Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 53
Filter
1.
JDR Clin Trans Res ; : 23800844231196884, 2023 Sep 25.
Article in English | MEDLINE | ID: mdl-37746735

ABSTRACT

AIMS: Brensocatib is a reversible inhibitor of dipeptidyl peptidase 1 (cathepsin C), in development to treat chronic non-cystic fibrosis bronchiectasis. The phase 2, randomized, placebo-controlled WILLOW trial (NCT03218917) was conducted to examine whether brensocatib reduced the incidence of pulmonary exacerbations. Brensocatib prolonged the time to the first exacerbation and led to fewer exacerbations than placebo. Because brensocatib potentially affects oral tissues due to its action on neutrophil-mediated inflammation, we analyzed periodontal outcomes in the trial participants. MATERIALS AND METHODS: Patients with bronchiectasis were randomized 1:1:1 to receive once-daily oral brensocatib 10 or 25 mg or placebo. Periodontal status was monitored throughout the 24-week trial in a prespecified safety analysis. Periodontal pocket depth (PPD) at screening, week 8, and week 24 was evaluated. Gingival inflammation was evaluated by a combination of assessing bleeding upon probing and monitoring the Löe-Silness Gingival Index on 3 facial surfaces and the mid-lingual surface. RESULTS: At week 24, mean ± SE PPD reductions were similar across treatment groups: -0.07 ± 0.007, -0.06 ± 0.007, and -0.15 ± 0.007 mm with brensocatib 10 mg, brensocatib 25 mg, and placebo, respectively. The distribution of changes in PPD and the number of patients with multiple increased PPD sites were similar across treatment groups at weeks 8 and 24. The frequencies of gingival index values were generally similar across treatment groups at each assessment. An increase in index values 0-1 and a decrease in index values 2-3 over time and at the end of the study were observed in all groups, indicating improved oral health. CONCLUSIONS: In patients with non-cystic fibrosis bronchiectasis, brensocatib 10 or 25 mg had an acceptable safety profile after 6 months' treatment, with no changes in periodontal status noted. Improvement in oral health at end of the study may be due to regular dental care during the trial and independent of brensocatib treatment. KNOWLEDGE TRANSFER STATEMENT: The results of this study suggest that 24 weeks of treatment with brensocatib does not affect periodontal disease progression. This information can be used by clinicians when considering treatment approaches for bronchiectasis and suggests that the use of brensocatib will not be limited by periodontal disease risks. Nevertheless, routine dental/periodontal care should be provided to patients irrespective of brensocatib treatment.

2.
Ann Ig ; 34(1): 27-44, 2022.
Article in English | MEDLINE | ID: mdl-33779676

ABSTRACT

Introduction: The Coronavirus pandemic (Covid-19) was first identified in December 2019 in the city of Wuhan, China, and later caused a severe health crisis, causing massive disruptions to most healthcare sy-stems worldwide. The Covid-19 health emergency has seen healthcare workers in the front line facing all the difficulties related to the care burden. One of the most significant and probably underinvestigated aspects is the psychological stress of the healthcare staff managing the emergency. The aim of the paper is to analyze the literature on the impact of the Covid-19 crisis on the psychological well-being of health professionals. Methodology: We conducted a systematic review of articles published on this topic during the months from January 2020 to December 2020, searching on Pub Med, Scopus and Web of Science databases. Results: Most of the issues can be summarized into five conceptual categories: Stress, Depression and Infec-tion Anxiety, Anguish, Insomnia, Post Traumatic Stress Disorder, and Suicide. The literature identifies many factors contributing to the onset of anxiety, depression, and stress, like the fear of contracting the disease and transmitting it to family members and friends, stressful shifts, and little rest among several others. The literature highlights the needs for adequate measures, including proper psychological support. Conclusion: The conducted review suggests that the behaviours of healthcare professionals during the emer-gency phase of the Covid-19 pandemic show psychological disorders that can compromise mental health. Therefore, there is a call for those in chief like hospital managers and policymakers to take action, promoting measures like surveillance, monitoring, and psychological support among others, to increase the resilience of healthcare workers, limiting stress and anxiety and allowing them to keep their performance at work.


