Acne in schoolchildren: no longer a concern for dermatologists.

OBJECTIVE--To determine the prevalence and severity of acne among schoolchildren in Glasgow. DESIGN--Secondary schools in Glasgow were divided by postcode into five socioeconomic cluster groups. Different numbers of schools were selected at random from the five groups to ensure proportional representation. One class from each registration year of the chosen schools was selected at random and the whole class recruited into the study. SETTING--15 Secondary schools in Glasgow. SUBJECTS--2014 Randomly selected schoolchildren aged 12-17 (5% of total secondary school roll). INTERVENTIONS--None. END POINT--Assessment of facial acne by two independent examiners by a recognised acne scoring system. MEASUREMENTS AND MAIN RESULTS--The prevalence of acne in boys increased from 40% (75/189) at age 12 to 95% (108/114) at age 16, and in girls it increased from 61% (114/187) at age 12 to 83% (136/164) at age 16. On a scale of 0 to 10 only 18 boys (1.8%) and three girls (0.3%) had grades of acne of 1.0 or greater; most of the pupils had grade 0.05-0.375 (minimal) acne. Nine per cent of boys (88/973) and 14% of girls (145/1041) had visited their general practitioner specifically for advice on and treatment for acne; only five pupils (0.3%) had been referred to a dermatologist. CONCLUSIONS--Both the prevalence and severity of acne have decreased over the past 20 years. This has probably been due to improvement of treatment for acne by primary care doctors and the greater availability and use of over the counter preparations for acne.     

Genotyping of Toxoplasma gondii from Rats (Rattus rattus) in Riyadh,Saudi Arabia

Toxoplasma 3 main clonal lineages are designated as type I, II, and III; however, atypical and mixed genotypes were also reported. This study was conducted for detection of Toxoplasma gondii genotypes in rats (Rattus rattus) in Riyadh region, Saudi Arabia. PCR test on T. gondii B1 gene was conducted on ELISA IgM positive samples for confirmation of the infection. However, genetic analysis of the SAG2 locus was performed to determine T. gondii genotypes using PCR-RFLP technique. PCR test on T. gondii B1gene showed that 22 (81.5%) out of the 27 ELISA IgM positive samples have T. gondii DNA. Genotypic analysis shows that, of the total 22 PCR positive samples, only 13 (59.1%) were of type II, 7 (31.8%) were of type III, and 2 (9.1%) were of an unknown genotype. It is obvious that the prevalence of both type II and III is high in rats. No reports have been available on T. gondii genotypes among rats in Riyadh region, and only little is known about its seroprevalence in rats. Future studies on T. gondii genotypes in rats using multi-locus markers is needed in Riyadh region, Saudi Arabia for better understanding of T. gondii pathogenesis and treatment in humans and animals.     

Increasing smoking prevalence among pupils of several Croatian secondary medical schools between 1990 and 2006

Smoking among pupils of secondary medical schools is of particular public health interest because of their role in the health system in the future. The study was part of the survey of smoking among students of Croatian medium medical schools. Data of 3 survey periods were available (1990-2002-2006). Specific smoking trends among 14-18 year olds were examined using odds ratios and multiple regressions. Sex ratios were calculated for each survey period. Daily smoking prevalence in 1990 was 15.9% in boys and 14.1% among girls. Occasional smoking in 1990 occurred among 8.9% of boys and 15.0% of girls. Twelve years after, smoking prevalence increased for daily smoking in boys to 32.9% and among girls to 30.4%. Occasional smoking decreased to 6.3% in boys, and increased to 17.8% among girls. There were no remarkable changes in prevalence from 2002 to 2006. Among adolescents in Croatia, there was high risk for smoking among adolescent population. High smoking rate among pupils of medical schools predicts not only high mortality due to smoking over 20-30 years, but also implicates for bad habit among professional health workers, if no policy interventions were taken.     

Risk of contamination of human and agricultural environment with parasites through reuse of treated municipal wastewater in Riyadh, Saudi Arabia.

