As an interdisciplinary of stomatology and space medicine, space oral medicine focuses mainly on oral diseases happened under space environment. With the manned space technology stepping into the new era, space oral medicine has been put under the spotlight. This article will review the historical events on this subject, summarize the newly progress especially on craniomaxillofacial bone, tooth-derived stem cell and oral microbiology researches and still put forward future prospect.
Aerospace Medicine ; Biomedical Research ; Humans ; Mouth Diseases ; Oral Medicine ; Stem Cells ; Weightlessness

OBJECTIVETo clone, express, and purify cyclic diadenosine monophosphate (c-di-AMP) metabolism-related genes from Porphyromonas gingivalis (P. gingivalis) ATCC33277.

METHODSPolymerase chain reaction (PCR) from the genome of P. gingivalis ATCC33277 amplified, the coding regions of pgn0523, pgn1187, and pgn2003 genes. The amplified DNA fragments were ligated with a prokaryotic expression vector pET28a to construct the recombinant expression plasmids pET-pgn0523, pET-pgn1187, and pET-pgn2003. These recombinant plasmids were transformed into Escherichia coli (E. coli) BL21 (DE3) competent cells. The expression of recombinant proteins was induced by isopropyl-β-D-thiogalactoside and detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Proteins were purified using a Ni²⁺ matrix column, and their concentrations were determined by a BCA Protein Quantitative Kit.

RESULTSThe c-di-AMP metabolism-related genes from P. gingivalis ATCC33277 were amplified successfully with the correct molecular size. The recombinant expression vectors were constructed by ligating enzyme-digested PCR products and pET28a vector, and verified by PCR and sequencing. After induction and purification, recombinant proteins were expressed successfully and obtained with the correct molecular size (19.5 x 10³, 39.9 x 10³, 66.0 x 10³). The final protein concentrations were 0.708, 0.523, and 0.861 mg · mL⁻¹ after dialysis.

CONCLUSIONThe c-di-AMP metabolism-related genes from P. gingivalis ATCC33277 are cloned successfully, and their coding products are expressed correctly in E. coli. High-purity proteins are finally obtained. The cloning and purification of these important proteins will help us to further investigate the physiological function and regulatory mechanism of c-di-AMP signaling system in P. gingivalis.

Bacterial Proteins ; biosynthesis ; genetics ; isolation & purification ; Cloning, Molecular ; Dinucleoside Phosphates ; Escherichia coli ; genetics ; Genetic Vectors ; Plasmids ; Polymerase Chain Reaction ; Porphyromonas gingivalis ; genetics ; Recombinant Proteins

Oral cavity and gut are important parts of the human digestive tract. The structure and pathogenesis of oral and gut microbial communities have been extensively investigated. The interaction and pathogenic effects of oral and gut microbiota have also been widely explored. This review aimed to integrate data from literature and discuss the structures and functions of microbial communities in the oral cavity and gut. The mutual colonization and pathogenesis of oral and gut microbes and the relationship between these phenomena and involved systemic diseases are also described.
Gastrointestinal Tract ; microbiology ; Humans ; Microbiota ; Mouth ; microbiology

Saliva is secreted by salivary glands and performs a variety of functions, including mouth cleaning and protection, antibacterial activity, and digestion. With the rapid progress in salivaomics, saliva became recognized as a potential pool of biological markers. Being a non-invasive and safe source, saliva is a potential substitute for blood in diagnosis and prognosis of diseases. This review summarizes the latest advancement in saliva-related studies and presents the potential value of saliva in early diagnosis of oral diseases, such as dental caries, periodontal disease, cancer, diabetes, and other systemic disorders. Saliva biomarkers can reveal changes ranging from changes in biochemical index, DNA, RNA, and proteins to the diversification of microbiota structure. By integrating recent data, this paper discusses the clinical significance and application prospect of saliva in early diagnosis of diseases and in translational and precision medicine.
Biomarkers ; Dental Caries ; Humans ; Microbiota ; Mouth Diseases ; Prognosis ; Saliva

