Nocturnal hypoxia in motor neuron disease is not predicted by standard respiratory function tests

Background: With increasing awareness of motor neuron disease (MND) in Australia, the approach to respiratory management of patients with this disease will more commonly face the respiratory physician. Aim: The aim of this study was to determine if standard respiratory function tests could determine the presence of nocturnal hypoxia (NH) in patients with MND. Methods: Respiratory function tests were used to examine daytime respiratory function, and sleep studies were used to detect NH in 16 consecutive patients with MND and in 9 healthy control subjects. Demographic data, clinical parameters, respiratory function tests and sleep studies were obtained. Statistical analyses were carried out using t-tests and anova, where appropriate. Results: NH was detected in 50% of patients with MND, with no hypoxic events detected in the control group. Standard respiratory function tests were not able to predict the presence of NH. Conclusion: There was no correlation between respiratory function tests and NH. This study emphasizes the inability of standard respiratory function tests to predict NH that may arise early in the course of MND.4 page(s

Sexually-Transmitted Disease in a Sub-Tropical Eucalypt Beetle: Infection of the Fittest?

The ecology of sexually-transmitted diseases (STDs) is topical in scientific research, and their demography and epidemiology differ from those of classical pathogens and parasites. Transmission of STDs is generally density-independent, occurs via the "fittest" individuals in a population (or, at least, those that achieve the most matings), and reflects differential mating success. STDs can therefore have a major influence on the evolution of host mating systems. We studied the epidemiology of a recently described STD of a chrysomelid beetle in applied and theoretical contexts, exploring the virulence, intensity and prevalence of infection, and using our results to test ecological predictions. Chrysophtharta cloelia is infected with a sexually-transmitted mite (the STD), Parobia captivus. Infection rate over three beetle generations (7 months) was determined and the STD’s effects on fertility, fecundity, longevity, mating success and overwintering survival was measured. Throughout the season around 40% of beetles were infected, with approximately one quarter of such hosts carrying infective life stages of the STD at any one time. Infection by P. captivus significantly decreased overwintering survival, but did not impact on other fitness parameters measured, including mate acceptance. However, more female beetles were infected than male beetles, while within both sexes larger beetles were more likely to be infected. Our results concur with theoretical predictions that STDs may be selected for low virulence and low detectability, while the observation of female bias in infection supports hypotheses regarding variable mating success and mating skews, which we discuss

Containership routing problem with stochastic travel times, simultaneous deliveries and pick-ups and time deadlines: Τhe case of the Aegean Sea

172 σ.Η ισχυρή επίδραση των καιρικών συνθηκών στη λειτουργία των εμπορικών πλοίων επιδρά σημαντικά στο συνολικό χρόνο εν πλω αλλά και στο ολικό κόστος της μεταφορικής διαδικασίας. Η παρούσα διπλωματική εργασία εστιάζει στο αντικείμενο της δρομολόγησης πλοίων μεταφοράς εμπορευματοκιβωτίων, με στοχαστική όμως θεώρηση των χρόνων διαδρομής, ένεκα της παραπάνω επίδρασης. Αναζητείται, δηλαδή, ο βέλτιστος καθορισμός διαδρομών για έναν ομοιογενή στόλο πλοίων που θα παραλαμβάνει, μεταφέρει και επιδίδει εμπορευματοκιβώτια μεταξύ ενός κεντρικού λιμένα και ενός συνόλου λιμένων που τροφοδοτούνται από αυτόν. Στο πλαίσιο αυτό, μορφώνεται ένα πρόβλημα δρομολόγησης με στοχαστικούς χρόνους διαδρομής, ταυτόχρονη παραλαβή και επίδοση εμπορευμάτων και χρονικούς περιορισμούς, για την επίλυση του οποίου αναπτύσσεται μεθευρετικός αλγόριθμος. Παράλληλα, οργανώνεται η διαδικασία για την εκτίμηση της πιθανοτικής κατανομής των χρόνων διαδρομής του κάθε πλοίου. Το αναπτυσσόμενο πρότυπο εφαρμόζεται σε ένα δίκτυο νησιωτικών λιμένων του Αιγαίου πελάγους. Τα αποτελέσματα από την εφαρμογή καταδεικνύουν ότι ένας μικρού μεγέθους στόλος επαρκεί για την εξυπηρέτηση των αναγκών του δικτύου με μικρές σχετικά καθυστερήσεις, ενώ η διερεύνηση σεναρίων, όπου μεταβάλλονται βασικές παράμετροι του προβλήματος, οδηγούν σε ενθαρρυντικά συμπεράσματα σχετικά με την αποδοτικότητα και την ευρωστία του αλγορίθμου.The strong effect of weather conditions on the operation of commercial vessels has a major influence on the total time at sea and on the total cost of the transport process. This thesis focuses on containership routing, with stochastic consideration of travel times due to the above effect. Ιn this context, aims to determine optimal routes for a homogeneous fleet performing pick-ups, transport and deliveries of containers between a hub and several spoke ports, fed by the hub. The problem is originally formulated as a vehicle routing problem with stochastic travel times with simultaneous pick-ups and deliveries and time constraints and solved using a metaheuristics algorithm. The developed model is implemented to a network of island ports of the Aegean Sea. Results on the application of algorithm reveal that a small fleet is sufficient enough to serve network’s islands, under the influence of minor delays. The investigation of alternative scenarios, characterized by changes in the problem’s parameters, leads to encouraging conclusions in respect of efficiency and robustness of the algorithm.Γρηγόριος Χ. Φούντα

Evidence for opioid modulation and generation of prostaglandins in sulphur dioxide (SO)2-induced bronchoconstriction.

