[Oral hygiene maintenance of locator attachments implant overdentures in edentulous population: A longitudinal study]

OBJECTIVE

To investigate the oral hygiene status of edentulous patients with locator attachments implant overdentures (IOD) and to analyze the relationship among daily hygiene behavior, oral hygiene status and peri-implant diseases.

METHODS

Edentulous patients who received IOD treatment with locator attachments from January 2012 to May 2016 were recruited. Clinical and radiographic examinations were conducted to assess the peri-implant tissue status. Modified plaque index (mPLI), sulcus bleeding index (SBI), gingival index (GI), and probing depth (PD) were recorded and peri-implant marginal bone loss (MBL) was measured using paralleling projection technique. Patients' peri-implant oral hygiene maintainence habits were investigated. The correlation between peri-implant diseases and oral hygiene status and behaviors was analyzed.

RESULTS

Fifty patients (125 implants) with an average follow-up time of 22 months (6-54 months) were enrolled. The mean values of mPLI, SBI, and GI were 1.4±1.2, 0.8±0.7, and 0.7± 0.6, respectively. Average PD was (2.2±0.7) mm. Mesial and distal maginal bone resorptions were (1.1±1.1) mm and (0.9±0.9) mm, respectively. The prevalance of mucositis and peri-implantitis of the implants were 49.6% and 0. The prevelance of mucositis in the patients with poor oral hygiene (mPLI≥2) was 11.9 times as much as that of those with adequate oral hygiene (mPLI<1). The patients who performed oral hygiene procedure on attachments at least twice a day achieved much lower mPLI scores than those who cleaned less than twice a day.

CONCLUSION

Oral hygiene condition in the group of patients with implant overdentures was poor, and it contributed to increased risk of peri-implant mucositis. The prevelance of musositis of the paitients with poor oral hygiene was 11.9 times as much as that of those with proper oral hygiene. Patients wearing IOD should pay more attention to the hygiene of the attachments.

Controlling CRISPR-Cas9 with ligand-activated and ligand-deactivated sgRNAs

The CRISPR-Cas9 system provides the ability to edit, repress, activate, or mark any gene (or DNA element) by pairing of a programmable single guide RNA (sgRNA) with a complementary sequence on the DNA target. Here we present a new method for small-molecule control of CRISPR-Cas9 function through insertion of RNA aptamers into the sgRNA. We show that CRISPR-Cas9-based gene repression (CRISPRi) can be either activated or deactivated in a dose-dependent fashion over a >10-fold dynamic range in response to two different small-molecule ligands. Since our system acts directly on each target-specific sgRNA, it enables new applications that require differential and opposing temporal control of multiple genes.

Molecular characterization and analysis of Mycoplasma pneumoniae among patients of all ages with community-acquired pneumonia during an epidemic in China

BACKGROUND

Analysis of the molecular characteristics of isolates is very important for clinical and epidemiological study of community-acquired pneumonia (CAP) caused by Mycoplasma pneumoniae.

METHODS

Between 2010 and 2012, an epidemic period, M. pneumoniae was isolated from oropharyngeal swabs of consecutive CAP patients. Minimum inhibitory concentrations of macrolides, 23S rRNA gene sequencing, P1 gene and multilocus variable-number tandem-repeat analysis (MLVA) genotyping was conducted.

RESULTS

88.3% (181/205) of the isolates were macrolide-resistant M. pneumoniae (MRMP) and all harbored an A2063 G mutation. The strains were clustered into 7 MLVA types, and P1 type 1 and type 2 lineages were co-circulated (86.3% and 13.7%). Compared with adults, no specific MLVA type contributed to higher M. pneumoniae infection in children (p =  0.14). Similar macrolide profile and genotypes of M. pneumoniae was found between outpatients and inpatients. Significant differences in proportion of P1 types and two main MLVA types 4/5/7/2 and 3/5/6/2 were observed between MRMP and macrolide-sensitive M. pneumoniae (MSMP) (p <  0.001).

