Search

The influences of trait diversity (i.e., the niche complementarity effect) and functional composition (i.e., the mass ratio effect) on aboveground biomass (AGB) is a highly debated topic in forest ecology. Therefore, further studies are needed to explore these mechanisms in unstudied forest ecosystems to enhance our understanding, and to provide guidelines for specific forest management. Here, we hypothesized that functional composition would drive AGB better than trait diversity and stem size inequality in the (sub-) tropical forests of Nepal. Using data from 101 forest plots, we tested 25 structural equation models (SEMs) to link elevation, stem DBH inequality, trait diversity (i.e., trait richness, evenness, dispersion and divergence), functional composition [i.e., community-weighted of maximum height mean (CWM of Hmax), specific leaf area (CWM of SLA), leaf dry matter content (CWM of LDMC), and wood density (CWM of WD)] and AGB. The best-fitted SEMs indicated that CWM of Hmax promoted AGB while overruling the impacts of trait diversity indices on AGB. However, low trait diversity indices were linked with higher AGB while overruling the effects of CWM of SLA, LDMC and WD on AGB. In addition, AGB decreased with increasing elevation, whereas stem size inequality did not influence AGB. Our results suggest that divergent species’ functional strategies could shape AGB along an altitudinal gradient in tropical forests. We argue that forest management practices should include plant functional traits in the management plan for the co-benefits of biodiversity conservation and carbon sequestration that underpins human wellbeing.

The objective of the study was to predict of Libero’s performance on the basis of selected anthropometric characteristics. In this study, Libero’s performance was selected as dependent variable (DV) and selected anthropometric characteristics i.e. LP (Libero’s Performance), LH (Libero’s Height), LW (Libero’s Weight), LAL (Libero’s Arm Length), LFAL (Libero’s Fore Arm Length, LUAL (Libero’s Upper Arm Length), LUAC (Libero’s Upper Arm Circumference), LWC (Libero’s Waist Circumference), LHC (Libero’s Hip Circumference), LLL (Libero’s Leg Length), LLLL (Libero’s Lower Leg Length), LTC (Libero’s Thigh Circumference) and LCC (Libero’s Calf Circumference) were observed as independent variables (IV). For the purpose of the present study, the subjects were selected from Inter-university level Volleyball Tournament. A total of 75 male Liberos were purposively selected for the study. The age of the subjects ranged between 18-28 years. To find out relationship between Dependent Variable (Libero’s Performance) and Independent Variables (selected Anthropometric Characteristics), Product Moment correlation and multiple correlations were applied. For predicting Dependent Variable (Libero’s Performance) on the basis of Independent Variables (selected Anthropometric Characteristics), multiple regression equation was applied. Established regression models are: (1) Libero’s Performance = 114.163-551X Libero’s Height (2) Libero’s Performance = 137.345 -1.171 X Libero’s Height+.913 X Libero’s Leg Length (3) Libero’s Performance = 95.165 -.944 X Libero’s Height+1.296 X Libero’s Leg Length -1.024 X Libero’s Calf Circumference. The findings suggest that performance is associated with anthropometric characteristics with biomechanical implications that may be used to provide a more complete evaluation of Libero’s performance.

Funder: Agua Salud Project, Funder: U.S. Department of Energy; Id: http://dx.doi.org/10.13039/100000015, Funder: CAPES; Id: http://dx.doi.org/10.13039/501100002322, Data capturing multiple axes of tree size and shape, such as a tree's stem diameter, height and crown size, underpin a wide range of ecological research-from developing and testing theory on forest structure and dynamics, to estimating forest carbon stocks and their uncertainties, and integrating remote sensing imagery into forest monitoring programmes. However, these data can be surprisingly hard to come by, particularly for certain regions of the world and for specific taxonomic groups, posing a real barrier to progress in these fields. To overcome this challenge, we developed the Tallo database, a collection of 498,838 georeferenced and taxonomically standardized records of individual trees for which stem diameter, height and/or crown radius have been measured. These data were collected at 61,856 globally distributed sites, spanning all major forested and non-forested biomes. The majority of trees in the database are identified to species (88%), and collectively Tallo includes data for 5163 species distributed across 1453 genera and 187 plant families. The database is publicly archived under a CC-BY 4.0 licence and can be access from: https://doi.org/10.5281/zenodo.6637599. To demonstrate its value, here we present three case studies that highlight how the Tallo database can be used to address a range of theoretical and applied questions in ecology-from testing the predictions of metabolic scaling theory, to exploring the limits of tree allometric plasticity along environmental gradients and modelling global variation in maximum attainable tree height. In doing so, we provide a key resource for field ecologists, remote sensing researchers and the modelling community working together to better understand the role that trees play in regulating the terrestrial carbon cycle.

