The association between MICA/MICB polymorphism and respiratory syncytial virus infection in children

MICA/MICB gene polymorphisms are related to several cancers and infectious diseases, but there are no reports on the association between MICA/MICB gene polymorphisms and respiratory syncytial virus (RSV) infection. To clarify the association between MICA/MICB gene polymorphisms and infection of RSV in children, we collected fresh blood samples from paediatric patients with and without pneumonia after RSV infection. The MICA/MICB alleles were characterized by PCR sequence-specific primers (PCR-SSP) and PCR sequence-based genotyping (PCR-SBT), and then, the frequency of the MICA/MICB alleles and haplotypes was calculated. The results showed that the frequencies of MICA*002:01 and MICA-A9 in RSV-infected patients were significantly lower than in controls (9% vs. 20%, pc = 0.04). The allele frequency of MICA*002:01 in pneumonia patients (8%) and nonpneumonia patients (9%) was significantly lower than in controls (20%, pc = 0.02). MICA*002:01-MICB*008(Δrel = 0.616), MICA*009-MICB*016 (Δrel = 0.506), and MICA*045-MICB*014 (Δrel = 0.700) showed linkage disequilibrium in patients infected with RSV. The haplotype frequency of MICA*002:01-MICB*005:02 in RSV-infected patients was significantly lower than in controls (10% vs. 16%, pc = 0.033). In conclusion, allele MICA*002:01/A9 and haplotype MICA*002:01-MICB*005:02 were negatively associated with RSV respiratory tract infections.

Role of toll-like receptor 2 in inflammation and alveolar bone loss in experimental peri-implantitis versus periodontitis

BACKGROUND AND OBJECTIVE

Peri-implantitis and periodontitis are different entities in immune characteristics even though they share similar features in clinical and radiologic signs. Toll-like receptor 2 (TLR-2), one of the key pathogen-recognition receptors in the innate immune system, plays an important role in the progression of periodontitis. However, the role of TLR-2 in peri-implantitis remains unclear. The objective of this study was to investigate the role of TLR-2 in inflammation and alveolar bone loss in a murine model of ligature-induced peri-implantitis and to compare it with ligature-induced periodontitis.

MATERIAL AND METHODS

Smooth-surface titanium implants were placed in the alveolar bone of the left maxillary molars of wild-type (WT) and Tlr2 knockout (Tlr2-KO) mice 6 weeks after tooth extraction. Silk ligatures were applied to the left implant fixtures and the right maxillary second molars to induce peri-implantitis and periodontitis 4 weeks after implant placement. Two weeks after ligation, bone loss around the implants and maxillary second molars was analysed by micro-computed tomography (micro-CT), and inflammation around the implants and maxillary second molars was assessed at the same time point using histology and TRAP staining, respectively. Expression of mRNA for proinflammatory cytokines (interleukin-1β [Il1β], tumor necrosis factor-α [Tnfα]), an anti-inflammatory cytokine (interleukin-10 [Il10]) and osteoclastogenesis-related cytokines (Rankl, osteoprotegerin [Opg]) were evaluated, in gingival tissue, using real-time quantitative PCR (RT-qPCR).

RESULTS

The success rate of implant osseointegration was significantly higher in Tlr2-KO mice (85.71%) compared with WT mice (53.66%) (P = .0125). Micro-CT revealed significantly decreased bone loss in Tlr2-KO mice compared with WT mice (P = .0094) in peri-implantitis. The levels of mRNA for Il1β (P = .0055), Tnfα (P = .01) and Il10 (P = .0019) in gingiva were significantly elevated in the peri-implantitis tissues of WT mice, but not in Tlr2-KO mice, compared with controls. However, the gingival mRNA ratios of Rankl/Opg in peri-implant tissues were significantly upregulated in both WT (P = .0488) and Tlr2-KO (P = .0314) mice. Ligature-induced periodontitis exhibited similar patterns of bone loss and inflammatory cytokine profile in both groups of mice, except that the level of Il10 was elevated (P = .0114) whereas the Rankl/Opg ratio was not elevated (P = .9755) in Tlr2-KO mice compared with control mice. Histological findings showed increased numbers of TRAP-positive cells and infiltrated inflammatory cells in ligature-induced peri-implantitis in both WT (P < .01) and Tlr2-KO mice (P < .05), and the numbers of both types of cell were significantly higher in WT mice than in Tlr2-KO mice (P < .01).

