Simultaneous Assessment of Acidogenesis-Mitigation and Specific Bacterial Growth-Inhibition by Dentifrices

Dentifrices can augment oral hygiene by inactivating bacteria and at sub-lethal concentrations may affect bacterial metabolism, potentially inhibiting acidogenesis, the main cause of caries. Reported herein is the development of a rapid method to simultaneously measure group-specific bactericidal and acidogenesis-mitigation effects of dentifrices on oral bacteria. Saliva was incubated aerobically and anaerobically in Tryptone Soya Broth, Wilkins-Chalgren Broth with mucin, or artificial saliva and was exposed to dentifrices containing triclosan/copolymer (TD); sodium fluoride (FD); stannous fluoride and zinc lactate (SFD1); or stannous fluoride, zinc lactate and stannous chloride (SFD2). Minimum inhibitory concentrations (MIC) were determined turbidometrically whilst group-specific minimum bactericidal concentrations (MBC) were assessed using growth media and conditions selective for total aerobes, total anaerobes, streptococci and Gram-negative anaerobes. Minimum acid neutralization concentration (MNC) was defined as the lowest concentration of dentifrice at which acidification was inhibited. Differences between MIC and MNC were calculated and normalized with respect to MIC to derive the combined inhibitory and neutralizing capacity (CINC), a cumulative measure of acidogenesis-mitigation and growth inhibition. The overall rank order for growth inhibition potency (MIC) under aerobic and anaerobic conditions was: TD> SFD2> SFD1> FD. Acidogenesis-mitigation (MNC) was ordered; TD> FD> SFD2> SFD1. CINC was ordered TD> FD> SFD2> SFD1 aerobically and TD> FD> SFD1> SFD2 anaerobically. With respect to group-specific bactericidal activity, TD generally exhibited the greatest potency, particularly against total aerobes, total anaerobes and streptococci. This approach enables the rapid simultaneous evaluation of acidity mitigation, growth inhibition and specific antimicrobial activity by dentifrices.     

Growth and Activities of Sulfate-Reducing and Methanogenic Bacteria in Human Oral Cavity

Viable counts and activities of sulfate-reducing bacteria (SRB) and methanogenic bacteria were determined in the oral cavities of eight volunteers. Of these, seven harbored viable SRB populations, and six harbored viable methanogenic bacterial populations. Two volunteers classified as type III periodontal patients had both SRB and methanogenic bacteria. Six separate sites were sampled: posterior tongue, anterior tongue, mid-buccal mucosa, vestibular mucosa, supragingival plaque, and subgingival plaque. The SRB was found in all areas in one volunteer, and it was mostly present in posterior tongue, anterior tongue, supragingival, and subgingival plaques in many volunteers. The methanogenic bacteria were mostly found in supragingival and subgingival plaques. The activities of sulfate reduction and methane production were determined in randomly selected isolates. Received: 27 July 2002 / Accepted: 27 August 2002     

Nonalcoholic Hepatic Steatosis Is a Strong Predictor of High-Risk Coronary-Artery Plaques as Determined by Multidetector CT

Background

Nonalcoholic fatty liver disease is associated with a risk of coronary artery disease (e.g., diabetes mellitus, dyslipidemia, metabolic syndrome). We evaluated whether nonalcoholic hepatic steatosis is associated with high-risk plaques as assessed by multidetector computed tomography (CT).

Methods

This retrospective study involved 414 participants suspected of having coronary artery disease. Nonalcoholic hepatic steatosis was defined as a liver-to-spleen fat ratio of <1.0 and the presence and appropriate characteristics of coronary-artery plaques as assessed by coronary CT angiography. High-risk plaques were identified, as were low-density plaques, positive remodeling, and spotty calcification.

