere, subject to generic constraints as follows: (a) all strain-dependent kinetics required for actin-myosin interactions are derived from reaction-energy landscapes and applied to dimeric myosin, (b) actin-myosin interactions in the half-sarcomere are controlled by matching rules derived from the structure of the filaments, so that each dimer may be associated with a target zone of three actin sites, and (c) the myosin and actin filaments are treated as elastically extensible. Numerical predictions for such a model are presented in the following paper.

A phase I and pharmacokinetic study of lapatinib in combination with infusional 5-fluorouracil, leucovorin and irinotecan

BACKGROUND

This study determined the optimally tolerated regimen (OTR) of oral lapatinib administered in combination with infusional 5-fluorouracil (5-FU), leucovorin and irinotecan (FOLFIRI) and assessed the safety, tolerability and pharmacokinetics of the combination.

PATIENTS AND METHODS

Twenty-five patients were enrolled; 12 patients were treated at three dose levels to determine OTR; then 13 patients were treated at OTR to evaluate the pharmacokinetics of the combination.

RESULTS

The 2-weekly OTR comprised lapatinib 1250 mg/day with irinotecan 108 mg/m(2) (day 1) and leucovorin 200 mg/m(2), 5-FU bolus 240 mg/m(2) and 5-FU infusion 360 mg/m(2) (days 1 and 2); doses of 5-FU and irinotecan represent a 40% reduction in dose compared to conventional FOLFIRI. Dose-limiting toxicities were grade 3 diarrhoea and grade 4 neutropenia. Co-administration of lapatinib increased the area under the plasma concentration-time curve of SN-38, the active metabolite of irinotecan, by an average of 41%; no other pharmacokinetic interactions were observed. Of 19 patients evaluable for disease response assessment, four patients had partial response and nine patients had stable disease.

CONCLUSION

The combination of lapatinib and FOLFIRI is safe and demonstrates clinical activity; the documented PK interaction can effectively be compensated by lowering the doses of 5-FU and irinotecan. This regime may be further tested in a phase II trial.

A nanoscale three-dimensional Monte Carlo simulation of electron-beam-induced deposition with gas dynamics

A computer simulation was developed to simulate electron-beam-induced deposition (EBID). Simulated growth produced high-aspect-ratio, nanoscale pillar structures by simulating a stationary Gaussian electron beam. The simulator stores in memory the spatial and temporal coordinates of deposited atoms in addition to the type of electron, either primary (PE), back-scattered (BSE), or secondary (SE), that induced its deposition. The results provided in this paper apply to tungsten pillar growth by EBID on a tungsten substrate from WF(6) precursor, although the simulation may be applied to any substrate-precursor set. The details of the simulation are described including the Monte Carlo electron-solid interaction simulation used to generate scattered electron trajectories and SE generation, the probability of molecular dissociation of the precursor gas when an electron traverses the surface, and the gas dynamics which control the surface coverage of the WF(6) precursor on the substrate and pillar surface. In this paper, three specific studies are compared: the effects of beam energy, mass transport versus reaction-rate-limited growth, and the effects of surface diffusion on the EBID process.

Statin therapy for native and peri-interventional coronary heart disease

Atherosclerosis is a slow, complex process involving many different cell types and their interactions producing excessive oxidant stress, increased inflammation, abnormal endothelium-dependent vasodilation, and localized increases in thrombogenic and decreases in fibrinolytic factors. Numerous factors incite these processes, but oxidized LDL particles seem the most essential component of this pathologic cascade. These oxidized particles set up a chain of biochemical events eventually leading to clinical atherosclerotic events. Statins have been shown to reduce such events by 40 to 50% when LDL cholesterol is lowered to less than 80 mg/dL. But in-vitro studies have shown that the provision of mevalonate, not cholesterol, can result in reversal of some of the beneficial effects of statins, suggesting that other mechanisms such as inhibiting the formation of the isoprenoids, farnesyl pyrophosphate and geranylgeranyl pyrophosphate, and thus prenylation of many cell-signaling proteins may be important in the preventive effects of statins. Clinically, these more rapid, non-lipid-altering effects may be more apparent in acute coronary syndromes. Now that we have more LDL-cholesterol lowering agents which lower LDL-cholesterol without blocking HMG CoA reductase, we may be better able to dissect and understand the importance of these non-lipid-altering effects of statins in human disease.

