Microbial differences between dental plaque and historic dental calculus are related to oral biofilm maturation stage

BACKGROUND

Dental calculus, calcified oral plaque biofilm, contains microbial and host biomolecules that can be used to study historic microbiome communities and host responses. Dental calculus does not typically accumulate as much today as historically, and clinical oral microbiome research studies focus primarily on living dental plaque biofilm. However, plaque and calculus reflect different conditions of the oral biofilm, and the differences in microbial characteristics between the sample types have not yet been systematically explored. Here, we compare the microbial profiles of modern dental plaque, modern dental calculus, and historic dental calculus to establish expected differences between these substrates.

RESULTS

Metagenomic data was generated from modern and historic calculus samples, and dental plaque metagenomic data was downloaded from the Human Microbiome Project. Microbial composition and functional profile were assessed. Metaproteomic data was obtained from a subset of historic calculus samples. Comparisons between microbial, protein, and metabolomic profiles revealed distinct taxonomic and metabolic functional profiles between plaque, modern calculus, and historic calculus, but not between calculus collected from healthy teeth and periodontal disease-affected teeth. Species co-exclusion was related to biofilm environment. Proteomic profiling revealed that healthy tooth samples contain low levels of bacterial virulence proteins and a robust innate immune response. Correlations between proteomic and metabolomic profiles suggest co-preservation of bacterial lipid membranes and membrane-associated proteins.

CONCLUSIONS

Overall, we find that there are systematic microbial differences between plaque and calculus related to biofilm physiology, and recognizing these differences is important for accurate data interpretation in studies comparing dental plaque and calculus.

The impact of housing type on low-income asthmatic children receiving multifaceted home interventions

OBJECTIVES

This study sought to evaluate whether government-assisted vs market-rate housing type influences the frequency of asthma symptoms or the quality of life scores among low-income urban children. In addition, the study sought to evaluate whether housing type influenced the success of in-home environmental and educational interventions in improving children's asthma symptoms or quality of life scores.

STUDY DESIGN

This was a before-and-after intervention design. Comprehensive health and environmental assessments and subsequent interventions were completed in 176 low-income households with 257 asthmatic children living in government-assisted housing and market-rate housing in Lowell, Massachusetts.

METHODS

We collected environmental and health data with questionnaires at a baseline and a 12-month follow-up visit using the Children's Health Survey for Asthma and a walk-through environmental checklist. Education, tools to remove asthma triggers from the home, and home repairs and remediation were included in the interventions.

RESULTS

As in other studies of multifaceted home interventions, there were significant improvements in all asthma symptoms, reductions in healthcare utilization related to asthma, and improvements in quality of life domains for children in both housing types. Environmental indices also improved from the baseline to the final assessment for both housing types. However, the housing type was an important factor in predicting a child's asthma status at the start of the study, with children living in government-assisted housing having significantly better physical health scores (76.8 of 100) and family emotional health scores (74.8 of 100) and fewer overnight hospital stays (mean of 0.02 in the previous 4 weeks) than children living in market-rate housing (67.6, 71.6, and 0.06, respectively). Examination of the change in the health status over the 1-year study period found that children living in market-rate housing had significantly larger reductions in the number of asthma attacks (0.43 in the previous 4 weeks versus 0.24 in assisted housing) and overnight hospital stays (0.06 in the previous 4 weeks versus 0.01 in assisted housing) and larger improvements in physical health quality of life scores (54% improved versus 25.5% in assisted housing).

CONCLUSIONS

Public assistance for low-income urban housing is associated with better health among children with asthma, and may influence the impact the in-home interventions have on health outcomes because children in market-rate housing have more prospects for improvement in their asthma-related health.

