Volume Fraction Of Tissue Research Articles

Lamina Cribrosa Microstructure in Nonhuman Primates With Naturally Occurring Peripapillary Retinal Nerve Fiber Layer Thinning.

The lamina cribrosa (LC) is hypothesized to be the site of initial axonal damage in glaucoma with the circumpapillary retinal nerve fiber layer thickness (RNFL-T) widely used as a standard metric for quantifying the glaucomatous damage. The purpose of this study was to determine in vivo, 3-dimensional (3D) differences in the microstructure of the LC in eyes of nonhuman primates (NHPs) with naturally occurring glaucoma. Spectral-domain optical coherence tomography (OCT) scans (Leica, Chicago, IL, USA) of the optic nerve head were acquired from a colony of 50 adult rhesus monkeys suspected of having high prevalence of glaucoma. The RNFL-T was analyzed globally and in quadrants using a semi-automated segmentation software. From a set of 100 eyes, 18 eyes with the thinnest global RNFL-T were selected as the study group and 18 eyes with RNFL-T values around the 50th percentile were used as controls. A previously described automated segmentation algorithm was used for LC microstructure analysis. Parameters included beam thickness, pore diameter and their ratio (beam-to-pore ratio [BPR]), pore area and shape parameters, beam and pore volume, and connective tissue volume fraction (CTVF; beam volume/total volume). The LC microstructure was analyzed globally and in the following volumetric sectors: quadrants, central and peripheral lamina, and three depth slabs (anterior, middle, and posterior). Although no significant difference was detected between groups for age, weight, or disc size, the study group had significantly thinner RNFL than the control group (P < 0.01). The study group had significantly smaller global and sectoral pore diameter and larger BPR compared with the control group. Across eyes, the global RNFL-T was associated positively with pore diameter globally. BPR and CTVF were significantly and negatively associated with the corresponding RNFL-T in the superior quadrant. Global and sectoral microstructural differences were detected when comparing thin and normal RNFL-T eyes. Whether these LC differences are the cause of RNFL damage or the result of remodeling of the LC requires further investigation. Our findings indicate structural alterations in the LC of NHP exhibiting natural thinning of the RNFL, a common characteristic of glaucomatous damage.

A photoresponsive recombinant human amelogenin-loaded hyaluronic acid hydrogel promotes bone regeneration.

In order to evaluate the effect of methacrylated hyaluronic acid (HAMA) hydrogels containing the recombinant human amelogenin (rhAm) invitro and invivo. The ultimate goal in treating periodontal disease is to control inflammation and achieve regeneration of periodontal tissues. In recent years, methacrylated hyaluronic acid (HAMA) containing recombinant human amyloid protein (rhAm) has been widely used as a new type of biomaterial in tissue engineering and regenerative medicine. However, there is a lack of comprehensive research on the periodontal regeneration effects of this hydrogel. This experiment aims to explore the application of photoresponsive recombinant human amelogenin-loaded hyaluronic acid hydrogel for periodontal tissue regeneration and provide valuable insights into its potential use in this field. The effects of rhAm-HAMA hydrogel on the proliferation of human periodontal ligament cells (hPDLCs) were assessed using the CCK-8 kit. The osteogenic differentiation of hPDLCs was evaluated through ALP staining and real-time PCR. Calvarial parietal defects were created in 4-week-old Sprague Dawley rats and implanted with deproteinized bovine bone matrix in different treatment groups. The animals were euthanized after 4 and 8 weeks of healing. The bone volume of the defect was observed by micro-CT and histological analysis. Stimulating hPDLCs with rhAm-HAMA hydrogel did not significantly affect their proliferation (p > .05). ALP staining and real-time PCR results demonstrated that the rhAm-HAMA group exhibited a significant upregulation of osteoclastic gene expression (p < .05). Micro-CT results revealed a significant increase in mineralized tissue volume fraction (MTV/TV%), trabecular bone number (Tb.N), and mineralized tissue density (MTD) of the bone defect area in the rhAm-HAMA group compared to the other groups (p < .05). The results of hematoxylin and eosin staining and Masson staining at 8 weeks post-surgery further supported the results of the micro-CT. The results of this study indicate that rhAm-HAMA hydrogel could effectively promote the osteogenic differentiation of hPDLCs and stabilize bone substitutes in the defects that enhance the bone regeneration invivo.

Photon-counting CT using multi-material decomposition algorithm enables fat quantification in the presence of iron deposits

PurposeA new generation of CT detectors were recently developed with the ability to measure individual photon’s energy and thus provide spectral information. The aim of this work was to assess the performance of simultaneous fat and iron quantification using a clinical photon-counting CT (PCCT) and its comparison to dual-energy CT (DECT), MRS and MRI at 3 T. MethodsTwo 3D printed cylindrical phantoms with 32 samples (n = 12 fat fractions between 0 % and 100 %, n = 20 with mixtures of fat and iron) were scanned with PCCT and DECT scanners for comparison. A three-material decomposition approach was used to estimate the volume fractions of fat (FF), iron and soft tissue. The same phantoms were examined by MRI (6-echo DIXON, a.k.a. Q-DIXON) and MRS (multi-echo STEAM, a.k.a. HISTO) at 3 T for comparison. ResultsPCCT, DECT, MRI and MRS computed FFs showed correlation with reference fat fraction values in samples with no iron (r > 0.98).PCCT decomposition showed slightly weaker correlation with FFref in samples with added iron (r = 0.586) compared to MRI (r = 0.673) and MRS (r = 0.716) methods. On the other hand, it showed no systematic over- or underestimation. Surprisingly, DECT decomposition-derived FF showed strongest correlation (r = 0.758) in these samples, however systematic overestimation was observed. FF values computed by three-material PCCT decomposition, DECT decomposition, MRI and MRS were unaffected by iron concentration. ConclusionsThis in-vitro study shows for the first time that photon-counting computed tomography may be used for quantification of fat content in the presence of iron deposits.

