Role of the Yersinia pestis phospholipase D (Ymt) in the initial aggregation step of biofilm formation in the flea.

Transmission of Yersinia pestis by fleas depends on the formation of condensed bacterial aggregates embedded within a gel-like matrix that localizes to the proventricular valve in the flea foregut and interferes with normal blood feeding. This is essentially a bacterial biofilm phenomenon, which at its end stage requires the production of a Y. pestis exopolysaccharide that bridges the bacteria together in a cohesive, dense biofilm that completely blocks the proventriculus. However, bacterial aggregates are evident within an hour after a flea ingests Y. pestis, and the bacterial exopolysaccharide is not required for this process. In this study, we characterized the biochemical composition of the initial aggregates and demonstrated that the yersinia murine toxin (Ymt), a Y. pestis phospholipase D, greatly enhances rapid aggregation following infected mouse blood meals. The matrix of the bacterial aggregates is complex, containing large amounts of protein and lipid (particularly cholesterol) derived from the flea's blood meal. A similar incidence of proventricular aggregation occurred after fleas ingested whole blood or serum containing Y. pestis, and intact, viable bacteria were not required. The initial aggregation of Y. pestis in the flea gut is likely due to a spontaneous physical process termed depletion aggregation that occurs commonly in environments with high concentrations of polymers or other macromolecules and particles such as bacteria. The initial aggregation sets up subsequent binding aggregation mediated by the bacterially produced exopolysaccharide and mature biofilm that results in proventricular blockage and efficient flea-borne transmission. IMPORTANCE: Yersinia pestis, the bacterial agent of plague, is maintained in nature in mammal-flea-mammal transmission cycles. After a flea feeds on a mammal with septicemic plague, the bacteria rapidly coalesce in the flea's digestive tract to form dense aggregates enveloped in a viscous matrix that often localizes to the foregut. This represents the initial stage of biofilm development that potentiates transmission of Y. pestis when the flea later bites a new host. The rapid aggregation likely occurs via a depletion-aggregation mechanism, a non-canonical first step of bacterial biofilm development. We found that the biofilm matrix is largely composed of host blood proteins and lipids, particularly cholesterol, and that the enzymatic activity of a Y. pestis phospholipase D (Ymt) enhances the initial aggregation. Y. pestis transmitted by flea bite is likely associated with this host-derived matrix, which may initially shield the bacteria from recognition by the host's intradermal innate immune response.

Boric acid alleviates periodontal inflammation induced by IL-1ß in human gingival fibroblasts.

BACKGROUND: Boric acid (BA) has been found to have therapeutic effects on periodontal disease through beneficially affecting antibacterial, anti-viral, and anti-inflammatory actions. METHODS: This study was conducted to determine the effect of BA on cell viability and on mRNA expressions of proinflammatory and anti-inflammatory cytokines and on oxidative stress enzymes induced by IL-1ß (1 ng/mL) in Human Gingival Fibroblasts (HGF) cultured for 24 and 72 h in DMEM media. The BA concentrations added to the media were 0.09 %, 0.18 %, 0.37 %, and 0.75 %. RESULTS: All of the BA concentrations increased the viability of cell cultured in DMEM media only, indicating that these concentrations were not toxic and actually beneficial to cell viability. The addition of 1 ng/m: of IL-1ß decreased cell viability that was overcome by all concentrations of BA at both 24 and 72 h. The IL-1ß addition to the media increased the expressions of the proinflammatory cytokines IL-1ß, IL-6, IL-8, and IL-17; the anti-inflammatory cytokine IL-10; and the oxidative stress enzymes superoxide dismutase (SOD0 and glutathione peroxidase (GPX). The IL-1ß induced increase mRNA expression of IL-1ß was decreased at 24 h by the 0.37 % and 0.75 % BA additions to the media and decreased in a dose-dependent manner by all concentrations of BA at 72 h. The IL-1ß induced increase in the expression of IL-6 was decreased in dose-dependent manner at 72 h by BA. All BA concentrations decreased the IL-1ß induced expression of IL-8 at both 24 and 72 h. The induced increase in IL-17 by IL-1ß was not significantly affected by the BA additions. The increase in the anti-inflammatory cytokine IL10 induced by IL-1ß was increased further by all BA additions in dose dependent manner at both 24 and 72 h. The mRNA expressions of SOD and GPX increased by IL-1ß were further increased by the 0.37 % and 0.75 % BA concentrations at 72 h. CONCLUSIONS: These findings indicate that BA can significantly modulate the cytokines that are involved in inflammatory stress and reactive oxygen species action and thus could be an effective therapeutic agent in the treatment of periodontal disease.