Results

Compared with patients who did not have nonalcoholic hepatic steatosis, patients with nonalcoholic hepatic steatosis had more low-density plaques (21% vs. 44%, p<0.01), positive remodeling (41% vs. 58%, p = 0.01), and spotty calcification (12% vs. 36%, p<0.01). The number of high-risk plaques in patients with nonalcoholic hepatic steatosis was greater than in those without nonalcoholic hepatic steatosis (p<0.01). Patients with nonalcoholic hepatic steatosis were more likely to have high-risk plaques than were those with only an elevated level of visceral adipose tissue (≥86 cm²; 35% vs. 16%, p<0.01). Multivariate analyses that included nonalcoholic hepatic steatosis, amount of visceral adipose tissue, and the presence/absence of traditional risk factors demonstrated that nonalcoholic hepatic steatosis was an independent predictor of high-risk plaques (odds ratio: 4.60; 95% confidence interval: 1.94–9.07, p<0.01).

Conclusions

Diagnosis of nonalcoholic hepatic steatosis may be of value when assessing the risk of coronary artery disease.     

Plaque Formation in Chick Embryo Fibroblast Cells by Chlamydia Isolated From Avian and Mammalian Sources

Fifteen strains of chlamydial agents, 2 Chlamydia trachomatis and 13 Chlamydia psittaci, were tested for plaque formation on chick embryo fibroblast cells. C. trachomatis strains did not form plaques; 12 strains of C. psittaci did form plaques and 1 strain did not. The distribution of plaque sizes with C. psittaci strains was studied and it was found that the 12 strains could be tentatively grouped into three plaquing types: small (<0.50 mm), intermediate (0.50 to 0.90 mm), and large (>0.90 mm). Small plaques were predominantly associated with strains M56, ET, CP3, CT4, EBA, CS1, and CT2. Intermediate size plaques were predominantly associated with strains NJ1, VT1, and H81. Large plaques were predominantly associated with strains WC and OG. Plaque size appears to be related to virulence of Chlamydia for laboratory animals.     

Screening of Miners and Millers at Decreasing Levels of Asbestos Exposure: Comparison of Chest Radiography and Thin-Section Computed Tomography

Background

Chest radiography (CXR) is inferior to Thin-section computed tomography in the detection of asbestos related interstitial and pleural abnormalities. It remains unclear, however, whether these limitations are large enough to impair CXR´s ability in detecting the expected reduction in the frequency of these asbestos-related abnormalities (ARA) as exposure decreases.

Methods

Clinical evaluation, CXR, Thin-section CT and spirometry were obtained in 1418 miners and millers who were exposed to progressively lower airborne concentrations of asbestos. They were separated into four groups according to the type, period and measurements of exposure and/or procedures for controlling exposure: Group I (1940–1966/tremolite and chrysotile, without measurements of exposure and procedures for controlling exposure); Group II (1967–1976/chrysotile only, without measurements of exposure and procedures for controlling exposure); Group III (1977–1980/chrysotile only, initiated measurements of exposure and procedures for controlling exposure) and Group IV (after 1981/chrysotile only, implemented measurements of exposure and a comprehensive procedures for controlling exposure).

Results

In all groups, CXR suggested more frequently interstitial abnormalities and less frequently pleural plaques than observed on Thin-section CT (p<0.050). The odds for asbestosis in groups of decreasing exposure diminished to greater extent at Thin-section CT than on CXR. Lung function was reduced in subjects who had pleural plaques evident only on Thin-section CT (p<0.050). In a longitudinal evaluation of 301 subjects without interstitial and pleural abnormalities on CXR and Thin-section CT in a previous evaluation, only Thin-section CT indicated that these ARA reduced as exposure decreased.

Conclusions

CXR compared to Thin-section CT was associated with false-positives for interstitial abnormalities and false-negatives for pleural plaques, regardless of the intensity of asbestos exposure. Also, CXR led to a substantial misinformation of the effects of the progressively lower asbestos concentrations in the occurrence of asbestos-related diseases in miners and millers.     

Growth, incidence and activities of dissimilatory sulfate-reducing bacteria in the human oral cavity

Abstract Viable counts and activities of sulfate-reducing bacteria were determined in the oral cavities of 12 healthy volunteers. Of these, 10 harboured viable sulfate-reducing bacteria populations. Six separate sites were sampled: the posterior tongue, anterior tongue, mid buccal mucosa, vestibular mucosa, supragingival plaque and subgingival plaque. Sulfate-reducing bacteria occurred in all areas, with the highest incidence in supragingival plaque. Viable counts and sulfate-reducing activities in each of the regions varied from 0 to 10⁸ cfu (g wet weight)⁻¹ and from 0 to 50 nmol (g wet weight) ⁻¹ h⁻¹, respectively. As sulfate-reducing bacteria can be detected in the oral cavity, they may potentially be involved in terminal oxidative processes carried out by the microflora of the mouth.     