Background and aims The measurement of the skinfold thickness at various sites with the calipers has remained the traditional method for estimation of body fat percentage (%BF) in clinical practice. Although this technique is relatively inexpensive and easy to learn, there are more chances of errors while measuring the skinfold thickness by this method. Therefore, no single standard prediction formula for the determination of body fat could be fixed. The aim of our study was to use B-mode ultrasound (US) for measuring the subcutaneous fat thickness and the calipers for skinfold thickness, and then compare, correlate, and derive the prediction equations for estimation of %BF by both the techniques. Methods This cross-sectional, observational, monocentric study was conducted on 43 Indian male volunteers aged 18 to 40 years. After collecting anthropometric data (age, height, weight, body mass index, waist circumference, hip circumference, waist-to-hip ratio [WHR], etc.), the skinfold thickness was measured at four standard sites (biceps, triceps, subscapular region, and suprailiac region) with skinfold caliper (SFC) and then B-mode US. The data were analyzed for distribution, and independent t-test was applied to compare the difference between two means of a %BF estimated by both the methods. The prediction equations were developed from anthropometric and skinfold thickness data obtained from both the methods, i.e., SFC and US, by applying stepwise multiple linear regression. Results It was observed that mean values of all the skinfold thicknesses along with the %BF measured by SFC were far more than those measured by US. The %BF measured by US technique (%BF US) was significantly lesser, i.e., 20.69 (SD: 3.126; p0.0002), than that of the SFC method (%BF SFC), i.e., 30.38 (SD: 4.634), which is 0.68 % higher. The best prediction equation for the %BF by SFC method was [%BF SFC = -26.154 + 0.208 SFss + 0.374 age + 0.354 SFbi + 32.066 WHR] (R

The existing information on tobacco control, though highly valuable, is lying scattered at different sources. Post Graduate Institute of Medical Education and Research (PGIMER) Chandigarh in collaboration and technical support of International Union against TB and Lung Diseases (The Union) undertook an initiative to start a national level E-Resource Centre for Tobacco Control (E-RCTC) with an aim to provide relevant information on tobacco control under one roof thereby countering the misleading facts on tobacco control which exist on various web engines. The national level E-Resource Centre for Tobacco Control was developed in three stages. In the span of less than 3 years, the portal is open in public domain with over 2,36,019 visitors from around 80+ countries (as on 23rd July 2020), and growing. The portal showcases an array of valuable and vital information related to tobacco control initiatives under various heads like: Policies and Legislations, Circulars and Orders, National Tobacco Control Programme (NTCP), Publications and IEC Materials. India's first national level Resource Centre for Tobacco Control has proved to be a much-needed step in the country for facilitating speedy implementation of World Health Organization- Framework Convention on Tobacco Control (WHO-FCTC), MPOWER and other tobacco control interventions. Even with its limitations like absence of an interactive mechanism among a few others, the Resource Centre is nothing less than a storehouse of knowledge as it showcases content that are immensely helpful for the tobacco control community. Constant efforts are being made to improve the national level E-Resource Centre for Tobacco Control website and minimize the drawbacks.

In forest ecosystems, it is debated which measure of biodiversity should better explain aboveground biomass (AGB). Here, we hypothesized that high species richness, evolutionary diversity and individual tree size variation drive higher AGB in tropical forests but dependent on local-scale tropical forest types. For this, we analyzed the data of 101 plots (each 0.05 ha in size) across three local-scale tropical forest types (i.e., tropical evergreen and deciduous forest, sub-tropical coniferous forest, and tropical evergreen and mixed hardwood forest) of western Nepal. We used structural equation models to examine the multiple multivariate relationships amongst elevation, species richness, evolutionary diversity [either phylogenetic species evenness (PSE), phylogenetic species variability (PSV) or phylogenetic species clustering (PSC)], individual tree diameter at breast height (DBH) variation, and AGB in all forests together and across forest types. We found that phylogenetically close species enhanced AGB in all forests together, particularly in tropical evergreen and deciduous forest, and sub-tropical coniferous forest. However, both phylogenetically close and distant species were responsible for higher AGB in tropical evergreen and mixed hardwood forest. The coexistence of phylogenetically close species at different abundances and high phylogenetic variability in species with higher species richness collectively enhanced AGB in the lowland tropical forests due to the niche diversification. However, AGB was mostly explained by phylogenetically close species with unequal abundances at higher elevation areas, which may be due to the selection effects. Interestingly, tree DBH variation possessed a negligible effect on AGB in studied tropical forests. We recommend to use evolutionary diversity indices in the future development of forest management plans where aboveground carbon sequestration is a priority objective.