Scanning Electron Microscopy.

Scanning electron microscopy (SEM) remains distinct in its ability to allow topographical visualization of structures. Key elements to consider for successful examination of biological specimens include appropriate preparative and imaging techniques. Chemical processing induces structural artifacts during specimen preparation, and several factors need to be considered when selecting fixation protocols to reduce these effects while retaining structures of interest. Particular care for proper dehydration of specimens is essential to minimize shrinkage and is necessary for placement under the high-vacuum environment required for routine operation of standard SEMs. Choice of substrate for mounting and coating specimens can reduce artifacts known as charging, and a basic understanding of microscope settings can optimize parameters to achieve desired results. This article describes fundamental techniques and tips for routine specimen preparation for a variety of biological specimens, preservation of labile or fragile structures, immune-labeling strategies, and microscope imaging parameters for optimal examination by SEM. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Chemical preparative techniques for preservation of biological specimens for examination by SEM Alternate Protocol 1: Practical considerations for the preparation of soft tissues Alternate Protocol 2: Removal of debris from the exoskeleton of invertebrates Alternate Protocol 3: Fixation of colonies grown on agar plates Alternate Protocol 4: Stabilization of polysaccharide structures with alcian blue and lysine Alternate Protocol 5: Preparation of non-adherent particulates in solution for SEM Support Protocol 1: Application of thin layer of adhesive on substrate to improve adherence Support Protocol 2: Poly-L-lysine coating specimen substrates for improved adherence Support Protocol 3: Microwave processing of biological specimens for examination by SEM Basic Protocol 2: Critical point drying of specimens Alternate Protocol 6: Chemical alternative to critical point drying Basic Protocol 3: Sputter coating Alternate Protocol 7: Improved bulk conductivity through "OTOTO" Basic Protocol 4: Immune-labeling strategies Alternate Protocol 8: Immune-labeling internal antigens with small gold probes Alternate protocol 9: Quantum dot or fluoronanogold preparations for correlative techniques Basic Protocol 5: Exposure of internal structures by mechanical fracturing Basic Protocol 6: Exposure of internal structures of tissues by fracturing with liquid nitrogen Basic Protocol 7: Anaglyph production from stereo pairs to produce 3D images.

Matching Kienböck's Treatment Options to Specific Features of Each Case.

Kienböck's disease is best understood as a continuous interaction between compromised perfusion and structural deterioration that transitions from an early phase to a late phase. Existing literature has failed to identify any one superior treatment for Kienböck's; many studies even demonstrate no advantage for surgery compared with the natural history. Surgical interventions for early and transitional Kienböck's are designed to preserve or reconstruct the lunate. However, in most studies, the only tool used to assess the lunate itself has been plain radiography that neither reveals critical architectural details (demonstrated by computed tomographic scan) nor the vascular status (demonstrated by magnetic resonance imaging). Most articles, therefore, do not adequately define the preoperative status of the lunate or its alteration through surgical intervention. Critical preoperative features that are best demonstrated by these advanced imaging studies have specific anatomic and physiologic relationships that better correspond with certain surgical interventions, which also pair better with specific patient characteristics. This review explains how to identify, analyze, and strategically match these variables with the treatment interventions available for Kienböck's patients through the early, transitional, and late phases of the disease.

