Three-dimensional printing (3 Dp) is being increasingly used in medical education. Although the use of such lifelike models is beneficial, well-powered, randomized studies supporting this statement ...are scarce. Two spinal fracture simulation models were generated by 3 Dp. Altogether, 120 medical students (54.2% females) were randomized into three teaching module groups two-dimensional computed tomography images (CT), 3D, or 3 Dp and asked to answer 10 key anatomical and 4 evaluative questions. Students in the 3 Dp or 3D group performed significantly better than those in the CT group, although males in the 3D group scored higher than females. Students in the 3 Dp group were the first to answer all questions, and there were no sex-related differences. Pleasure, assistance, effect, and confidence were more predominant in students in the 3 Dp group than in those in the 3D and CT groups. This randomized study revealed that the 3 Dp model markedly improved the identification of complex spinal fracture anatomy by medical students and was equally appreciated and comprehended by both sexes. Therefore, the lifelike fracture model made by 3 Dp technology should be used as a means of premedical education.
The purpose of this study was to evaluate the relationship of brain microvascular endothelial cell (BMECs) function and the exosomal miR-630 expression after subarachnoid hemorrhage (SAH). We ...evaluated the effects of blood cerebrospinal fluid (BCSF) on proliferation of BMECs by MTT at 0, 1, 3, 7 and 12 days and performed cell cycle analysis after BCSF treatment for 48 h. The expression of endothelial adhesion molecules (ICAM-1, VCAM-1 and ZO-1) were detected by qRT-PCR and immunofluorescent staining after BCSF treatment. NO produced by BMECs was also evaluated by Griess assay. The expression of exosomal miR-630 was analyzed by qRT-PCR in BCSF treated cell cultu normal cell culture medium andre medium. We further compared the exosomal miR-630 of clinical patients between aSAH and normal hydrocephalus. The adhesion molecules expression was further detected after co-incubation with exosomes transfected by miR-630 mimics. We found that BCSF significantly reduced the cell vitality in a time-dependent manner (p < 0.05) and the growth inhibition ratio reached 78.34 ± 9.22% on the 12th day. BCSF induced cell cycle arrest in G0/G1 phase in BMECs (p < 0.01). The expression of ICAM-1, VCAM-1, ZO-1 and the NO produced by BMECs were markedly reduced following incubation with BCSF. Then we demonstrated that the expression of exosomal miR-630 was markedly reduced in the BCSF treated BMECs and the same phenomenon occurred in aSAH patients compared with normal hydrocephalus. The expression of ICAM-1, VCAM-1 and ZO-1 were then increased in BMECs cocultured with exosomes transfected by miR-630 mimics. In conclusion, the low expression of exosomal miR-630 in CSF was closely related to endothelial function in BCSF endothelial cell injury model and clinical patients.
Background
Ribosomes responsible for transcription and translation of plastid-encoded proteins in chloroplasts are essential for chloroplast development and plant growth. Although most ribosomal ...proteins in plastids have been identified, the molecular mechanisms regulating chloroplast biogenesis remain to be investigated.
Results
Here, we identified albinic seedling mutant
albino seedling lethality 4
(
asl4
) caused by disruption of 30S ribosomal protein S1 that is targeted to the chloroplast. The mutant was defective in early chloroplast development and chlorophyll (Chl) biosynthesis. A 2855-bp deletion in the
ASL4
allele was verified as responsible for the mutant phenotype by complementation tests. Expression analysis revealed that the
ASL4
allele was highly expressed in leaf 4 sections and newly expanded leaves during early leaf development. Expression levels were increased by exposure to light following darkness. Some genes involved in chloroplast biogenesis were up-regulated and others down-regulated in
asl4
mutant tissues compared to wild type. Plastid-encoded plastid RNA polymerase (PEP)-dependent photosynthesis genes and nuclear-encoded phage-type RNA polymerase (NEP)-dependent housekeeping genes were separately down-regulated and up-regulated, suggesting that plastid transcription was impaired in the mutant. Transcriptome and western blot analyses showed that levels of most plastid-encoded genes and proteins were reduced in the mutant. The decreased contents of chloroplast rRNAs and ribosomal proteins indicated that chloroplast ribosome biogenesis was impaired in the
asl4
mutant.
Conclusions
Rice
ASL4
encodes 30S ribosomal protein S1, which is targeted to the chloroplast.
ASL4
is essential for chloroplast ribosome biogenesis and early chloroplast development. These data will facilitate efforts to further elucidate the molecular mechanism of chloroplast biogenesis.
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