Expanded HILUS Trial: A Pooled Analysis of Risk Factors for Toxicity From Stereotactic Body Radiation Therapy of Central and Ultracentral Lung Tumors

PURPOSE

Stereotactic body radiation therapy for tumors near the central airways implies high-grade toxic effects, as concluded from the HILUS trial. However, the small sample size and relatively few events limited the statistical power of the study. We therefore pooled data from the prospective HILUS trial with retrospective data from patients in the Nordic countries treated outside the prospective study to evaluate toxicity and risk factors for high-grade toxic effects.

METHODS AND MATERIALS

All patients were treated with 56 Gy in 8 fractions. Tumors within 2 cm of the trachea, the mainstem bronchi, the intermediate bronchus, or the lobar bronchi were included. The primary endpoint was toxicity, and the secondary endpoints were local control and overall survival. Clinical and dosimetric risk factors were analyzed for treatment-related fatal toxicity in univariable and multivariable Cox regression analyses.

RESULTS

Of 230 patients evaluated, grade 5 toxicity developed in 30 patients (13%), of whom 20 patients had fatal bronchopulmonary bleeding. The multivariable analysis revealed tumor compression of the tracheobronchial tree and maximum dose to the mainstem or intermediate bronchus as significant risk factors for grade 5 bleeding and grade 5 toxicity. The 3-year local control and overall survival rates were 84% (95% CI, 80%-90%) and 40% (95% CI, 34%-47%), respectively.

CONCLUSIONS

Tumor compression of the tracheobronchial tree and high maximum dose to the mainstem or intermediate bronchus increase the risk of fatal toxicity after stereotactic body radiation therapy in 8 fractions for central lung tumors. Similar dose constraints should be applied to the intermediate bronchus as to the mainstem bronchi.

First observation of 28O

Subjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Z ratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10-21 s), provide the most stringent tests of modern nuclear-structure theories. Here we report on the first observation of 28O and 27O through their decay into 24O and four and three neutrons, respectively. The 28O nucleus is of particular interest as, with the Z = 8 and N = 20 magic numbers1,2, it is expected in the standard shell-model picture of nuclear structure to be one of a relatively small number of so-called 'doubly magic' nuclei. Both 27O and 28O were found to exist as narrow, low-lying resonances and their decay energies are compared here to the results of sophisticated theoretical modelling, including a large-scale shell-model calculation and a newly developed statistical approach. In both cases, the underlying nuclear interactions were derived from effective field theories of quantum chromodynamics. Finally, it is shown that the cross-section for the production of 28O from a 29F beam is consistent with it not exhibiting a closed N = 20 shell structure.

Left atrial reservoir strain predicts ischemic stroke after coronary artery bypass grafting independent of postoperative atrial fibrillation

Background

Patients undergoing coronary artery bypass grafting (CABG) surgery face an elevated long-term risk of ischemic stroke.

Left atrial (LA) mechanics including LA strain are known to predict both stroke and atrial fibrillation in other populations. Evidence is conflicting with regards to the clinical significance of postoperative atrial fibrillation (POAF) and its role in the association between LA mechanics and ischemic stroke is unclear.

Purpose

The aim of the study was to investigate the association between LA reservoir strain and long-term ischemic stroke in patients undergoing CABG surgery and whether the presence of POAF modified this relationship.

Methods

Patients undergoing isolated CABG were included from 2006–2011 as part of a retrospective cohort study. Echocardiography was performed prior to surgery. We included patients with available LA reservoir strain measurements, while patients with known atrial fibrillation and moderate to severe valvular disease were excluded. The primary endpoint was ischemic stroke. The association between LA reservoir strain and ischemic stroke was investigated in uni- and multivariable Cox proportional hazards regression models including adjustment for POAF. Poisson regression was used to create a restricted cubic spline model of the continuous association between LA reservoir strain and risk of ischemic stroke.

Results

We included 542 patients in the analysis. Mean age was 67.3±8.9 years, 89 (16.4%) were female, and median EuroSCORE II was 1.31 (IQR 0.93–1.96). Patients with LA reservoir strain <27.2% (median) were older, more likely to have diabetes, and had a higher EuroSCORE II.

In total, 96 patients (17.7%) developed POAF. During a median follow-up period of 3.7 years (IQR 2.7–4.8 years), 21 (3.9%) patients experienced ischemic stroke. In univariable modeling, LA reservoir strain was significantly associated with ischemic stroke (HR 1.10 (95% CI 1.03–1.18, p=0.003) per 1% absolute decrease). After adjustment for EuroSCORE II, LA volume index (LAVi) and prior stroke, LA reservoir strain remained a significant predictor of ischemic stroke (HR 1.09 (95% CI 1.02–1.17, p=0.011) per 1% absolute decrease and HR 4.24 (95% CI 1.37–13.10, p=0.012) for < vs. >median). Adding POAF as a covariate did not alter the significance of LA reservoir strain in the model. In addition, POAF did not modify the association between LA reservoir strain and POAF (p for interaction = 0.07). The association between LA reservoir strain and ischemic stroke persisted in multiple sensitivity analyses including restricting the analysis to patients with normal left atrial volumes (LAVi <34 ml/m2), patients without POAF, and when excluding patients who developed atrial fibrillation during follow-up.

Conclusion

In patients undergoing CABG, LA reservoir strain was an independent long-term predictor of ischemic stroke. The predictive value of LA reservoir strain was unaffected by the presence of POAF.

Funding Acknowledgement

Type of funding sources: None.

Prognostic value of layer-specific global longitudinal strain in patients undergoing coronary artery bypass grafting

Background

Recent improvements in speckle tracking echocardiography have made sectionalized quantification of layer-specific global longitudinal strain (GLS) possible. Prior studies have reported prognostic value of GLS in several cardiac diseases, however, the use of layer-specific strain has not been investigated in patients undergoing coronary artery bypass grafting (CABG).

Purpose

To determine the prognostic value of layer-specific GLS for predicting all-cause mortality after CABG.

Methods

In this retrospective cohort study, consecutive patients undergoing isolated CABG between 2006 and 2011 were included. The patients were followed through nation-wide registries for the endpoint of all-cause mortality. Multivariable Cox regression models adjusted for clinical and echocardiographic baseline characteristics were used to assess the association between layer-specific GLS and all-cause mortality. Cumulative survival was stratified by clinical age and gender-dependent cut-off values for the layer-specific GLS, which was obtained from a large healthy population study.