Two selected sites in the Riyadh metropolitan area were surveyed for the presence of human pathogenic parasites in treated municipal wastewater (TMWW). A total of 100 samples were collected from both sites at two different seasons, the winter and summer reason. The most common parasites seen were the larvae and adult of Strongyloides sp. There were few Ascaris lumbricoides ova, some of which were embryonated and possibly infective, while the highest frequency of Ascaris ova (100 +/litre) was found at site 2 h, the highest frequency of Strongyloides sp. larvae (36-72/litre) and Strongyloides sp. adult (100 +/litre) were found at sites 2 W and 1 W respectively. The variation between sites and seasonal fluctuations showed a significant difference in parasite per litre. High atmospheric temperatures in the Riyadh area seem to be lethal to most intestinal pathogens similarly the absence of protozoal cysts in the TMWW could be attributed to certain treatment processes and other environmental factors. Data obtained from this study will be valuable in planning for the control of parasitic diseases in particular and public health pathogens in general.     

Aluminum in Saudi children

Aluminum was determined in serum samples obtained from 533 Saudi female pupils aged 6–8 years who attended primary public school in Riyadh City, Capital of Saudi Arabia. The aluminum mean value was 23.21 ± 15.25 g 1^–1 in the range of 5.98–206.93 g 1^–1. Serum aluminum levels of pupils attending the Northern school area were higher than levels found in pupils from other school areas (Southern, Eastern and Central). Renal variables had no correlation with serum aluminum. On the other hand, a significant positive correlation was found between serum aluminium above 49.2 g 1^–1 and urea (r = 0.6, P < 0.002). Although 53% of the screened schools had aluminum in water above the European Union (EU) acceptable limit of 50 g 1^–1, there were no differences in aluminum in water between the four different school areas in Riyadh. Factors such as drinking water, diet and the use of aluminum utensils may have contributed to this result. As there is a bulk of literature which highlights the adverse developmental effects of aluminum on children and infants, it would be advantageous to establish regular aluminum monitoring.     

Ecological significance of floristic composition and life forms of Riyadh region,Central Saudi Arabia

Riyadh region is one of the hardest habitats in Saudi Arabia with a hyper-arid climate. This study was conducted to investigate floristic composition and plant life forms of Riyadh region and their ecological significance. Work aimed to determine the prevailing plant families and biological spectrum of their components that reflects the phytoclimate and adaptation to hyper-arid conditions of the region. Work involved field surveys of different locations in Riyadh region where plant specimens were collected and identified. Collected plant species were then listed according to their families and data were used to assess the contribution of different plant families to the flora of the region. Study of life forms was conducted to classify recorded floristic elements into categories that reflect environmental conditions prevailing in the region. Prevailing plant families were Asteraceae (17.4%), Poaceae (11%), Brassicaceae (9.9%), and Fabaceae (7%). These percentages reflect wide ecological ranges especially for Asteraceae and Poaceae. High presence of species belonging to Astreaceae and Poaceae can be attributed to their adaptation to harsh conditions as well as to effective wind dispersal strategies of their diaspores. While the most frequent life form classes were therophytes with 52%, and chamaephytes with 30%, phanerophytes and hemicryptophytes represented 9% and 8%, respectively. Predominance of therophytes and chamaephytes over other life forms is a response to hyper arid climate with insufficient rainfall and the nature of region of few available microhabitats that can support high percentage of perennials.     

Beetles associated with buried carcasses: potential forensic importance in Riyadh,Saudi Arabia

Burial has a special influence on carrion fauna, which may change the rate of decomposition and so affect postmortem estimates. This study aimed to identify species and succession of beetles on buried remains. From 28 January to 31 May 2021, we examined the Coleoptera on buried and exposed rabbit carcasses, on the campus of the University of King Saud in an area measured around 175 m by 250 m. The area is almost entirely devoid of flora, except for a few acacia trees and some common wild herbs. It is about 1 km away from residential neighborhoods. In total, 165 specimens belonging to 4 families were collected. The Tenebrionidae was the most abundant family, where it formed 52% at a depth of 20 cm and 78% at a depth of 40 cm in the buried carcasses, while the family Dermestidae was the most abundant in the surface carcasses, as it formed 53% of the insects sampled. Type Mesostena puncticollis Solier, 1835 (Tenebrionidae) predominated at exposed carcasses as well as at depths of 20, 40 cm and while type Dermestes frischii Kugelann, 1792 (Dermestidae), predominated at depth of 40 cm and exposed carcasses, and type Saprinus chalcites (Illiger, 1807) (Hisiteridae) at depth of 20 only. These findings are possibly useful in forensic investigations involving buried bodies in Riyadh, Saudi Arabia.     

