Airway epithelial cell apoptosis and inflammation in COPD, smokers and non-smokers

We hypothesised that primary bronchial epithelial cells (PBECs) from subjects with COPD respond differently to Pseudomonas aeruginosa lipopolysaccharide (PA LPS) after cigarette smoke extract (CSE) exposure than PBECs obtained from smokers without airflow obstruction (SWAO) and non-smokers (NS).PBECs from 16 COPD subjects, 10 SWAOand 9 NS were cultured at air-liquid interface. Cultures were incubated with CSE prior to stimulation with PA LPS. IL-6 and IL-8 were measured by ELISA and Toll-like receptor 4 expression by FACS. Activation of NF-?B was determined by western blotting and ELISA, and MAPK and caspase-3 activity by western blotting. Apoptosis was evaluated using Annexin-V staining and the terminal transferase-mediated dUTP nick end-labeling (TUNEL) methods.Constitutive release of IL-8 and IL-6 was greatest from the COPD cultures.However, CSE pre-treatment followed by PA LPS stimulation reduced IL-8 release from COPD PBECs, but increased it from cells of SWAOand NS. TLR-4 expression,MAPK and NF-?B activation in COPD cultures were reduced after CSE treatment, but not in the SWAOor NS groups, which was associated with increased apoptosis.CSE attenuates inflammatory responses to LPS in cells from people with COPD but not those from non-smoking individuals and those who smoke without airflow obstruction.

PRIMARY STRUCTURES AND BIOLOGICAL-ACTIVITIES OF SUBSTANCE-P-RELATED PEPTIDES FROM THE BRAIN OF THE DOGFISH, SCYLIORHINUS-CANICULA

Two peptides with substance-P-like immunoreactivity were isolated in pure form from an extract of the brain of the elasmobranch fish, Scyliorhinus canicula (european common dogfish). One peptide was identical to scyliorhinin I, previously identified in dogfish intestine, and the second was the undecapeptide Lys-Pro-Arg-Pro-Gly-Gln-Phe-Phe-Gly-Leu-Met-CONH2 which is structurally similar to mammalian substance P Scyliorhinin II or a peptide analogous to mammalian neurokinin A were not detected in the extract. Synthetic dogfish substance P ([Lys1, Arg3, Gly5]substance P) was approximately threefold more potent than mammalian substance P (K(d) = 0.21 +/- 0.11 nM versus K(d)= 0.74 +/- 0.17 nM; mean +/- SD; n = 6) in inhibiting the binding of I-125-labelled substance P to neurokinin (NK1) receptors in rat submandibular gland membranes. The vasodilator action of tachykinins in mammals is mediated primarily through interaction with NK1 receptors. Bolus intravenous injections of [Lys1, Arg3, Gly5]substance P (100 pmol) and scyliorhinin I (100 pmol) produced appreciable (>4 kPa) decreases in arterial blood pressure in the rat whereas intravenous injections of up to 5 nmol of the peptides into conscious, unrestrained dogfish produced no change in arterial blood pressure, pulse amplitude or heart rate. Injections of greater amounts of the peptides (10-50 nmol) produced a slight increase (400-667 Pa) in blood pressure. The data indicate that mammalian-type NK1 tachykinin receptors are not involved in cardiovascular regulation in elasmobranch fish.

Intestinal permeability tests in coeliac disease

Intestinal permeability tests have been used to screen for a wide range of small intestinal diseases, including coeliac disease and enteric infections. Several probe molecules have been used to investigate intestinal permeability including monosaccharides, disaccharides, 51Cr-EDTA and polyethyleneglycol. While many factors may affect intestinal permeability tests, the use of two probe molecules, for example, lactulose and mannitol, and the expression of the result as a ratio minimises the effects of these extraneous factors. Rendering the test solution hyperosmolar was also found to increase the sensitivity of the test in detecting coeliac disease. Intestinal permeability is characteristically elevated in untreated coeliac disease, with a sensitivity of up to 96% for the dual sugar techniques. The reason for this is a consistent increase in the absorption of lactulose (via the paracellular route) due to increased "leakiness" of the intestine and a reduction in the absorption of mannitol (via the transcellular route) due to a reduction in surface area as a result of villous atrophy. The intestinal permeability test allows subjects to be selected for jejunal biopsy in whom the clinical features are compatible with coeliac disease and in timing a follow-up biopsy. It has been postulated that raised intestinal permeability may be involved in the pathogenesis of coeliac disease. Recently, serum measurements of the probe molecules may have a valuable role, particularly in paediatric patients. Sucrose permeability has also been proposed as an accurate marker of adult coeliac disease and shows promise as a noninvasive test.

