The association of peri-operative scores, including frailty, with outcomes after unscheduled surgery.

Postoperative hospital stay is longer for frail, older patients, who are more likely to experience prolonged postoperative morbidity and reduced long-term survival. We recorded in-hospital mortality, morbidity and length of stay for 164 patients aged at least 65 years after unscheduled surgery. We evaluated pre-operative frailty with the 7-point Clinical Frailty Scale: 81 patients were 'not vulnerable' (frailty score 1-3) and 83 were 'vulnerable or frail' (frailty score ≧ 4), with mean (SD) ages of 74.7 (7.5) years vs. 79.4 (8.3) years, respectively, p < 0.001. Within 30 postoperative days 8/164 (5%) patients died, all with frailty scores ≧ 4, p = 0.007. Postoperative morbidity was less frequent in patients categorised as 'not vulnerable' on four out of the six days it was measured (days 3, 5, 8, 14, 23, 28). Median (IQR [range]) postoperative stay was 9 (6-18 [2-221]) days for patients with frailty scores 1-3, and 22 (12-33 [2-270]) days for patients with score ≧ 4, p < 0.001. Four variables independently associated with hospital discharge, hazard ratio (95%CI): E-POSSUM, 0.74 (0.60-0.92), p = 0.007; ASA 2, 0.35 (0.13-0.98), p = 0.046, ASA 3, 0.17 (0.06-0.47), p = 0.001 and ASA 4/5, 0.08 (0.02-0.28), p < 0.001; operative severity 'major +', 0.69 (0.41-1.08), p = 0.10 and the Surgical Outcome Risk Tool, 7.75 (0.81-74.40), p = 0.08.

Overexpression of miR-214-3p in esophageal squamous cancer cells enhances sensitivity to cisplatin by targeting survivin directly and indirectly through CUG-BP1.

Based on its marked overexpression in multiple malignancies and its roles in promoting cell survival and proliferation, survivin is an attractive candidate for targeted therapy. Toward this end, a detailed understanding of the mechanisms regulating survivin expression in different cancer cells will be critical. We have previously shown that the RNA-binding protein (RBP) CUG-BP1 is overexpressed in esophageal cancer cells and post-transcriptionally regulates survivin in these cells. The objective of this study was to investigate the role of microRNAs (miRs) in regulating survivin expression in esophageal cancer cells. Using miR expression profiling analysis, we found that miR-214-3p is one of the most markedly downregulated miRs in two esophageal squamous cancer cell lines compared with esophageal epithelial cells. Interestingly, using miR target prediction programs, both survivin and CUG-BP1 mRNA were found to contain potential binding sites for miR-214-3p. Forced expression of miR-214-3p in esophageal cancer cells leads to a decrease in the mRNA and protein levels of both survivin and CUG-BP1. This effect is due to decreased mRNA stability of both targets. By contrast, silencing miR-214-3p in esophageal epithelial cells leads to an increase in both survivin and CUG-BP1 mRNA and protein. To determine whether the observed effect of miR-214-3p on survivin expression was direct, mediated through CUG-BP1, or both, binding studies utilizing biotin pull-down assays and heterologous luciferase reporter constructs were performed. These demonstrated that the mRNA of survivin and CUG-BP1 each contain two functional miR-214-3p-binding sites as confirmed by mutational analysis. Finally, forced expression of miR-214-3p enhances the sensitivity of esophageal cancer cells to cisplatin-induced apoptosis. This effect is abrogated with rescue expression of survivin or CUG-BP1. These findings suggest that miR-214-3p acts as a tumor suppressor and that its downregulation contributes to chemoresistance in esophageal cancer cells by targeting both survivin and CUG-BP1.

Acute Influenza A infection induces bronchial hyper-responsiveness in mice.

