Melatonin mitigates cadmium and aluminium toxicity through modulation of antioxidant potential in Brassica napus L

Melatonin has emerged as an essential molecule in plants, due to its role in defence against metal toxicity. Aluminium (Al) and cadmium (Cd) toxicity inhibit rapeseed seedling growth. In this study, we applied different doses of melatonin (50 and 100 µm) to alleviate Al (25 µm) and Cd (25 µm) stress in rapeseed seedlings. Results show that Al and Cd caused toxicity in rapeseed seedling, as evidenced by a decrease in height, biomass and antioxidant enzyme activity. Melatonin increased the expression of melatonin biosynthesis-related Brassica napus genes for caffeic acid O-methyl transferase (BnCOMT) under Al and Cd stress. The genes BnCOMT-1, BnCOMT-5 and BnCOMT-8 showed up-regulated expression, while BnCOMT-4 and BnCOMT-6 were down-regulated during incubation in water. Melatonin application increased the germination rate, shoot length, root length, fresh and dry weight of seedlings. Melatonin supplementation under Al and Cd stress increased superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, proline, chlorophyll and anthocyanin content, as well as photosynthesis rate. Both Cd and Al treatments significantly increased hydrogen peroxide and malondialdehyde levels in rapeseed seedlings, which were strictly counterbalanced by melatonin. Analysis of Cd and Al in different subcellular compartments showed that melatonin enhanced cell wall and soluble fractions, but reduced the vacuolar and organelle fractions in Al- and Cd-treated seedlings. These results suggest that melatonin-induced improvements in antioxidant potential, biomass, photosynthesis rate and successive Cd and Al sequestration play a pivotal role in plant tolerance to Al and Cd stress. This mechanism may have potential implications in safe food production.

Cascaded multi-scale convolutional encoder-decoders for breast mass segmentation in high-resolution mammograms

This paper addresses breast mass segmentation from high-resolution mammograms. To cope with strong class imbalance, huge diversity of size, shape, texture and contour as well as limited receptive field, mass segmentation is achieved through a multi-scale cascade of deep convolutional encoder-decoders without any pre-detection scheme. Multi-scale information is integrated using auto-context to make long-range spatial context arising from lower scale impact training at higher resolution. The pipeline is trained end-to-end to benefit from simultaneous segmentation refinement performed at each level. It incorporates transfer learning and fine tuning from DDSM-CBIS to INbreast datasets to further improve mass delineations. The comprehensive evaluation provided for high-resolution INbreast images highlights promising model generalizability against standard encoder-decoder strategies.

[Influence on physical development of children aged 18 months from HIV-positive mothers for prevention mother to child transmission of HIV]

Objective: To explore influence on physical development of children aged 18 months from HIV-positive mothers for prevention mother to child transmission of HIV (PMTCT) in Guangxi Zhuang autonomous region, and provide evidence for the improvement PMTCT program. Methods: This retrospective case control study was conducted in 554 HIV negative infants aged 18 months whose HIV positive mothers had received PMTCT services reported through PMTCT system database from January 1, 2010 to December 31, 2017 and 1 109 healthy infants born in 2017, whose mothers were healthy, in Lingshan, Luzhai, and Hengxian counties, ranking top three counties with high HIV infection prevalence, in Guangxi. PMTCT data and physical development data such as height, weight and head circumference of children aged 18 months were collected. The physical dysplasia in the infants was defined as at least one of the three main indicators of height, weight and head circumference below the normal range. Results: The number of HIV-positive mother and their infants in the case group were 667 and 554 respectively, and the PMTCT rates were 91.15% (608/667) and 96.57% (535/554) respectively. HIV positive rate, mortality rate and mother to child transmission rate of the infants aged 18 months were 1.44% (8/554), 3.07% (17/554) and 1.91% (8/418) respectively, and the physical examination results of the infants aged 18 months showed that the physical dysplasia rate was 30.51% (169/554). Among the 1 109 infants in the control group, the physical dysplasia rate was 9.83% (109/1 109). The difference between the case group and the control group was significant (P<0.01). Conclusion: The PMTCT rates of HIV positive mother and their children were more than 90.00%, respectively. However, poor physical development rate of infants aged 18 months were more than 30.00%. The possible influence of PMTCT on physical development of the infants aged 18 months of HIV positive mother's needs to be further studied.