Both ovarian cancer and idiopathic pulmonary fibrosis (IPF) are accompanied by significant collagen remodeling in the respective extracellular matrix (ECM). These diseases have similar attributes and collagen alterations can be probed with the same methods. Remodeling can be reflected in increased collagen concentration, changes in alignment within fibrils and fibers and/or up-regulation of different collagen isoforms. We used pixel-based SHG polarization analyses to discriminate the macro/supramolecular collagen structure in human tissues by: i) determination of the helical pitch angle via the single axis molecular model, ii) dipole alignment within fibrils via anisotropy, and iii) chirality via SHG circular dichroism (SHG-CD). For ovarian cancer, the largest differences were between normal stroma and benign tumors, consistent with gene expression showing Col III is up-regulated in the latter. The tissues also displayed differing SHG anisotropies and SHG-CD responses, consistent with randomization of Col I alignment in fibrils in all tumors. These results collectively indicate the fibril assemblies are distinct in all ovarian tissues and likely result from synthesis of new collagen rather than remodeling of existing collagen. For IPF, the largest change was in the SHG-CD response, indicating the fibrotic collagen has different helical structure than that of normal tissues. Interestingly, for both diseases, no increase in Col IIII was found, in contrast to previous reports by immunostaining. We suggest these polarization-based metrics could form the basis of a new classification scheme and complement conventional classification based on genetic profiles and conventional histology for these diseases as well as other cancers and fibroses.

Collagen remodeling occurs in many prostate pathologies; however, the underlying structural architecture in both normal and diseased prostatic tissues is largely unexplored. Here, we use second-harmonic generation (SHG) microscopy to specifically probe the role of the proteoglycan decorin (Dcn) on collagen assembly in a wild type (wt) and Dcn null mouse (Dcn − / − ). Dcn is required for proper organization of collagen fibrils as it regulates size by forming an arch-like structure at the end of the fibril. We have utilized SHG metrics based on emission directionality (forward–backward ratio) and relative conversion efficiency, which are both related to the SHG coherence length, and found more disordered fibril organization in the Dcn − / − . We have also used image analysis readouts based on entropy, multifractal dimension, and wavelet transforms to compare the collagen fibril/fiber architecture in the two models, where all these showed that the Dcn − / − prostate comprised smaller and more disorganized collagen structures. All these SHG metrics are consistent with decreased SHG phase matching in the Dcn − / − and are further consistent with ultrastructural analysis of collagen in this model in other tissues, which show a more random distribution of fibril sizes and their packing into fibers. As Dcn is a known tumor suppressor, this work forms the basis for future studies of collagen remodeling in both malignant and benign prostate disease.

The accepted mechanism explaining the accelerated growth following periosteal resection is that the periosteum serves as a mechanical restraint to restrict physeal growth. To test the veracity of this mechanism we first utilized Second Harmonic Generation (SHG) imaging to measure differences of periosteal fiber alignment at various strains. Additionally, we measured changes in periosteal growth factor transcription. Next we utilized SHG imaging to assess the alignment of the periosteal fibers on the bone both before and after periosteal resection. Based on the currently accepted mechanism, we hypothesized that the periosteal fibers adjacent to the physis should be more aligned (under tension) during growth and become less aligned (more relaxed) following metaphyseal periosteal resection. In addition, we measured the changes in periosteal micro- and macro-scale mechanics.30 seven-week old New Zealand White rabbits were sacrificed. The periosteum was imaged on the bone at five regions using SHG imaging. One centimeter periosteal resections were then performed at the proximal tibial metaphyses. The resected periosteal strips were stretched to different strains in a materials testing system (MTS), fixed, and imaged using SHG microscopy. Collagen fiber alignment at each strain was then determined computationally using CurveAlign. In addition, periosteal strips underwent biomechanical testing in both circumferential and axial directions to determine modulus, failure stress, and failure strain. Relative mRNA expression of growth factors: TGFβ-1, -2, -3, Ihh, PTHrP, Gli, and Patched were measured following loading of the periosteal strips at physiological strains in a bioreactor. The periosteum adjacent to the physis of six tibiae was imaged on the bone, before and after, metaphyseal periosteal resection, and fiber alignment was computed. One-way ANOVA statistics were performed on all data.Imaging of the periosteum at different regions of the bone demonstrated complex regional differences in fiber orientation. Increasing periosteal strain on the resected strips increased periosteal fiber alignment (p0.0001). The only exception to this pattern was the 10% strain on the tibial periosteum, which may indicate fiber rupture at this non-physiologic strain. Periosteal fiber alignment adjacent to the resection became less aligned while those adjacent to the physes remained relatively unchanged before and after periosteal resection. Increasing periosteal strain on the resected strips increased periosteal fiber alignment (p0.0001). The only exception to this pattern was the 10% strain on the tibial periosteum, which may indicate fiber rupture (and consequent retraction) at this non-physiologic strain. Increasing periosteal strain revealed a significant increase in relative mRNA expression for Ihh, PTHrP, Gli, and Patched, respectively.Periosteal fibers adjacent to the growth plate do not appear under tension in the growing limb, and the alignments of these fibers remain unchanged following periosteal resection.The results of this study call into question the long-accepted role of the periosteum acting as a simple mechanical tether restricting growth at the physis.

