Mast cell involvement in the rat paw oedema response to 1,8-cineole, the main constituent of eucalyptus and rosemary oils

The present studies tested the ability of 1,8-cineole to produce inflammatory oedema in the hind paw of the rat and verified the possible involvement of mast cells in the response. Subplantar injection of 1,8-cineole (10, 15 and 20 microl/paw) induced a dose-dependent paw oedema which was apparent within 30 min. At higher doses the oedema effect was persistent, peaked at 2 h, and then decreased gradually but was still pronounced at 24 h post injection. In contrast, the oedema produced by mast cell degranulator compound 48/80 (10 microg/paw) had a rapid onset with a peak effect at the first hour, followed by a gradual decrease thereafter and at 24 h post injection it was almost absent. The oedema response to 20 microl 1,8-cineole was significantly inhibited throughout its time-course in rats pretreated with antihistaminic and antiserotonergic drugs such as diphenhydramine, methysergide and cyproheptadine or with ketotifen, a mast cell stabilizer. A more effective blockade of the oedema response was, however, observed in rats depleted of mast cell granules by systemic treatment with compound 48/80. Furthermore, 1,8-cineole was able to cause rat peritoneal mast cell degranulation (94%) in vitro, in a concentration as low as 0.3 microl/ml, which was almost comparable to that produced by 0.1 microg/ml of compound 48/80. The data provide evidence of a key role for the mast cell in 1,8-cineole-induced hind paw oedema in the rat.     

Influence of fluoride-containing solutions on the translucency of flowable composite resins

The aim of this study was to evaluate the influence of fluoride-containing solutions on the translucency of flowable composite resins, with respect the immersion time. Flow-It! (FI) and Natural Flow (NF) composite resins and three commercial brands of fluoride-containing solutions (Fluordent, Fluorgard and Oral B) were used. Specimens were prepared and stored in the solutions at 37°C, until the measurements were made after the following treatments: T1 - after 1 hour in relative humidity; T2 - after 1 h in solution; T3 - 24 h; T4 - 48 h; T5 - after a week; from T9, the measurements were accomplished weekly, up to 30-day immersion. To obtain translucency values an electrophoresis equipment was employed. Data were submitted to ANOVA and Tukey tests. The results disclosed that NF showed highest values of translucency and was statistically different from FI (p< 0.001). As regards the solutions, Fluordent and Oral B presented similar values and were statistically superior to Fluorgard (p< 0.05). Concerning the immersion time, similar results were observed for the different evaluation periods. It may be concluded that the fluoride-containing solutions affected the translucency of the composite resins, independently of the materials used. Among the tested resins, NF presented the best performance.     

Dithioester functionalization of poly(cyclohexene oxide) and its application to obtain block copolymers

A new method of introducing dithioester groups into the polymer chain of poly(cyclohexene oxide) is reported. It includes the use of diaryliodonium salt and an aromatic dithioacid as a redox couple to initiate the cationic polymerization of cyclohexene oxide. It was found that the dithioacid by itself cannot start the polymerization of cationic polymerizable monomers; however, in combination with a diaryliodonium salt, an exothermic reaction was produced, yielding a thiocarbonylthio‐functionalized polyether. Thermal profiles of the redox polymerizations were determined by means of optical pyrometry. A preliminary study showed that when the poly(cyclohexene oxide) functionalized with dithioester groups was introduced into the radical polymerization of styrene, the polystyryl growing radicals reacted with the dithioester‐functionalized polyether to form a block polymer. The amount of polyether actually incorporated into the block copolymer was calculated to be 70% of the initial amount of poly(cyclohexene oxide)/dithiobenzoic acid charged into the reactor. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Ruthenium red and capsazepine antinociceptive effect in formalin and capsaicin models of pain in mice

This study investigates the antinociception caused by intradermal (i.d) or intracerebroventricular (i.c.v.) injection of the capsaicin receptor antagonist capsazepine (CPZ), and ruthenium red (RR) (a cation-selective antagonist coupled to vanilloid receptor of capsaicin), on the chemical nociception caused by i.d. injection of formalin (FM) and capsaicin (CAP) into the mouse paw. The i.d. injection of either CPZ or RR in association with FM or CAP, inhibited the early phase, and to a lesser extent the late phase, of the FM, as well as CAP-induced nociception. Given i.c.v., both CPZ and RR caused discrete antinociception in the FM (both phases), while producing graded inhibition of CAP. The actions of CPZ and RR were insensitive to i.p. injection of naloxone (5 mg/kg). These results indicate that i.d. injection of CPZ and RR produce marked antinociception in chemical models of neurogenic pain induced by CAP and FM in mice. However, administered by supraspinal site, both CPZ and RR were inactive in inhibiting FM, but prevented, in a graded manner, CAP-induced algesic response, suggesting the participation of distinct mechanisms in the nociception induced by FM and CAP. Thus, vanilloid selective antagonists seem to be useful tools for investigating the nociception elicited by CAP and FM.     

