bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exercise‐induced bronchoconstriction among Malay schoolchildren
Authors: Zainudin Norzila Mohamed , Aziz Bilkis Abdul , Haifa A. L. , Deng Cheng Teik , Omar Azizi Hj 
Published: March 2003

Objective: Exercise‐induced bronchoconstriction (EIB) may be demonstrated in 60–70% of asthmatic children in temperate climates. In areas of high humidity it is postulated to be low. The aim of the study was to determine the prevalence of EIB in a population of schoolchildren with wheezing, living in the humid tropical climate of Kuala Lumpur, Malaysia.Method: We performed a cross‐sectional study using the International Study of Asthma and Allergies in Childhood questionnaire to identify 7–12‐year‐old Malay children with asthma symptoms from a primary school in central Kuala Lumpur. Sixty‐five of 76 children with ‘ever wheeze’ performed an exercise challenge test successfully in an uncontrolled environment. A random sample of 80 schoolchildren with no history of wheeze were similarly tested as controls. The relative humidity and temperature were recorded. A fall of > 15% was considered as clinically important.Results: The prevalence of EIB in schoolchildren with ‘ever wheeze’ was 47.7%. The prevalence of EIB in children with ‘current wheeze’ was 51.6%. The prevalence of EIB in controls was 7.5%. The relative humidity during the study ranged from 41 to 90%. There was no significant relationship between different humidity levels and EIB (P = 0.58, regression analysis).Conclusion: This study demonstrates that EIB is present in asthmatic children despite the highly humid tropical environment.
Cyclic stretch upregulates interleukin‐8 and transforming growth factor‐β1 production through a protein kinase C‐dependent pathway in alveolar epithelial cells
Authors: YAMAMOTO HIROYUKI , TERAMOTO HIDEMI , UETANI KOHSAKU , IGAWA KATSUTOSHI , SHIMIZU EIJI 
Published: March 2003

Objective: Positive‐pressure mechanical ventilation can injure the lung, causing oedema and alveolar inflammation, which is termed ‘ventilator‐induced lung injury’ (VILI). We postulated that cyclic stretch upregulates the release of cytokines, which may cause lung damage, and explored which cytokines were released after cyclic stretch in type II alveolar epithelial cells (A549).Methodology: To test this hypothesis, A549 cells were cultured on a silicoelastic membrane and interleukin (IL)‐1β, IL‐8, granulocyte–macrophage colony stimulating factor, activin, transforming growth factor (TGF)‐β1, insulin‐like growth factor‐2 and tumour necrosis factor‐α mRNA and protein were assessed after stimulation of the cells by cyclic stretch.Results: Cyclic stretch induced activation of protein kinase C and resulted in the release of IL‐8 and TGF‐β1 from A549 cells.Conclusions: The release of IL‐8 and TGF‐β1 from alveolar epithelial cells may be a contributing factor in alveolitis associated with VILI.
A relatively high prevalence and severity of asthma, allergic rhinitis and atopic eczema in schoolchildren in the Sultanate of Oman
Authors: AL‐RIYAMI Bazdawi M. S. , AL‐RAWAS Omar A. S. , AL‐RIYAMI Asiya A. , JASIM Lyla G. , MOHAMMED Ali J. 
Published: March 2003

Objectives:  Although asthma, allergic rhinitis and eczema are among the most common chronic diseases in children worldwide, there is very limited information about the burden of these conditions in Oman. The aim of this study was to determine the prevalence and severity of symptoms of asthma, allergic rhinitis and eczema in Omani schoolchildren using the International Study of Asthma and Allergies in Childhood (ISAAC) Phase I questionnaire.Methods:  An Arabic version of the ISAAC Phase I questionnaire was completed by parents of 3893 children aged 6–7 years and self‐completed by 3174 children aged 13–14 years, randomly selected from a nationwide sample of public schools.Results:  The prevalence rates of reported diagnoses of asthma, allergic rhinitis and eczema were higher in older children (20.7%, 10.5% and 14.4% compared with 10.5%, 7.4% and 7.5%, respectively, in young children). In young children, 277 were current wheezers and of these 40.8% had sleep‐disturbing wheeze at least once a week and 45.1% had speech‐limiting wheeze during the past year. Similarly, 283 older children were current wheezers, and of these 30.0% had sleep‐disturbing wheeze at least once a week and 37.5% had speech‐limiting wheeze during the past year. Exercise‐induced wheeze was higher in older children (19.2%vs 6.9%; P < 0.001). Allergic rhinitis and eczema were also associated with significant sleep disturbance and limitation of activity in both age groups.Conclusion:  Allergic conditions in Omani schoolchildren are common and associated with significant morbidity. Further research is required to identify the local risk factors for allergy to allow better understanding and management of these conditions.
From pollen dynamics to adaptive dynamics
Authors: De Jong Tom J. 
Published: March 2003