Proteomic evidence of dietary sources in ancient dental calculus

Archaeological dental calculus has emerged as a rich source of ancient biomolecules, including proteins. Previous analyses of proteins extracted from ancient dental calculus revealed the presence of the dietary milk protein β-lactoglobulin, providing direct evidence of dairy consumption in the archaeological record. However, the potential for calculus to preserve other food-related proteins has not yet been systematically explored. Here we analyse shotgun metaproteomic data from 100 archaeological dental calculus samples ranging from the Iron Age to the post-medieval period (eighth century BC to nineteenth century AD) in England, as well as 14 dental calculus samples from contemporary dental patients and recently deceased individuals, to characterize the range and extent of dietary proteins preserved in dental calculus. In addition to milk proteins, we detect proteomic evidence of foodstuffs such as cereals and plant products, as well as the digestive enzyme salivary amylase. We discuss the importance of optimized protein extraction methods, data analysis approaches and authentication strategies in the identification of dietary proteins from archaeological dental calculus. This study demonstrates that proteomic approaches can robustly identify foodstuffs in the archaeological record that are typically under-represented due to their poor macroscopic preservation.

The dental calculus metabolome in modern and historic samples

INTRODUCTION

Dental calculus is a mineralized microbial dental plaque biofilm that forms throughout life by precipitation of salivary calcium salts. Successive cycles of dental plaque growth and calcification make it an unusually well-preserved, long-term record of host-microbial interaction in the archaeological record. Recent studies have confirmed the survival of authentic ancient DNA and proteins within historic and prehistoric dental calculus, making it a promising substrate for investigating oral microbiome evolution via direct measurement and comparison of modern and ancient specimens.

OBJECTIVE

We present the first comprehensive characterization of the human dental calculus metabolome using a multi-platform approach.

METHODS

Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) quantified 285 metabolites in modern and historic (200 years old) dental calculus, including metabolites of drug and dietary origin. A subset of historic samples was additionally analyzed by high-resolution gas chromatography-MS (GC-MS) and UPLC-MS/MS for further characterization of metabolites and lipids. Metabolite profiles of modern and historic calculus were compared to identify patterns of persistence and loss.

RESULTS

Dipeptides, free amino acids, free nucleotides, and carbohydrates substantially decrease in abundance and ubiquity in archaeological samples, with some exceptions. Lipids generally persist, and saturated and mono-unsaturated medium and long chain fatty acids appear to be well-preserved, while metabolic derivatives related to oxidation and chemical degradation are found at higher levels in archaeological dental calculus than fresh samples.

CONCLUSIONS

The results of this study indicate that certain metabolite classes have higher potential for recovery over long time scales and may serve as appropriate targets for oral microbiome evolutionary studies.

Assessment of the calibration of periodontal diagnosis and treatment planning among dental students at three dental schools

Calibration in diagnosis and treatment planning is difficult to achieve due to variations that exist in clinical interpretation. To determine if dental faculty members are consistent in teaching how to diagnose and treat periodontal disease, variations among dental students can be evaluated. A previous study reported high variability in diagnoses and treatment plans of periodontal cases at Indiana University School of Dentistry. This study aimed to build on that one by extending the research to two additional schools: Marquette University School of Dentistry and West Virginia University School of Dentistry. Diagnosis and treatment planning by 40 third- and fourth-year dental students were assessed at each of the schools. Students were asked to select the diagnosis and treatment plans on a questionnaire pertaining to 11 cases. Their responses were compared using chi-square tests, and multirater kappa statistics were used to assess agreement between classes and between schools. Logistic regression models were used to evaluate the effects of school, class year, prior experience, and GPA/class rank on correct responses. One case had a statistically significant difference in responses between third- and fourth-year dental students. Kappas for school agreement and class agreement were low. The students from Indiana University had higher diagnosis and treatment agreements than the Marquette University students, and the Marquette students fared better than the West Virginia University students. This study can help restructure future periodontal courses for a better understanding of periodontal diagnosis and treatment planning.

