Analysis of 3D pathology samples using weakly supervised AI.

Human tissue, which is inherently three-dimensional (3D), is traditionally examined through standard-of-care histopathology as limited two-dimensional (2D) cross-sections that can insufficiently represent the tissue due to sampling bias. To holistically characterize histomorphology, 3D imaging modalities have been developed, but clinical translation is hampered by complex manual evaluation and lack of computational platforms to distill clinical insights from large, high-resolution datasets. We present TriPath, a deep-learning platform for processing tissue volumes and efficiently predicting clinical outcomes based on 3D morphological features. Recurrence risk-stratification models were trained on prostate cancer specimens imaged with open-top light-sheet microscopy or microcomputed tomography. By comprehensively capturing 3D morphologies, 3D volume-based prognostication achieves superior performance to traditional 2D slice-based approaches, including clinical/histopathological baselines from six certified genitourinary pathologists. Incorporating greater tissue volume improves prognostic performance and mitigates risk prediction variability from sampling bias, further emphasizing the value of capturing larger extents of heterogeneous morphology.

The Hox code responsible for the patterning of the anterior vertebrae in zebrafish.

The vertebral column is a characteristic structure of vertebrates. Genetic studies in mice have shown that Hox-mediated patterning plays a key role in specifying discrete anatomical regions of the vertebral column. Expression pattern analyses in several vertebrate embryos have provided correlative evidence that the anterior boundaries of Hox expression coincide with distinct anatomical vertebrae. However, because functional analyses have been limited to mice, it remains unclear which Hox genes actually function in vertebral patterning in other vertebrates. In this study, various zebrafish Hox mutants were generated for loss-of-function phenotypic analysis to functionally decipher the Hox code responsible for the zebrafish anterior vertebrae between the occipital and thoracic vertebrae. We found that Hox genes in HoxB- and HoxC-related clusters participate in regulating the morphology of the zebrafish anterior vertebrae. In addition, medaka hoxc6a was found to be responsible for anterior vertebral identity, as in zebrafish. Based on phenotypic similarities with Hoxc6 knockout mice, our results suggest that the Hox patterning system, including at least Hoxc6, may have been functionally established in the vertebral patterning of the common ancestor of ray-finned and lobe-finned fishes.

A mouse model of progressive lung fibrosis with cutaneous involvement induced by a combination of oropharyngeal and osmotic minipump bleomycin delivery.

Systemic sclerosis (SSc) with interstitial lung disease (SSc-ILD) lacks curative pharmacological treatments, thus necessitating effective animal models for candidate drug discovery. Existing bleomycin (BLM)-induced SSc-ILD mouse models feature spatially limited pulmonary fibrosis, spontaneously resolving after 28 days. Here, we present an alternative BLM administration approach in female C57BL/6 mice, combining oropharyngeal aspiration (OA) and subcutaneous mini-pump delivery (pump) of BLM to induce a sustained and more persistent fibrosis, while retaining stable skin fibrosis. A dose-finding study was performed with BLM administered as 10 µg (OA) +80 mg/kg (pump) (10 + 80), 10 + 100, and 15 + 100. Forty-two days after OA, micro-computed tomography (micro-CT) imaging and histomorphometric analyses showed that the 10 + 100 and 15 + 100 treatments induced significant alterations in lung micro-CT-derived readouts, Ashcroft score, and more severe fibrosis grades compared with saline controls. In addition, a marked reduction in hypodermal thickness was observed in the 15 + 100 group. A time-course characterization of the BLM 15 + 100 treatment at days 28, 35, and 42, including longitudinal micro-CT imaging, revealed progressing alterations in lung parameters. Lung histology highlighted a sustained fibrosis accompanied by a reduction in hypodermis thickness throughout the explored time-window, with a time-dependent increase in fibrotic biomarkers detected by immunofluorescence analysis. BLM-induced alterations were partly mitigated by Nintedanib treatment. Our optimized BLM delivery approach leads to extensive and persistent lung fibrotic lesions coupled with cutaneous fibrotic alterations: it thus represents a significant advance compared with current preclinical models of BLM-induced SSc-ILD.NEW & NOTEWORTHY This study introduces an innovative approach to enhance the overall performance of the mouse bleomycin (BLM)-induced model for systemic sclerosis with interstitial lung disease (SSc-ILD). By combining oropharyngeal aspiration and subcutaneous mini-pump delivery of BLM, our improved model leads to sustained lung fibrosis and stable skin fibrosis in female C57BL/6 mice. The optimized 15 + 100 treatment results in extensive and persistent lung fibrotic lesions and thus represents a significant improvement over existing preclinical models of BLM-induced SSc-ILD.

