It is known that plasma serine and threonine concentrations are elevated in rats chronically fed an essential amino acid deficient diet, but the underlying mechanisms including related gene ...expressions or serine and threonine concentrations in liver remained to be elucidated. We fed rats lysine or valine deficient diet for 4 weeks and examined the mRNA expressions of serine synthesising (3-phosphoglycerate dehydrogenase, PHGDH) and serine/threonine degrading enzymes (serine dehydratase, SDS) in the liver. Dietary deficiency induced marked elevation of hepatic serine and threonine levels associated with enhancement of PHGDH mRNA expression and repression of SDS mRNA expression. Increases in plasma serine and threonine levels due to essential amino acid deficiency in diet were caused by marked increases in hepatic serine and threonine levels. Proteolytic responses to the amino acid deficiency may be lessened by storing amino radicals as serine and inducing anorexia through elevation of threonine.
When growth hormone binds to its receptor, which belongs to the cytokine receptor superfamily, it activates the Janus kinase Jak2 which has tyrosine-kinase activity and initiates an activation of ...several key intracellular proteins (for example, mitogen-activated protein (MAP) kinases) that eventually execute the biological actions induced by growth hormone, including the expression of particular genes. In contrast to receptors that themselves have tyrosine kinase activity, the signalling pathways leading to MAP kinase activation, that are triggered by growth hormone are poorly understood, but appear to be mediated by the proteins Grb2 and Shc. We now show that growth hormone stimulates tyrosine phosphorylation of the receptor for epidermal growth factor (EGFR) and its association with Grb2 and at the same time stimulates MAP kinase activity in liver, an important target tissue of growth hormone. Expression of EGFR and its mutants revealed that growth-hormone-induced activation of MAP kinase and expression of the transcription factor c-fos requires phosphorylation of tyrosines on EGFR, but not its own intrinsic tyrosine-kinase activity. Moreover, tyrosine at residue 1,068 of the EGFR is proposed to be one of the principal phosphorylation sites and Grb2-binding sites stimulated by growth hormone via Jak2. Our results indicate that the role of EGFR in signalling by growth hormone is to be phosphorylated by Jak2, thereby providing docking sites for Grb2 and activating MAP kinases and gene expression, independently of the intrinsic tyrosine kinase activity of EGFR. This may represent a novel cross-talk pathway between the cytokine receptor superfamily and growth factor receptor.
Purpose
Pathological Internet use has been predominantly studied in junior high/middle school-aged or older children; data from elementary/primary school-aged children, however, are scarce. The ...current study aimed to examine the prevalence of problematic Internet use, including pathological and maladaptive Internet use, in elementary and junior high school-aged children and the relationships between problematic Internet use and mental health problems and health-related quality of life.
Methods
The survey was conducted among children who attend national and public elementary and junior high schools in a medium-sized city in Japan; data were received from 3845 elementary school-aged and 4364 junior high school-aged children.
Results
Based on the Young’s Diagnostic Questionnaire score, the prevalence of pathological and maladaptive Internet use was 3.6% and 9.4% and 7.1% and 15.8% in elementary and junior high school-aged children, respectively. The prevalence of problematic Internet use, including pathological and maladaptive Internet use, consistently increased from the 4th grade to the 8th grade. In addition, the prevalence sharply increased between the 7th grade and the 8th grade. Our study revealed that children with pathological and maladaptive Internet use exhibited more severe depression and decreased health-related quality of life than those with adaptive Internet use.
Conclusions
Our results demonstrated that pathological Internet use is not uncommon even in elementary school-aged children and that those with pathological and maladaptive Internet use have severe mental health problems and decreased health-related quality of life, supporting the importance of providing these children with educational and preventive interventions against problematic Internet use and associated risk factors.
The changes in the concentrations of plasma amino acids do not always follow the flow-based metabolic pathway network. We have previously shown that there is a control-based network structure among ...plasma amino acids besides the metabolic pathway map. Based on this network structure, in this study, we performed dynamic analysis using time-course data of the plasma samples of rats fed single essential amino acid deficient diet. Using S-system model (conceptual mathematical model represented by power-law formalism), we inferred the dynamic network structure which reproduces the actual time-courses within the error allowance of 13.17%. By performing sensitivity analysis, three of the most dominant relations in this network were selected; the control paths from leucine to valine, from methionine to threonine, and from leucine to isoleucine. This result is in good agreement with the biological knowledge regarding branched-chain amino acids, and suggests the biological importance of the effect from methionine to threonine.
Thesis: M.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1979
Bibliography: leaves 38-39.
by Michio Takahashi.
M.S.
M.S. Massachusetts Institute of Technology, ...Department of Mechanical Engineering
Previous studies have performed cross-cultural comparisons of differences in childhood sleep problems between Asian and Western countries. However, whether such differences can be observed among ...Asian countries remains unclear. The present study aimed to investigate differences in the pattern of sleep problems between Japanese and Chinese preschoolers.
Data were collected from one city in Japan and 10 cities in China. The present study recruited 438 Japanese and 1020 Chinese preschoolers aged four and five years. Sleep problems and patterns were assessed on the basis of parental reports using the Children's Sleep Habits Questionnaire (CSHQ).
Analysis of covariance revealed no significant difference in total CSHQ scores between Japanese and Chinese preschoolers, thus indicating that the total severity of sleep problems did not differ between the groups. Japanese preschoolers exhibited higher scores on the bedtime resistance subscale of the CSHQ than Chinese preschoolers. Conversely, Chinese preschoolers exhibited higher subscale scores for night wakings and sleep-disordered breathing. In addition, Japanese preschoolers exhibited earlier bedtimes and wake times and shorter total sleep times than Chinese preschoolers.