Detection of Chlamydia pneumoniae in atherosclerotic tissue: a comparative study of PCR and immunocytochemistry

The reported prevalence of Chlamydia pneumoniae in atherosclerotic tissue appears to depend on the detection system used. This introduces problems in determining the role of C. pneumoniae in atherosclerosis. This study analyses the sensitivity and performance of molecular diagnostic methods for the detection of C. pneumoniae and polymerase chain reaction (PCR) inhibitors in atheromatous tissue. Atherosclerotic tissue taken from 30 coronary endarterectomies, nine coronary arteries from explanted hearts, 16 carotid and two femoral endarterectomies are studied. Nested PCR (nPCR) assays targeting the PstI restriction fragment, the OmpA gene and the CRP operon of the chlamydial genome and immunocytochemistry (ICC) are used. Internal controls (IC) are constructed to co-amplify with the specific amplicons and identify the presence of inhibitor. The OmpA, PstI and CRP operon PCR assays had similar analytical sensitivities. However, the OmpA PCR was most affected by PCR inhibitors. Despite this, eight samples (14%) tested positive in the OmpA nPCR and no positives were found using the PstI or CRP operon nPCRs. Primary isolates of C. pneumoniae obtained from 12 patients with acute respiratory infection were positive in all three assays. Of the 48 specimens available for ICC, 33 (69%) were positive for chlamydial antigens. These included samples found positive by PCR. Dilution of samples to eliminate PCR inhibitors may have contributed to the discordant ICC and PCR results. The OmpA PCR, when used with an IC to identify samples with PCR inhibitors, is a reliable tool. However, the sensitivity of the ICC methods justifies their continued use.

Assessing reliability of microsatellite genotypes from kit fox faecal samples using genetic and GIS analyses

Noninvasive faecal DNA sampling has the potential to provide a wealth of information necessary for monitoring and managing endangered species while eliminating the need to capture, handle or observe rare individuals. However, scoring problems, and subsequent genotyping errors, associated with this monitoring method remain a great concern as they can lead to misidentification of individuals and biased estimates. We examined a kit fox scat data set (353 scats; 80 genotypes) for genotyping errors using both genetic and GIS analyses, and evaluated the feasibility of combining both approaches to assess reliability of the faecal DNA results. We further checked the appropriateness of using faecal genotypes to study kit fox populations by describing information about foxes that we could deduce from the 'acceptable' scat genotypes, and comparing it to information gathered with traditional field techniques. Overall, genetic tests indicated that our data set had a low rate of genotyping error. Furthermore, examination of distributions of scat locations confirmed our data set was relatively error free. We found that analysing information on sex primer consistency and scat locations provided a useful assessment of scat genotype error, and greatly limited the amount of additional laboratory work that was needed to identify potentially 'false' scores. 'Acceptable' scat genotypes revealed information on sex ratio, relatedness, fox movement patterns, latrine use, and size of home range. Results from genetic and field data were consistent, supporting the conclusion that our data set had a very low rate of genotyping error and that this noninvasive method is a reliable approach for monitoring kit foxes.

Abdominal diameter index: a more powerful anthropometric measure for prevalent coronary heart disease risk in adult males

AIM

The authors wished to compare the strength of association of several anthropometric measures of body size and fat distribution among themselves and in comparison with other known risk factors for prevalent coronary heart disease (CHD).

METHODS

Prevalent CHD was assessed in 466 middle-aged, male, multiracial Triborough Bridge and Tunnel Authority officers in New York City by verified history, electrocardiogram or exercise stress test. Anthropometric measures included body mass index, waist, hip and thigh circumferences, waist-hip ratio, waist-thigh ratio, sagittal abdominal diameter and abdominal diameter index (sagittal abdominal diameter/thigh circumference). Results were compared with other CHD risk factors measured simultaneously (history of diabetes, smoking, blood pressure, lipid profile, apolipoproteins A and B, lipoprotein (a), homocysteine, fibrinogen, urinary microalbumin, serum vitamin E and ferritin) and a calculated 10-year CHD risk using a Framingham algorithm (10-year Framingham CHD risk).

RESULTS

CHD was found in 29 individuals. Of the six anthropometric measures, abdominal diameter index gave the largest and most significant standardized odds ratio (OR) for CHD [1.80, 95% confidence interval (CI) 1.20, 2.71], equivalent to 10-year Framingham CHD risk. Men in the highest compared with the lowest tertile of abdominal diameter index had a univariate OR of 5.47 (95% CI 1.55, 19.28) which was the only anthropometric measure that remained significant after adjusting for 10-year Framingham CHD risk.

