Density Measurements Research Articles

Exploring bone density analysis on routine CT scans as a tool for opportunistic osteoporosis screening

The primary aim of this study was to evaluate computed tomography (CT)-based bone density analysis at the level of thoracic vertebra 12 (Th12) as a screening method for decreased bone density in patients admitted to the intensive care unit (ICU). Interobserver variability was analyzed. Secondary aims were to assess the prevalence of CT-based low bone density upon ICU admission in a cohort of COVID-19 patients and to assess the potential effect of long-term ICU stay on bone density in these patients. Retrospective single-center cohort study. ICU of the Leiden University Medical Center (LUMC), the Netherlands. Patients admitted to the ICU of the LUMC between March 1st, 2020 and February 1st, 2022 with a diagnosis of COVID-19, and a length of ICU stay of ≥ 21 days. In the included patients both baseline chest CT scans (obtained upon ICU admission) and follow-up chest CT scans (obtained ≥ 21 days after ICU admission) were available for analysis. A total of 118 CT scans in 38 patients were analyzed. There was a good interobserver variability, with an overall mean absolute difference (between measurements of three observers) of 9.7 Hounsfield Units (HU) and an intraclass correlation coefficient (ICC) of 0.93 (95% CI 0.88–0.96). The effect of intravenous contrast administration on bone density measurements was small (+ 7.5 HU (95% CI 3.4–11.5 HU)) higher in contrast enhanced CT images compared to non contrast enhanced CT images). Thirty-seven percent of patients had a bone density < 140 HU, suggestive of osteoporosis. No significant difference was found between bone density upon ICU admission and bone density at follow-up (≥ 21 days after ICU admission). Vertebral CT-based bone density analysis using routine CT scans is an easily applicable method to identify ICU patients with decreased bone density, which could enable enrollment in osteoporosis prevention programs. A high prevalence of low bone density was found in our cohort of ICU patients. There were no changes observed in bone density between baseline and follow-up measurements.

Effect of Dislocation Density on the Dynamic Strength of Aluminium

AbstractThe effects of cold work on dynamic flow strength is studied through measurements of dislocation density and elastic precursor attenuation in shocked aluminium. High-purity aluminium and Al 6082 alloy samples are subjected to up to three passes of rotary swaging, a severe plastic deformation (SPD) technique, in order to produce large variations in starting material conditions. Detailed material characterisation is performed using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) to determine the initial dislocation density, texture, grain boundary density and misorientation distribution. Variations in dynamic strength are studied through the evolution of the elastic precursor amplitude with propagation distance in specimens with thicknesses between 0.2 and 1 mm, shock loaded to impact stresses of about 4.6 GPa. It is shown that dynamic strength decreases with increasing initial dislocation density in both materials, demonstrating rare, quantified measurements of a reversal in the effect of dislocation density on yield strength at strain rates around 10$$^{4}$$ 4 s$$^{-1}$$ - 1 and above.

Comparing geophysical inversion and petrophysical measurements for northern Victoria Land, Antarctica

Summary Bedrock geology from Antarctica remains largely unknown since it is hidden beneath thick ice sheets. Geophysical methods such as gravity and magnetic inverse modelling provide a framework to infer crustal rock properties indirectly in Antarctica. However, due to limited availability of rock samples, validation against direct geological information is challenging. We present a new rock property catalogue containing density and susceptibility measurements on 320 rock samples from northern Victoria Land. This catalogue is used to assess the reliability of local and regional scale inverse results, including a new local high resolution magnetic inversion in the Mesa Range region and a previously published regional scale joint inversion of gravity and magnetic data in northern Victoria Land and the Wilkes Subglacial Basin. We compare our density and susceptibility measurements to global and local measurements from the literature to access the correlation to rock types and geological units. Furthermore, the measured values are compared against inverted values. The close correspondence between inverted and measured rock properties allows us to predict locations of rock types where currently such information is missing. The utility of measured susceptibility and density relationships for interpreting inversion output provides a strong incentive to incorporate local rock samples into geophysical studies of subglacial geology across Antarctica.

Measurement of the distal bile duct density on computed tomography can differentiate choledocholithiasis from a control population.