Nail Mineral Composition Changes Do Not Reflect Bone Mineral Changes Caused by Boron Supplementation.

Nails have been found to be a non-invasive and readily available tissue whose mineral content can change because of a change in dietary mineral intake. Thus, this study was undertaken to determine whether boron (B) supplementation would change the concentrations of some mineral elements in nails and whether these changes correlated with changes induced in bone. Female New Zealand White rabbits (aged 8 months, 2-2.5 kg weight) were fed a grain-based, high-energy diet containing 3.88 mg B/kg. The rabbits were divided into four treatment groups: controls receiving no supplemental B (N: 7; C) and three groups supplemented with 30 mg B/L in drinking water as borax decahydrate (Na2B4O7∙10H2O, N: 10; BD), borax anhydrous (Na2B4O7, N: 7; Bah), and boric acid (H3BO3, N: 7; BA). Boron, calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), phosphorus (P), potassium (K), sodium (Na), sulfur (S), and zinc (Zn) concentrations in nails were determined by inductively coupled plasma atomic emission spectroscopy. Parametric and non-parametric multiple group comparisons and post hoc tests were performed and whether a correlation between nail and tibia and femur mineral elements concentrations were determined. A p-value of < 0.05 was considered statistically significant. Boron was not detectable in control nails but was found in the nails of the three B supplemented groups. Boron supplementation markedly increased the Ca concentration in nails with the effect greatest in the BA and BD groups. The P and Mg concentrations also were increased by B supplementation with the effect most marked in the BA group. In contrast, B supplementation decreased the Na concentration with the effect most noticeable in the BD and Bah groups. The Zn concentration in nails was not affected by BA and BD supplementation but was decreased by Bah supplementation. Boron supplementation did not significantly affect the concentrations of Cu, Fe, Mo, K, and S in nails. No meaningful significant correlations were found between nail mineral elements and tibia and femur mineral elements found previously. Nails can be an indicator of the response to boron supplementation but are not useful to indicate changes in mineral elements in bone in response to B supplementation.

Boric Acid Reverses Nicotine-Induced Cytokine Expressions of Human Gingival Fibroblasts.

Nicotine, the major bioactive ingredient in tobacco, is a major risk factor for periodontal disease and destruction. Nicotine has been shown to stimulate the production of cytokines that are priming agents for inflammation that induces tissue destruction, such as IL-1ß, IL-6, and IL-8, by gingival keratinocytes and human gingival fibroblasts (HGF). Boron as boric acid has been found to decrease pro-inflammatory cytokines and increase anti-inflammatory cytokines in cells with inflammatory stress. Thus, a study was performed to determine whether boric acid reverses negative effects of nicotine on human gingival fibroblasts (HGFs). The viability and cytokine expressions of HGFs cultured for 24 and 72 h in control medium with no nicotine or boric acid added and in media containing only nicotine, only boric acid, or a combination of BA and nicotine were determined. Nicotine in concentrations of 10-1, 10-2, 10-3,10-4, 10-5, and 10-6 mM significantly reduced cell viability compared to the control. Boric acid at 10 and 50 ng/mL in the media partially restored and 100 ng/mL in the media fully restored the nicotine-depressed HGF cell viability to the same level as the control group. Nicotine elevated the expression of pro-inflammatory cytokines TNF-α, IL-1ß, IL-6, IL-8, and IL-17 and decreased the anti-inflammatory IL-10 in HGFs at 24 and 72 h. Boric acid at 100 ng/mL in the medium prevented the changes induced by nicotine alone. The findings indicate that boric acid can inhibit or reverse nicotine-induced pathology in periodontal tissue and thus may help maintain oral and periodontal health in tobacco users.

Long-term Outcomes for Late-Phase Kienböck's Tenoarthroplasty.