CONCLUSIONS

For middle-aged American men, abdominal diameter index may be the most powerful anthropometric measure of risk for prevalent CHD.

Time course toxicogenomic profiles in CD-1 mice after nontoxic and nonlethal hepatotoxic paracetamol administration

Adverse drug reactions are a major clinical problem. Drug-induced hepatotoxicity constitutes a large percentage of these reactions. A thorough understanding of the genetic events, specifically, the early "decision-making" processes underlying biological changes caused by drugs and metabolites, is required. To assist in the understanding of these events, we have employed the model hepatotoxin, paracetamol (APAP), and GeneChip technology to investigate global genetic events seen after nontoxic and toxic doses in the mouse. Mice were dosed [vehicle, nontoxic APAP (1 mmol/kg), and toxic APAP (3.5 mmol/kg)], and individual hepatic RNA samples were hybridized to separate chips to determine interanimal variation. Statistical analysis detected 175 CD-1 mouse genes that were significantly regulated (P < 4.1 x 10(-6)), and nonsignificant genes were discarded. For clarity, the significantly regulated genes were then binned into categories according to their major function-antioxidant, glutathione, metabolism, transcription, immune, and apoptosis. There was no hepatic stress observed after dosing 1 mmol/kg APAP, when measured by serum alanine aminotransferase levels. Hepatic toxicity was observed at both 4 and 24 h after a 3.5 mmol/kg dose of APAP. Time course expression profiles for selected genes have been created. These results demonstrate that most active gene expression occurs around 4 h after a toxic dose of APAP. Down-regulation of these genes is observed over 24 h, coinciding with the development of overt toxicity. These data provide a deeper understanding of the in vivo time course of physiological responses of the liver to chemical stress and provide a logical step forward for the investigation of new chemical entities demonstrated positive in chemically reactive metabolite screens. The complete data set can be viewed at http://www.ebi.ac.uk/arrayexpress/. The accession number is E-MEXP-82.

Matrix metalloproteinase-9 expression is associated with the presence of Chlamydia pneumoniae in human coronary atherosclerotic plaques

OBJECTIVE

To investigate the association between Chlamydia pneumoniae and matrix metalloproteinase-9 (MMP-9) in atherosclerotic plaques.

DESIGN

31 coronary atherosclerotic plaque specimens were studied by immunohistochemistry, polymerase chain reaction (PCR), and reverse transcription PCR for the presence of C pneumoniae antigen and genomic DNA, and of MMP-9 protein and transcripts.

RESULTS

Immunohistochemical analysis identified a strong association between the presence of C pneumoniae antigen and production of MMP-9 in coronary atherosclerotic plaques (p = 0.001). Furthermore, analysis of the intralesional amount of C pneumoniae and MMP-9 indicated an increased number of cells positive for MMP-9 in arterial sections that had increased C pneumoniae positivity (p < 0.05).

CONCLUSIONS

This study provides evidence of an association between expression of MMP-9 and the intravascular presence of C pneumoniae and may suggest a potential pathological mechanism whereby C pneumoniae may contribute to the progression of coronary atherosclerosis.

Isolation, identification, and selection of lactic acid bacteria from alfalfa sprouts for competitive inhibition of foodborne pathogens

Several studies have investigated the control of pathogens on alfalfa sprouts, and some treatments have been shown to be effective in reducing pathogen populations. However, control methods investigated thus far only provide pathogen control at a given point in the sprouting process and can affect germination. Competitive inhibition of pathogens with lactic acid bacteria might provide pathogen control throughout the sprouting process and up to consumption. The purpose of this study was to isolate and identify lactic acid bacteria from alfalfa sprouts to inhibit the growth of foodborne pathogens. Fifty-eight lactic acid bacteria isolates were obtained from alfalfa seeds and sprouts. These isolates were evaluated for inhibitory action against Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes by agar spot tests. All pathogens were inhibited by 32 (55%) of the isolates, S. enterica by 56 (97%), E. coli O157:H7 by 49 (84%), and L. monocytogenes by 41 (71%). The isolates were identified by the Analytical Profile Index evaluation of carbohydrate utilization. Isolates obtained from a sample of alfalfa seeds and identified as Lactococcus lactis subsp. lactis showed zones of inhibition of 4.0 mm or greater for all pathogens. One of these isolates, Lactococcus lactis subsp. lactis (L7), and an isolate previously obtained, Pediococcus acidilactici (D3), were evaluated for competitive inhibition of S. enterica, E. coli O157:H7, and L. monocytogenes in deMan Rogosa Sharpe agar and broth. Pathogen populations were significantly reduced by day 5. The selected isolates will be further evaluated in future studies for inhibitory action toward S. enterica, E. coli O157:H7, and L. monocytogenes during sprouting.