Lipid Storage, Lipolysis, and Lipotoxicity in Obesity.

The ratio of free fatty acid (FFA) turnover decreases significantly with the expansion of white adipose tissue. Adipose tissue and dietary saturated fatty acid levels significantly correlate with an increase in fat cell size and number. The G0/G1 switch gene 2 increases lipid content in adipocytes and promotes adipocyte hypertrophy through the restriction of triglyceride (triacylglycerol: TAG) turnover. Hypoxia in obese adipose tissue due to hypertrophic adipocytes results in excess deposition of extracellular matrix (ECM) components. Cluster of differentiation (CD) 44, as the main receptor of the extracellular matrix component regulates cell-cell and cell-matrix interactions including diet-induced insulin resistance. Excess TAGs, sterols, and sterol esters are surrounded by the phospholipid monolayer surface and form lipid droplets (LDs). Once LDs are formed, they grow up because of the excessive amount of intracellular FFA stored and reach a final size. The ratio of FFA turnover/lipolysis decreases significantly with increases in the degree of obesity. Dysfunctional adipose tissue is unable to expand further to store excess dietary lipids, increased fluxes of plasma FFAs lead to ectopic fatty acid deposition and lipotoxicity. Reduced neo-adipogenesis and dysfunctional lipid-overloaded adipocytes are hallmarks of hypertrophic obesity linked to insulin resistance. Obesity-associated adipocyte death exhibits feature of necrosis-like programmed cell death. Adipocyte death is a prerequisite for the transition from hypertrophic to hyperplastic obesity. Increased adipocyte number in obesity has life-long effects on white adipose tissue mass. The positive correlation between the adipose tissue volume and magnetic resonance imaging proton density fat fraction estimation is used for characterization of the obesity phenotype, as well as the risk stratification and selection of appropriate treatment strategies. In obese patients with type 2 diabetes, visceral adipocytes exposed to chronic/intermittent hyperglycemia develop a new microRNAs' (miRNAs') expression pattern. Visceral preadipocytes memorize the effect of hyperglycemia via changes in miRNAs' expression profile and contribute to the progression of diabetic phenotype. Nonsteroidal anti-inflammatory drugs, metformin, and statins can be beneficial in treating the local or systemic consequences of white adipose tissue inflammation. Rapamycin inhibits leptin-induced LD formation. Collectively, in this chapter, the concept of adipose tissue remodeling in response to adipocyte death or adipogenesis, and the complexity of LD interactions with the other cellular organelles are reviewed. Furthermore, clinical perspective of fat cell turnover in obesity is also debated.

Tracking Cerebral Microvascular and Metabolic Parameters during Cardiac Arrest and Cardiopulmonary Resuscitation

Hemodynamic models provide a mathematical representation and computational framework that describe the changes in blood flow, blood volume, and oxygenation levels that occur in response to neural activity and systemic changes, while near-infrared spectroscopy (NIRS) measures deoxyhemoglobin, oxyhemoglobin, and other chromophores to analyze cerebral hemodynamics and metabolism. In this study, we apply a dynamic hemometabolic model to NIRS data acquired during cardiac arrest and cardiopulmonary resuscitation (CPR) in pigs. Our goals were to test the model’s ability to accurately describe the observed phenomena, to gain an understanding of the intricate behavior of cerebral microvasculature, and to compare the obtained parameters with known values. By employing the inverse of the hemometabolic model, we measured a range of significant physiological parameters, such as the rate of oxygen diffusion from blood to tissue, the arteriole and venule volume fractions, and the Fåhraeus factor. Statistical analysis uncovered significant differences in the baseline and post-cardiac arrest values of some of the parameters.

The influence of static portal pressure on liver biophysical properties.