Plasma concentrations of glucagon-like peptide-2 in adult patients with treated and untreated coeliac disease

Coeliac disease is a common chronic inflammatory enteropathy characterized by villous atrophy and crypt hyperplasia in the small intestine. The mechanism of the intestinal damage in coeliac disease remains unclear. Glucagon-like peptide (GLP)-2 is an enterotrophic peptide that causes crypt hyperplasia and intestinal cell proliferation. We postulate that GLP-2 may be involved in the mucosal changes found in coeliac disease.

IHG-1 amplifies TGF-beta1 signaling and is increased in renal fibrosis

Induced in high glucose-1 (IHG-1) is an evolutionarily conserved gene transcript upregulated by high extracellular glucose concentrations, but its function is unknown. Here, it is reported that the abundance of IHG-1 mRNA is nearly 10-fold higher in microdissected, tubule-rich renal biopsies from patients with diabetic nephropathy compared with control subjects. In the diabetic nephropathy specimens, in situ hybridization localized IHG-1 to tubular epithelial cells along with TGF-beta1 and activated Smad3, suggesting a possible role in the development of tubulointerstitial fibrosis. Supporting this possibility, IHG-1 mRNA and protein expression also increased with unilateral ureteral obstruction. In the HK-2 proximal tubule cell line, overexpression of IHG-1 increased TGF-beta1-stimulated expression of connective tissue growth factor and fibronectin. IHG-1 was found to amplify TGF-beta1-mediated transcriptional activity by increasing and prolonging phosphorylation of Smad3. Conversely, inhibition of endogenous IHG-1 with small interference RNA suppressed transcriptional responses to TGF-beta1. In summary, IHG-1, which increases in diabetic nephropathy, may enhance the actions of TGF-beta1 and contribute to the development of tubulointerstitial fibrosis.

Diclofenac disposition in Indian cow and goat with reference to Gyps vulture population declines

Gyps vultures across India are declining rapidly and the NSAID diclofenac has been shown to be the major cause. Vultures scavenge livestock carcasses that have been treated with diclofenac within the days preceding death. We present data on diclofenac disposition in Indian cow and goat, and field data on the prevalence of diclofenac in carcases in the environment. In the disposition experiment, animals were treated with a single intramuscular injection of diclofenac at 1000 microg kg-1 bw. In cow, diclofenac was detectable in liver, kidney and intestine up to 71 h post-treatment; in plasma, half-life was 12.2 h. In goat, tissue residues were undetectable after 26 h. Prevalence of diclofenac in liver from 36 dead livestock collected in the field was 13.9%. Data suggest that diclofenac residues in Indian cow and goat are short-lived, but diclofenac prevalence in carcasses available to vultures may still be very high.

Detection of intrastrain antigenic variation of Bacteroides fragilis surface polysaccharides by monoclonal antibody labelling

Bacteroides fragilis is a constituent of the normal resident microbiota of the human intestine and is the gram-negative obligately anaerobic bacterium most frequently isolated from clinical infection. Surface polysaccharides are implicated as potential virulence determinants. We present evidence of within strain immunochemical variation of surface polysaccharides in populations that are noncapsulate by light microscopy as determined by monoclonal antibody labelling. Expression of individual epitopes can be enriched from a population of an individual strain by use of immunomagnetic beads. Also, individual colonies in which either >94% or 94% of the bacteria carry a given epitope, there is no enrichment for other epitopes recognized by different polysaccharide-specific monoclonal antibodies. This intrastrain variation has important implications for the development of potential vaccines or immunodiagnostic tests.