Preservation of post-transplant lung function with aerosol cyclosporin

Post-lung transplant use of aerosol cyclosporin (ACsA) is considered by examining the relationship between deposited aerosol dose and effect. In a sub-study of placebo controlled trials of ACsA as a rejection prophylaxis, 15 drug subjects received aerosol dose quantification tests to gage their ability to effectively deposit the nebulised drug in their transplanted lung(s). A total of seven placebo subjects received mock deposition tests. The deposited doses and mock doses were compared to changes in the forced expiratory volume in one second, at six time points during the 2-yr trial period (ACsA was started within 6 weeks post-transplant). Linear relationships were demonstrated between deposited dose and improvement in lung function in the drug subjects at all intervals. Mock dose data from placebo subjects did not demonstrate similar correlation. Based on these results, subjects were grouped by dose and compared. Subjects depositing > or = 5 mg of the drug in the periphery of their transplant(s) had improving pulmonary function on average. Low-dose and placebo subjects demonstrated declines, more A2-A4 rejection events in the latter portion of the trial, and more chronic rejection beyond the end of the trial. A dose-to-effect relationship is demonstrated for aerosol cyclosporin in terms of pulmonary function and biopsy proven rejection.

Aerosol cyclosporin therapy in lung transplant recipients with bronchiolitis obliterans

The majority of patients who develop bronchiolitis obliterans, after lung transplantation, die within 2-3 yrs after onset since treatment with conventional immunosuppression is typically ineffective. A case/control study was conducted in lung transplant recipients with biopsy-documented bronchiolitis obliterans to determine whether aerosol cyclosporin use contributed to increased survival. The cases comprised 39 transplant recipients who received open-label aerosol cyclosporin treatment in addition to conventional immunosuppression. The controls were transplant recipients treated with conventional immunosuppression alone. There were 51 controls from the University of Pittsburgh Medical Center and 100 from a large multicentric database (Novartis Lung Transplant Database). Forced expiratory volume in one second expressed as a percentage of the predicted value was an independent predictor of survival in all patients with bronchiolitis obliterans. Cox proportional-hazards analysis revealed a survival advantage for aerosol cyclosporin cases compared to the Pittsburgh control group. A survival advantage was also seen when comparing study cases to multicentric controls. Aerosol cyclosporin, given with conventional immunosuppression to lung transplant recipients with bronchiolitis obliterans, provides a survival advantage over conventional therapy alone.

Apertureless near-field Raman spectroscopy

We report on the tip-enhanced Raman spectra of C60 obtained on a custom-built apertureless scanning near-field optical microscope. A commercial atomic force microscope tip coated with 100 nm thickness of gold was used to enhance locally the Raman signal and permit topographic and spectral information to be acquired simultaneously. We present preliminary data which demonstrate the tip enhancement effect using C60 as a test sample.

The disposition of voriconazole in mouse, rat, rabbit, guinea pig, dog, and human

Voriconazole is a new triazole antifungal agent with potent, wide-spectrum activity. Its pharmacokinetics and metabolism have been studied in mouse, rat, rabbit, dog, guinea pig, and humans after single and multiple administration by both oral and intravenous routes. Absorption of voriconazole is essentially complete in all species. The elimination of voriconazole is characterized by non-linear pharmacokinetics in all species. Consequently, pharmacokinetic parameters are dependent upon dose, and a superproportional increase in area under the curve is seen with increasing dose in rat and dog toxicology studies. Following multiple administration, there is a decrease in systemic exposure. This is most pronounced in mouse and rat, less so in dog, and not observed in guinea pig or rabbit. Repeat-dose toxicology studies in mouse, rat, and dog have demonstrated that induction of cytochrome P450 by voriconazole (autoinduction of metabolism) is responsible for the decreased exposure in these species. Autoinduction of metabolism is not observed in humans, and plasma steady-state concentrations remain constant with time. Voriconazole is extensively metabolized in all species. The major pathways in humans involve fluoropyrimidine N-oxidation, fluoropyrimidine hydroxylation, and methyl hydroxylation. Also, N-oxidation facilitates cleavage of the molecule, resulting in loss of the fluoropyrimidine moiety and subsequent conjugation with glucuronic acid. Major pathways are represented in animal species. The major circulating metabolite in rat, dog, and human is the N-oxide of voriconazole. It is not thought to contribute to efficacy since it is at least 100-fold less potent than voriconazole against fungal pathogens in vitro.