AbstractOn plants with many flowers, bumblebees tend to visit more flowers in sequence. This induces pollen transfer between flowers on the same plant (geitonogamy). Consequently, in self‐compatible plants the selfing rate increases with the number of simultaneously open flowers on the plant, and pollen export to other plants in the population can be a decelerating function of the number of flowers. I argue that geitonogamy is important in relation to two phenomena. First, it may explain the low number of seeds per flower and the size‐dependent sex allocation observed in some species. Applying sex allocation theory to the boraginaceous Cynoglossum officinale and Echium vulgare shows that hermaphroditism is stable in both species. The predicted evolutionarily stable values for seeds per flower are close to observed values in the field. The model generally predicts that seeds per flower increase with plant size. This prediction is fine for C. officinale but E. vulgare defies the theory. Second, geitonogamy is important in the evolution of dioecy, as already suggested by Darwin. With abiotic pollination the export of pollen to other plants is likely to be proportional to the number of flowers produced, while it decelerates in animal‐pollinated plants. Dioecy can then evolve gradually in a species with abiotic pollination, provided that inbreeding depression exceeds 50%, geitonogamous selfing increases with the number of flowers and that genetic variation exists. With complete pollen discounting as in the models of geitonogamous pollination by animals, hermaphroditism is always stable. The model explains Darwin’s observation that dioecy is more common in wind‐pollinated species and in species in which individuals are large, reproducing with many flowers.
Environmental factors and survival strategies of annual plant species in the Negev Desert, Israel
Authors: Gutterman Yitzchak 
Published: March 2003

AbstractSeveral environmental factors have pronounced influences on the complementary sets of survival strategies, at different stages of the plant life cycle, of some of the most common annual plants in the Negev Desert, Israel. Plasticity of seed germination may spread germination over time and thus reduce the risk to species survival. This plasticity may be affected by day length during seed development and maturation and by position of seeds on mother plants. Post‐seed maturation dry storage temperatures may affect the duration of after‐ripening. The tiny, dust‐like seeds produced by some plants that are dispersed by wind after maturation may escape massive seed predation and remain in large seed banks in the soil. Seeds of other species are protected in lignified structures in aerial seed banks on dead, dry, lignified mother plants. Seed dispersal strategies from these aerial seed banks by rain may also prevent massive seed collection by animals. The ‘cautious’ or ‘opportunistic’ germination strategy and seedling drought tolerance may increase seedling survival in many of the plant species under the unpredictable amounts and distribution of rain in these desert areas. Factors such as amount of rain, temperature, relative humidity, time of the beginning of soil wetting (day or night), seed size and history and the depth of seeds in the soil may affect germination percentages. Day length and soil water content during plant development may have a pronounced influence on plant age at first flowering, seed yield and plant life span.
Smoke as a germination cue
Authors: Staden Johannes Van , Brown Neville A. C. , Jäger Anna K. , Johnson Tafline A. 
Published: March 2003