Analysis of Oral Microbiota in Children with Dental Caries by PCR-DGGE and Barcoded Pyrosequencing

Oral microbiota plays a vital role in maintaining the homeostasis of oral cavity. Dental caries are among the most common oral diseases in children and pathogenic bacteria contribute to the development of the disease. However, the overall structure of bacterial communities in the oral cavity from children with dental caries has not been explored deeply heretofore. We used high-throughput barcoded pyrosequencing and PCR-denaturing gradient gel electrophoresis (DGGE) to examine bacterial diversity of oral microbiota in saliva and supragingival plaques from 60 children aged 3 to 6 years old with and without dental caries from China. The multiplex barcoded pyrosequencing was performed in a single run, with multiple samples tagged uniquely by multiplex identifiers. As PCR-DGGE analysis is a conventional molecular ecological approach, this analysis was also performed on the same samples and the results of both approaches were compared. A total of 186,787 high-quality sequences were obtained for evaluating bacterial diversity and 41,905 unique sequences represented all phylotypes. We found that the oral microbiota in children was far more diverse than previous studies reported, and more than 200 genera belonging to ten phyla were found in the oral cavity. The phylotypes in saliva and supragingival plaques were significantly different and could be divided into two distinct clusters (p < 0.05). The bacterial diversity in oral microbiome analyzed by PCR-DGGE and barcoded pyrosequencing was employed to cross validate the data sets. The genera of Streptococcus, Veillonella, Actinomyces, Granulicatella, Leptotrichia, and Thiomonas in plaques were significantly associated with dental caries (p < 0.05). The results showed that there was no one specific pathogen but rather pathogenic populations in plaque that significantly correlated with dental caries. The enormous diversity of oral microbiota allowed for a better understanding of oral microecosystem, and these pathogenic populations in plaque provide new insights into the etiology of dental caries and suggest new targets for interventions of the disease.     

Bacteriophages Reduce Experimental Contamination of Hard Surfaces, Tomato, Spinach, Broccoli, and Ground Beef by Escherichia coli O157:H7

A bacteriophage cocktail (designated ECP-100) containing three Myoviridae phages lytic for Escherichia coli O157:H7 was examined for its ability to reduce experimental contamination of hard surfaces (glass coverslips and gypsum boards), tomato, spinach, broccoli, and ground beef by three virulent strains of the bacterium. The hard surfaces and foods contaminated by a mixture of three E. coli O157:H7 strains were treated with ECP-100 (test samples) or sterile phosphate-buffered saline buffer (control samples), and the efficacy of phage treatment was evaluated by comparing the number of viable E. coli organisms recovered from the test and control samples. Treatments (5 min) with the ECP-100 preparation containing three different concentrations of phages (10¹⁰, 10⁹, and 10⁸ PFU/ml) resulted in statistically significant reductions (P = <0.05) of 99.99%, 98%, and 94%, respectively, in the number of E. coli O157:H7 organisms recovered from the glass coverslips. Similar treatments resulted in reductions of 100%, 95%, and 85%, respectively, in the number of E. coli O157:H7 organisms recovered from the gypsum board surfaces; the reductions caused by the two most concentrated phage preparations were statistically significant. Treatment with the least concentrated preparation that elicited significantly less contamination of the hard surfaces (i.e., 10⁹ PFU/ml) also significantly reduced the number of viable E. coli O157:H7 organisms on the four food samples. The observed reductions ranged from 94% (at 120 ± 4 h posttreatment of tomato samples) to 100% (at 24 ± 4 h posttreatment of spinach samples). The data suggest that naturally occurring bacteriophages may be useful for reducing contamination of various hard surfaces, fruits, vegetables, and ground beef by E. coli O157:H7.     