Objective:To investigate the efficacy of treatment of bromhidrosis by cutting off the apocrine glands under direct vision combined with micro electrocoagulation.Methods:From January 2017 to December 2017, 25 patients (50 sides) with axillary osmidrosis admitted to the First People’s Hospital of Yuhang District were treated with direct vision cutting and micro electrocoagulation to destroy the apocrine sweat glands, including 13 males and 12 females, aged 14-38 years, with an average age of 23 years. According to Young-Jin Park′s criteria for judging axillary osmidrosis, 21 cases were classified as grade 3 and 4 cases as grade 2. After tumescent anesthesia, the subcutaneous apocrine sweat glands, fat and hair follicles were cut off under direct vision. The subdermal vascular network was preserved, and the basement was destroyed one by one by using high-frequency electrocoagulation mode. After the operation, the evaluation was conducted according to the criteria for judging axillary osmidrosis formulated by Young-Jin Park.Results:The symptoms of axillary osmidrosis reached the standard of cure in 24 patients after operation, 1 case failed to reach the cure standard. Among the patients who reached the standard, there were 2 cases of necrosis of the skin flap and 1 case of hematoma after operation unilaterally, which were given actively dressing change, secondary debridement, suturing and hematoma removal, The follow-up period was 6 months to 1 year. During the follow-up period, 24 cases were cured, including 21 cases of grade one and 3 cases of grade zero. The treatment effect was stable.Conclusions:The treatment of axillary osmidrosis by cutting off the apocrine sweat glands under direct vision combined with micro electrocoagulation, exposing the apocrine sweat glands as much as possible, effectively removing the apocrine sweat glands and hair follicles, and reducing the recurrence rate of axillary osmidrosis. It is a simple, safe and effective treatment technology for axillary osmidrosis.

As an interdisciplinary of stomatology and space medicine, space oral medicine focuses mainly on oral diseases happened under space environment. With the manned space technology stepping into the new era, space oral medicine has been put under the spotlight. This article will review the historical events on this subject, summarize the newly progress especially on craniomaxillofacial bone, tooth-derived stem cell and oral microbiology researches and still put forward future prospect.

Objective:To investigate the efficacy of treatment of bromhidrosis by cutting off the apocrine glands under direct vision combined with micro electrocoagulation.Methods:From January 2017 to December 2017, 25 patients (50 sides) with axillary osmidrosis admitted to the First People’s Hospital of Yuhang District were treated with direct vision cutting and micro electrocoagulation to destroy the apocrine sweat glands, including 13 males and 12 females, aged 14-38 years, with an average age of 23 years. According to Young-Jin Park′s criteria for judging axillary osmidrosis, 21 cases were classified as grade 3 and 4 cases as grade 2. After tumescent anesthesia, the subcutaneous apocrine sweat glands, fat and hair follicles were cut off under direct vision. The subdermal vascular network was preserved, and the basement was destroyed one by one by using high-frequency electrocoagulation mode. After the operation, the evaluation was conducted according to the criteria for judging axillary osmidrosis formulated by Young-Jin Park.Results:The symptoms of axillary osmidrosis reached the standard of cure in 24 patients after operation, 1 case failed to reach the cure standard. Among the patients who reached the standard, there were 2 cases of necrosis of the skin flap and 1 case of hematoma after operation unilaterally, which were given actively dressing change, secondary debridement, suturing and hematoma removal, The follow-up period was 6 months to 1 year. During the follow-up period, 24 cases were cured, including 21 cases of grade one and 3 cases of grade zero. The treatment effect was stable.Conclusions:The treatment of axillary osmidrosis by cutting off the apocrine sweat glands under direct vision combined with micro electrocoagulation, exposing the apocrine sweat glands as much as possible, effectively removing the apocrine sweat glands and hair follicles, and reducing the recurrence rate of axillary osmidrosis. It is a simple, safe and effective treatment technology for axillary osmidrosis.