Disruption of the periosteum has been used to explain overgrowth after long bone fractures. Clinically, various periosteal procedures have been reported to accelerate growth with varied results. Differences between procedures and study populations, in these prior studies, make drawing conclusions regarding their effectiveness difficult. The purpose of this study was to (1) determine if all reported periosteal procedures accelerate growth and increase the length of bones; (2) study the relative duration of these growth-accelerating effects at two time points; and (3) identify the periosteal procedure that results in the most growth. Periosteal stripping (N = 8), periosteal transection (N = 8), periosteal resection (N = 8), (and) full periosteal release (N = 8) were performed on the tibiae of skeletally immature rabbits. Tibiae were collected 2 weeks postoperatively. The tibiae of additional cohorts of periosteal transection (N = 8), periosteal resection (N = 8), full periosteal release (N = 8), and repetitive periosteal transection (N = 8) were collected 8 weeks postoperatively. The contralateral tibiae served as an operative sham control in all cohorts. Fluorochrome bone labeling was used to measure growth rates, whereas high-resolution Faxitron imaging was performed to measure tibial lengths. Comparisons were then made between (1) experimental and sham controls; and (2) different procedures. Eight additional nonsurgical animals were included as age-matched controls. Growth (in microns) was accelerated at the proximal tibial physis on the tibia undergoing the periosteal surgical procedures versus the contralateral control limb after the transection (411 ± 27 versus 347 ± 18, p < 0.001 [mean ± SD]), resection (401 ± 33 versus 337 ± 31, p < 0.001), and full periosteal release (362 ± 45 versus 307 ± 33, p < 0.001), 2 weeks after the index procedure. Conversely, the periosteal stripping cohort trended toward less growth (344 ± 35) than the controls (356 ± 25; p = 0.08). No differences were found between limbs in the nonoperative controls. Tibial lengths for the experimental tibiae were longer at 2 weeks in the transection (1.6 ± 0.4 mm, p < 0.001), resection (1.6 ± 0.9 mm, p = 0.03), and full periosteal release (1.7 ± 0.5 mm, p < 0.001), whereas negligible differences were found between the tibiae of the nonoperative controls (0.13 ± 0.7 mm, p = 0.8) and stripping cohorts (0.10 ± 0.6 mm, p = 0.7). At 8 weeks, growth acceleration ceased at the proximal tibial physes in the transection cohort (174 ± 11 versus 176 ± 21, p = 0.8), and the control limbs actually grew faster than the experimental limbs after resection (194 ± 24 versus 178 ± 23, p = 0.02) and full periosteal release (193 ± 16 versus 175 ± 19, p < 0.01) cohorts. Growth rates were increased over control limbs, only in the repetitive transection cohort (190 ± 30 versus 169 ± 19, p = 0.01) at 8 weeks. Tibial lengths for the experimental tibiae remained longer at 8 weeks in the transection (1.4 ± 0.70 mm, p < 0.001), resection (2.2 ± 0.82 mm, p < 0.001), full periosteal release (1.6 ± 0.42 mm, p < 0.001), and repetitive periosteal transection (3.3 ± 1.1 mm, p < 0.001), whereas negligible differences were found between the tibiae of the nonoperative controls (−0.08 ± 0.58 mm, p = 0.8). Comparing the procedures at 2 weeks postoperatively, no differences were found in tibial lengths among the transection (2.1% ± 0.5% increase), resection (2.1% ± 1.1% increase), and full periosteal release (2.1% ± 0.6 %); however, all three demonstrated greater increased growth when compared with the stripping cohort (−0.10% ± 0.7%; p < 0.05). At 8 weeks no differences could be found between increased tibial lengths among the transection (1.5% ± 0.7%), resection (2.3% ± 0.9%), and full periosteal release (1.7% ± 0.4%). The repetitive transection produced the greatest over length increase (3.5% ± 1%), and this was greater than the acceleration generated by the single resection (p < 0.001) or the full periosteal release (p = 0.001). All four demonstrated an increase greater than the nonoperative control (0.09% ± 0.6%; p < 0.05). Transection of the longitudinally oriented periosteal fibers appears critical to accelerate growth in a rabbit model. These findings in an animal model support previous claims that limb overgrowth occurs as the result of periosteal disruption. Based on these findings in rabbits, we believe that less invasive procedures like periosteal transection are a promising avenue to explore in humans; clinical studies should seek to determine whether it is equally effective as more invasive procedures and its role as an adjunct to guided growth or distraction osteogenesis.