BACKGROUND: In late KienbÓ§ck's, the lunate is fully fragmented and nonreconstructible. Replacing the lunate with a pyrocarbon prosthesis preserves load distribution and avoids carpectomy or fusion, but leaves the wrist intrinsically unstable, requiring additional soft-tissue stabilization techniques. METHODS: Five men and 7 women with a mean age of 43 (±15) years underwent prosthetic replacement of the lunate with dual bundle scaphoid-triquetrum tenodesis for carpal stabilization. The mean follow-up interval from initial surgery was 9.1 (±1.7) years. Outcomes were Disabilities of Arm, Shoulder, and Hand (DASH) score, revision or conversion surgery, and wrist range of motion. RESULTS: The mean DASH score was 8.9 (±7.1). No patients reported any additional revision or conversion surgery. The mean wrist flexion was 60° (±14°); wrist extension was 45° (±21°). CONCLUSIONS: Clinical outcomes proved more favorable than anticipated, particularly the self-rated outcomes scores and the absence of any revision or conversion surgery.

Disruption of the Golgi Apparatus and Contribution of the Endoplasmic Reticulum to the SARS-CoV-2 Replication Complex.

A variety of immunolabeling procedures for both light and electron microscopy were used to examine the cellular origins of the host membranes supporting the SARS-CoV-2 replication complex. The endoplasmic reticulum has long been implicated as a source of membrane for the coronavirus replication organelle. Using dsRNA as a marker for sites of viral RNA synthesis, we provide additional evidence supporting ER as a prominent source of membrane. In addition, we observed a rapid fragmentation of the Golgi apparatus which is visible by 6 h and complete by 12 h post-infection. Golgi derived lipid appears to be incorporated into the replication organelle although protein markers are dispersed throughout the infected cell. The mechanism of Golgi disruption is undefined, but chemical disruption of the Golgi apparatus by brefeldin A is inhibitory to viral replication. A search for an individual SARS-CoV-2 protein responsible for this activity identified at least five viral proteins, M, S, E, Orf6, and nsp3, that induced Golgi fragmentation when expressed in eukaryotic cells. Each of these proteins, as well as nsp4, also caused visible changes to ER structure as shown by correlative light and electron microscopy (CLEM). Collectively, these results imply that specific disruption of the Golgi apparatus is a critical component of coronavirus replication.

Oral Antibiotic Management of Acute Osteomyelitis of the Hand: Outcomes and Cost Comparison to Standard Intravenous Regimen.

Background: Acute, direct inoculation osteomyelitis of the hand has traditionally been managed by intravenous antibiotics. With proven high levels of bone and joint penetration, specific oral antimicrobials may deliver clinical efficacy but at substantially lower cost. Methods: Sixty-nine adult patients with surgically proven acute, direct inoculation osteomyelitis of the hand were evaluated for clinical response on a 6-week postdebridement regimen of susceptibility-matched oral antibiotics. Inclusion required gross purulence and bone loss demonstrated at the initial debridement and radiographic evidence of bone loss. Excluded were 2 patients with extreme medical comorbidities. There were 53 men and 16 women with a mean age of 46 years. Mean follow-up was 16 weeks (±10). The cost model for the outpatient oral antibiotic treatment was intentionally maximized using Walgreen's undiscounted cash price. The cost model for the traditional intravenous treatment regimen was intentionally minimized using the fully discounted Medicare fee schedule. Results: All patients achieved resolution of osteomyelitis by clinical and radiographic criteria. In addition, 7 patients underwent successful subsequent osteosynthesis procedures at the previously affected site without reactivation. The mean postdebridement direct cost of care per patient in the study cohort was $482.85, the cost of the antibiotic alone. The postdebridement direct cost of care per patient on a regimen of vancomycin 1.5 g every 12 hours via peripherally inserted central catheter line was $21 646.90. Conclusions: Acute, direct inoculation osteomyelitis of the hand can be successfully managed on oral antibiotic agents with substantial direct and indirect cost savings.