Subject(s)
COVID-19 , Pandemics , Anxiety/epidemiology , Delivery of Health Care , Depression/epidemiology , Health Personnel , Humans , SARS-CoV-2 , Stress, Psychological/epidemiology
3.
Ann Dermatol Venereol ; 147(1): 4-8, 2020 Jan.
Article in French | MEDLINE | ID: mdl-31831215

ABSTRACT

INTRODUCTION: Living with disfiguring disorders can impair the emotional well-being and relationships of patients as well as their social and professional life. Since 2010, courses in medical cosmetic correction for disfiguring diseases have been conducted at the dermatology department of the Timone University Hospital in Marseille and they form part of an educational program. The aim of this study was to assess the satisfaction of patients taking part in this program. PATIENTS AND METHODS: This is a retrospective study of 55 patients taking part in make-up sessions from January 2010 to December 2014 and subsequently completing a questionnaire. RESULTS: The median patient age was 46 years with most being women (n=49, 89 %). They presented pigmentary disorders (54.5 %), inflammatory diseases (27.3 %) and scars (18.2 %). 75 % of patients stated that they had improved their knowledge and 82 % remarked that the technique was personalized to their needs. The technique was considered as easy by 62 % and reproducible by 87 % of patients. 55 % of patients considered that cosmetic camouflage improved their quality of life and 56 % stated that it helped them accept the gaze of others. CONCLUSION: In our study skin camouflage appears easy to use and meets patient expectations.


Subject(s)
Cosmeceuticals/therapeutic use , Patient Satisfaction , Skin Diseases/rehabilitation , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Male , Middle Aged , Pigmentation Disorders/rehabilitation , Retrospective Studies , Young Adult
4.
J Dent Res ; 97(5): 483-491, 2018 05.
Article in English | MEDLINE | ID: mdl-29328868

ABSTRACT

For decades, dental schools in the United States have endured a significant faculty shortage. Studies have determined that the top 2 sources of dental faculty are advanced education programs and private practice. Those who have completed both DDS and PhD training are considered prime candidates for dental faculty positions. However, there is no national database to track those trainees and no evidence to indicate that they entered academia upon graduation. The objective of this study was to assess outcomes of dental school-affiliated oral sciences PhD program enrollment, graduates, and placement between 1994 and 2016. Using the American Dental Association annual survey of advanced dental education programs not accredited by the Commission on Dental Accreditation and data obtained from 22 oral sciences PhD programs, we assessed student demographics, enrollment, graduation, and placement. Based on the data provided by program directors, the average new enrollment was 33, and graduation was 26 per year. A total of 605 graduated; 39 did not complete; and 168 were still in training. Among those 605 graduates, 211 were faculty in U.S. academic institutions, and 77 were faculty in foreign institutions. Given that vacant budgeted full-time faculty positions averaged 257 per year during this period, graduates from those oral sciences PhD programs who entered academia in the United States would have filled 9 (3.6%) vacant faculty positions per year. Therefore, PhD programs have consistently generated only a small pipeline of dental school faculty. Better mentoring to retain talent in academia is necessary. Stronger support and creative funding plans are essential to sustain the PhD program. Furthermore, the oral sciences PhD program database should be established and maintained by dental professional organizations to allow assessments of training models, trends of enrollment, graduation, and placement outcomes.


Subject(s)
Education, Dental, Graduate/statistics & numerical data , Humans , Schools, Dental/statistics & numerical data , Surveys and Questionnaires , United States
5.
Mol Oral Microbiol ; 32(4): 275-287, 2017 08.
Article in English | MEDLINE | ID: mdl-27448788

ABSTRACT

Periodontitis is a highly prevalent disease caused in part by an aberrant host response to the oral multi-species biofilm. A balance between the oral bacteria and host immunity is essential for oral health. Imbalances in the oral microbiome lead to an uncontrolled host inflammatory response and subsequent periodontal disease (i.e. gingivitis and periodontitis). TREM-1 is a signaling receptor present on myeloid cells capable of acting synergistically with other pattern recognition receptors leading to amplification of inflammatory responses. The aim of this study was to investigate the activation of the TREM-1 pathway in the human monocyte-like cell line THP-1 exposed to both oral pathogens and commensals. The relative expression of the genes encoding TREM-1 and its adapter protein DAP12 were determined by quantitative real-time polymerase chain reaction. The surface expression of TREM-1 was determined by flow cytometry. Soluble TREM-1 and cytokines were measured by enzyme-linked immunosorbent assay. The results demonstrate that both commensal and pathogenic oral bacteria activate the TREM-1 pathway, resulting in a proinflammatory TREM-1 activity-dependent increase in proinflammatory cytokine production.