Results

Of 641 patients included (mean age 67 years, 84% male), 70 (10.9%) died during follow-up (median 3.8 years [IQR: 2.7; 4.9 years]). Patients who died during follow-up were significantly older (71 years vs. 67 years, P = <0.001) and had a lower LVEF (46% vs. 51% P = <0.001). Endocardial GLS (GLSendo) (−14.2% vs. −16.3%, P<0.001), whole wall GLS (−12.1% vs. −13.9%, P<0.001), and epicardial GLS (GLSepi) (−10.6% vs. −12.2%, P<0.001) were all reduced in patients who died during follow-up, and patients with GLS below cut-off had a more than two-fold increased risk of all-cause mortality (Figure 1). The risk of dying increased linearly with decreasing absolute GLS for all layers (p<0.0002 for all layers), (Figure 2). In multivariable models, all layer-specific strain parameters remained significantly associated with all-cause mortality; GLSepi: HR=1.14 (1.05–1.23), p=0.002; GLS: HR=1.12 (1.04–1.20), p=0.002; GLSendo: HR=1.09 (1.03–1.16), p=0.003, per 1% absolute decrease. However, only GLSepi remained significantly associated with mortality when also adjusting for echocardiographic parameters (GLSepi: HR=1.12 (1.00–1.25), p=0.049, per 1% absolute decrease) and separately also after adjusting for the EuroScore II (GLSepi: HR=1.09 (1.00–1.18), p=0.043, per 1% absolute decrease).

Conclusion

Layer-specific GLS is an independent prognosticator of all-cause mortality after CABG. In multivariable models, GLSepi provided significant prognostic value after adjusting for echocardiographic parameters and EuroScore II.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Research grant from Herlev & Gentofte University Hospital's internal research funds. Figure 1. Kaplan-Meier survival estimatesFigure 2. Incidence rate of all-cause mortality

Prognostic utility of early systolic lengthening by speckle tracking in patients undergoing coronary artery bypass graft

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Independent Research Fund Denmark

Background

Early systolic lengthening (ESL), a paradoxical stretch of myocardial fibers, has been linked to myocardial viability and contractile dysfunction. We assessed the long-term prognostic potential of ESL in coronary artery bypass graft (CABG) patients.

Methods

We retrospectively included patients (n = 709; mean age 68 years; 85% men) who underwent speckle tracking echocardiography (median 15 days) prior to CABG. Endpoints were cardiovascular death (CVD) and all-cause mortality. We assessed amplitude of ESL (%), defined as peak positive strain, and duration of ESL (ms), determined as time from Q-wave on the ECG to peak positive strain. We applied Cox proportional hazards models adjusted for the clinical risk tool, EuroSCORE II.

Results

During median follow-up of 3.8 years [IQR 2.7 to 4.9 years], 45 (6%) experienced CVD and 80 (11%) died. In survival analyses adjusted for EuroSCORE II, amplitude of ESL was associated with CVD (HR 1.37 [95%CI 1.13 to 1.66], P = 0.001) and all-cause mortality (HR 1.31 [95%CI 1.13 to 1.54], P = 0.001). Similar findings applied to duration of ESL and CVD (HR 1.17 [95%CI 1.08 to 1.26], P < 0.001) and all-cause mortality (HR 1.14 [95%CI 1.07 to 1.21], P < 0.001). The prognostic value of ESL amplitude was modified by sex (P interaction < 0.05), such that it was greater in women for both endpoints (Figure 1A-B). When adding ESL duration to EuroSCORE II, the net reclassification index improved significantly for both CVD and all-cause mortality.

Conclusions

Assessment of ESL provides independent and incremental prognostic information in addition to the EuroSCORE II for CVD and all-cause mortality in CABG patients. The prognostic value was greater in women.

Abstract Figure. Prognostic value of ESL amplitude by sex

The Impact of a Community Resource Navigator Program on Patient Trust

BACKGROUND

Addressing patients' nonmedical needs has become a focal point in primary care research and practice. Programs such as the Center for Patient Partnerships' Community Resource Navigator Program address social determinants of health by connecting participants to community-based resources in an effort to ameliorate unmet social needs.

METHODS

Twenty-six interviews were conducted with program participants to assess improvements in social needs and trust with the health care system as a result of the program.

RESULTS

Program participants reported increased trust in their provider or health system, improved health, and confidence in self-advocacy.

DISCUSSION

Findings suggest that in addition to providing crucial support to address participants' unmet social needs, navigation programs have the added benefit of enhancing their relationship with the clinic and health system.

Extending the Southern Shore of the Island of Inversion to ^{28}F

Detailed spectroscopy of the neutron-unbound nucleus ^{28}F has been performed for the first time following proton/neutron removal from ^{29}Ne/^{29}F beams at energies around 230  MeV/nucleon. The invariant-mass spectra were reconstructed for both the ^{27}F^{(*)}+n and ^{26}F^{(*)}+2n coincidences and revealed a series of well-defined resonances. A near-threshold state was observed in both reactions and is identified as the ^{28}F ground state, with S_{n}(^{28}F)=-199(6)  keV, while analysis of the 2n decay channel allowed a considerably improved S_{n}(^{27}F)=1620(60)  keV to be deduced. Comparison with shell-model predictions and eikonal-model reaction calculations have allowed spin-parity assignments to be proposed for some of the lower-lying levels of ^{28}F. Importantly, in the case of the ground state, the reconstructed ^{27}F+n momentum distribution following neutron removal from ^{29}F indicates that it arises mainly from the 1p_{3/2} neutron intruder configuration. This demonstrates that the island of inversion around N=20 includes ^{28}F, and most probably ^{29}F, and suggests that ^{28}O is not doubly magic.

1096Diastolic myocardial dysfunction by tissue doppler imaging predicts outcome following isolated coronary artery bypass grafting

Background

Myocardial tissue velocities by tissue Doppler imaging (TDI) have proven superior predictors of outcome to left ventricular ejection fraction (LVEF) in ischemic heart disease, with early diastolic myocardial relaxation velocity (e') being an early sign of LV dysfunction in the ischemic cascade.

Purpose

We hypothesized that e' predicts outcome after coronary artery bypass grafting (CABG).

Methods

We included patients treated with isolated CABG (n=679). Before surgery, all patients had an echocardiogram performed with TDI to measure tissue velocities: systolic (s'), e' and late diastolic (a'). Endpoint was all-cause mortality retrieved from national registries. We performed Cox regressions and C-statistics. Net reclassification index was used to test improvement of EuroSCOREII.