Incidence of leukaemia and other cancers in birth and schools cohorts in the Dounreay area.

OBJECTIVE--To determine whether a raised incidence of leukaemia in the Dounreay area occurred in children born to local mothers (birth cohort) or in those who moved to the area after birth (schools cohort) and also whether any cases of cancer have occurred in children born near Dounreay who may have moved elsewhere. DESIGN--Follow up study. SETTING--Dounreay area of Caithness, Scotland. SUBJECTS--4144 children born in the area in the period 1969-88 and 1641 children who attended local schools in the same period but who had been born elsewhere. MAIN OUTCOME MEASURES--Cancer registration records linked to birth and school records with computerised probability matching methods. RESULTS--Five cancer registrations were traced from the birth cohort compared with 5.8 expected on the basis of national rates (observed to expected ratio 0.9, 95% confidence interval 0.3 to 2.0). All five cases were of leukaemia (2.3, 0.7 to 5.4). In the schools cohort three cases were found (2.1, 0.4 to 6.2), all of which were of leukaemia (6.7, 1.4 to 19.5). All eight children were resident in the Dounreay area at the time of diagnosis; thus no cases were found in children who were born in or had attended school in the study area but who subsequently moved away. CONCLUSION--The raised incidence of leukaemia in both the birth and schools cohorts suggests that place of birth is not a more important factor than place of residence in the series of cases of leukaemia observed near Dounreay area.     

Distribution, biomass and primary production of an Ahnfeltia tobuchiensis (Ahnfeltiales, Rhodophyta) population in the Bay of Izmena, Kunashir Island

Regularities of distribution and primary production of an Ahnfeltia tobuchiensis (Kanno et Matsubara) Mak. population, an agar-containing red alga, were studied in the Bay ot Izmena. Experiments were conducted in a flow-through system under conditions similar to algal habitats. The population of A. tobuchiensis unattached to the ground may be from a few centimeters to as much as 1 m thick. It has been shown that only the upper part of a stratum 15–20 cm thick receives a sufficient amount ot light to realize its production potential. While 15–20% of photosynthetically active radiation (PAR) of that falling on the water surface reaches the stratum surface, only 0.1% of PAR from that falling on the water surface penetrates through stratum 15 cm thick. It has been shown for A. tobuchiensis that its photosynthetic rate curve during the daytime mainly follows the PAR intensity curve. The highest values of photosynthetic rate have been measured in the afternoon when PAR reaches its maximum. It is noted that a stratum 15–20 cm thick has peak values ot net primary production (NPP) which averages 3.2 g C m^?2 day^?1. The total area of A. tobuchiensis population was 23.4 km², and its biomass was 125 000 tons in this area. On average, the NPP of the A. tobuchiensis population made up in summer and in autumn was 46.8 and 25.0% of its biomass, respectively.     

杭州西溪国家湿地公园不良旅游行为及其对景区环境的影响

通过现场调查、数据收集和相关性分析,对2006年西溪国家湿地公园不良旅游行为及其对景区环境的影响进行了分析.结果表明：2006年,研究区采摘、践踏和乱扔垃圾三类不良旅游行为的发生概率分别为6.5%、10.3%和12.6%;采摘行为的发生概率主要与沿途的植被类型有关;重度践踏的面积与旅游者进入景区后的游览距离呈线性负相关关系;研究区游客日人均产生的垃圾量为782 g,且桶外垃圾量占13.6%;研究区每周的日均游客量、每周游客量和每月游客量的波动性表明该区接待游客的季节性明显,旺季有连续数日的超负荷接待.超负荷接待导致不良旅游行为增多,景区水质由于排污设施完善而没有受到影响.     