Association between gut microbiome and T lymphocytes among different primary tumor sites of patients with metastatic colorectal cancer

e16013

Background: Different primary tumor sites could impact colorectal cancer (CRC)’s survival outcomes and treatment effects. Previous studies had found that gut micro-biome distributions were different between left and right colon cancer(LCC, RCC). Out study aimed to further investigate the association between micro-biome and T lymphocytes among different tumor sites of patients with metastatic CRC. Methods: Between April 2018 and Mars 2019, we enrolled 40 metastatic CRC patients in Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China. We collected patients’ stool samples for micro-biome analysis by 16s rRNA sequencing approaches, as well as patients’ blood samples to analyses T lymphocyte subsets by flow cytometry methods. The study had been proved by ethics committee of Xiyuan Hospital (2016XLA122-1). All patients consented before enrollment. Results: Among 40 patients, 28% were female, with average age of 63±15 years old. There were 10 RCC, 9 LCC and 21 rectal cancer(RC) patients. Alpha diversity analysis showed that sobs index of the micro-biome of patients with RC and RC was significantly higher than whom were RCC(254.89±99, 247±89 versus.[vs.]101.17±51, p= 0.001). PCoA analysis on OTU level detected that first principal component[PC1] (26.24%) could be separated significantly between RCC and LCC( p= 0.048), as well as between RC and RCC (PC1,14.17%, p= 0.024). Community analysis showed that the proportion of Bacteroidetes was significantly higher in patients with RCC than whom with LCC and RC( p= 0.009). Conversely, the proportion of Firmicutes, Proteobacteria and Verrucomicrobia were higher in LCC patients than others( p= 0.37, 0.047 and 0.032 respectively). Canonical Correlation Analysis (CCA) analysis proved that the CD4+ and CD8+ T cells counts were environmental factors, which were significantly associated with certain micro-biome and samples from different tumor sites( p= 0.037 and 0.01 respectively). Trends showed that CD4+ T cells were positively related with samples of RC and bacteria parabacteroides and bifidobacterium, while CD8+ T cells were positively related with samples of RCC and bacteria Lachnospira, Sutterella and Bacteroides. Conclusions: In our study, we found that patients with LCC and RC had more beneficial gut micro-biome than whom with RCC. In addition, such difference might be associated with body T cell immunity.

Ultrafast Control of Excitonic Rashba Fine Structure by Phonon Coherence in the Metal Halide Perovskite CH_{3}NH_{3}PbI_{3}

We discover hidden Rashba fine structure in CH_{3}NH_{3}PbI_{3} and demonstrate its quantum control by vibrational coherence through symmetry-selective vibronic (electron-phonon) coupling. Above a critical threshold of a single-cycle terahertz pump field, a Raman phonon mode distinctly modulates the middle excitonic states with persistent coherence for more than ten times longer than the ones on two sides that predominately couple to infrared phonons. These vibronic quantum beats, together with first-principles modeling of phonon periodically modulated Rashba parameters, identify a threefold excitonic fine structure splitting, i.e., optically forbidden, degenerate dark states in between two bright ones with a narrow, ∼3  nm splitting. Harnessing of vibronic quantum coherence and symmetry inspires light-perovskite quantum control and sub-THz-cycle "Rashba engineering" of spin-split bands for ultimate multifunction device.