Results

Of 679 patients, 79 (n=12%) died during follow-up (median: 3.8 years (IQR: 2.8; 5.0y). Follow-up was 100%. Mean age was 68 years, LVEF 50%, and 86% were male. All tissue velocities were univariable predictors of outcome (s': HR=1.46 [1.21; 1.78], p<0.001; e': HR=1.55 [1.33; 1.81], p<0.001; a': HR=1.19 [1.06; 1.33], p=0.004, per 1cm/s decrease for all). Overall, e' provided the highest C-statistics of all the tissue velocities (c-stat=0.69). In multivariable adjustments, e' remained an independent predictor after adjusting for clinical, biochemical and echocardiographic confounders (HR=1.24 [1.03; 1.49], p=0.022, per 1cm/s decrease). LVEF <40% modified the relationship between e' and outcome, so e' did not predict outcome in these patients (p for interaction = 0.013). However, e' was an independent predictor after multivariable adjustments in patients with LVEF >40% (HR=1.39 [1.11; 1.74], p=0.005, per 1cm/s decrease). When split by the median (−4.95cm/s), patients in the lowest group had a 3-fold increased risk of death (HR=3.31 [1.98; 5.56], p<0.001) compared to patients in the highest group (figure).

The e' improved the net reclassification improvement index when added to EuroSCOREII, with a net reclassification of 39%.

Conclusion

After CABG, e' is a strong predictor of all-cause mortality and improves the predictive value of the established prediction model, the EuroSCOREII. We identified a possible effect modifier in LVEF, such that e' was a strong predictor in patients with LVEF >40% and not when LVEF is below 40%.

P4628A multiple biomarker approach for risk assessment after ST-segment elevation myocardial infarction

Background

Several biomarkers independently predict outcome following ST-segment elevation myocardial infarction (STEMI). We hypothesized that combining information from multiple circulating biomarkers with numerous pathophysiological pathways may improve biomarker risk stratification following a STEMI.

Method

This was a prospective study of 735 patients with STEMI treated with primary percutaneous coronary intervention. Seventeen biomarkers were drawn before revascularization, including adrenalin, noradrenalin, C-reactive protein (CRP), neutrophil gelatinase-associated lipocalin (NGAL), pro-atrial natriuretic peptide (pro-ANP), alfa-defensin, adiponectin, troponin I, hemoglobin, thrombocyte, and total leukocyte count. The primary outcome was a composite of cardiovascular death or heart failure (CVD/HF) identified by national registries. In the effort to identify the best model, the population was randomly split into two equally sized groups, a derivation cohort and a validation cohort. We used classification and regression tree (CART) analysis to develop a risk model. The identified risk model was hereafter applied to the whole cohort.

Results

Mean age was 63 years, 74% were male and 33% had hypertension. During a median follow-up time of 5.0 years (3.2; 5.0), we observed 185 primary events. After including all biomarkers in the initial model, the CART analysis created a risk model including pro-ANP, NGAL, and CRP (Figure 1a). The risk of CVD/HF increased incrementally with increasing risk group (Figure 1b). The risk remained significantly higher in groups 3 and 4 after multivariable adjustments (hazard ratio (HR)=3.38 [95% confidence interval (CI): 1.60; 7.16] p=0.001 and HR=6.55 [95% CI: 2.73; 15.76] p<0.001, respectively) when compared with group 1.

Figure 1

Conclusion

We developed a risk model based on multiple biomarkers (NGAL, CRP, and pro-ANP) determined from a CART analysis which may ease risk stratification after STEMI.

Acknowledgement/Funding

Sif Rasmussen received a scholarship grant from Herlev & Gentofte Hospital and the P. Carl Petersens Fond during preparation of this manuscript.

Potassium-induced decrease in cytosolic Na+ alleviates deleterious effects of salt stress on wheat (Triticum aestivum L.)

Accumulation of NaCl in soil causes osmotic stress in plants, and sodium (Na⁺ ) and chloride (Cl^- ) cause ion toxicity, but also reduce the potassium (K⁺ ) uptake by plant roots and stimulate the K⁺ efflux through the cell membrane. Thus, decreased K⁺ /Na⁺ ratio in plant tissue lead us to hypothesise that elevated levels of K⁺ in nutrient medium enhance this ratio in plant tissue and cytosol to improve enzyme activation, osmoregulation and charge balance. In this study, wheat was cultivated at different concentrations of K⁺ (2.2, 4.4 or 8.8 mm) with or without salinity (1, 60 or 120 mm NaCl) and the effects on growth, root and shoot Na⁺ and K⁺ distribution and grain yield were determined. Also, the cytosolic Na⁺ concentration was investigated, as well as photosynthesis rate and water potential. Salinity reduced fresh weight of both shoots and roots and dry weight of roots. The grain yield was significantly reduced under Na⁺ stress and improved with elevated K⁺ fertilisation. Elevated K⁺ level during cultivation prevented the accumulation of Na⁺ into the cytosol of both shoot and root protoplasts. Wheat growth at vegetative stage was transiently reduced at the highest K⁺ concentration, perhaps due to plants' efforts to overcome a high solute concentration in the plant tissue, nevertheless grain yield was increased at both K⁺ levels. In conclusion, a moderately elevated K⁺ application to wheat seedlings reduces tissue as well as cytosolic Na⁺ concentration and enhances wheat growth and grain yield by mitigating the deleterious effects of Na⁺ toxicity.

Radiation-induced brachial plexus toxicity after SBRT of apically located lung lesions

Purpose: To evaluate the rate and dose response of brachial plexus toxicity post stereotactic body radiation therapy (SBRT) of apically situated lung lesions. Material/methods: We retrospectively identified all patients with apically located tumors, defined by the epicenter of the tumor being located superiorly to the aortic arch, and treated with SBRT between 2008 and 2013. Patients with a shorter follow-up than 6 months were excluded. Primary aim was to evaluate radiation-induced brachial plexopathy (RIBP). Dose to the plexus was assessed by a retrospective delineation of the brachial plexus on the CT used for treatment planning. Then, D_max, D_0.1cc, D_1cc and D_3.0cc of the brachial plexus were collected from the dose-volume histograms (DVH) and recalculated to the biologically effective dose (BED) using α/β = 3 Gy. A normal tissue complication probability (NTCP) model, based on four different dose-volume parameters (BED_3,max, BED_3,0.1cc, BED_3,1.0cc, BED_3,3.0cc) was fitted to the data. Results: Fifty-two patients with 56 apically located tumors were identified. Median prescription dose per fraction was 15 Gy (range 6-17) and median number of fractions was 3 (3-10). With a median follow-up of 30 months (6.1-72) seven patients experienced maximum grade 2 (scored 3 times) or 3 (scored 4 times) RIBP after a median of 8.7 months (range 4.0-31). Three patients had combined symptoms with pain, sensory and motor affection and four patients had isolated pain. Median BED_3,max for the patients experiencing RIBP was 381 Gy (range 30-524) versus BED_3,max of 34 Gy (range 0.10-483) for the patients without RIBP. The NTCP models showed a very high predictive ability (area under the receiver operating characteristic curve (AUC) 0.80-0.88). Conclusion: SBRT of apically located lung lesions may cause severe neurological symptoms; for a three-fraction treatment, we suggest that the maximum dose to the plexus should be kept ≤30 Gy (130 Gy BED₃).