Our findings indicate that the patterns of sleep problems in preschoolers differ between Japan and China and that such differences may be due to differences in cosleeping practices, bedtime routines, and/or environmental conditions. Thus, investigators studying sleep in preschoolers should consider regional differences in the pattern of sleep problems, even among Asian countries.
•We compared sleep problems between Japanese and Chinese preschoolers.•The total severity of sleep problems were not different between the two countries.•Bedtime resistance was more severe in Japanese children.•Chinese children had more severe nighttime awakenings and sleep-disordered breathing.
Although research has demonstrated associations between motor coordination difficulties and psychological problems in school-age children, including emotional and behavioral problems, longitudinal ...changes in these problems in children with motor coordination difficulties are not fully understood.
The current study aimed to identify patterns in the trajectory of emotional and behavioral problems in school-age children with motor coordination difficulties, and to elucidate the effect of co-existing neurodevelopmental traits on the occurrence and course of these problems.
Using the Developmental Coordination Disorder Questionnaire, 773 children were defined as cases with motor coordination difficulties and followed for 4 years, from 6 to 10 years of age. Emotional and behavioral problems were assessed using the Strengths and Difficulties Questionnaire completed by children’s parents or guardians.
We identified four trajectory patterns of emotional and behavioral problems. Children with higher autism spectrum disorder and attention deficit hyperactivity disorder traits were more likely to be assigned to poor prognostic trajectory patterns.
Our findings emphasize the importance of assessing emotional and behavioral problems and co-existing neurodevelopmental traits in children with motor coordination difficulties in early elementary school.
•We examined a community sample with motor coordination difficulties attending public elementary school in a city in Japan.•We used latent class growth analysis to examine data from prospective school surveys collected over 4 years.•Four trajectory patterns of emotional and behavioral problems were identified.•6 % of children showed a gradual increase in problems over the 4 years from 6 to 10 years of age.
In human volunteers who have been continuously experiencing unsatisfactory sleep, effects of glycine ingestion (3 g) before bedtime on subjective sleep quality were investigated, and changes in ...polysomnography (PSG) during sleep were analyzed. Effects on daytime sleepiness and daytime cognitive function were also evaluated. Glycine improved subjective sleep quality and sleep efficacy (sleep time/in‐bed time), and shortened PSG latency both to sleep onset and to slow wave sleep without changes in the sleep architecture. Glycine lessened daytime sleepiness and improved performance of memory recognition tasks. Thus, a bolus ingestion of glycine before bedtime seems to produce subjective and objective improvement of the sleep quality in a different way than traditional hypnotic drugs such as benzodiazepines.
Safflower seed extract (SSE) contains characteristic polyphenols and serotonin derivatives (N-( p-coumaroyl) serotonin and N-feruloylserotonin), which are reported to inhibit oxidation of low-density ...lipoprotein (LDL), formation of atherosclerotic plaques, and improve arterial stiffness as assessed by pulse wave analysis in animal models. The effects of long-term supplementation with SSE on arterial stiffness in human subjects were evaluated. This doubleblind, placebo-controlled study was conducted in 77 males (35-65 years) and 15 postmenopausal females (55-65 years) with high-normal blood pressure or mild hypertension who were not undergoing treatment. Subjects received SSE (70 mg/day as serotonin derivatives) or placebo for 12 weeks, and pulse wave measurements, ie, second derivative of photoplethysmogram (SDPTG), augmentation index, and brachial-ankle pulse wave velocity (baPWV) were conducted at baseline, and at weeks 4, 8, and 12. Vascular age estimated by SDPTG aging index improved in the SSE-supplemented group when compared with the placebo group at four (P = 0.0368) and 12 weeks (P = 0.0927). The trend of augmentation index reduction (P = 0.072 versus baseline) was observed in the SSE-supplemented group, but reduction of baPWV by SSE supplementation was not observed. The SSE-supplemented group also showed a trend towards a lower malondialdehyde-modified-LDL autoantibody titer at 12 weeks from baseline. These results suggest long-term ingestion of SSE in humans could help to improve arterial stiffness.
Accumulating evidence implicates interleukin-8 (IL-8) as an essential mediator in neutrophil-mediated acute inflammation. Neutrophils have also been shown to have a crucial role in the pathogenesis ...of acute gouty arthritis. Thus, we investigate the pathophysiological role of IL-8 in an experimental model of acute gout, monosodium urate (MSU) crystal-induced arthritis in rabbits. The injection of MSU crystals into knee joints caused a marked swelling of joints. Concomitantly, the infiltration ofleukocytes, mostly neutrophils, was observed in synovial membrane and synovial fluids. The injection of MSU crystals also induced an elevation in synovial fluid IL-8 levels preceding neutrophil infiltration into synovial fluids, without an accompanying increase in plasma IL-8 levels. Immunoreactive IL-8 protein was detected in synovial lining cells at 12-24 h after the injection. IL-8 protein was also observed in infiltrated leukocytes in synovium as early as 3-24 h after the injection. Finally, the intraarticular injection of a neutralizing anti-IL-8 antibody significantly attenuated the crystal-induced joint swelling that occurred at 12 h, and neutrophil infiltration into arthritic joints at 12 and 24 h after the induction. These results provide evidence on the pathogenic roles of locally produced IL-8 in MSU crystal-induced gouty arthritis.
PDF