Subject(s)
Bacteria/immunology , Bacteria/pathogenicity , Monocytes/microbiology , Periodontal Diseases/immunology , Triggering Receptor Expressed on Myeloid Cells-1/metabolism , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Cells, Cultured , Cytokines/genetics , Flow Cytometry , Humans , Immunity, Innate , Membrane Proteins/genetics , Membrane Proteins/metabolism , Periodontal Diseases/microbiology , Porphyromonas gingivalis/immunology , Porphyromonas gingivalis/pathogenicity , Real-Time Polymerase Chain Reaction , Signal Transduction , Streptococcus gordonii/immunology , Streptococcus gordonii/pathogenicity , Symbiosis , THP-1 Cells , Triggering Receptor Expressed on Myeloid Cells-1/genetics
6.
Cell Death Differ ; 22(12): 2046-57, 2015 Dec.
Article in English | MEDLINE | ID: mdl-25909889

ABSTRACT

Regulators of G protein signaling (Rgs) have pivotal roles in controlling various cellular processes, such as cell differentiation. How Rgs proteins regulate osteoclast (OC) differentiation, function and bone homeostasis is poorly understood. It was previously demonstrated that Rgs12, the largest protein in the Rgs family, is predominantly expressed in OCs and regulates OC differentiation in vitro. To further understand the role and mechanism of Rgs12 in OC differentiation and bone diseases in vivo, we created OC-targeted Rgs12 knockout mice by using inducible Mx1-Cre and CD11b-Cre. Deletion of Rgs12 in hematopoietic cells or specifically in OC precursors resulted in increased bone mass with decreased OC numbers. Loss of Rgs12 impaired OC differentiation and function with impaired Ca(2+) oscillations and reduced nuclear factor of activated T cells (NFAT) 2 expression. The introduction of wild-type osteoblasts did not rescue the defective osteoclastogenesis. Ectopic expression of NFAT2 rescued defective OC differentiation in CD11b;Rgs12(fl/fl) cells and promoted normal OC differentiation. Moreover, deletion of Rgs12 significantly inhibited pathological osteoclastogenesis and bone destruction in Rgs12-deficient mice that were subjected to ovariectomy and lipodysaccharide for bone loss. Thus our findings demonstrate that Rgs12 is an important regulator in OC differentiation and function and identify Rgs12 as a potential therapeutic target for osteoporosis and inflammation-induced bone loss.


Subject(s)
Bone Remodeling , Bone and Bones/metabolism , RGS Proteins/metabolism , Animals , Bone Marrow Cells/cytology , Bone Marrow Cells/metabolism , Bone and Bones/diagnostic imaging , Bone and Bones/pathology , CD11b Antigen/metabolism , Calcium/metabolism , Cell Differentiation/drug effects , Cells, Cultured , Femur/diagnostic imaging , Femur/metabolism , Femur/pathology , Hematopoietic Stem Cells/cytology , Hematopoietic Stem Cells/metabolism , Lipopolysaccharides/toxicity , Mice , Mice, Knockout , Mice, Transgenic , NFATC Transcription Factors/genetics , NFATC Transcription Factors/metabolism , Osteoclasts/cytology , Osteoclasts/metabolism , Osteogenesis/drug effects , RGS Proteins/deficiency , RGS Proteins/genetics , X-Ray Microtomography
7.
J Dent Res ; 93(5): 433-6, 2014 May.
Article in English | MEDLINE | ID: mdl-24736556

ABSTRACT

In 1960, the first Department of Oral Biology in the United States dedicated to the conduct of research, graduate biomedical research education, and the provision of basic oral science education for the DDS curriculum was established at the University at Buffalo. In 1963, the Department organized the first PhD Program in Oral Biology in the United States. This PhD program has produced a large cadre of oral health researchers, many of whom have gone on to make major contributions to dental research and education. This article provides a brief history of the program, the context within which the program was organized and developed, and a description of some of the many faculty, students, and fellows associated with the program. Additionally, to celebrate the 50th anniversary of this program, a symposium, entitled "The Oral Microbiome, Immunity and Chronic Disease", was held on June 12-14, 2013, in Buffalo, New York. The proceedings are published online in Advances in Dental Research (2014, Vol. 26).


Subject(s)
Biology/history , Dental Research/history , Education, Dental/history , Schools, Dental/history , Biology/education , History, 20th Century , History, 21st Century , New York
9.
Mol Oral Microbiol ; 27(5): 327-49, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22958383

ABSTRACT

Iron can regulate biofilm formation via non-coding small RNA (sRNA). To determine if iron-regulated sRNAs are involved in biofilm formation by the periodontopathogen Aggregatibacter actinomycetemcomitans, total RNA was isolated from bacteria cultured with iron supplementation or chelation. Transcriptional analysis demonstrated that the expression of four sRNA molecules (JA01-JA04) identified by bioinformatics was significantly upregulated in iron-limited medium compared with iron-rich medium. A DNA fragment encoding each sRNA promoter was able to titrate Escherichia coli ferric uptake regulator (Fur) from a Fur-repressible reporter fusion in an iron uptake regulator titration assay. Cell lysates containing recombinant AaFur shifted the mobility of sRNA-specific DNAs in a gel shift assay. Potential targets of these sRNAs, determined in silico, included genes involved in biofilm formation. The A. actinomycetemcomitans overexpressing JA03 sRNA maintained a rough phenotype on agar, but no longer adhered to uncoated polystyrene or glass, although biofilm determinant gene expression was only modestly decreased. In summary, these sRNAs have the ability to modulate biofilm formation, but their functional target genes remain to be confirmed.