The liver is a highly vascularized organ where fluid properties, including vascular pressure, vessel integrity and fluid viscosity, play a critical role in gross mechanical properties. To study the effects of portal pressure, liver confinement, fluid viscosity, and tissue crosslinking on liver stiffness, water diffusion, and vessel size, we applied multiparametric magnetic resonance imaging (mpMRI), including multifrequency magnetic resonance elastography (MRE) and apparent diffusion coefficient (ADC) measurements, to ex vivo livers from healthy male rats (13.6±1.6 weeks) at room temperature. Four scenarios including altered liver confinement, tissue crosslinking, and vascular fluid viscosity were investigated with mpMRI at different portal pressure levels (0-17.5 cmH2O). Our experiments demonstrated that, with increasing portal pressure, rat livers showed higher water content, water diffusivity, and increased vessel sizes quantified by the vessel tissue volume fraction (VTVF). These effects were most pronounced in native, unconfined livers (VTVF: 300±120%, p<0.05, ADC: 88±29%, p<0.01), while still significant under confinement (confined: VTVF: 53±32%, p<0.01, ADC: 28±19%, p<0.05; confined-fixed: VTVF: 52±20%, p<0.001, ADC: 11±2%, p<0.01; confined-viscous: VTVF: 210±110%, p<0.01, ADC: 26±9%, p<0.001). Softening with elevated portal pressure (-12±5, p<0.05) occurred regardless of confinement and fixation. However, the liver stiffened when exposed to a more viscous inflow fluid (11±4%, p<0.001). Taken together, our results elucidate the complex relationship between macroscopic-biophysical parameters of liver tissue measured by mpMRI and vascular-fluid properties. Influenced by portal pressure, vascular permeability, and matrix crosslinking, liver stiffness is sensitive to intrinsic poroelastic properties, which, alongside vascular architecture and water diffusivity, may aid in the differential diagnosis of liver disease. STATEMENT OF SIGNIFICANCE: Using highly controllable ex vivo rat liver phantoms, hepatic biophysical properties such as tissue-vascular structure, stiffness, and water diffusivity were investigated using multiparametric MRI including multifrequency magnetic resonance elastography (MRE) and diffusion-weighted imaging (DWI). Through elaborate tuning of the experimental conditions such as the static portal pressure, flow viscosity, amount and distribution of fluid content in the liver, we identified the contributions of the fluid component to the overall imaging-based biophysical properties of the liver. Our finding demonstrated the sensitivity of liver stiffness to the hepatic poroelastic properties, which may aid in the differential diagnosis of liver diseases.

Correlation analysis of the abdominal visceral fat area with the structure and function of the heart and liver in obesity: a prospective magnetic resonance imaging study

BackgroundThe differences in fat deposition sites exhibit varying degrees of systemic inflammatory responses and organ damage, especially in obese individuals with excessive visceral fat. Visceral fat, which is closely related to an increase in mortality rates related to heart and liver diseases. However, few studies have analysed the differences in heart and liver indicators and their correlation among groups based on the abdominal visceral fat area (AVFA).ObjectiveClarifying the differences in and correlations of heart and liver indicators among groups with different severities of AVFA by magnetic resonance imaging (MRI).MethodsSixty-nine subjects with obesity were enrolled. The study group consisted of forty-one individuals (AVFA ≥ 150 cm2), and the control group consisted of twenty-eight individuals (100 cm2 ≤ AVFA < 150 cm2). The differences in and correlations between clinical, laboratory, and MRI indicators of the heart and liver between the two groups were analysed.ResultsIn the study group, the incidences of type 2 diabetes mellitus (T2DM) and insulin resistance were higher, and liver function indicators were worse. The left ventricular eccentricity ratio (LVER), left ventricular mass (LVM) and global peak wall thickness (GPWT) were higher in the study group than in the control group (P = 0.002, P = 0.001, P = 0.03), and the left ventricle global longitudinal strain (LVGLS) was lower in the study group than in the control group (P = 0.016). The pericardiac adipose tissue volume (PATV) and myocardial proton density fat fraction (M-PDFF) were higher in the study group than in the control group (P = 0.001, P = 0.001). The hepatic proton density fat fraction (H-PDFF) and abdominal subcutaneous fat area (ASFA) were higher in the study group than in the control group (P < 0.001, P = 0.012). There was a moderate positive correlation (ρ = 0.39–0.59, P < 0.001) between the AVFA and LVER, LVM, GPWT, LVGLS, and H-PDFF. There was no difference in right ventricular and most left ventricular systolic and diastolic function between the two groups.ConclusionThe high AVFA group had a larger LVM, GPWT and PATV, more obvious changes in LVER, impaired left ventricular diastolic function, an increased risk of heart disease, and more severe hepatic fat deposition and liver injury. Therefore, there is a correlation between the amount of visceral adipose tissue and subclinical cardiac changes and liver injury.

Graded levels of Eimeria challenge altered the microstructural architecture and reduced the cortical bone growth of femur of Hy-Line W-36 pullets at early stage of growth (0–6 wk of age)

An experiment was carried out to evaluate the impact of mixed Eimeria challenge on skeletal health of Hy-Line W-36 pullets. A total of 540, 16-day-old pullets were randomly allocated into 5 treatment groups, including a nonchallenged control. A mixed Eimeria species solution containing 50,000E. maxima, 50,000E. tenella, and 250,000E. acervulinaoocysts per mL was prepared and challenged to 1 group as a high-dose treatment. The 2-fold serial dilution was done to prepare the medium-high (25,000E. maxima; 25,000E. tenella; 125,000E. acervulina), the medium-low (12,500E. maxima; 12,500E. tenella; 62,500E. acervulina), and the low (6,250E. maxima; 6,250E. tenella; 31,250E. acervulina) dose treatments which were challenged to 3 corresponding groups, respectively. The mineral apposition rate (MAR) was measured from 0 to 14 d post inoculation (DPI) and 14 to 28 DPI using calcein injection. The microstructural architecture of the femur was analyzed using the Skyscan X-ray microtomography (microCT) on 6, 14, and 28 DPI. The results showed that the MAR decreased linearly with an increase in the challenged dose (P < 0.05) during 0 to 14 DPI. The results of microCT revealed that cortical and total BMD, BMC, bone volume (BV), and bone volume as a fraction of tissue volume (BV/TV) of femur decreased both linearly (P < 0.05). Conversely, the total number of pores increased linearly with an increase in challenge dosages on 6 and 14 DPI. Trabecular BMD, BV, BV/TV, trabecular number, and trabecular thickness decreased linearly with an increase in the challenge dosages (P < 0.05) on 6 DPI. Furthermore, Eimeria infection significantly increased the number of osteoclasts and osteoclastic activity (P=0.001). The result of this study suggests that the mixed Eimeria challenge negatively impacts the quality of skeletal health in a linear or quadratic manner with an increase in the concentration of Eimeria oocysts. The negative impact on long bone development might be due to malabsorption, nutrient deficiency during the infection, along with oxidative stress/inflammation disrupting the balance of osteoblastic and osteoclastic cells and their functions.

