Diversity of hydrolytic enzymes in haloarchaeal strains isolated from salt lake

Production of ten hydrolytic enzymes was qualitatively studied on the haloarchaeal strains isolated from Aran-Bidgol hypersaline lake in the central desert area of Iran. A total of 293 haloarchea strains were selected among 300 extremely halophilic isolated prokaryotes. Accordingly, 142, 141, 128, 64, 38, 16, 7, 3 and 1 archaeal isolates were able to produce DNase, amylase, lipase, inulinase, pullulanase, protease, cellulase, chitinase and xylanase, respectively. None was able to produce pectinase activity. Combined hydrolytic activity was also detected in many strains. A total of 0.3% of the strains showed 6 hydrolytic activities, 0.3% of the strains had 5 hydrolytic activities, 5.4% of the strains presented 4 hydrolytic activities, 25% of the strains presented 3 hydrolytic activities, 28% of the strains presented 2 hydrolytic activities and 18% of the strains presented 1 hydrolytic activity. According to their phenotypic characteristics and comparative partial 16S rRNA sequence analysis, the halophilic strains were all identified as members of family Halobacteriaceae within 12 different taxa from the following genera: Halorubrum, Haloarcula, Natrinema, Halovivax and Natronomonas. Most enzymes production rate was observed in the genera Halorubrum, Haloarcula and Natrinema whereas; there was not any detectable amount of enzyme production in the genera Halovivax and Natronomonas. The most hydrolytic isolate with 6 combinatorial enzyme production belonged to the genus Natrinema. This investigation showed that the extreme halophilic archaea from Aran-Bidgol lake are a potential source of hydrolytic enzyme under stress conditions and may have possess commercial value

Dental erosion and its risk factors in 12-year-old school children in Mashhad

The dental hard tissues might be destroyed by different factors. One is dental erosion defined as the progressive loss of hard dental tissues by a chemical process not involving bacterial action. The purpose of this study was to determine the prevalence of dental erosion and its risk factors in 12-year-old school children. This cross-sectional study was carried out on 483 12-year-old school children in Mashhad, 2007. Dental erosion was recorded for the labial and palatal surfaces of the upper incisors. For measurement purposes, the O'sullivan's index was adopted, and the results were statistically analyzed by T-student and Chi-Square tests. The prevalence of dental erosion was 38.1%, with no significant sex difference. Dental erosion was significantly higher in private school children [P < 0.001] and in underprivileged areas [P = 0.005]. Matt appearance of the enamel was the most prevalent type of dental erosion [21.2% central incisors, 5.2% lateral incisors]. In most of the involved cases, more than half of their surfaces were diagnosed as affected by erosion [24.4% central incisors, 5.2% lateral incisors]. The frequency consumption of carbonated beverages and night drinks illustrated a significant relation with dental erosion [P = 0.01, P = 0.023]. Children who swam professionally in swimming pools had significantly higher dental erosion [P < 0.001]. Based on the findings of this study, individually tailored preventive programs may be recommended to patients and a comprehensive case history should be taken so that all risk factors can be revealed

Rosa Damascena oil: an adjunctive therapy for pediatric refractory seizures

Several investigations have demonstrated that Rosa damascena has an inhibitory effect on the hypothalamus and on pituitary system reactivity in the rat; it ahs also been shown that the essential oil of Rosa damascena has significant antiepileptic effects on pentylentetrazole [PTZ] induced seizures in rats. We aimed at assessing the effects of the essential oil of Rosa damascena when used as an adjunct treatment to treat children with refractory seizures In this double-blind clinical trial, conducted as a pilot study between April 2004 and March 2005, we administered essential oil of Rosa damascena to sixteen children with refractory epilepsy as an adjunct therapy, and evaluated its effects. 16 patients, age range 3-13 years, were enrolled; 56.3% [n=9] girls and 43.8% [n=7] boys. All has been under treatment for 3-6 weeks [baseline phase]. They received either the essential oil or placebo for a period of 4 weeks and in between these periods, they took only their pre-existing antiepileptic drugs for two weeks [washout phase]. The mean frequency of seizures in those using essential oil, showed significant decrease as compared to the controls using placeboes [p=0.00]. It can be concluded that the essential oil of Rosa Damascena has beneficial antiepileptic effect in children with refractory seizures