[Depletion of PRDM9 inhibited the osteogenic differentiation potential of periodontal ligament stem cells]

Objective: To investigate the effect of PR domain zinc finger protein 9 (PRDM9), one of the histone methylated transferases, on osteogenic differentiation ability of periodontal ligament mesenchymal stem cells (PDLSC). Methods: PDLSC with PRDM9 gene knocked down by PRDM9 shRNA using recombinant lentiviral vector were allocated into the PRDM9sh group, and the transfected shRNA was as the control group. The gene expression efficiency was evaluated by reverse transcription polymerase chain reaction (RT-PCR). Alkaline phosphatase activity (ALP), alizarin red staining, mineralization and osteocalcin, which belongs to osteogenic differentiation markers detected by RT-PCR and Western blotting to detect the osteogenic differentiation ability of stem cells from periodontal ligaments in vitro. In vivo, PRDM9sh and control group cells was transplanted into the dorsal dermal to explore the osteogenesis. The area percentage of new osteogenic tissue was calculated by image pro software and statistically analyzed. Results: RT-PCR results showed that the relative expression of PRDM9 gene in PRDM9sh (0.460±0.017) was significantly lower than that in control group (1.000±0.107) (P<0.05). The results of ALP activity determined at 5 days postinduction in a significant decrease in PRDM9sh cells (0.762±0.063) compared with control group (1.225±0.058) (P<0.01). Alizarin red staining induced by osteogenesis at 2 weeks and 3 weeks showed that the staining of PRDM9sh was significantly lighter than that in control group. Quantitative calcium analysis results showed that the calcium ion concentration induced by osteogenesis at 2 weeks and 3 weeks [(0.071±0.004), (0.075±0.001)] in PRDM9sh was significantly lower than that in control group at 2 weeks and 3 weeks [(0.282±0.006), (0.485+0.004)] (P<0.01). RT-PCR results showed that the relative expression of osteocalcin mRNA in PRDM9sh (1.059±0.148) was significantly lower than that in control group at 2 weeks (2.542±0.190) (P<0.01). Western blotting results showed that osteocalcin expression in PRDM9sh was significantly lower than that in control group at 1 and 2 weeks after osteogenesis induction. Animal transplantation experiments results indicated that PRDM9 significantly inhibited the osteogenesis of PDLSC in vivo, and the proportion of osteogenic area calculated showed that the osteogenic capacity of PRDM9sh [(3.8±2.41)%] was significantly lower than that in control group [(24.54±7.06)%](P<0.05). Conclusions: Depletion of PRDM9 repressed the osteogenic differentiation of stem cells from periodontal ligament in vitro and in vivo.

[Curative effect observation of application of the snare in epiglottic cystectomy by arc-shaped laryngoscopy]

Objective:To evaluate the effect of the epiglottic cystectomy by arc-shaped video laryngoscopy combined with snare. Method:The clinical data of 42 patients with epiglottic cysts were retrospectively analyzed. Forty-two patients with epiglottis cyst were treated by arc-shaped video laryngoscopy combined with snare. Result:All 42 cases were completely resected at one time without obvious complications and the cure rate was 100%. Moreover, the short operation time（5-20 min） and the minor hemorrhage（1-10 ml） were observe. There was no recurrence after 6 to 33 months follow-up. Conclusion:The epiglottic cystectomy by arc-shaped video laryngoscopy combined with snare has the advantages of broad vision, easy operation, minimal invasion, rapid recovery and good curative effect, it is worthy to be popularized in clinical application.

LncRNA PCAT-1 regulates the proliferation, metastasis and invasion of cervical cancer cells

OBJECTIVE

To investigate the effects of long non-coding RNA (lncRNA) PCAT-1 on the proliferation, metastasis, and invasion of cervical cancer cells.

MATERIALS AND METHODS

LncRNA PCAT-1 small interfering RNA (siRNA) and negative siRNA were transfected into cervical cancer cell lines and the expression of lncRNA PCAT-1 in cells was confirmed by Real-time quantitative polymerase chain reaction (qPCR). Cell counting kit-8 (CCK-8) and colony formation assay were applied to detect the effect of lncRNA PCAT-1 on cell proliferation. The wound-healing assay was applied to test the effect of lncRNA PCAT-1 on cell metastasis. Matrigel cell invasion assay was performed to detect the impact of lncRNA PCAT-1 expression on invasion.