BACKGROUND The purpose of this study was to explore the role of perinatal vitamin-D intake on the development and characterization of hyperkyphosis in a porcine model. METHODS The spines of 16 pigs were assessed at 9, 13, and 17 weeks of age with radiography and at 17 weeks with computed tomography (CT), magnetic resonance imaging (MRI), histology, and bone-density testing. An additional 169 pigs exposed to 1 of 3 maternal dietary vitamin-D levels from conception through the entire lactation period were fed 1 of 4 nursery diets supplying different levels of vitamin D, calcium, and phosphorus. When the animals were 13 weeks of age, upright lateral spinal radiography was performed with use of a custom porcine lift and sagittal Cobb angles were measured in triplicate to determine the degree of kyphosis in each pig. RESULTS The experimental animals had significantly greater kyphotic sagittal Cobb angles at all time points when compared with the control animals. These hyperkyphotic deformities demonstrated no significant differences in Hounsfield units, contained a slightly lower ash content (46.7% ± 1.1% compared with 50.9% ± 1.6%; p < 0.001), and demonstrated more physeal irregularities. Linear mixed model analysis of the measured kyphosis demonstrated that maternal diet had a greater effect on sagittal Cobb angle than did nursery diet and that postnatal supplementation did not completely eliminate the risk of hyperkyphosis. CONCLUSIONS Maternal diets deficient in vitamin D increased the development of hyperkyphosis in offspring in this model. CLINICAL RELEVANCE This study demonstrates that decreased maternal dietary vitamin-D intake during pregnancy increases the risk of spinal deformity in offspring. In addition, these data show the feasibility of generating a large-animal spinal-deformity model through dietary manipulation alone.

The extracellular matrix of articular cartilage is a complex network of type II collagen, proteoglycan, and water.1 Quantitative magnetic resonance imaging (MRI) methods have been used to evaluate the composition and ultrastructure of articular cartilage.2 Among these techniques, the transverse relaxation time constant (T2) has been the most extensively studied and has been shown to be sensitive for detecting cartilage degeneration.3,4 However, T2 relaxation time is a nonspecific parameter influenced by multiple factors including tissue anisotropy, hydration, and macromolecule content.5–7 Multicomponent T2 mapping methods have been proposed to improve the specificity of cartilage T2 analysis.8–10 Previous studies using nuclear magnetic resonance (NMR) have identified three water components within cartilage, which were assigned to extremely fast-relaxing water bound to collagen (T2 = 2 msec, fraction = 6%), fast-relaxing water bound to proteoglycan (T2 = 25 msec, fraction = 15%), and slow-relaxing bulk water (T2 = 96 msec, fraction = 79%).8 Multicomponent T2 analysis is typically performed using multiecho spin-echo techniques.8–10 Previous studies have shown that the fraction of the fast-relaxing water component (FF) is a sensitive and specific measure of the proteoglycan content of cartilage and that the T2 relaxation time of both the fast-relaxing (T2F) and slow-relaxing (T2S) water components change with enzymatic degradation of cartilage.8,9 However, spin-echo techniques require a long acquisition time, which have limited cartilage assessment to a single slice of ex vivo specimens. An alternative method called Multicomponent Driven Equilibrium Single Pulse Observation (mcDESPOT) has recently been proposed to accelerate multicomponent T2 analysis using rapid 3D steady-state imaging.11,12 mcDESPOT can be used to characterize the fast-and slow-relaxing water components of articular cartilage with complete anatomic coverage of the human knee joint at 3.0T in a clinically feasible scan time.12–14 One confounding factor in the two-pool mcDESPOT analysis is synovial fluid partial volume averaging with superficial cartilage. The extremely slow-relaxing synovial fluid water (T2 in the range of seconds) can cause a significant increase in T2 relaxation time as well as an underestimation of the water fraction of the fast-relaxing water component.15 Thus, there is a need to account for synovial fluid in the mcDESPOT model to better assess superficial cartilage and to avoid biased multicomponent T2 measurements. Three-pool models have been recently proposed for mcDESPOT15 and quantitative magnetization transfer (MT) imaging16 to improve the characterization of neural tissues in the presence of partial volume averaging with cerebrospinal fluid (CSF). Specifically, a mcDESPOT three-pool method introduces a third nonexchanging water component to model the partial volume averaging effects of CSF, which has been shown to be effective at correcting CSF contamination in brain imaging.15 This study was performed to investigate the use of the three-pool mcDESPOT model to account for the confounding effects of synovial fluid on multicomponent T2 analysis of the articular cartilage of the knee joint in human subjects.