Sivelestat protects acute kidney injury by inhibiting the PI3K/AKT pathway in septic rats

To explore the protective effect of sivelestat (SV) against sepsis-induced acute kidney injury (AKI) and its molecular mechanism. According to the random number table method, 64 male Wistar rats were divided into sham operation group (Sham group), sepsis due to cecal ligation and puncture group (CLP group), low dose of SV treatment group (SL group, 50 mg/kg SV was injected into the tail vein at 12 hours and 24 hours after CLP), and high dose of SV treatment group (SH group, 100 mg/kg SV was injected into the tail vein at 12 hours and 24 hours after CLP), with 16 rats in each group. 48 hours after CLP, the 48-hour survival of rats were recorded, all rats were sacrificed and samples were harvested. Enzyme-linked immunosorbent assay (ELISA) was used to detect the serum levels of kidney injury molecule-1 (KIM-1), interleukins (IL-1β, IL-6), tumor necrosis factor-α (TNF-α) and neutrophil elastase (NE). Hematoxylin-eosin (HE) staining was used to observe histopathological changes and assess renal tubule injury score. Masson staining was used to detect the collagen volume fraction (CVF) of kidney tissue. Western blotting was used to detect the protein expressions of phosphatidylinositol 3-kinase (PI3K), phosphorylation PI3K (p-PI3K), protein kinase B (AKT), phosphorylation AKT (p-AKT), nuclear factor-κB p65 (NF-κB p65) and NE. The protein expressions of p-PI3K, p-AKT, NF-κB p65 were detected by immunohistochemistry. Compared with Sham group, the 48-hour survival rate of CLP group was significantly reduced. Histopathological results showed that large tubular epithelial cells and brush margins were shed, tubular casts were formed, some tubular atrophy, glomerular hyperemia, renal interstitial inflammatory cell infiltration and increased renal tubular injury score. Renal interstitial fibrosis was obvious and CVF increased. The levels of KIM-1, IL-1β, IL-6, TNF-α and NE in serum were significantly elevated in the CLP group. The proteins expression of inflammatory pathway-related p-PI3K/PI3K, p-AKT/AKT, NF-κB p65 and NE were significantly increased in kidney tissue. It suggested that septic rats had renal injury and the PI3K/AKT inflammatory pathway was activated. Compared with CLP group, there was no significant difference in 48-hour survival in SL group and SH group (68.75%, 75.00% vs. 56.25%, both P > 0.05), but kidney injury was significantly relieved. Specifically: renal tubular injury score and CVF significantly decreased [tubular injury score: 2 (1, 2), 1 (1, 1) vs. 2 (2, 3); CVF: (22.36±0.86)%, (18.74±1.05)% vs. (58.38±0.79)%, all P < 0.05]; the serum levels of KIM-1, IL-1β, IL-6, TNF-α and NE also decreased significantly [KIM-1 (ng/L): 145.03±8.88, 117.58±7.02 vs. 158.22±12.00; IL-1β (ng/L): 108.32±9.00, 92.98±8.06 vs. 133.78±8.48; IL-6 (ng/L): 124.33±10.11, 115.42±8.17 vs. 165.19±5.70; TNF-α (ng/L): 321.56±19.29, 289.68±21.57 vs. 424.88±22.76, NE (mol/L): 93.84±9.14, 75.01±10.56 vs. 113.45±6.39, all P < 0.05]; the proteins expression of inflammatory pathway-related p-PI3K/PI3K, p-AKT/AKT, NF-κB p65 and NE were significantly decreased (p-PI3K/PI3K: 0.93±0.06, 0.67±0.04 vs. 1.27±0.08; p-AKT/AKT: 0.78±0.09, 0.47±0.05 vs. 0.96±0.12; NF-κB p65/GAPDH: 1.43±0.13, 0.85±0.08 vs. 1.88±0.17; NE/GAPDH: 1.45±0.06, 0.91±0.04 vs. 1.71±0.08, all P < 0.05), the positive expressions of p-PI3K, p-AKT and NF-κB p65 in kidney tissue were decreased [p-PI3K positive expression area: (13.36±1.84)%, (8.03±1.12)% vs. (21.56±1.20)%; p-AKT positive expression area: (21.57±0.91)%, (15.21±2.76)% vs. (30.81±2.12)%; NF-κB p65 positive expression area: (25.17±1.38)%, (17.07±2.11)% vs. (37.85±2.50)%, all P < 0.05]. Serum inflammatory factor level, and PI3K/AKT pathway related protein, NF-κB p65, NE protein expression level and p-PI3K, p-AKT, NF-κB p65 positive area and other indicators in renal tissue in SH group were further lower than those in SL group (all P < 0.05). SV can ameliorate sepsis-induced AKI. The mechanism may be related to the inhibition of PI3K/AKT pathway, and high dose of SV has better efficacy.

