Extraction of benzoylecgonine (cocaine metabolite) and opiates (codeine and morphine) from urine samples using the Zymark RapidTrace

The Zymark RapidTrace automated solid-phase extraction system has been evaluated for use in the urine drug-testing laboratory. Methods for cocaine metabolite (benzoylecgonine) and opiates (codeine and morphine) are described and evaluated. The linearity, precision, accuracy, recovery, and carryover statistics of these analytical protocols are presented. The advantages of extraction using the RapidTrace instead of solid-phase extraction with the manual vacuum manifold or liquid-liquid extraction methods are described.     

Bacterial Antigens Reduced the Inhibition Effect of Capsaicin on Cal 27 Oral Cancer Cell Proliferation

Oral cancer is a major global health problem with high incidence and low survival rates. The oral cavity contains biofilms as dental plaques that harbour both Gram-negative and Gram-positive bacterial antigens, lipopolysaccharide (LPS) and lipoteichoic acid (LTA), respectively. LPS and LTA are known to stimulate cancer cell growth, and the bioactive phytochemical capsaicin has been reported to reverse this effect. Here, we tested the efficacy of oral cancer chemotherapy treatment with capsaicin in the presence of LPS, LTA or the combination of both antigens. LPS and LTA were administered to Cal 27 oral cancer cells prior to and/or concurrently with capsaicin, and the treatment efficacy was evaluated by measuring cell proliferation and apoptotic cell death. We found that while capsaicin inhibits oral cancer cell proliferation and metabolism (MT Glo assay) and increases cell death (Trypan blue exclusion assay and Caspase 3/7 expression), its anti-cancer effect was significantly reduced on cells that are either primed or exposed to the bacterial antigens. Capsaicin treatment significantly increased oral cancer cells’ suppressor of cytokine signalling 3 gene expression. This increase was reversed in the presence of bacterial antigens during treatment. Our data establish a rationale for clinical consideration of bacterial antigens that may interfere with the treatment efficacy of oral cancer.     

Double tracking in the sigmoid colon

Double tracking of barium in the sigmoid colon has been associated with granulomatous colitis by some; others consider it a sign of peridiverticulitis. Patients who showed no evidence of inflammatory disease elsewhere in the large intestine were analysed. The pathological diagnosis was diverticulitis in 29 of 35 cases, and granulomatous diverticulitis in only 1. In 5 the underlying process was perforated carcinoma of the sigmoid colon. In those with paracolonic sinus tracts due to peridiverticulitis, pathological study demonstrated tracts extrinsic to the muscularis and usually traceable to a perforated diverticulum. Long-term follow-up disclosed no evidence of subsequent inflammatory bowel disease.     

Across-wind vibrations of structures of circular cross-section. Part I. Development of a mathematical model for two-dimensional conditions

A model is presented for predicting the across-wind response of constant-diameter circular cylinders vibrating in a mode of uniform amplitude and subject to uniform flow. A key feature of the model is the representation of all motion-dependent phenomena by a nonlinear aerodynamic damping force. This force coexists with the fluctuating force which arises from vortex shedding on a stationary cylinder, and the two forces are assumed to be uncorrelated.The ability of the device used in representing the motion-induced force to model certain aeroelastic characteristics associated with vibrating cylinders is demonstrated. The device is shown to be capable of successfully reproducing two effects; namely, the increase of the spanwise correlation of forces with increasing amplitude, and the phenomenon of “lock in” where the shedding frequency is apparently dictated by the vibration frequency.The model is developed within the framework of random-vibration theory, and a number of simplifying assumptions are necessary to incorporate the nonlinear aerodynamic damping force and also to account for the influence of turbulence. Numerical experiments, undertaken to examine the nature of the approximations involved in the assumptions adopted, are described. The results of the numerical experiments are very encouraging and justify the simplifications made in the modelling process.     

Across-wind vibrations of structure of circular cross-section. Part II. Development of a mathematical model for full-scale application

A model is presented for predicting the across-wind response of slender structures of circular cross-section to turbulent shear flow. Fundamental aspects of the model have been described in a companion paper [1], the key feature of the model being the representation of all motion-dependent phenomena by a nonlinear damping force. The development described in this paper is concerned with extending the earlier work, which was confined to two-dimensional laboratory configuration, such that the model is able to provide estimates of response for full-scale structures.Based on the work outlined above, a computer program was developed to obtain estimates of response in full-scale situations. The program was used to compute the response of a 330 m TV tower and the results were compared with the measured response. In general, the computed and measured responses are in fair agreement.The uncertainties associated with some of the input parameters are noted, and are considered a greater hindrance to further development than any theoretical difficulties.     

