Correlation of 18F-sodium fluoride uptake and radiodensity in extraosseous metastases of medullary thyroid carcinoma

Objective

Although 18F-sodium fluoride (18F-NaF) uptake is frequently observed in extraosseous metastases of medullary thyroid carcinoma (MTC) with calcification, itcan also occur in metastatic sites without visible calcium deposition, leading to the hypothesis that visually undetectable calcium accumulation may be responsible for this uptake. The aim of this study was to indirectly support this hypothesis by analyzing the correlation between the degree of 18F-NaF uptake and radiodensity in extraosseous MTC metastases, since calcium deposition can increase attenuation even when not visually detectable.

Subjects and methods

Extraosseous metastatic lesions of 15 patients with MTC were evaluated using 18F-NaF positron-emission tomography (PET)/computed tomography (CT)and segmented by levels of standardized uptake value (SUV). The correlation between mean SUV and mean Hounsfield unit (HU) values was assessed for the entire group of segments and for two subgroups with different mean HU values.

Results

Very high correlations were observed between mean SUV and mean HU values for both the entire group of segments and the subgroup with a mean HU value greater than 130 (p = 0.92 and p = 0.95, respectively; p < 0.01). High correlation (p = 0.71) was also observed in the subgroup with mean HU values ranging from 20 to 130 (p < 0.01).

Conclusion

The findings of the present study suggest that there is an association between 18F-NaF uptake and calcium deposition in extraosseous metastasesof MTC, supporting the hypothesis that visually undetectable calcium accumulation may be responsible for 18F-NaF uptake in regions without visible calcium deposition.

Fluoride, pH Value, and Titratable Acidity of Commercially Available Mouthwashes

AIM

The primary objective of this work was to assess total soluble fluoride (TSF), pH values, and titratable acidity (TA) of various mouthwashes "in vitro," and the second was to compare fluoride content on labels with measured TSF.

METHODS

Commercial mouthwashes were collected and analysed. Company, type, manufacturer data, and active ingredients (essential oils [EO], cetylpyridinium chloride [CPC], chlorhexidine [CHX], and fluoride) were described. TSF, pH, and TA capacity were measured. Descriptive quantitative analysis were performed per mouthwash.

RESULTS

In total, 54 mouthwashes from 20 brands were included. These included mouthwashes with the active ingredients EO (n = 11), CPC (n = 17), CHX (n = 18), and fluoride (n = 32); 27 mouthwashes with more than 1 of these active ingredients; and 4 with none of the above-mentioned ingredients. Fluoride was present in different formulations; most contained sodium fluoride (NaF), and a few had sodium monofluorophosphate and amine fluoride + NaF. The pH values of all evaluated mouthwashes ranged from 4.1 to 7.9. Twenty mouthwashes presented pHs below 5.5, of which 10 contained fluoride. TA ranged from 0 to 48. According to the manufacturer data, mouthwashes with fluoride had concentrations from 217 to 450 ppm, with 90% in the range from 217 to 254 ppm. Laboratory data revealed that TSF ranged from 229 to 500 ppm, with 90% in the range from 229 to 337 ppm. A statistically significant difference was observed between measured TSF and the labelled fluoride content on the packaging of the fluoride mouthwashes (mean difference, 43.92 ± 34.34; P < .001). Most of these mouthwashes contained at least the amount of fluoride as mentioned on the packaging (93%).

CONCLUSION

The pH values and TA of commercially available mouthwashes showed a large variation. TSF levels of the fluoride mouthwashes were found to be at least the amount of fluoride as labelled. Dental care professionals should be aware of the pH, TA, fluoride content, and other active ingredients of different mouthwashes to better understand their potential impact on oral health.

Precise glucose measurement in sodium fluoride-citrate plasma affects estimates of prevalence in diabetes and prediabetes

OBJECTIVES

Estimates of glucose concentrations vary among types of blood samples, which impact on the assessment of diabetes prevalence. Guidelines recommend a conversion factor to calculate plasma glucose from measurements of glucose in whole blood. The American Diabetes Association recommends the use of blood drawing tubes containing sodium fluoride (NaF) and citrate, which have not yet been evaluated regarding possible differences in glucose concentration and conversion factors. Thus, we compared glucose measurements in NaF-citrate plasma and venous whole blood and estimated the impact of differences on diabetes and prediabetes prevalence.

METHODS

Glucose differences were calculated by Bland-Altman analysis with pairwise comparison of glucose measurements from whole blood and NaF-citrate plasma (n=578) in clinical studies of the German Diabetes Center. Subsequently, we computed the impact of the glucose difference on diabetes and prediabetes prevalence in the population-based National Health and Nutrition Examination Survey (NHANES).

RESULTS

Even upon conversion of whole blood to plasma glucose concentrations using the recommended conversion factor, mean glucose concentration difference remained 4.72 % higher in NaF-citrate plasma. Applying the higher glucose estimates, increases the population-based diabetes and prediabetes prevalence by 13.67 and 33.97 % or more than 7.2 and 13 million people in NHANES, respectively. Additional economic burden could be about 20 $ billion per year due to undiagnosed diabetes.

CONCLUSIONS

The recommended conversion factor is not valid for NaF-citrate plasma. Systematic bias of glucose measurements due to sampling type leads to clinically relevant higher estimates of diabetes and prediabetes prevalence.

Stability of diazepam's phase II metabolites in dried blood spots on filter paper

Phase II metabolites play an important role in diazepam-related cases. The study aimed to assess the stability of diazepam's phase II metabolites in dried blood spots on filter paper.

METHODS

A piece of filter paper was spotted with 100 µL of whole blood (added 1% sodium fluoride as needed) obtained from participant who received 5 mg diazepam orally, air dried for 2 h at room temperature, and then stored at different conditions. Whole spots were cut at 0.1 cm from the outer edge of blood spots at post-consumption time-points of prior (zero), 5, 16, 35, 61, 120 days and 1, 1.5 years. Analytes were extracted with methanol/water mixture (8:2, v/v) and determined using HPLC-MS/MS. Decomposition rules were analyzed by a statistical software "SPSS".

RESULTS

Temazepam glucuronide remained stable (0.5-18.6% loss) at 20 ℃ and at 20 ℃ with 1% sodium fluoride for 16 days, while it was unstable after 5 days at 4 ℃ (21.1-26.2% loss) and - 20 ℃ (28.9 - 34.4% loss). After 35 days, temazepam glucuronide concentrations began to fluctuate significantly under all conditions, and an obvious increase (290.4-355.1%) was observed in 1.5 years. Oxazepam glucuronide was always unstable after 5 days, the percentage loss was even 100% when it was stored for 61 days and 1.5 years.

CONCLUSIONS

Dried blood spots on ordinary filter paper are recommended to be stored at 20 ℃ or 20 ℃ with 1% sodium fluoride within 16 days. Samples should be analyzed immediately or stored in sterile and dry media.

Imaging of Rotator Cuff Calcific Tendinopathy Using 18 F-NaF and 18 F-FDG PET/CT

ABSTRACT

Calcific tendinopathy is a common condition of the shoulder caused by the inflammation and deposition of hydroxyapatite crystals in the rotator cuff tendons. PET tracers capturing the molecular changes associated with the crystal deposition of calcific tendinopathy remain underinvestigated. In this report, we present calcified tendinopathy of the infraspinatus tendon demonstrating both 18 F-NaF and 18 F-FDG focal uptake in a 61-year-old woman.

Quantification of Skeletal Muscle Perfusion in Peripheral Artery Disease Using 18F-Sodium Fluoride Positron Emission Tomography Imaging

BACKGROUND

Perfusion deficits contribute to symptom severity, morbidity, and death in peripheral artery disease (PAD); however, no standard method for quantifying absolute measures of skeletal muscle perfusion exists. This study sought to preclinically test and clinically translate a positron emission tomography (PET) imaging approach using an atherosclerosis-targeted radionuclide, fluorine-18-sodium fluoride (18F-NaF), to quantify absolute perfusion in PAD.

METHODS AND RESULTS

Eight Yorkshire pigs underwent unilateral femoral artery ligation and dynamic 18F-NaF PET/computed tomography imaging on the day of and 2 weeks after occlusion. Following 2-week imaging, calf muscles were harvested to quantify microvascular density. PET methodology was validated with microspheres in 4 additional pig studies and translated to patients with PAD (n=39) to quantify differences in calf perfusion across clinical symptoms/stages and perfusion responses in a case of revascularization. Associations between PET perfusion, ankle-brachial index, toe-brachial index, and toe pressure were assessed in relation to symptoms. 18F-NaF PET/computed tomography quantified significant deficits in calf perfusion in pigs following arterial occlusion and perfusion recovery 2 weeks after occlusion that coincided with increased muscle microvascular density. Additional studies confirmed that PET-derived perfusion measures agreed with microsphere-derived perfusion measures. Translation of imaging methods demonstrated significant decreases in calf perfusion with increasing severity of PAD and quantified perfusion responses to revascularization. Perfusion measures were also significantly associated with symptom severity, whereas traditional hemodynamic measures were not.