Sex Determination and Polyploid Gigantism in the Dwarf Surfclam (Mulinia Lateralis Say)

Mulinia lateralis, the dwarf surfclam, is a suitable model for bivalve genetics because it is hardy and has a short generation time. In this study, gynogenetic and triploid. M. lateralis were successfully induced. For gynogenesis, eggs were fertilized with sperm irradiated with ultraviolet light and subsequently treated with cytochalasin B to block the release of the second polar body (PB2). Triploidy was induced by blocking PB2 in normally fertilized eggs. The survival of gynogenetic diploids was very low, only 0.7% to 8 days post-fertilization (PF), compared with 15.2% in the triploid groups and 27.5% in the normal diploid control. Larvae in all groups metamorphosed at 8-10 days PF, and there was no significant post-larval mortality. At sexual maturation (2-3 months PF), all gynogenetic diploids were female, and there was no significant difference (P > 0.05) in sex ratio between diploids and triploids. These results suggested that the dwarf surfclam may have an XX-female, XY-male sex determination with Y-domination. Compared with diploids, triploids had a relative fecundity of 59% for females and 80% for males. Eggs produced by triploid females were 53% larger (P < 0.001) in volume than those from diploid females. In both length and weight measurements at three months PF, the gynogenetic diploids were not significantly (P > 0.33) different from normal diploid females, suggesting that inbreeding depression was minimal in meiosis II gynogens. Triploid clams were significantly larger (P < 0.001) than normal diploids. We hypothesize that the increased body-size in triploids was caused by a polyploid gigantism due to the increased cell volume and a lack of cell-number compensation.     

Molecular Analysis of the Subgingival Microbiota in Health and Disease

This investigation provides molecular analyses of the periodontal microbiota in health and disease. Subgingival samples from 47 volunteers with healthy gingivae or clinically diagnosed chronic periodontitis were characterized by PCR-denaturing gradient gel electrophoresis (DGGE) with primers specific for the V2-V3 region of the eubacterial 16S rRNA gene. A hierarchical dendrogram was constructed from band patterns. All unique PCR amplicons (DGGE bands) were sequenced for identity. Samples were also analyzed for the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythensis by multiplex PCR. Associations of patient age, gender, and smoking status together with the presence of each unique band and putative periodontal pathogens with disease were assessed by logistic regression. Periodontal pockets were colonized by complex eubacterial communities (10 to 40 distinct DGGE bands) with substantial individual variation in the community profile. Species diversity in health and disease was determined by the Shannon-Weaver index of diversity and compared by the Mann-Whitney U test. Sequence analyses of DGGE amplicons indicated the occurrence of many nontypical oral species and eubacteria previously associated with this environment. With the exception of T. forsythensis, the putative pathogens were not detected by DGGE. Multiplex PCR, however, detected T. forsythensis, A. actinomycetemcomitans, and P. gingivalis in 9% 16%, and 29% of the patients with disease, respectively. The presence of A. actinomycetemcomitans was significantly associated with disease (P < 0.01). Statistical analyses indicated that the presence of Treponema socranskii and Pseudomonas sp. was a significant predictor of disease (P < 0.05) and that there was no significant difference (P > 0.05) in terms of eubacterial species diversity between health and disease.     

Cyclic nucleotide-gated channels of rat olfactory receptor cells: divalent cations control the sensitivity to cAMP