Hounsfield unit density of biliary fluid on CT may be a useful clinical marker that has not been described in the literature. This method has been used to differentiate pyonephrosis from hydronephrosis in obstructed collecting systems of the kidney. We aimed to create a user-friendly technique to measure the density of the distal bile duct using CT. The bile duct density of cases with proven choledocholithiasis at ERCP were compared with those of a control group (no biliary pathology). A total of 106 patients with proven choledocholithiasis at ERCP and 50 control patients were analysed. The distal bile duct density was calculated using the 4-point and max ellipse methods. Two blinded, independent investigators calculated the bile duct density. The HU is significantly higher in the presence of choledocholithiasis (P < 0.0001). Using the Youden index a cut-off value of 28.6 HU for the 4-point technique is useful to predict the presence of choledocholithiasis (Sensitivity 58%, Specificity 86%). Calculation of the distal bile duct density can differentiate choledocholithiasis from a control population. It may be useful alone or as a component of a scoring system to select patients more effectively for intervention. The improved use of CT may also decrease use of MRCP and reduce time to ERCP, which have potential cost benefits.

Effect of gold nanoparticle dispersion on the structural, optical and radiation shielding parameters of sodium Borate glass

Abstract Borate-derived radiation shielding glasses have been thoroughly explored, yet the effects of gold nanoparticle (GNP) dispersion on sodium borate glasses remain unstudied. This study investigates the impact of GNP dispersion and varying GNP concentrations on the radiation shielding properties and other parameters of sodium borate glass. All the glasses were prepared using the melt-quench technique with a composition of 30Na₂O-70B₂O₃, containing 0, 3 × 10⁸, and 3 × 10⁹ nanoparticles. The X-ray diffractogram confirmed the amorphous nature of the prepared glass samples, while Fourier Transform Infrared Spectroscopy (FTIR) confirmed structural modifications, indicated by the formation of non-bridging oxygens due to the incorporation of GNPs. High-resolution transmission electron microscopy (HR-TEM) confirmed the presence of GNPs with an average size of 1.317 nm, and Field Emission Scanning Electron Microscopy (FESEM) revealed further coagulation of GNPs into tiny grains to alleviate surface stresses. Density measurements showed a clear decrease from 2.3051 to 2.1363 g/cm³ with the incorporation of gold nanoparticles. Additionally, a localized surface plasmon resonance peak centered at 612 nm was observed in the UV‒Vis spectrogram of the glass with the highest GNP concentration. Radiation shielding parameters, including the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), and effective atomic number (Zeff), were analyzed using Phy-X/PSD software. The LAC value initially decreases from 78.046 to 72.330 cm⁻¹ with the incorporation of GNPs but increases to 77.846 cm⁻¹ with a higher GNP concentration. This glass system exhibited superior radiation shielding parameters compared to various reported glass systems, indicating its potential for shielding applications.

Correlation Among Neighborhood-level Measures of the Tobacco Retail Environment.

Tobacco retailer density and distance to tobacco retailers are understood to influence tobacco-related behaviors; however, there is no general agreement on how to best characterize or measure the tobacco retail environment (TRE). In this data-driven analysis, we examine similarities among neighborhood-level measures of the TRE and assess how geographic resolution of the neighborhood units may affect them. We used locations of likely tobacco retailers in the United States (US) to calculate multiple retailer count, density, and distance measures. Measures were calculated at the Census block group, tract, and county (including county equivalents) levels of geographic aggregation. Spearman's correlation was used to evaluate similarity among the TRE measures. At the block group and tract level, correlation among all TRE measures ranged from slightly negative (ρ = -0.03) to nearly perfect (ρ = 0.99). At both levels of aggregation, distance-based TRE measures were highly correlated (ρ > 0.76). At the block group level, simple count of retailers was highly correlated with the density measures (ρ > 0.83), and at the tract level, simple count was moderately to highly correlated with the density measures (ρ > 0.5). Findings were generally similar at the county level; a notable deviation was that retailers per person was negatively correlated with all other TRE measures (range from ρ = -0.08 to ρ = -0.32). Some common measures were not correlated, suggesting they capture different aspects of the TRE; similarity among the various measures also varied by level of geographic aggregation. Because the tobacco retail environment shapes people's tobacco-related behaviors, using appropriate measures to characterize it at a neighborhood-level is paramount. Our work highlights both the similarities and differences among a set of common measures, thereby suggesting the measures may be capturing different aspects of the overall retail environment. Our findings regarding geographic level of aggregation underscore the importance of neighborhood definition in any tobacco retail environment analysis.