CONCLUSIONS

18F-NaF PET imaging quantifies perfusion deficits that correspond to clinical stages of PAD and represents a novel perfusion imaging strategy that could be partnered with atherosclerosis-targeted 18F-NaF PET imaging using a single radioisotope injection.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03622359.

Longitudinal imaging of murine atherosclerosis with 2-deoxy-2-[18F]fluoro-D-glucose and [18F]-sodium fluoride in genetically modified Apolipoprotein E knock-out and wild type mice

In a longitudinal design, four arterial segments in mice were followed by positron emission tomography/computed tomography (PET/CT) imaging. We aimed to determine how the tracers reflected the development of atherosclerosis via the uptake of 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) for imaging inflammation and [18F]-sodium fluoride (Na[18F]F) for imaging active microcalcification in a murine model of atherosclerosis. Apolipoprotein E knock-out (ApoE) mice and C57 BL/6NtaC (B6) mice were divided into four groups. They received either normal chow (N = 7, ApoE mice and N = 6, B6 mice) for 32 weeks or a high-fat diet (N = 6, ApoEHFD mice and N = 9, B6HFD mice) for 32 weeks. The mice were scanned with [18F]FDG and Na[18F]F using a dedicated small animal PET/CT scanner at three timepoints. The tracer uptakes in four aortic segments (abdominal aorta, aortic arch, ascending aorta, and thoracic aorta) were measured and reported as SUVmax values. The uptake of [18F]FDG (SUVmax: 5.7 ± 0.5 vs 1.9 ± 0.2, 230.3%, p =  < 0.0001) and Na[18F]F (SUVmax: 9.6 ± 1.8 vs 4.0 ± 0.3, 175%, p = 0.007) was significantly increased in the abdominal aorta of ApoEHFD mice at Week 32 compared to baseline abdominal aorta values of ApoEHFD mice. [18F]FDG uptake in the aortic arch, ascending aorta and the thoracic aorta of B6HFD mice at Week 32 showed a robust resemblance to the abdominal aorta uptake whereas the Na[18F]F uptake only resembled in the thoracic aorta of B6HFD mice at Week 32 compared to the abdominal aorta. The uptake of both [18F]FDG and Na[18F]F increased as the disease progressed over time, and the abdominal aorta provided a robust measure across mouse strain and diet. Therefore, it seems to be the preferred region for image readout. For [18F]FDG-PET, both B6 and ApoE mice provide valuable information and either mouse strain may be used in preclinical cardiovascular studies, whereas for Na[18F]F -PET, ApoE mice should be preferred.

The potential of galactomannan from Caesalpinia ferrea on erosive dentin wear reduction in vitro

Gels containing juca seed galactomannan (JSG) were evaluated for their potential to prevent the progression of dentin erosive wear in an in vitro study with four experimental groups (n = 9). The treatments included distilled water (DW), 0.05% stannous fluoride (121 ppm F), and 0.5% or 1% JSG. The specimens underwent a cycle (3 times/day) consisting of immersion in 1% citric acid (5 minutes), treatment (5 minutes), and artificial saliva exposure (2 hours/overnight) for 5 days. Surface changes were assessed using mechanical profilometry (wear), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The data were analyzed using ANOVA followed by Tukey's post-test (p < 0.05). The negative control group exhibited the highest wear (6.0 µm ± 3.5), significantly differing from the group treated with 0.05% stannous fluoride gel (p = 0.007), which showed less dentin loss. The groups treated with 0.5% and 1% JSG showed results similar to the negative control (p = 0.661; p = 0.212, respectively) and the stannous fluoride group (p = 0.103; p = 0.379, respectively). In the SEM images, the specimen treated with stannous fluoride showed obliterated tubules, while the JSG gels formed crystals on the dentin surface, as confirmed by the presence of oxygen and calcium in the EDS analysis. Although the JSG gels showed similar results to the stannous fluoride, did not exhibit superior efficacy at the tested concentrations.

18F-fluorodeoxyglucose and 18F-sodium fluoride positron emission tomography imaging in assessing early stages of aortic valve degeneration after transcatheter aortic valve implantation

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is a standard treatment for severe aortic stenosis, primarily in elderly patients. With an increasing number of procedures and younger patients, understanding the valve degeneration and its risk factors becomes crucial.

OBJECTIVES

We aimed to utilize 18F‑sodium fluoride (18F‑NaF) and 18F‑fluorodeoxyglucose (18F‑FDG) positron emission tomography/computed tomography (PET/CT) to evaluate early TAVI valve degeneration.

PATIENTS AND METHODS

In this prospective study with a prespecified follow‑up protocol, 71 TAVI patients underwent baseline transthoracic and transesophageal echocardiography, and PET/CT with 18F‑NaF and 18F‑FDG. Of these, 31 patients completed 24‑month control examinations, while the others were lost to mortality and the COVID‑19 pandemic. We measured PET tracer activity and compared 18F‑NaF and 18F‑FDG PET/CT uptake at baseline and 24‑month follow‑up.

RESULTS

PET/CT and echocardiography data were analyzed for 31 of the 71 enrolled TAVI patients at a median age of 84 years (interquartile range, 80-86). After TAVI, an improvement in the valve function was observed. During follow‑up, the valve function remained stable. PET/CT demonstrated an increase in 18F‑FDG maximal uptake in the inner (tissue‑to‑background ratio, P = 0.009) and outer (P = 0.01) sides of the TAVI valve stent, but no difference in 18F‑NaF maximal activity (inner, P = 0.17; outer, P = 0.57).

CONCLUSIONS

Twenty‑four months post‑TAVI, an increase in 18F‑FDG uptake, indicative of inflammation, was observed in the valve, while the uptake of the calcification marker (18F‑NaF) remained stable. Theseobservations might suggest early stages of TAVI valve degeneration, although further investigation is required to confirm this interpretation.

Impact of chitosan-incorporated toothpaste on roughness, gloss, and antifungal potential of acrylic resin

This study aimed to test the efficacy of different silica-based toothpastes with or without chitosan, as a method of cleaning the acrylic surfaces of denture prostheses. Acrylic resin specimens were prepared to evaluate surface roughness and gloss (n = 10), and Candida albicans adhesion/inhibition (n = 2). Two toothpastes with different degrees of abrasiveness were used: Colgate (CT) and Elmex (EX), with or without 0.5% chitosan (Ch) microparticles (CTCh or EXCh, respectively). The negative control was brushed with distilled water. Brushing was simulated with a machine. Surface roughness and gloss were analyzed before and after brushing. Candida albicans incidence/inhibition was tested qualitatively to determine the acrylic resin antifungal activity. The roughness and gloss data were analyzed with a generalized linear model, and the Kruskal Wallis and Dunn tests, respectively (α = 5%). Brushing with toothpastes increased roughness and reduced gloss, compared with the negative control (p < 0.05). CT showed a more significantly different change in roughness and gloss, in relation to the other groups (p < 0.05). Addition of chitosan to CT reduced its abrasive potential, and yielded results similar to those of EX and EXCh. Specimens brushed with CT showed a higher potential for Candida albicans adherence, despite its higher antifungal action. Addition of chitosan to the toothpaste made both toothpaste and brushing more effective in inhibiting Candida albicans. CT had the potential to increase roughness, reduce gloss, and increase Candida albicans adherence. In contrast, chitosan added to CT showed greater antifungal potential, and a higher synergistic effect than EX.

Simultaneous Uptake of 18 F-NaF and 18 F-FDG by Bladder and Prostate Calculi

ABSTRACT

Calcification and formation of calculi in the genitourinary system such as the bladder, kidney, and prostate are common processes of aging. Despite being in different parts of the body, these calculi can share risk factors; for instance, bladder and prostate calculi are seen in older men with benign prostatic hyperplasia. There have been increasing reports of detection of calculi using PET tracers such as 18 F-NaF and 18 F-FDG, suggesting their role for detection of extraosseous calcification. In this report, we present simultaneous detection of bladder and prostate calculi with both 18 F-NaF and 18 F-FDG avidity in a 74-year-old man with multiple myeloma.