Strong Neutron Pairing in core+4n Nuclei

The emission of neutron pairs from the neutron-rich N=12 isotones ^{18}C and ^{20}O has been studied by high-energy nucleon knockout from ^{19}N and ^{21}O secondary beams, populating unbound states of the two isotones up to 15 MeV above their two-neutron emission thresholds. The analysis of triple fragment-n-n correlations shows that the decay ^{19}N(-1p)^{18}C^{*}→^{16}C+n+n is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a ^{14}C core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay ^{21}O(-1n)^{20}O^{*}→^{18}O+n+n, attributed to its formation through the knockout of a deeply bound neutron that breaks the ^{16}O core and reduces the number of pairs.

Quasifree (p, 2p) Reactions on Oxygen Isotopes: Observation of Isospin Independence of the Reduced Single-Particle Strength

Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure of stable and exotic oxygen isotopes at the R^{3}B/LAND setup with incident beam energies in the range of 300-450  MeV/u. The oxygen isotopic chain offers a large variation of separation energies that allows for a quantitative understanding of single-particle strength with changing isospin asymmetry. Quasifree knockout reactions provide a complementary approach to intermediate-energy one-nucleon removal reactions. Inclusive cross sections for quasifree knockout reactions of the type ^{A}O(p,2p)^{A-1}N have been determined and compared to calculations based on the eikonal reaction theory. The reduction factors for the single-particle strength with respect to the independent-particle model were obtained and compared to state-of-the-art ab initio predictions. The results do not show any significant dependence on proton-neutron asymmetry.

High-precision measurement of isotopic fission yields of 236U*

We report on the second SOFIA experiment, dedicated to the fission yields of 236U*, analog to 235U(n,f). The measurement is based on the inverse kinematics method, using a relativistic, secondary beam of 236U. Both fission fragments are identified in mass and charge in the SOFIA recoil spectrometer. The obtained isotopic yields are compared with existing spectroscopy measurements and the elemental yields are used to discuss the treatment of the even-odd effect with energy in nuclear data libraries.

Integrating Medical-Dental Care for Diabetic Patients: Qualitative Assessment of Provider Perspectives

Globally, periodontal disease and diabetes have achieved epidemic proportions and have become a top health care priority. Mutual bidirectional exacerbation of these conditions is promoting creation of cross-disciplinary integrated care delivery (ICD) models that bridge the traditionally siloed health care domains of dentistry and medicine. By engaging focus groups inclusive of both medical and dental providers and one-on-one interviews, this qualitative study investigated provider knowledgeability, receptiveness, and readiness to engage ICD and sought input from the medical-dental primary care practitioner participants on perceived opportunities, benefits, and challenges to achieving ICD models for patients with diabetes/prediabetes. Statewide regional representation and inclusivity of diverse practice settings were emphasized in soliciting participants. Thematic analysis of focus group and interview transcripts was undertaken to establish current state of the art, gauge receptivity to alternative ICD models, and seek insights from practitioners surrounding opportunities and barriers to ICD achievement. Forty providers participated, and thematic analyses achieved saturation. Providers were well informed regarding disease interaction; were receptive to ICD, including implementation of better screening and referral processes; and favored improving interdisciplinary communication inclusive of access to integrated electronic health records. Perceived barriers and opportunities communicated by participants for advancing ICD were documented.

RSDL decontamination of human skin contaminated with the nerve agent VX

Dermal exposure to low volatile organophosphorus compounds (OPC) may lead to penetration through the skin and uptake in the blood circulation. Skin decontamination of toxic OPCs, such as pesticides and chemical warfare nerve agents, might therefore be crucial for mitigating the systemic toxicity following dermal exposure. Reactive skin decontamination lotion (RSDL) has been shown to reduce toxic effects in animals dermally exposed to the nerve agent VX. In the present study, an in vitro flow-through diffusion cell was utilized to evaluate the efficacy of RSDL for decontamination of VX exposed to human epidermis. In particular, the impact of timing in the initiation of decontamination and agent dilution in water was studied. The impact of the lipophilic properties of VX in the RSDL decontamination was additionally addressed by comparing chemical degradation in RSDL and decontamination efficacy between the VX and the hydrophilic OPC triethyl phosphonoacetate (TEPA). The epidermal membrane was exposed to 20, 75 or 90% OPC diluted in deionized water and the decontamination was initiated 5, 10, 30, 60 or 120min post-exposure. Early decontamination of VX with RSDL, initiated 5-10min after skin exposure, was very effective. Delayed decontamination initiated 30-60min post-exposure was less effective but still the amount of penetrated agent was significantly reduced, while further delayed start of decontamination to 120min resulted in very low efficacy. Comparing RSDL decontamination of VX with that of TEPA showed that the decontamination efficacy at high agent concentrations was higher for VX. The degradation mechanism of VX and TEPA during decontamination was dissected by ³¹P NMR spectroscopy of the OPCs following reactions with RSDL and its three nucleophile components. The degradation rate was clearly associated with the high pH of the specific solution investigated; i.e. increased pH resulted in a more rapid degradation. In addition, the solubility of the OPC in RSDL also influenced the degradation rate since the degradation of VX was significantly faster when the NMR analysis was performed in the organic solvent acetonitrile compared to water. In conclusion, we have applied the in vitro flow-through diffusion cell for evaluation of skin decontamination procedures of human epidermis exposed to OPCs. It was demonstrated that early decontamination is crucial for efficient mitigation of epidermal penetration of VX and that almost complete removal of the nerve agent from the skin surface is possible. Our data also indicate that the pH of RSDL together with the solubility of OPC in RSDL are of primary importance for the decontamination efficacy.

The Obesity Prevention Initiative: A Statewide Effort to Improve Child Health in Wisconsin

BACKGROUND/SIGNIFICANCE

Obesity rates have increased dramatically, especially among children and disadvantaged populations. Obesity is a complex issue, creating a compelling need for prevention efforts in communities to move from single isolated programs to comprehensive multisystem interventions. To address these issues, we have established a childhood Obesity Prevention Initiative (Initiative) for Wisconsin. This Initiative seeks to test community change frameworks that can support multisystem interventions and provide data for local action as a means for influencing policies, systems, and environments that support individuals’ healthy eating and physical activity.