Epidural injection of ketamine for perineal analgesia in the horse

Work-related respiratory symptoms, acute lung function changes and personal endotoxin exposure were studied in 61 workers from a potato processing plant. According to their job title mean endotoxin exposure level, workers were divided into low (AM = 21 EU/m3) and high (AM = 56 EU/m3) exposure categories. Shortness of breath and chest tightness during work were reported by 18% and 16% of the workers, respectively, mainly in the low endotoxin exposure category. A total of 148 across-shift lung function changes were measured during three consecutive afternoon shifts. The mean FEV1 and MMEF showed a decrease over the work shift, being largest on the first working day after a 3-day absence from work. Workers exposed to high endotoxin levels showed a larger across-shift decrease in lung function than workers exposed to low endotoxin exposures, the effect being most pronounced on the first day after a 3-day absence from work. At the start of the second work shift, FVC, FEV1 and MMEF were lower than at the start of the first work shift. This difference was larger for high exposed workers. High exposed workers with work-related respiratory symptoms showed an 8-10% across-shift change in FVC, FEV1 and MMEF We conclude that significant across-shift decreases in lung function of potato processing workers is related to endotoxin exposure levels above 53 EU/m3 over 8 hr.     

Sleep-related O2 desaturation and daytime pulmonary haemodynamics in COPD patients with mild hypoxaemia

It has been hypothesized but not firmly established that sleep-related hypoxaemia could favour the development of pulmonary hypertension in chronic obstructive pulmonary disease (COPD) patients without marked daytime hypoxaemia. We have investigated the relationships between pulmonary function data, sleep-related desaturation and daytime pulmonary haemodynamics in a group of 94 COPD patients not qualifying for conventional O2 therapy (daytime arterial oxygen tension (Pa,O2) in the range 7.4-9.2 kPa (56-69 mmHg)). Nocturnal desaturation was defined by spending > or = 30% of the recording time with a transcutaneous O2 saturation < 90%. An obstructive sleep apnoea syndrome was excluded by polysomnography. Sixty six patients were desaturators (Group 1) and 28 were nondesaturators (Group 2). There was no significant difference between Groups 1 and 2 with regard to pulmonary volumes and Pa,O2 (8.4+/-0.6 vs 8.4+/-0.4 kPa (63+/-4 vs 63+/-3 mmHg)) but arterial carbon dioxide tension (Pa,CO2) was higher in Group 1 (6.0+/-0.7 vs 53+/-0.5 kPa (45+/-5 vs 40+/-4 mmHg); p<0.0001). Mean pulmonary artery pressure (Ppa) was very similar in the two groups (2.6+/-0.7 vs 2.5+/-0.6 kPa (19+/-5 vs 19+/-4 mmHg)). No individual variable or combination of variables could predict the presence of pulmonary hypertension. It is concluded that in these patients with chronic obstructive pulmonary disease with modest daytime hypoxaemia, functional and gasometric variables (with the noticeable exception of arterial carbon dioxide tension) cannot predict the presence of nocturnal desaturation; and that mean pulmonary artery pressure is not correlated with the degree and duration of nocturnal hypoxaemia. These results do not support the hypothesis that sleep-related hypoxaemia favours the development of pulmonary hypertension.     

Cloning and sequencing of a full-length sea bream (Sparus aurata) beta-actin cDNA

The pathogenesis of human African trypanosomiasis (HAT) has been the object of considerable research interest but has remained incompletely understood. The importance of cytokines in the pathophysiology of this protozoan infection is now widely recognized, but the full spectrum of cytokines involved has yet to be determined. In the present investigation we compared the plasma concentrations of TNF-alpha and IL-10 in normal African controls and patients suffering from advanced meningocephalic (late-stage) Trypanosomiasis brucei (T.b.) gambiense infections, before and after treatment with the arsenical trypanocide melarsoprol. We found that patients with late-stage T. b. gambiense exhibit chronically elevated circulating levels of both of these cytokines, and that these levels quickly decline following melarsoprol treatment. These findings confirm that TNF-alpha is involved in the immunopathogenesis of late-stage African trypanosomiasis and suggest that IL-10 may also play an important regulatory role in this disease.