LAMA: automated image analysis for the developmental phenotyping of mouse embryos.

Advanced 3D imaging modalities, such as micro-computed tomography (micro-CT), have been incorporated into the high-throughput embryo pipeline of the International Mouse Phenotyping Consortium (IMPC). This project generates large volumes of raw data that cannot be immediately exploited without significant resources of personnel and expertise. Thus, rapid automated annotation is crucial to ensure that 3D imaging data can be integrated with other multi-dimensional phenotyping data. We present an automated computational mouse embryo phenotyping pipeline that harnesses the large amount of wild-type control data available in the IMPC embryo pipeline in order to address issues of low mutant sample number as well as incomplete penetrance and variable expressivity. We also investigate the effect of developmental substage on automated phenotyping results. Designed primarily for developmental biologists, our software performs image pre-processing, registration, statistical analysis and segmentation of embryo images. We also present a novel anatomical E14.5 embryo atlas average and, using it with LAMA, show that we can uncover known and novel dysmorphology from two IMPC knockout lines.

Defective mesothelium and limited physical space are drivers of dysregulated lung development in a genetic model of congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) is a developmental disorder associated with diaphragm defects and lung hypoplasia. The etiology of CDH is complex and its clinical presentation is variable. We investigated the role of the pulmonary mesothelium in dysregulated lung growth noted in the Wt1 knockout mouse model of CDH. Loss of WT1 leads to intrafetal effusions, altered lung growth, and branching defects prior to normal closure of the diaphragm. We found significant differences in key genes; however, when Wt1 null lungs were cultured ex vivo, growth and branching were indistinguishable from wild-type littermates. Micro-CT imaging of embryos in situ within the uterus revealed a near absence of space in the dorsal chest cavity, but no difference in total chest cavity volume in Wt1 null embryos, indicating a redistribution of pleural space. The altered space and normal ex vivo growth suggest that physical constraints are contributing to the CDH lung phenotype observed in this mouse model. These studies emphasize the importance of examining the mesothelium and chest cavity as a whole, rather than focusing on single organs in isolation to understand early CDH etiology.

tomoCAM: fast model-based iterative reconstruction via GPU acceleration and non-uniform fast Fourier transforms.

X-ray-based computed tomography is a well established technique for determining the three-dimensional structure of an object from its two-dimensional projections. In the past few decades, there have been significant advancements in the brightness and detector technology of tomography instruments at synchrotron sources. These advancements have led to the emergence of new observations and discoveries, with improved capabilities such as faster frame rates, larger fields of view, higher resolution and higher dimensionality. These advancements have enabled the material science community to expand the scope of tomographic measurements towards increasingly in situ and in operando measurements. In these new experiments, samples can be rapidly evolving, have complex geometries and restrictions on the field of view, limiting the number of projections that can be collected. In such cases, standard filtered back-projection often results in poor quality reconstructions. Iterative reconstruction algorithms, such as model-based iterative reconstructions (MBIR), have demonstrated considerable success in producing high-quality reconstructions under such restrictions, but typically require high-performance computing resources with hundreds of compute nodes to solve the problem in a reasonable time. Here, tomoCAM, is introduced, a new GPU-accelerated implementation of model-based iterative reconstruction that leverages non-uniform fast Fourier transforms to efficiently compute Radon and back-projection operators and asynchronous memory transfers to maximize the throughput to the GPU memory. The resulting code is significantly faster than traditional MBIR codes and delivers the reconstructive improvement offered by MBIR with affordable computing time and resources. tomoCAM has a Python front-end, allowing access from Jupyter-based frameworks, providing straightforward integration into existing workflows at synchrotron facilities.

The hidden diversity of vascular patterns in flower heads.