cAMP-gated channels were studied in inside-out membrane patches excised from the apical cellular pole of isolated olfactory receptor cells of the rat. In the absence of divalent cations the dose-response curve of activation of patch current by cAMP had a KM of 4.0 microM at -50 mV and of 2.5 microM at +50 mV. However, addition of 0.2 or 0.5 mM Ca2+ shifted the KM of cAMP reversibly to the higher cAMP concentrations of 33 or 90 microM, respectively, at -50 mV. Among divalent cations, the relative potency for inducing cAMP affinity shifts was: Ca2+ > Sr2+ > Mn2+ > Ba2+ > Mg2+, of which Mg2+ (up to 3 mM) did not shift the KM at all. This potency sequence corresponds closely to that required for the activation of calmodulin. However, the Ca(2+)-sensitivity is lower than expected for a calmodulin-mediated action. Brief (60 s) transient exposure to 3 mM Mg2+, in the absence of other divalent cations, had a protective effect in that following washout of Mg2+, subsequent exposure to 0.2 mM Ca2+ no longer caused affinity shifts. This protection effect did not occur in intact cells and was probably a consequence of patch excision, possibly representing ablation of a regulatory protein from the channel cyclic nucleotide binding site. Thus, the binding of divalent cations, probably via a regulatory protein, controls the sensitivity of the cAMP-gated channels to cAMP. The influx of Ca2+ through these channels during the odorant response may rise to a sufficiently high concentration at the intracellular membrane surface to contribute to the desensitization of the odorant- induced response. The results also indicate that divalent cation effects on cyclic nucleotide-gated channels may depend on the sequence of pre-exposure to other divalent cations.     

The Effect of Three Different (-135°C) Whole Body Cryotherapy Exposure Durations on Elite Rugby League Players

Background

Whole body cryotherapy (WBC) is the therapeutic application of extreme cold air for a short duration. Minimal evidence is available for determining optimal exposure time.

Purpose

To explore whether the length of WBC exposure induces differential changes in inflammatory markers, tissue oxygenation, skin and core temperature, thermal sensation and comfort.

Method

This study was a randomised cross over design with participants acting as their own control. Fourteen male professional first team super league rugby players were exposed to 1, 2, and 3 minutes of WBC at −135°C. Testing took place the day after a competitive league fixture, each exposure separated by seven days.

Results

No significant changes were found in the inflammatory cytokine interleukin six. Significant reductions (p<0.05) in deoxyhaemoglobin for gastrocnemius and vastus lateralis were found. In vastus lateralis significant reductions (p<0.05) in oxyhaemoglobin and tissue oxygenation index (p<0.05) were demonstrated. Significant reductions (p<0.05) in skin temperature were recorded. No significant changes were recorded in core temperature. Significant reductions (p<0.05) in thermal sensation and comfort were recorded.

Conclusion

Three brief exposures to WBC separated by 1 week are not sufficient to induce physiological changes in IL-6 or core temperature. There are however significant changes in tissue oxyhaemoglobin, deoxyhaemoglobin, tissue oxygenation index, skin temperature and thermal sensation. We conclude that a 2 minute WBC exposure was the optimum exposure length at temperatures of −135°C and could be applied as the basis for future studies.     

Short-term in-season ballistic training improves power,muscle volume and throwing velocity in junior handball players. A randomized control trial

This study investigated the effects of a ballistic training programme using an arm/shoulder specific strength device (ASSSD) on the upper body peak power (PP), muscle volume (MV) of the dominant arm and throwing velocity in junior handball players. Twenty-six players were randomly assigned to an experimental (EG = 15, age 17.6 ± 0.51 years) and control (CG = 11, age 17.36 ± 0.50 years) group. Over an 8-week in-season period, the EG performed a ballistic training programme (2 sessions/week) immediately before their normal team handball training. Both groups underwent tests on the ASSSD, which operates in consecutive accelerative and decelerative actions, for throwing characteristics determination. Peak power (PP), peak force (PF), peak velocity (PV), peak rate of power development (PRPD), muscle volume (MV), throwing velocity with runup, standing throw, and jump throw were also assessed before/after the training programme. The EG group showed significant post-training improvements in PP (52.50% – p < 0.001), PF (26.45% – p < 0.01) and PRPD (78.47% – p < 0.001) better than the CG (1.81, 0.67 and 1.64%, p > 0.05, respectively). There was also a post-training improvement in the velocity at PP (22.82% – p < 0.001) and PF (42.45% – p < 0.001) in the EG compared to the CG (4.18 and 8.53%, p > 0.05 respectively). There was a significant increase in acceleration at PP (51.50% – p < 0.01) and PF (69.67% – p < 0.001). MV increased (19.11% – p < 0.001) in the EG, with no significant change (3.34% – p = 0.84) in the CG. Finally, significant increases were obtained in the three throw types (3.1–6.21%, p < 0.05- < 0.001) in the EG compared to the CG. The additional ASSSD training protocol was able to improve muscle strength/volume and ball throwing velocity in junior handball players.     

