Use of Anti-Glycopeptidolipid-Core Antibodies Serology for Diagnosis and Monitoring of Mycobacterium avium Complex Pulmonary Disease in the United States.

Background: There is an unmet need for rapid, accurate, and noninvasive assays for diagnosis and monitoring of Mycobacterium avium complex pulmonary disease (MAC-PD). We evaluated the diagnostic accuracy of an anti-glycopeptidolipid (GPL)-core immunoglobulin A (IgA) antibody test in a US cohort of MAC patients, and we described serial serology changes during antimicrobial therapy. Methods: We identified serum samples from MAC patients starting treatment at enrollment and control subjects with or without bronchiectasis within OHSU's NTM Biobank. We conducted diagnostic test accuracy. Changes in mean levels of anti-GPL-core IgA antibodies between 0 and 3, 6, or 12 months after treatment start were assessed using the Student's paired t test. Pearson's correlation coefficient was calculated for IgA antibody levels and Student paired t test measures. Results: We included 25 MAC patients and 18 controls. At baseline, IgA antibody concentrations in MAC patients (3.40 ± 6.77 U/mL) were significantly higher than in controls without bronchiectasis (0.14 ± 0.03 U/mL, P = .02). Sensitivity and specificity for MAC-PD in this population was 48% and 89% (cutoff point 0.7 U/mL), respectively. Among MAC patients starting antimicrobial therapy, mean IgA levels decreased 0.3202 U/mL (P = .86) at month 3, 0.8678 U/mL (P = .47) at month 6, and 1.9816 U/mL (P = .41) at 1 year. Quality of Life-Bronchiectasis Respiratory Symptom Scale improvement correlated with decreasing IgA titers after 12 months of treatment in MAC patients (r = -0.50, P = .06). Conclusions: Anti-GPL-core IgA antibody levels are relatively specific for MAC-PD and decrease with treatment. Larger studies are warranted to evaluate the role of IgA serology in monitoring treatment response or for disease relapse/reinfection.

Investigation of the mechanism for current induced network failure for spray deposited silver nanowires.

Silver nanowires are one of the prominent candidates for the replacement of the incumbent indium tin oxide in thin and flexible electronics applications. Their main drawback is their inferior electrical robustness. Here, the mechanism of the short duration direct current induced failure in large networks is investigated by current stress tests and by examining the morphology of failures. It is found that the failures are due to the heating of the film and they initiate at the nanowire junctions, indicating that the main failure mechanism is based on the Joule heating of the junctions. This failure mechanism is different than what has been seen in literature for single nanowires and sparse networks. In addition, finite element heating simulations are performed to support the findings. Finally, we suggest ways of improving these films, in order to make them more suitable for device applications.

How should laboratories communicate with primary care? Obtaining general practitioners' views.

AIMS: Recognising the importance of communication with our primary care colleagues, focus groups were held with GPs to determine how they perceived the current lines of communication with their local microbiology laboratory and the PHLS, and how they could be improved. METHODS: Focus groups were held in Plymouth, Gloucester, Bristol and Hereford. Between four and 10 GPs and/or PCG Board members attended each workshop. The modes of communication i.e. websites, face-to-face contact, laboratory reporting, telephone advice, newsletters, guidance and surveillance were discussed. RESULTS: Microbiology websites should be user friendly, with clear labelling as to whom the page is directed. They should contain locally relevant data, antibiotic guidance and information leaflets. Despite great variation in laboratory reporting protocols GPs were mostly happy with reports received. Results, especially serology, should contain a clear conclusion and could refer to a website for further information. Electronic reporting was enthusiastically awaited. All GPs felt they had excellent access to telephone advice. GPs would value data and guidance on their use of diagnostic tests. CONCLUSION: These workshops highlight the variation in laboratory reporting protocols that should be addressed. Website development for GPs should include locally relevant data. GPs would value details of their laboratory use and costs.

Metrology and modeling of microchannel plate x-ray optics.

A Monte Carlo ray-trace model of nonideal microchannel plate (MCP) x-ray optics is described. The model takes into account angular misalignments, both transverse and axial, between the channels and the multifiber bundles; pincushion distortion of the square channels; radiusing of the channel vertices; and scattering from microroughness of the channel walls. The model also takes into account the spectrum and nonisotropic nature of the illuminating radiation. Using optical, scanning electron, and atomic force microscopies, as well as x-ray scattering data obtained with a laser plasma x-ray source, we have determined a partial error budget for the focusing action of a real square-pore MCP, leaving only the interchannel long-axis misalignment to be found by comparison of simulated and measured images. The power of the Monte Carlo model in directing the future development of MCP optics is illustrated.

Inhibition of neutrophil superoxide secretion by the preservative, methylhydroxybenzoate: effects mediated by perturbation of intracellular Ca2+?

The preservative, methylhydroxybenzoate inhibited O2- secretion from human neutrophils activated by both the chemotactic peptide fMet-Leu-Phe and phorbol myristate acetate (PMA): the low level of oxidant secretion activated by the ionophore A23187 was similarly reduced in preservative-treated suspensions. Oxidant secretion was similarly reduced in fMet-Leu-Phe and A23187 treated suspensions in which intracellular Ca2+ was buffered by loading with Quin-2, indicating that methylhydroxybenzoate may exert its effects by perturbation of intracellular Ca2(+)-dependent processes. Methylhydroxybenzoate could mimic EGTA in preventing the Ca2+ dependent enhancement of trypsin activity and could also bind this cation in experiments using a Ca2+ electrode, although the preservative bound Ca2+ more slowly and had a lower affinity than EGTA. These data indicate that methylhydroxybenzoate may exert its effects on neutrophils by perturbation of Ca2(+)-dependent activation pathways and this phenomenon may also explain its other known pharmacological effects. Furthermore, these observations provide an insight into the mechanisms by which intracellular Ca2+ may regulate oxidant secretion.

The effect of exogenously-supplied nucleosides and nucleotides and the involvement of adenosine 3':5'-cyclic monophosphate (cyclic AMP) in the yeast mycelium transition of Ceratocystis (= Ophiostoma) ulmi.

The yeast-mycelium transition of Ceratocystis (= Ophiostoma) ulmi (NRRL 6404) was induced by exogenously-supplied nucleosides and nucleotides in defined liquid media. During the yeast-mycelium transition, intracellular adenosine 3':5'-cyclic monophosphate (cAMP) levels increased and maximum levels coincided with maximum germination. This, coupled with findings that the cAMP phosphodiesterase inhibitors, theophylline and caffeine, also induced germination and elevated levels of intracellular cAMP, indicated the involvement of cAMP in the regulation of the yeast-mycelium transition.

Element localisation and distribution in the fungi Aureobasidium pullulans and Aspergillus niger, measured using the Oxford scanning proton microprobe.

The distribution and relative concentrations of essential elements were determined in germ tubes of Aureobasidium pullulans and hyphae of Aspergillus niger using the Oxford scanning proton microprobe. In both fungi, K, P and S were the major constituents, with Ca, Na and trace metals like Cu, Mn, Fe and Zn present at lower levels. In A. pullulans, elements were not distributed uniformly throughout the cells and, in general, the highest elemental concentrations occurred at the tip and in the older parts of the germ tube, particularly where there was yeast-like cell or branch development. In A. niger, elemental distribution was more uniform and there was a general gradient of increasing concentration away from the hyphal tip followed by a drop in levels in older regions. The scanning proton microprobe appears to have considerable potential for the investigation of fungal differentiation and morphogenesis.