CONCLUSIONS

This study demonstrates a comprehensive profile of M. pneumoniae molecular characterization among CAP patients of all age, and provides more evidences on a correlation between MLVA type 4/5/7/2 and macrolide resistance in the setting of high incidence of MRMP.

Enabling genetic analysis of diverse bacteria with Mobile-CRISPRi

The vast majority of bacteria, including human pathogens and microbiome species, lack genetic tools needed to systematically associate genes with phenotypes. This is the major impediment to understanding the fundamental contributions of genes and gene networks to bacterial physiology and human health. Clustered regularly interspaced short palindromic repeats interference (CRISPRi), a versatile method of blocking gene expression using a catalytically inactive Cas9 protein (dCas9) and programmable single guide RNAs, has emerged as a powerful genetic tool to dissect the functions of essential and non-essential genes in species ranging from bacteria to humans1-6. However, the difficulty of establishing effective CRISPRi systems across bacteria is a major barrier to its widespread use to dissect bacterial gene function. Here, we establish 'Mobile-CRISPRi', a suite of CRISPRi systems that combines modularity, stable genomic integration and ease of transfer to diverse bacteria by conjugation. Focusing predominantly on human pathogens associated with antibiotic resistance, we demonstrate the efficacy of Mobile-CRISPRi in gammaproteobacteria and Bacillales Firmicutes at the individual gene scale, by examining drug-gene synergies, and at the library scale, by systematically phenotyping conditionally essential genes involved in amino acid biosynthesis. Mobile-CRISPRi enables genetic dissection of non-model bacteria, facilitating analyses of microbiome function, antibiotic resistances and sensitivities, and comprehensive screens for host-microorganism interactions.

[Evaluation of the fabrication deviation of a kind of milling digital implant surgical guides]

OBJECTIVE

To evaluate the deviation of digital implant surgical guides during fabrication process in the Organical Dental Implant (ODI) system.

METHODS

This study included two parts. The first part was the in vitro study. A resin block with a diagnostic template was used for the planning. After cone beam computed tomography (CBCT) scanning, a surgical guide with eight implants was virtually designed using the ODI system. The guide was milled by a 5-axial numerical controlled milling machine, and an optical scanning was taken to digitalize the guide to a standard tessellation language (STL) form. The STL data were then imported into an ODI software and registered with the original design. The deviation of the sleeves between the design and the STL was measured in the ODI software and set as the golden standard. Then the ODI examination table was used to measure the deviation of the guide during fabrication. Examiners A and B measured 10 times separately. The reliability and the validity of the examination table was calculated. The second part was the in vivo study: The deviation during fabrication of 12 guides designed and fabricated by the ODI system were measured using the examination table.

RESULTS

The standard deviation of the deviation measured using the examination table by examiners A and B were all below 0.40 mm (for the shell reference points) and 0.71 degree (for the angles). No significant difference was found between the two examiners for any implant sites. The result of the examination table was larger than that of the software for the shell reference point (t-test, P<0.05), but no significant difference was found for the angle deviation (t-test, P>0.05). The 45 implants positions in the 12 guides for the in vivo study were examined using the examination table. The deviations at the shell reference points were (1.06±0.29) mm (0.42-1.75 mm), and at the implant tip were (1.12±0.48) mm (0.41-2.44 mm). The angle deviations were (1.42±0.70) degree (0.29-2.96 degree).

CONCLUSION

Deviation is unavoidable during the fabrication process of the guides. The examination table of the ODI system is a reliable and valid tool to measure the deviation during fabrication of the ODI guides. More studies should be designed to research the relationship between the fabrication deviation and the implant insertion deviation.