Role of 18F-NaF PET/CT in bone metastases

The use of 18F sodium fluoride (18F-NaF) in positron emission tomography (PET/CT) is increasing. This resurgence of an old tracer has been driven by several factors, including its superior diagnostic performance over standard 99mTc-based bone scintigraphy (BS), availability of PET/CT imaging systems, a shortened examination time and an increase in the number of regional commercial PET radiotracer distribution. In this special article, we aimed to highlight the current place of the 18F-NaF PET/CT in the imaging of bone metastases (BM) in a variety of malignancies. A special focus is given to the following ones: breast cancer (BC), prostate cancer (PCa). Also, other malignancies such as bladder cancer, lung cancer, thyroid cancer, multiple myeloma, head and neck cancer, hepatocellular carcinoma have been addressed. At last, we summarize the advantages and limits of the 18F-NaF PET/CT compared to other imaging modalities in these settings.

18F-sodium fluoride positron emission tomography following coronary computed tomography angiography in predicting long-term coronary events: a 5-year follow-up study

PURPOSE

The predictive value of 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) in combination with coronary computed tomography (CT) angiography (CCTA) for future coronary events has attracted interest. We evaluated the potential of 18F-NaF PET/CT following CCTA to predict major coronary events (MACE) during a 5-year follow-up period.

METHODS

Forty patients with coronary atherosclerotic lesions detected on CCTA underwent 18F-NaF PET/CT examination. Each lesion was evaluated for luminal stenosis and high-risk plaque (HRP) with < 30 Hounsfield units and a > 1.1 remodeling index on CCTA. Focal 18F-NaF uptake in each lesion was quantified using the maximum tissue-to-background ratio (TBRmax), and the maximum TBRmax per patient (M-TBRmax) was determined. We followed MACE (cardiac death, acute coronary syndrome, and/or coronary revascularization > 6 months after 18F-NaF PET/CT) for 5 years.

RESULTS

In total, 142 coronary lesions were analyzed. Eleven patients experienced any MACE. Patients with MACE showed a higher M-TBRmax than those without (1.40 ± .19 vs. 1.18 ± .18, P = .0011), and the optimal M-TBRmax cutoff to predict MACE was 1.29. Patients with M-TBRmax of ≥ 1.29 had a higher risk of MACE than those with lower values (P = .012, log-rank test), whereas patients with obstructive stenosis and those with HRP did not. Multivariate Cox proportional analysis adjusted for age, sex, coronary risk factors, and CCTA findings showed that M-TBRmax of ≥ 1.29 remained an independent predictor of 5-year MACE (hazard ratio, 5.4; 95% confidence interval, 1.1-25.4; P = .034).

CONCLUSION

18F-NaF PET/CT following CCTA provides useful strategies to predict 5-year MACE.

Osteopontin Activation and Microcalcification in Venous Grafts Can Be Modulated by Dexamethasone

BACKGROUND

Osteopontin has been implicated in vascular calcification formation and vein graft intimal hyperplasia, and its expression can be triggered by pro-inflammatory activation of cells. The role of osteopontin and the temporal formation of microcalcification in vein grafts is poorly understood with a lack of understanding of the interaction between haemodynamic changes and the activation of osteopontin.

METHODS

We used a porcine model of vein interposition grafts, and human long saphenous veins exposed to ex vivo perfusion, to study the activation of osteopontin using polymerase chain reaction, immunostaining, and 18F-sodium fluoride autoradiography.

RESULTS

The porcine model showed that osteopontin is active in grafts within 1 week following surgery and demonstrated the presence of microcalcification. A brief pretreatment of long saphenous veins with dexamethasone can suppress osteopontin activation. Prolonged culture of veins after exposure to acute arterial haemodynamics resulted in the formation of microcalcification but this was suppressed by pretreatment with dexamethasone. 18F-sodium fluoride uptake was significantly increased as early as 1 week in both models, and the pretreatment of long saphenous veins with dexamethasone was able to abolish its uptake.

CONCLUSIONS

Osteopontin is activated in vein grafts and is associated with microcalcification formation. A brief pretreatment of veins ex vivo with dexamethasone can suppress its activation and associated microcalcification.

Fluorotic Enamel Susceptibility to Dental Erosion and Fluoride Treatment

The purpose of this in vitro study was to test the hypothesis that fluoride treatment can prevent dental erosion on fluorotic enamel of different severities. It followed a 3×2 factorial design, considering a) fluorosis severity: sound (TF0, Thylstrup-Fejerskov Index), mild (TF1-2), moderate (TF3-4); and b) fluoride treatment: 0 (negative control) and 1150ppmF. Human molars with the three fluorosis severities (n=16, each) were selected and randomly assigned to the two fluoride treatments (n=8). Enamel blocks (4×4mm) were prepared from each tooth and subjected to a dental erosion cycling model, for 10 days. The daily cycling protocol consisted of erosive challenges (1% citric acid, pH 2.4), interspersed by periods of immersion in artificial saliva, and three 2-minute treatments with either 0 or 1150ppm F. The enamel volume loss (mm3) was calculated by subtracting values obtained by microtomography before and after cycling. Two-Way ANOVA showed no significant interaction between fluorosis severity and fluoride treatment (p=0.691), and no significant effect for either fluorosis severity (TF0 mean±standard-deviation: 13.5(10-2±0.42(10-2, TF1-2: 1.50(10-2±0.52(10-2, TF3-4: 1.24(10-2±0.52(10-2, p=0.416) or treatment (0ppmF: 1.49(10-2±0.53(10-2; 1150ppmF: 1.21(10-2±0.42(10-2; p=0.093), when evaluated independently. Considering the limitations of this in vitro study, the presence and severity of fluorosis in enamel do not appear to affect its susceptibility to dental erosion. Fluoride treatment was not effective in preventing the development of dental erosion in both sound and fluorotic enamel substrates under our experimental conditions.

18F-sodium fluoride positron emission tomography provides pertinent additional information to computed tomography for assessment and management of tarsal pain in horses

OBJECTIVE

To assess the value of 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) for imaging the tarsus and proximal metatarsus and compare it with CT and lameness evaluation.

ANIMALS

25 horses with lameness localized to the tarsal and proximal metatarsal regions that underwent 18F-NaF PET/CT between 2016 and 2021.

METHODS

18F-NaF PET and CT images were retrospectively independently evaluated by 3 observers. Standardized uptake values (SUV) were used to characterize 18F-NaF uptake. Correlation between PET and CT findings with subjective and objective maximum (Max-D) and minimum pelvic height lameness data was estimated.

RESULTS

The inter-observer Kappa-weighted value (κ) was higher for PET (κ = 0.66) than CT (κ = 0.6). CT and PET scores were fairly correlated (R = 0.49; P < 0.05). PET SUVratio (SUV of the main lesion/SUV talus) had the highest correlation with Max-D (R = 0.71; P < .05). PET and CT scores for the plantar region were significantly higher in Quarter Horses (P < .05) and showed consistently higher correlation with objective lameness data (CT plantar grade - Max-D [R = 0.6; P < .05], PET plantar grade - Max-D [R = 0.47; P = .04]) than other regions of the distal tarsal joints. Three Warmbloods presented marked uptake at the medial cochlea of the distal tibia.

CLINICAL RELEVANCE

PET had a moderate correlation with CT for assessment of tarsal lesions. The degree of PET uptake can help differentiate active versus inactive lesions. Specific location of the uptake is important in determining clinical relevance.

Evaluation of the long-term stability of select phenylacetylindole, cycloalkylindole, quinolinyl, and carboxamide synthetic cannabinoids using LC-MS-MS

Forensic toxicology laboratories often encounter casework backlogs, which raise concerns for drug stability that can be affected by long storage times, temperature and preservatives, or the lack thereof. The focus of this research was to evaluate the impact of these factors on the stability of 17 synthetic cannabinoids (SCs) in human whole blood and 10 associated metabolites in human urine. The fortified biological specimens were stored under room temperature (20°C), refrigerator (4°C) and freezer (-20°C) conditions for a period of 52 weeks. Preservatives included potassium oxalate, sodium ethylenediaminetetraacetic acid and sodium fluoride. Extraction of analytes was conducted using supported liquid extraction and analyzed using a liquid chromatograph-tandem mass spectrometer. Under all three storage conditions, the majority of urine metabolites were stable up to 9 weeks. All analytes in frozen sodium fluoride-preserved blood were stable at 21-52 weeks with the exception of APP-PICA. Analytes in the blood that were stable up to 52 weeks in the freezer generally had a core structure of a carbonyl substituent on a pyrazole or pyrrole with surrounding nonpolar groups. In contrast, compounds with two adjacent polar carbonyl functional groups experienced degradation at ≤1 week under ambient temperature and refrigeration. 5-Fluoropentyl analogs, XLR11 and 5-fluoro ADB-PINACA, in comparison to their counterpart analytes, UR144 and ADB-PINACA, were unstable at earlier time points under all temperatures. Based on these data, forensic blood evidence suggesting the presence of SC compounds is recommended to be frozen with sodium fluoride and potassium oxalate preservatives for optimal quantitative results.