Borate and boric acid supplementation of drinking water alters teeth and bone mineral density and composition differently in rabbits fed a high protein and energy diet.

The reported beneficial effects of boron on mineralized tissues in animals and humans vary. Thus, a study was performed to assess whether the variability was the result of different forms of boron supplementation, method of supplementation, and increased adiposity of the rabbit experimental model. Thirty-one female New Zealand White rabbits, (aged 8 months, 2-2.5 kg weight) were fed a grain-based high energy diet containing 11.76 MJ/kg (2850 kcal/kg) and 3.88 mg boron/kg. The rabbits were randomly divided into four treatment groups: Control group was not supplemented with boron (n:7; C), and three groups supplemented with 30 mg boron/L in drinking water in the forms of borax decahydrate (Na2O4B7 10H2O, n:10; BD), borax anhydrous (Na2O4B7, n:7; Bah) or boric acid (H2BO3, n:7; BA). Cone beam micro computed tomographic (micro-CT), histological and elemental analysis was used to evaluate the bones/teeth. Results of the experiments demonstrated that boron supplementation had beneficial effects on mineralized tissue but varied with the type of treatment. Mineral density of the femur was increased by the Bah and BA treatments (p < 0.001), but only BA increased mineral density in the tibia (p = 0.015). In incisor teeth, mineral density of dentin was increased by all boron treatments (p < 0.001), and mineral density of enamel was increased by the BD and Bah treatments. Mineral analysis found that all boron treatments increased the boron concentration in tibia and femur. In the tibia, both the BD and Bah treatments decreased the iron concentration, and the BD treatment decreased the magnesium concentration. Sodium and zinc concentrations in the tibia were decreased by the Bah and BA treatments. The boron treatments did not significantly affect the calcium, copper, molybdenum, potassium phosphorus, and sulfur concentrations. The findings show that boron supplementation can have beneficial effects on mineralized tissues in an animal model with increased adiposity, which is a model of increased inflammatory stress. However, this effect varies with the form of boron supplemented, the method of supplementation, and the mineralized tissue examined.

Cost-effectiveness analysis of atraumatic restorative treatment to manage early childhood caries: microsimulation modelling.

BACKGROUND: This study assessed the cost-effectiveness of atraumatic restorative treatment and the Hall Technique approach (ART/HT) in managing dental caries in young children under the health provider perspective in order to explore a best-buy alternative to dental general anaesthesia (DGA). METHODS: Sixty-five observations from a randomized controlled trial were used to construct 20 000 microsimulations representing individual-level clinical outcome and costs of the DGA and ART/HT. Outcome was percentage of successfully managed cases. Costs were reported in 2020 price. Three different scenarios with different assumptions of clinical success of the DGA and the ART/HT were analysed. Probabilistic sensitivity analysis was carried out. RESULTS: The ART/HT successfully managed more cases at lower cost ($557) than the DGA when the system failure of the DGA was considered. Under per protocol analysis, participants in both arms were successfully managed, but the ART/HT costed $580 less than the DGA. Probabilistic sensitivity analysis confirmed the ART/HT was a dominant intervention. CONCLUSIONS: The ART/HT approach was non-inferior in managing dental caries in young children but at lower costs than the DGA. The ART/HT could be a viable option in the provision of comprehensive dental care in locations with limited access to DGA and reduce hospital admission.

Voluntary running of defined distances alters bone microstructure in C57BL/6 mice fed a high-fat diet.