APPROACHES/AIMS

The Initiative is comprised of three components: (1) infrastructure to support a statewide obesity prevention and health promotion network with state- and local-level public messaging and dissemination of evidence-based solutions (healthTIDE); (2) piloting a local, multisetting community-led intervention study in 2 Wisconsin counties; and (3) developing a geocoded statewide childhood obesity and fitness surveillance system.

RELEVANCE

This Initiative is using a new model that involves both coalition action and community organizing to align resources to achieve health improvement at local and state levels. We expect that it will help lead to the implementation of cohesive and sustainable policy, system, and environment health promotion and obesity prevention strategies in communities statewide, and it has the potential to help Wisconsin become a national model for multisetting community interventions to address obesity. Addressing individual-level health through population-level changes ultimately will result in reductions in the prevalence of childhood obesity, current and future health care costs, and chronic disease mortality.

Prevalence and Predictors of Unhealthy Weight Gain in Pregnancy

IMPORTANCE

Weight gain during pregnancy affects obesity risk in offspring.

OBJECTIVE

To assess weight gain among UW Health prenatal patients and to identify predictors of unhealthy gestational weight gain.

METHODS

Retrospective cohort study of women delivering at UW Health during 2007-2012. Data are from the UW eHealth Public Health Information Exchange (PHINEX) project. The proportion of women with excess and insufficient (ie, unhealthy) gestational weight gain was computed based on 2009 Institute of Medicine guidelines. Multivariable logistic regression was used to identify risk factors associated with excess and insufficient gestational weight gain.

RESULTS

Gestational weight gain of 7,385 women was analyzed. Fewer than 30% of prenatal patients gained weight in accordance with Institute of Medicine guidelines. Over 50% of women gained excess weight and 20% gained insufficient weight during pregnancy. Pre-pregnancy weight and smoking status predicted excess weight gain. Maternal age, race/ethnicity, smoking status, and having Medicaid insurance predicted insufficient weight gain.

CONCLUSIONS AND RELEVANCE

Unhealthy weight gain during pregnancy is the norm for Wisconsin women. Clinical and community interventions that promote healthy weight gain during pregnancy will not only improve the health of mothers, but also will reduce the risk of obesity in the next generation.

Development of an Obesity Prevention Dashboard for Wisconsin

IMPORTANCE

A comprehensive obesity surveillance system monitors obesity rates along with causes and related health policies, which are valuable for tracking and identifying problems needing intervention.

METHODS

A statewide obesity dashboard was created using the County Health Rankings model. Indicators were obtained through publicly available secondary data sources and used to rank Wisconsin amongst other states on obesity rates, health factors, and policies.

RESULTS

Wisconsin consistently ranks in the middle of states for a majority of indicators and has not implemented any of the evidence-based health policies.

CONCLUSIONS AND RELEVANCE

This state of obesity report shows Wisconsin has marked room for improvement regarding obesity prevention, especially with obesity-related health policies. Physicians and health care systems can play a pivotal role in making progress on obesity prevention.

Prevalence of Pre-pregnancy Obesity, 2011-2014

IMPORTANCE

Obesity before and during pregnancy increases risk among mothers for poor health outcomes, such as diabetes, high blood pressure, and cardiovascular disease.

OBJECTIVE

To describe trends in pre-pregnancy obesity rates among women in Wisconsin.

METHODS

Cross-sectional data from Wisconsin birth certificates were analyzed. Prevalence of pre-pregnancy obesity (defined as body mass index ≥ 30) among Wisconsin women who gave birth from 2011 through 2014 was compared across demographic and geographic dimensions.

RESULTS

Overall, 27.8% of Wisconsin women who gave birth during 2011-2014 were obese. Obesity rates were highest among 40- to 44-year-old women (31.8%), women with a high school/ GED diploma (32.8 %), American Indian/Alaska Native women (43.9%), and women with 5 or more pregnancies (35.4%). Obesity rates varied by county of residence (highest in Forest County, 45.2%) and city of residence (highest in the city of Racine, 34.8%).

CONCLUSIONS

There are significant socioeconomic, racial, and geographic disparities in pre-pregnancy obesity among women who give birth in Wisconsin.

Low adiponectin levels at baseline and decreasing adiponectin levels over 10 years of follow-up predict risk of the metabolic syndrome

AIM

Adiponectin is the most abundant adipokine and may play a key role in the interplay between obesity, inflammation, insulin resistance and the metabolic syndrome (MetS). Thus, this large population-based cohort investigated whether adiponectin at baseline and/or a decrease in adiponectin during follow-up is associated prospectively with the risk of incident MetS.

METHODS

Using a prospective study design, the development of MetS was examined in 1134 healthy participants from the community. Plasma adiponectin was measured at study entry and again after a median follow-up of 9.4 years (IQR: 9.2-9.7). During follow-up, 187 participants developed MetS, and 439 presented with at least two components of MetS.

RESULTS

During follow-up, adiponectin decreased in participants who developed MetS, whereas adiponectin was increased in those who did not develop MetS (P<0.001). Those with low adiponectin levels (quartile 1) at baseline had an increased risk of developing MetS (OR: 2.92, 2.08-6.97; P<0.001) compared with those with high levels (quartile 4). After adjusting for confounding variables, low adiponectin levels at baseline remained independently associated with MetS (OR: 2.24, 1.11-4.52; P=0.017). Similarly, participants with a decrease in adiponectin during follow-up also had an increased risk of MetS (OR: 2.96, 2.09-4.18; P<0.001). This association persisted after multivariable adjustments, including for baseline adiponectin (OR: 4.37, 2.77-6.97; P<0.001). Finally, adiponectin levels at follow-up were inversely associated with an increase in the number of components of MetS (P<0.001); geometric mean adiponectin levels were 9.5mg/L (95% CI: 9.0-10.0) for participants with no components vs 7.0mg/L (95% CI: 6.3-7.9) for those with four to five components.

CONCLUSIONS/INTERPRETATION

Low plasma adiponectin levels at baseline and decreasing adiponectin levels during follow-up are both associated with an increased risk of MetS.

Patient Exposure When Using 99Tcm-Dtpa for Evaluation of Cerebrospinal Fluid Shunt Patency

The absorbed dose from 99Tcm-DTPA was estimated from 12 investigations in 9 patients who were evaluated for the patency of ventriculo-peritoneal shunts. The distribution of 99Tcm-DTPA in the ventricles, urinary bladder and peritoneal cavity was determined in regions of interest from repeated static gamma camera images. The effective dose equivalent was calculated to be less than 0.10 mSv for an injected activity of 15 MBq.