Intensive systolic blood pressure treatment remodels brain perivascular spaces: A secondary analysis of the Systolic Pressure Intervention Trial (SPRINT)

BackgroundBrain perivascular spaces (PVS) are part of the glymphatic system and facilitate clearance of metabolic byproducts. Since enlarged PVS are associated with vascular health, we tested whether intensive systolic blood pressure (SBP) treatment affects PVS structure. MethodsThis is a secondary analysis of the Systolic PRessure INtervention Trial (SPRINT) MRI Substudy: a randomized trial of intensive SBP treatment to goal < 120 mm Hg vs < 140 mm Hg. Participants had increased cardiovascular risk, pre-treatment SBP 130–180, and no clinical stroke, dementia, or diabetes. Brain MRIs acquired at baseline and follow-up were used to automatically segment PVS in the supratentorial white matter and basal ganglia using a Frangi filtering method. PVS volumes were quantified as a fraction of the total tissue volume. The effects of SBP treatment group and major antihypertensive classes on PVS volume fraction were separately tested using linear mixed-effects models while covarying for MRI site, age, sex, Black race, baseline SBP, history of cardiovascular disease (CVD), chronic kidney disease, and white matter hyperintensities (WMH). ResultsFor 610 participants with sufficient quality MRI at baseline (mean age 67 ± 8, 40 % female, 32 % Black), greater PVS volume fraction was associated with older age, male sex, non-Black race, concurrent CVD, WMH, and brain atrophy. For 381 participants with MRI at baseline and at follow-up (median ± IQR = 3.9 ± 0.4 years), intensive treatment was associated with decreased PVS volume fraction relative to standard treatment (interaction coefficient: −0.029 [−0.055 to −0.0029] p = 0.029). Reduced PVS volume fraction was also associated with exposure to calcium channel blockers (CCB). ConclusionsPVS enlargement was partially reversed in the intensive SBP treatment group. The association with CCB use suggests that improved vascular compliance may be partly responsible. Improved vascular health may facilitate glymphatic clearance.Clincaltrials.gov: NCT01206062.

Pregnancies complicated by gestational diabetes and fetal growth restriction: an analysis of maternal and fetal body composition using magnetic resonance imaging.

Maternal body composition may influence fetal body composition. The objective of this pilot study was to investigate the relationship between maternal and fetal body composition. Three pregnant women cohorts were studied: healthy, gestational diabetes (GDM), and fetal growth restriction (FGR). Maternal body composition (visceral adipose tissue volume (VAT), subcutaneous adipose tissue volume (SAT), pancreatic and hepatic proton-density fat fraction (PDFF) and fetal body composition (abdominal SAT and hepatic PDFF) were measured using MRI between 30 to 36 weeks gestation. Compared to healthy and FGR fetuses, GDM fetuses had greater hepatic PDFF (5.2 [4.2, 5.5]% vs. 3.2 [3, 3.3]% vs. 1.9 [1.4, 3.7]%, p = 0.004). Fetal hepatic PDFF was associated with maternal SAT (r = 0.47, p = 0.02), VAT (r = 0.62, p = 0.002), and pancreatic PDFF (r = 0.54, p = 0.008). When controlling for maternal SAT, GDM increased fetal hepatic PDFF by 0.9 ([0.51, 1.3], p = 0.001). In this study, maternal SAT, VAT, and GDM status were positively associated with fetal hepatic PDFF.

Alveolar Repair Using Cancellous Bone and Beta Tricalcium Phosphate Seeded With Adipose-Derived Stem Cell.

Adipose-derived stem cells (ADSCs) have been subject of several studies due to their abundance, ease of preparation, and application in bone regeneration. We aim to compare effectiveness of alveolar reconstruction utilizing human cancellous freeze-dried graft (HCG) and beta tricalcium phosphate (BTP), both seeded with human ADSC (hADSC) and autologous bone graft (ABG). A 5 × 5 mm alveolar defect in 36 male Wistar rats were treated using: ABG (C), HCG-hADSC (H1), and BTP-hADSC (H2). At 1 and 8 weeks after surgery, runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osterix (OSX), and bone morphogenetic protein 2 (BMP2; g/mL) were quantified using immunohistochemistry, while bone tissue volume (BV, mm3), bone tissue volume fraction (BF, percentage), and trabecular thickness of bone (TT, mm) were assessed using micro-computed tomography (CT). One week after surgery, H2 was higher in RUNX2, OSX, ALP, and BMP2 than C (P < .05). Only RUNX2 and OSX were found to be higher in H1 than C, while ALP and BMP2 were higher in H2 than H1. Micro-CT revealed that H2 had a higher TT than C and C had a higher TT than H1 (P < .05). Eight weeks after surgery, both H2 and H1 was higher in RUNX2, OSX, ALP, and BMP2 than C (P < .05). RUNX2 and BMP2 were found to be higher in H1 than H2. Micro-CT revealed that H2 had higher BV and TT than C and H1 (P < .05). Exogenous hADSC strengthened the effectiveness of HCG and BTP to accelerate osteogenesis, osteoconduction, and osteoinduction. The latter was the most successful in bone formation, followed by HCG and ABG.

