Proteoglycan 4 (lubricin) is a highly sialylated glycoprotein associated with cardiac valve damage in animal models of infective endocarditis.

Streptococcus gordonii and Streptococcus sanguinis are primary colonizers of tooth surfaces and are generally associated with oral health, but can also cause infective endocarditis (IE). These species express "Siglec-like" adhesins that bind sialylated glycans on host glycoproteins, which can aid the formation of infected platelet-fibrin thrombi (vegetations) on cardiac valve surfaces. We previously determined that the ability of S. gordonii to bind sialyl T-antigen (sTa) increased pathogenicity, relative to recognition of sialylated core 2 O-glycan structures, in an animal model of IE. However, it is unclear when and where the sTa structure is displayed, and which sTa-modified host factors promote valve colonization. In this study, we identified sialylated glycoproteins in the aortic valve vegetations and plasma of rat and rabbit models of this disease. Glycoproteins that display sTa vs. core 2 O-glycan structures were identified by using recombinant forms of the streptococcal Siglec-like adhesins for lectin blotting and affinity capture, and the O-linked glycans were profiled by mass spectrometry. Proteoglycan 4 (PRG4), also known as lubricin, was a major carrier of sTa in the infected vegetations. Moreover, plasma PRG4 levels were significantly higher in animals with damaged or infected valves, as compared with healthy animals. The combined results demonstrate that, in addition to platelet GPIbα, PRG4 is a highly sialylated mucin-like glycoprotein found in aortic valve vegetations and may contribute to the persistence of oral streptococci in this protected endovascular niche. Moreover, plasma PRG4 could serve as a biomarker for endocardial injury and infection.

Epidemics and aetiology of hand, foot and mouth disease in Xiamen, China, from 2008 to 2015.

Over the past 8 years, human enteroviruses (HEVs) have caused 27 227 cases of hand, foot and mouth disease (HFMD) in Xiamen, including 99 severe cases and six deaths. We aimed to explore the molecular epidemiology of HFMD in Xiamen to inform the development of diagnostic assays, vaccines and other interventions. From January 2009 to September 2015, 5866 samples from sentinel hospitals were tested using nested reverse transcription PCR that targeted the HEV 5' untranslated region and viral protein 1 region. Of these samples, 4290 were tested positive for HEV and the amplicons were sequenced and genotyped. Twenty-two genotypes were identified. Enterovirus 71 (EV71) and coxsackieviruses A16, A6 and A10 (CA16, CA6 and CA10) were the most common genotypes, and there were no changes in the predominant lineages of these genotypes. EV71 became the most predominant genotype every 2 years. From 2013, CA6 replaced CA16 as one of the two most common genotypes. The results demonstrate the vast diversity of HFMD pathogens, and that minor genotypes are able to replace major genotypes. We recommend carrying-out long-term monitoring of the full spectrum of HFMD pathogens, which could facilitate epidemic prediction and the development of diagnostic assays and vaccines.

[Research progress in autophagy in the development of pulp inflammation and dental pulp injury reparation and regeneration].

Pulpitis is an infectious disease characterized by persistent inflammation of dental pulp and severe pain of patients, root canal treatment increases the risk of tooth fracture, discoloration and reinfection. Therefore, pulp injury repair and pulp regeneration become the new targets of pulpitis treatment. Autophagy is considered as an important defense and protective mechanism, thus plays an important role in preventing the host from excessive inflammatory reaction. There are few reports on the regulative mechanisms and therapeutic strategies of autophagy on pulp inflammation progression, therefore, this paper reviewed the role of autophagy on the progression of pulpitis, also reviewed the research progress of autophagy on dental pulp injury repair and regeneration, aiming to provide theoretical support for further research and clinical application.

[A multicenter prospective clinical trial on the effect of domestic bone level implants on single tooth implantation and restoration].