Iodine Density Threshold to Distinguish Between Enhancing and Nonenhancing Renal Lesions With Dual-Layer Dual-Energy CT.

This study aimed to determine the optimal threshold iodine density to distinguish enhancing and nonenhancing renal masses with dual-layer dual-energy CT (dlDECT). In this retrospective, HIPAA-compliant, institutional review board-approved study, 383 consecutive renal mass dlDECT studies from September 5, 2018, through December 15, 2022, were reviewed for enhancing solid renal masses with ≥∆20 HU. Studies with simple cysts in the same interval served as controls. Lesion ROI HU measurements on unenhanced and nephrographic phases and ROI iodine density measurements of each lesion and the abdominal aorta for normalization were recorded. The mean lesion HU values and absolute and normalized iodine densities were compared with enhancing and nonenhancing renal lesions using a two-sample t test. The diagnostic accuracy of iodine thresholds was assessed by calculating sensitivity and specificity, with receiver operating characteristic curve and AUC analysis. There were 38 enhancing and 39 nonenhancing renal lesions. The mean (standard deviation [SD]) ∆HU was 73.5 (38.7) and 3.9 (5.1) HU for enhancing and nonenhancing lesions, respectively. The mean absolute iodine density was significantly different for enhancing and nonenhancing lesions (3.2 [1.7] mg/mL and 0.20 [0.22] mg/mL, respectively; P < 0.0001). Normalized mean iodine density was significantly different for enhancing and nonenhancing lesions (0.62 [0.33] mg/mL and 0.04 [0.04] mg/mL, respectively; P < 0.0001). The optimal absolute iodine density threshold of 0.70 mg/mL (AUC, 0.999) and normalized iodine density threshold of 0.11 mg/mL (AUC, 0.999) were 100% sensitive and 97.4% specific for discriminating enhancing and nonenhancing renal lesions. This study provides absolute and normalized iodine density thresholds to distinguish enhancing and nonenhancing renal lesions with high sensitivity and specificity using dlDECT.

Reproducibility of CT-based opportunistic vertebral volumetric bone mineral density measurements from an automated segmentation framework

BackgroundTo investigate the reproducibility of automated volumetric bone mineral density (vBMD) measurements from routine thoracoabdominal computed tomography (CT) assessed with segmentations by a convolutional neural network and automated correction of contrast phases, on diverse scanners, with scanner-specific asynchronous or scanner-agnostic calibrations.MethodsWe obtained 679 observations from 278 CT scans in 121 patients (77 males, 63.6%) studied from 04/2019 to 06/2020. Observations consisted of two vBMD measurements from Δdifferent reconstruction kernels (n = 169), Δcontrast phases (n = 133), scan Δsessions (n = 123), Δscanners (n = 63), or Δall of the aforementioned (n = 20), and observations lacking scanner-specific calibration (n = 171). Precision was assessed using root-mean-square error (RMSE) and root-mean-square coefficient of variation (RMSCV). Cross-measurement agreement was assessed using Bland-Altman plots; outliers within 95% confidence interval of the limits of agreement were reviewed.ResultsRepeated measurements from Δdifferent reconstruction kernels were highly precise (RMSE 3.0 mg/cm3; RMSCV 1.3%), even for consecutive scans with different Δcontrast phases (RMSCV 2.9%). Measurements from different Δscan sessions or Δscanners showed decreased precision (RMSCV 4.7% and 4.9%, respectively). Plot-review identified 12 outliers from different scan Δsessions, with signs of hydropic decompensation. Observations with Δall differences showed decreased precision compared to those lacking scanner-specific calibration (RMSCV 5.9 and 3.7, respectively).ConclusionAutomatic vBMD assessment from routine CT is precise across varying setups, when calibrated appropriately. Low precision was found in patients with signs of new or worsening hydropic decompensation, what should be considered an exclusion criterion for both opportunistic and dedicated quantitative CT.Relevance statementAutomated CT-based vBMD measurements are precise in various scenarios, including cross-session and cross-scanner settings, and may therefore facilitate opportunistic screening for osteoporosis and surveillance of BMD in patients undergoing routine clinical CT scans.Key PointsArtificial intelligence-based tools facilitate BMD measurements in routine clinical CT datasets.Automated BMD measurements are highly reproducible in various settings.Reliable, automated opportunistic osteoporosis diagnostics allow for large-scale application.Graphical