3D Black-Blood Luminal Angiography Derived from High-Resolution MR Vessel Wall Imaging in Detecting MCA Stenosis: A Preliminary Study

BACKGROUND AND PURPOSE

3D high-resolution vessel wall imaging is increasingly used for intracranial arterial diseases. This study compared the diagnostic performance of black-blood luminal angiography derived from 3D vessel wall imaging with source images of vessel wall imaging and TOF-MRA in detecting middle cerebral artery stenosis.

MATERIALS AND METHODS

Sixty-two patients with suspected MCA atherosclerosis underwent TOF-MRA, vessel wall imaging, and CTA. Intracranial black-blood luminal angiography was created from source images of vessel wall imaging using minimum intensity projection. The degree and length of MCA stenosis were measured on source images of vessel wall imaging, TOF-MRA, and black-blood luminal angiography and compared using CTA as a reference standard.

RESULTS

The image quality of black-blood luminal angiography was diagnostic in most patients. The intra- and interobserver agreement for both stenosis degree and length measurements was excellent for black-blood luminal angiography. It was comparable with that of source images of vessel wall imaging in grading stenosis. Compared with TOF-MRA, black-blood luminal angiography showed significantly higher sensitivity for the detection of severe stenosis (89.3% versus 64.3%, P = .039) and higher specificity for the detection of occlusion (95.4% versus 84.6%, P = .039). Lesion length estimated on source images of vessel wall imaging was significantly greater than that measured by CTA and black-blood luminal angiography (P < .001 and P = .010).

CONCLUSIONS

Black-blood luminal angiography is better than TOF-MRA in detecting severe stenosis and occlusion of the MCA. Compared with source images of vessel wall imaging, it is more accurate in evaluating stenosis length. Black-blood luminal angiography can be produced as a derivative from vessel wall imaging and implemented as an adjunct to vessel wall imaging and TOF-MRA without extra acquisition time.

Epidemiological characterization of respiratory tract infections caused by Mycoplasma pneumoniae during epidemic and post-epidemic periods in North China, from 2011 to 2016

BACKGROUND

Mycoplasma pneumoniae (M. pneumoniae) is a commonly causative pathogen for respiratory tract infections (RTIs) in humans. The epidemiological features of M. pneumoniae infections during post-epidemic, including age distribution and the seasonality of the patients, are not well investigated.

METHODS

We retrospectively analyzed the clinical data of 7835 consecutive RTIs patients (3852 adults and 3983 children) who visited a teaching hospital, and defined an epidemic (2011-2013) and a post-epidemic period (2014-2016). M. pneumoniae was detected by fluorescence-quantatitive PCR in respiratory samples. Informed consent was obtained by all adults and the legal representatives of patients aged < 18 years, and the study was approved by Institutional Review Board of Beijing Chao-Yang Hospital (project approval number 10-KE-49).

RESULTS

The median (IQR) age was 16 (53) years (range < 0-105 years). The M. pneumoniae positive rate was 14.4% (21.2%, epidemic; 6.7%, post-epidemic), with seasonal peaks from late summer to autumn during epidemic, and from fall to winter during post-epidemic period, which was highest in children aged 7-17 years. In epidemic, no statistical difference was found in the positive rates between children and adults among most months (except February, July and August), neither for the positive rates among age groups (P = 0.801). However, in post-epidemic period, significant differences were observed in the positive rates between children and adults in nearly every month (P< 0.05 or P< 0.001, except May), as well as in the positive rates among age groups (P< 0.001). Most of the older patient admissions and all of ICU admissions occurred during the epidemic.

CONCLUSIONS

Different patterns of age distribution and seasonality of M. pneumoniae RTIs between epidemic and post-epidemic periods were reported. Our results suggest that M. pneumoniae should be considered as a possible pathogen in pneumonia patients admitted to the ICU in the setting of an epidemic.

iTRAQ-based proteomic analysis of DMH-induced colorectal cancer in mice reveals the expressions of β-catenin, decorin, septin-7, and S100A10 expression in 53 cases of human hereditary polyposis colorectal cancer

PURPOSE

The aim of this study is to explore the roles of β-catenin, decorin, septin-7, and S100A10 expression in colorectal cancer development.