Subject(s)
Aggregatibacter actinomycetemcomitans/genetics , Bacterial Proteins/metabolism , Iron/metabolism , Metalloproteins/metabolism , RNA, Bacterial/genetics , RNA, Small Untranslated/genetics , Repressor Proteins/metabolism , Trans-Activators/metabolism , Bacterial Adhesion/genetics , Bacterial Proteins/genetics , Biofilms/growth & development , Consensus Sequence/genetics , Gene Expression Regulation, Bacterial/genetics , Genes, Reporter/genetics , Humans , Mutation/genetics , Phenotype , Plasmids/genetics , Repressor Proteins/genetics , Transcription, Genetic/genetics , Up-Regulation
10.
Mol Oral Microbiol ; 27(4): 284-94, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22759313

ABSTRACT

Streptococcus gordonii is a common oral commensal bacterial species in tooth biofilm (dental plaque) and specifically binds to salivary amylase through the surface exposed amylase-binding protein A (AbpA). When S. gordonii cells are pretreated with amylase, amylase bound to AbpA facilitates growth with starch as a primary nutrition source. The goal of this study was to explore possible regulatory effects of starch, starch metabolites and amylase on the expression of S. gordonii AbpA. An amylase ligand-binding assay was used to assess the expression of AbpA in culture supernatants and on bacterial cells from S. gordonii grown in defined medium supplemented with 1% starch, 0.5 mg ml(-1) amylase, with starch and amylase together, or with various linear malto-oligosaccharides. Transcription of abpA was determined by reverse transcription quantitative polymerase chain reaction. AbpA was not detectable in culture supernatants containing either starch alone or amylase alone. In contrast, the amount of AbpA was notably increased when starch and amylase were both present in the medium. The expression of abpA was significantly increased (P < 0.05) following 40 min of incubation in defined medium supplemented with starch and amylase. Similar results were obtained in the presence of maltose and other short-chain malto-oligosacchrides. These results suggest that the products of starch hydrolysis produced from the action of salivary α-amylase, particularly maltose and maltotriose, up-regulate AbpA expression in S. gordonii.


Subject(s)
Amylases/metabolism , Bacterial Outer Membrane Proteins/genetics , Gene Expression Regulation, Enzymologic , Starch/metabolism , Streptococcus gordonii/enzymology , Bacterial Outer Membrane Proteins/biosynthesis , Enzyme Induction , Humans , Hydrolysis , Maltose/physiology , Polysaccharides/physiology , Saliva/enzymology
11.
J Dent Res ; 91(5): 513-9, 2012 May.
Article in English | MEDLINE | ID: mdl-22431892

ABSTRACT

Streptococcus gordonii and Streptococcus mutans avidly colonize teeth. S. gordonii glucosyltransferase (GtfG) and amylase-binding proteins (AbpA/AbpB), and S. mutans glucosyltransferase (GtfB), affect their respective oral colonization abilities. We investigated their interrelationships and caries association in a rat model of human caries, examining the sequence of colonization and non- vs. high-sucrose diets, the latter being associated with aggressive decay in humans and rats. Virulence-characterized wild-types of both species and well-defined mutants of S. gordonii with interrupted abpA and gtfG genes were studied. While both S. gordonii and S. mutans were abundant colonizers of rat's teeth in the presence of either diet, if inoculated singly, S. mutans always out-competed S. gordonii on the teeth, independent of diet, strain of S. mutans, simultaneous or sequential inoculation, or presence/absence of mutations of S. gordonii's abpA and gtfG genes known to negatively or positively affect its colonization and to interact in vitro with S. mutans GtfB. S. mutans out-competed S. gordonii in in vivo plaque biofilm. Caries induction reflected S. mutans or S. gordonii colonization abundance: the former highly cariogenic, the latter not. S. gordonii does not appear to be a good candidate for replacement therapy. These results are consistent with human data.


