No abstract

Although cysteinyl-leukotriene receptor antagonists were recently approved for use in allergic rhinitis (AR), there has been no study to date investigating their application in children. The aim was to evaluate whether montelukast provides any benefit in nasal allergen challenge-induced symptoms in children, and whether it could improve the control provided by an antihistamine during pollen season. Two randomized studies, one a double-blind, placebo-controlled, nasal allergen challenge study and one an open-label, cross-over, parallel-group clinical study, were performed in 18 (11.7+/-0.7 years) and 32 children (10.5+/-0.5 years), respectively, with grass pollen allergy. In the first study, the effect of a single dose of montelukast and its combination with loratadine were compared with placebo on nasal responses induced by allergen challenge. In the second study, the additive effect of montelukast to loratadine was tested in an open-label cross-over clinical study. In the challenge study, early-phase and late-phase nasal reactions peaked at 15 min and 4 h after the challenge respectively. During the early phase, combination improved total nasal symptoms (p=0.004) during the first hour and sneezing (p=0.012) at 15 min compared with placebo group. During the late phase, montelukast (p=0.017) and combination (p=0.011) caused less nasal obstruction at 4 h and combination caused less sneezing at 6 h (p=0.015). In the clinical trial, montelukast provided protection on seasonal increase in pulmonary symptoms [0 (0, 14) vs. 6.5 (0, 27.7); p=0.016] and on the decrease in FEF25-75 [-0.09 (-0.34, 0.17) vs. -0.28 (-0.66, 0.02); p=0.002]. However, there was no improvement in nasal symptoms and flows. Although we showed protection against nasal challenge-induced congestion with montelukast, we were not able to show the same in the clinical study possibly because of low pollen counts and mildness of the symptoms of the patients with AR. However, montelukast provided better control of pulmonary symptoms and protection from seasonal decrease in lung function, indicating its potential therapeutic benefit in children with AR.

Pollen plays an important role in the development and exacerbation of allergic diseases. We aimed to investigate the days with highest counts of the most allergenic pollens and to identify the meteorological factors affecting pollen counts in the atmosphere of Ankara, Turkey. Airborne pollen measurements were carried out from 2005 to 2008 with a Burkard volumetric 7-day spore trap. Microscope counts were converted into atmospheric concentrations and expressed as pollen grains/m(3). Meteorological parameters were obtained from the State Meteorological Service. All statistical analyses were done with pollen counts obtained from March to October for each year. The percentages of tree, grass and weed pollens were 72.1% (n = 24,923), 12.8% (n = 4,433) and 15.1% (n = 5,219), respectively. The Pinaceae family from tree taxa (39% to 57%) and the Chenopodiaceae/Amaranthaceae family from weed taxa, contributed the highest percentage of pollen (25% to 43%), while from the grass taxa, only the Poaceae family was detected from 2005 to 2008. Poaceae and Chenopodiaceae/Amaranthaceae families, which are the most allergenic pollens, were found in high numbers from May to August in Ankara. In multiple logistic regression analysis, wind speed (OR = 1.18, CI95% = 1.02-1.36, P = 0.023) for tree pollen, daily mean temperature (OR = 1.10, CI95% = 1.04-1.17, P = 0.001) and sunshine hours (OR = 1.15, CI95% = 1.01-1.30, P = 0.033) for grass pollen, and sunshine hours (OR = 3.79, CI95% = 1.03-13.92, P = 0.044) for weed pollen were found as significant risk factors for high pollen count. The pollen calendar and its association with meteorological factors depend mainly on daily temperature, sunshine hours and wind speed, which may help draw the attention of physicians and allergic patients to days with high pollen counts.

In this paper, chromosome number, karyotype and pollen morphology of Centaureagoeksunensis Aytaç & H. Duman, described in 2005, are studied for the first time. Centaurea goeksunensis is found to be tetraploid (2n=4x=60). This is the second record of polyploidy in Centaurea sect. Psephelloideae (Boiss.) Sons. The basic chromosome number of C. goeksunensis was found to be x=15 and the haploid karyotype formula is 18 m+10 sm+2 st. The pollen grains of C. goeksunensis were found to be radially symmetric, isopolar and tricolporate. They are intersemiangular in polar view and prolate–sphaeroidal in equatorial view. The exine is thickened at the poles.

Palynological characteristics of 11 taxa belonging to the genus Arenaria (Caryophyllaceae) have been examined. Pollen grains in the pollen slides, which were prepared according to the method of acetolysis, morphological features were determined with light microscope and also with SEM, then microphotographs of pollens were taken. Morphological examinations were performed on the part of the work carried out with light microscope, pollen sizes, pore sizes and numbers were observed to vary between taxa. The pollen type of the studied taxa is pantoporate (periporate), pollen shape is prolate spheroidal, exine structure is subtectate, the ornamentation is microechinate-perforate. The pores are covered with operculum and the surface of the operculum is microechinate. According to the results of the study, pollen definitions of the taxa were made. Based on different palyno-morphological characters, a taxonomic key was develop for quick and accurate identification. The results of the study corroborate that morphological features, such as axes, aperture number, Plg, and Plt diameter and distance between pores, show differences which can be taken into consideration in the systematic discrimination within the groups, and also for discrimination of the taxa in the genus Arenaria.