RESULTS

After transfected with the long non-coding PCAT-1 siRNA into cervical cancer cell lines for 48 h, the lncRNA PCAT-1 cells were significantly down-regulated. The results of CCK-8, clonogenic and wound-healing assay showed that the decreased expression of lncRNA PCAT-1 attenuated the proliferation and metastasis of cells. The results of matrigel cell invasion assay manifested that the decreased expression of lncRNA PCAT-1 could reduce the invasion ability. The up-regulation of lncRNA PCAT-1 was associated with poor prognosis of patients with cervical cancer.

CONCLUSIONS

LncRNA PCAT-1 siRNA transfected into cervical cancer cell lines can effectively lower the expression of lncRNA PCAT-1, while lncRNA PCAT-1 expression can inhibit the proliferation, metastasis and invasion abilities of cervical cancer cells.

Electrophysiological effects of melatonin on rat trigeminal ganglion neurons that participate in nociception in vitro

OBJECTIVE

Melatonin (MT) is a hormone mainly produced by the pineal gland. It may be involved in the regulation of nociception, the mechanisms of which remain unclear. In the present study, electrophysiological effects of MT on neurons were studied.

MATERIALS AND METHODS

The cultured neurons were isolated from Sprague-Dawley rats trigeminal ganglia (TG). The neuron was voltage clamped using the whole cell patch clamp technique. We recorded resting membrane potential, action potential threshold and number, action potential duration and GABA-activated inward currents in the presence of 0.01 μM, 10 μM MT, and in the absence of MT.

RESULTS

In the presence of high concentration of MT, the spontaneous action potential disappeared and action potential threshold was significantly increased. GABA-activated inward currents were recorded and blocked by GABAA receptor antagonist, bicuculline, in the majority of TG neurons (91% 40/44). Continuous perfusion of MT could cause a decrease of GABA-activated currents. The inhibiting effect was dose-dependent and irreversible.

CONCLUSIONS

The results suggest that MT has several electrophysiological effects on TG neurons, which may be involved in the peripheral mechanisms of orofacial pain.

Kaempferol attenuates imiquimod-induced psoriatic skin inflammation in a mouse model

Psoriasis is an immune-mediated inflammatory skin disease that mainly affects the skin barrier. Treatment for psoriasis mainly includes conventional immunosuppressive drugs. However, long-term treatment with global immunosuppressive agents may cause a variety of side effects, including nephrotoxicity and infections. Kaempferol, a natural flavonol present in various plants, is known to possess potent anti-inflammatory, anti-oxidant and anti-cancerous properties. However, it is unknown whether kaempferol is also anti-psoriatic. Here we established an imiquimod (IMQ)-induced psoriatic mouse model to explore the potential therapeutic effects of kaempferol on psoriatic skin lesions and inflammation. In this study, we demonstrated that treatment with kaempferol protected mice from developing psoriasis-like skin lesions induced by topical administration of IMQ. Kaempferol reduced CD3⁺ T cell infiltration and gene expression of major proinflammatory cytokines, including interleukin (IL)-6, IL-17A and tumor necrosis factor (TNF)-α, in the psoriatic skin lesion. It also down-regulated proinflammatory nuclear factor kappa B (NF-κB) signaling in the skin. The therapeutic effects were associated with a significant increase in CD4⁺ forkhead box protein 3 (FoxP3)⁺ regulatory T cell (T_reg ) frequency in the spleen and lymph nodes as well as FoxP3-positive staining in the skin lesion. Conversely, depletion of CD4⁺ CD25⁺ T_regs reversed the therapeutic effects of kaempferol on the skin lesion. Kaempferol also lowered the percentage of IL-17A⁺ CD4⁺ T cells in the spleen and lymph nodes of IMQ-induced psoriatic mice. Finally, kaempferol suppressed the proliferation of T cells in vitro and their mTOR signaling. Thus, our findings suggest that kaempferol may be a therapeutic drug for treating human psoriasis in the near future.