Liver transplantation for late-onset ornithine transcarbamylase deficiency:A case report

BACKGROUND Ornithine transcarbamylase deficiency(OTCD)is an X-linked inherited disorder and characterized by marked elevation of blood ammonia.The goal of treatment is to minimize the neurological damage caused by hyperammonemia.OTCD can be cured by liver transplantation(LT).Post-transplant patients can discontinue anti-hyperammonemia agents and consume a regular diet without the risk of developing hyperammonemia.The neurological damage caused by hyperammonemia is almost irreversible.CASE SUMMARY An 11.7-year-old boy presented with headache,vomiting,and altered consciousness.The patient was diagnosed with late-onset OTCD.After nitrogen scavenging treatment and a protein-free diet,ammonia levels were reduced to normal on the third day of admission.Nevertheless,the patient remained in a moderate coma.After discussion,LT was performed.Following LT,the patient’s blood ammonia and biochemical indicators stabilized in the normal range,he regained consciousness,and his nervous system function significantly recovered.Two months after LT,blood amino acids and urine organic acids were normal,and brain magnetic resonance imaging showed a decrease in subcortical lesions.CONCLUSION LT can significantly improve partial neurological impairment caused by late-onset OTCD hyperammonemic encephalopathy,and LT can be actively considered when early drug therapy is ineffective.

Structural Properties of Ions and Polyelectrolytes in Aqueous Solutions under External Electric Fields:The Sign Effect

We utilize molecular dynamics simulations to investigate the microstructures of ions and polyelectrolytes in aqueous solutions under external electric fields.By focusing on the multi-body interactions between ionic components and H_(2)O molecules,as well as their responses to the external electric fields,we clarify several nontrivial molecular features of the ionic and polyelectrolyte solutions,such as the solvations of cations and anions,clustering of the ions,and dispersions/aggregations of polyelectrolyte chains,as well as the corresponding responses of H_(2)O molecules in these contexts.Our simulations illustrate the variations in structures of ionic solutions caused by reversing the charge sign of the ions,and elucidate the disparity in structures between anionic and cationic polyelectrolyte solutions in the presence of the external electric fields.This work clarifies the mechanism for the alternations in complex multi-body interactions in aqueous solutions caused by the application electric field,which can contribute to the fundamental understanding of the physical and chemical natures of ion-containing and charged polymeric systems.

Pore-Directed Solid-State Selective Photoinduced E–Z Isomerization and Dimerization within Metal–Organic Frameworks

Design and construction of suitable pore microenvironments for selective catalytic reactions of small guest molecules is a major goal for chemists.Herein,we report control of competitive E–Z photoisomerization and photodimerization within porous metal–organic frameworks(MOFs)by fine-tuning the pore microenvironments using different dicarboxylate linkers.MOFs with small pores((E)-X_(MOF_(1))and(E)-X_(MOF_(1))′)favor the photoinduced E–Z isomerization of one encapsulated diaryl alkene substrate while those with large pores(((E)-X)_(2MOF_(2)))prefer the photodimerization of two encapsulated alkene substrates.Both reactions show broad functional group compatibility and proceed stereospecifically in good yields under mild conditions.High local concentration of diaryl alkene ligands and their preorientation within pores facilitate stereoselective dimerization.This pore engineering strategy is applicable to control and create pore microenvironemnts for other photoinduced organic reactions within porous MOFs.