Cooperative regulation of myosin-actin interactions by a continuous flexible chain II: actin-tropomyosin-troponin and regulation by calcium

The model of myosin regulation by a continuous tropomyosin chain is generalized to a chain of tropomyosin-troponin units. Myosin binding to regulated actin is cooperative and initially inhibited by the chain as before. In the absence of calcium, myosin is further inhibited by the binding of troponin-I to actin, which through the whole of troponin pins the tropomyosin chain in a blocking position; myosin and TnI compete for actin and induce oppositely-directed chain kinks. The model predicts equilibrium binding curves for myosin-S1 and TnI as a function of their first-order affinities K(S1) and L(TI). Myosin is detached by the actin binding of TnI, but TnI is more efficiently detached by myosin when the kink size (typically nine to ten actin sites) spans the seven-site spacing between adjacent TnI molecules. An allosteric mechanism is used for coupling the detachment of TnI to calcium binding by TnC. With thermally activated TnI kinks (kink energy B approximately k(B)T), TnI also binds cooperatively to actin, producing cooperative detachment of myosin and biphasic myosin-calcium Hill plots, with Hill coefficients of 2 at high calcium and 4-6 at low calcium as observed in striated muscle. The theory also predicts the cooperative effects observed in the calcium loading of TnC.

Identification of the cytochrome P450 enzymes involved in the N-oxidation of voriconazole

Voriconazole is a triazole antifungal agent with potent activity against a broad spectrum of clinically significant pathogens. In vivo and in vitro studies have demonstrated that voriconazole is extensively metabolized, with the major circulating metabolite resulting from N-oxidation. In the present study, we report on the human cytochrome P450 enzymes responsible for the generation of this metabolite. In human liver microsomes voriconazole N-oxidation exhibited biphasic kinetics with K(m1) of 8.1 microM, and K(m2) of 835 microM. Studies at 2500 microM voriconazole identified CYP3A4 as the low-affinity component, with activity correlating strongly with CYP3A4 activity in a bank of human liver microsomes (r = 0.90) and inhibited by ketoconazole. At 25 microM, voriconazole N-oxidation showed strong correlation with CYP2C19 and CYP3A4 activity (r = 0.77 and 0.74, respectively) and was inhibited by both sulfaphenazole and ketoconazole. Incubations with recombinant enzymes suggested both CYP2C9 and CYP2C19 as high-affinity enzymes (K(m) values of 20 and 3.5 microM, respectively). Further studies used chemical inhibitors in human liver microsomes prepared from individual donors, including two CYP2C19 poor metabolizers. No inhibition was observed with sulfaphenazole, indicating a minor role for CYP2C9 in human liver, but inhibition by ketoconazole was most potent in the CYP2C19 poor metabolizer livers, suggesting an increased role for CYP3A4 in individuals lacking CYP2C19. These data indicate that voriconazole is a substrate for CYP2C9, CYP2C19, and CYP3A4, with CYP2C9 involvement being minimal in human liver microsomes. Genotype status for CYP2C19 and/or coadministration of drugs that modulate CYP2C19 or CYP3A4 activities could effect voriconazole plasma levels.