Does Lip-Repositioning Surgery Improve Long-Term Smile Outcome and Dental Esthetics in Patients With Excessive Gingival Display? A Review of the Current Literature

Focused Clinical Question: In patients with normal crown dimensions and excessive gingival display, does lip-repositioning surgery improve long-term smile outcome and dental esthetics? Clinical Scenario: A 27-year-old systemically healthy female presents with the chief complaint of "excessive gingival display when smiling" (Fig. 1). She reports that orthodontic treatment was performed and that she was referred for orthognathic surgery to correct the maxillary vertical excess and altered passive eruption. Clinically, the patient is periodontally healthy with favorable long-term periodontal prognosis. She is unsatisfied with her smile and states that it is "compromising her self-esteem." However, she refuses to accept the orthognathic surgery because of the extensiveness and morbidity of the procedure. She inquires about alternative solutions for her esthetic problem and whether it is possible to solve her gummy smile with a less invasive procedure. Lip-repositioning and anatomic crown-lengthening surgeries are presented as treatment options. The patient decides to pursue these treatment options. Lip-repositioning surgery is performed as described by Rosenblatt and Simon¹ and Simon et al.,² and healing is uneventful. Anatomic crown lengthening is performed 6 months after the previous surgery. The patient is pleased with the reduction of the excessive gingival display after these procedures (Fig. 2). However, there is lack of clinical evidence regarding the long-term stability of this surgical procedure.

Clinical evaluation of the stain removal efficacy of a novel stannous fluoride and sodium hexametaphosphate dentifrice

PURPOSE

Recently, sodium hexametaphosphate has been introduced in dentifrice formulations to aid in the control of extrinsic stain. Two independent studies were conducted to evaluate the stain removal efficacy of a novel 0.454% stannous fluoride and sodium hexametaphosphate dentifrice (Crest Pro-Health) relative to a positive control whitening dentifrice (Colgate Total + Whitening) over a 2-week period in a subject population with pre-existing natural extrinsic stain.

METHODS

These studies were randomized, positive-controlled, parallel groups, double-blind, 2-week trials. Each study involved approximately 30 healthy adults with visible stain of the facial surfaces of the 12 anterior teeth. After baseline examination, subjects were randomly assigned to a treatment and instructed to brush unsupervised with the assigned dentifrice at least twice daily as they normally do. Efficacy was evaluated by modified Lobene examination on anterior teeth at baseline and end-of treatment (Week 2).

RESULTS

59 subjects, 29 in Study 1 and 30 in Study 2, were evaluable and included in the Week 2 analyses. Subjects ranged from 21-68 years of age. In each study, the positive control dentifrice statistically significantly (P < 0.0001) reduced stain scores following 2 weeks of brushing with median reductions of 61.9% and 94.4%. Similarly, the experimental 0.454% stannous fluoride and sodium hexametaphosphate dentifrice statistically significantly (P < 0.0001) reduced stain scores by 61.8% and 96.6% following 2 weeks of brushing. The adjusted mean changes between treatment groups did not differ significantly between the two dentifrice groups (P > 0.70 in each study). Both dentifrices were well tolerated. No subject discontinued treatment due to an adverse event.

Extrinsic stain removal efficacy of a stannous fluoride dentifrice with sodium hexametaphosphate

OBJECTIVE

Two randomized, six-week, double-blind, parallel group, clinical trials were independently conducted to compare the extrinsic stain removal efficacy of a novel whitening therapeutic dentifrice containing 0.454% stannous fluoride and sodium hexametaphosphate in a formulation with high cleaning silica, relative to a positive control whitening dentifrice.

METHODOLOGY

Generally healthy adults, 56 for study 1 and 60 for study 2, with visible extrinsic tooth stain were enrolled in the studies. At the baseline visit, stain was assessed on the facial surfaces of the eight central and lateral incisors using the modified Lobene Stain Index. Oral soft and hard tissue examinations were also conducted. In each study, subjects were randomized to either the stannous fluoride + sodium hexametaphosphate toothpaste (Crest Pro-Health) or the positive control toothpaste (Colgate Total Plus Whitening) to use twice per day for six weeks. Stain and safety were reassessed at weeks three and six.