Viability of bacteria associated with root caries after Nd:YAG laser application in combination with various antimicrobial agents: An in vitro study

BACKGROUND

The neodymium-doped yttrium aluminum garnet (Nd:YAG) laser has various therapeutic applications in dentistry, including the treatment of dentin hypersensitivity and the bacterial reduction therapy in periodontology. The addition of antimicrobial agents may enhance the impact of the laser on bacterial viability.

OBJECTIVES

This in vitro study aimed to assess the effect of Nd:YAG laser application in combination with various chemical antimicrobial agents, including hydrogen peroxide (H2O2), sodium hypochlorite (NaOCl), chlorhexidine (CHX), and sodium fluoride (NaF), on the viability of bacteria implicated in the etiology of root caries.

MATERIAL AND METHODS

Three oral bacterial species were examined: Streptococcus mutans (S. mutans); Streptococcus sanguinis (S. sanguinis); and Enterococcus faecalis (E. faecalis). The bacteria were grown in broth at 37°C, and then treated with the chemical agents and/or irradiated with an Nd:YAG laser for 30 s. Each treatment modality was repeated 3 times: group 1 - no treatment; group 2 - 0.5% H2O2; group 3 - 0.5% NaOCl; group 4 - 0.12% CHX; group 5 - 2% NaF; group 6 - Nd:YAG laser irradiation; group 7 - laser and 0.5% H2O2; group 8 - laser and 0.5% NaOCl; group 9 - laser and 0.12% CHX; and group 10 - laser and 2% NaF. The viability of the bacteria was determined by plating them, counting viable colonies, converting the data into colony-forming units (CFUs)/mL, and transforming them into the log form. Statistical analysis was performed using the two-tailed paired t test.

RESULTS

Irradiation with an Nd:YAG laser alone did not show a statistically significant effect against any of the bacterial species. The only effective antimicrobial used alone was CHX for S. mutans. Chlorhexidine with Nd:YAG resulted in a greater reduction in S. mutans and E. faecalis than either treatment alone. Meanwhile, H2O2 with Nd:YAG also showed an enhanced S. mutans reduction. Treatment with 0.5% NaOCl in conjunction with Nd:YAG brought the most significant reduction in viability for all bacteria in comparison with other treatment modalities.

CONCLUSIONS

The Nd:YAG laser combined with 0.5% NaOCl resulted in the most substantial reduction in bacterial survival as compared to the antimicrobials or the Nd:YAG laser used alone.

Comparisons of blood alcohol concentrations between initial testing and reanalysis from unopened tubes preserved with 0.25% NaF following refrigerated storage up to 3.93 years

Few studies support the usage of <1% nominal sodium fluoride (NaF) to preserve ethanol in antemortem blood. Of these studies, several are limited by short study durations of 90 days or less, and there is limited research of authentic samples preserved with <1% NaF. In this retrospective analysis, data from initial and reanalysis testing of blood alcohol concentration (BAC) in antemortem blood collected in 6 mL gray-top tubes (providing 0.25% nominal NaF) has been compiled, to evaluate changes in ethanol concentration that occurred after periods of refrigerated storage. The time between initial and reanalysis was determined by court request(s), and ranged 0.30-3.93 years. In each case, a previously unopened tube was selected for reanalysis testing. Comparable BAC values were found from initial testing, with BACs ranging from 0.025 to 0.394 g/100 mL, and reanalysis testing, with BACs ranging from 0.021 to 0.393 g/100 mL. Ethanol changes ranged from -0.013 g/100 mL (decrease) to 0.008 g/100 mL (increase). BAC reanalysis values that increased (n = 6) were within the uncertainty of measurement (UM) from the initial BAC test, that is, were not statistically or analytically significant. For BAC decreases (n = 29), four test values exceeded the UM of the original test, with BAC losses ranging from 0.004 to 0.011 g/100 mL (relative percent changes 6.5-16.0% loss). The average ethanol change was -0.004 g/100 mL, which is comparable to or less than ethanol losses from studies using 1% NaF preservative of varying temperature and storage duration.

Utility of a simplified [18F] sodium fluoride PET imaging method to quantify bone metabolic flux for a wide range of clinical applications

We review the rationale, methodology, and clinical utility of quantitative [18F] sodium fluoride ([18F]NaF) positron emission tomography-computed tomography (PET-CT) imaging to measure bone metabolic flux (Ki, also known as bone plasma clearance), a measurement indicative of the local rate of bone formation at the chosen region of interest. We review the bone remodelling cycle and explain what aspects of bone remodelling are addressed by [18F]NaF PET-CT. We explain how the technique works, what measurements are involved, and what makes [18F]NaF PET-CT a useful tool for the study of bone remodelling. We discuss how these measurements can be simplified without loss of accuracy to make the technique more accessible. Finally, we briefly review some key clinical applications and discuss the potential for future developments. We hope that the simplified method described here will assist in promoting the wider use of the technique.

18 F-sodium fluoride positron emission tomography quantitation of bone metastases in African American and non-African American men with metastatic prostate cancer

BACKGROUND

Bone is the most common site of metastases in men with prostate cancer. The objective of this study was to explore potential racial differences in the distribution of tumor metastases in the axial and appendicular skeleton.

METHODS

We conducted a retrospective review of patients with metastatic prostate cancer to the bone as detected by 18 F-sodium fluoride positron emission tomography/computed tomography (18 F-NaF PET/CT) scans. In addition to describing patients' demographics and clinical characteristics, the metastatic bone lesions, and healthy bone regions were detected and quantified volumetrically using a quantitative imaging platform (TRAQinform IQ, AIQ Solutions).

RESULTS

Forty men met the inclusion criteria with 17 (42%) identifying as African Americans and 23 (58%) identifying as non-African Americans. Most of the patients had axial (skull, ribcage, and spine) disease. The location and the number of lesions in the skeleton of metastatic prostate cancer patients with low disease burden were not different by race.

CONCLUSIONS

In low-disease burden patients with metastatic prostate cancer, there were no overall differences by race in the location and number of lesions in axial or appendicular skeleton. Therefore, given equal access to molecular imaging, African Americans might derive similar benefits. Whether this holds true for patients with a higher disease burden or for other molecular imaging techniques is a topic for further study.

Effect of mouthwashes on the force decay of polymeric ligature chains used for dental purposes: a systematic review and meta-analysis

BACKGROUND

External factors such as the daily use of antimicrobial mouthwashes to maintain oral hygiene and to reduce the microbial activity can contribute to alter the mechanical properties of the elastomeric chains used during orthodontic treatments, causing loss of effectiveness. This systematic review and a meta-analysis assessed the rate of force decay and degradation of the polymeric chains depending on the type of mouthwash.

METHODS

A systematic search of the literature were there was an exposure of orthodontic elastomeric chains to certain mouthwashes was conducted in the electronic databases of PubMed, Cochrane Library (CENTRAL), Scopus, EMBASE and Web of Science, as well as grey literature (Opengrey). No limit was placed on publication year and research was done up to June 2022. Based on inclusion/ exclusion criteria, data were extracted by two independent reviewers. For the quantitative analysis, studies were analysed with a mixed-effect (random effect) meta-regression model, with beta coefficients and R [2] values. I [2] index and Q and Egger tests were used to find heterogeneity among studies.

RESULTS

A total of 178 potentially eligible studies were identified, of which 14 were eventually included in the qualitative analysis and 14 in the quantitative meta-analysis. The meta-analysis showed that all the mouthwashes were associated with a greater force decay than the control groups. After 7 days (p = 0.005) significant differences were found among the different mouthwashes, with those containing alcohol having significantly higher impact on the force decay than those containing chlorhexidine 0.2%, sodium fluoride or Persica. However, at 24 h (p = 0.200), 14 days (p = 0.076), 21 days (p = 0.120) and 28 days (p = 0.778) no statistically significant differences among the different mouthwashes were found, although those containing alcohol presented a strong tendency.

CONCLUSION

Although mouthwashes tend to increase the speed of force decay of elastomeric chains, especially those containing alcohol, clorhexidine 0.2% can be a good alternative due to its low impact on the force decay and its ability to maintain low microbial activity. More in vitro and in vivo studies comparing different manufacturers and other agents should be performed.

Optimization of a Validated Protocol That Determines Bioavailable Fluoride in Toothpastes

A validated protocol used to determine how much of total fluoride is bioavailable in toothpaste formulations was evaluated if it could be simplified regarding the following parameters: (1) concentration of the slurry (0.25-4%), (2) centrifugation speed (1,000-12,000 g) and time (1-10 min), and (3) incubation time for FPO32- ion hydrolysis and insoluble-F dissolution (15-60 min). Fresh and aged Na2FPO3/CaCO3 and fresh NaF/SiO2-based toothpastes were analyzed (n = 9). The improvements were the centrifugation at 1,000 g for 5 min is enough to separate insoluble-F and the time for FPO32- ion hydrolysis and insoluble-F dissolution can be shortened to 30 min.