This study aimed to determine whether the route of administration of methacholine (MCh) influenced the pattern of airway hyper-responsiveness (AHR) in mice. BALB/c mice were inoculated with a 50-microL volume containing 10(4.5)-pfu Influenza virus A/Mem/1/71(H3N1) or media. MCh responsiveness in vivo [inhaled (0.01-30 mg/mL), i.v. MCh (6-48 microg/min/kg)] and in vitro were measured at day 4 post-infection (D4) during acute lower respiratory infection (LRI) and following resolution of infection at day 20 (D20) using a low-frequency, forced oscillation technique. Inflammation was assessed in bronchoalveolar lavage fluid. Infected mice had pulmonary inflammation and heightened responsiveness to both inhaled (p<0.03) and intravenous (p<0.02) MCh on D4, but not on D20. In vitro responsiveness was not altered at either time point. Influenza A LRI results in AHR during acute infection associated with a marked inflammatory response and increased permeability of the alveolar-capillary barrier. These data suggest that intrinsic muscle properties are not altered but MCh has greater access to airway smooth muscle during acute infection.

Ovalbumin-sensitized mice are good models for airway hyperresponsiveness but not acute physiological responses to allergen inhalation.

BACKGROUND: Asthma is a chronic inflammatory disease that is characterized clinically by airway hyperresponsiveness (AHR) to bronchoconstricting agents. The physiological response of the asthmatic lung to inhaled allergen is often characterized by two distinct phases: an early-phase response (EPR) within the first hour following exposure that subsides and a late-phase response (LPR) that is more prolonged and may occur several hours later. Mouse models of asthma have become increasingly popular and should be designed to exhibit an EPR, LPR and AHR. OBJECTIVE: To determine whether a common model of asthma is capable of demonstrating an EPR, LPR and AHR. METHODS: BALB/c mice were sensitized to ovalbumin (OVA) and challenged with one or three OVA aerosols. Changes in lung mechanics in response to allergen inhalation were assessed using a modification of the low-frequency forced oscillation technique (LFOT). In order to assess AHR, changes in lung mechanics in response to aerosolized methacholine were assessed using LFOT. Inflammatory cell infiltration into the lung was measured via bronchoalveolar lavage (BAL). ELISAs were used to measure inflammatory cytokines in the BAL and levels of IgE in the serum. RESULTS: An EPR was only detectable after three OVA aerosols in approximately half of the mice studied. There was no evidence of an LPR despite a clear increase in cellular infiltration 6 h post-allergen challenge. AHR was present after a single OVA aerosol but not after three OVA aerosols. CONCLUSIONS: The lack of an LPR, limited EPR and the absence of a link between the LPR and AHR highlight the limitations of this mouse model as a complete model of the lung dysfunction associated with asthma.

Growth factors differentially regulate neuronal Cav channels via ERK-dependent signalling.

Voltage-gated calcium channels (Ca(v)) are tonically up-regulated via Ras/extracellular signal-regulated kinase (ERK) signalling in sensory neurones. However, the mechanisms underlying the specificity of cellular response to this pathway remain unclear. Neurotrophic factors are attractive candidates to be involved in this process as they are key regulators of ERK signalling and have important roles in neuronal survival, development and plasticity. Here, we report that in rat dorsal root ganglion neurones, endogenous nerve growth factor (NGF), glial derived neurotrophic factor (GDNF) and epidermal growth factor (EGF) are all involved in tonic ERK-dependent up-regulation of Ca(v) channels. Chronic (overnight) deprivation of growth factors inhibits total Ca(v) current according to developmental changes in expression of the cell surface receptors for NGF, GDNF and EGF. Whilst EGF specifically regulates transcriptional expression of Ca(v)s, NGF and GDNF also acutely modulate Ca(v) channels within a rapid ( approximately 10min) time-frame. These acute effects likely involve changes in the biophysical properties of Ca(v)s, including altered channel gating rather than changes in surface expression. Furthermore, NGF, GDNF and EGF differentially regulate specific populations of Ca(v)s. Thus, ERK-dependent regulation of Ca(v) activity provides an elegant and extremely flexible system with which to tailor calcium influx to discrete functional demands.

Suppression of the asthmatic phenotype by ultraviolet B-induced, antigen-specific regulatory cells.