FTY720 administration results in a M2 associated immunoregulatory effect that positively influences the outcome of alveolar bone repair outcome in mice.

The alveolar bone repair process may be influenced by multiple local and systemic factors, which include immune system cells and mediators. Macrophages allegedly play important roles in the repair process, and the transition of an initial inflammatory M1 profile into a pro-reparative M2 profile theoretically contributes to a favorable repair outcome. In this context, considering immunoregulatory molecules as potential targets for improving bone repair, this study evaluated the role of the immunoregulatory molecule FTY720, previously described to favor the development of the M2 phenotype, in the process of alveolar bone healing in C57Bl/6 (WT) mice. Experimental groups submitted to tooth extraction and maintained under control conditions or treated with FTY720 were evaluated by microtomographic (μCT), histomorphometric, immunohistochemical and molecular analysis to characterize healing and host response features at 0, 1, 3, 7 and 14days. Our results demonstrated that the FTY720 group presented higher bone tissue density, higher bone tissue volume, greater tissue volume fraction, greater number and thickness of trabeculae and a higher number of osteoblasts and osteoclasts than the control group. Accordingly, the bone markers BMP2, BMP7, ALPL, SOST and RANK mRNA expressions increased in the FTY720 treated group. Furthermore, the levels of FIZZ, ARG2 and IL-10 mRNA increased in the FTY720 group together with the presence of CD206+ cells, suggesting that the boost of bone formation mediated by FTY720 involves an increased polarization and activity of M2 macrophages in healing sites. Thus, our results demonstrate that FTY720 favored the process of alveolar bone repair, probably trough a strengthened M2 response, associated with an increased expression of markers osteogenic differentiation and activity markers. Immunoregulatory strategies based in the modulation of macrophage polarization profile can comprise effective tools to improve the bone repair process.

Histomorphometry of Bone after Intentionally Exposed Non-Resorbable d-PTFE Membrane or Guided Bone Regeneration for the Treatment of Post-Extractive Alveolar Bone Defects with Implant-Supported Restorations: A Pilot Randomized Controlled Trial.

Aim: The aim of the present study was to investigate quantitative histological examination of bone reconstructed with non-resorbable high-density polytetrafluoroethylene membrane (d-PTFE), left intentionally exposed in post extraction sockets grafted with anorganic bone material, and removed after four weeks, versus extraction and guided bone regeneration (GBR), performed two months later. Materials and Methods: This study was designed as a multicenter randomized controlled trial of parallel-group design. Patients were selected and consecutively treated in three centers in Italy. Patients randomly received intentionally exposed non-resorbable d-PTFE membrane (group A), or guided bone regeneration (group B), to treat post-extractive alveolar bone defects with implant-supported restorations. Outcomes were: the implant failure, any mechanical and biological complications, patient satisfaction, and qualitative and histomorphometric evaluation of the collected bone samples. Results: Eighteen patients were consecutively enrolled in the trial. Of these, six out of 18 patients were male. All the included patients were treated according to the allocated interventions, and no drop out occurred. No implant failure and no complications were experienced, and all the patients were fully satisfied with the function and aesthetic of their implant-supported restoration, without difference between groups. Morphological analysis revealed no sign of tissue reaction, such as fibrosis or necrosis. Regenerated bone was well mineralized in both groups, but it seemed more mature in group B than in group A. Three samples showed a minimal number of lymphocytes. Several blood vessels of small size occupied the medullary spaces, where the tissue resulted in more maturity, indicating the activity of the tissue in progress. The histomorphometric evaluation showed no statistically significant differences in the tissue volume fractions between the two groups of patients. Conclusions: With the limitation of the present study, buccal plate reconstruction with an intentionally exposed non-resorbable membrane is an effective and easy procedure for regenerating a resorbed buccal bone plate, reducing the need for guided bone regeneration.

Temporal and spatial changes in bone mineral content and mechanical properties during breast-cancer bone metastases

Cancer cells favour migration and metastasis to bone tissue for 70–80 % of advanced breast cancer patients and it has been proposed that bone tissue provides attractive physical properties that facilitate tumour invasion, resulting in osteolytic and or osteoblastic metastasis. However, it is not yet known how specific bone tissue composition is associated with tumour invasion. In particular, how compositional and nano-mechanical properties of bone tissue evolve during metastasis, and where in the bone they arise, may affect the overall aggressiveness of tumour invasion, but this is not well understood. The objective of this study is to develop an advanced understanding of temporal and spatial changes in nano-mechanical properties and composition of bone tissue during metastasis. Primary mammary tumours were induced by inoculation of immune-competent BALB/c mice with 4T1 breast cancer cells in the mammary fat pad local to the right femur. Microcomputed tomography and nanoindentation were conducted to quantify cortical and trabecular bone matrix mineralisation and nano-mechanical properties. Analysis was performed in proximal and distal femur regions (spatial analysis) of tumour-adjacent (ipsilateral) and contralateral femurs after 3 weeks and 6 weeks of tumour and metastasis development (temporal analysis). By 3 weeks post-inoculation there was no significant difference in bone volume fraction or nano-mechanical properties of bone tissue between the metastatic femora and healthy controls. However, early osteolysis was indicated by trabecular thinning in the distal and proximal trabecular compartment of tumour-bearing femora. Moreover, cortical thickness was significantly increased in the distal region, and the mean mineral density was significantly higher in cortical and trabecular bone tissue in both proximal and distal regions, of ipsilateral (tumour-bearing) femurs compared to healthy controls. By 6 weeks post-inoculation, overt osteolytic lesions were identified in all ipsilateral metastatic femora, but also in two of four contralateral femora of tumour-bearing mice. Bone volume fraction, cortical area, cortical and trabecular thickness were all significantly decreased in metastatic femora (both ipsilateral and contralateral). Trabecular bone tissue stiffness in the proximal femur decreased in the ipsilateral femurs compared to contralateral and control sites. Temporal and spatial analysis of bone nano-mechanical properties and mineralisation during breast cancer invasion reveals changes in bone tissue composition prior to and following overt metastatic osteolysis, local and distant from the primary tumour site. These changes may alter the mechanical environment of both the bone and tumour cells, and thereby play a role in perpetuating the cancer vicious cycle during breast cancer metastasis to bone tissue.

