Little is known about the pathogenesis of cough in idiopathic pulmonary fibrosis (IPF). We hypothesized that abnormalities of respiratory tract tachykinin-containing sensory nerves may be implicated. We studied cough response to capsaicin, substance P (SP), and bradykinin in 10 healthy control subjects and 10 patients with IPF. Six patients were tested before and after steroid therapy. Induced sputum cell counts and neurotrophic factor levels were also measured in 13 patients and 13 control subjects. The results show that cough sensitivity to capsaicin was greater in patients (p < 0.01). Neither SP nor bradykinin induced cough in normal subjects. SP and bradykinin induced cough in 7/10 patients (p < 0.002) and 2/10 patients (not significant) with IPF, respectively. Prednisolone caused a reduction in cough sensitivity to capsaicin (p < 0.05) and SP (p < 0.05) in all six patients treated. There were significantly more neutrophils (p = 0.001) and higher levels of nerve growth factor (p < 0.01) and brain-derived neurotrophic factor (p < 0.01) in patient's sputa. These findings suggest functional upregulation of lung sensory neurones in IPF. The cough response to inhaled SP in most patients may reflect disrupted respiratory epithelium. The response to corticosteroids demonstrates that the cough is amenable to therapy.

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The natural occurrence of cyclic nucleotides in higher plants, formerly a topic of fierce debate, is now established, as is the presence of nucleotidyl cyclases and cyclic nucleotide phosphodiesterases capable of their synthesis and breakdown. Here we describe the significant properties of cyclic nucleotides, also outlining their second messenger functions and the history of plant cyclic nucleotide research over its first three decades. Findings of the last five years are detailed within the context of the functional role of cyclic nucleotides in higher plants, with particular emphasis upon nucleotidyl cyclases and cyclic nucleotide-responsive protein kinases, -binding proteins and -gated ion channels, with future objectives and strategies discussed.

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An in-depth study of the fragmentation pathway of guanosine was conducted by using an in-source collision-induced dissociation high-mass accuracy tandem mass spectrometry experiment. The equivalent of MS 4 data, a level of information normally achieved on ion trap instruments, was obtained on a Q-TOF mass spectrometer. The combination of the features of high-resolution, accuracy, and in-source CID permitted the unambiguous elucidation of the different fragmentation pathways. Furthermore the elemental compositions of the product ions generated were assigned and their mutual genealogical relationships established. Formerly proposed dissociation pathways of guanosine were revisited and elaborated on more deeply. Furthermore, the presence of H 2 O in the collision cell of several tandem MS instruments was demonstrated and its effect on the product ion spectra investigated. The neutral gain of H 2 O by particular fragments of guanosine was experimentally proven by using argon, saturated with H 2 18 O, as the collision gas. Data indicating the occurrence of more complex reactions in the collision cell as a result of the presence of H 2 O were produced, specifically relating to neutral gain/neutral loss sequences. In silico calculations supported the experimental observation of neutral gain by guanosine fragments and predicted a similar behavior for adenosine. The latter was subsequently experimentally confirmed. , and nucleoside levels in urine have the potential to act as cancer biomarkers [2][3][4][5]. As their occurrence is both ubiquitous and quantitatively varying [6,7] their unequivocal characterization is crucial.For guanine alone over 20 natural variants are known to occur in RNA [6], which makes structural identification a challenging task. In our earlier LC-ESI-MS/MS experiments of urinary nucleosides [8], unexpected product ions of guanosine and its methylated derivatives were detected. The presence of these ions prompted us to perform additional mass spectrometric studies since their origin was not straightforward. This report provides an in-depth study of the fragmentation behavior of guanosine under lowenergy CID conditions, revealing H 2 O addition to specific fragments.We also wish to demonstrate the use of a Q-TOF mass spectrometer in the collection of the equivalent of MS 4 data, a level of information normally acquired only in ion trap-or FT-MS n experiments [9,10]. This was achieved by making optimal use of "in

The development of an on-line automated SPE-HPLC--ESI-MS method is described for targeted metabolomic analysis of urinary modified nucleoside levels. The setup comprises a boronate affinity column as a trapping device, a hydrophilic interaction chromatography (HILIC) separation and information-dependent MS detection modes. The system was optimized using standards and tested on biological samples, detecting a number of modified nucleosides. Other urinary biomarkers could also be analyzed by the system developed: for example, the urinary nucleobases were also available for analysis. A simultaneous creatinine-monitoring experiment was also demonstrated to be viable when utilizing the method, which is of benefit as creatinine is a urinary normalizing factor.

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