Subject(s)
Dental Caries/microbiology , Dental Plaque/microbiology , Streptococcus gordonii/physiology , Streptococcus mutans/physiology , Animals , Bacterial Outer Membrane Proteins/genetics , Bacterial Proteins/genetics , Dietary Sucrose/metabolism , Disease Models, Animal , Glucosyltransferases/genetics , Microbial Interactions/genetics , Rats , Virulence Factors/genetics
12.
Mol Oral Microbiol ; 25(2): 150-6, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20331802

ABSTRACT

A substantial proportion of the streptococcal species found in dental plaque biofilms are able to interact with the abundant salivary enzyme alpha-amylase. These streptococci produce proteins that specifically bind amylase. An important plaque species, Streptococcus mitis, secretes a 36-kDa amylase-binding protein into the extracellular milieu. Proteins precipitated from S. mitis NS51 cell culture supernatant by the addition of purified salivary amylase were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to a membrane, and a prominent 36-kDa band was cut from the membrane and sequenced to yield the N-terminal amino acid sequence DSQAQYSNGV. Searching the S. mitis genome sequence database revealed a single open reading frame containing this sequence, and the gene was amplified by the S. mitis genomic DNA polymerase chain reaction. The coding region of this open reading frame, designated amylase-binding protein C (AbpC), was cloned into an Escherichia coli expression vector and the recombinant AbpC (rAbpC) was purified from the soluble fraction of the E. coli cell lysate. Purified AbpC was found to interact with immobilized amylase, confirming AbpC as a new streptococcal amylase-binding protein.


Subject(s)
Bacterial Outer Membrane Proteins/genetics , Bacterial Outer Membrane Proteins/isolation & purification , Streptococcus mitis/enzymology , alpha-Amylases/metabolism , Amino Acid Sequence , DNA, Bacterial/analysis , Dental Plaque/microbiology , Electrophoresis, Polyacrylamide Gel , Escherichia coli/metabolism , Humans , Protein Binding , Recombinant Proteins/isolation & purification , Saliva/microbiology , Streptococcus mitis/genetics , Transfection
13.
Arch Oral Biol ; 53(2): 133-40, 2008 Feb.
Article in English | MEDLINE | ID: mdl-17961499

ABSTRACT

OBJECTIVE: Extracellular glucan synthesis from sucrose by Streptococcus gordonii, a major dental plaque biofilm bacterium, is assumed important for colonization of teeth; but this hypothesis is un-tested in vivo. METHODS: To do so, we studied an isogenic glucosyltransferase (Gtf)-negative mutant (strain AMS12, gtfG(-)) of S. gordonii sequenced wild type (WT, strain Challis CH1, gtfG(+)), comparing their in vitro abilities to grow in the presence of glucose and sucrose and, in vivo, to colonize and persist on teeth and induce caries in rats. Weanling rats of two breeding colonies, TAN:SPFOM(OM)BR and TAN:SPFOM(OMASF)BR, eating high sucrose diet, were inoculated with either the WT (gtfG(+)), its isogenic gtfG(-) mutant, or reference strains of Streptococcus mutans. Control animals were not inoculated. RESULTS: In vitro, the gtfG(-) strain grew at least as rapidly in the presence of sucrose as its WT gtfG(+) progenitor, but formed soft colonies on sucrose agar, consistent with its lack of insoluble glucan synthesis. It also had a higher growth yield due apparently to its inability to channel carbon flow into extracellular glucan. In vivo, the gtfG(-) mutant initially colonized as did the WT but, unlike the WT, failed to persist on the teeth as shown over time. By comparison to three S. mutans strains, S. gordonii WT, despite its comparable ecological success on the teeth, was associated with only modest caries induction. Failure of the gtfG(-) mutant to persistently colonize was associated with slight diminution of caries scores by comparison with its gtfG(+) WT. CONCLUSIONS: Initial S. gordonii colonization does not depend on Gtf-G synthesis; rather, Gtf-G production determines S. gordonii's ability to persist on the teeth of sucrose-fed rats. S. gordonii appears weakly cariogenic by comparison with S. mutans reference strains.


Subject(s)
Bacterial Adhesion/physiology , Bacterial Proteins/physiology , Dental Plaque/metabolism , Glucosyltransferases/metabolism , Streptococcus gordonii/enzymology , Animals , Biofilms/growth & development , Dental Caries/enzymology , Dental Caries/microbiology , Dental Plaque/microbiology , Glucosyltransferases/genetics , Rats , Streptococcus gordonii/growth & development , Sucrose/administration & dosage , Tooth
14.
Oral Dis ; 13(6): 508-12, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17944664

ABSTRACT

Bacteria from the oral biofilms may be aspirated into the respiratory tract to influence the initiation and progression of systemic infectious conditions such as pneumonia. Oral bacteria, poor oral hygiene, and periodontitis seem to influence the incidence of pulmonary infections, especially nosocomial pneumonia episodes in high-risk subjects. Improved oral hygiene has been shown to reduce the occurrence of nosocomial pneumonia, both in mechanically-ventilated hospital patients and non-ventilated nursing home residents. It appears that oral colonization by potential respiratory pathogens, possibly fostered by periodontitis, and possibly by bacteria specific to the oral cavity or to periodontal diseases contribute to pulmonary infections. Thus, oral hygiene will assume an even more important role in the care of high-risk subjects--patients in the hospital intensive care and the elderly. The present paper critically reviews the recent literature on the effect of oral biofilms and periodontitis on pneumonia.