Obesity increases the risk for pathological conditions such as bone loss. On the other hand, physical exercise reduces body adiposity. To test the hypothesis that physical activity improves bone quality, we evaluated voluntary running of defined distances on trabecular and cortical microstructure in mice fed a high-fat diet (HFD). Sedentary mice were fed the standard AIN93G diet or the HFD. Mice fed the HFD remained sedentary or were assigned to unrestricted running or 75%, 50%, and 25% of unrestricted running with an average running activity at 8.3, 6.3, 4.2, and 2.1 km per day, respectively. The bone structural differences found in sedentary mice were that HFD, compared with the AIN93G diet, resulted in a lower bone volume fraction (BV/TV) and a higher structure model index (SMI) in vertebrae. Running had a greater effect on trabecular microstructure in femurs than in vertebrae; the decrease in SMI and an increase in trabecular thickness (Tb.Th) were in dose-dependent manners. Running was positively correlated with BV/TV and Tb.Th and inversely correlated with SMI in femurs. The HFD increased plasma concentrations of tartrate-resistant acid phosphatase 5b, a marker of bone resorption, in sedentary mice, while running decreased it in a dose-dependent manner. The findings show that voluntary running improves bone quality in young adult mice fed an HFD. Novelty: The high-fat diet alters bone microstructure by increasing bone resorption. Quantitative voluntary running improves bone microstructure through its attenuation of bone resorption in mice fed a high-fat diet.

Magical Mathematical Formulas for Nanoboxes.

Hollow nanostructures are at the forefront of many scientific endeavors. These consist of nanoboxes, nanocages, nanoframes, and nanotubes. We examine the mathematics of atomic coordination in nanoboxes. Such structures consist of a hollow box with n shells and t outer layers. The magical formulas we derive depend on both n and t. We find that nanoboxes with t = 2  or  3, or walls with only a few layers generally have bulk coordinated atoms. The benefits of low-coordination in nanostructures is shown to only occur when the wall thickness is much thinner than normally synthesized. The case where t = 1 is unique, and has distinct magic formulas. Such low-coordinated nanoboxes are of interest for a myriad variety of applications, including batteries, fuel cells, plasmonic, catalytic and biomedical uses. Given these formulas, it is possible to determine the surface dispersion of the nanoboxes. We expect these formulas to be useful in understanding how the atomic coordination varies with n and t within a nanobox.

Boron as Boric Acid Induces mRNA Expression of the Differentiation Factor Tuftelin in Pre-Osteoblastic MC3T3-E1 Cells.

The effects of boron on the formation and maintenance of mineralized structures at the molecular level are still not clearly defined. Thus, a study was conducted using MC3T3-E1 cells to determine whether boron affected mRNA expressions of genes associated with bone/alveolar bone formation around the teethMC3T3-E1 (clone 4) cells were cultured in media treated with boric acid at concentrations of 0, 0.1, 10, 100, or 1000 ng/ml. Total RNAs of each group were isolated on day 3. Gene expression profiles were determined by using RT2 Profiler PCR micro-array that included 84 genes associated with osteogenic differentiation. Tuftelin1 mRNA expression was upregulated by all boron treatments. The upregulation was confirmed by quantitative RT-PCR using the tuftelin probe. While 100 ng/ml had no effect on the integrin-α2 (Itga2) transcript and 1 ng/ml boric acid induced Itga2 mRNA expression (2.1-fold), 0.1, 10, and 1000 ng/ml boric acid downregulated the integrin-α2 gene transcript 2.2-, 1.5-, and 2.1-fold respectively. While 0.1 ng/ml boric acid induced BMP6, increased BMP1r mRNA expression (1.5 fold) was observed in 1000 ng/ml boric acid treatment. The findings suggest that boron affects the regulation of the tuftelin1 gene in osteoblastic cells. Further studies are needed to establish that the beneficial actions of boron on alveolar bone and tooth formation and maintenance include an effect on the expression of the tuftelin1 gene.

Transcriptomic profiling of the digestive tract of the rat flea, Xenopsylla cheopis, following blood feeding and infection with Yersinia pestis.