BACKGROUND: Inhalation of sulphur dioxide (SO2) provokes bronchoconstriction in asthmatic subjects. Cholinergic mechanisms contribute, but other mechanisms remain undefined. The effect of morphine, an opioid agonist, on the cholinergic component of SO2-induced bronchoconstriction was investigated, and the effect of indomethacin, a cyclooxygenase inhibitor, on SO2-induced bronchoconstriction and tachyphylaxis was studied. METHODS: In the first study 16 asthmatic subjects inhaled either ipratropium bromide or placebo 60 minutes before an SO2 challenge on days 1 and 2. On day 3 an SO2 challenge was performed immediately after intravenous morphine. In the second study 15 asthmatic subjects took either placebo or indomethacin for three days before each study day when two SO2 challenges were performed 30 minutes apart. The response was measured as the cumulative dose causing a 35% fall in specific airways conductance (sGaw; PDsGaw35). RESULTS: Ipratropium bromide significantly inhibited SO2 responsiveness, reducing PDsGaw35 by 0.89 (95% CI 0.46 to 1.31) doubling doses. This effect persisted after correction for bronchodilatation induced by ipratropium bromide. The effect of ipratropium bromide and morphine on SO2 responsiveness also correlated (r2 = 0.71). In the second study SO2 tachyphylaxis developed with PDsGaw35 on repeated testing, being reduced by 0.62 (95% CI 0.17 to 1.07) doubling doses. Indomethacin attenuated baseline SO2 responsiveness, increasing PDsGaw35 by 0.5 (95% CI 0.06 to 0.93) doubling doses. CONCLUSIONS: These results suggest that opioids modulate the cholinergic component of SO2 responsiveness and that cyclooxygenase products contribute to the immediate response to SO2

The safety and efficacy of inhaled dry powder mannitol as a bronchial provocation test for airway hyperresponsiveness: a phase 3 comparison study with hypertonic (4.5%) saline

BACKGROUND: Inhaled mannitol is a new bronchial provocation test (BPT) developed to improve portability and standardisation of osmotic challenge testing. Osmotic challenge tests have an advantage over the traditional methods of measuring airway hyperresponsiveness using methacholine as they demonstrate higher specificity to identify asthma and thus the need for treatment with inhaled corticosteroids (ICS). The safety and the efficacy of mannitol (M) as a BPT to measure airway hyperresponsiveness were compared to hypertonic (4.5%) saline (HS) in people both with and without signs and symptoms of asthma. METHODS: A phase III, multi-centre, open label, operator-blinded, crossover design, randomised trial, with follow-up. Asthmatics and non-asthmatics (6-83 yr) were recruited and 592 subjects completed the study. Mannitol was delivered using a low resistance dry powder inhaler and HS was delivered using an ultrasonic nebuliser. The FEV1 was measured 60 seconds after each dose of mannitol (5,10,20,40,80,160,160,160 mg) and after each exposure to HS (0.5,1.0,2.0,4.0,8.0 minutes). A 15% fall in FEV1 defined a positive test. Adverse events were monitored and diaries kept for 7 days following the tests. RESULTS: Mean pre-test FEV1 (mean +/- SD) was 95.5 +/- 14% predicted. 296 were positive to mannitol (M+) and 322 positive to HS (HS+). A post study physician conducted clinical assessment identified 82.3% asthmatic (44% classified mild) and 17.7% non-asthmatic. Of those M+, 70.1% were taking ICS and of those mannitol negative (M-), 81.1 % were taking ICS. The % fall in FEV1 for mannitol in asthmatics was 21.0% +/- 5.7 and for the non-asthmatics, 5.5% +/- 4.8. The median PD15 M was 148 mg and PD15 HS 6.2 ml. The sensitivity of M to identify HS+ was 80.7% and the specificity 86.7%. The sensitivity of M compared with the clinical assessment was 59.8% and specificity 95.2% and increased to 88.7% and 95.0% respectively when the M- subjects taking ICS were excluded. Cough was common during testing. There were no serious adverse events. The diarised events were similar for mannitol and HS, the most common being headache (17.2%M, 19%HS), pharyngolaryngeal pain (5.1%M, 3%HS), nausea (4.3%M, 3%HS), and cough (2.2%M, 2.4%HS). CONCLUSION: The efficacy and safety of mannitol was demonstrated in non-asthmatic and clinically diagnosed asthmatic adults and children