BACKGROUND: Over recent decades, there has been a significant global increase in the prevalence of asthma, an inflammatory disease of the respiratory system. While ultraviolet radiation (UV) has been used successfully in the treatment of inflammatory conditions such as psoriasis, studies of UV-induced regulation of allergic respiratory responses have been rare, and have not analysed in vivo measurements of airway hyperresponsiveness (AHR) or the antigen specificity of the UV-induced effects. OBJECTIVE: To investigate the regulatory properties of erythemal ultraviolet B (UVB) irradiation of the skin and the induction of allergen-induced airway immunity in a murine asthma model, and to examine the mechanisms involved. METHODS: BALB/c mice were exposed to a single erythemal dose of UV 3 days before intraperitonial sensitization (day 0) and boost (day 14) with the antigen, ovalbumin (OVA). Airway-associated, asthma-like responses to aerosolized OVA at day 21 were analysed including (a) AHR measured in vivo, (b) OVA-specific proliferative responses and cytokine production by cells from the lung-draining lymph nodes (LDLN), and (c) inflammatory cells and cytokines in the bronchoalveolar lavage fluid. To determine UVB-induced mechanisms of regulation, LDLN cells from UVB irradiated, OVA-sensitized mice were adoptively transferred into naïve BALB/c mice that were subsequently sensitized and challenged with OVA, or a non-specific antigen. RESULTS: UVB irradiation of skin significantly suppressed AHR to methacholine and OVA-specific responses in the LDLN and in the lung compartment. Reduced OVA-specific responses by LDLN cells from both UVB irradiated mice and mice that received 5 x 10(6) LDLN cells from UVB irradiated, but not from non-irradiated, OVA-sensitized mice suggested that UVB-induced regulatory cells are responsible for many of the asthma-reducing effects of dorsal UVB exposure. CONCLUSION: UVB irradiation of skin suppresses AHR and cellular responses of the airways to respiratory allergens. Further, this study implicates UVB or its downstream mediators as a potential approach to reducing the severity of asthma.

Phosphorylation sites on calcium channel alpha1 and beta subunits regulate ERK-dependent modulation of neuronal N-type calcium channels.

Voltage-dependent calcium channels (VDCCs) in sensory neurones are tonically up-regulated via Ras/extracellular signal regulated kinase (ERK) signalling. The presence of putative ERK consensus sites within the intracellular loop linking domains I and II of neuronal N-type (Ca(v)2.2) calcium channels and all four neuronal calcium channel beta subunits (Ca(v)beta), suggests that Ca(v)2.2 and/or Ca(v)betas may be ERK-phosphorylated. Here we report that GST-Ca(v)2.2 I-II loop, and to a lesser extent Ca(v)beta1b-His(6), are substrates for ERK1/2 phosphorylation. Serine to alanine mutation of Ser-409 and/or Ser-447 on GST-Ca(v)2.2 I-II loop significantly reduced phosphorylation. Loss of Ser-447 reduced phosphorylation to a greater extent than mutation of Ser-409. Patch-clamp recordings from wild-type Ca(v)2.2,beta1b,alpha2delta1 versus mutant Ca(v)2.2(S447A) or Ca(v)2.2(S409A) channels revealed that mutation of either site significantly reduced current inhibition by UO126, a MEK (ERK kinase)-specific inhibitor that down-regulates ERK activity. However, no additive effect was observed by mutating both residues together, suggesting some functional redundancy between these sites. Mutation of both Ser-161 and Ser-348 on Ca(v)beta1b did not significantly reduce phosphorylation but did reduce UO126-induced current inhibition. Crucially, co-expression of Ca(v)2.2(S447A) with Ca(v)beta1b(S161,348A) had an additive effect, abolishing the action of UO126 on channel current, an effect not seen when Ca(v)beta1b(S161,348A) was co-expressed with Ca(v)2.2(S409A). Thus, Ser-447 on Ca(v)2.2 and Ser-161 and Ser-348 of Ca(v)beta1b appear to be both necessary and sufficient for ERK-dependent modulation of these channels. Together, our data strongly suggest that modulation of neuronal N-type VDCCs by ERK involves phosphorylation of Ca(v)2.2alpha1 and to a lesser extent possibly also Ca(v)beta subunits.

Cholinergic responsiveness of the individual airway after allergen instillation in sensitised pigs.