The oral microecological balance is closely associated with the development of dental caries. Oxidative stress is one of the important factors regulating the composition and structure of the oral microbial community. Streptococcus mutans is closely related to the occurrence and development of dental caries. The ability of S. mutans to withstand oxidative stress affects its survival competitiveness in biofilms. The oxidative stress regulatory mechanisms of S. mutans include the synthesis of reductase, the regulation of iron and manganese uptake by metalloregulatory proteins, transcription regulator Spx, extracellular uptake of glutathione and other related signal transduction systems. The current research focuses on how S. mutans adapts to a complex external environment through an oxidative stress response and its influence on oral microecology. We can design targeted small molecular compounds for key signaling pathways to inhibit oxidative stress and weaken the virulence of S. mutans, which is important for oral microecological modulation and dental caries prevention and treatment.

Antimicrobial peptides have antibacterial effects on various pathogenic microorganisms, including natural antimicrobial peptides and synthetic antimicrobial peptides. According to the structure of natural antimicrobial peptides, synthetic antimicrobial peptides can be obtained by recombining different functional domains, adjusting the original amino acid sequence, or completely redesigning the peptides from scratch. Antimicrobial peptides can inhibit the growth of various cariogenic microorganisms and the formation of microbial biofilms. They also reduce acid production and acid resistance of microorganisms. Natural antimicrobial peptide genes can be used as genetic susceptibility markers for predicting the development of caries, thus, showing potential applications in the prevention and treatment of dental caries. The instability of natural antimicrobial peptides and the inability to achieve targeted sustained release limit their application in the prevention and treatment of oral caries. Synthetic antimicrobial peptides can enhance their stability and the antibacterial effect. Synthetic antimicrobial peptides can also be polymerized with common oral adhesives to reduce the incidence of microleakage after filling treatment for caries and to prevent the occurrence of secondary caries. The pH-sensitive antimicrobial peptides are slowly released to promote remineralization in the process of caries. However, the safety and biocompatibility of synthetic antimicrobial peptides are worse than those of natural antimicrobial peptides. Moreover, the combined effect of antibacterial peptides and anticaries drugs, such as fluoride, is still uncertain. Therefore, in this paper, we will review the design methods, application and underlying mechanisms of antimicrobial peptides to introduce novel methods and ideas for the prevention and treatment of dental caries.

Enterococcus faecalis is the main pathogen causing refractory apical periodontitis(RAP).This bacterium can tolerate harsh environments and trigger periapical immune inflammatory responses that result in persistent infection inside and outside the root canal.Adhesion to the dentin wall of root canals and the subsequent formation of biofilms significantly enhances the drug resistance and anti-erosion ability of Enterococcus faecalis,which is the key factor medi-ating its pathogenesis.The adhesion of Enterococcus faecalis to dentin involves non-specific adhesion and specific adhe-sion,and the latter is mediated by adhesion-related virulence factors,mainly including the adhesin of collagen from en-terococci(Ace),extracellular surface protein(Esp),gelatinase(GelE),serine protease(SprE),endocarditis and biofilm associated pilus(Ebp)and aggregation substance(AS),which is regulated by multiple two-component systems.The two-component system Fsr can promote the expression of gelE and sprE when the cell population density increases.GelE can further reduce Ace,while the two-component system GrvRS directly downregulates ace expression in response to the serum environment.The two-component systems CroRS and WalRK may also promote and inhibit the expression of vari-ous virulence factors,including ace and gelE,thus affecting the adhesion of Enterococcus faecalis.In addition,the mech-anochemical preparation and the internal environment of the root canal can also influence the adhesion of Enterococcus faecalis to dentin.Avoiding the introduction of Enterococcus faecalis and using adhesion-interfering medications during root canal treatment can effectively prevent the adhesion of Enterococcus faecalis,and a variety of activated irrigation protocols can also be effective at increasing the clearance of Enterococcus faecalis from the root canal.The design of ra-tional drugs targeting key factors involved in and regulators of the adhesion of Enterococcus faecalis to dentin is expected to provide new ideas and strategies for root canal infection control.The present paper reviews the adhesion of Enterococ-cus faecalis to dentin and its influencing factors.