RESULTS

Fifty-two and 58 subjects completed studies 1 and 2, respectively. In each study, there were no statistically significant differences in Lobene composite stain scores between the two treatment groups across all three visits. Both groups showed statistically significant reductions in Lobene composite stain scores at week three (p < 0.0001) and week six (p < 0.0001) relative to baseline. The percent of Lobene composite scores with a greater than 0.5 unit reduction from baseline at week six was 86% for study 1 and 97% for study 2 for the stannous fluoride + sodium hexametaphosphate dentifrice group.

CONCLUSION

Collectively, these two stain removal clinical trials demonstrate the statistically significant extrinsic stain removal efficacy for the stannous fluoride + sodium hexametaphosphate dentifrice relative to baseline. There were no statistically significant differences between the stannous fluoride + sodium hexametaphosphate dentifrice and positive control treatment group.

The venom of Bothrops asper from Guatemala: toxic activities and neutralization by antivenoms

Bothrops asper is responsible for approximately half of the snakebite envenomations in Central America. Despite its medical relevance, only the venom of Costa Rican populations of this species has been studied to some detail, and there is very little information on intraspecies variability in venom composition and toxicity. Venom of B. asper from Guatemala was analyzed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and two-dimensional gel electrophoresis, and its basic pharmacological activities were investigated with standard laboratory assays. Venom has lethal, hemorrhagic, myotoxic, edema-forming, coagulant, defibrinating and phospholipase A(2) activities, showing a similar toxicological profile to the one previously described for B. asper from Costa Rica. In addition, polyvalent antivenoms produced in Mexico and Costa Rica, and currently used in Guatemala, were tested for their ability to neutralize venom's toxic activities. Both antivenoms were effective against all effects studied, although the Costa Rican product showed higher potency against most activities tested and higher antibody titer against venom components, as determined by enzyme immunoassay. It is suggested that different dosage regimes should be considered when using these antivenoms in B. asper envenomations in Guatemala.

Quantification of human myeloperoxidase in oral fluids

Peroxidase activity in human whole saliva is derived from salivary peroxidase and myeloperoxidase. Present spectrophotometric assays are relatively non-specific and influenced by ions present in salivary secretions, resulting in an over and/or underestimation of peroxidase activities. Specific polyclonal or monoclonal antibodies would greatly simplify the identification of salivary peroxidase and myeloperoxidase in human saliva and determine the relative contribution of each enzyme to the total peroxidase activity in human saliva. In the present study, a highly purified preparation of myeloperoxidase was used to raise polyclonal antibodies against the antigen. The antibodies were purified and extensively characterized in terms of their ability to interact with the antigen, with other mammalian peroxidases, and with other proteins present in salivary fluids. The antibodies recognized only myeloperoxidase and did not cross-react with any of the substances tested, showing that these antibodies can be used to detect and differentiate myeloperoxidase from other peroxidases in saliva. We have also developed and tested a sandwich ELISA which can be used in a clinical setting to quantify myeloperoxidase in whole saliva and gingival crevicular fluid.

Isolation and characterization of a myotoxic phospholipase A2 from the venom of the arboreal snake Bothriechis (Bothrops) schlegelii from Costa Rica

