Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate(BP)-related osteonecrosis of the jaw(ONJ) or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bacteri...Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate(BP)-related osteonecrosis of the jaw(ONJ) or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bacteria, most of these difficult to cultivate and presents many clinical challenges. The purpose of this study was to characterize the bacterial diversity in BRONJ lesions and to determine host immune response. We examined tissue specimens from three cohorts(n530); patients with periodontal disease without a history of BP therapy(Control, n510), patients with periodontal disease having history of BP therapy but without ONJ(BP, n55) and patients with BRONJ(BRONJ, n515). Denaturing gradient gel electrophoresis of polymerase chain reaction(PCR)-amplified 16 S r RNA gene fragments revealed less bacterial diversity in BRONJ than BP and Control cohorts. Sequence analysis detected six phyla with predominant affiliation to Firmicutes in BRONJ(71.6%), BP(70.3%) and Control(59.1%). Significant differences(P,0.05) in genera were observed, between Control/BP, Control/BRONJ and BP/BRONJ cohorts. Enzyme-linked immunosorbent assay(ELISA)results indicated that the levels of myeloperoxidase were significantly lower, whereas interleukin-6 and tumor necrosis factor-alpha levels were moderately elevated in BRONJ patients as compared to Controls. PCR array showed significant changes in BRONJ patients with downregulation of host genes, such as nucleotide-binding oligomerization domain containing protein 2, and cathepsin G, the key modulators for antibacterial response and upregulation of secretory leukocyte protease inhibitor, proteinase 3 and conserved helix–loop–helix ubiquitous kinase. The results suggest that colonization of unique bacterial communities coupled with deficient innate immune response is likely to impact the pathogenesis of ONJ.展开更多
The Encouraging Novel Amelogenesis Models and Ex vivo cell Lines(ENAMEL) Development workshop was held on 23 June 2017 at the Bethesda headquarters of the National Institute of Dental and Craniofacial Research(NIDCR)....The Encouraging Novel Amelogenesis Models and Ex vivo cell Lines(ENAMEL) Development workshop was held on 23 June 2017 at the Bethesda headquarters of the National Institute of Dental and Craniofacial Research(NIDCR). Discussion topics included model organisms, stem cells/cell lines, and tissues/3 D cell culture/organoids. Scientists from a number of disciplines,representing institutions from across the United States, gathered to discuss advances in our understanding of enamel, as well as future directions for the field.展开更多
Lactobacilli have been consistently associated with dental caries for decades;however, knowledge of this group of bacteria in the etiology of the disease is limited to quantitative elucidation. Nowadays, explicit iden...Lactobacilli have been consistently associated with dental caries for decades;however, knowledge of this group of bacteria in the etiology of the disease is limited to quantitative elucidation. Nowadays, explicit identification of oral Lactobacillus species is possible, despite their taxonomic complexity. Here we describe a combined approach involving both cultivation and genetic methods to ascertain and characterize the diversity and abundance of the Lactobacillus population in the oral cavities of children with severe early childhood caries (S-ECC). Eighty 3- to 6-year-old children (40 S-ECC and 40 caries free) who were seeking dental care at the Pediatric Dental Clinic of Bellevue Hospital in New York City were invited to participate in this study. Clinical data on sociodemographic information and oral health behavior were obtained from the primary caregiver. The data included a detailed dental examination, children’s medical history, and a questionnaire survey. Combined non-stimulated saliva and supragingival plaque samples were collected from each child and cultivated on selective media for quantitative measures of lactobacilli levels. The procedure for Lactobacillus species screening will include the random selection of 50 colonies per plate, ex- traction of DNA from each colony, and genotyping by arbitrarily primed polymerase chain reaction (AP-PCR). Each unique Lactobacillus AP-PCR genotype will be selected for taxonomic assessment by 16S rRNA gene sequencing analysis. Lactobacillus species will be identified by comparing the 16S rRNA sequences with the Ribosomal Database and the Human Oral Microbiome Database. Meanwhile, the same set of clinical samples will be