Cadmium uptake in Elodea canadensis leaves and its interference with extra- and intra-cellular pH

This study investigated cadmium (Cd) uptake in Elodea canadensis shoots under different photosynthetic conditions, and its effects on internal (cytosolic) and external pH. The plants were grown under photosynthetic (light) or non-photosynthetic (dark or in the presence of a photosynthetic inhibitor) conditions in the presence or absence of CdCl2 (0.5 μm) in a medium with a starting pH of 5.0. The pH-sensitive dye BCECF-AM was used to monitor cytosolic pH changes in the leaves. Cadmium uptake in protoplasts and leaves was detected with a Cd-specific fluorescent dye, Leadmium Green AM, and with atomic absorption spectrophotometry. During cultivation for 3 days without Cd, shoots of E. canadensis increased the pH of the surrounding water, irrespective of the photosynthetic conditions. This medium alkalisation was higher in the presence of CdCl2 . Moreover, the presence of Cd also increased the cation exchange capacity of the shoots. The total Cd uptake by E. canadensis shoots was independent of photosynthetic conditions. Protoplasts from plants exposed to 0.5 μm CdCl2 for 3 days did not exhibit significant change in cytosolic [Cd(2+)] or pH. However, exposure to CdCl2 for 7 days resulted in increased cytosolic [Cd(2+) ] as well as pH. The results suggest that E. canadensis subjected to a low CdCl2 concentration initially sequesters Cd into the apoplasm, but under prolonged exposure, Cd is transported into the cytosol and subsequently alters cytosolic pH. In contrast, addition of 10-50 μm CdCl2 directly to protoplasts resulted in immediate uptake of Cd into the cytosol.

Spontaneous conversion of first onset atrial fibrillation

BACKGROUND/AIM

We studied all patients admitted to hospital with first onset atrial fibrillation (AF) to determine the probability of spontaneous conversion to sinus rhythm and to identify factors predictive of such a conversion.

METHODS

We retrospectively reviewed charts of 438 consecutive patients admitted to hospital with first onset AF from 1 January 2006 to 31 December 2009. The patients were divided into two groups, recent onset AF defined as AF < 48 h or longer lasting AF, defined as AF > 48 h.

RESULTS

Spontaneous conversion occurred in 54% (n = 203; 95% confidence interval: 49-59%). In the group with first onset AF < 48 h, spontaneous conversion occurred in 77%, compared with 36% in the group with first onset AF > 48 h. Logistic regression analysis identified duration of AF as a highly significant predictor of spontaneous conversion to sinus rhythm (odds ratio 5.9; 95% confidence interval: 4.0-8.6, P < 0.001).

CONCLUSIONS

Spontaneous conversion occurred in 54%, increasing to 77% when AF had persisted less than 48 h.

Non-invasive diagnostics of the maxillary and frontal sinuses based on diode laser gas spectroscopy

PROBLEM

Suspected, but objectively absent, rhinosinusitis constitutes a major cause of visits to the doctor, high health care costs, and the over-prescription of antibiotics, contributing to the serious problem of resistant bacteria. This situation is largely due to a lack of reliable and widely applicable diagnostic methods.

METHOD

A novel method for the diagnosis of rhinosinusitis based on non-intrusive diode laser gas spectroscopy is presented. The technique is based on light absorption by free gas (oxygen and water vapour) inside the sinuses, and has the potential to be a complementary diagnostic tool in primary health care. The method was evaluated on 40 patients with suspected sinus problems, referred to the diagnostic radiology clinic for low-dose computed tomography (CT), which was used as the reference technique.

MAIN RESULTS

The data obtained with the new laser-based method correlated well with the grading of opacification and ventilation using CT. The sensitivity and specificity were estimated to be 93% and 61%, respectively, for the maxillary sinuses, and 94% and 86%, respectively, for the frontal sinuses. Good reproducibility was shown.

PRINCIPAL CONCLUSION

The laser-based technique presents real-time clinical data that correlate well to CT findings, while being non-intrusive and avoiding the use of ionizing radiation.

Vestibular PREHAB and gentamicin before schwannoma surgery may improve long-term postural function

BACKGROUND

Unilateral vestibular deafferentation (uVD), as performed in vestibular schwannoma surgery, results in a chronic vestibular deficit, though most of the insufficiency can be compensated by other sensory input. By vestibular training (prehabituation) performed before surgery, motor adaptation processes can be instigated before the actual lesion. The adaptation processes of the altered sensory input could be affected if the vestibular ablation and surgery were separated in time, by pretreating patients who have remaining vestibular function with gentamicin.

OBJECTIVE

To determine whether presurgical deafferentation would affect postsurgery postural control also in a long-term perspective (6 months).

METHOD

41 patients subjected to trans-labyrinthine schwannoma surgery were divided into four groups depending on the vestibular activity before surgery (with no clinical significant remaining function n = 17; with remaining function n = 8), whether signs of central lesions were present (n = 10), and if patients with remaining vestibular activity were treated with gentamicin with the aim to produce uVD before surgery (n = 6). The vibratory posturography recordings before surgery and at the follow-up 6 months after surgery were compared.

RESULTS

The subjects pretreated with gentamicin had significantly less postural sway at the follow-up, both compared with the preoperative recordings and compared with the other groups.

CONCLUSION

The results indicate that by both careful sensory training and separating the surgical trauma and the effects of uVD in time, adaptive processes can develop more efficiently to resolve sensory conflicts, resulting in a reduction of symptoms not only directly after surgery but also perhaps up to 6 months afterwards.

Improvement of absorption enhancing effects of n-dodecyl-β-d-maltopyranoside by its colon-specific delivery using chitosan capsules

In general, absorption enhancing effects of various absorption enhancers were greater in the large intestine than those in the small intestinal regions. Therefore, the effectiveness of absorption enhancers is expected to be remarkably observed, if these enhancers can be delivered to the large intestine with some poorly absorbable drugs after oral administration. In this study, therefore, we examined whether chitosan capsules were effective for the colon-specific delivery of a certain absorption enhancer and can improve the absorption enhancing action of the absorption enhancer after oral administration. 5(6)-Carboxyfluorescein (CF) was used as a model drug to investigate the site-dependent effectiveness of various absorption enhancers by an in situ closed loop method. Sodium glycocholate (NaGC), n-dodecyl-beta-d-maltopyranoside (LM), sodium salicylate (NaSal) and sodium caprate (NaCap) were used as models of absorption enhancers in this study. Overall, the absorption enhancing effects of these enhancers for intestinal absorption of CF were greater in the colon than those in the jejunum and the ileum. Especially, among these enhancers tested in this study, LM showed much greater absorption enhancing effect in the colon than in the jejunum and the ileum. Therefore, LM was selected as a model absorption enhancer to examine the effect of chitosan capsules on the absorption enhancing effect of LM. When CF and LM were orally administered to rats using chitosan capsules, the plasma concentration of CF was much higher than those in other dosage forms including solution and gelatin capsules. Therefore, chitosan capsules may be useful carriers for colon-specific delivery of LM, thereby increasing its absorption enhancing effect from the intestinal membranes.