Salivary fluoride concentrations following toothbrushing with experimental toothpaste containing surface pre-reacted glass-ionomer (S-PRG) filler

BACKGROUND

Single-blind 9 case comparative studies were conducted to evaluate salivary fluoride concentrations following toothbrushing using experimental toothpaste containing surface pre-reacted glass-ionomer (S-PRG) fillers. Preliminary tests were conducted in order to determine the volume of usage as well as the concentrations (wt %) of S-PRG filler. Based on the results given these experiments, we compared the salivary fluoride concentrations following toothbrushing with 0.5 g of 4 different types of toothpastes: 5 wt % S-PRG filler, 1400 ppm F AmF (amine fluoride), 1500 ppm F NaF (sodium fluoride), and MFP (monofluorophosphate) containing toothpaste.

METHODS

Of the 12 participants, 7 participated in the preliminary study and 8 in the main study. All participants brushed their teeth using the scrubbing method for 2 min. At first, 1.0 and 0.5 g of 20 wt % S-PRG filler toothpastes were used to compare, then followed by 0.5 g of 0 (control), 1, and 5 wt % S-PRG toothpastes, respectively. The participants spat out once and rinsed with 15 mL of distilled water for 5 s. Saliva was collected for 3 min each at different time intervals of 0 (baseline), 5, 10, 15, 30, 60, 120, and 180 min after the rinsing. Fluoride concentrations were determined using a fluoride electrode, and the area under the salivary clearance - time curve (AUC: ppm‧min) of each toothpaste was calculated as the salivary fluoride retention. The main study was then conducted to evaluate the salivary fluoride concentrations as well as the AUC value using 0.5 g of 5 wt % S-PRG filler toothpaste, followed by NaF, MFP, and AmF toothpastes.

RESULTS

Since there were no statistical differences between using 1.0 and 0.5 g of 20 wt % S-PRG toothpastes in salivary fluoride concentrations as well as the AUC value throughout the 180 min measurement, the volume was set as 0.5 g for the following studies. Concentrations of 5 and 20 wt % S-PRG toothpastes retained 0.09 ppm F or more in saliva even after 180 min. No statistical differences were seen in the salivary fluoride concentrations at any time intervals as well as the AUC value between 5 and 20 wt % S-PRG toothpastes. Based on these results, the concentration of 5 wt % S-PRG toothpaste was used for the main comparative study. MFP toothpaste resulted in by far the lowest salivary fluoride concentrations (0.06 ppm F at 180 min) and the AUC value (24.6 ppm‧min), whereas 5 wt % S-PRG toothpaste (0.15 ppm F at 180 min, 92.3 ppm‧min) displayed retention on par with AmF toothpaste which appeared to result in higher values (0.17 ppm F at 180 min, 103 ppm‧min), compared to NaF toothpaste (0.12 ppm F at 180 min, 49.3 ppm‧min).

CONCLUSIONS

The salivary fluoride concentrations following toothbrushing with 0.5 g of 5 wt % S-PRG filler containing toothpaste showed retention similar to the best performing 1400 ppm F AmF toothpaste even 180 min after toothbrushing.

Coronary Atherosclerotic Plaque Activity and Future Coronary Events

Importance

Recurrent coronary events in patients with recent myocardial infarction remain a major clinical problem. Noninvasive measures of coronary atherosclerotic disease activity have the potential to identify individuals at greatest risk.

Objective

To assess whether coronary atherosclerotic plaque activity as assessed by noninvasive imaging is associated with recurrent coronary events in patients with myocardial infarction.

Design, Setting, and Participants

This prospective, longitudinal, international multicenter cohort study recruited participants aged 50 years or older with multivessel coronary artery disease and recent (within 21 days) myocardial infarction between September 2015 and February 2020, with a minimum 2 years' follow-up.

Intervention

Coronary 18F-sodium fluoride positron emission tomography and coronary computed tomography angiography.

Main Outcomes and Measures

Total coronary atherosclerotic plaque activity was assessed by 18F-sodium fluoride uptake. The primary end point was cardiac death or nonfatal myocardial infarction but was expanded during study conduct to include unscheduled coronary revascularization due to lower than anticipated primary event rates.

Results

Among 2684 patients screened, 995 were eligible, 712 attended for imaging, and 704 completed an interpretable scan and comprised the study population. The mean (SD) age of participants was 63.8 (8.2) years, and most were male (601 [85%]). Total coronary atherosclerotic plaque activity was identified in 421 participants (60%). After a median follow-up of 4 years (IQR, 3-5 years), 141 participants (20%) experienced the primary end point: 9 had cardiac death, 49 had nonfatal myocardial infarction, and 83 had unscheduled coronary revascularizations. Increased coronary plaque activity was not associated with the primary end point (hazard ratio [HR], 1.25; 95% CI, 0.89-1.76; P = .20) or unscheduled revascularization (HR, 0.98; 95% CI, 0.64-1.49; P = .91) but was associated with the secondary end point of cardiac death or nonfatal myocardial infarction (47 of 421 patients with high plaque activity [11.2%] vs 19 of 283 with low plaque activity [6.7%]; HR, 1.82; 95% CI, 1.07-3.10; P = .03) and all-cause mortality (30 of 421 patients with high plaque activity [7.1%] vs 9 of 283 with low plaque activity [3.2%]; HR, 2.43; 95% CI, 1.15-5.12; P = .02). After adjustment for differences in baseline clinical characteristics, coronary angiography findings, and Global Registry of Acute Coronary Events score, high coronary plaque activity was associated with cardiac death or nonfatal myocardial infarction (HR, 1.76; 95% CI, 1.00-3.10; P = .05) but not with all-cause mortality (HR, 2.01; 95% CI, 0.90-4.49; P = .09).

Conclusions and Relevance

In this cohort study of patients with recent myocardial infarction, coronary atherosclerotic plaque activity was not associated with the primary composite end point. The findings suggest that risk of cardiovascular death or myocardial infarction in patients with elevated plaque activity warrants further research to explore its incremental prognostic implications.

Latent Coronary Plaque Morphology From Computed Tomography Angiography, Molecular Disease Activity on Positron Emission Tomography, and Clinical Outcomes

BACKGROUND

Assessments of coronary disease activity with 18F-sodium fluoride positron emission tomography and radiomics-based precision coronary plaque phenotyping derived from coronary computed tomography angiography may enhance risk stratification in patients with coronary artery disease. We sought to investigate whether the prognostic information provided by these 2 approaches is complementary in the prediction of myocardial infarction.

METHODS

Patients with known coronary artery disease underwent coronary 18F-sodium fluoride positron emission tomography and coronary computed tomography angiography on a hybrid positron emission tomography/computed tomography scanner. Coronary 18F-NaF uptake was determined by the coronary microcalcification activity. We performed quantitative plaque analysis of coronary computed tomography angiography datasets and extracted 1103 radiomic features for each plaque. Using weighted correlation network analysis, we derived latent morphological features of coronary lesions which were aggregated to patient-level radiomics nomograms to predict myocardial infarction.

RESULTS

Among 260 patients with established coronary artery disease (age, 65±9 years; 83% men), 179 (69%) participants showed increased coronary 18F-NaF activity (coronary microcalcification activity>0). Over 53 (40-59) months of follow-up, 18 patients had a myocardial infarction. Using weighted correlation network analysis, we derived 15 distinct eigen radiomic features representing latent morphological coronary plaque patterns in an unsupervised fashion. Following adjustments for calcified, noncalcified, and low-density noncalcified plaque volumes and 18F-NaF coronary microcalcification activity, 4 radiomic features remained independent predictors of myocardial infarction (hazard ratio, 1.46 [95% CI, 1.03-2.08]; P=0.03; hazard ratio, 1.62 [95% CI, 1.04-2.54]; P=0.02; hazard ratio, 1.49 [95% CI, 1.07-2.06]; P=0.01; and hazard ratio, 1.50 (95% CI, 1.05-2.13); P=0.02).

CONCLUSIONS

In patients with established coronary artery disease, latent coronary plaque morphological features, quantitative plaque volumes, and disease activity on 18F-sodium fluoride positron emission tomography are additive predictors of myocardial infarction.

Effect of fluoride gels with nano-sized sodium trimetaphosphate on the in vitro remineralization of caries lesions

OBJECTIVE

To evaluate the effects of fluoride (F) gels supplemented with micrometric or nano-sized sodium trimetaphosphate (TMPmicro and TMPnano, respectively) on the in vitro remineralization of caries-like lesions.