Degraded ecosystems in China: status, causes, and restoration efforts

The total area of China is about 9.6 million km². Among the terrestrial ecosystems, cropland area is about 1.33 billion ha, 78% of which is degraded land; forestland area is about 1.75 billion ha, 72% of which is forest deterioration; grassland area is 3.99 billion ha, 90% of which has already degraded. Derelict mining land area is about 6 million ha, which is increasing by 12,000 ha/year. So far, only 8% of the total derelict mining land area has been reclaimed. A total lake area of 1.3 million ha has been lost since 1950; 50% of the coastal wetlands has been reclaimed. The mangrove area has declined from 40,000 ha in 1957 to 18,841.7 ha in 1986. With a total of 0.18 billion ha of water area, over 50% of it has been polluted to type III–V in terms of the Chinese Water Quality Standard Classification System. Oceanic area is about 4.73 billion ha, over 1.6% of which is also polluted. Environmental pollution is very severe in China, especially the environmental problems in rural and agricultural areas. Water resource is severely lacking and most river ecosystems are facing deterioration. The oceanic environmental problem is still fearful. Water and soil eroded areas have been increasing year after year and have become the most severe environmental issue in China. In addition, land desertification, prairie deterioration, and land salination have been increasing at an accelerating rate. Forest function has weakened and the current environment in derelict mining land areas are headachy. Biodiversity has been destroyed badly. The reasons for the deterioration of China’s environment are diverse, such as the pressure of a large population, industrialization, and its markets. The deterioration of the ecological index has already affected the current economic index and prospective economic growth directly and obviously.     

Chemical sensitivity: Risks in schools

Congressional interest in the health and safety of school children led to a request for the Congressional Office of Technology Assessment (OTA) to assess the available data on hazards to children in schools in the United States. In this report, OTA identified the major hazards thought to pose a risk of illness in schools. Illnesses were limited to those arising from environmental hazards, which were grouped in this report as school materials and indoor air. Few data have been collected on any of these hazards in school. OTA could not identify a functional national reporting system for environmental ?hazards in schools. The absence of studies documenting in‐school illnesses or exposure in school presents fundamental gaps in the data needed to assess risks nationwide.     

Cigarette waste: Assessment of hazard to the environment and health in Riyadh city

Cigarette waste/litter is considered a major environmental contamination problem worldwide as trillions of cigarettes are smoked worldwide and a large part of that, cigarette waste, is disposed of in the open areas including roads, parks, and streets, etc. cigarette litter is the most commonly found litter. It is mainly cigarette filter, made of cellulose acetate, and unburnt part of the tobacco filler. Filters from smoked cigarettes contain a significant amount of tar trapped in it. The tar contains thousands of chemicals and heavy metals. Both of these organic and inorganic constituents have been reported to be toxic to humans and cause a variety of diseases including inflammatory lung diseases, cardiovascular diseases, and cancers. Cigarette litter is a significant environmental concern as the chemicals and heavy metals can leach into the soil or water sources and pose threat to animals and plants, from there they can enter into the food chain as well. Several reports indicate toxicities to aquatic and terrestrial animals as they consumed cigarette litter. In the present investigation, cigarette litter was collected from 28 randomly selected locations in the Riyadh city to assess the risk to the environment. Cigarette litter, in the form of cigarette butts, was collected, counted, weighed and analyzed for heavy metal content. Data indicate the presence of a significant amount of cigarette litter on roadsides, streets, and parks in the Riyadh city. However, the investigation had its limitations as it did not focus on the absolute amount of cigarette litter vs the time. It also did not consider the amount of cigarette litter percent in the total waste discarded. The investigation presents the results of the screening of the cigarette litter present on the Riyadh city roads, streets, and parks. The findings raise concerns regarding the hazards the cigarette litter poses to the environment and human health. The investigation sheds the light on this unexplored aspect of smoking-associated issues in the Kingdom of Saudi Arabia.     