Allergen exposure of sensitised lungs produces bronchial hyperresponsiveness in vivo associated with airway inflammation and remodelling. It is unclear if hyperresponsiveness is also present in airways in vitro under similar conditions of drug provocation as carried out in vivo, and at different times after allergen-challenge. This study records responsiveness of individual airway segments to acetylcholine (ACh) in sensitised bronchi after instillation of allergen (ovalbumin, OA). Airway histology and sensitivity and maximum effects to ACh were recorded 1, 24 and 72 h and 1 week after OA. OA-instilled airways exhibited eosinophilia and epithelial proliferation. Physiological recordings showed no change in maximum contractions of airway segments to acetylcholine placed in the airway lumen except at 24 h where they were reduced. In contrast maximum contractions to ACh to the airway adventitia were reduced at all times except 1 week, with the greatest change occurring at 24 h. There were no changes in airway sensitivity to either route of ACh in OA-instilled airways but the difference in sensitivity to adventitial and lumenal ACh was reduced. Results show that allergen does not produce hyperresponsiveness at the airway wall but it may alter an interaction between airway smooth muscle and other structural components of the airway.

Primary human herpesvirus-6 and -7 infections, often coinciding, misdiagnosed as measles in children from a tropical region of Brazil.

We investigated primary human herpesvirus-6 and -7 (HHV-6, HHV-7) infections as a cause of rashes incorrectly diagnosed as measles in Brazilian children. Sera from 124 patients, aged 4 months to 17 years, from the states of Rio de Janeiro and Espirito Santo, in whom measles, rubella and parvovirus B19 infections had been excluded, were studied using indirect immunofluorescence antibody avidity tests; 38 (31%) had evidence of primary HHV-6 and/or HHV-7 infections. Twenty four children had primary HHV-6 infection, either recent or coincident with the rash, and similarly 31 had primary HHV-7 infection. Remarkably, almost half (17) of primary infections were dual HHV-6 and HHV-7 infections with the majority, 12 (71%), in children less than 1 year old. HHV-7 infection occurred earlier than previously reported, perhaps due to socioeconomic and tropical conditions in this region of Brazil, and thus coincided with the HHV-6 infections. This study also highlights the difficulties of diagnosing a rash illness on clinical grounds alone.

Relationship of airway narrowing, compliance, and cartilage in isolated bronchial segments.

Structural components of the airway wall may act to load airway smooth muscle and restrict airway narrowing. In this study, the effect of load on airway narrowing was investigated in pig isolated bronchial segments. In some bronchi, pieces of cartilage were removed by careful dissection. Airway narrowing was produced by maximum electrical field stimulation. An endoscope was used to record lumen narrowing. The compliance of the bronchial segments was determined from the cross-sectional area of the lumen and the transmural pressure. Airway narrowing and the velocity of airway narrowing were increased in cartilage-removed airways compared with intact control bronchi. Morphometric assessment of smooth muscle length showed greater muscle shortening to acetylcholine in cartilage-removed airways than in controls. Airway narrowing was positively correlated with airway compliance. Compliance and area of cartilage were negatively correlated. These results show that airway narrowing is increased in compliant airways and that cartilage significantly loads airway smooth muscle in whole bronchi.

The fragmented science of ball lightning (with comment).

All the apparent anomalies in ball lightning behaviour seem to result from electrochemical processes which arise at the surface of a wet air plasma. The structure and stability of an established lightning ball are maintained by these processes and the ball operates as a thermochemical heat pump powered by the electric field of a thunderstorm. Movements result from asymmetries in the various fields which control the structure. In addition to electric, electromagnetic and gravitational fields, temperature, pressure and compositional gradients can be involved. Electrochemistry provides a framework within which specific properties can be considered using better developed or more appropriate disciplines. Several commonly made assumptions and approximations are identified which can be invalid under the specific conditions which favour ball lightning stability. If any of these limitations is ignored, seriously misleading conclusions may result. The range of power associated with lightning balls is ill defined but may vary continuously between that of globes which lack a bright centre and that of normal lightning. Our failure to contain plasmas electrochemically for more than a few seconds probably reflects our inability to balance (or even measure) the various fields which govern a ball's stability. All the fields may need to be controlled before electrochemistry can usefully be employed to contain plasmas.

Functional overlap of IP(3)- and cADP-ribose-sensitive calcium stores in guinea pig myenteric neurons.