Cooperative regulation of myosin-actin interactions by a continuous flexible chain I: actin-tropomyosin systems

We present a model for cooperative myosin binding to the regulated actin filament, where tropomyosins are treated as a weakly-confined continuous flexible chain covering myosin binding sites. Thermal fluctuations in chain orientation are initially required for myosin binding, leaving kinked regions under which subsequent myosins may bind without further distortion of the chain. Statistical mechanics predicts the fraction of sites with bound myosin-S1 as a function of their affinities. Published S1 binding curves to regulated filaments with different tropomyosin isoforms are fitted by varying the binding constant, chain persistence length nu (in actin monomers), and chain kink energy A from a single bound S1. With skeletal tropomyosin, we find an S1 actin-binding constant of 2.2 x 10(7) M(-1), A = 1.6 k(B)T and nu = 2.7. Similar persistence lengths are found with yeast tropomyosin. Larger values are found for tropomyosin-troponin in the presence of calcium (nu = 3.7) and tropomyosins from smooth muscle and fibroblasts (nu = 4.5). The relationship of these results to structural information and the rigid-unit model of McKillop and Geeves is discussed.

Central nervous system inflammation is a hallmark of pathogenesis in mouse models of GM1 and GM2 gangliosidosis

Mouse models of the GM2 gangliosidoses [Tay-Sachs, late onset Tay-Sachs (LOTS), Sandhoff] and GM1 gangliosidosis have been studied to determine whether there is a common neuro-inflammatory component to these disorders. During the disease course, we have: (i) examined the expression of a number of inflammatory markers in the CNS, including MHC class II, CD68, CD11b (CR3), 7/4, F4/80, nitrotyrosine, CD4 and CD8; (ii) profiled cytokine production [tumour necrosis factor alpha (TNF alpha), transforming growth factor (TGF beta 1) and interleukin 1 beta (IL1 beta)]; and (iii) studied blood-brain barrier (BBB) integrity. The kinetics of apoptosis and the expression of Fas and TNF-R1 were also assessed. In all symptomatic mouse models, a progressive increase in local microglial activation/expansion and infiltration of inflammatory cells was noted. Altered BBB permeability was evident in Sandhoff and GM1 mice, but absent in LOTS mice. Progressive CNS inflammation coincided with the onset of clinical signs in these mouse models. Substrate reduction therapy in the Sandhoff mouse model slowed the rate of accumulation of glycosphingolipids in the CNS, thus delaying the onset of the inflammatory process and disease pathogenesis. These data suggest that inflammation may play an important role in the pathogenesis of the gangliosidoses.

Binding of dentin noncollagenous matrix proteins to biological mineral crystals: an atomic force microscopy study

Noncollagenous matrix proteins (NCPs) of dental hard tissues (dentin, cementum) are involved, both temporally and spatially, in the mineralization of their collagen matrices. Two of the NCPs thought to initiate mineral nucleation and control crystal growth in dentin, are dentin phosphoproteins (DPP) and dentin sialoprotein (DSP). Control of crystal growth would depend on the binding capacity of these two molecules, which may be related to the charge domains on the crystals and/or the phosphorylation of the protein. Phosphophoryn (a highly phosphorylated DPP) and DSP were isolated, purified, and characterized from the immature root apicies of human teeth. Dephosphorylation of phosphophoryn was carried out using bovine intestinal alkaline phosphatase. Enamel crystals were prepared from the maturation stage of developing rat incisor enamel. Protein-coated crystals were prepared for viewing in an atomic force microscope fluid cell using tapping mode. Desorption of the proteins was achieved using a phosphate buffer and surface roughness measurements were obtained from all specimens. Time-lapsed images of the crystals showed "nanospheres" of protein distributed along the crystals but only the phosphophoryn-coated crystals showed a distinctive banding pattern, which was still visible after the phosphate desorption experiments. The surface roughness measurements were statistically greater (P <0.01) when compared to the control for only the phosphophoryn-coated specimens. It is hypothesized that the phosphophoryn binding may be associated with charge arrays on the crystal surface and its phosphorylation. Also, based on its affinity for the crystalsurfaces, phosphophoryn seems the most likely candidate for controlling dentin crystal growth and morphology.

Are chemically reactive metabolites responsible for adverse reactions to drugs?

Low molecular weight organic chemicals can be transformed by normal drug-metabolising systems into short-lived metabolites that are inherently reactive towards cellular macromolecules. There is direct evidence that the formation of such chemically reactive metabolites may lead to mutagenesis, carcinogenicity, apoptosis and necrosis in both cell and animal models. A number of drugs associated with non-pharmacological drug toxicities in man have been shown to undergo bioactivation either in vivo or in vitro. We have therefore examined the evidence for the role of reactive metabolites in the three most common drug-induced toxicities: hepatotoxicity, skin reactions and blood dyscrasias.