Objective To investigate the effect of 620 nm red light on chondrogenic differentiation in rat precartilaginous stem cells (PSCs). Methods Rats' PSCs were isolated and purified using magnetically activated cell sorting and cultured in vitro.The PSCs were exposed once to 620 nm wavelength red light from a light-emitting diode (LED) with an irradiation energy of 0.5 J/cm2,1 J/cm2,2 J/cm2 or 4 J/cm2.Any effect was confirmed by Alcian blue staining,immunohistochemistry and observing histomorphological changes under a light microscope,as well as detection using a reverse transcription polymerase chain reaction (RT-PCR). Results After being induced for 14 d,the PSCs exhibited polygonal and round shapes. Alcian blue and type Ⅱ collagen immunohistoehemistry staining showed positive results,but the control group had no significant change.RT-PCR showed that the mRNA expression of Sox9 and type Ⅱ collagen increased significantly compared with the control group. Conclusion Low energy 620 nm red light can enhance chondrogenic differentiation in PSCs significantly.
Key words:
Chondrocytes ; Cell differentiation ; Precartilaginous stem cells; Red light
Developing neurons have greater capacity in experience-dependent plasticity than adult neurons but the molecular mechanism is not well understood. Here we report a developmentally regulated long-term synaptic plasticity through actin-dependent activation of presynaptic silent synapses in cultured hippocampal neurons. Live FM 1-43 imaging and retrospective immunocytochemistry revealed that many presynaptic boutons in immature neurons are functionally silent at resting conditions, but can be converted into active ones after repetitive neuronal stimulation. The activation of presynaptic silent synapses is dependent on L-type calcium channels and protein kinase A (PKA)/PKC signaling pathways. Moreover, blocking actin polymerization with latrunculin A and cytochalasin B abolishes long-term increase of presynaptic functional boutons induced by repetitive stimulation, whereas actin polymerizer jasplakinolide increases the number of active boutons in immature neurons. In mature neurons, however, presynaptic boutons are mostly functional and repetitive stimulation did not induce additional enhancement. Quantitative immunostaining with phalloidin revealed a significant increase in axonal F-actin level after repetitive stimulation in immature but not mature neurons. These results suggest that actin-dependent activation of presynaptic silent synapses contributes significantly to the long-term synaptic plasticity during neuronal development.
Abstract Transcription factor-mediated cell conversion has been reported in the central nervous system (CNS) of both rodents and non-human primates (NHPs). In particular, glia-to-neuron (GtN) conversion has been achieved in the brains and spinal cords of animal models of neurological disorders for neural regeneration and repair. However, whether GtN conversion can ultimately be used for human brain repair in patients is still unknown. To investigate the applicability of GtN conversion technology in the human brain, we established a long-term ex vivo culture system using human brain tissue that was surgically removed from epileptic patients to directly test GtN conversion. We demonstrate that both neural transcription factors NeuroD1 and Ascl1 can convert human glial cells into neurons. Importantly, both immunostaining and electrophysiological recordings revealed that the glia-converted neurons showed immature properties during the initial 1–2 weeks of conversion, and then acquired more mature neuronal properties after 3–4 weeks of conversion. These ex vivo conversion studies in human brain tissue pave the way toward future clinical trials using a transcription factor-based glia-to-neuron conversion approach to treat neurological disorders.
The skinfold thicknesses of calf,suprailiac,subscapular,triceps,biceps and facial on 422 rural adults(222 males and 200 females) of Han were investigated in Qionglai of Sichuan province.The results show that the skinfold thickness of rural adults from Qionglai is obviously thicker than that of Derung,Uzbek,Russ and Han(Shandong rural).As a whole,the skinfold thickness of female is thicker than male.The curves of male skinfold thickness inconspicuously fluctuate with the increasing age.The skinfold thicknesses of females show most significant differences among different age groups.The age that the peak maximum of skinfold thickness appears in different parts of body has relations with body growth and hormone levels.
Acidovorax citrulli is the causal agent of bacterial fruit blotch, a serious threat to cucurbit crop production worldwide. Based on genetic and phenotypic properties, A. citrulli strains are divided into two major groups: group I strains have been generally isolated from melon and other non-watermelon cucurbits, while group II strains are closely associated with watermelon. In a previous study, we reported the genome of the group I model strain, M6. At that time, the M6 genome was sequenced by MiSeq Illumina technology, with reads assembled into 139 contigs. Here we report the assembly of the M6 genome following sequencing with PacBio technology. This approach not only allowed full assembly of the M6 genome, but it also revealed the occurrence of a ~53 kb plasmid. The M6 plasmid, named pACM6, was further confirmed by plasmid extraction, Southern-blot analysis of restricted fragments and obtention of M6-derivative cured strains. pACM6 occurs at low copy numbers (average of ~4.1 1.3 chromosome equivalents) in A. citrulli M6 and contains 63 open reading frames, most of which (55.6%) encoding hypothetical proteins. The plasmid contains several genes encoding type IV secretion components, and typical plasmid-borne genes involved in plasmid maintenance, replication and transfer. The plasmid also carries an operon encoding homologs of a Fic-VbhA toxin-antitoxin (TA) module. Transcriptome data from A. citrulli M6 revealed that, under the tested conditions, the genes encoding the components of this TA system are among the highest expressed genes in pACM6. Whether this TA module plays a role in pACM6 maintenance is still to be determined. Leaf infiltration and seed transmission assays revealed that, under tested conditions, the loss of pACM6 did not affect the virulence of A. citrulli M6. We also show that pACM6 or similar plasmids are present in several group I strains, but absent in all tested group II strains of A. citrulli.
Objectives: As of June 1, 2020, Coronavirus disease 2019 (COVID-19) has caused a global pandemic and resulted in over 370,000 deaths worldwide. Early identification of COVID-19 patients who need to be admitted to intensive care unit (ICU) helps improve the outcomes. We aim to investigate whether absolute eosinophil count (AEC) can predict ICU transfer among elderly COVID-19 patients from general isolated wards. Methods: A retrospective study of 94 elderly patients older than 60 years of age with COVID-19 was conducted. We compared the basic clinical characteristics and levels of inflammation markers on admission to general isolated wards and the needs for ICU transfer between the eosinopenia (AEC on admission <20 cells/µL) and non-eosinopenia (AEC ≥20 cells/µL) groups. Results: There was a significantly higher ICU transfer rate in the eosinopenia group than the non-eosinopenia group (51% vs. 9%, P <0.001). Multivariate analysis revealed that eosinopenia was associated with an increased risk of ICU transfer in elderly COVID-19 patients (adjusted OR 6.12 [95% CI, 1.23-30.33], P = 0.027]) after adjustment of age, lymphocyte count, neutrophil count, C-reactive protein (CRP) and ferritin levels. The eosinopenia group had higher levels of CRP, ferritin and cytokines (IL-2R, IL-6, IL-8, IL-10 and TNF-α) compared to the non-eosinophil group (P <0.001). The AUC of AEC on admission for predicting ICU transfer among elderly COVID-19 patients was 0.828 (95% CI, 0.732-0.923). The best cut-off value of AEC was 25 cells/μL with a sensitivity of 91% and a specificity of 71%, respectively. Conclusion: AEC on admission is a valid predictive marker for ICU transfer among elderly COVID-19 patients from general isolated wards, and therefore can help case triage and optimize ICU utilization, especially for health care facilities with limited ICU capacity.
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