In myenteric neurons two different receptor subtypes govern the intracellular Ca(2+) stores: the inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R) and the ryanodine receptor (RyR). Their degree of functional overlap was determined by examining Ca(2+) release in these cells through both superfusion techniques and intracellular microinjection. Microinjection of IP(3) (50 microM) and cADP-ribose (cADPr, 50 microM), specific ligands for the IP(3)R and RyR, respectively, demonstrated mobilization of intracellular Ca(2+) stores. Perfusion with cinnarizine (50 microM) or dantrolene (10 microM), antagonists of the IP(3)R and RyR, respectively, eliminated the Ca(2+) response to microinjected IP(3) and cADPr. Superfusion of the neurons with 100 microM ATP, an IP(3)-mediated Ca(2+)-mobilizing agonist, caused intracellular Ca(2+) increments, which were antagonized by cinnarizine, and the RyR antagonists dantrolene, procaine (5 mM), and ryanodine (1 microM). Caffeine (10 mM) was applied repetitively in Ca(2+)-free conditions to deplete RyR-sensitive stores; subsequent perfusion with ATP demonstrated a Ca(2+) response. Conversely, caffeine caused a Ca(2+) response after repetitive ATP exposures. The internal Ca(2+) stores of myenteric neurons are governed by two receptor subtypes, IP(3)R and RyR, which share partial functional overlap.

Use of immunoglobulin G antibody avidity for differentiation of primary human herpesvirus 6 and 7 infections.

A human herpesvirus 7 (HHV-7) indirect immunofluorescence antibody avidity test was developed and used with an existing human herpesvirus 6 (HHV-6) antibody avidity test to detect and distinguish low-avidity antibodies to HHV-6 and HHV-7 and hence the respective primary infections. With sera from 269 British children aged 0 to 179 weeks, the tests showed that most (10 of 98 serum samples [13%]) HHV-6 low-avidity antibody was found in the first year of life, whereas for HHV-7, most (18 of 101 serum samples [20%]) HHV-7 low-avidity antibody was found in the second year of life. Five children had low-avidity antibodies to both viruses. Of nine Japanese children with previously serologically proven primary HHV-6 or HHV-7 infections, eight had low-avidity antibody only to the relevant virus, but one child had low-avidity antibodies to HHV-6 and HHV-7. The avidity tests were applied to five British children and further proof of viral infection was sought by the detection of specific DNA in serum or plasma, and saliva or cerebrospinal fluid. In two children who had low-avidity antibody to HHV-7 but who were seronegative for HHV-6, only HHV-7 was found. Both viruses were detected in one child with low-avidity HHV-7 antibody and high-avidity HHV-6 antibody. In two children with low-avidity antibodies to both viruses, HHV-6 and HHV-7 DNAs were found, confirming dual primary infections and excluding antibody cross-reactivity.

Cholinergic stimulation of rat acinar cells increases c-fos and c-jun expression via a mitogen-activated protein kinase-dependent pathway.

Acetylcholine release from cholinergic neurons regulates pancreatic exocrine function through pathways that are still under investigation. Pancreatic AR42J acinar cells were studied to determine intracellular calcium ([Ca(2+)](i)) release, enzyme activation, and gene expression in response to the acetylcholine analog carbachol (CCh). CCh stimulated dose-dependent increases in [Ca(2+)](i) that were inhibited by atropine and by specific inhibitors to the muscarinic receptor subtypes m1 and m3. Polymerase chain reaction analysis was performed, which sequenced products corresponding to the m1 and m3 receptor subtypes but not the m2 subtype. CCh also stimulated mitogen-activated protein kinase activity. CCh induced time-and dose-dependent increases in the c-fos and c-jun early-response genes, which were blocked by m1 and m3 inhibition but not by m2 inhibition.

Physiological responses of the airway wall and lung in hyperresponsive pigs.