Radiotherapy of childhood haemangiomas: from active treatment to radiation risk estimates

Childhood skin haemangiomas have been subjected to many different kinds of active treatment. From the beginning of the twentieth century and up to 1960-1970, radiotherapy maintained a dominating place in this treatment, although during the latter part of this period its role was more and more questioned. Starting in 1958, I felt that, based on the scientific literature and on my own observations at Malmö University Hospital, active therapy including radiotherapy should be abandoned since it had turned out to be unnecessary and, furthermore, could be harmful. This viewpoint resulted from an increased knowledge of the natural history of the disease. I then got the possibility to establish a follow-up study cohort at Sahlgrenska University Hospital in Göteborg with the aim of gaining information on early and late radiation effects following childhood radiotherapy. Later, the study cohort was enlarged by pooling with similar cohorts originating from Stockholm and Paris. A summary of the results of the epidemiological studies is also presented here. This historical overview reflects half a century of radiation therapy and radiation protection philosophy. It contains a basic message pointing to the value of proper and reliable collection of medical data and to the importance of local, regional and national registers, to preserve the information.

Paranasal sinus ventilation in healthy subjects and in patients with sinus disease evaluated with the 133-xenon washout technique

Ventilation of the paranasal sinuses is of great importance in sinus pathophysiology. Therefore, methods of measuring sinus ventilation are important for the evaluation of patients with sinus disease. In the present study, a 133-xenon washout technique was used to evaluate the ventilation of the paranasal sinuses in 34 healthy subjects and in 13 subjects with sinus disease (5 patients with nasal polyposis and 8 patients with chronic sinusitis). For this purpose, a 133-xenon-air mixture was insufflated in each nostril and the washout of the radioactive gas from the paranasal sinuses was monitored with a dynamic single-photon-emission computed tomography camera. The half-time (+/-SD) was found to be 18 +/- 18 minutes for the maxillary sinus, 10 +/- 8 minutes for the frontal sinus, and 18 +/- 23 minutes for the posterior ethmoid and sphenoid sinuses in the healthy subjects. Repeated measurements in 18 of the healthy subjects indicated that the method had acceptable reproducibility according to a Bland-Altman plot. The 133-xenon washout was not influenced by insufflation pressure, nasal patency, or body position. The subjects with sinus disease exhibited half-times of 77 +/- 101 minutes for the maxillary sinus, 91 +/- 124 minutes for the frontal sinus, and 60 +/- 60 minutes for the posterior ethmoid and sphenoid sinuses. For patients with nasal polyposis, the half-time was significantly longer than that in healthy subjects, while patients with chronic sinusitis did not differ from healthy subjects in this respect.

Nasal nitric oxide

Nitric oxide (NO) has witnessed an explosion of interest of scientists all over the world during the last decade. This small gaseous molecule is produced in many systems such as the nervous system, cardiovascular system, the upper and lower airways. In all of these it contributes to a number of (patho)physiological processes. Concerning the airways, NO concentrations in the upper respiratory tract are much higher (i.e. ranging from 200 to 2000 parts per billion (ppb)) than NO levels in the lower respiratory tract (i.e. ranging from 4 to 160 ppb). NO is most frequently measured using a chemiluminescence method, based on a reaction of NO with O3 resulting in the emission of light. In the airways NO exerts many functions in host defense, ciliary activity, inflammation and it is also an aerocrine messenger between the upper and lower airways. Nasal NO concentrations are influenced by age, physical exercise, smoking and certain drugs. Nasal NO is conveniently measured in all ages and can be used for screening of disease or monitoring the effects of treatment. Pathological conditions, as in allergic rhinitis, sinusitis, nasal polyps, cystic fibrosis and primary ciliary dyskinesia, result in altered nasal NO concentrations. The clinical relevance for measurement of nasal NO in different conditions, however, remains to be established.

Factors influencing 133-xenon washout in a nose-sinus model

The 133-xenon washout technique is a non-invasive method for the evaluation of ventilation of the paranasal sinuses. The half-time of 133-xenon washout (T(1/2)) is considered to reflect sinus ostial function and sinus ventilation. However, it is not known how morphological and physiological factors affect the washout from the paranasal sinuses. The aim of the present study was to evaluate how sinus volume, ostial diameter and nasal ventilation influence 133-xenon washout in a nose-sinus model. This is important for the interpretation of measurements of 133-xenon washout from paranasal sinuses in healthy subjects and in subjects with sinus disease. The 133-xenon washout was measured with a scintillation camera. The statistical analysis of the results showed that the logarithm (to the base 10) of the half-time of 133-xenon washout is linearly related to the ostial diameter, the sinus volume and the nasal ventilation in the model. In a multiple linear regression model, the most important factor contributing to 133-xenon washout was found to be the ostial diameter, which explained 76% of the variation in log T(1/2). In the same statistical model the sinus volume explained 7.5% and the ventilation 5.3% of the variation in log T(1/2). Calculations of the functional ostial diameter in healthy subjects were made, based on the results of the model study. The mean functional ostial diameter was found to be 3.5 mm (range 0.5-7.5 mm). The results obtained with the present model experiments may be of importance for the correct interpretation of the results of measurements of 133-xenon washout in healthy subjects and patients.

Ciliostimulatory effects mediated by nitric oxide

Ciliostimulation induced by various transmitters has been suggested to be mediated by the release of nitric oxide (NO). Freshly obtained adenoid tissue explants were pre-treated with the nitric oxide synthase (NOS) inhibitor N(G)-nitro L-arginine (L-NNA), to determine whether the ciliostimulators terbutaline, methacholine, substance P, and endothelin-1 require the release of NO to increase ciliary beat frequency (CBF) in vitro. The L-NNA pre-treatment affected the change in CBF induced by each of the ciliostimulators tested. To determine whether cyclic nucleotides also stimulate CBF by inducing the release of NO, an extra series of experiments were performed with dibutyryl cAMP and dibutyryl cGMP, and L-NNA pre-treatment. In contrast to the experiments with the various ciliostimulators, both dibutyryl cAMP and dibutyryl cGMP exerted ciliostimulatory effects that could not be inhibited by L-NNA. The present findings suggest that NO acts as an intermediate messenger in the ciliated epithelium in response to various transmitters and mediators. On the other hand, pre-treatment with the NOS inhibitor L-NNA did not affect ciliary response to the second messengers cAMP and cGMP, thus suggesting that NO dependent mechanisms do not constitute the sole pathway for the stimulation of ciliary function.