METHODS

Twenty-five BALB/c mice were divided into five groups; four groups were administrated N,N-dimethylhydrazine for 0, 10, 15, and 20 weeks, and one group was administrated normal saline for 20 weeks. The colons were collected for histopathological analysis. Protein samples prepared from the frozen colon tissues of mice treated with N,N-dimethylhydrazine for the different time points were evaluated using the isobaric tags for relative and absolute quantification (iTRAQ) labeling technique coupled with the 2D liquid chromatography-tandem mass spectrometry analysis. Based on the proteomic analysis results, immunohistochemical staining of β-catenin, decorin, septin-7, and S100A10 was performed in paraffin-embedded mice colorectal tissue, and 53 cases of human hereditary polyposis colorectal cancer samples.

RESULTS

Colorectal cancer was observed in mice treated with N,N-dimethylhydrazine for 20 weeks, and adenomas were observed in mice subjected to the 10-, and 15-week treatments. Seventy-two differentially expressed proteins were involved in the development of cancer as per the iTRAQ and spectrometry analysis. In normal epithelium, adenoma, and cancer from human hereditary polyposis colorectal cancer, S100A10 expression (c2 = 100.989, P = 0.000) was highest in cancer, whereas decorin (c2 = 12.852, P = 0.002) and septin-7 (c2 = 66.519, P = 0.002) expressions were highest in the normal epithelium, which was confirmed via immunohistochemical staining.

CONCLUSIONS

The subcellular localization of β-catenin and decorin, septin-7, and S100A10 expressions are associated with the development of colorectal cancer in mice after N,N-dimethylhydrazine treatment and in human hereditary polyposis colorectal cancers.

Clinical analysis of combined revascularization in treating ischemic Moyamoya disease in adults

OBJECTIVE

The aim of this study was to investigate the clinical efficacy of superficial temporal artery-middle cerebral artery anastomosis (STA-MCA)+encephalo-duro-myo-synangiosis (EDMS) in treating ischemic Moyamoya disease (IMD) in adults.

METHODS

A total of 30 adult patients with IMD were selected to be included in the study; they underwent STA-MCA+EDMS and were followed up for 3 months to 2 years. The digital subtraction angiography findings, modified Rankin scale (mRs) score, and complications of all the patients were compared.

RESULTS

Thirty patients successfully completed the surgery. Three patients had postoperative complications (two patients with cerebral infarction on the surgical side and one patient with poor scalp healing). The postoperative morbidity rate was 10%. Angiography conducted at 3 to 6 months postoperatively showed 28 cases of anastomotic patency; the anastomotic patency rate was 93.3%. The mRs scores of the patients' neurological function 3 months after surgery were lower than those before surgery.

CONCLUSION

STA-MCA+EDMS is effective in treating Moyamoya disease.

The Boltzmann project

The International Committee for Weights and Measures (CIPM), at its meeting in October 2017, followed the recommendation of the Consultative Committee for Units (CCU) on the redefinition of the kilogram, ampere, kelvin and mole. For the redefinition of the kelvin, the Boltzmann constant will be fixed with the numerical value 1.380 649 × 10-23 J K-1. The relative standard uncertainty to be transferred to the thermodynamic temperature value of the triple point of water will be 3.7 × 10-7, corresponding to an uncertainty in temperature of 0.10 mK, sufficiently low for all practical purposes. With the redefinition of the kelvin, the broad research activities of the temperature community on the determination of the Boltzmann constant have been very successfully completed. In the following, a review of the determinations of the Boltzmann constant k, important for the new definition of the kelvin and performed in the last decade, is given.