Effectiveness of bone plate reduction combined with resorbable plate fixation in the treatment of large mandibular cysts.

This study aims to observe the clinical effect of bone plate reduction in combination with a resorbable plate on large mandibular cysts. Between October 2017 and September 2022, patients with large mandibular cysts in the presence of labial and buccal cortical bone were involved in the study. Intraoral approach was performed for bone plate reduction. Cone beam computed tomography (CBCT) scan was reviewed at 3, 6, and 9 months postoperatively to observe postoperative complications. Osteogenic results were assessed at these times to determine the clinical outcomes of this procedure. Eleven cases with large mandibular cysts in the presence of cortical bone were evaluated. The average thickness of the cortical bone on the labial and buccal sides was measured to be about (1.98±0.37) mm before surgery, with a mean value of (0.73±0.17) mm at the thinnest part of the plate and up to 0.51 mm at the thinnest part of the plate. The cystic cavities were well revealed during the surgeries, which were completed successfully. Postoperatively, the wounds healed in one stage without infection. The percentages of cyst shrinkage were 20.01%, 41.76%, and 73.41% at 3, 6, and 9 months after surgery, respectively. Quantitative measurement of bone mineral density in the jaws by CBCT with MIMICS software. The bone mineral densities of the adult bone were 313.78, 555.85, and 657.45 HU at the 3, 6, and 9 month time intervals, respectively. No significant change in the patient's maxillofacial appearance were observed from the preoperative period as assessed by the patient's and observer's visual analog scale. Bone plate reduction is an effective treatment for large mandibular cysts of the oral and maxillofacial region with the presence of cortical bone.

Correlation study: Bone density and circulating inflammatory markers in postmenopausal patients.

This study aims to investigate the correlation between changes in bone mineral density (BMD) in postmenopausal women and circulating inflammatory markers. This retrospective study focused on postmenopausal women admitted to the orthopedic department of Suzhou Benq Medical Center from June 2022 to December 2023, following predetermined inclusion and exclusion criteria. We retrospectively collected data on initial blood routine test results and bone density measurements for all study subjects upon admission, including parameters such as white blood cell count (WBC), C-reactive protein, interleukin-6 (IL-6), and procalcitonin (PCT). Additionally, the systemic immune-inflammation index (SII) was calculated using neutrophil count, lymphocyte count, and platelet count. Statistical analyses using SPSS and GraphPad software were performed to assess the correlation between bone density and inflammatory markers. Patients were classified into three groups based on BMD results, including 60 individuals in the osteoporosis (OP) group, 127 individuals in the osteopenia group, and 37 individuals in the Normalgroup, respectively. Principal component analysis analysis suggested that WBC, SII, and postmenopausal OP(PMOP) held significant feature values. Correlation analysis indicated a correlation between WBC (p = 0.021), IL-6 (p = 0.044), SII (p = 0.034), and PMOP. One-way ANOVA analysis revealed significant differences in IL-6 (p = 0.0179), SII (p = 0.0210), and PCT (p = 0.0200) among the three groups. Finally, ROC curve analysis demonstrated that SII (area under the curve = 0.716) has predictive value for PMOP. This study identified a certain predictive value for PMOP through the assessment of inflammatory markers in peripheral blood using routine blood tests.