Airway hyperresponsiveness (AHR) might be driven by mechanisms inherent to the airway wall, and/or by factors arising from outside the airways. A porcine model of allergen-induced AHR was utilized to investigate physiological responses in intact airways in vitro and their contribution to responsiveness in vivo. Responsiveness to acetylcholine (ACh) was measured in eight ovalbumin (OA)-sensitized/challenged pigs (tests) and eight saline-challenged controls. In vivo responsiveness to ACh was determined from pulmonary resistance (RL). In vitro responsiveness to ACh was determined from airway pressure in isovolumic bronchial segments, after exposure via the adventitial or the luminal surface. Test pigs had lung (255+/-26% increase in RL, p<0.0001) and skin responses to OA, and AHR to ACh (p<0.0001). In vitro, test bronchi were less sensitive than controls to ACh applied to the airway adventitia (negative log of the ACh concentration producing half the maximum response (pD2)=4.18 and 4.58 respectively, p<0.01), but not the lumen. Test bronchi had an increased amount of smooth muscle normalized for airway size versus controls (p<0.05). Maximum responses to lumenal ACh in vitro showed a weak positive correlation with maximum changes to ACh in vivo (r=0.599, p=0.05). This study concludes that the effect of antigen challenge on bronchial responsiveness varies with the route of exposure to acetylcholine. In vitro responses to lumenal acetylcholine are increased despite a possible reduction in responsiveness of airway smooth muscle. Responsiveness of the bronchial wall only partially explains responsiveness of the lungs in vivo.

Cholinergic intrapancreatic neurons induce Ca²+ signaling and early-response gene expression in pancreatic acinar cells.

Pancreatic exocrine function has been demonstrated to be under neuronal regulation. The pathways responsible for this effect, and the long-term consequences of such interactions, are incompletely described. The effects of neuronal depolarization on pancreatic acinar cells were studied to determine whether calcium signaling and c-fos expression were activated. In pancreatic lobules, which contain both neurons and acinar cells, agonists that selectively stimulated neurons increased intracellular calcium in acinar cells. Depolarization also led to the expression of c-fos protein in 24% +/- 4% of the acinar cells. In AR42J pancreatic acinar cells, cholinergic stimulation demonstrated an average increase of 398 +/- 19 nmol/L in intracellular calcium levels, and induced c-fos expression that was time and dose dependent. The data indicate that intrapancreatic neurons induce Ca²+ signaling and early-response gene expression in pancreatic acinar cells.

ATP induces c-fos expression in C6 glioma cells by activation of P(2Y) receptors.

BACKGROUND: Extracellular ATP functions in the enteric nervous system as a neurotransmitter, and recent evidence suggests ATP may regulate development through effects on cellular proliferation. METHODS: The action of ATP at purinoceptors and the role of second messenger pathways in c-fos mRNA expression in C6 glioma cells were investigated using the techniques of Northern and Western blotting. RESULTS: Treatment of C6 cells with ATP caused a time- and dose-dependent increase in c-fos expression. The rank order of agonist potency was ATP = ADP > gammasATP > alphabetaATP > betagammaATP > AMP = UTP. The ATP-induced c-fos increment was inhibited by three P(2Y) receptor antagonists-suramin, reactive blue, and DIDS-by 99+/-3, 89+/-7, and 61+/-14%, respectively. The ATP-stimulated c-fos expression was attenuated by phospholipase C inhibitor (U73122), protein kinase C (PKC) down-regulation (4alpha-phorbol 12-myristate 13-acetate and chelerythrine), mitogen-activated protein (MAP) kinase inhibition (apigenin), an inhibitor of MAP kinase kinase (PD98059), down-regulation of adenylate cyclase (SQ22536), and inhibition of type II protein kinase A (8-(4-chlorophenylthio)adenosine-3',5'-cyclic monophosphorothioate), but was not affected by inhibition of type I protein kinase A (8-bromoadenosine-3',5'-cyclic monophosphorothioate) and inhibitors of calmodulin kinase (KN93 and KN62). Phosphorylated MAP kinase was increased in cells exposed to ATP. This effect was suppressed by chelerythrine. CONCLUSIONS: These studies demonstrate that ATP-induced c-fos mRNA expression is under multifactorial regulation.

Bradykinin-induced airway constriction in guinea-pigs: role of leukotriene D(4).