The collagen structure throughout the patella has not been thoroughly investigated by 3D imaging, where the majority of the existing data come from histological cross sections. It is important to have a better understanding of the architecture in normal tissues, where this could then be applied to imaging of diseased states.To address this shortcoming, we investigated the combined use of collagen-specific Second-Harmonic Generation (SHG) imaging and measurement of bulk optical properties to characterize collagen fiber orientations of the histologically defined zones of bovine articular cartilage. Forward and backward SHG intensities of sections from superficial, middle and deep zones were collected as a function of depth and analyzed by Monte Carlo simulations to extract the SHG creation direction, which is related to the fibrillar assembly.Our results revealed differences in SHG forward-backward response between the three zones, where these are consistent with a previously developed model of SHG emission. Some of the findings are consistent with that from other modalities; however, SHG analysis showed the middle zone had the most organized fibril assembly. While not distinct, we also report bulk optical property values for these different zones within the patella.Collectively, these results provide quantitative measurements of structural changes at both the fiber and fibril assembly of the different cartilage zones and reveals structural information not possible by other microscope modalities. This can provide quantitative insight to the collagen fiber network in normal cartilage, which may ultimately be developed as a biomarker for osteoarthritis.

Remodeling of the extracellular matrix in human ovarian cancer, can be reflected in increased collagen concentration, changes in alignment and/or up-regulation of different collagen isoforms, including Col III. Using fibrillar gel models, we demonstrate that Col I and Col III can be quantitatively distinguished by 3 distinct SHG polarization specific metrics: i) determination of helical pitch angle via the single axis molecular model, ii) dipole alignment via anisotropy, and iii) chirality via SHG circular dichroism (SHG-CD). These sub-resolution differentiations are possible due to differences in the α helix angles of the two isoforms, which co-mingle in the same fibrils. We also investigated the mechanism of the SHG-CD response and show that unlike conventional CD, it is dominated by electric dipole interactions and is consistent with the two state SHG model. We further applied these 3 polarization resolved analyses to human normal, high risk, benign tumors, and malignant human ovarian tissues. We found that these tissues could all be differentiated by these metrics, where high grade tissues had analogous α-helical pitch angles to the in the Col I/Col III gel model. This confirms literature suggestions based on immunofluorescence and gene expression that Col III is up-regulated in high grade ovarian cancers. The different tissues also displayed differing anisotropies, indicating the fibril assemblies are distinct and likely do not result from remodeling of existing collagen but synthesis of new collagen. Importantly, these SHG polarization methods provide structural information not otherwise possible and can serve as label-free biomarkers for ovarian and other cancers.

Previous studies have shown that bone growth acceleration can occur in many animal species after periosteal resection (removal of a strip of periosteum) with minimum morbidity. This has numerous clinical applications, including treatment of limb length differences. Here we use Second Harmonic Generation (SHG) imaging microscopy to evaluate changes in collagen architecture reflective of the different strains the periosteum may encounter during bone growth. Specifically, we image rabbit tibial periosteum strips at -20%, 0%, 5%, and 10% strains. We first quantify these changes using the SHG creation ratio (Forward/Backward) or the initially emitted SHG directionality to provide information on the fibril level of assembly. The in situ (i.e. physiological) strain had the highest creation ratio compared to the non-in situ strains of -20%, 5%, and 10%, which were shown to be significantly different via RCBD statistical analysis. These trends are consistent with SHG phasematching considerations, where more organized fibrils/fibers result in primarily forward emitted components, which here is the physiological strain. We further use the relative SHG conversion efficiency to assess the tissue structure under strain, where this results from the combination of collagen concentration and organization. The 0% strain SHG conversion efficiency was significantly higher than all other strains, where this is expected as the fibers have the highest local density and organization, and is consistent with the emission directionality results. Importantly, due to the underlying physical process, the label-free SHG imaging modality can non-invasively monitor the effect of treatments for bone growth and other orthopedic disorders.