METHODOLOGY

Bovine enamel subsurface lesions (n=168) were selected according to their surface hardness (SH) and randomly divided into seven groups (n=24/group): Placebo (without F/TMP), 4,500 ppm F (4500F), 4500F + 2.5% TMPnano (2.5% Nano), 4500F + 5% TMPnano (5% Nano), 4500F + 5% TMPmicro (5% Micro), 9,000 ppm F (9000F), and 12,300 ppm F (Acid gel). The gels were applied in a thin layer for one minute. Half of the blocks were subjected to pH cycling for six days, whereas the remaining specimens were used for loosely- (calcium fluoride; CaF2) and firmly-bound (fluorapatite; FA) fluoride analysis. The percentage of surface hardness recovery (%SHR), area of subsurface lesion (ΔKHN), CaF2, FA, calcium (Ca), and phosphorus (P) on/in enamel were determined. Data (log10-transformed) were subjected to ANOVA and the Student-Newman-Keuls' test (p<0.05).

RESULTS

We observed a dose-response relation between F concentrations in the gels without TMP for %SHR and ΔKHN. The 2.5% Nano and 5% Micro reached similar %SHR when compared with 9000F and Acid gels. For ΔKHN, Placebo and 5% Nano gels had the highest values, and 5% Micro, 2.5% Nano, 9000F, and Acid gels, the lowest. All groups had similar retained CaF2 values, except for Placebo and Acid gel. We verified observed an increase in Ca concentrations in nano-sized TMP groups. Regarding P, TMP groups showed similar formation and retention to 9000F and Acid.

CONCLUSION

Adding 2.5% nano-sized or 5% micrometric TMP to low-fluoride gels lead to enhanced in vitro remineralization of artificial caries lesions.

A longitudinal pilot study to assess temporal changes in coronary arterial 18F-sodium fluoride uptake

PURPOSE

How coronary arterial 18F-sodium fluoride (18F-NaF) uptake on positron emission tomography changes over the long term and what clinical factors impact the changes remain unclear. We sought to investigate the topics in this study.

METHODS

We retrospectively studied 15 patients with ≥1 coronary atherosclerotic lesion/s detected on cardiac computed tomography who underwent baseline and follow-up (interval of >3 years) 18F-NaF positron emission tomography/computed tomography scans. Focal 18F-NaF uptake in each lesion was quantified using maximum tissue-to-background ratio (TBRmax). The temporal change in TBRmax was assessed using a ratio of follow-up to baseline TBRmax (R-TBRmax).

RESULTS

A total of 51 lesions were analyzed. Mean R-TBRmax was 0.96 ± 0.21. CT-based lesion features (location, obstructive stenosis, plaque types, features of high-risk plaque) did not correlate with an increase in R-TBRmax. In multivariate analysis, baseline TBRmax significantly correlated with higher follow-up TBRmax (β = 0.57, P < 0.0001), and the presence of diabetes mellitus significantly correlated with both higher follow-up TBRmax (β = 0.34, P = 0.001) and elevated R-TBRmax (β = 0.40, P = 0.003).

CONCLUSION

Higher coronary arterial 18F-NaF uptake is likely to remain continuously high. Diabetes mellitus affects the long-term increase in coronary arterial 18F-NaF uptake.

Stability of nafamostat in intravenous infusion solutions, human whole blood and extracted plasma: implications for clinical effectiveness studies

Aim: To describe the stability of nafamostat in infusion solutions, during blood sample collection and in extracted plasma samples in the autosampler. Methods: Nafamostat infusion solutions were stored at room temperature in the light for 24 h. For sample collection stability, fresh blood spiked with nafamostat was subjected to combinations of anticoagulants, added esterase inhibitor and temperature. Nafamostat was monitored in the extracted plasma samples in the autosampler. Results: Nafamostat was stable in infusion solutions. Nafamostat in whole blood was stable for 3 h before centrifugation when collected in sodium fluoride/potassium oxalate tubes (4°C). Nafamostat in extracted plasma samples degraded at 4.7 ± 0.7% per h. Conclusion: Viable samples can be obtained using blood collection tubes with sodium fluoride, chilling and processing promptly.

Evaluation of the efficacy of a charcoal-based tooth whitening dentifrice on coffee stains: an in vitro study

Background

Charcoal-based preparations have recently gained popularity, particularly in oral hygiene products such as tooth whitening dentifrices, owing to their abrasive and adsorptive properties. The present in vitro study evaluates the efficacy of a charcoal-based tooth whitening dentifrice compared with a non-charcoal-based whitening dentifrice in removing coffee stains on tooth surfaces.

Methods

Thirty-three human extracted tooth specimens were randomly assigned to 1 of 3 study groups: Group 1 (charcoal-based whitening dentifrice [CBWD]), Group 2 (non-charcoal-based whitening dentifrice [NCBWD]), and Group 3 (distilled water [DW]). All tooth specimens were immersed in a prepared coffee extract for 4 weeks to facilitate staining and then mounted on blocks where they were brushed with an electric toothbrush daily for 8 seconds with 1 of the 2 allocated dentifrices or with DW for 4 weeks following staining. Spectrophotometric analysis was conducted using the CIELAB system to measure the L*, a*, and b* values at 3 time points: before staining, after staining, and following the brushing protocol. These values were used to calculate the colour change (ΔE) between time points.

Results

Following the coffee staining, the tooth samples' whiteness (ΔL) decreased with the overall colour change (ΔE). Next, there was a significant improvement in the degree of tooth whiteness (ΔL) values following the brushing protocol in all 3 groups (p = 0.003), with the greatest improvement occurring in the CBWD group. However, the overall colour change (ΔE) was not significantly different between the groups.

Conclusion

CBWD, NCBWD, and DW were effective in removing coffee stains from the tooth surface. However, the amount of colour change (ΔE) produced by CBWD was not significantly different from NCBWD or DW.

Automated nonlinear registration of coronary PET to CT angiography using pseudo-CT generated from PET with generative adversarial networks

BACKGROUND

Coronary 18F-sodium-fluoride (18F-NaF) positron emission tomography (PET) showed promise in imaging coronary artery disease activity. Currently image processing remains subjective due to the need for manual registration of PET and computed tomography (CT) angiography data. We aimed to develop a novel fully automated method to register coronary 18F-NaF PET to CT angiography using pseudo-CT generated by generative adversarial networks (GAN).

METHODS

A total of 169 patients, 139 in the training and 30 in the testing sets were considered for generation of pseudo-CT from non-attenuation corrected (NAC) PET using GAN. Non-rigid registration was used to register pseudo-CT to CT angiography and the resulting transformation was used to align PET with CT angiography. We compared translations, maximal standard uptake value (SUVmax) and target to background ratio (TBRmax) at the location of plaques, obtained after observer and automated alignment.

RESULTS

Automatic end-to-end registration was performed for 30 patients with 88 coronary vessels and took 27.5 seconds per patient. Difference in displacement motion vectors between GAN-based and observer-based registration in the x-, y-, and z-directions was 0.8 ± 3.0, 0.7 ± 3.0, and 1.7 ± 3.9 mm, respectively. TBRmax had a coefficient of repeatability (CR) of 0.31, mean bias of 0.03 and narrow limits of agreement (LOA) (95% LOA: - 0.29 to 0.33). SUVmax had CR of 0.26, mean bias of 0 and narrow LOA (95% LOA: - 0.26 to 0.26).

CONCLUSION

Pseudo-CT generated by GAN are perfectly registered to PET can be used to facilitate quick and fully automated registration of PET and CT angiography.

Corrosion of copper nickel titanium archwire in chlorhexidine, sodium fluoride, and chitosan mouthwashes

Background: Copper (Cu), nickel (Ni), chromium (Cr) ion release, and surface topography change from the orthodontic wire are the initial processes of corrosion that may affect the mechanical properties of the archwire. In this study, we aim to evaluate the effect of CHX, NaF, and chitosan on the corrosion of CuNiTi wire nickel and copper ions released, surface roughness change, and archwire deflection. Methods: Ninety samples of CuNiTi Tanzo™ archwires were divided into five groups according to their immersion solution: Artificial Saliva, CHX, NaF, CHX-NaF, and chitosan group. Each group was further divided into three subgroups (n=6) corresponding immersion time, i.e., two, four, and six weeks. The corrosion of the samples was analyzed with an atomic absorption spectrophotometer (AAS), scanning electron microscope (SEM), and universal testing machine (UTM). Results: The amount of nickel ion releases was increasing, but the copper ion releases were reduced by the time of observations. The highest nickel ion was released in the CHX-NaF group and the lowest in the chitosan group for six-week immersion. It also corresponded to the surface topography by SEM analysis which showed the most extended cracks and deep pits in the CHX-NaF group and a smoother surface in the chitosan group. Copper ion release showed the highest ion release in the NaF group and the lowest release in the chitosan group. The unloading force of CuNiTi archwire deflection remains the same at week two and week four for all mouthwashes. Conclusion: The use of mouthwashes that contained CHX, NaF, and chitosan could further alter the passive layer and cause higher nickel and copper ion release and increased CuNiTi archwire surface structure porosity. But there is no distinction between mouthwashes to release the unloading force within two until four weeks.

