The Effect of tRNA[Ser]Sec Isopentenylation on Selenoprotein Expression

Transfer RNA[Ser]Sec carries multiple post-transcriptional modifications. The A37G mutation in tRNA[Ser]Sec abrogates isopentenylation of base 37 and has a profound effect on selenoprotein expression in mice. Patients with a homozygous pathogenic p.R323Q variant in tRNA-isopentenyl-transferase (TRIT1) show a severe neurological disorder, and hence we wondered whether selenoprotein expression was impaired. Patient fibroblasts with the homozygous p.R323Q variant did not show a general decrease in selenoprotein expression. However, recombinant human TRIT1R323Q had significantly diminished activities towards several tRNA substrates in vitro. We thus engineered mice conditionally deficient in Trit1 in hepatocytes and neurons. Mass-spectrometry revealed that hypermodification of U34 to mcm5Um occurs independently of isopentenylation of A37 in tRNA[Ser]Sec. Western blotting and 75Se metabolic labeling showed only moderate effects on selenoprotein levels and 75Se incorporation. A detailed analysis of Trit1-deficient liver using ribosomal profiling demonstrated that UGA/Sec re-coding was moderately affected in Selenop, Txnrd1, and Sephs2, but not in Gpx1. 2′O-methylation of U34 in tRNA[Ser]Sec depends on FTSJ1, but does not affect UGA/Sec re-coding in selenoprotein translation. Taken together, our results show that a lack of isopentenylation of tRNA[Ser]Sec affects UGA/Sec read-through but differs from a A37G mutation.

SURVEY ON THE USE OF CARBAPENEM ANTIBIOTICS AT CAN THO CHILDREN’S HOSPITAL

Objective: To survey the use of carbapenem antibiotics at Can Tho Children’s Hospital. Objects and methods: Retrospective-descriptive study on 140 medical records of patients being treated at departments of Can Tho Children’s Hospital during the period from June 1st, 2020 to December 31st, 2020. Results: 26.43% of carbapenems were indicated empirically initiate, 73.57% of carbapenem was indicated in alternative regimens as the presence of microbiological results or worsened or impaired patient status. Carbapenem was mainly used in combination regimens. The proportion of the combination in the initiation regimen was 100%. In which, the proportion of combination regimen between carbapenem and an antibiotic (or vancomycin or gentamicin) was mainly. The rate of combination of three antibiotics was 18.9%. In the replacement regimen, the proportion of combination regimen was 79.6%. Of these, 57.3% of the carbapenem was combined with another antibiotic, most of which was combined with vancomycin. Combination regimen of three or four antibiotics accounted for a low percentage. Conclusion: 26.43% of carbapenem was indicated empirically initiate, 73.57% of carbapenem was indicated in an alternative regimen in the presence of microbiological results or worsened or impaired patient status. Carbapenem was mainly used in combination regimens.

Design of an Obstacle and Location-Based Detector with Microcontroller System

Out of seven billion of the world’s population, two billion and two million that amounts to 31.43% have visual impairment or blindness according to the World Health Organization (WHO) statistics report. Hence, the need to develop a wearable device with reduced size, efficient power usage, and for more comfortability of the visually impaired or blind people. This work aims at designing an obstacle detection system using an ultrasonic sensor interfaced with an Arduino board to track location, alert patient, and send location messages of visually impaired patient to guardians as a feedback mechanism using a GPRS and GSM module. The C programming language was used as the instruction code to interface Arduino device to carry out given tasks. At the design level, the circuit was first tested on Proteus software for simulation purposes before its hardware implementation. The results obtained from the test show the variation of distance as the patient approaches the obstacle, and messages received when a fix was obtained. This design concept would help reduce danger across the way of those with sight defects and allow them to go to familiar places without any aid smoothly.