Microstructural Deformations Within the Depth of the Lamina Cribrosa in Response to Acute In Vivo Intraocular Pressure Modulation.

PurposeThe lamina cribrosa (LC) is a leading target for initial glaucomatous damage. We investigated the in vivo microstructural deformation within the LC volume in response to acute IOP modulation while maintaining fixed intracranial pressure (ICP).MethodsIn vivo optic nerve head (ONH) spectral-domain optical coherence tomography (OCT) scans (Leica, Chicago, IL, USA) were obtained from eight eyes of healthy adult rhesus macaques (7 animals; ages = 7.9–14.4 years) in different IOP settings and fixed ICP (8–12 mm Hg). IOP and ICP were controlled by cannulation of the anterior chamber and the lateral ventricle of the brain, respectively, connected to a gravity-controlled reservoir. ONH images were acquired at baseline IOP, 30 mm Hg (H1-IOP), and 40 to 50 mm Hg (H2-IOP). Scans were registered in 3D, and LC microstructure measurements were obtained from shared regions and depths.ResultsOnly half of the eyes exhibited LC beam-to-pore ratio (BPR) and microstructure deformations. The maximal BPR change location within the LC volume varied between eyes. BPR deformer eyes had a significantly higher baseline connective tissue volume fraction (CTVF) and lower pore aspect ratio (P = 0.03 and P = 0.04, respectively) compared to BPR non-deformer. In all eyes, the magnitude of BPR changes in the anterior surface was significantly different (either larger or smaller) from the maximal change within the LC (H1-IOP: P = 0.02 and H2-IOP: P = 0.004).ConclusionsThe LC deforms unevenly throughout its depth in response to IOP modulation at fixed ICP. Therefore, analysis of merely the anterior LC surface microstructure will not fully capture the microstructure deformations within the LC. BPR deformer eyes have higher CTVF than BPR non-deformer eyes.

Regional differences in microarchitecture and mineralization of the atrophic edentulous mandible: A microcomputed tomography study

ObjectiveThe aim of the present study was to assess mineralization and trabecular microarchitecture in atrophic edentulous mandibles and to identify regional differences and relations with the extent of resorption. MethodsCortical and trabecular bone volumes in anterior, premolar and molar regions of 10 edentulous cadaveric mandibles (5 males and 5 females; mean age ± SD: 85.4 ± 8.3 years) were assessed by microcomputed tomography. Mandibular height and Cawood & Howell classes were recorded. Concerning trabecular volumes, bone mineral density (BMD), bone volume fraction, trabecular tissue volume fraction, connectivity density, trabecular number, trabecular thickness, trabecular separation, degree of anisotropy, and structural model index were measured; concerning cortical volumes porosity, BMD and cortical thickness were measured. ResultsIn molar regions, the bone volume fraction and trabecular number were lower, whereas trabecular separation, degree of anisotropy and cortical BMD were higher compared to anterior regions. In premolar regions, mandibular height correlated negatively with trabecular number (Spearman’s correlation r = 0.73, p = 0.017) and connectivity density (Spearman’s correlation r = 0.82, p = 0.004), and correlated positively with trabecular separation (Spearman’s correlation r = − 0.65, p = 0.04). Cortical BMD was higher at bucco-inferior cortex of molar and inferior border of premolar region and lower at anterior cranial buccal and lingual surface. ConclusionsIn the premolar region, increased resorption coincides with local impairment of trabecular bone quality. Cortical bone BMD is higher in areas with highest strains and lower in areas with most mandibular resorption. Trabecular bone volume and quality is superior in the anterior region of the edentulous mandible, which might explain improved primary stability of dental implants in this region.

Інвазивна та неінвазивна діагностика фіброзу підшлункової залози у хворих з ускладненими формами хронічного панкреатиту