Objective: To evaluate the clinical application effects of a domestic bone-level implant system for restoring single tooth loss, and provide clinical evidence for the promotion and application of domestic implants. Methods: A prospective, multicenter clinical trial was conducted from April 2018 to January 2020 in three institutions: Department of Oral Implantology, School & Hospital of Stomatology, Wuhan University, Department of Stomatology, The First Affiliated Hospital of Zhejiang University School of Medicine, and Department of Stomatology, The Third Hospital of Hebei Medical University. The trial planned to include 100 patients for single tooth implantation and restoration, followed up for 1 year, to evaluate the implantation success rate and other related outcomes. Results: This study screened a total of 142 patients and ultimately included 100, comprising 43 males and 57 females with age of (47.0±12.2) years. Ninety-eight out of 100 patients completed a one-year follow-up (98.0%), while 2 patients terminated the trial early due to implant loosening (2.0%). After a one-year follow-up, the implants of the 98 patients were all functioning successfully, with a success rate of 98.0% (98/100). The patients were satisfied with the overall restoration effect. Conclusions: This study indicates that the domestic bone-level implant system has achieved favorable short-term clinical outcomes for single-tooth implantation and restoration.

[Evaluation of immediate implant in patients with limited buccal bone wall dehiscence in single upper anterior tooth].

Objective: To compare and evaluate the clinical outcome of immediate implant therapy in patients with limited buccal bone wall dehiscence and in patients with intact buccal bone wall. Methods: This prospective cohort study included patients intended to receive immediate implant treatment in upper anterior esthetic region in the Department of Implantology, Hospital of Stomatology, Wuhan University from August to December, 2018. Patients with buccal bone wall dehiscence limited to the coronal half were attributed to experimental group to conduct flap implant surgery (indicating to less than coronal half of the buccal bone wall length from the alveolar bone crest to the implant tip), whereas patients with intact buccal bone wall were attributed to control group to conduct flapless implant surgery. Buccal bone wall resorptions in height and thickness were evaluated 6 months after implant placement. Implant survival rate, pink/white esthetic score and post-operation complications were also analyzed 12 months after implant placement. Paired t-test and two-sample t-test were adopted to analyze the differences of different points within one group and differences between groups, respectively. Results: A total of 38 patients with the age of (39.2±5.8) years (range 19-45 years) and 38 upper anterior single tooth implants were included,in which 19 patients were attributed to experimental group [12 male and 7 female, the age was (37.6±5.3) years], and 19 patients were attributed to control group [9 male and 10 female, the age was (40.8±6.7) years]. Over the 12 months' observation after implant placement, the overall implant survival rate was 97% (37/38), and 18/19 in control group and 19/19 in experimental group. Only one implant lost in control group and no other complications were reported. Buccal bone resorption in thickness and height occurred in both groups within 6 months after implant placement. The thickness and height of buccal bone decreased significantly in both groups within 6 months after implant placement (P<0.05). Thickness decreases in experimental group were (1.32±0.74), (0.53±0.89) and (0.36±0.70) mm in coronal, middle and apical part of implant in experimental, and (1.24±0.57), (0.83±0.46) and (0.38±0.72) mm in coronal, middle and apical part of implant in control group. While the buccal bone height decreases were (0.24±0.15) mm in experimental group and (0.25±0.23) mm in control group. There were no statistical differences between the corresponding spots in the two groups (P>0.05). Upon the final restoration, both group got ideal pink esthetic scores [experimental group (10.92±1.13),control group (10.92±1.26)] and white esthetic scores [experimental group (7.61±0.78), control group (7.40±0.71)], the differences in both groups were not statistically significant (P>0.05). Conclusions: Clinical results of immediate implant to patients with buccal bone wall dehiscence limited to the coronal half are comparable to the results of patients with intact buccal bone wall.

Micromolar fluoride alters ameloblast lineage cells in vitro.