Exosomes promote cetuximab resistance via the PTEN/Akt pathway in colon cancer cells

Cetuximab is widely used in patients with metastatic colon cancer expressing wildtype KRAS. However, acquired drug resistance limits its clinical efficacy. Exosomes are nanosized vesicles secreted by various cell types. Tumor cell-derived exosomes participate in many biological processes, including tumor invasion, metastasis, and drug resistance. In this study, exosomes derived from cetuximab-resistant RKO colon cancer cells induced cetuximab resistance in cetuximab-sensitive Caco-2 cells. Meanwhile, exosomes from RKO and Caco-2 cells showed different levels of phosphatase and tensin homolog (PTEN) and phosphor-Akt. Furthermore, reduced PTEN and increased phosphorylated Akt levels were found in Caco-2 cells after exposure to RKO cell-derived exosomes. Moreover, an Akt inhibitor prevented RKO cell-derived exosome-induced drug resistance in Caco-2 cells. These findings provide novel evidence that exosomes derived from cetuximab-resistant cells could induce cetuximab resistance in cetuximab-sensitive cells, by downregulating PTEN and increasing phosphorylated Akt levels.

NSs protein of severe fever with thrombocytopenia syndrome virus suppresses interferon production through different mechanism than Rift Valley fever virus

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a newly identified Phlebovirus that causes severe fever with thrombocytopenia syndrome. Our study demonstrated that SFTSV NSs functioned as IFN antagonist mainly by suppressing TBK1/IKKε-IRF3 signaling pathway. NSs interacted with and relocalized TANK-binding kinase 1 (TBK1) into NSs-induced cytoplasmic structures and this interaction could effectively inhibit downstream phosphorylation and dimerization of interferon regulatory factor 3 (IRF3), resulting in the suppression of antiviral signaling and IFN induction. Functional sites of SFTSV NSs binding with TBK1 were then studied and results showed that NSs had lost their IFN-inhibiting activity after deleting the 25 amino acids in N-terminal. Furthermore, the mechanism of Rift Valley fever virus (RVFV) NSs blocking IFN-β response were also investigated. Preliminary results showed that RVFV NSs proteins could neither interact nor co-localize with TBK1 in cytoplasm, but suppressed its expression levels, phosphorylation and dimerization of IRF3 in the subsequent steps, resulting in inhibition of the IFN-β production. Altogether, our data demonstrated the probable mechanism used by SFTSV to inhibit IFN responses which was different from RVFV and pointed toward a novel mechanism for RVFV suppressing IFN responses.

Genomic innovations, transcriptional plasticity and gene loss underlying the evolution and divergence of two highly polyphagous and invasive Helicoverpa pest species

BACKGROUND

Helicoverpa armigera and Helicoverpa zea are major caterpillar pests of Old and New World agriculture, respectively. Both, particularly H. armigera, are extremely polyphagous, and H. armigera has developed resistance to many insecticides. Here we use comparative genomics, transcriptomics and resequencing to elucidate the genetic basis for their properties as pests.

RESULTS

We find that, prior to their divergence about 1.5 Mya, the H. armigera/H. zea lineage had accumulated up to more than 100 more members of specific detoxification and digestion gene families and more than 100 extra gustatory receptor genes, compared to other lepidopterans with narrower host ranges. The two genomes remain very similar in gene content and order, but H. armigera is more polymorphic overall, and H. zea has lost several detoxification genes, as well as about 50 gustatory receptor genes. It also lacks certain genes and alleles conferring insecticide resistance found in H. armigera. Non-synonymous sites in the expanded gene families above are rapidly diverging, both between paralogues and between orthologues in the two species. Whole genome transcriptomic analyses of H. armigera larvae show widely divergent responses to different host plants, including responses among many of the duplicated detoxification and digestion genes.

CONCLUSIONS

The extreme polyphagy of the two heliothines is associated with extensive amplification and neofunctionalisation of genes involved in host finding and use, coupled with versatile transcriptional responses on different hosts. H. armigera's invasion of the Americas in recent years means that hybridisation could generate populations that are both locally adapted and insecticide resistant.