independently subjected to genomic DNA isolation, 16S rRNA amplification with Lactobacillus genus-specific primers, sequencing, and taxonomic identification, both at genus and species levels with a customized pipeline. The distribution and phylogenetic differences of these Lactobacillus species will be compared between children with or without S-ECC. One of the main objectives of this study is to establish a study protocol for the identification and characterization of lactobacilli in the oral cavity. Future caries risk assessments can include lactobacilli counts (quantitative) and the presence/absence of specific cario- genic genetic signatures of a Lactobacillus species (qualitative) associated with S-ECC.展开更多
Diabetes mellitus is an enormous menace to public health globally.This chronic disease of metabolism will adversely affect the skeleton if not controlled.Both type 1 diabetes mellitus(T1DM)and type 2 diabetes mellitus...Diabetes mellitus is an enormous menace to public health globally.This chronic disease of metabolism will adversely affect the skeleton if not controlled.Both type 1 diabetes mellitus(T1DM)and type 2 diabetes mellitus(T2DM)are associated with an increased risk of osteoporosis and fragility fractures.Bone mineral density is reduced in T1DM,whereas patients with T2DM have normal or slightly higher bone density,suggesting impaired bone quality is involved.Detrimental effects of T1DM on the skeleton are more severe than T2DM,probably because of the lack of osteo-anabolic effects of insulin and other pancreatic hormones.In both T1DM and T2DM,low bone quality could be caused by various means,including but not limited to hyperglycemia,accumulation of advanced glycosylation end products(AGEs),decreased serum levels of osteocalcin and parathyroid hormone.Risk for osteoarthritis is also elevated in diabetic population.How diabetes accelerates the deterioration of cartilage remains largely unknown.Hyperglycemia and glucose derived AGEs could contribute to the development of osteoarthritis.Moreover,it is recognized that oral antidiabetic medicines affect bone metabolism and turnover as well.Insulin is shown to have anabolic effects on bone and hyperinsulinemia may help to explain the slightly higher bone density in patients with T2DM.Thiazolidinediones can promote bone loss and osteoporotic fractures by suppressing osteoblastogenesis and enhancing osteoclastogenesis.Metformin favors bone formation by stimulating osteoblast differentiation and protecting them against diabetic conditions such as hyperglycemia.Better knowledge of how diabetic conditions and its treatments influence skeletal tissues is in great need in view of the growing and aging population of patients with diabetes mellitus.展开更多
基金supported by NIH grants CA172894, CA180277, DE020891New York University Research Funds
文摘Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate(BP)-related osteonecrosis of the jaw(ONJ) or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bacteria, most of these difficult to cultivate and presents many clinical challenges. The purpose of this study was to characterize the bacterial diversity in BRONJ lesions and to determine host immune response. We examined tissue specimens from three cohorts(n530); patients with periodontal disease without a history of BP therapy(Control, n510), patients with periodontal disease having history of BP therapy but without ONJ(BP, n55) and patients with BRONJ(BRONJ, n515). Denaturing gradient gel electrophoresis of polymerase chain reaction(PCR)-amplified 16 S r RNA gene fragments revealed less bacterial diversity in BRONJ than BP and Control cohorts. Sequence analysis detected six phyla with predominant affiliation to Firmicutes in BRONJ(71.6%), BP(70.3%) and Control(59.1%). Significant differences(P,0.05) in genera were observed, between Control/BP, Control/BRONJ and BP/BRONJ cohorts. Enzyme-linked immunosorbent assay(ELISA)results indicated that the levels of myeloperoxidase were significantly lower, whereas interleukin-6 and tumor necrosis factor-alpha levels were moderately elevated in BRONJ patients as compared to Controls. PCR array showed significant changes in BRONJ patients with downregulation of host genes, such as nucleotide-binding oligomerization domain containing protein 2, and cathepsin G, the key modulators for antibacterial response and upregulation of secretory leukocyte protease inhibitor, proteinase 3 and conserved helix–loop–helix ubiquitous kinase. The results suggest that colonization of unique bacterial communities coupled with deficient innate immune response is likely to impact the pathogenesis of ONJ.