Subject(s)
Biofilms , Dental Plaque/complications , Oral Hygiene , Periodontitis/complications , Pneumonia, Bacterial/microbiology , Dental Plaque/microbiology , Humans , Institutionalization , Periodontitis/microbiology , Pneumonia, Bacterial/prevention & control
15.
Ann N Y Acad Sci ; 1098: 496-7, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17435158

ABSTRACT

A longitudinal case-control study was performed to measure the association of salivary biomarkers with alveolar bone loss from a sub-sample of 1,256 post-menopausal women enrolled in the Buffalo Women's Health Initiative. From this cohort, 40 subjects with significant alveolar bone loss over a 5-year period were compared to 40 age-matched control subjects having no alveolar bone loss. Several biomarkers were quantitated in saliva collected at baseline by immunoassay. A positive association was noted between alveolar bone loss and salivary concentrations of hepatocyte growth factor, and interleukin-1 beta, while a negative association was noted for alveolar bone loss and salivary osteonectin. This study provides preliminary evidence that several salivary biomarkers measured at baseline may serve to predict future alveolar bone loss.


Subject(s)
Alveolar Bone Loss/metabolism , Saliva/metabolism , Biomarkers/analysis , Case-Control Studies , Female , Hepatocyte Growth Factor/analysis , Humans , Interleukin-1beta/analysis , Longitudinal Studies , Osteonectin/analysis , Risk Factors , Saliva/chemistry
16.
Microbiology (Reading) ; 149(Pt 9): 2653-2660, 2003 Sep.
Article in English | MEDLINE | ID: mdl-12949189

ABSTRACT

Streptococcus gordonii produces two alpha-amylase-binding proteins, AbpA and AbpB, that have been extensively studied in vitro. Little is known, however, about their significance in oral colonization and cariogenicity (virulence). To clarify these issues, weanling specific pathogen-free Osborne-Mendel rats, TAN : SPFOM(OM)BR, were inoculated either with wild-type strains FAS4-S or Challis-S or with strains having isogenic mutations of abpA, abpB, or both, to compare their colonization abilities and persistence on the teeth. Experiments were done with rats fed a sucrose-rich diet containing low amounts of starch or containing only starch. The mutants and wild-types were quantified in vivo and carious lesions were scored. In 11 experiments, S. gordonii was a prolific colonizer of the teeth when rats were fed the sucrose (with low starch)-supplemented diet, often dominating the flora. Sucrose-fed rats had several-fold higher recoveries of inoculants than those eating the sucrose-free, starch-supplemented diet, regardless of inoculant type. The strain defective in AbpB could not colonize teeth of starch-only-eating rats, but could colonize rats if sucrose was added to the diet. Strains defective in AbpA surprisingly colonized better than their wild-types. A double mutant deficient in both AbpA and AbpB (abpA/abpB) colonized like its wild-type. Wild-types FAS4-S and Challis-S had no more than marginal cariogenicity. Notably, in the absence of AbpA, cariogenicity was slightly augmented. Both the rescue of colonization by the AbpB- mutant and the augmentation of colonization by AbpA- mutant in the presence of dietary sucrose suggested additional amylase-binding protein interactions relevant to colonization. Glucosyltransferase activity was greater in mutants defective in abpA and modestly increased in the abpB mutant. It was concluded that AbpB is required for colonization of teeth of starch-eating rats and its deletion is partially masked if rats eat a sucrose-starch diet. AbpA appears to inhibit colonization of the plaque biofilm in vivo. This unexpected effect in vivo may be associated with interaction of AbpA with glucosyltransferase or with other colonization factors of these cells. These data illustrate that the complex nature of the oral environment may not be adequately modelled by in vitro systems.


Subject(s)
Bacterial Adhesion/physiology , Bacterial Proteins/physiology , Biofilms/growth & development , Carrier Proteins/physiology , Streptococcus/growth & development , Tooth/microbiology , Animals , Bacterial Outer Membrane Proteins , Dental Caries/microbiology , Glucosyltransferases/metabolism , Protein Binding , Rats , Rats, Inbred Strains/microbiology , Streptococcus/genetics , Streptococcus/physiology
17.
Infect Immun ; 69(11): 7046-56, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11598080