Vascular systems are intimately related to the shape and spatial arrangement of the plant organs they support. We investigate the largely unexplored association between spiral phyllotaxis and the vascular system in Asteraceae flower heads. We imaged heads of eight species using synchrotron-based X-ray micro-computed tomography and applied original virtual reality and haptic software to explore head vasculature in three dimensions. We then constructed a computational model to infer a plausible patterning mechanism. The vascular system in the head of the model plant Gerbera hybrida is qualitatively different from those of Bellis perennis and Helianthus annuus, characterized previously. Cirsium vulgare, Craspedia globosa, Echinacea purpurea, Echinops bannaticus, and Tanacetum vulgare represent variants of the Bellis and Helianthus systems. In each species, the layout of the main strands is stereotypical, but details vary. The observed vascular patterns can be generated by a common computational model with different parameter values. In spite of the observed differences of vascular systems in heads, they may be produced by a conserved mechanism. The diversity and irregularities of vasculature stand in contrast with the relative uniformity and regularity of phyllotactic patterns, confirming that phyllotaxis in heads is not driven by the vasculature.

Micro-CT, Mechanical, and Histological Examination of the Effect of Local Adjuvants on Porcine Cortical Bone Following Intralesional Curettage of Bone Tumors.

BACKGROUND AND OBJECTIVES: Curettage is the removal of a tumor from the bone while preserving the surrounding healthy cortical bone, and is associated with higher rates of local recurrence. To lower these rates, curettage should be combined with local adjuvants, although their use is associated with damage to nearby healthy bone. OBJECTIVE: The purpose of this analysis is to determine the effect of local adjuvants on cortical porcine bone by using micro-computed tomography (micro-CT) along with histological and mechanical examination. METHODS: Local adjuvants were applied to porcine specimens under defined conditions. To assess changes in bone mineral density (BMD), a micro-CT scan was used. The pixel gray values of the volume of interest (VOI) were evaluated per specimen and converted to BMD values. The Vickers hardness test was employed to assess bone hardness (HV). The depth of necrosis was measured histologically using hematoxylin and eosin-stained tissue sections. RESULTS: A noticeable change in BMD was observed on the argon beam coagulation (ABC) sample. Comparable hardness values were measured on samples following electrocautery and ABC, and lowering of bone hardness was obtained in the case of liquid nitrogen. Extensive induced depth of necrosis was registered in the specimen treated with liquid nitrogen. CONCLUSION: This study determined the effect of local adjuvants on cortical bone by using micro-CT along with histological and mechanical examination. Phenolization and liquid nitrogen application caused a decrease in bone hardness. The bone density was affected in the range of single-digit percentage values. Liquid nitrogen induced extensive depth of necrosis with a wide variance of values.

Phenotyping xylem connections in grafted plants using X-ray micro-computed tomography.

Plants are able to naturally graft or inosculate their trunks, branches and roots together, this mechanism is used by humans to graft together different genotypes for a range of purposes. Grafts are considered successful if functional vascular connections between the two genotypes occur. Various techniques can evaluate xylem connections across the graft interface. However, these methods are generally unable to assess the heterogeneity and three-dimensional (3D) structure of xylem vessel connections. Here we present the use of X-ray micro-computed tomography to characterize the 3D morphology of grafts of grapevine. We show that xylem vessels form between the two plants of natural root and human-made stem grafts. The main novelty of this methodology is that we were able to visualize the 3D network of functional xylem vessels connecting the scion and rootstock in human-made stem grafts thanks to the addition of a contrast agent to the roots and improved image analysis pipelines. In addition, we reveal the presence of extensive diagonal xylem connections between the main axial xylem vessels in 2-year old grapevine stems. In conclusion, we present a method that has the potential to provide new insights into the structure and function of xylem vessels in large tissue samples.

Comparative skeletal anatomy of salt marsh and western harvest mice in relation to locomotor ecology.