Effects on the ciliated epithelium of protein D-producing and -nonproducing nontypeable Haemophilus influenzae in nasopharyngeal tissue cultures

A pair of isogenic, nontypeable Haemophilus influenzae strains, one expressing protein D and the other protein D-negative, was compared in their ability to cause damage in a human nasopharyngeal tissue culture model. Damage was assessed by measuring the ciliary beat frequency (CBF) of tissue specimens at 12 h intervals. Cultures inoculated with H. influenzae manifested a decrease in CBF beginning after 12 h, with a maximum decrease after 36 h. The impairment of ciliary function by the protein D-expressing strain was significantly greater than that caused by the protein D-negative mutant (P<.01). Tissue specimens examined by scanning and transmission electron microscopy after 24 h appeared normal. After 48 h of incubation, the protein D-expressing strain caused a significant loss of cilia. These findings suggest that protein D is involved in the pathogenesis of upper respiratory tract infections due to nontypeable H. influenzae, probably by enhancing functional and morphological damage to cilia.

Hearing as substitution for sensation: a new principle for artificial sensibility

We describe a new principle for artificial sensibility of the hand based on sense substitution, using hearing as substitution for loss of sensation. The experiments were performed on 3 patients who had recently undergone isolated median nerve repair, 1 patient with replantation of an amputated forearm, 1 patient using a myoelectric prosthesis, and 4 patients using cosmetic prostheses. Small condenser microphones were mounted dorsally on the distal phalanges of multiple fingers of the nonsensate hands or prostheses. The friction sound, reflecting the vibrotactile stimuli generated by the moving touch of the objects, was picked up by the microphones and processed in a stereo amplifier that separated signals from individual fingers into different channels. The signals were transmitted to earphones, making possible a spatial resolution that enabled identification of each finger by the generated acoustic stimuli. Since the friction sound is characteristic of specific surfaces and textures, the corresponding acoustic stimuli made possible identification of different textures, such as glass, metal, wood, and paper, without using vision. We conclude that sense substitution using specifically processed acoustic stimuli as a substitute for sensation may represent a useful principle for generation of artificial sensibility in prostheses or hands lacking sensibility due to lesions in the peripheral or central nervous system or because of neurologic disease.

Artificial sensibility based on the use of piezoresistive sensors. Preliminary observations

Piezoresistive sensors, applied to the fingertips of non-sensate fingers, were used for the detection of touch and pressure in four patients with recent median nerve repairs, and in one patient using a myoelectric prosthesis. The signals from the sensors, produced by the tactile stimuli, were processed and transposed as electrical stimuli to sensate skin of the ipsi- or contralateral arm by the use of skin electrodes. With this setup the test subjects could rapidly learn to differentiate between tactile stimuli applied to different fingers, thereby regaining spatial resolution in the hand. All five patients rapidly improved their ability to regulate the power of pinch grip without the help of vision. The patient with a hand prosthesis rapidly learned to discriminate between four different levels of pressure, applied to the thumb by four different Semmes--Weinstein monofilaments (75, 125, 280 and 450 g). These results indicate that the system is of potential value for patients lacking sensibility or using prostheses.

Nitric oxide is a regulator of mucociliary activity in the upper respiratory tract

The in vitro effects of the nitric oxide (NO) substrate L-arginine on ciliary beat frequency and the in vivo effects of the NO donor sodium nitroprusside (SNP) on mucociliary activity were investigated in the rabbit maxillary sinus mucosa with photoelectric techniques. L-Arginine increased ciliary beat frequency in vitro with a maximum response of 27.1% +/- 6.4% at 10(-3) mol/L, and this effect was reversibly blocked by pretreatment with the NO synthase (NOS) inhibitor N(G)-nitro-L-arginine, whereas D-arginine had no such effect. SNP increased mucociliary activity in vivo, the peak response of 36.8% +/- 4.2% being obtained at the dose of 30.0 microg/kg. No tachyphylaxis was observed after repeat challenge with SNP. The increase in mucociliary activity caused by SNP was largely unaffected by pretreatment with the calcium channel blocker nifedipine, the cyclooxygenase inhibitor diclofenac, and the cholinergic antagonist atropine. The nonselective beta-blocker propranolol delayed the peak response of SNP to 7 to 8 minutes after challenge, compared with 1 to 2 minutes after challenge in animals without pretreatment. The results show the NO substrate L-arginine and the NO donor SNP to have ciliostimulatory effects in vitro and in vivo, respectively. The occurrence of NOS production in the sphenopalatine ganglion and sinus mucosa of the rabbit was studied by immunohistochemistry for NOS activity or nicotinamide adenine dinucleotide phosphate-diaphorase histochemistry. The latter is an indirect sign of neuronal NOS activity. Numerous NOS-containing cell bodies were seen in the sphenopalatine ganglion; in the sinus mucosa a moderate supply of thin NOS-immunoreactive nerve fibers was seen. Taken together, the morphologic findings and the functional results indicate NO to be a regulator of mucociliary activity in upper airways.

Changes in mucociliary activity may be used to investigate the airway-irritating potency of volatile anaesthetics

We have examined the short-term effects of three volatile anaesthetics, halothane, isoflurane and desflurane, on mucociliary activity in the rabbit maxillary sinus in vivo. Mucociliary activity was recorded photoelectrically and the signal processed by fast Fourier transformation. Administration of 1.0 MAC of halothane, isoflurane or desflurane caused a temporary increase in mucociliary activity, with mean peak responses of 47.8 (SEM 13.0)%, 44.0 (9.6)% and 45.1 (23.7)% (n = 6), respectively. The response to all three compounds was biphasic; an initial peak was observed within 2 min and a second peak at 3-8 min. The second response was not significant for halothane. In contrast, desflurane produced a significant second peak while the first was small and failed to reach significance. Halothane displayed an initial peak within 2 min which was blocked by atropine but not by the neurokinin 1 (NK1) receptor antagonist CP-99. The second peak at 3-5 min was less pronounced for halothane than for isoflurane or desflurane. The second peak was not affected by atropine pretreatment, but was blocked by pretreatment with CP-99. A combination of atropine and CP-99 pretreatment abolished the mucociliary response to halothane. Atropine pretreatment did not affect, whereas CP-99 significantly reduced, the response to desflurane. We conclude that the NK1-mediated response was most pronounced for desflurane which is considered the most airway irritating compound of the three. It is likely that the size of the NK1-mediated response reflects the airway-irritating properties of the volatile anaesthetic used.