CONCLUSION

This study suggests that TLR-2 mediates bone loss in both peri-implantitis and periodontitis. However, different molecular features may exist in the pathogenesis of the two diseases.

The Role of Sulfur Dioxide in Stratospheric Aerosol Formation Evaluated Using In-Situ Measurements in the Tropical Lower Stratosphere

Stratospheric aerosols (SAs) are a variable component of the Earth's albedo that may be intentionally enhanced in the future to offset greenhouse gases (geoengineering). The role of tropospheric-sourced sulfur dioxide (SO₂) in maintaining background SAs has been debated for decades without in-situ measurements of SO₂ at the tropical tropopause to inform this issue. Here we clarify the role of SO₂ in maintaining SAs by using new in-situ SO₂ measurements to evaluate climate models and satellite retrievals. We then use the observed tropical tropopause SO₂ mixing ratios to estimate the global flux of SO₂ across the tropical tropopause. These analyses show that the tropopause background SO₂ is about 5 times smaller than reported by the average satellite observations that have been used recently to test atmospheric models. This shifts the view of SO₂ as a dominant source of SAs to a near-negligible one, possibly revealing a significant gap in the SA budget.

Generation of Mesenchymal-Like Stem Cells From Urine in Pediatric Patients

OBJECTIVES

Mesenchymal stem cells (MSCs) have been widely used for regenerative medicine. Traditionally, the procedures of MSC isolation are usually invasive and time-consuming. Urine is merely a body waste, and recent studies have suggested that urine represents an alternative source of stem cells. We, therefore, determined whether the possibility of isolating mesenchymal-like stem cells was practical from human urine.

METHODS

A total of 16 urine samples were collected from pediatric patients. Urine-derived cells were isolated, expanded, and identified for specific cell surface markers using flow cytometry. Cell morphology was observed by microscopy. Osteogenic and adipogenic differentiation potential were determinded by culturing cells in specific induction medium, and assessed by alkaline phosphatase and oil red O stainings, respectively.

RESULTS

Clones were established and passaged successfully from primary cultures of urine cells. Cultured urine-derived cells at passage 3 were fusiform and arranged with certain directionality. Urine-derived cells at passage 5 displayed expressions of cell surface markers (CD29, CD105, CD166, CD90, and CD13). There was no expression of the general hematopoietic cell markers (CD45, CD34, and HLA-DR). Under in vitro induction conditions, urine-derived cells at passage 5 were able to differentiate into osteoblasts, but not adipocytes.

CONCLUSIONS

Urine may be a noninvasive source for mesenchymal-like stem cells. These cells could potentially provide a new source of autologous stem cells for regenerative medicine and cell therapy.

[Effect of inhibiting perivascular adhesion on intimal hyperplasia of the vein grafts in rabbits]

Objective: To investigate the effect of preventing perivascular adhesion with topical application of sodium hyaluronate on intimal hyperplasia of the vein grafts in rabbits. Methods: Twenty-four male New Zealand white rabbits, aged 5 months, were randomly divided into 2 groups: Group A and B (n=12 rabbits per group). Artery defect model was established by cutting about 1 cm artery from the middle part of the dissociated left common carotid artery. A section about 3 cm was cut from the right external jugular vein, and the harvested vein was inverted and end-to-end anastomosed to the artery defect. After anastomosis, the adventitia and two anastomosis of the grafted veins in group A was applied 0.2 ml sodium hyaluronate locally to, and corresponding site in Group B was served as a control, but with the sterile normal saline. The grafted veins were obtained 1, 2 and 4 weeks after operation, HE staining and Masson staining were preformed for histological changes of grafted vein wall, proliferating cell nuclear antigen (PCNA) and platelet-derived growth factor (PDGF) immunohistochemistry staining were conducted for proliferation and expression and distribution of PDGF of the grafted vein. Results: The macroscopic and histological observation showed that the perivascular adhesions in Group A were looser when compared with those in Group B. The thickness of the intima, the degree of intima hyperplasia of 2 groups at different time points were as follows: at 1 week after operation, group A[(25.5±3.9) μm, (1.2±0.1) ]and group B[(26.2±4.2)μm, (1.2±0.1)]; at 2 weeks after operation, group A[(44.3±2.5)μm, (1.2±0.1)]and group B[(51.0±3.8)μm, (1.4±0.0)]; at 4 weeks after operation, group A[(69.9±6.8)μm, (1.5±0.1)] and group B[(84.4±6.4)μm, (1.7±0.1)]. Group A was inferior to group B in terms of the above three parameters 2 and 4weeks after operation (P<0.05). Cell proliferation index of intima and that of media were as follows: at 1 week after operation, group A (7.4±2.2), (21.5±3.2) and group B (11.5±2.0), (28.6±4.5); at 2 weeks, group A (20.0±3.2), (35.8±3.4) and group B (26.8±4.1), ( 42.6±4.2); at 4 weeks, group A (11.4±2.0), (22.1±2.7) and group B (15.5±2.4, 28.6±3.9). Group A was inferior to group B in terms of cell proliferation index of intima and media 1, 2 and 4 weeks after operation (P<0.05). The percentage of PDGF-positive cells of intima, media and adventitia was as follows: at 1 week after operation, group A (7.7±1.6), (19.6±3.7), (2.5±1.5) and group B (7.6±2.4), (20.6±4.4), (10.3±2.3); at 2 weeks after operation, group A (11.4±2.6), (19.8±3.1), (12.9±3.3) and group B (19.5±3.5), ( 30.6±5.2), (30.5±5.8); at 4 weeks after operation, group A (6.2±1.9), ( 11.1±2.8), (10.2±2.4) and group B (10.5±2.0), (18.6±3.2), (26.5±3.8). Group A was inferior to group B in terms of the percentage of PDGF-positive cells of intima, media and adventitia 2 and 4 weeks after operation (P<0.05) and Group A was inferior to group B that of adventitia 1 week after operation (P<0.05). Conclusion: Preventing perivascular adhesion with topical application of sodium hyaluronate can inhibit intimal hyperplasia.

