The pattern of skin diseases in the Qassim region of Saudi Arabia: What the primary care physician should know

<b>Background and Objectives :</b>Epidemiological studies to determine the burden of skin diseases are important for proper health care planning. The purpose of this study was to find the pattern of skin diseases in our patients attending university-affiliated dermatologic clinics in the Qassim region. <b>Methods</b> : We conducted a prospective study of all Saudi patients attending the Qassim University Medical College-affiliated dermatology clinics of the Ministry of Health for a period of 12 months from 1 March 2008 to 28 February 2009. <b>Results</b> : The study included 3051 patients comprising 1786 (58.5&#x0025;) males and 1265 (41.5&#x0025;) females. Males outnumbered females (<i>P</i>&lt;.05) (male-to-female ratio, 1.4:1). The mean age (standard error of the mean) of the patients was 25.3 (0.27) years. About 71&#x0025; of the patients were between 5 and 34 years of age. The top five skin diseases were eczema/ dermatitis (19.5&#x0025;), viral infections (16.6&#x0025;), pilosebaceous disorders (14.4&#x0025;), pigmentary lesions (11.2&#x0025;) and hair disorders (7.6&#x0025;). The major disorder in males was viral skin infections (20.0&#x0025;), while eczema/dermatitis (20.7&#x0025;) constituted the most prevalent skin disease in females. Seasonal variations were recorded in cases of pigmentary lesions, papulosquamous disorders and protozoal infections. <b>Conclusion</b> : Infectious skin diseases, eczema/dermatitis, pilosebaceous disorders, pigmentary lesions and hair disorders ranked as the top five skin diseases. Appropriate training programs for diagnosing and managing common skin diseases should be initiated for primary health care physicians and other general practitioners so as to decrease referrals to dermatology clinics

Physiological and biochemical parameters: new tools to screen barley root exudates allelopathic potential (*Hordeum vulgare* L. subsp. *vulgare*

peer reviewedMorphological markers/traits are often used in the detection of allelopathic stress, but optical signals including chlorophyll a fluorescence emission could be useful in developing new screening techniques. In this context, the allelopathic effect of barley (Hordeum vulgare subsp. vulgare) root exudates (three modern varieties and three landraces) were assessed on the morphological (root and shoot length, biomass accumulation), physiological (Fv/Fm and F0), and biochemical (chlorophyll and protein contents) variables of great brome (Bromus diandrus Roth., syn. Bromus rigidus Roth. subsp. gussonii Parl.). All the measured traits were affected when great brome was grown in a soil substrate in which barley plants had previously developed for 30 days before being removed. The response of receiver plants was affected by treatment with activated charcoal, dependent on barley genotype and on the nature of the growing substrate. The inhibitory effect was lower with the addition of the activated charcoal suggesting the release of putative allelochemicals from barley roots into the soil. The barley landraces were more toxic than modern varieties and their effect was more pronounced in sandy substrate than in silty clay sand substrate. In our investigation, the chlorophyll content and Fv/Fm were the most correlated variables with barley allelopathic potential. These two parameters might be considered as effective tools to quantify susceptibility to allelochemical inhibitors in higher plants

Bioassay-guided isolation of allelochemicals from Avena sativa L.: allelopathic potential of flavone C-glycosides

The allelopathic potential of oat (Avena sativa L., var. Argentina, Poaceae, Cyperales) was investigated under field and laboratory conditions. In field trials, oat plants provided an effective control of weeds, showing a species-specific impact: the most abundant weed species, Picris echioides was reduced by 94% in number of individuals. Aerial parts of oat plants, harvested immediately before soil incorporation, were utilized in a bioassay-guided isolation, which was aimed at identifying the phytotoxic compounds in a methanol/water extract of the aerial parts of the plants. Further partitions of extract gave an active n-butanol portion composed of flavonoids and saponins. Phytotoxic activity was detected for the flavonoid fraction, whereas no activity was found for the saponin mixture. Germination of an indicator species, lettuce (Lactuca sativa L.), was completely inhibited at flavonoid concentrations of 6.7, 10.0, and 20.0 mg/mL, and conversely the number of abnormal seedlings was greatly increased from 2% of control to over 96% at concentrations equal to 6.7 and 10.0 mg/mL. Analysis of the flavonoid fraction by ESI-MS techniques identified two components of the mixture as isoorientin 2-O-glucoside and isovitexin 2″-O-arabinoside. Saponins were characterized as avenacoside A, avenacoside B, 26-desglucoavenacoside A, and 26-desglucoavenacoside B. Both flavone C-glycosides and saponins were isolated previously from oat

Cross-resistance patterns of winter wild oat (Avena ludoviciana) populations to ACCase inhibitor herbicides

The level of resistance and patterns of cross-resistance to clodinafop, sethoxydim, and pinoxaden were examined in 12 putative resistant and one susceptible populations of winter wild oat (Avena ludoviciana) collected from Fars Province, in the southwest of Iran. The responses of biomass and length of coleoptiles to the increasing dosages of the three herbicides were determined in both whole-plant and seed bioassays. In the whole-plant bioassay, all 12 putative resistant populations were found to be resistant to clodinafop with resistance ratios (R/S) ranging from 1.76 to &gt;47.04. Most clodinafop-resistant populations exhibited low levels of cross-resistance to sethoxydim. Three highly sethoxydim-resistant populations, F2, S2, and ES4, were slightly resistant to clodinafop. Six populations (M1, M2, F2, S2, S4, and ES4) showed high cross-resistance to pinoxaden with R/S values as large as 10.73 to 40.29. A highly clodinafop-resistant population, M2, was more sensitive to pinoxaden than the susceptible population. The results of the seed bioassay resembled those obtained from the whole-plant experiment suggesting seed bioassay as an inexpensive, rapid method for screening-resistant genotypes