ML218 HCl Is More Efficient Than Capsaicin in Inhibiting Bacterial Antigen-Induced Cal 27 Oral Cancer Cell Proliferation

The bacterial antigen, lipopolysaccharide (LPS) and disruptions in calcium channels are independently known to influence oral cancer progression. Previously, we found that bacterial antigens, LPS and lipoteichoic acid (LTA) act as confounders during the action of capsaicin on Cal 27 oral cancer proliferation. As calcium channel drugs may affect oral cancer cell proliferation, we investigated the effect of ML218 HCl, a T-type voltage-gated calcium channel blocker, on the proliferation of Cal 27 oral cancer cells. We hypothesized that ML218 HCl could effectively reduce LPS-induced oral cancer cell proliferation. LPS and LTA antigens were added to Cal 27 oral cancer cells either prior to and/or concurrently with ML218 HCl treatment, and the efficacy of the treatment was evaluated by measuring Cal 27 proliferation, cell death and apoptosis. ML218 HCl inhibited oral cancer cell proliferation, increased apoptosis and cell death, but their efficacy was significantly reduced in the presence of bacterial antigens. ML218 HCl proved more effective than capsaicin in reducing bacterial antigen-induced Cal 27 oral cancer cell proliferation. Our results also suggest an interplay of proliferation factors during the bacterial antigens and calcium channel drug interaction in Cal 27. Bacterial antigen reduction of drug efficacy should be considered for developing newer pharmacological agents or testing the efficacy of the existing oral cancer chemotherapeutic agents. Finally, voltage gated calcium channel drugs should be considered for future oral cancer research.     

Proteome of Staphylococcus aureus Biofilm Changes Significantly with Aging

Staphylococcus aureus is a notorious biofilm-producing pathogen that is frequently isolated from implantable medical device infections. As biofilm ages, it becomes more tolerant to antimicrobial treatment leading to treatment failure and necessitating the costly removal of infected devices. In this study, we performed in-solution digestion followed by TMT-based high-throughput mass spectrometry and investigated what changes occur in the proteome of S. aureus biofilm grown for 3-days and 12-days in comparison with 24 h planktonic. It showed that proteins associated with biosynthetic processes, ABC transporter pathway, virulence proteins, and shikimate kinase pathway were significantly upregulated in a 3-day biofilm, while proteins associated with sugar transporter, degradation, and stress response were downregulated. Interestingly, in a 3-day biofilm, we observed numerous proteins involved in the central metabolism pathways which could lead to biofilm growth under diverse environments by providing an alternative metabolic route to utilize energy. In 12-day biofilms, proteins associated with peptidoglycan biosynthesis, sugar transporters, and stress responses were upregulated, whereas proteins associated with ABC transporters, DNA replication, and adhesion proteins were downregulated. Gene Ontology analysis revealed that more proteins are involved in metabolic processes in 3dwb compared with 12dwb. Furthermore, we observed significant variations in the formation of biofilms resulting from changes in the level of metabolic activity in the different growth modes of biofilms that could be a significant factor in S. aureus biofilm maturation and persistence. Collectively, potential marker proteins were identified and further characterized to understand their exact role in S. aureus biofilm development, which may shed light on possible new therapeutic regimes in the treatment of biofilm-related implant-associated infections.     

Real-time PCR quantification of Vibrio parahaemolyticus in oysters using an alternative matrix

This study examined the relationship between levels of total Vibrio parahaemolyticus found in oyster tissues and mantle fluid with the goal of using mantle fluid as a template matrix in a new quantitative real-time PCR assay targeting the thermolabile hemolysin (tlh) gene for the enumeration of total V. parahaemolyticus in oysters. Oysters were collected near Mobile Bay, Ala., in June, July, and September and tested immediately after collection and storage at 26 degrees C for 24 h. Initial experiments using DNA colony hybridization targeting tlh demonstrated that natural V. parahaemolyticus levels in the mantle fluid of individual oysters were strongly correlated (r = 0.85, P < 0.05) with the levels found in their tissues. When known quantities of cultured V. parahaemolyticus cells were added to real-time PCR reactions that contained mantle fluid and oyster tissue matrices separately pooled from multiple oysters, a strong linear correlation was observed between the real-time PCR cycle threshold and the log concentration of cells inoculated into each PCR reaction (mantle fluid: r = 0.98, P < 0.05; and oyster: r = 0.99, P < 0.05). However, the mantle fluid exhibited less inhibition of the PCR amplification than the homogenized oyster tissue. Analysis of natural V. parahaemolyticus populations in mantle fluids using both colony hybridization and real-time PCR demonstrated a significant (P < 0.05) but reduced correlation (r = -0.48) between the two methods. Reductions in the efficiency of the real-time PCR that resulted from low population densities of V. parahaemolyticus and PCR inhibitors present in the mantle fluid of some oysters (with significant oyster-to-oyster variation) contributed to the reduction in correlation between the methods that was observed when testing natural V. parahaemolyticus populations. The V. parahaemolyticus-specific real-time PCR assay used for this study could estimate elevated V. parahaemolyticus levels in oyster mantle fluid within 1 h from sampling time.     

Multipolar plasmonic resonances in silver nanowire antennas imaged with a subnanometer electron probe

We detect short-range surface plasmon-polariton (SR-SPP) resonances setup in individual silver nanoantenna structures at high-spatial resolution with a scanning, subnanometer electron probe. Both even and odd multipolar resonant modes are resolved up to sixth order, and we measure their spatial distribution in relation to nanoantenna structures at energies down to 0.55 eV. Fabry-Perot type SR-SPP reflection phase shifts are calculated from direct measurements of antinode spacings in high-resolution plasmonic field maps. We observe resonant SR-SPP antinode bunching at nanoantenna terminals in high-order resonant modes, and antinode shifts in nonhomogeneous local environments. Finally, we achieve good agreement of our experimental SR-SPP maps with numerical calculations of photon excited near fields, using a novel integrated photon excitation geometry.