PURPOSE: Significant remodeling of the extracellular matrix (ECM) occurs in human ovarian cancer and has been observed in both high grade and low grade tumors as well as ovaries from high risk patients with BRCA mutations. Uniquely quantifying alterations in the tumor microenvironment (TME) could be used as a new diagnostic tool, e.g. to complement histology; provide insight into disease etiology; and assess treatment efficacy through minimally invasive in vivo imaging. Current clinical modalities (CT, MRI, PET) lack the resolution for this purpose. Our efforts have focused on examining collagen alterations across a spectrum of human ovarian tumors, where the changes can serve as quantitative biomarkers. Alterations can be reflected in increased collagen concentration, changes in alignment of collagen molecules within fibrils and/or fibers and/or up-regulation of different collagen isoforms, e.g. Col III. METHODS AND RESULTS: We used the collagen specific/sensitive Second Harmonic Generation (SHG) imaging microscopy to probe collagen architecture over size scales that range from the macromolecular structural properties to fibril/fiber morphology. First, we used SHG polarization analyses to probe collagen macromolecular/supramolecular properties to discriminate ex vivo human tissues (normal stroma, benign tumors, and high grade serous tumors) by determination of: i) collagen alpha helical pitch angle, ii) alignment of collagen molecules within fibrils, and iii) collagen helical chirality via SHG circular dichroism (SHG-CD). The largest differences were between normal stroma and benign tumors, consistent with gene expression data showing Col III is up-regulated in the latter. The different tissues also displayed differing collagen alignment within fibrils and SHG-CD responses, consistent with either Col III incorporation or randomization of Col I alignment within benign and high-grade tumors fibrils. These results collectively indicate the fibril assemblies are distinct in all tissues and likely result from synthesis of new collagen rather than remodeling of existing collagen. Importantly, these techniques do not require exogenous labels, and additionally, provide sub-resolution structural information previously obtained through ultrastructural analysis that cannot be performed on intact tissues. We next implemented a novel form of 3D texture analysis and machine learning to delineate the fibrillar morphology observed in SHG images of normal stroma, high risk stroma, benign tumors, and a spectrum of malignant tumors (high grade serous, low grade serous, and endometrioid). We extracted textural features in the 3D image sets to build statistical models of each class and we achieved clinically significant 83-91% classification accuracies for the six classes. Importantly, the 3D analysis significantly outperformed our prior 2D methods. This classification based on collagen morphology will complement conventional classification based on genetic profiles and can serve as an additional biomarker. CONCLUSIONS: Taken together, the combination of the macro/supramolecular probes and the fiber morphology classification will greatly increase our understanding of the TME evolution in human ovarian cancer. These methods and their findings have clinical translational significance in terms of understanding disease etiology, and also by enhancing prognostic and diagnostic capabilities. Citation Format: Kirby R. Campbell, Rajeev Chaudhary, Julia Handel, Bruce Wen, Vikas Singh, Manish Patankar and Paul J. Campagnola. COLLAGEN ALTERATIONS IN HUMAN OVARIAN CANCER PROBED BY SECOND HARMONIC GENERATION (SHG) IMAGING MICROSCOPY [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr AP19.

Purpose To determine the feasibility of using multicomponent-driven equilibrium single-shot observation of T1 and T2 (mcDESPOT) for evaluating the human knee joint at 3.0T and to investigate depth-dependent and regional-dependent variations in multicomponent T2 parameters within articular cartilage. Materials and Methods mcDESPOT was performed on the knee joint of 10 asymptomatic volunteers at 3.0T. Single-component T2 relaxation time (T2single), multicomponent T2 relaxation time for water tightly bound to proteoglycan (T2PG) and bulk water loosely bound to the macromolecular matrix (T2BW), and fraction of water tightly bound to proteoglycan (FPG) were measured in eight cartilage subsections and within the superficial and deep layers of patellar cartilage. Statistical analysis was used to investigate depth-dependent and regional-dependent variations in parameters. Results There was lower (P = 0.001) T2single and T2PG and higher (P < 0.001) FPG in the deep than superficial layer of patellar cartilage. There was higher (P < 0.001) FPG on the weight-bearing surfaces than nonweight-bearing surfaces. There was higher (P < 0.001) T2single, T2PG, and T2BW on the trochlea and posterior medial and lateral femoral condyles than the patella, central medial and lateral femoral condyles, and medial and lateral tibia plateaus. Conclusion Multicomponent T2 parameters of the articular cartilage of the human knee joint can be measured at 3.0T using mcDESPOT and show depth-dependent and regional-dependent variations. J. Magn. Reson. Imaging 2014;39:1191–1197. © 2013 Wiley Periodicals, Inc.