The effects of process technology on the physicochemical properties of peony seed oil

Peony seed oils (PSOs) were prepared using supercritical CO2 (SC) and compared with soxhlet extraction (SE) and mechanical screw press extraction (SPE) methods. The fatty acid compositions of the oils were determined, and the physicochemical properties of the oils, including free radical-scavenging activity, α-amylase and α-glucosidase inhibition, thermal and rheological properties were evaluated. The unsaturated fatty acids in the SE oils were higher than SC and SPE oils due to the higher percentage of olefinic, allylic methylene and allylic methine protons in the SE oils. The SPE oils also displayed the highest DPPH and ABTS+ radical scavenging activity at the tested concentrations. However, the SE oils showed stronger inhibitory effects on α-amylase and α-glucosidase enzymes under in vitro conditions when compared with the other oil samples. The three oils had similar melting and crystalline point due to similar contents of fatty acids (FAs). The SC oils had a lower Ea than the others.

Phosphoglycerate mutase 1 promotes cancer cell migration independent of its metabolic activity

Phosphoglycerate mutase 1 (PGAM1) is a glycolytic enzyme that coordinates glycolysis and biosynthesis to promote cancer growth via its metabolic activity. Here, we report the discovery of a non-metabolic function of PGAM1 in promoting cancer metastasis. A proteomic study identified α-smooth muscle actin (ACTA2) as a PGAM1-associated protein. PGAM1 modulated actin filaments assembly, cell motility and cancer cell migration via directly interacting with ACTA2, which was independent of its metabolic activity. The enzymatically inactive H186R mutant retained its association with ACTA2, whereas 201-210 amino acids deleted PGAM1 mutant lost the interaction with ACTA2 regardless of intact metabolic activity. Importantly, PGAM1 knockdown decreased metastatic potential of breast cancer cells in vivo and PGAM1 and ACTA2 were jointly associated with the prognosis of breast cancer patients. Together, this study provided the first evidence revealing a non-metabolic function of PGAM1 in promoting cell migration, and gained new insights into the role of PGAM1 in cancer progression.

[Predictive value of dynamic enhanced MR synovial wash in rate in progression to rheumatoid arthritis in patients with undifferentiated arthritis]

Objective: To investigate the predictive value of dynamic enhanced MR synovial wash in rate (WASHIN) in progression to rheumatoid arthritis (RA) in patients with undifferentiated arthritis (UA). Methods: The data of dynamic enhanced MR synovial WASHIN and C- reactive protein (CRP) of 33 patients with UA were analyzed between October 2014 and January 2016 from Tianjin First Center Hospital, so as to evaluate the correlation between the two indicators. According to the value of CRP, the patients were divided into two groups, the CRP>8 mg/L for CRP positive group (18 cases), CRP≤8 mg/L for CRP negative group (15 cases). Ranked sum test was used to compare the difference of WASHIN between two groups. The ROC curve analysis was carried out to test the diagnostic power of WASHIN. Results: In 33 patients with UA, the correlation between WASHIN and CRP was positive, r=0.767, P<0.01; as for the WASHIN, there was significant difference between CRP positive group(49.51±19.79)/s and CRP negative group(19.90±14.51)/s (P<0.01). 9 cases were clinically diagnosed with RA during follow-up, of which 8 cases for CRP positive group and 1 case for CRP negative group. The biggest area under the ROC curve of synovial WASHIN was 0.944, the biggest Youden index was 0.85, sensitivity was 100.0%, specificity was 87.5%. 2 cases were clinically diagnosed with osteoarthrosis during follow-up, synovial WASHIN respectively of 18.42 and 21.48 /s. Conclusion: Synovial WASHIN can improve the sensitivity and specificity to predict the prognosis from UA to RA, and can provide certain guiding significance for clinical work.