Fluorosed enamel is caused by exposure to fluoride during tooth formation. The objective of this study was to determine whether epithelial ameloblast-lineage cells, derived from the human enamel organ, are directly affected by micromolar concentrations of fluoride. Cells were cultured in the presence of fluoride, and proliferation was measured by BrdU incorporation. The effect of 0, 10, or 20 microM fluoride on apoptosis was determined by the flow cytometry apoptotic index. The effects of fluoride on gene expression were investigated by SuperArray microarray analysis and real-time PCR. Fluoride had a biphasic effect on cell proliferation, with enhanced proliferation at 16 microM, and reduced proliferation at greater than 1 mM F. Flow cytometry showed that both 10 microM and 20 microM NaF significantly increased the apoptotic index of ameloblast-lineage cells. There was no general effect of fluoride on gene expression. These results indicate multiple effects of micromolar fluoride on ameloblast-lineage cells.

[Complications analysis of adenoidectomy and tonsillectomy assisted with ablation on children].

Objective:To analyze the complications of adenotonsilectomy assisted with coblation in children. Method:Complications of 2 089 cases of children with adenoid and tonsil surgery assisted with coblation, in our hospital nearly 10 years, were analyzed by epidemiological methods through the method of retrospective analysis. Result:①the sex ratio of male to female was 2.08：1, average age (5.87±3.12) years old, and most of 2 089 cases 76.35% (1 595/2 089) were 3-7 years old; ②all cases underwent adenoidectomy. Different surgery methods of tonsil consisted of three groups as partial resection associated with ablation was 69.17% (1 445/2 089), ablation (channeling) alone was 22.26% (465/2 089) and total resection was 8.57% (179/208). The amount of bleeding in operation was (8.52±3.18)ml, average operation time was (30.15±8.26) minutes, the postoperative pain score was (3.77±1.61); ③The incidence of postoperative complications: postoperative bleeding (all were secondary bleeding cases) rate was 0.24% (5/2 089), recurrence rate was 0.14% (3/2 089), prevertebral lymphadenitis was 0.96% (20/2 089), the other was 0.29% (torus hyperplasia in 2 cases, dyspnea in 2 cases, 1 cases of angle of mouth burned, nasopharyngeal adhesion in 1 cases). Postoperative fever rate was 9.81% (205/2 089). Conclusion:coblation technique is a good method for the treatment of children's adenoids and tonsil diseases with high efficiency and low complications. But improving the operation procedure proficiency level and skills of operation is an important link to reduce complications.

Microcalorimetric studies on the polyhydroxyalkanoates production of recombinant Escherichia coli.

The thermogenic curves of metabolism of two strains of Escherichia coli pUC19cab/XL-IBlue and XL-IBlue have been determined by using a LKB-2277 bioActivity Monitor and ampoule method at 37 degrees C. pUC19cab/XL-IBlue was a recombinant E. coli strain bearing a foreign plasmid pUC19cab which brought the polyhydroxyalkanoates (PHAs) production. XL-IBlue was a host bacterium without any foreign DNA. Our studies reveal that the PHA production of recombinant E. coli has an apparent influence on their thermogenic curves of metabolism and therefore the initial time of PHAs production can be determined from these thermogenic curves.

Characterization of human primary enamel organ epithelial cells in vitro.

UNLABELLED: Tooth enamel is formed by ameloblasts, which are derived from the epithelial cells of the enamel organ. OBJECTIVE: The purpose of this study was to grow human ameloblast-like epithelial cells in culture. DESIGN: Human fetal tooth organs were isolated, and the cells were separated by digestion in collagenase/dispase. The cells were cultured in KGM-2 media with and without serum and at different calcium concentrations. The expression of enamel matrix proteins was analyzed by RT-PCR and cytokeratin 14 was detected by immunohistochemistry. The cells were further characterized by osteogenesis/odontogenesis-related DNA array. RESULTS: Cells isolated from the tooth organs grown in KGM-2 media containing 2-10% serum, were mixture of cobblestone and spindle shaped cells. Culturing these cells in KGM-2 with 0.05 mM calcium was selective for cobblestone ameloblasts-like cells (CAB), which were immunopositive for cytokeratin 14. Amelogenin, ameloblastin, enamelin, MMP-20 and KLK-4 were detected in CAB cells by RT-PCR. Osteogenesis SuperArray analyses could not detect the presence of typical molecules related to mesenchymal odontoblast or osteoblast lineage cells in these cultures. CONCLUSIONS: These studies showed that cobblestone-shaped ameloblast-like cells are selected from the tooth organ cells, by culture in KGM-2 media with 0.05 mM calcium.