Active Invasion of Oral and Aortic Tissues by Porphyromonas gingivalis in Mice Causally Links Periodontitis and Atherosclerosis

Atherosclerotic vascular disease is a leading cause of myocardial infarction and cerebrovascular accident, and independent associations with periodontal disease (PD) are reported. PD is caused by polymicrobial infections and aggressive immune responses. Genomic DNA of Porphyromonas gingivalis, the best-studied bacterial pathogen associated with severe PD, is detected within atherosclerotic plaque. We examined causal relationships between chronic P. gingivalis oral infection, PD, and atherosclerosis in hyperlipidemic ApoE^null mice. ApoE^null mice (n = 24) were orally infected with P. gingivalis for 12 and 24 weeks. PD was assessed by standard clinical measurements while the aorta was examined for atherosclerotic lesions and inflammatory markers by array. Systemic inflammatory markers serum amyloid A, nitric oxide, and oxidized low-density lipoprotein were analyzed. P. gingivalis infection elicited specific antibodies and alveolar bone loss. Fluorescent in situ hybridization detected viable P. gingivalis within oral epithelium and aorta, and genomic DNA was detected within systemic organs. Aortic plaque area was significantly increased in P. gingivalis-infected mice at 24 weeks (P<0.01). Aortic RNA and protein arrays indicated a strong Th2 response. Chronic oral infection with P. gingivalis results in a specific immune response, significant increases in oral bone resorption, aortic inflammation, viable bacteria in oral epithelium and aorta, and plaque development.     

A Presenilin-1 Mutation Identified in Familial Alzheimer Disease with Cotton Wool Plaques Causes a Nearly Complete Loss of γ-Secretase Activity

Mutations in presenilin-1 and presenilin-2 (PS1 and PS2) are the most common cause of familial Alzheimer disease. PS1 and PS2 are the presumptive catalytic components of the multisubunit γ-secretase complex, which proteolyzes a number of type I transmembrane proteins, including the amyloid precursor protein (APP) and Notch. APP processing by γ-secretase produces β-amyloid peptides (Aβ40 and Aβ42) that accumulate in the Alzheimer disease brain. Here we identify a pathogenic L435F mutation in PS1 in two affected siblings with early-onset familial Alzheimer disease characterized by deposition of cerebral cotton wool plaques. The L435F mutation resides in a conserved C-terminal PAL sequence implicated in active site conformation and catalytic activity. The impact of PS1 mutations in and around the PAL motif on γ-secretase activity was assessed by expression of mutant PS1 in mouse embryo fibroblasts lacking endogenous PS1 and PS2. Surprisingly, the L435F mutation caused a nearly complete loss of γ-secretase activity, including >90% reductions in the generation of Aβ40, Aβ42, and the APP and Notch intracellular domains. Two nonpathogenic PS1 mutations, P433L and L435R, caused essentially complete loss of γ-secretase activity, whereas two previously identified pathogenic PS1 mutations, P436Q and P436S, caused partial loss of function with substantial reductions in production of Aβ40, Aβ42, and the APP and Notch intracellular domains. These results argue against overproduction of Aβ42 as an essential property of presenilin proteins bearing pathogenic mutations. Rather, our findings provide support for the hypothesis that pathogenic mutations cause a general loss of presenilin function.     

High-Pressure Inactivation of Hepatitis A Virus within Oysters

Previous results demonstrated that hepatitis A virus (HAV) could be inactivated by high hydrostatic pressure (HHP) (D. H. Kingsley, D. Hoover, E. Papafragkou, and G. P. Richards, J. Food Prot. 65:1605-1609, 2002); however, direct evaluation of HAV inactivation within contaminated oysters was not performed. In this study, we report confirmation that HAV within contaminated shellfish is inactivated by HHP. Shellfish were initially contaminated with HAV by using a flowthrough system. PFU reductions of >1, >2, and >3 log₁₀ were observed for 1-min treatments at 350, 375, and 400 megapascals, respectively, within a temperature range of 8.7 to 10.3°C. Bioconcentration of nearly 6 log₁₀ PFU of HAV per oyster was achieved under simulated natural conditions. These results suggest that HHP treatment of raw shellfish will be a viable strategy for the reduction of infectious HAV.     