Inhibition of autophagy reduces the rate of fluoride-induced LS8 apoptosis via regulating ATG5 and ATG7

Excessive fluoride affects ameloblast differentiation and tooth development. The fate of fluorinated ameloblasts is determined by multiple signaling pathways in response to a range of stimuli. Both autophagy and apoptosis are involved in the regulation of dental fluorosis as well as in protein synthesis and enamel mineralization. Emerging evidence suggests that autophagy and apoptosis are interconnected and that their interaction greatly influences cell death. However, the effect of autophagy on apoptosis in fluoride-treated ameloblasts is unclear. Here, we employed an in vitro cellular model of fluorosis in mouse ameloblast-like LS8 cells and induced autophagy using sodium fluoride (NaF). Our findings suggest that NaF treatment induces autophagy in LS8 cells, and ATG5 and ATG7 are important molecules involved in this process. We also showed that NaF treatment reduced cell viability in Atg5/7 siRNA and autophagy inhibitor-treated LS8 cells. More importantly, NaF-induced apoptosis can be reversed by inhibiting early stage of autophagy. In conclusion, our study shows that autophagy is closely related to dental fluorosis, and inhibition of autophagy, especially ATG5/7, reduces fluoride-induced cell death and apoptosis.

Integrated 16S rDNA sequencing and metabolomics to explore the intestinal changes in children and rats with dental fluorosis

Dental fluorosis (DF) is a widely prevalent disease caused by excessive fluoride with limited awareness of its underlying pathogenesis. Here, a pilot population study was conducted to explore the pathogenesis of DF from the perspective of intestinal microbiome changes, and verified it in animal experiments combining intestinal microbiome and metabolomics. A total of 23 children were recruited in 2017 in China and divided into DF (n = 9) and control (n = 14) groups (DFG and CG, respectively). The SD rat model was established by drinking water containing sodium fluoride (NaF). Gut microbiome profiles of children and rats were analyzed by16S rDNA V3-V4 sequencing, and the intestinal metabolomics analysis of rats was performed by LC-MS methods. The 16 S rDNA sequencing revealed that the gut microbiome composition was significantly perturbed in children in DFG compared to that in CG. Acidobacteria and Thermi were specifically observed in DFG and CG, respectively. Besides, 15 fecal microbiotas were significantly altered at the genus level in DFG. Furthermore, only the expression of annotated genes for pentose and glucuronate interconversion pathway was significant lower in DFG than that in CG (P = 0.04). Notably, in NaF-treated rats, we also observed the changes of some key components of pentose and glucuronate interconversion pathway at the level of microorganisms and metabolites. Our findings suggested that the occurrence of DF is closely related to the alteration of intestinal microorganisms and metabolites annotated in the pentose and glucuronate interconversion pathway.

Changing the reaction pathway in TiO2 photocatalytic dehalogenation of halogenated aromatic pollutants by surface hydroxyl regulation

Understanding the photocatalytic reductive dehalogenation mechanism of halogenated aromatic pollutants is of great research value. However, the proton source in the photocatalytic dehalogenation process of representative halogenated aromatic pollutants by TiO₂ is not clear. In this study, the TiO₂ surface was modified by hydrochloric acid, sodium hydroxide, and sodium fluoride to obtain TiO₂ samples with different hydroxyl groups. It was found that the hydroxyl groups on the surface of TiO₂ affects the sequence of proton and electron transfer in dehalogenation. The abundance of hydroxyl groups on the surface of TiO₂ can accelerate the reductive dehalogenation process of representative halogenated aromatic pollutants. The kinetic solvent isotope effect was used to study the proton-coupled electron transfer process in the reaction. It shows that the enriching of protons on TiO₂ bridging oxygen (bridging hydroxyl groups) is conducive to the rapid step of protonation of the reactant, and subsequent proton and electron transfer. On the contrary, the bridging hydroxyl groups can be removed by reacting with strongly basic sodium hydroxide and sodium ions can occupy the bridging oxygen. The substitution of bridging oxygen by fluorine ions can also lead to the destruction of bridge hydroxyl groups. Significantly, the absence of bridging hydroxyl groups on titanium dioxide will lead to the dehalogenation of representative halogenated aromatic pollutants initiated by electron transfer. This study is helpful to understand dehalogenation reaction paths catalyzed by TiO₂.

Cross-talk between autophagy and ferroptosis contributes to the liver injury induced by fluoride via the mtROS-dependent pathway

Fluoride can induce hepatotoxicity, but the mechanisms responsible are yet to be investigated. This study sought to investigate the role and mechanism of mitochondrial reactive oxygen species (mtROS), autophagy, and ferroptosis in fluoride-induced hepatic injury with a focus on the role of mtROS-mediated cross-talk between autophagy and ferroptosis. To this end, an in vivo Sprague-Dawley rat model and in vitro BRL3A cells were exposed to sodium fluoride (NaF). The results revealed that NaF exposure diminished the mitochondrial membrane potential, increased mtROS production and TOMM20 expression, and induced autophagic flux blockage and ferroptosis in vivo and in vitro. Furthermore, the autophagy activator (RAPA) enhanced GPX4 expression while inhibiting ACSL4 expression, reduced the accumulation of ferrous ions in BRL3A cells, and restored lipid peroxidation levels, thus inhibiting ferroptosis. Fer-1, a ferritinase inhibitor, downregulated the expression of LC3-II and p62, increased the number of autolysosomes while decreasing the number of autophagosomes, and alleviated the blockage of autophagic flux by improving autophagic degradation. These results suggest the occurrence of a cross-talk between autophagy and ferroptosis. The mtROS inhibitor (Mito-TEMPO) could alleviate autophagic flux blockage and inhibit ferroptosis in NaF-induced liver injury. In addition, the cross-talk between NaF-induced autophagy and ferroptosis was dependent on the mtROS pathway.

"Vascular inflammation and cardiovascular disease: review about the role of PET imaging"

Inflammation characterizes all stages of atherothrombosis and provides a critical pathophysiological link between plaque formation and its acute rupture, leading to coronary occlusion and heart attack. In the last 20 years the possibility of quantifying the degree of inflammation of atherosclerotic plaques and, therefore, also of vascular inflammation aroused much interest. ¹⁸Fluoro-deoxy-glucose photon-emissions-tomography (¹⁸F-FDG-PET) is widely used in oncology for staging and searching metastases; in cardiology, the absorption of ¹⁸F-FDG into the arterial wall was observed for the first time incidentally in the aorta of patients undergoing PET imaging for cancer staging. PET/CT imaging with ¹⁸F-FDG and ¹⁸F-sodium fluoride (¹⁸F-NaF) has been shown to assess atherosclerotic disease in its molecular phase, when the process may still be reversible. This approach has several limitations in the clinical practice, due to lack of prospective data to justify their use routinely, but it's desirable to develop further scientific evidence to confirm this technique to detect high-risk patients for cardiovascular events.

Influence of long-term storage temperatures and sodium fluoride preservation on the stability of synthetic cathinones and dihydro-metabolites in human whole blood

PURPOSE

Synthetic cathinones, one of the largest groups of new psychoactive substances, represent a large analytical and interpretative challenge in forensic laboratories. Of these is the synthetic cathinones' instability in different biological samples, which may lead to drug concentration discrepancies when interpreting toxicological findings. In this study, the stability of a panel of synthetic cathinones and their dihydro-metabolites (n = 26) together with internal standard was monitored in human whole blood stored at various temperatures over 6 months. The influence of sodium fluoride as a preservative in blood collection tubes was also investigated.

METHODS

Samples were extracted using a two-step liquid-liquid extraction technique, and analyzed using a validated liquid chromatography-tandem mass spectrometry method following recommendations of published guidelines.

RESULTS

The influence of temperature over analytes' stability was an important element in whole blood samples, with - 40 °C being the best storage temperature for all tested analytes. Sodium fluoride did not significantly affect the stability of cathinones except at room temperature. Dihydro-metabolites displayed better stability in whole blood samples and remained detectable for a longer period of time under all tested conditions.