文摘The Encouraging Novel Amelogenesis Models and Ex vivo cell Lines(ENAMEL) Development workshop was held on 23 June 2017 at the Bethesda headquarters of the National Institute of Dental and Craniofacial Research(NIDCR). Discussion topics included model organisms, stem cells/cell lines, and tissues/3 D cell culture/organoids. Scientists from a number of disciplines,representing institutions from across the United States, gathered to discuss advances in our understanding of enamel, as well as future directions for the field.
基金supported by the National Institute of Dental and Craniofacial Research(R01DE019455).
文摘Lactobacilli have been consistently associated with dental caries for decades;however, knowledge of this group of bacteria in the etiology of the disease is limited to quantitative elucidation. Nowadays, explicit identification of oral Lactobacillus species is possible, despite their taxonomic complexity. Here we describe a combined approach involving both cultivation and genetic methods to ascertain and characterize the diversity and abundance of the Lactobacillus population in the oral cavities of children with severe early childhood caries (S-ECC). Eighty 3- to 6-year-old children (40 S-ECC and 40 caries free) who were seeking dental care at the Pediatric Dental Clinic of Bellevue Hospital in New York City were invited to participate in this study. Clinical data on sociodemographic information and oral health behavior were obtained from the primary caregiver. The data included a detailed dental examination, children’s medical history, and a questionnaire survey. Combined non-stimulated saliva and supragingival plaque samples were collected from each child and cultivated on selective media for quantitative measures of lactobacilli levels. The procedure for Lactobacillus species screening will include the random selection of 50 colonies per plate, ex- traction of DNA from each colony, and genotyping by arbitrarily primed polymerase chain reaction (AP-PCR). Each unique Lactobacillus AP-PCR genotype will be selected for taxonomic assessment by 16S rRNA gene sequencing analysis. Lactobacillus species will be identified by comparing the 16S rRNA sequences with the Ribosomal Database and the Human Oral Microbiome Database. Meanwhile, the same set of clinical samples will be independently subjected to genomic DNA isolation, 16S rRNA amplification with Lactobacillus genus-specific primers, sequencing, and taxonomic identification, both at genus and species levels with a customized pipeline. The distribution and phylogenetic differences of these Lactobacillus species will be compared between children with or without S-ECC. One of the main objectives of this study is to establish a study protocol for the identification and characterization of lactobacilli in the oral cavity. Future caries risk assessments can include lactobacilli counts (quantitative) and the presence/absence of specific cario- genic genetic signatures of a Lactobacillus species (qualitative) associated with S-ECC.
文摘Diabetes mellitus is an enormous menace to public health globally.This chronic disease of metabolism will adversely affect the skeleton if not controlled.Both type 1 diabetes mellitus(T1DM)and type 2 diabetes mellitus(T2DM)are associated with an increased risk of osteoporosis and fragility fractures.Bone mineral density is reduced in T1DM,whereas patients with T2DM have normal or slightly higher bone density,suggesting impaired bone quality is involved.Detrimental effects of T1DM on the skeleton are more severe than T2DM,probably because of the lack of osteo-anabolic effects of insulin and other pancreatic hormones.In both T1DM and T2DM,low bone quality could be caused by various means,including but not limited to hyperglycemia,accumulation of advanced glycosylation end products(AGEs),decreased serum levels of osteocalcin and parathyroid hormone.Risk for osteoarthritis is also elevated in diabetic population.How diabetes accelerates the deterioration of cartilage remains largely unknown.Hyperglycemia and glucose derived AGEs could contribute to the development of osteoarthritis.Moreover,it is recognized that oral antidiabetic medicines affect bone metabolism and turnover as well.Insulin is shown to have anabolic effects on bone and hyperinsulinemia may help to explain the slightly higher bone density in patients with T2DM.Thiazolidinediones can promote bone loss and osteoporotic fractures by suppressing osteoblastogenesis and enhancing osteoclastogenesis.Metformin favors bone formation by stimulating osteoblast differentiation and protecting them against diabetic conditions such as hyperglycemia.Better knowledge of how diabetic conditions and its treatments influence skeletal tissues is in great need in view of the growing and aging population of patients with diabetes mellitus.