A new myotoxic phospholipase A2 was isolated from the venom of the arboreal snake Bothriechis schlegelii (formerly Bothrops schlegelii) from Costa Rica, by ion-exchange chromatography on CM-Sephadex. B. schlegelii myotoxin I is a basic protein (pI > 9.3) with a subunit molecular weight of 15 kDa, which migrates as a dimer in sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions. This myotoxin is recognized by antibodies generated against Bothrops asper myotoxin II (a lysine-49 phospholipase A2), by both enzyme-immunoassay and gel immunodiffusion, in the latter case with a pattern of partial identity. The toxin induces rapid myonecrosis upon intramuscular injection in mice, as evidenced by the early increase in plasma creatine kinase activity and by direct intravital microscopic observation. B. schlegelii myotoxin I also induces edema in the mouse footpad assay and exerts lethal activity (LD50 approximately 2.5 microg/g) upon intravenous injection. The toxin has a low phospholipase A2 activity (4.2 microEq.mg-1.min-1) using egg yolk phospholipids as substrate. It also shows a weak anticoagulant effect in vitro. Its N-terminal sequence, SMYELGKMILLETGKNAATSYIAYG, shows 93% homology with both Bothrops asper myotoxin II and B. jararacussu bothropstoxin I, suggesting that B. schlegelii myotoxin I may be a new lysine-49 variant of this family of myotoxic phospholipases A2.

Increased urinary excretion of analogs of Krebs cycle metabolites and arabinose in two brothers with autistic features

A marked increase in analogs of Krebs cycle metabolites was found in the urine of two brothers with autistic features. These metabolites included citramalic, tartaric (3-OH-malic), and 3-oxoglutaric acids and compounds tentatively identified as a citric acid analog and partially identified as a phenylcarboxylic acid by the fragmentation pattern of the trimethylsilyl (TMS) derivatives of the compounds and mass shifts of the same compounds derivatized with perdeuterated N,O-bis(trimethylsilyl)trifluoroacetamide. The molecular mass of the TMS derivative of the tentatively identified citric acid analog was 596 Da, based on a finding of a significant M - 15 ion at m/z 581. The citric acid analog was excreted in quantities as high as 137 mmol/mol creatinine, based on the response factor of citric acid as a surrogate calibrator. A carbohydrate with a retention time and mass spectrum identical to arabinose was also found in high concentrations in the urine of these brothers.

Increased urinary excretion of analogs of Krebs cycle metabolites and arabinose in two brothers with autistic features

A marked increase in analogs of Krebs cycle metabolites was found in the urine of two brothers with autistic features. These metabolites included citramalic, tartaric (3-OH-malic), and 3-oxoglutaric acids and compounds tentatively identified as a citric acid analog and partially identified as a phenylcarboxylic acid by the fragmentation pattern of the trimethylsilyl (TMS) derivatives of the compounds and mass shifts of the same compounds derivatized with perdeuterated N,O-bis(trimethylsilyl)trifluoroacetamide. The molecular mass of the TMS derivative of the tentatively identified citric acid analog was 596 Da, based on a finding of a significant M - 15 ion at m/z 581. The citric acid analog was excreted in quantities as high as 137 mmol/mol creatinine, based on the response factor of citric acid as a surrogate calibrator. A carbohydrate with a retention time and mass spectrum identical to arabinose was also found in high concentrations in the urine of these brothers.

Histomorphometrical analysis of the effects of the bisphosphonate alendronate on bone loss caused by experimental periodontitis in monkeys

This study tested the efficacy of alendronate, a bisphosphate, in reducing alveolar bone loss caused by experimental periodontitis in cynomolgus monkeys. Periodontitis was initiated in adult monkeys by ligating mandibular molar teeth at the cementoenamel junction (CEJ) and subsequently inoculating the ligature with Porphyromonas (Bacteroides) gingivalis. Contralateral, homologous non-ligated teeth served as controls. Animals received, intravenously, either saline (placebo) or alendronate at 0.05 or 0.25 mg/kg every 2 weeks for 16 weeks. After the animals were sacrificed, coronal sections through mandibular molars were subjected to histomorphometrical analysis. No overt side-effects were observed in any of the animals participating in this study. In placebo-treated animals, ligation and inoculation resulted in significant bone loss both at the CEJ and at the furcation. Alendronate at 0.05 mg/kg significantly reduced bone loss associated with the experimental periodontitis at both sites. In contrast, the dose of 0.25 mg/kg was ineffective in attenuating alveolar bone loss in the furcation area and only slightly effective in preventing it at the CEJ area. The results of the histomorphometric analysis correlate closely with those of the radiographic analysis of the same experiment. These data indicate that alendronate could reduce the loss of alveolar support associated with periodontitis and suggest that bisphosphonates, by virtue of their significant inhibitory action on osteoclasts, may become a treatment modality in the battle against alveolar bone destruction during periodontal disease.