Functional interrelationships between cell membrane and cell wall in antimicrobial peptide-mediated killing of Staphylococcus aureus.

Perturbation of the Staphylococcus aureus cytoplasmic membrane (CM) is felt to play a key role in the microbicidal mechanism of many antimicrobial peptides (APs). However, it is not established whether membrane permeabilization (MP) alone is sufficient to kill susceptible staphylococci or if the cell wall (CW) and/or intracellular targets contribute to AP-induced lethality. We hypothesized that the relationships between MP and killing may differ for distinct APs. In this study, we investigated the association between AP-induced MP and lethality in S. aureus whole cells versus CW-free protoplasts, and in comparison to the MP of liposomes modeled after whole CMs in terms of phospholipid composition, fluidity and charge. Four APs with different structure-activity relationships were examined: thrombin-induced platelet microbicidal protein 1 (tPMP-1), human neutrophil protein 1 (hNP-1), gramicidin D, and polymyxin B. MP was quantified fluorometrically by calcein release. All APs tested, except polymyxin B, caused concentration-dependent MP and killing of whole cells, but not of protoplasts. The reduced AP susceptibility of protoplasts was associated with increased cardiolipin and lysyl-phosphatidylglycerol content and reduced fluidity of their CMs. However, liposomal MP induced by tPMP-1, hNP-1, and gramicidin D paralleled that of whole cells. Collectively, these results indicate that (i) structurally distinct APs likely exert their staphylocidal effects by differing mechanisms, (ii) MP is not the sole event leading to AP-induced staphylocidal activity, (iii) a complex interrelationship exists between the CM and CW in AP-induced killing, and (iv) liposomes modeled upon whole cell or protoplast CMs can recapitulate the respective susceptibilities to killing by distinct APs.

Identification of histatins as tannin-binding proteins in human saliva.

Tannins have a number of detrimental biological effects and these include interference with normal growth and metabolism if they are present in the feed of various animals. Proline-rich proteins (PRPs) in saliva have been shown to provide protection against tannin, but little is known about the mechanism of protection and interaction of other salivary proteins with tannin. To identify tannin-binding human salivary proteins, parotid and submandibular/sublingual saliva samples were adsorbed with tannin. PRPs, and in particular a group of low-M(r) proteins, were readily precipitated by tannin. The low-M(r) proteins were purified from parotid saliva and demonstrated to be histatins, a family of well-characterized histidine-rich salivary proteins. The ability of synthetic histatin 5, as well as an acidic PRP (PRP-1) and gelatin to precipitate quebracho condensed tannin and tannic acid was determined. At pH 7.4 histatin 5 was the most effective precipitant of both condensed tannin and tannic acid and it also precipitated the largest amount of condensed tannin at pH 3.0, but the smallest amount of tannic acid at that pH. In contrast PRP-1 showed a greater ability to precipitate both condensed tannin and tannic acid at pH 3.0 than at pH 7.4. Under most circumstances histatin 5 was therefore more effective in precipitating tannins than proteins with high proline content which generally have been recognized as strong precipitants of tannin. Pre-incubation of tannic acid with alpha-amylase inhibited the enzyme, but addition of histatin 5 or the acidic PRP PIF-s protected amylase from inhibition by tannin. Similarly salivary proteins may protect other biological activities in the digestive tract from inhibition by dietary tannin.

An immunohistochemical study of the nerve growth factor receptor in developing rats.