AbstractFire is a major environmental selective force that influences plant communities in many parts of the world. Reproductive strategies have evolved as adaptations to the various factors generated by, and/or associated with, fire. This is particularly true for seeds, in which strategies have evolved that respond to both the physical and chemical germination cues that may be associated with fires. Some of these cues are clearly of a primary nature, while others may play a secondary and/or highly specific, or even permissive, role in the germination process. Clearly, there must be considerable interaction between the physical and chemical cues generated by wild fires. Smoke is the most striking chemical factor. Smoke released from burning vegetation contains a chemical signal that triggers germination of both fire climax and non‐fire climax species from different parts of the world. It is used in horticulture to stimulate seed germination of wildflower species and can break dormancy and improve germination of vegetable crops, such as lettuce and celery. Smoke can be applied to seeds immediately before sowing, or the seeds may be pretreated and stored until conditions are appropriate for sowing. Both smoke and aqueous smoke‐water are active in this respect. The active constituent(s) is volatile, thermostable, water soluble and long‐lasting in aqueous solution and in the soil. Attempts to identify the active compound(s) and to determine the mechanism(s) of action have been unsuccessful. Smoke treatment is effective on many seeds that have a light requirement for germination. A very clear concentration effect, resembling that of hormonal responses has been established with aqueous smoke solutions. Smoke extracts interact with gibberellins, cytokinins, abscisic acid and ethylene in photoblastic and in thermodormant seeds. However, despite these interactions it remains questionable whether smoke acts via hormones in stimulating seed germination. There is a clear connection between smoke and life history traits. Smoke may well be the overriding trigger for germination in relation to specific growth habits, regeneration strategies, seed storage, seed sizes, dispersal modes and structures for a large number of species growing in fire‐prone habitats. It is becoming increasingly clear that smoke as a germination (or growth regulating) cue must have evolved as part, or as a consequence of fire, as an evolutionary factor. As such, it is probably a very old development and serves as an additional protection mechanism to ensure germination at optimal times for seedling survival.
‘Thawing’ of ‘frozen’ variation in an adventive, facultatively apomictic, clonal weed
Authors: Chapman Hazel , Brown Jennifer 
Published: March 2003

AbstractRadiation of adventive, sexually reproducing organisms into a new environment has been well documented, but less is understood about the patterns and processes of geographical radiation in adventive species with uniparental reproduction (parthenogenesis or apomixis), usually associated with ‘frozen’ variation within maternal lineages. In this study we have used Pilosella officinarum to test the hypothesis that sexual reproduction becomes important in the radiation of adventive facultatively apomictic species. Within its native Europe P. officinarum is an extremely variable species, with eight subspecies and a range of ploidy levels. Pentaploids are always apomictic. However, early chromosome analyses of New Zealand adventive populations, carried out during the 1980s, discovered only pentaploid, apomictic clones. Similar observations were made in an early 1990s study of the same sites. Since then, a range of ploidy levels, including aneuploids, and a plethora of morphological variation, has been recorded. In this paper, we use a combination of image analysis and chromosome counts to show that sexual reproduction has become an important avenue for adaptive radiation in New Zealand populations of P. officinarum. Current populations probably comprise complex among‐subspecies hybrids, and possibly among‐species hybrids, which are at least partially capable of sexual reproduction and various forms of back‐crossing. Somatic mutation may also play an important role in creating morphological variation. DNA fingerprinting did not contribute to this study because this technique failed to distinguish between morphological types observed in the field.
Effect of socioeconomic status on the blood pressure in children living in a developing country
Authors: Soylu Alper , Kavukçu Salih , Türkmen Mehmet , Çabuk Nur , Duman Murat 
Published: March 2003

Abstract Background: Lower socioeconomic status has been reported to favor higher blood pressure both during childhood and adulthood, because obesity is more prevalent among this population. The aim of the present study was to evaluate the effect of socioeconomic status on blood pressure and prevalence of obesity among children living in a developing country.
Methods
: Prepubertal primary school children (total number 1024, male/female ratio 513/511, mean age 10.32~0.60 years) living in Izmir, a metropolis of Turkey, were enrolled in the present study. The children were classified into three groups according to the locations of their schools as those from the well‐developed (WD; n=290), moderately developed (MD, n=356) and underdeveloped (UD, n=378) areas. Body mass index (BMI), ratio of BMI to the 50th percentile value of BMI for that age (BMI%) and systolic (SBP) and diastolic blood pressures (DBP) were determined in all children. Each socioeconomic group was subdivided into three subgroups with respect to BMI% as those with less than 90% (SG(<90)), 90–110% (SG(90–110)), and more than 110% (SG(>110)). Then, mean SBP and DBP in each subgroup of the WD, MD and UD groups were compared with the corresponding blood pressure values of each other to evaluate the effect of socioeconomic status on the blood pressure. In addition, the SBP and DBP of each subgroup were compared with other subgroups within that group to evaluate the effect of BMI on blood pressure.
Results
: The BMI and BMI% of the UD group were significantly lower than that of the WD and MD groups (P<0.05). In addition, the number of children with a BMI of more than 95% for their age was significantly lower in the UD group compared with the WD and MD groups (1.7, 1.9 and 0.5% in the WD, MD and UD groups, respectively, P<0.05). The SBP and DBP were positively correlated with BMI% in each group and in all of the subjects cumulatively (r=0.26, P<0.001 for SBP and r=0.34, P<0.001 for DBP). The SBP and DBP were significantly higher in SG(>110) than in SG(90–110) and were also higher in SG(90–110) than in SG(<90) in each group. Mean DBP values in all subgroups of the MD and UD groups were significantly lower than the respective subgroups of the WD group. The SBP of SG(<90) and SG(90–110) of the UD group were significantly lower than those of the corresponding subgroups of the WD and MD groups.
Conclusion
: Obesity is not more prevalent among the children of lower socioeconomic classes in Turkey as a developing country. In addition, independent of anthropometric structure, DBP and SBP were shown to be related to the socioeconomic status in childhood age groups and both values were determined to decrease in accordance with a decrease in the socioeconomic level.
Coronary risk factors in Turkish schoolchildren: Randomized cross‐sectional study*
Authors: Uçar Birsen , Kiliç Zübeyir , Çolak Ömer , Öner Setenay 
Published: March 2003