[The effect of social roles in the teacher-student relationship]

The present study aims at analysing the students and professors performance in the nursing undergraduate course of the University of São Paulo as well as learning of their own analysis about their roles. The study is based on the idea that the teaching-learning process is grounded in the interpersonal relationship between students and professors and this relationships linked to the way these individuals play their social role. The author made a qualitative analysis of four professors and four students free discourses looking at apprehending the expression of the free association of ideas as well as allowing the manifestation of the intra-psychical content of each one of them. Therefore, the author concluded that, in spite of these groups aspirations for significant changes in their roles, their behaviours reiterate former social roles based on the traditional pedagogical model.

Antibodies to ACTH in opsoclonus-myoclonus

Antibodies to ACTH1-24 detected by radioimmunoassay were present in the serum of a child with opsoclonus-myoclonus for at least 24 weeks after discontinuation of chronic ACTH treatment. The antibody-bound ACTH did not interfere with cortisol secretion. Six other children with opsoclonus-myoclonus and 16 control sera, including patients with chronically elevated endogenous ACTH, did not exhibit autoantibodies to ACTH. Antibodies to ACTH should be sought in patients who develop tolerance to ACTH treatment. The indirect but not direct ACTH assay method is sensitive to the presence of ACTH antibodies.

[Cryptococcal meningoencephalitis functioning as expansive process. Report of a case]

A case of cryptococcal meningoencephalitis occurrying in a 26-year-old white man disclosing clinical as well radiological features of a expanding process localized in the right cerebral hemisphere is reported. A definitive diagnosis was established through histopathologic examination following right fronto-temporo-parietal exploratory and decompressive craniotomy. Cryptococcus neoformans was easily demonstrated in the leptomeninges as well as in cystic spaces in the brain substance.

[Meningioma of the lateral ventricle]

É relatado um caso de meningeoma intraventricular, ocorrendo no trígono ventricular direito, em paciente do sexo feminino, com 27 anos de idade, e que foi totalmente ressecado em dois tempos cirúrgicos. O tumor pesou 400 gramas. Histologicamente, ao lado de áreas características de meningeoma endoteliomatoso, foram observados marcado pleomorfismo celular, com núcleos bizarros, e células sinciciais neoplásicas.

Retrobulbar granular cell myoblastoma

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Leiomyosarcoma in the skin. A case report

No abstract available

[Choriocarcinoma initially manifesting as a cerebral tumor]

Os autores descrevem um caso de coriocarcinoma cerebral metastático, removido cirurgicamente, ocorrendo numa paciente de 19 anos e localizado na porção posterior do lobo frontal esquerdo. Um estudo retrospectivo da paciente revelou apenas discreta perda sangüínea pelos genitais, iniciada algumas semanas após o delivramento de uma criança normal, ocorrido quatro meses antes. O exame colpocitológico da secreção cérvico-vaginal revelou uma classe V de Papanicolau (positivo para células neoplásicas malignas), tendo ulteriormente a paciente sido submetida à histerectomia total com anexectomia bilateral. Um pequeno tumor de aspecto hemorrágico-necrótico foi encontrado na cavidade uterina, tendo o exame histológico mostrado tratar-se de coriocarcinoma. Os autores tecem considerações clínico-patológicas sobre o coriocarcinoma. com especial referência às lesões metastáticas cerebrais.

Changes in media and intima of pulmonary vessels in schistosomal cor pulmonale (10 cases)

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