Sargassum fusiforme Polysaccharide Rejuvenat es the Small Intestine in Mice Through Altering its Physiol ogy and Gut Microbiota Composition

BACKGROUND AND OBJECTIVE

Aging can result in a progressive decline in cellular protection and physiological function. The physiological status and microbiota of the intestine are intensively linked to the aging process. Numerous studies have suggested that Sargassum fusiforme polysaccharides possess antioxidant and antiaging activities. However, it remains unclear as to whether S. fusiforme polysaccharides can prevent the insult of oxidant and aging through modulating the physiological status and microbiota of the intestine.

METHODS

To assess the cytoprotective effect of S. fusiforme polysaccharides (SFPS) in the small intestine of mice embarking on the aging process, we compared the expressions of Nrf2 and several representative markers (SOD-2, CAT, NQO1 and HO-1) of the Nrf2/ARE signaling pathway in the small intestine of male ICR mice fed with a control diet with those of mice fed with a SFPS-containing diet. In addition, the overall compositional changes in the small intestine microbiota were determined by 16s rDNA sequencing followed by alpha and beta diversity analyses.

RESULTS

The results showed that dietary intake of SFPS could ameliorate the declined cytoprotective capacity of the small intestine by upregulating the Nrf2/ARE signaling pathway. Moreover, SFPS could partially rejuvenate the overall status of the small intestine microbiota.

CONCLUSION

The results suggested that dietary SFPS may promote the health condition of the small intestine, consequently leading to a healthy aging.

Degree of Conversion and Polymerization Shrinkage of Bulk-Fill Resin-Based Composites

This study evaluated the degree of conversion (DC) and polymerization shrinkage (PS) of contemporary bulk-fill resin-based composites (RBCs) including giomer materials. Two giomer bulk-fill (Beautifil Bulk Restorative [BBR], Beautifil Bulk Flowable [BBF]), two nongiomer bulk-fill (Tetric N-Ceram Bulk-fill [TNB], Smart Dentin Replacement [SDR]), and three conventional non–bulk-fill (Beautifil II [BT], Beautifil Flow Plus [BF], Tetric N-Ceram [TN]) RBCs were selected for the study. To evaluate the DC, disc-shaped specimens of 5-mm diameter and 2-mm, 4-mm, and 6-mm thickness were fabricated using customized Teflon molds. The molds were bulk filled with the various RBCs and cured for 20 seconds using a light-emitting diode curing light with an irradiance of 950 mW/cm2. The DC (n=3) was determined by attenuated total reflectance Fourier transform infrared spectroscopy by computing the spectra of cured and uncured specimens. PS (n=3) was measured with the Acuvol volumetric shrinkage analyzer by calculating specimen volumes before and after light curing. The mean DC for the various materials ranged from 46.03% to 69.86%, 45.94% to 69.38%, and 30.65% to 67.85% for 2 mm, 4 mm, and 6 mm, respectively. For all depths, SDR had the highest DC. While no significant difference in DC was observed between depths of 2 mm and 4 mm for the bulk-fill RBCs, DC at 2 mm was significantly greater than 6 mm. For the conventional RBCs, DC at 2 mm was significantly higher than at 4 mm and 6 mm. Mean PS ranged from 1.48% to 4.26% for BBR and BF, respectively. The DC at 2 mm and PS of bulk-fill RBCs were lower than their conventional counterparts. At 4 mm, the DC of giomer bulk-fill RBCs was lower than that of nongiomer bulk-fill materials.