AbstractBackground: There is a strong association between the extent of atherosclerotic lesions in aorta and coronary arteries and antemortem risk factors in children and young adults. Cardiovascular diseases are the most common cause of death in adults in Turkey. However, the data about the extent of coronary risk factors in Turkish children is very limited. The aim of this cross‐sectional study was to investigate the prevalence of coronary risk factors in Turkish schoolchildren living in Eskişehir, Turkey.Methods: A randomly selected population of 4026 schoolchildren, aged between 7 and 18 years, residing in urban and rural parts of Eskişehir were evaluated for coronary risk factors, using previously predicted risk threshold values.Results: Hypertension was found in 4.8% of the girls and 3.8% of the boys, 14.9% of the girls and 10.8% of the boys had abnormal lipid values, 18.2% of the girls and 26.4% of the boys had elevated total body fat percentages, 20.7% of the girls and 14.5% of the boys had physical inactivity and 3.8% of the girls and 11.4% of the boys were regular smokers. Urban children had higher rates of hypercholesterolemia; however, rural children had higher rates of physical inactivity. When the modifiable risk factors were considered, excluding family history, 47.7% of the children had at least one risk factor and 11.7% of them exhibited two or more risk factors.Conclusions: Turkish schoolchildren living in Eskişehir had considerably high levels of coronary risk factors. The interventional measures established in childhood, during which the lifestyle and habits responsible for coronary heart diseases are acquired, will be very effective for preventing and modifying the risk factors predisposing children to coronary heart disease.
Sepsis in children
Authors: Oda Keiko , Matsuo Yusaku , Nagai Kensuke , Tsumura Naoki , Sakata Yasutaka , Kato Hirohisa 
Published: March 2003

Abstract Background: Sepsis remains lethal to children. At our institution, we have noted that approximately 2% of all hospitalized patients have had sepsis. In the present study, we analyzed episodes of sepsis that occurred in our ward.
Methods
: Sepsis that occurred in our institution between January 1984 and December 1998 was reviewed and analyzed.
Results
: Three hundred and sixty‐six episodes of sepsis in 244 admitted patients were analyzed. Sepsis occurred in approximately 2% of all hospitalized patients. Forty‐three of 244 patients were under 1 year of age. Eighty‐seven percent (212/244) of cases had underlying diseases. Hematologic disorders or neoplasms were the most common underlying disease, comprising 55% of all patients (133/244). Two‐hundred and fifty‐one of 366 episodes of sepsis were acquired during hospitalization. We identified 409 causative agents. There were 25 polymicrobial infections (25/366; 7%). Gram‐positive bacteria comprised 68% of all organisms (280/409). Staphylococcus aureus was the most common organism, comprising 18% of causing agents (75/409). Sixty‐six organisms came from the insertion of a central venous catheter. Eighty‐one patients experienced recurrent episodes of sepsis. In terms of complications, respiratory distress was the most common complication (36 episodes) and there were 15 episodes of shock. Thirty‐seven patients died of sepsis. Sepsis caused by Gram‐negative bacteria showed significantly higher mortality than Gram‐positive bacteria (11/43 (26%) vs 15/146 (10%); P=0.053).
Conclusions
: In our institution, approximately 20% of septic patients were under 1 year of age and 90% had underlying diseases. The causative agents of sepsis affected the outcome.
Differences in transcutaneous bilirubin readings in Japanese term infants according to feeding method
Authors: Itoh Susumu , Kondo Masatoshi , Kusaka Takashi , Isobe Kenichi , Onishi Shoju 
Published: March 2003