The relationship between bone health and type of intracranial internal carotid calcifications in patients with ischemic stroke

IntroductionVascular calcifications, primarily in the aorta and its proximal branches, are commonly observed among subjects with impaired bone health. In this study, we sought to determine if a comparable association holds true for the calcifications in the intracranial internal carotid arteries (IICA), in general and also for particular calcification patterns. MethodsA consecutive series of ischemic stroke patients were prospectively enrolled into the study, where computed tomography angiography source images were used to determine the presence and type of IICA calcifications, and dual-energy X-ray absorptiometry was used to determine the bone mineral density in the left femoral neck region. IICA calcifications were categorized as none, intimal, medial, and mixed types based on previously validated classification schemes. Their relationships with femoral bone T-scores were evaluated by bivariate and multivariate analyses. ResultsFemoral neck T-score was highest among patients without any vascular calcifications (n=65), when compared to the bone density measures among patients with any type of calcification (n=185) (p<0.001). After adjustment for age, gender, vascular risk factors, and serum biomarkers related to bone health, the T-score remained significantly associated only with the pattern of intimal calcification [OR 0.63 (0.42 – 0.95), p=0.028]. ConclusionsOur findings suggest that the intracranial vasculature, in particular the internal carotid arteries, is not immune to the interplay between suboptimal bone health and vascular calcifications. This association was most robust for an intimal type of IICA calcification pattern, while no such relationship could be demonstrated for other types of vascular calcifications.

Methodological constrains of tree-ring stable isotope chronologies

Tree-ring stable isotope (TRSI) chronologies that combine information from living and relict wood have the potential to capture long-term trends that might be missing in traditional tree-ring width and maximum latewood density measurements. Our understanding of the possible effects of different methods to develop TRSI chronologies is, however, still incomplete. Here, we compare and evaluate five such methods applied to three multi-millennial-long oxygen isotope (δ18O) TRSI datasets from central Europe, the European Alps and Japan: (a) raw data, (b) cohort correction, (c) interactive mean correction, (d) outlier correction, and (e) series normalization. We show that the spectral properties preserved in the final TRSI chronologies not only depend on the data used, but also on the techniques applied. Method (a) is particularly prone to outliers if the sample size is low. Method (b) may create artificial steps and trends when single measurement series share similar start dates and/or when end and start dates are systematically skewed. Methods (c) and (d) yield similar results for annually resolved data, yet (d) is more suitable for temporally pooled datasets and less sensitive to potential biological age effects. Method (e) removes any low-frequency signal. Our findings demonstrate the risks and rewards of different TRSI chronology development techniques that must be carefully adapted to both, the data used and the question posed.

Multifaceted density dependence: Social structure and seasonality effects on Serengeti lion demography.

Interactions between density and environmental conditions have important effects on vital rates and consequently on population dynamics and can take complex pathways in species whose demography is strongly influenced by social context, such as the African lion, Panthera leo. In populations of such species, the response of vital rates to density can vary depending on the social structure (e.g. effects of group size or composition). However, studies assessing density dependence in populations of lions and other social species have seldom considered the effects of multiple socially explicit measures of density, and-more particularly for lions-of nomadic males. Additionally, vital-rate responses to interactions between the environment and various measures of density remain largely uninvestigated. To fill these knowledge gaps, we aimed to understand how a socially and spatially explicit consideration of density (i.e. at the local scale) and its interaction with environmental seasonality affect vital rates of lions in the Serengeti National Park, Tanzania. We used a Bayesian multistate capture-recapture model and Bayesian generalized linear mixed models to estimate lion stage-specific survival and between-stage transition rates, as well as reproduction probability and recruitment, while testing for season-specific effects of density measures at the group and home-range levels. We found evidence for several such effects. For example, resident-male survival increased more strongly with coalition size in the dry season compared with the wet season, and adult-female abundance affected subadult survival negatively in the wet season, but positively in the dry season. Additionally, while our models showed no effect of nomadic males on adult-female survival, they revealed strong effects of nomads on key processes such as reproduction and takeover dynamics. Therefore, our results highlight the importance of accounting for seasonality and social context when assessing the effects of density on vital rates of Serengeti lions and of social species more generally.