CONCLUSIONS

The data suggest that samples containing synthetic cathinones should be analyzed immediately, if possible. Alternatively, whole blood samples should be stored frozen (at - 40 °C or lower); however, (quantitative) results should be interpreted with caution after long-term storage. The data also promote the use of dihydro-metabolites as biomarkers for synthetic cathinones intake, as these reduced metabolites may be detected for longer period of time when compared with parent drugs in whole blood samples.

Efficacy of organic and antioxidant agents to regain bond strength to bleached enamel in different dental adhesive solvents

Materials like carbamide peroxide or hydrogen peroxide are commonly used for vital teeth bleaching. However, there have been concerns regarding their effect on composite-to-bleached enamel bonding strength. The study investigated the impact of organic and antioxidant agents on composite bond strength in bleached enamel with different dental adhesive solvents. Human third molar teeth were sectioned into buccal and lingual halves. The two main adhesive solvent groups evaluated were acetone and alcohol. Each main group was divided into six groups. The positive control group received no bleaching, the negative control group consisted of bleaching with no surface deoxidization; and other experimental categories involved post-bleach treatments with 95% ethanol, sodium ascorbate (10%), acetone solution, or sodium fluoride solution (1.1%). Following the surface treatment and enamel bonding procedure, nano-hybrid composite cylinders measuring 3 × 2 mm were directly cured over the bleached enamel substrate. The shear bond test was performed after 24-h storage and 12,000 thermocycles on a universal testing machine. In this study, one-way ANOVA was used along with Tukey's HSD tests at a significance level of 0.05. The negative control groups showed significantly lower bond strength than the positive control group. Ethanol surface treatment had superior mean bonding strength in acetone and alcohol-based adhesive solvent groups. The utilization of sodium ascorbate for surface treatment resulted in a significant enhancement of adhesion between the composite material and bleached enamel surface. Sodium fluoride application showed no significant recovery in shear bond strength in both dental adhesive groups. It was concluded that hydrogen peroxide severely compromised the immediate bond strength of composite resin. Surface treatment of bleached enamel with ethanol, sodium ascorbate, and acetone solutions is an effective option for restoring bond strength.

18F-sodium fluoride PET-CT visualizes both axial and peripheral new bone formation in psoriatic arthritis patients

PURPOSE

As bone formation is associated with psoriatic arthritis (PsA), positron emission tomography (PET) using a ¹⁸F-Fluoride tracer may enable sensitive detection of disease activity. Our primary aim was to determine the feasibility of whole-body ¹⁸F-sodium fluoride PET-CT in clinically active PsA patients to depict new bone formation (as a reflection of disease activity) at peripheral joints and entheses. Our secondary aim was to describe ¹⁸F-sodium fluoride findings in the axial skeleton.

METHODS

Sixteen patients (female 10/16, age 50.6 ± 8.9 years) with PsA fulfilling CASPAR criteria or with a clinical diagnosis of PsA according to the treating rheumatologist and with ≥ 1 clinically active enthesitis site were included. Of each patient, a whole-body ¹⁸F-sodium fluoride PET-CT scan was performed. All scans were scored for PET-positive lesions at peripheral joints, enthesis sites and the spine. Clinical disease activity was assessed by swollen/tender joint count 44, enthesitis according to MASES and SPARCC scores.

RESULTS

Out of 1088 evaluated joints, 109 joints showed PET enhancement, mainly in the interphalangeal and metatarsal joints of the feet (14/109, 12.9%) and the distal interphalangeal joints of the hands (14/109, 12.9%). PET positivity was found at 44/464 enthesis sites, mainly at the patella tendon insertion (11/44, 25%) and quadriceps tendon insertion (10/44, 22.7%). Of the PET-positive joints and enthesis sites, respectively 18.2% and 29.5% were clinically positive; 81.8% and 70.5% of the PET-positive joints and entheses respectively were clinically asymptomatic. In 11 patients, ≥ 1 axial PET-positive lesion was observed, mainly in the cervical spine.

CONCLUSIONS

New molecular bone formation was observed on ¹⁸F-sodium fluoride PET-CT scans, in all domains in which PsA disease activity can be observed, with a substantial part showing no clinical symptoms.

CLINICAL TRIAL REGISTRATION

EudraCT: 2017-004,850-40, registered on 13 December 2017.

HIF-1α-mediated autophagy and canonical Wnt/β-catenin signalling activation are involved in fluoride-induced osteosclerosis in rats

Fluoride (F) exposure can cause osteosclerosis, which is characterised by a high bone mass, but its mechanism is not fully illustrated. Here, we aimed to evaluate the effects of excessive F exposure on the bone lesion by treating female Sprague-Dawley rats with different concentrations of sodium fluoride (NaF) (0, 55, 110 and 221 mg/L) for 90 days and the corresponding concentrations of fluorine ion (0, 25, 50 and 100 mg/L, respectively). Histopathological results showed that excessive F exposure caused the enlargement of trabeculae and their integration into one large piece, growth plate thickening, articular cartilage impairment and bone collagen abnormality. Meanwhile, F promoted calcium deposition and bone mineralisation, and induced abnormal osteogenesis increased. The results of micro-computed tomography also confirmed that excessive F destroyed the bone microstructure and induced a high-bone-mass phenotype, consistent with the results of pathomorphology. Mechanistically, excessive amounts of F led to angiogenesis inhibition and HIF-1α signalling enhancement. Subsequently, F induced autophagy and canonical Wnt/β-catenin signalling pathway activation. Collectively, these results manifested that F enhanced the hypoxia inducible factor-1α signalling, which in turn triggered autophagy and canonical Wnt/β-catenin signalling activation, ultimately leading to osteosclerosis in the rats.

Bone metastases in prostate cancer - Gallium-68-labeled prostate-specific membrane antigen or Fluorine 18 sodium fluoride PET/computed tomography - the better tracer?

OBJECTIVE

The objective was to assess the roles of 68Ga-PSMA PET/CT and 18F-NaF PET/CT in evaluation of skeletal metastatic lesions in prostate cancer.

METHODS

Two hundred consecutive prostate cancer patients who had undergone 68Ga-PSMA PET/CT and 18F-NaF PET/CT at baseline evaluation (n = 80) and following suspected recurrence or disease progression (restaging) (n = 120) were analyzed retrospectively.

RESULTS

PSMA and NAF scans were positive for skeletal metastatic lesions in 67% (134 patients) and negative in 33% (66 patients). The scans were concordant in 80% (160 patients: 66 negative and 94 positive) and discordant in 20% (40 patients). Among 40 discordant results, 14 were baseline and 26 were restaging studies. PSMA detected more number of lesions in 11 (nine baseline and two restaging). These were true positive marrow or lytic metastatic lesions. NaF revealed more number of lesions in 29 (5 initial and 24 restaging). These were false positive on follow-up imaging. No statistical difference (P value = 0.7 by McNemar test) between the two scans for identifying absence or presence of at least one skeletal lesion was noted at baseline staging.

CONCLUSION

Though, both 18F-NaF and 68Ga-PSMA are excellent tracers for evaluation of skeletal metastases in prostate cancer, there is a distinct advantage of 68Ga-PSMA PET/CT due to detection of additional skeletal lesions and absence of false positive lesions. In addition, absence of PSMA avidity in healed metastases in the restaging setting opens up new avenue for assessment of response of skeletal metastases.

Associations between coronary/aortic 18F-sodium fluoride uptake and pro-atherosclerosis factors in patients with multivessel coronary artery disease

BACKGROUND

18F-NaF PET/CT is a novel approach to detect and quantify microcalcification in atherosclerosis. We aimed to explore the underlying systematic vascular osteogenesis in the coronary artery and aorta in patients with multivessel coronary artery disease (CAD).

METHODS

Patients with multivessel CAD prospectively underwent 18F-NaF PET/CT. The coronary microcalcification activity (CMA) and aortic microcalcification activity (AMA) were calculated based on both the volume and intensity of 18F-NaF PET activity. Peri-coronary adipose tissue (PCAT) density was measured in adipose tissue surrounding the coronary arteries and the 18F-NaF tissue-to-blood ratio (TBR) was measured in the coronary arteries.

RESULTS

100 patients with multivessel CAD were prospectively recruited. The CMA was significantly associated with the AMA (r = 0.70; P < .001). After multivariable adjustment, the CMA was associated with the AMA (Beta = 0.445 per SD increase; P < .001). The coronary TBR was also significantly associated with the PCAT density (r = 0.56; P < .001). The PCAT density was independently associated with the coronary TBR after adjusting confounding factors.

CONCLUSIONS

Coronary 18F-NaF uptake was significantly associated with the PCAT density. There was a significant relationship between the coronary and the aortic 18F-NaF uptake. It might indicate an underlying systematic vascular osteogenesis in patients with multivessel CAD.