Background
: Controversy has existed for many years over whether infant feeding methods are related to serum bilirubin concentrations during the first few days of life. Differences in initial jaundice patterns according to the feeding method until 72 h after birth have not been elucidated hitherto. The difference may become clear in Japanese neonates because jaundice shows a much higher peak bilirubin concentration and a later peak in Japanese neonates than in Caucasian neonates.
Methods
: In the present study, we investigated variations in the transcutaneous bilirubin reading (TcB) obtained within 72 h after birth among 177 breast‐fed and 494 formula‐fed healthy Japanese term neonates.
Results
: There was no difference between TcB in formula‐fed and breast‐fed infants until the first 30 h, after which time the rate of increase in TcB was lower in formula‐fed infants. Among breast‐fed neonates, a good linear regression between time after birth and TcB was maintained. Similarly, weight losses in breast‐fed infants at 24–48 h and 48–72 h after birth were greater than those in formula‐fed infants.
Conclusions
: The jaundice pattern in Japanese neonates from 30 to 72 h after birth according to the feeding method was different from that in Caucasian neonates.
A study of mismatch negativity in newborns
Authors: Tanaka Masaaki , Okubo Osami , Fuchigami Tatsuo , Harada Kensuke 
Published: March 2003

Abstract

Background
: Although newborns are presumed to have cognitive ability, studies on the objective cognitive ability of neonates are making little progress.
Methods
: We gave auditory and visual stimuli to newborns whose conceptional age ranged from 35 to 43 weeks and recorded the mismatch negativity (MMN) that is said to reflect the process by which stimuli are detected automatically. We compared the waveform and latency of the MMN.
Results
: The mismatch negativity waveform in newborns was similar to that of adults. The MMN latency tended to shorten with an advance in conceptional age and was especially shortened between 36 and 37 weeks of fetal life. In some newborns whose clinical course indicated a possibility of their having cognitive dysfunction, the MMN latency was prolonged.
Conclusions
: Newborns also have cognitive ability and MMN is useful for objectively evaluating the cognitive ability in newborns.
Balloon valvuloplasty for congenital heart disease: Immediate and long‐term results of multi‐institutional study
Authors: Echigo Shigeyuki 
Published: March 2003

Abstract

Background and Objectives
: Several studies have been reported in Japan. However, the reports consist of small series at individual institutions. We evaluated the immediate to long‐term results of balloon valvuloplasty (BVP) of congenital pulmonary and aortic stenosis at multi‐institutions in Japan.
Methods and Results
: Immediate and follow‐up data were obtained from eight institutions in Japan. In our series of 172 cases of pulmonary valuvuloplasty excluding critical pulmonary stenosis, the mean pressure gradient decreased immediately after BVP from 61~27 mmHg to 28~20 mmHg and the reduced gradient continued at follow‐up in most cases. The BVP for critical pulmonary stenosis could be accomplished in 35 of 39 patients. The mean right ventricular systolic pressure decreased from 102~29 mmHg to 62~23 mmHg. One of them required the surgical operation for perforation of the right ventricular outflow tract. In BVP for congenital aortic valvular stenosis of 77 cases excluding critical aortic stenosis, the mean pressure gradient decreased immediately after BVP from 68~24 mmHg to 34~23 mmHg. Thirty‐one cases (55%) were free from any interventions in long‐term follow‐up. The BVP for critical aortic stenosis was performed in 29 neonates. The overall mortality rate was 34% and 24% of the patients required repeat intervention. The remaining 42% was free from any interventions.
Conclusions
: Balloon valvuloplasty for congenital pulmonary valvular stenosis is a safe and effective procedure and the initial treatment of choice. In spite of an occasional major complication, BVP for critical pulmonary stenosis is effective in many infants. Balloon aortic valvuloplasty is palliative. However, this procedure has the efficacy in deferring the surgical intervention. Balloon valvuloplasty for neonatal critical aortic stenosis is a useful method to recover from serious conditions.