[Durability of protective effect of resin-based coating material on root surface]

OBJECTIVE

To compare the durability of resin-based root-surface coating material and all-in-one self-etching adhesive on root surface in vitro.

METHODS

Human extracted premolars or molars with intact roots were selected. The cementum was removed using a periodontal scaler to expose root dentin. The root surface was coated with an acid-resistant nail varnish, leaving a window of 3 mm×3 mm on the exposed dentin.The window was covered with either PRG Barrier Coat (PRG) or Clearfil S3 Bond (CS3). After water aging for 14 d, specimens were immersed in acid buffer at pH 4.5 for 4 d and the demineralization buffer was changed every 24 h. Then the specimen was split longitudinally through the center of the 'window' and the cross-sectional surface was observed with scanning electron microscope (SEM). After fixed and dehydrated, the prepared samples were coated with platinum. The coating material, root dentin and the interface was observed by scanning electron microscope (SEM). The thickness of the coating material was measured on the SEM images. Regarding toothbrush wear test, coronal dentindisks were prepared and covered with PRG and CS3, respectively. After storage in water for 24 h, the specimen was subjected to the toothbrush wear tester for 100, 200, 300, 500, 700, 1 500 brushing cycles. A slurry of fluoride toothpaste (1:2 ratio of toothpaste and deionized water by weight) was used and the brushing load was 300 N. The surface microstructure of remaining coating material was analyzed using SEM. The wear depths were determined by a profilometer. Statistical analysis was performed with SPSS 20.0 by one-way ANOVA. The level of significance was at 0.05.

RESULTS

Application of PRG Barrier Coat produced a coating layer of (47.1±27.3) μm, while CS3 presented a thin film of (5.7±2.1) μm in thickness. The exposed dentin was hermetically sealed and no obvious gap was observed at the interface in both PRG and CS3 groups. There was no dentin demineralization observed in both groups after water aging. The wear depths of PRG and CS3 increased along with the numbers of brushing cycles. PRG wore at a significant lower pace than CS3 did (P<0.05).

CONCLUSION

PRG coating resin had similar performances as CS3 on protecting root dentin from demineralization after water aging. What's more, PRG demonstrated a higher toothbrush wear resistance than CS3. We concluded that PRG Barrier Coat contained S-PRG filler may be an effective coating material for protecting exposed root from both chemical and mechanical challenges. Further studies should be carried out to evaluate the long-term reliability of the rootsurface coating materials under the clinical setting.

Quantitative trait loci mapping of the stigma exertion rate and spikelet number per panicle in rice (Oryza sativa L.)

The stigma exertion rate is a polygenic inherited trait that is important for increased seed yield in hybrid rice breeding. To identify quantitative trait loci (QTL) associated with high stigma exertion rate, we conducted QTL mapping using 134 recombinant inbred lines derived from XieqingzaoB and Zhonghui9308, which have high and low stigma exertion rates, respectively. A total of eight QTLs (qSES6, qSSE11, qDSE1a, qDSE1b, qDSE10, qDSE11, qTSE1, and qTSE11) for single stigma exertion, double stigma exertion, and total stigma exertion were detected. The locations of qSSE11 and qTSE11 have not been previously reported, and the qDSE11 allele from parent XQZB exhibited a positive additive effect. In addition, three QTLs (qSNP1, qSNP3a, and qSNP3b), for spikelet number per panicle were identified. Of note, one QTL (qSNP1) was detected in two different environments (Hainan and Zhejiang). To evaluate the advantage of exerted stigma for cross-pollination, single, dual, and total stigma exertion should be considered separately for future genetic improvement in the production of rice hybrid seeds. In addition, this study provides information for fine mapping, gene cloning, and marker assisted selection, with emphasis on the latter.