Nerve growth factor (NGF) receptor expression was studied in rats between embryonic day 11 (E11) to postnatal day 10 (PND10) by using a monoclonal antibody, 192-IgG, that specifically recognizes rat NGF receptor. Sympathetic ganglia were lightly stained by 192-IgG for NGF receptor immunoreactivity (NGFRI) (E11-PND10). Neural crest-derived sensory ganglia were moderately to densely stained (E11-PND10). Areas in CNS innervated by the central processes of these ganglia were also stained. Parasympathetic ciliary ganglion showed some detectable staining (E16-PND6). Placode-derived sensory ganglia were stained more densely than that of neural crest-derived sensory ganglia. The most densely stained tissue for NGFRI was found in all peripheral nerves. Basal forebrain cholinergic neurons were NGFRI positive from E15 throughout the period examined. Motoneurons in both spinal cord and brain stem were positive for NGFRI between E15 and PND10. NGFRI staining was seen in a variety of sensory pathways and related structures, such as olfactory tract and glomerular layer of olfactory bulb; retina, optic nerve and tract, lateral geniculate nucleus, medial terminal nucleus of the accessory optic tract, and olivary pretectal nucleus; ventral cochlear nucleus and to a lesser degree in dorsal cochlear nucleus, superior olive, and nucleus of lateral lemniscus; solitary tract; cuneate nucleus, gracile nucleus, and ventroposterior thalamic nucleus. The specific staining was also found in some other CNS structures, including brain-stem reticular formation; amygdala; medial nucleus of inferior olive but not the rest of inferior olive, external granule cell layer and Purkinje's cells of cerebellum, and deep cerebellar nuclei. Some non-neuronal tissues such as meninges and dental tissue showed very distinctive staining. Limb buds and somites were NGFRI positive starting at E11, and the staining on muscle tissue became very dense at E15-E18 and largely disappeared around PND10. Embryonic thymus was positive for NGFRI. The adventitia surrounding blood vessels was very densely stained. The changes in NGFRI staining seen in this study suggest that NGF may have broader effects during development than previously thought.

[Progress on the biosynthesis of medium-chain-length polyhydroxyalkanoates by microorganisms].

Polyhydroxylkanoates(PHAs) are a class of polyesters produced as reserve materials by a large number of microorganisms under metabolic stress. The most fascinating feature of PHAs is its degradability, and which is supposed to take place of the traditional plastics made from petroleum in the future. PHAs are divided into two classes: short-chain-length PHAs(scl-PHAs) and medium-chain-length PHAs. mcl-PHAs is more welcome owing to its more wide crystallinity and higher extension to break than scl-PHAs, especially when some kind of new functional groups were incorporated into the side chain of the polyester. Since Psedumonas oleovorans is the most typical microorganism to produce mcl-PHAs, here the author summarized how P. oleovorans synthesize the mcl-PHAs and the production of mcl-PHAs by fermentation and give some of the idea about the future research of this field.

Dextran permeation through poly(N-isopropylacrylamide) hydrogels.

The permeation of macromolecules such as fluoroescein-labeled dextran fractions through thermally reversible hydrogels has been investigated. A permeation model has been formulated, which takes into account hydrogel porosity and tortuosity as well as the combined effect of a geometric restraint for a relatively large solute molecule at a pore entrance and the friction between solute molecules moving through the pores and pore walls. Based on this model, we have estimated the tortuosity and average pore size of a swollen hydrogel, poly(N-isopropylacrylamide) [poly(NIPAAm)] and a swollen heterogel, poly(N-isopropylacrylamide-co-vinyl-terminated dimethylsiloxane) [poly(NIPAAm-co-VTPDMS)]. The permeation data for dextran molecules up to the size of 43.5 A in radius show good agreement with the values predicted from the model.