Blood parasites of livestock in certain Regions in Saudi Arabia

Blood samples from camels, sheep, goats and cattle from six Regions in Saudi Arabia were examined for blood parasites. Asir Region camels were disinfected while those of the Eastern, Jazan, Northern Frontiers, Riyadh and Tabouk Regions were infected with Trypanosoma evansi (5–40%), those of Riyadh and the Eastern Regions were infected with Dipetalonema evansi (1–6%) and those of the Eastern, Jazan and Riyadh Regions were infected with Eperythrozoon species (8–20%). Sheep and goats of all tested regions were infected with Theilaria hirci (4–20% and 6–14%, respectively), Theilaria ovis (5–19% and 6–24%, respectively) and Eperthrozoon ovis (2–9% and 2–8%, respectively). Sheep of the Eastern and Northern Frontiers Regions were also infected with Anaplasma ovis (2%) and also those of the Eastern Region were infected with Babesia motasi (4%) as well. Cattle of Asir and Eastern Regions were infected with Anaplasma marginale (1–3.4%) and those of the Eastern, Jazan and Riyadh Regions were infected with Theileria annulata (11.3–25%) and Eperthrozoon wenyoni (1–4%). Moreover, Jazan cattle were infected with Babesia bigemina (6%) and a benign Theileria species (27%). Some of these parasites are recorded in new localities indicating that they are spreading in the country. Also, this is the first report in Saudi Arabia of D. evansi in camels, A. ovis and B. motasi in sheep and A. marginale and B. bigemina in cattle. These parasites may be introduced into the country with infected livestock infested with the vectors of these parasites. The suspected vectors of the detected parasites in Saudi Arabia is discussed. Follow up surveys of blood parasites are recommended to assess their distribution and infection rates in the livestock of all Regions of Saudi Arabia, to make plans for control measures against their vectors.     

Prevalence of Enterobius vermicularis infection and preventive effects of mass treatment among children in rural and urban areas, and children in orphanages]

An epidemiological study and mass treatments of Enterobius vermicularis infection among children near Wonju area of Kangwon province were carried out. The children were divided into 4 groups according to their residing localities; children in the mountainous area, rural area, urban area and in orphanage. They were examined by adhesive cellotape anal swab technique, and egg positive rates were obtained. The rates of egg reduction and re-infection rates after repeated mass treatments were also observed. The results obtained were as follows: 1. The overall egg positive rate of E. vermicularis in the first screening was 19.9% (251 out of 1,262 examinees; 19.7% in males and 20.1% in females). The positive rates were 13.0% in the mountainous area, 11.9% in the rural area, 15.1% in the urban (medium-sized) area and 61.9% in orphanages. 2. The highest positive rates were observed in the kindergarten children, and 1st and 2nd grade children of primary schools (26.2-32.2%), and the lowest rate (13.6%) in 6-year grade children of primary schools. 3. Cumulative detection rates from 3 repeated anal swabs at 4-5 days interval were higher (70.8%) than those from single anal swabs (50.0-59.2%). 4. Out of the examinees who showed the highest cumulative positive rate (70.8%), about 39.2% were consecutively positive in 3 anal swabs. Among different groups of children, the higher the total egg detection rates (87.5%), the higher the consecutive positive rates (71.9%). 5. A total of 2,609 (male: female = 1:12.4) worms were collected from 17 egg-positive cases treated with anthelmintics. The mean number of worms per child was 153 (range: 4-824).(ABSTRACT TRUNCATED AT 250 WORDS)     

草原区矿产开发对景观格局和初级生产力的影响——以黑岱沟露天煤矿为例

煤炭是我国的主要能源,大型露天煤矿的开发推动了地区经济与社会的发展,但同时也引发了区域生态环境问题。因此,探讨矿产开发对区域景观格局的影响,并阐明景观格局动态与生态系统初级生产力的关系,对生态环境的保护具有重要意义。以内蒙古草原区的黑岱沟露天煤矿为例,利用3S(RS、GIS和GPS)技术,在野外实地调查的基础上,分析了1987年以来矿产开发导致的土地利用/覆盖变化、景观格局动态及其与生态系统初级生产力之间的关系,主要结果如下:(1)提出了界定最适研究区范围的方法,认为沿矿区边界向外建立10 km的缓冲区是该研究最适研究区域的大小;(2)草地和耕地是研究区主要的土地利用/覆盖类型,但是在过去20多年间其面积在逐渐减少,而工矿仓储用地及住宅用地面积在急剧增加;(3)矿产开发导致景观格局发生变化,并且在两种不同的空间尺度(研究区和矿区)上表现出总体变化趋势的一致性,但在后期有较大差异;(4)初级生产力变化呈现下降趋势,并且矿区的降低更为突出;(5)以生长季降水量为控制因子的偏相关分析表明,景观配置(平均斑块周长面积比、景观形状指数)与初级生产力呈正相关关系,在研究区尺度上尤其显著,但在矿区尺度上,景观结构组成(斑块密度、均匀度指数和多样性指数)更为重要,与初级生产力呈显著负相关;(6)受复垦规模和演替进程的影响,局限在矿区排土场上的植被重建尚不能改变研究区尺度景观-生态系统初级生产力之间的关系。可见,景观格局的变化以及景观格局与生态系统初级生产力之间的关系均存在尺度依赖性。     