ABSTRACT

Interactions between bacteria and salivary components are thought to be important in the establishment and ecology of the oral microflora. alpha-Amylase, the predominant salivary enzyme in humans, binds to Streptococcus gordonii, a primary colonizer of the tooth. Previous studies have implicated this interaction in adhesion of the bacteria to salivary pellicles, catabolism of dietary starches, and biofilm formation. Amylase binding is mediated at least in part by the amylase-binding protein A (AbpA). To study the function of this protein, an erythromycin resistance determinant [erm(AM)] was inserted within the abpA gene of S. gordonii strains Challis and FAS4 by allelic exchange, resulting in abpA mutant strains Challis-E1 and FAS4-E1. Comparison of the wild-type and mutant strains did not reveal any significant differences in colony morphology, biochemical metabolic profiles, growth in complex or defined media, surface hydrophobicity, or coaggregation properties. Scatchard analysis of adhesion isotherms demonstrated that the wild-type strains adhered better to human parotid-saliva- and amylase-coated hydroxyapatite than did the AbpA mutants. In contrast, the mutant strains bound to whole-saliva-coated hydroxyapatite to a greater extent than did the wild-type strains. While the wild-type strains preincubated with purified salivary amylase grew well in defined medium with potato starch as the sole carbohydrate source, the AbpA mutants did not grow under the same conditions even after preincubation with amylase. In addition, the wild-type strain produced large microcolonies in a flow cell biofilm model, while the abpA mutant strains grew much more poorly and produced relatively small microcolonies. Taken together, these results suggest that AbpA of S. gordonii functions as an adhesin to amylase-coated hydroxyapatite, in salivary-amylase-mediated catabolism of dietary starches and in human saliva-supported biofilm formation by S. gordonii.


Subject(s)
Adhesins, Bacterial/physiology , Bacterial Adhesion/physiology , Bacterial Proteins , Biocompatible Materials/metabolism , Biofilms/growth & development , Carrier Proteins/physiology , Durapatite/metabolism , Starch/metabolism , Streptococcus/physiology , alpha-Amylases/metabolism , Adhesins, Bacterial/genetics , Adhesins, Bacterial/metabolism , Bacterial Outer Membrane Proteins , Carrier Proteins/genetics , Carrier Proteins/metabolism , Humans , Mutagenesis, Insertional , Streptococcus/growth & development , Streptococcus/isolation & purification , Streptococcus/metabolism
18.
J Bacteriol ; 183(11): 3521-5, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11344161

ABSTRACT

The amylase-binding protein A (AbpA) of Streptococcus gordonii was found to be undetectable in supernatants of mid-log-phase cultures containing >1% glucose but abundant in supernatants of cultures made with brain heart infusion (BHI), which contains 0.2% glucose. A 10-fold decrease in the level of abpA mRNA in S. gordonii cells cultured in BHI was noted after the addition of glucose to 1%. Analysis of the abpA sequence revealed a potential catabolite responsive element CRE 153 bp downstream of the putative translational start site. A catabolite control protein A gene (ccpA) homolog from S. gordonii, designated regG, was cloned. A regG mutant strain demonstrated moderately less repression of abpA transcription in the presence of 1% glucose. Diauxic growth with glucose and lactose was not affected in the RegG mutant compared to the wild-type parental strain. These results suggest that while RegG plays a role in abpA expression, other mechanisms of catabolite repression are present.


Subject(s)
Bacterial Proteins/metabolism , Carrier Proteins/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Bacterial/genetics , Repressor Proteins/genetics , Repressor Proteins/metabolism , Streptococcus/genetics , Amino Acid Sequence , Bacterial Outer Membrane Proteins , Bacterial Proteins/genetics , Base Sequence , Carbohydrate Metabolism , Carrier Proteins/genetics , Culture Media , DNA-Binding Proteins/chemistry , Molecular Sequence Data , Repressor Proteins/chemistry , Sequence Analysis, DNA , Sequence Homology , Streptococcus/growth & development , Streptococcus/metabolism , Transcription, Genetic
19.
Arch Oral Biol ; 46(4): 323-33, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11269866