Yersinia pestis, the causative agent of plague, is a highly lethal pathogen transmitted by the bite of infected fleas. Once ingested by a flea, Y. pestis establish a replicative niche in the gut and produce a biofilm that promotes foregut colonization and transmission. The rat flea Xenopsylla cheopis is an important vector to several zoonotic bacterial pathogens including Y. pestis. Some fleas naturally clear themselves of infection; however, the physiological and immunological mechanisms by which this occurs are largely uncharacterized. To address this, RNA was extracted, sequenced, and distinct transcript profiles were assembled de novo from X. cheopis digestive tracts isolated from fleas that were either: 1) not fed for 5 days; 2) fed sterile blood; or 3) fed blood containing ~5x108 CFU/ml Y. pestis KIM6+. Analysis and comparison of the transcript profiles resulted in identification of 23 annotated (and 11 unknown or uncharacterized) digestive tract transcripts that comprise the early transcriptional response of the rat flea gut to infection with Y. pestis. The data indicate that production of antimicrobial peptides regulated by the immune-deficiency pathway (IMD) is the primary flea immune response to infection with Y. pestis. The remaining infection-responsive transcripts, not obviously associated with the immune response, were involved in at least one of 3 physiological themes: 1) alterations to chemosensation and gut peristalsis; 2) modification of digestion and metabolism; and 3) production of chitin-binding proteins (peritrophins). Despite producing several peritrophin transcripts shortly after feeding, including a subset that were infection-responsive, no thick peritrophic membrane was detectable by histochemistry or electron microscopy of rat flea guts for the first 24 hours following blood-feeding. Here we discuss the physiological implications of rat flea infection-responsive transcripts, the function of X. cheopis peritrophins, and the mechanisms by which Y. pestis may be cleared from the flea gut.

Atraumatic restorative treatments reduce the need for dental general anaesthesia: a non-inferiority randomized, controlled trial.

BACKGROUND: A dental general anaesthesia (DGA) is commonly undertaken for the management of dental caries in young children. A randomized-controlled trial was undertaken to test the feasibility of using the Atraumatic Restorative Treatment and Hall Technique approaches (ART/HT) to manage the dental treatment of children recommended for a DGA. METHODS: Consenting children, recommended a DGA for caries management, at the Oral Health Centre of Western Australia were randomized. Test group children were treated using the ART/HT approach and the control group under a DGA. Children were examined after 12 months by two blinded, calibrated examiners. Analysis was on an intention to treat basis; between and within group comparisons were undertaken using appropriate paired and unpaired tests. Logistic regression was used to test restorative success, controlling for clustering of teeth. RESULTS: Sixty-five children participated, (Test = 32; Control = 33). At study termination, 28 children (88%) in the ART/HT group and 20 children (61%) in the DGA group had been provided with care, P < 0.01. Crown restorations were protective of restorative failure in a multivariate logistic model (OR 0.05, P < 0.01). CONCLUSION: Use of the ART/HT approach enabled timely dental treatment of young children recommended for a DGA, and should be among the treatment options considered.

Dietary Selenium Supplementation Does Not Attenuate Mammary Tumorigenesis-Mediated Bone Loss in Male MMTV-PyMT Mice.

Bone wasting occurs during the progression of breast cancer and contributes to breast cancer mortality. We evaluated the effect of methylseleninic acid (MSeA), an anti-carcinogenic form of selenium, on bone microstructural changes in the presence of mammary tumors in a male breast cancer model of mouse mammary tumor virus-polyomavirus middle T-antigen (MMTV-PyMT). In this study, we performed microcomputed tomographic analysis of femurs and vertebrae collected from a study showing that dietary supplementation with MSeA reduces mammary tumorigenesis in male mice. Compared to age-matched, non-tumor-bearing mice (MMTV-PyMT negative), the presence of mammary tumors significantly reduced the bone volume fraction, trabecular thickness, and bone mineral density while it increased the structure model index in femurs, but not in vertebrae. Moreover, mammary tumorigenesis decreased plasma concentrations of osteocalcin. Supplementation with MSeA did not affect these changes in MMTV-PyMT mice. In conclusion, mammary tumorigenesis caused bone loss in MMTV-PyMT mice. However, dietary supplementation with MSeA did not attenuate mammary tumor-associated bone loss in this model of male breast cancer.