Tachykinins (TK) have been implicated in both bradykinin-(BK) and hyperpnea-induced broncho-constriction (HIB) in the guinea-pig. However, TKs appear to have an indirect effect in HIB by releasing leukotriene (LT)D(4). We postulated that BK may cause bronchoconstriction through a cascade involving TK and LTD(4). We examined the role of TK and LTD(4)in BK-induced bronchoconstriction in ventilated Hartley guinea-pigs. Respiratory resistance (R(rs)) was monitored for 2 h following insufflation of BK (150 nM). Animals were pretreated with propranolol, then with either neurokinin (NK)1 (CP-99,994)+NK2 (SR-48,968) receptor antagonists or pranlukast (90 microg or 900 microg), an LTD(4)antagonist. Control animals received no pretreatment. BK-induced bronchoconstriction was significantly lower in NK1/NK2 (128%+/-6% baseline R(rs)SEM) and pranlukast (90 microg; 205+/-22, 900 microg; 169+/-20) animals compared to controls (284+/-22), P<0.0001 ANOVA. Bile from control and saline challenged animals was analysed for LTD(4)by HPLC and radio-immunoassay. However, LTD(4)excretion rate showed no significant difference over a 2-h collection period following insufflation of either BK or saline, respectively; baseline =2.5 pmol/h+/-0.6 SEM vs. 2.3+/-0.2, 0-1 h=2.8+/-0.7 vs. 2.0+/-0.6, 1-2 h=2.3+/-0.6 vs. 1.7+/-0.7. We conclude that BK-induced bronchoconstriction is mediated in part through the release of both TK and LTD(4), but the latter is released in insufficient quantities to be detectable by biliary analysis.

Pulmonary vascular congestion selectively potentiates airway responsiveness in piglets.

The influence of pulmonary vascular congestion on the response of the airways and lung tissue to low doses of inhaled methacholine (MCh) was studied by inflating a balloon catheter in the left atrium of the heart in six piglets, with an additional five piglets serving as control animals. Congestion alone resulted in small increased in baseline airway (Raw) (14.6 +/- 3.7%) and tissue (Rti) resistance (8. 1 +/- 6.5%). Low-dose inhaled MCh (0.3 mg/ml) increased Raw and Rti in the control group by 10.8 +/- 10.3% and 42.2 +/- 29.5%, respectively. The increase in Raw with MCh in the presence of vascular engorgement was significantly greater (67.8 +/- 18.9%) but the increase in Rti (38.1 +/- 13.2%) was similar to that seen in the control group. Morphometric measurements were performed on transverse sections of large and small airways from nine additional piglets (three congested only, three MCh only, and three congestion plus MCh). The thickness of the inner airway wall was similar in all groups. Compared with MCh only piglets, the thickness of the outer airway wall (between the outer border of the smooth muscle and the surrounding lung parenchyma) was increased (p < 0.05) in engorged only and engorged plus MCh piglets. Compared with MCh only and engorgement only, the amount of airway smooth muscle shortening was greater (p < 0.05) in all airway size groups in piglets that underwent engorgement plus MCh challenge. The results of this study demonstrate that pulmonary vascular engorgement, induced by increased left atrial pressure, selectively enhances the airway, but not the parenchymal, response to inhaled MCh. These changes are associated with increased thickness of the outer airway wall in response to vascular congestion, suggesting that uncoupling of the mechanical interdependence between the airway smooth muscle and the lung parenchyma may have occurred. Mechanical uncoupling may reduce the load opposing smooth muscle shortening resulting in increased airway narrowing in response to low doses of inhaled methacholine.

Randomized trial comparing a radially expandable needle system with cutting trocars.

Sharp trocar insertion for laparoscopic procedures carries with it increased risk for vascular and visceral complications and incisional hernia. In a trial, which randomized 87 patients to treatment with either sharp trocars or a radially expanding needle system with blunt dilator, results showed that with the latter system there was statistically improved patient assessment of pain, a lower complications rate, and shorter procedure time. In the group of patients randomized to treatment with conventional trocars, there were a total of six instrument-related adverse events (6/42): four cases (five incidences) of abdominal wall injuries and one small bowel perforation caused by a Veress needle. Of the 45 patients randomized to the blunt dilator/cannula treatment, there was one adverse event (1/45) that was unrelated to the blunt dilator/cannula system: Veress needle injury to abdominal vasculature. The radially expanding access system demonstrates statistically improved patient postoperative comfort and improved patient safety.