Identification of rare variants causing urea cycle disorders: A clinical, genetic, and biophysical study.

Urea cycle disorders (UCDs) are a group of rare metabolic conditions characterized by hyperammonemia and a broad spectrum of phenotypic severity. They are caused by the congenital deficiency in the eight biomolecules involved in urea cycle. In the present study, five cases of UCD were recruited and submitted to a series of clinical, biochemical, and genetic analysis with a combination of high throughput techniques. Moreover, in silico analysis was conducted on the identified missense genetic variants. Various clinical and biochemical indications (including profiles of amino acids and urinary orotic acids) of UCD were manifested by the five probands. Sequence analysis revealed nine diagnostic variants, including three novel ones, which caused Argininosuccinic aciduria (ASA) in one case, Carbamoyl phosphate synthetase 1deficiency (CPS1D) in two cases, Ornithine transcarbamylase deficiency (OTCD) in one case, and Citrin deficiency in 1case. Results of in silico biophysical analysis strongly suggested the pathogenicity of each the five missense variants and provided insight into their intramolecular impacts. In conclusion, this study expanded the genetic variation spectrum of UCD, gave solid evidence for counselling to the affected families, and should facilitate the functional study on the proteins in urea cycle.

[Clinical and imaging features of premature infants with different degrees of bronchopulmonary dysplasia].

OBJECTIVE: To study the clinical and imaging features of premature infants with different degrees of bronchopulmonary dysplasia (BPD). METHODS: A prospective study was performed on the clinical data of 59 premature infants (gestational age <32 weeks) with BPD. Among the 59 premature infants, 37 cases had mild BPD and the other 22 cases had moderate to severe BPD. The clinical and imaging data were compared between these premature infants with different degrees of BPD. RESULTS: The durations of mechanical ventilation, oxygen therapy, antibiotic therapy, parenteral nutrition, and hospitalization in the moderate to severe group were significantly longer than those in the mild group (P<0.05). The incidence of nosocomial infection and number of times of red blood cell transfusion in the moderate to severe group were significantly higher than that in the mild group. The rates of X-ray changes, including grade I respiratory distress syndrome (1 day after birth) and hypolucency of lungs (4-10 days and ≥ 28 days after birth) were significantly higher in the mild group than in the moderate to severe group. The rates of X-ray changes in classical BPD stage III (4-10 days after birth) and IV (≥ 28 days after birth) were significantly higher in the moderate to severe group than in the mild group. CONCLUSIONS: The durations of mechanical ventilation, oxygen therapy, and antibiotic therapy and the incidence of nosocomial infection are correlated with the severity of BPD. The premature infants with severer BPD need a longer duration of parenteral nutrition and more times of red blood cell transfusion and have more typical imaging changes of BPD. Imaging examination has a predictive value for the severity of BPD.

[Relationship between the growth rate of corpus callosum and neuromotor delay in premature infants].

OBJECTIVE: To study the relationship between the growth rate of the corpus callosum and neurological motor development in premature infants. METHODS: Fifty infants whose gestational ages were less than 34 weeks and who were admitted to the neonatal intensive care unit from March 2007 to August 2007 were enrolled. From 0 to 6 weeks of postnatal age, the sagittal midline cranial sonography via anterior fontanel was performed, once weekly. The length and the morphology of the corpus callosum were measured. The 52-neuromotor examinations were performed at 3 months of corrected gestational age. RESULTS: The mean length of the corpus callosum was 39.16 mm at birth. The mean growth rate of the corpus callosum during the first 6 weeks of life was 1.05 mm/week. Fourteen infants showed abnormal neuromotor development and 36 had normal-neuromotor function at 3 months of corrected gestational age. A decreased growth rate of the corpus callosum was observed in the abnormal nervimotion group between 2 and 3 weeks (0.68 mm/week vs 1.17 mm/week) and between 4 and 5 weeks (0.86 mm/week vs 1.12 mm/week) after birth compared with that in normal nervimotion group (p<0.05). The total growth rate of the corpus callosum from 2 to 6 weeks after birth in the abnormal nervimotion group was also lower than that in the normal nervimotion group (0.91 mm/week vs 1.15 mm/week; p<0.01). CONCLUSIONS: A neuromotor delay at 3 months of corrected gestational age may be associated with the decreased growth rate of the corpus callosum between 2 and 6 weeks of life in premature infants.

A quick response fluorescent probe based on coumarin and quinone for glutathione and its application in living cells.

We have designed and synthesized a simple but effective fluorescent probe for sensing glutathione (GSH) by PET process based on coumarin and quinone, which worked as fluorophore and reaction site, respectively. The probe could discriminate GSH from cysteine and homocysteine within 1 min in PBS-buffered solution. The sensing mechanism was confirmed by density functional theory (DFT), viscosity test, fluorescence spectrum analysis and HRMS, respectively. The probe has a low limit of detection (0.1 µM) and finally been used in cell imaging successfully.

A colorimetric, ratiometric and water-soluble fluorescent probe for simultaneously sensing glutathione and cysteine/homocysteine.

A chlorinated coumarin-aldehyde was developed as a colorimetric and ratiometric fluorescent probe for distinguishing glutathione (GSH), cystenine (Cys) and homocysteine (Hcy). The GSH-induced substitution-cyclization and Cys/Hcy-induced substitution-rearrangement cascades lead to the corresponding thiol-coumarin-iminium cation and amino-coumarin-aldehyde with distinct photophysical properties. The probe can be used to simultaneously detect GSH and Cys/Hcy by visual determination based on distinct different colors - red and pale-yellow in PBS buffer solution by two reaction sites. From the linear relationship of fluorescence intensity and biothiols concentrations, it was determined that the limits of detection for GSH, Hcy and Cys are 0.08, 0.09 and 0.18 µM, respectively. Furthermore, the probe was successfully used in living cell imaging with low cell toxicity.

An effective colorimetric and ratiometric fluorescent probe for bisulfite in aqueous solution.

We have developed the first two-photon colorimetric and ratiometric fluorescent probe, BICO, for the detection of bisulfite (HSO3(-)) in aqueous solution. The probe contains coumarin and benzimidazole moieties and can detect HSO3(-) based on the Michael addition reaction with a limit of detection 5.3 × 10(-8) M in phosphate-buffered saline solution. The probe was used to detect bisulfite in tap water, sugar and dry white wine. Moreover, test strips were made and used easily. We successfully applied the probe to image living cells, using one-photon fluorescence imaging. BICO overcomes the limitations in sensitivity of previously reported probes and the solvation effect of bisulfite, which demonstrates its excellent value in practical application.