The purpose of the study was to identify the patterns of changes in the state of the parenchyma of the pancreas in patients with complicated forms of chronic pancreatitis with evaluation of the diagnostic effectiveness of shear wave elastometry (graphy). Materials and methods. For the period from 2006 to 2018 58 patients with complicated forms of chronic pancreatitis were examined. The average age of patients is (47.1±3.2) years old. The medical history ranged from 3 to 15 years. The basis of morphological studies were biopsies of the pancreas obtained during surgery. Ultrasound elastometry and pancreatic parenchymal elastography were performed by transcutaneous shear wave approach in Shear Wave Elastography. Software consistency was assessed by the nature of the color mapping. Results and discussion. The morphometry of the volume parts of the structural components of the pancreas showed that with the development of complicated chronic pancreatitis there is an increase in the area of fibrous tissue and a decrease in the area of acinar components. The proof of this is the strong inverse relationship between the degree of fibrosis and the volume fraction of acinar tissue (r= -0.83; р &lt;0.05), as well as the direct relationship between the degree of fibrosis and the volume fraction of connective tissue (r=0.61; р &lt;0.05). If at a fibrosis of the III degree acinar tissue occupied (25.39±2.01)%, connective – (64.33±3.85)%, fatty – (6.42±4.48)%, at a fibrosis of the IV degree noted the following: the proportion of acinar tissue was only (2.86±0.76)%, connective – (74.11±4.17)%, and (20.14±4.29)% was adipose tissue. Such manifestations indicated severe irreversible changes in the external secretory function of the pancreas. When assessing changes in the stiffness of the pancreatic parenchyma with the deepening of fibrosis processes and data from transcutaneous shear wave elastography, it was found that the degree of fibrosis according to morphological data correlated with the degree of fibrosis according to shear wave elastography, r = 0.71; p &lt;0.05. The following patterns were noted. Grade II pancreatic fibrosis was characterized by intralobular fibrosis, which covered 26-50% of the gland area, which corresponded to the shear wave elastography data in green-blue color (5.98-7.05 kPa). Grade III pancreatic fibrosis corresponded to intralobular fibrosis, which covered 51-75% of the gland area in shear wave elastography in green-yellow color (7.06-9.06 kPa). Grade IV pancreatic fibrosis was characterized by intralobular fibrosis, which covered 76-100% of the gland area, which corresponded to shear wave elastography data in yellow-red color (&gt; 9.07 kPa). Conclusion. Thus, the objectification of shear wave elastography indicators of the pancreas based on the correlation of histological evaluation and morphometric indicators of structural changes in the pathological process allows to consider transcutaneous shear wave elastography as a promising and reliable method of non-invasive diagnosis of fibrosis in chronic pancreatitis

IGF-1 TMJ injections enhance mandibular growth and bone quality in juvenile rats.

Dentofacial orthopaedic treatment of mandibular hypoplasia has unpredictable skeletal outcomes. Although several biomodulators including insulin-like growth factor 1 (IGF-1) are known to contribute to chondrocyte proliferation, their efficacy in modulating mandibular growth has not been validated. The aim of this study was to determine the effect of locally delivered IGF-1 on mandibular growth and condylar bone quality/quantity in juvenile rats. Institutional vivarium using twenty-four 35-day-old male Sprague-Dawley rats. PBS or 40µg/kg (low-dose) IGF-1 or 80µg/kg (high-dose) IGF-1 was injected bilaterally into the temporomandibular joints of the rats at weekly intervals for four weeks. Cephalometric and micro-computed tomography measurements were used to determine mandibular dimensions. Bone and tissue mineral density, volume fraction and mineral content were determined, and serum IGF-1 concentrations assayed. Intra-articular administration of high-dose IGF-1 contributed to a significant 6%-12% increase in mandibular body and condylar length compared to control and low-dose IGF-1-treated animals. Additionally, IGF-1 treatment resulted in a significant decrease in the angulation of the lower incisors to mandibular plane. Condylar bone volume, bone volume fraction, mineral content and mineral density were significantly increased with high-dose IGF-1 relative to control and low-dose IGF-1 groups. Serum IGF-1 levels were similar between all groups confirming limited systemic exposure to the locally administered IGF-1. Local administration of high-dose 80µg/kg IGF-1 enhances mandibular growth and condylar bone quality and quantity in growing rats. The findings have implications for modulating mandibular growth and potentially enhancing condylar bone health and integrity.

Small Airway Reduction and Fibrosis Is an Early Pathologic Feature of Idiopathic Pulmonary Fibrosis.

Rationale: To improve disease outcomes in idiopathic pulmonary fibrosis (IPF), it is essential to understand its early pathophysiology so that it can be targeted therapeutically. Objectives: Perform three-dimensional assessment of the IPF lung microstructure using stereology and multiresolution computed tomography (CT) imaging. Methods: Explanted lungs from patients with IPF (n = 8) and donor control subjects (n = 8) were inflated with air and frozen. CT scans were used to assess large airways. Unbiased, systematic uniform random samples (n = 8/lung) were scanned with microCT for stereological assessment of small airways (count number, and measure airway wall and lumen area) and parenchymal fibrosis (volume fraction of tissue, alveolar surface area, and septal wall thickness). Measurements and Main Results: The total number of airways on clinical CT was greater in IPF lungs than control lungs (P < 0.01), owing to an increase in the wall (P < 0.05) and lumen area (P < 0.05) resulting in more visible airways with a lumen larger than 2 mm. In IPF tissue samples without microscopic fibrosis, assessed by the volume fraction of tissue using microCT, there was a reduction in the number of the terminal (P < 0.01) and transitional (P < 0.001) bronchioles, and an increase in terminal bronchiole wall area (P < 0.001) compared with control lungs. In IPF tissue samples with microscopic parenchymal fibrosis, terminal bronchioles had increased airway wall thickness (P < 0.05) and dilated airway lumens (P < 0.001) leading to honeycomb cyst formations. Conclusions: This study has important implications for the current thinking on how the lung tissue is remodeled in IPF and highlights small airways as a potential target to modify IPF outcomes.