Pericardial Fat Is Associated with Coronary Artery Calcification in Non-Dialysis Dependent Chronic Kidney Disease Patients

Pericardial fat (PF) a component of visceral adipose tissue has been consistently related to coronary atherosclerosis in the general population. This study evaluated the association between PF and coronary artery calcification (CAC) in non-dialysis dependent chronic kidney disease (CKD) patients. This is a post-hoc cross sectional analysis of the baseline of a prospective cohort of 117 outward CKD patients without manifest coronary artery disease (age, 56.9±11.0 years, 64.1% males, 95.1% hypertensives, 25.2% diabetics, 15.5% ever smokers, CKD stage 2 to 5 with estimated glomerular filtration rate 36.8±18.1 ml/min). CAC scores, PF volume and abdominal visceral fat (AVF) areas were measured by computed tomography. The association of PF as a continuous variable with the presence of CAC was analyzed by multivariate logistic regression. CAC (calcium score >0) was present in 59.2% patients. Those presenting CAC were on average 10 years older, had a higher proportion of male gender (78.7% vs. 42.9%, p<0.001), and had higher values of waist circumference (95.9±10.7 vs. 90.2±13.2 cm, p = 0.02), PF volumes (224.8±107.6 vs. 139.1±85.0 cm³, p<0.01) and AVF areas (109.2±81.5 vs. 70.2±62.9 cm², p = 0.01). In the multivariate analysis, adjusting for age, gender, diabetes, smoking and, left ventricular concentric hypertrophy, PF was significantly associated with the presence of CAC (OR: 1.88 95% CI: 1.03–3.43 per standard deviation). PF remained associated with CAC even with additional adjustments for estimated glomerular filtration rate or serum phosphorus (OR: 1.85 95% CI: 1.00–3.42, p = 0.05). PF is independently associated with CAC in non-dialysis dependent CKD patients.     

Biomechanical Characteristics of Osteoporotic Fracture Healing in Ovariectomized Rats: A Systematic Review

Biomechanical tests are widely used in animal studies on osteoporotic fracture healing. However, the biomechanical recovery process is still unknown, leading to difficulty in choosing time points for biomechanical tests and in correctly assessing osteoporotic fracture healing. To determine the biomechanical recovery process during osteoporotic fracture healing, studies on osteoporotic femur fracture healing with biomechanical tests in ovariectomized rat (OVX) models were collected from PUBMED, EMBASE, and Chinese databases. Quadratic curves of fracture healing time and maximum load were fitted with data from the analyzed studies. In the fitted curve for normal fractures, the predicted maximum load was 145.56 N, and the fracture healing time was 88.0 d. In the fitted curve for osteoporotic fractures, the predicted maximum load was 122.30 N, and the fracture healing time was 95.2 d. The maximum load of fractured femurs in OVX rats was also lower than that in sham rats at day 84 post-fracture (D84 PF). The fracture healing time was prolonged and maximum load at D84 PF decreased in OVX rats with closed fractures. The maximum load of Wister rats was higher than that of Sprague-Dawley (SD) rats, but the fracture healing time of SD and Wister rats was similar. Osteoporotic fracture healing was delayed in rats that were < = 12 weeks old when ovariectomized, and at D84 PF, the maximum load of rats < = 12 weeks old at ovariectomy was lower than that of rats >12 weeks old at ovariectomy. There was no significant difference in maximum load at D84 PF between rats with an osteoporosis modeling time <12 weeks and > = 12 weeks. In conclusion, fracture healing was delayed and biomechanical property decreased by osteoporosis. Time points around D95.2 PF should be considered for biomechanical tests of osteoporotic femur fracture healing in OVX rat models. Osteoporotic fracture healing in OVX rats was affected by the fracture type but not by the strain of the rat.