[Clinical evaluation of ceramic inlay made by CAD/CAM for 3 year]

In this study,ceramic inlays made by CAD/CAM system were used to restore posterior tooth defects.After three years of clinical observation on 21 prostheses no secondary caries was found and patients satisfied with their restoration on aspects of color match and resistance to wear etc.Five cases of inlay fracture and of obvious space between inlay margin and Cavowall were found.The main reason was the insufficient thickness of the inlays meanwhile the selection of bonding agent was not appropriate.The clinical successful rate is 76.20%.As CAD/CAM is a sophisticated technique induced into prosthodontic area just in 1980's,it has still some deficiency to be improved and perfected.

[Stress research on support tissues of Buffer-typed conical telescopic removable denture]

In order to explore the biomechanical physiology of Buffer-typed conical telescopic removable denture restoring defected dentition with a preponderance of teeth lost and only a few remained,the authors have studied the stress distribution of the periodontal support tissue of abutments and subbasal support tissue when subjected to forced transfered from removable denture of both Buffer-typed and non Buffer-typed telescopic retainers.The results suggest that occlusal forces can be redistribute through dentures with buffer typed conical telescopic retainers which decrease forces sustained by abutments and increase the ones by subbasal support tissues thus avoiding trauma of abutments while having certain degree if physiological stimuli.We can also decrease the forces transfered to subbasal support tissues by expanding basal areas,so to alleviate the absorption of alveolar ridges.This resut is in accordance with clinical effects.

Pegylated brain-derived neurotrophic factor shows improved distribution into the spinal cord and stimulates locomotor activity and morphological changes after injury.

The neurotrophin brain-derived neurotrophic factor (BDNF) shows promise for the treatment of central nervous system (CNS) trauma and disease. Effective delivery methods are required, however, for BDNF to be useful as a therapeutic agent. To this end, we examined the penetration of intrathecally infused N-terminal pegylated BDNF (peg-BDNF) compared to similar infusion of native BDNF after spinal cord injury (SCI). Pegylation dramatically improved delivery of BDNF to the spinal cord and induced the expression of Fos in spinal cord neurons. To test whether enhanced delivery would improve the modest effects on behavioral recovery and axonal outgrowth observed with native BDNF infusion, we assessed the efficacy of 2-week 25 microg/day peg-BDNF treatment, beginning 12-24 h (early) or 15 days (delayed) after midthoracic spinal contusion. Similar to native BDNF, early treatment with peg-BDNF accelerated the recovery of stepping in the open-field and acutely stimulated locomotor central pattern generator activity, as seen by the activation of hindlimb airstepping during either period of administration. The infusion of peg-BDNF, regardless of the timing of delivery, was related to enhanced sprouting of putative cholinergic fibers, like that observed after high dose native BDNF treatment. Despite improved delivery, however, neither axonal responses nor the extent of locomotor recovery were enhanced compared to native BDNF treatment. This suggests that alternative strategies, such as neurotrophin treatment in conjunction with cell transplantation techniques, or treatment nearer the cell bodies of target neurons might be employed in an attempt to effect significant repair after SCI.

Combined treatment of acute EAE in Lewis rats with TNF-binding protein and interleukin-1 receptor antagonist.

Experimental autoimmune encephalomyelitis (EAE) is a term given to describe a collection of animal models representing the human disease multiple sclerosis (MS). Although not fully understood, the involvement of cytokines and the immune system in either EAE or human MS is well established. Past efforts have shown that inhibition of proinflammatory cytokines tumor necrosis factor (TNF-alpha) or interleukin-1 (IL-1) result in amelioration of acute EAE in Lewis rats. The present study examined this model for the effect of concomitant inhibition of both TNF-alpha and IL-1, which resulted in a modest but significant therapeutic effect that was superior to inhibition of either single agent alone with respect to four of the five variables used to follow the progression of disease in this model, i.e., clinical severity, frequency of disease, loss of body weight, and day of onset. These results are in accordance with the idea that combination treatments are likely to prove superior to single agent therapy in the treatment of autoimmune inflammatory disease.