The purpose of this study was to determine the accuracy of knee kinematics and cartilage contact measured by volumetric dynamic MRI. A motor-actuated phantom drove femoral and tibial bone segments through cyclic, 3D motion patterns. Volumetric images were continuously acquired using a 3D radially undersampled cine spoiled gradient echo sequence (SPGR-VIPR). Image data was binned based on position measured via MRI-compatible rotary encoder. High-resolution static images were segmented to create bone models. Model-based tracking was performed by optimally registering the bone models to the volumetric images at each frame of the SPGR-VIPR series. 3D tibiofemoral translations and orientations were reconstructed, and compared to kinematics obtained by tracking fiducial markers. Imaging was repeated on a healthy subject who performed cyclic knee flexion-extension. Cartilage contact for the subject was assessed by measuring the overlap between articular cartilage surfaces. Model-based tracking was able to track tibiofemoral angles and translations with precisions less than 0.8° and 0.5 mm. These precisions resulted in an uncertainty of less than 0.5 mm in cartilage contact location. Dynamic SPGR-VIPR imaging can accurately assess in vivo knee kinematics and cartilage contact during voluntary knee motion performed in a MRI scanner. This technology could facilitate the quantitative investigation of links between joint mechanics and the development of osteoarthritis.

Remodeling of the extracellular matrix in human ovarian cancer can be manifested in increased collagen concentration, changes in alignment within fibrils/fibers and/or up-regulation of different collagen isoforms. We used pixel-based second harmonic generation (SHG) polarization microscopy analyses to probe these molecular changes in human ovarian tissues [normal stroma, benign tumors, and high-grade serous (HGS) tumors] by: (i) determination of the [Formula: see text]-helical pitch angle via the single-axis molecular model, (ii) collagen alignment within fibrils via SHG anisotropy, and (iii) chirality via SHG circular dichroism (SHG-CD). Pixel approaches are required due to the complex structure of the matrix that lacks a high degree of fiber alignment. The largest differences in the helical pitch angle were between normal stroma and benign tumors, consistent with gene expression showing the Col III isoform is up-regulated in the latter. The data were not consistent with up-regulation of Col III in HGS tumors as previous reports have suggested. The different tissues also displayed differing SHG anisotropies and SHG-CD responses, consistent with either Col III incorporation or randomization of Col I alignment within benign and malignant tumors. Additionally, the high-grade tumors displayed higher collagen concentration, where this desmoplasia is consistent with the higher fiber density in these tissues. These results collectively indicate that the fibril assemblies are distinct in all tissues, where these differences likely result from the synthesis of collagen rather than remodeling of existing collagen. Importantly, these analyses are label-free and interrogate subresolution collagen structure on intact tissues, without the need for conventional structural biology tools.

Osteoarthritis is characterized by a decrease in the proteoglycan content and disruption of the highly organized collagen fiber network of articular cartilage. Various quantitative magnetic resonance imaging techniques have been developed for noninvasive assessment of the proteoglycan and collagen components of cartilage. These techniques have been extensively used in clinical practice to detect early cartilage degeneration and in osteoarthritis research studies to monitor disease-related and treatment-related changes in cartilage over time. This article reviews the role of quantitative magnetic resonance imaging in evaluating the composition and ultrastructure of the articular cartilage of the knee joint.

To determine the feasibility of using multicomponent-driven equilibrium single-shot observation of T1 and T2 (mcDESPOT) for evaluating the human knee joint at 3.0T and to investigate depth-dependent and regional-dependent variations in multicomponent T2 parameters within articular cartilage.mcDESPOT was performed on the knee joint of 10 asymptomatic volunteers at 3.0T. Single-component T2 relaxation time (T2single ), multicomponent T2 relaxation time for water tightly bound to proteoglycan (T2PG ) and bulk water loosely bound to the macromolecular matrix (T2BW ), and fraction of water tightly bound to proteoglycan (FPG ) were measured in eight cartilage subsections and within the superficial and deep layers of patellar cartilage. Statistical analysis was used to investigate depth-dependent and regional-dependent variations in parameters.There was lower (P = 0.001) T2single and T2PG and higher (P0.001) FPG in the deep than superficial layer of patellar cartilage. There was higher (P0.001) FPG on the weight-bearing surfaces than nonweight-bearing surfaces. There was higher (P0.001) T2single , T2PG , and T2BW on the trochlea and posterior medial and lateral femoral condyles than the patella, central medial and lateral femoral condyles, and medial and lateral tibia plateaus.Multicomponent T2 parameters of the articular cartilage of the human knee joint can be measured at 3.0T using mcDESPOT and show depth-dependent and regional-dependent variations.