Impact of cigarette smoke exposure on host-bacterial pathogen interactions

The human respiratory tract of individuals with normal lung function maintains a fine-tuned balance, being asymptomatically colonised by the normal microbiota in the upper airways and sterile in the lower tract. This equilibrium may be disrupted by the exposure to insults such as cigarette smoke. In the respiratory tract, the complex and noxious nature of inhaled cigarette smoke alters host-microorganisminteraction dynamics at all anatomical levels, causing infections in many cases. Moreover, continuous exposure to cigarette smoke itself causes deleterious effects on the host that can trigger the development of chronic respiratory diseases, such as chronic obstructive pulmonary disease (COPD) and lung cancer. COPD is an irreversible airflow obstruction associated with emphysema, fibrosis, mucus hypersecretion and persistent colonisation of the lower airways by opportunistic pathogens. COPD patients keep a stable (without exacerbation) but progressively worsening condition and suffer periodic exacerbations caused, in most cases, by infections. Although smoking and smoking-associated diseases are associated with a high risk of infection, most therapies aim to reduce inflammatory parameters, but do not necessarily take into account the presence of persistent colonisers. The effect of cigarette smoke on host-pathogen interaction dynamics in the respiratory tract, together with current and novel therapies, is discussed. Copyright©ERS 2012.

IHG-1 promotes mitochondrial biogenesis by stabilizing PGC-1α

Increased expression of Induced-by-High-Glucose 1 (IHG-1) associates with tubulointerstitial fibrosis in diabetic nephropathy. IHG-1 amplifies TGF-ß1 signaling, but the functions of this highly-conserved protein are not well understood. IHG-1 contains a putative mitochondrial-localization domain, and here we report that IHG-1 is specifically localized to mitochondria. IHG-1 overexpression increased mitochondrial mass and stabilized peroxisome proliferator-activated receptor ? coactivator-1a (PGC-1a). Conversely, inhibition of IHG-1 expression decreased mitochondrial mass, downregulated mitochondrial proteins, and PGC-1a-regulated transcription factors, including nuclear respiratory factor 1 and mitochondrial transcription factor A (TFAM), and reduced activity of the TFAM promoter. In the unilateral ureteral obstruction model, we observed higher PGC-1a protein expression and IHG-1 levels with fibrosis. In a gene-expression database, we noted that renal biopsies of human diabetic nephropathy demonstrated higher expression of genes encoding key mitochondrial proteins, including cytochrome c and manganese superoxide dismutase, compared with control biopsies. In summary, these data suggest that IHG-1 increases mitochondrial biogenesis by promoting PGC-1a-dependent processes, potentially contributing to the pathogenesis of renal fibrosis.

Transpupillary thermotherapy for choroidal melanoma:Tumor control and visual results in 100 consecutive cases

Objective: The authors evaluated the results of primary transpupillary thermotherapy for choroidal melanoma in 100 cases. Design: Prospective nonrandomized analysis of treatment method. Participants: One hundred patients with choroidal melanoma were studied. Main Outcome Measures: Tumor response, ocular side effects, and visual results. Results: Of 100 consecutive patients with choroidal melanoma treated with transpupillary thermotherapy, the mean tumor basal diameter was 7.1 mm and tumor thickness was 2.8 mm. The tumor margin touched the optic disc in 34 eyes (34%) and was beneath the fovea in 42 eyes (42%). Documented growth was present in 64 eyes (64%), and known clinical risks for growth were present in all of the remaining 36 eyes (36%), with an average of 4 of 5 statistical risk factors for growth per tumor. After a mean of three treatment sessions and 14 months of follow-up, the mean tumor thickness was reduced to 1.4 mm. Treatment was successful in 94 eyes (94%) and failed in 6 eyes (6%). Three patients with amelanotic tumors showed no initial response to thermotherapy, but subsequent intravenous indocyanine green administration during thermotherapy resulted in improved heat absorption and tumor regression to a flat scar. The six eyes classified as treatment failures included four eyes with tumors that showed partial or no response to thermotherapy, thus requiring plaque radiotherapy or enucleation, and two eyes with recurrence, subsequently controlled with additional thermotherapy. After treatment, the visual acuity was the same (within 1 line) or better than the pretreatment visual acuity in 58 eyes (58%) and worse in 42 eyes (42%). The main reasons for poorer vision included treatment through the foveola for subfoveal tumor (25 eyes), retinal traction (10 eyes), retinal vascular obstruction (5 eyes), optic disc edema (1 eye), and unrelated ocular ischemia (1 eye). Temporal location (versus nasal and superior, P = 0.02) and greater distance from the optic disc (P = 0.04) were risks for retinal traction. Conclusions: Transpupillary thermotherapy may be an effective treatment for small posterior choroidal melanoma, especially those near the optic disc and fovea. Despite satisfactory local tumor control, ocular side effects can result in decreased vision. Longer follow- up will be necessary to assess the impact of thermotherapy on ultimate local tumor control and metastatic disease.