ABSTRACT

The significance of Streptococcus gordonii in dental caries is undefined, as is that of other alpha-amylase-binding bacteria (ABB) commonly found in the mouth. To clarify the ecological and cariological roles of S. gordonii our specific pathogen-free Osborne-Mendel rats, TAN:SPFOM(OM)BR, were fed either diet 2000 (containing 56% confectioner's sugar, most of which is sucrose) or diet 2000CS (containing 56% cornstarch, in lieu of confectioner's sugar) and inoculated with S. gordonii strains. Uninoculated rats were free of both indigenous mutans streptococci (MS) and ABB, including S. gordonii, as shown by culture on mitis salivarius and blood agars of swabs and sonicates of dentitions after weanlings had consumed these diets for 26 days. ABB were detected by radiochemical assay using [125I]-amylase reactive to alpha-amylase-binding protein characteristic of the surface of S. gordonii and other ABB. No ABB were detected (detection limit < 1 colony-forming units in 10(6) colony-forming units). Thus the TAN:SPFOM(OM)BR colony presents a 'clean animal model' for subsequent study. Consequently, S. gordonii strains Challis or G9B were used to inoculate weanling rat groups consuming either the high-sucrose diet 2000 or the cornstarch diet 2000CS. Two additional groups fed each of these diets remained unioculated. Recoveries of inoculants were tested 12 and 26 days later by oral swabs and sonication of the molars of one hemimandible of each animal, respectively. Uninoculated animals were reconfirmed to be free of ABB and mutans streptococci, but inoculated ones eating diet 2000CS had S. gordonii recoveries of 1-10% or, if eating diet 2000, 10-30% of total colony-farming units in sonicates. There were no statistically significant differences among the inoculated and uninoculated animal groups' caries scores when they ate the cornstarch diet. Lesion scores for sucrose-eating rats were, however, from 2.4-5.1-fold higher than for cornstarch-eating rats, P < 0.001, and were still higher if animals had been inoculated with either Challis (1.41-fold) or G9B (1.64-fold), than if uninoculated, both P < 0.001, so long as the rats ate the sucrose diet. Therefore, TAN:SPFOM(OM)BR rats do not harbour ABB or S. gordonii but can be colonized by S. gordonii. Colonization levels of S. gordonii on the teeth are higher in the presence of high sucrose than with high starch-containing diets. Caries scores are augmented by sucrose compared with starch, and are further augmented by S gordonii colonization. S. gordonii is thus cariologically significant in the presence of sucrose, at least in this rat.


Subject(s)
Dental Caries/microbiology , Disease Models, Animal , Rats, Inbred Strains/microbiology , Streptococcus sanguis/enzymology , Streptococcus sanguis/pathogenicity , Amylases/metabolism , Analysis of Variance , Animal Feed , Animals , Dietary Sucrose/metabolism , Mouth/microbiology , Protein Binding , Rats , Specific Pathogen-Free Organisms , Starch/metabolism , Statistics, Nonparametric , Virulence
20.
J Periodontol ; 72(1): 50-6, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11210073

ABSTRACT

BACKGROUND: Associations between poor oral health and chronic lung disease have recently been reported. The present study evaluated these potential associations by analyzing data from the National Health and Nutrition Examination Survey III (NHANES III), which documents the general health and nutritional status of randomly selected United States subjects from 1988 to 1994. METHODS: This cross-sectional, retrospective study of the NHANES III database included a study population of 13,792 subjects > or = 20 years of age with at least 6 natural teeth. A history of bronchitis and/or emphysema was recorded from the medical questionnaire, and a dichotomized variable combined those with either chronic bronchitis and/or emphysema, together considered as chronic obstructive pulmonary disease (COPD). Subject lung function was estimated by calculating the ratio of forced expiratory volume (FEV) after 1 second (FEV1)/forced vital capacity (FVC). Oral health status was assessed from the DMFS/T index (summary of cumulative caries experience), gingival bleeding, gingival recession, gingival probing depth, and periodontal attachment level. Unweighted analyses were used for initial examination of the data, and a weighted analysis was performed in a final logistic regression model adjusting for age, gender, race and ethnicity, education, income, frequency of dental visits, diabetes mellitus, smoking, and alcohol use. RESULTS: The mean age of all subjects was 44.4 +/- 17.8 years (mean +/- SD): COPD = 51.2 +/- 17.9 years and subjects without COPD = 43.9 +/- 17.7 years. Subjects with a history of COPD had more periodontal attachment loss than subjects without COPD (1.48 +/- 1.35 mm versus 1.17 +/- 1.09 mm, P = 0.0001). Subjects with mean attachment loss (MAL) > or = 3.0 mm had a higher risk of COPD than those having MAL < 3.0 mm (odds ratio, 1.45; 95% CI, 1.02 to 2.05). A trend was noted in that lung function appeared to diminish with increasing periodontal attachment loss. CONCLUSIONS: The findings of the present analysis support recently published reports that suggest an association between periodontal disease and COPD.


Subject(s)
Lung Diseases, Obstructive/epidemiology , Periodontal Diseases/epidemiology , Adult , Age Factors , Alcohol Drinking/epidemiology , Bronchitis/epidemiology , Cross-Sectional Studies , DMF Index , Diabetes Mellitus/epidemiology , Educational Status , Ethnicity/statistics & numerical data , Female , Forced Expiratory Volume/physiology , Gingival Hemorrhage/epidemiology , Gingival Pocket/epidemiology , Gingival Recession/epidemiology , Humans , Income , Logistic Models , Male , Middle Aged , Odds Ratio , Periodontal Attachment Loss/epidemiology , Pulmonary Emphysema/epidemiology , Racial Groups , Retrospective Studies , Sex Factors , Smoking/epidemiology , United States/epidemiology , Vital Capacity/physiology
SELECTION OF CITATIONS
SEARCH DETAIL
...