Association between Trace elements and cognitive function among Elderly Subjects with Osteoporosis: A retrospective study

Background: Cognitive dysfunction and osteoporosis (OP) are common among elderly subjects. Different mechanisms are reported. However the potential role of trace elements is not well studied. The current work aimed to estimate the toenail levels of trace elements in older patients with cognitive function with or without osteoporosis. Methods: In a retrospective manner, we collected data of people older than 60 years of age. We collected data of 165 subjects, with 1:1:1 distribution for studied groups (i.e., 55 subjects in each group). The first group for normal cognition with no OP; the second for cognitive dysfunction with no OP and the third for cognitive dysfunction with OP. The cognitive function was determined by the mini-mental state examination (MMSE), while osteoporosis was diagnosed by the measurement of bone mineral density (BMD) with calculation of T-scores. Toenail samples were collected and prepared to estimate the levels of trace elements. Results: Calcium and zinc were significantly reduced in groups (2 and 3) than the normal group (15.44±1.17 and 13.47±1.81 versus 18.93±1.90 µg/g, respectively; and 88.16±6.10 and 84.07±6.56 versus 104.27±4.79 µg/g, respectively). However, there were significant increase of toenail lead, aluminum and copper in the second and third groups than the first group. But, chromium and selenium were reduced in the second and third groups than the first group. The MMSE and T-scores were proportionately correlated with T-score, body mass index, calcium, zinc, chromium and selenium. But, inversely correlated with lead, aluminum and copper. Finally, calcium, zinc lead, age and BMI were the significant predictors of cognitive impairment and OP. Conclusion: Trace elements are associated with cognitive impairment with or without osteoporosis. Some are protective and others had harmful effects with different mechanism. Thus, monitoring of these trace elements should be considered to avoid further cognitive decline with or without osteoporosis in future.

Electron density measurement of Ar, N2, O2, and Ar mixtures (with N2 and O2) gas in inductively coupled plasma (ICP) using terahertz time domain spectroscopy

In this study, an inspection method using terahertz waves was proposed for the diagnosis of electron density using inductively coupled plasma (ICP). Plasma with low and high electron density for Ar, N2, O2, and Ar mixed (with N2 and O2) gases was generated by varying the RF power of the ICP and mass flow rate. Based on the theoretical analysis about propagation characteristics of the THz waves in Ar, N2, O2, and Ar mixed (with N2 and O2) gas plasma, the electron density of the ICP was measured according to RF power and mass flow rate. These results were verified using a Langmuir probe that can measure the electron density distribution.

Copper Iodide Hybrid with Unique Cu3I3 Trimeric Inorganic Functional Unit and Far‐red/Near‐infrared Emission

AbstractIn this paper, a neutral copper iodide hybrid with unique Cu3I3 trimeric inorganic functional unit is successfully fabricated using 5,6,7,8‐tetrahydroquinoxaline (L) with large steric‐hindrance group as the organic ligand. The hybrid owns a one‐dimensional (1D) extended polymeric structure in the form of Cu3I3(L)2. As a CuI‐based hybrid, 1D‐Cu3I3(L)2 has an infrequent far‐red/near‐infrared emission, exhibiting the potential application prospects in the field of display and night vision. Moreover, the luminescence mechanism is carefully studied by decay lifetime measurement and calculation of density of states, which is verified to be the combination of metal‐to‐ligand charge transfer and halide‐to‐ligand charge transfer.

Goal-Directed Osteoporosis Treatment: ASBMR/BHOF Task Force Position Statement 2024.

The overarching goal of osteoporosis management is to prevent fractures. A goal-directed approach to long-term management of fracture risk helps ensure that the most appropriate initial treatment and treatment sequence is selected for individual patients. Goal-directed treatment decisions require assessment of clinical fracture history, vertebral fracture identification (using vertebral imaging as appropriate), measurement of bone mineral density (BMD) and consideration of other major clinical risk factors. Treatment targets should be tailored to each patient's individual risk profile and based on the specific indication for beginning treatment, including recency, site, number and severity of prior fractures, and BMD levels at the total hip, femoral neck, and lumbar spine. Instead of first-line bisphosphonate treatment for all patients, selection of initial treatment should focus on reducing fracture risk rapidly for patients at very high and imminent risk, such as in those with recent fractures. Initial treatment selection should also consider the probability that a BMD treatment target can be attained within a reasonable period of time and the differential magnitude of fracture risk reduction and BMD impact with osteoanabolic versus antiresorptive therapy. This position statement of the ASBMR/BHOF Task Force on Goal-Directed Osteoporosis Treatment provides an overall summary of the major clinical recommendations about treatment targets and strategies to achieve those targets based on the best evidence available, derived primarily from studies in older postmenopausal women of European ancestry.

