BACKGROUND The mitochondrial respiratory chain defects have become the most common cause of neurometabolic disorders in children and adults,which can occur at any time in life,often associated with neurological dysfun...BACKGROUND The mitochondrial respiratory chain defects have become the most common cause of neurometabolic disorders in children and adults,which can occur at any time in life,often associated with neurological dysfunction,and lead to chronic disability and premature death.Approximately one-third of patients with mitochondrial disease have biochemical defects involving multiple respiratory chain complexes,suggesting defects in protein synthesis within the mitochondria.We here report a child with VARS2 gene mutations causing mitochondrial disease.CASE SUMMARY A girl,aged 3 years and 4 mo,had been unable to sit and crawl alone since birth,with obvious seizures and microcephaly.Brain magnetic resonance imaging showed symmetrical,flaky,long T1-weighted and low T2-weighted signals in the posterior part of the bilateral putamen with a high signal shadow.T2 fluidattenuated inversion recovery imaging showed a slightly high signal and diffusion-weighted imaging showed an obvious high signal.Whole-exome gene sequencing revealed a compound heterozygous mutation in the VARS2 gene,c.1163(exon11)C>T and c.1940(exon20)C>T,which was derived from the parents.The child was diagnosed with combined oxidative phosphorylation deficiency type 20.CONCLUSION In this patient,mitochondrial disorders including Leigh syndrome and MELAS syndrome(mitochondrial myopathy,encephalopathy,lactic acidosis,and stroke-like episodes)were ruled out,and combined oxidative phosphorylation deficiency type 20 was diagnosed,expanding the phenotypic spectrum of the disease.展开更多
Nitrogen is essential for plant growth and development,with the ratio of ammonium(NH_(4)^(+))to nitrate(NO_(3)^(-))critically influencing physiological efficiency.This study investigated the effects of different NH_(4...Nitrogen is essential for plant growth and development,with the ratio of ammonium(NH_(4)^(+))to nitrate(NO_(3)^(-))critically influencing physiological efficiency.This study investigated the effects of different NH_(4)^(+)-N/NO_(3)^(-)-N mass ratios(0︰1,3︰7,1︰1,7︰3,1︰0)and a no-nitrogen control on Zanthoxylum planispinum var.dintanensis seedlings,using NH_(4)Cl and NaNO_(3) as nitrogen sources.Key results revealed that a 3︰7 NH_(4)^(+)︰NO_(3)^(-)ratio(T2)significantly enhanced stomatal conductance(G_(s)),amino acid content,root tip number,and the photochemical quenching parameters q_(P),q_(L),ETR,and F_(v)/F_(m).This treatment also maximized ground diameter increment,chlorophyll content,intercellular CO_(2)concentration(C_(i)),transpiration rate(T_(r)),ribulose-1,5-bisphosphate carboxylase(Rubisco)activity,nitrate reductase(NR)activity,and soluble protein content.Conversely,a 7︰3 ratio(T4)yielded the highest net photosynthetic rate(Pn)and fructose-1,6-bisphosphate aldolase(FBA)activity.Overall,the T4 treatment exhibited the second most effective promotion of Z.planispinum var.dintanensis seedling growth and development,after T2.In summary,mixed NH_(4)^(+)-N/NO_(3)^(-)-N nutrition markedly enhances seedling performance,with the 3︰7 ratio optimal for growth,photosynthesis,and nitrogen assimilation.Sole nitrogen sources,particularly pure NH_(4)^(+)-N,exert inhibitory effects.展开更多
文摘BACKGROUND The mitochondrial respiratory chain defects have become the most common cause of neurometabolic disorders in children and adults,which can occur at any time in life,often associated with neurological dysfunction,and lead to chronic disability and premature death.Approximately one-third of patients with mitochondrial disease have biochemical defects involving multiple respiratory chain complexes,suggesting defects in protein synthesis within the mitochondria.We here report a child with VARS2 gene mutations causing mitochondrial disease.CASE SUMMARY A girl,aged 3 years and 4 mo,had been unable to sit and crawl alone since birth,with obvious seizures and microcephaly.Brain magnetic resonance imaging showed symmetrical,flaky,long T1-weighted and low T2-weighted signals in the posterior part of the bilateral putamen with a high signal shadow.T2 fluidattenuated inversion recovery imaging showed a slightly high signal and diffusion-weighted imaging showed an obvious high signal.Whole-exome gene sequencing revealed a compound heterozygous mutation in the VARS2 gene,c.1163(exon11)C>T and c.1940(exon20)C>T,which was derived from the parents.The child was diagnosed with combined oxidative phosphorylation deficiency type 20.CONCLUSION In this patient,mitochondrial disorders including Leigh syndrome and MELAS syndrome(mitochondrial myopathy,encephalopathy,lactic acidosis,and stroke-like episodes)were ruled out,and combined oxidative phosphorylation deficiency type 20 was diagnosed,expanding the phenotypic spectrum of the disease.
文摘Nitrogen is essential for plant growth and development,with the ratio of ammonium(NH_(4)^(+))to nitrate(NO_(3)^(-))critically influencing physiological efficiency.This study investigated the effects of different NH_(4)^(+)-N/NO_(3)^(-)-N mass ratios(0︰1,3︰7,1︰1,7︰3,1︰0)and a no-nitrogen control on Zanthoxylum planispinum var.dintanensis seedlings,using NH_(4)Cl and NaNO_(3) as nitrogen sources.Key results revealed that a 3︰7 NH_(4)^(+)︰NO_(3)^(-)ratio(T2)significantly enhanced stomatal conductance(G_(s)),amino acid content,root tip number,and the photochemical quenching parameters q_(P),q_(L),ETR,and F_(v)/F_(m).This treatment also maximized ground diameter increment,chlorophyll content,intercellular CO_(2)concentration(C_(i)),transpiration rate(T_(r)),ribulose-1,5-bisphosphate carboxylase(Rubisco)activity,nitrate reductase(NR)activity,and soluble protein content.Conversely,a 7︰3 ratio(T4)yielded the highest net photosynthetic rate(Pn)and fructose-1,6-bisphosphate aldolase(FBA)activity.Overall,the T4 treatment exhibited the second most effective promotion of Z.planispinum var.dintanensis seedling growth and development,after T2.In summary,mixed NH_(4)^(+)-N/NO_(3)^(-)-N nutrition markedly enhances seedling performance,with the 3︰7 ratio optimal for growth,photosynthesis,and nitrogen assimilation.Sole nitrogen sources,particularly pure NH_(4)^(+)-N,exert inhibitory effects.