Multi-access communication system in a highly reverberant environment

We investigate by numerical EM simulation the potential communication channel capacity of a reverberant environment using the time reversal approach, excited at 2.4 GHz by ON-OFF keyed RF pulse excitation. It is shown that approximately 725 1.25MHz propagation channels can be allocated with the cavity contains a 4×4 ? or 1×1 ? LOS obstruction positioned between the transceiver antenna and the time reversal unit. Furthermore the results show that two co-located transceiver dipoles separated by a spacing of 3?/4 can successfully resolve a 10ns pulse. Our findings suggest that different independent channels with identical operating frequency can be realized in an enclosed environment such as ventilation duct or underground tunnel. This suggests that there is a possibility of implementing a parallel channel radio link with the minimum inter-antenna spacing of 3?/4 between the transceivers in a rich multipath environment. © 2012 IEEE.

Lipoxins attenuate renal fibrosis by inducing let-7c and suppressing TGFβR1

Lipoxins, which are endogenously produced lipid mediators, promote the resolution of inflammation, and may inhibit fibrosis, suggesting a possible role in modulating renal disease. Here, lipoxin A4 (LXA4) attenuated TGF-ß1-induced expression of fibronectin, N-cadherin, thrombospondin, and the notch ligand jagged-1 in cultured human proximal tubular epithelial (HK-2) cells through a mechanism involving upregulation of the microRNA let-7c. Conversely, TGF-ß1 suppressed expression of let-7c. In cells pretreated with LXA4, upregulation of let-7c persisted despite subsequent stimulation with TGF-ß1. In the unilateral ureteral obstruction model of renal fibrosis, let-7c upregulation was induced by administering an LXA4 analog. Bioinformatic analysis suggested that targets of let-7c include several members of the TGF-ß1 signaling pathway, including the TGF-ß receptor type 1. Consistent with this, LXA4-induced upregulation of let-7c inhibited both the expression of TGF-ß receptor type 1 and the response to TGF-ß1. Overexpression of let-7c mimicked the antifibrotic effects of LXA4 in renal epithelia; conversely, anti-miR directed against let-7c attenuated the effects of LXA4. Finally, we observed that several let-7c target genes were upregulated in fibrotic human renal biopsies compared with controls. In conclusion, these results suggest that LXA4-mediated upregulation of let-7c suppresses TGF-ß1-induced fibrosis and that expression of let-7c targets is dysregulated in human renal fibrosis.

The Effects of the Catalytic Converter on Two-Stroke Engine Performance, SAE Technical Paper 972741

The two-stroke engine, by its nature is very dependent on the unsteady gas dynamics within an exhaust system. This is demonstrated by the tuning effects on two-stroke engines, which have been well documented. In consideration of current emissions legislation, a two-stroke engine can be fitted with a catalytic converter for the outboard, utility or automotive markets. The catalytic substrate represents a major obstruction to the flow of exhaust gas, which hinders the progression of the main exhausted pulse, and in turn effects the scavenging of the cylinder and ultimately the performance of the engine.

Pharmacological characterization of a noninvasive, chronic, experimental dog model of nasal congestion

The present experiments were undertaken to pharmacologically characterize a noninvasive, chronic, experimental dog model of nasal congestion with the overall goal of developing an effective tool for studying the mechanism of action of nasal decongestant drugs.

Measurement of nasal patency in anesthetized and conscious dogs

Experiments were undertaken to characterize a noninvasive chronic, model of nasal congestion in which nasal patency is measured using acoustic rhinometry. Compound 48/80 was administered intranasally to elicit nasal congestion in five beagle dogs either by syringe (0.5 ml) in thiopental sodium-anesthetized animals or as a mist (0.25 ml) in the same animals in the conscious state. Effects of mast cell degranulation on nasal cavity volume as well as on minimal cross-sectional area (A(min)) and intranasal distance to A(min) (D(min)) were studied. Compound 48/80 caused a dose-related decrease in nasal cavity volume and A(min) together with a variable increase in D(min). Maximal responses were seen at 90-120 min. Compound 48/80 was less effective in producing nasal congestion in conscious animals, which also had significantly larger basal nasal cavity volumes. These results demonstrate the utility of using acoustic rhinometry to measure parameters of nasal patency in dogs and suggest that this model may prove useful in studies of the actions of decongestant drugs.