Idiopathic juvenile osteoporosis - a polygenic disorder?

Abstract Idiopathic juvenile osteoporosis (IJO) is a rare condition presenting with vertebral and metaphyseal fractures that affects otherwise healthy prepubertal children. Bone mineral density (BMD) measurements are very low. The primary problem appears to be deficient bone formation, with a failure to accrue bone normally during growth. The onset in childhood suggests IJO is a genetic disorder, and a number of reports indicate that some children carry heterozygous pathogenic variants in genes known to be associated with defective osteoblast function and low bone mass, most commonly LRP5 or PLS3. However, a positive family history is unusual in IJO, suggesting the genetic background can be complex. We describe a young man with classical IJO who was investigated with a bone fragility gene panel and whole genome sequencing. The proband was found to carry four variants in three different genes potentially affecting osteoblast function. From his mother he had inherited mutations in ALPL (p.Asn417Ser) and LRP5 (p.Arg1036Gln), and from his father mutations in LRP5 (p.Asp1551Alsfs*13) and ATF4 (p.Leu306Ile). His sister had also inherited the LRP5 (p.Asp1551Alsfs*13) from her father, but not the ATF4 mutation. Their spinal BMD z-scores differed substantially (sister -1.6, father -3.2) pointing to the potential importance of the ATF4 mutation. Activating transcription factor 4 (ATF4) acts downstream from RUNX2 and osterix and plays an important role in osteoblast differentiation and function. This case, together with others recently published, support the view that IJO can result from clustering of mutations in genes related to osteoblast development and function. Novel genes in these pathways may be involved. Our case also emphasises the value of detailed study of other family members. After a bone biopsy had excluded a mineralization defect due to hypophosphatasia, the proband was treated with zoledronate infusions with good clinical effect.

Ambient PM2.5 components might exacerbate bone loss among middle-aged and elderly women: evidence from a population-based cross-sectional study.

Previous studies have primarily focused on the links between fine particulate matter (PM2.5) and bone health among the general population instead of PM2.5 components and the specific population. We aimed to investigate the associations between PM2.5 components and bone health among middle-aged and elderly women. A total of 748 middle-aged and elderly women were randomly sampled from 32 streets/villages in Hubei Province. The concentrations of ambient PM2.5 and its components were extracted across various residential areas from the Tracking Air Pollution in China (TAP) dataset. Bone mineral density measurements were obtained from dual-energy X-ray absorptiometry scans of study participants. Multivariable logistic and linear models were employed to assess the relationship between PM2.5 and its components and bone loss. Per interquartile range (IQR) increase in nitrate (NO3-) and ammonium (NH4+) concentrations were associated with 1.65 [95% confidence intervals (CI): 1.13, 2.30] and 1.77 (95% CI: 1.26, 2.49) times higher odds of osteoporosis, respectively. Long-term exposure to sulfate (SO42-), NO3-, and NH4+ was negatively associated with T-scores and bone mineral density in L1-L4 lumbar vertebrae. In addition, the elderly, women who have experienced menarche after the age of 14, and postmenopausal women were more susceptible to the water-soluble inorganic salts of PM2.5. The study emphasizes the need for comprehensive policies addressing air quality, with a specific focus on vulnerable populations such as middle-aged and elderly women. Public health interventions aimed at reducing ambient PM2.5 concentrations and minimizing exposure to its harmful components are crucial in mitigating the adverse impact on skeletal health and improving the overall well-being of communities.

Experimental measurements of the granular density of modes via impact

Experimental measurements of the granular density of modes via impact