Sleep Duration and Quality Associated With Obesity Among Arab Children

The link between sleep duration and obesity has been well established in adults, but several epidemiological studies revealed inconsistent findings in adolescents and younger children. This study aimed to investigate the relationship between sleep length and obesity in Saudi students. A total of 5,877 Saudi students, boys (55.2%) and girls (44.8%), aged between 10 and 19 years were randomly selected from elementary, intermediate, and secondary schools in different regions of Riyadh. A questionnaire on sleep behaviors was given. Anthropometry included BMI and waist and hip circumferences. Sleeping ≤7 h significantly increased the risk of obesity in both boys and girls (all age categories) (odds ratio = 1.25–1.38, 95% confidence intervals = 1.02–1.89). Overall prevalence of overweight and obese were higher among those sleeping intermittently (18.68%) than those sleeping continuously (14.5%) (P = 0.024). Short sleep duration and poor sleep quality are significantly associated with obesity among Arab youth. Further studies need to employ more objective measures of sleep, such as actigraphy, and examine the mechanism of these associations.     

Control of urinary schistosomiasis on Zanzibar (Unguja Island): a pilot evaluation of the educational impact of the Juma na Kichocho health booklet within primary schools

To improve health education within primary schools, the health education booklet "Juma na kichocho" was evaluated during a study within 5 schools using key-informant questionnaires that recorded children's knowledge and attitude (KA) towards schistosomiasis before and after daily structured-use of booklets. A total of 229 schoolchildren (114 boys : 115 girls) of between 11 and 15 years of age were interviewed and re-assessed after a working school week. Existing and putative booklet-induced changes in KA scores for schistosomiasis were compared directly against equivalent KA scores for malaria. In total 47.4% of children were already aware that schistosomiasis was a water-borne disease while only 10.5% knew of its exact aetiology; after booklet intervention these levels increased to 54.6 and 15.7%, respectively. The majority of children still failed, however, to realise that re-infection could take place soon after treatment. While a positive increase was observed for children's total KA questionnaire scores for both malaria and schistosomiasis after booklet intervention, these were not statistically significant. In the context of control, further educational efforts are needed to promote and guide behavioural change, especially in relation to reduction of environmental water contact.     

DNA ploidy-characteristics of human malignant melanoma analysed by flow cytometry and compared with histology and clinical course

Flow cytometric analysis of nuclear DNA content is valuable for indicating ploidy- and proliferation abnormalities in surgically removed human malignant melanomas. In 35 primary cutaneous melanomas, 20 metastases of melanoma in skin and lymph nodes, and 16 nevi the DNA distribution was analyzed by flow cytometry and compared with a variety of histological parameters and the subsequent clinical course. Heteroploid DNA distributions with increased polyploid or aneuploid fractions were found in 26 primary melanomas (74%), 14 metastases (70%), and 4 nevi (25%) indicating tumor clones with an abnormal nuclear DNA content. Three or more cell clones in a single biopsy was found in 10 primary melanomas, 2 metastases, and 1 nevus. The frequency of heteroploidy was significantly higher in primary and secondary melanomas than in nevi (p less than 0.001) and was correlated significantly with a high mitotic activity (p less than 0.002), marked nuclear pleomorphism (p less than 0.01), large nucleoli (p less than 0.01) and a thickness of the primary melanoma of more than 2.25 mm (p less than 0.02). Such histologic findings in malignant melanomas have been shown previously to be correlated with a bad prognosis. No significant correlation was found between heteroploidy and the histologic type of melanoma or the level of invasion. A 2-year clinical follow-up showed that more patients died from melanoma if the DNA distribution in the primary or secondary melanoma was heteroploid (6/26; 23% and 8/13; 62% respectively) than if it was diploid (0/9; 0% and 2/5; 40% respectively). However, the differences were not statistically significant. It is concluded that heteroploidy 1) is not an absolute criterion of malignancy, 2) is significantly correlated with histologic features indicating marked cellular anaplasia, and 3) is apparently correlated with a bad prognosis.