The salt marsh harvest mouse (Reithrodontomys raviventris) is an endangered species, endemic to the San Francisco Bay Estuary, that co-occurs with the more broadly distributed species, the western harvest mouse (Reithrodontomys megalotis). Despite their considerable external morphological similarities, the northern subspecies of salt marsh harvest mice have relatively longer and thicker tails than do western harvest mice, which may be related to their abilities to climb emergent marsh vegetation to avoid tidal inundation. We used micro-CT to compare post-cranial skeletal anatomy between the salt marsh and western harvest mouse, to examine whether the salt marsh harvest mouse's restriction to brackish marshes is associated with skeletal adaptations for scansorial locomotion. We found that salt marsh harvest mice exhibited a deeper 3rd caudal vertebra, a more caudally located longest tail vertebra, craniocaudally longer tail vertebrae, and a longer digit III proximal phalanx than western harvest mice. These phalangeal and vertebral characteristics are known to decrease body rotations during climbing, increase contact with substrates, and decrease fall susceptibility in arboreal mammals, suggesting that the salt marsh harvest mouse may be morphologically specialized for scansorial locomotion, adaptive for its dynamic wetland environment.

Metabolic and Skeletal Characterization of the KK/Ay Mouse Model-A Polygenic Mutation Model of Obese Type 2 Diabetes.

Type 2 diabetes (T2D) increases fracture incidence and fracture-related mortality rates (KK.Cg-Ay/J. The Jackson Laboratory; Available from: https://www.jax.org/strain/002468 ). While numerous mouse models for T2D exist, few effectively stimulate persistent hyperglycemia in both sexes, and even fewer are suitable for bone studies. Commonly used models like db/db and ob/ob have altered leptin pathways, confounding bone-related findings since leptin regulates bone properties (Fajardo et al. in Journal of Bone and Mineral Research 29(5): 1025-1040, 2014). The Yellow Kuo Kondo (KK/Ay) mouse, a polygenic mutation model of T2D, is able to produce a consistent diabetic state in both sexes and addresses the lack of a suitable model of T2D for bone studies. The diabetic state of KK/Ay stems from a mutation in the agouti gene, responsible for coat color in mice. This mutation induces ectopic gene expression across various tissue types, resulting in diabetic mice with yellow fur coats (Moussa and Claycombe in Obesity Research 7(5): 506-514, 1999). Male and female KK/Ay mice exhibited persistent hyperglycemia, defining them as diabetic with blood glucose (BG) levels consistently exceeding 300 mg/dL. Notably, male control mice in this study were also diabetic, presenting a significant limitation. Nevertheless, male and female KK/Ay mice showed significantly elevated BG levels, HbA1c, and serum insulin concentration when compared to the non-diabetic female control mice. Early stages of T2D are characterized by hyperglycemia and hyperinsulinemia resulting from cellular insulin resistance, whereas later stages may feature hypoinsulinemia due to ß-cell apoptosis (Banday et al. Avicenna Journal of Medicine 10(04): 174-188, 2020 and Klein et al. Cell Metabolism 34(1): 11-20, 2022). The observed hyperglycemia, hyperinsulinemia, and the absence of differences in ß-cell mass suggest that KK/Ay mice in this study are modeling the earlier stages of T2D. While compromised bone microarchitecture was observed in this study, older KK/Ay mice, representing more advanced stages of T2D, might exhibit more pronounced skeletal manifestations. Compared to the control group, the femora of KK/Ay mice had higher cortical area and cortical thickness, and improved trabecular properties which would typically be indicative of greater bone strength. However, KK/Ay mice displayed lower cortical tissue mineral density in both sexes and increased cortical porosity in females. Fracture instability toughness of the femora was lower in KK/Ay mice overall compared to controls. These findings indicate that decreased mechanical integrity noted in the femora of KK/Ay mice was likely due to overall bone quality being compromised.

Trabecular bone volume fraction in Holocene and Late Pleistocene humans.

Research suggests that recent modern humans have gracile skeletons in having low trabecular bone volume fraction (BV/TV) and that gracilization of the skeleton occurred in the last 10,000 years. This has been attributed to a reduction in physical activity in the Holocene. However, there has been no thorough sampling of BV/TV in Pleistocene humans due to limited access to high resolution images of fossil specimens. Therefore, our study investigates the gracilization of BV/TV in Late Pleistocene humans and recent (Holocene) modern humans to improve our understanding of the emergence of gracility. We used microcomputed tomography to measure BV/TV in the femora, humeri and metacarpals of a sample of Late Pleistocene humans from Dolní Vestonice (Czech Republic, ∼26 ka, n = 6) and Ohalo II (Israel, ∼19 ka, n = 1), and a sample of recent humans including farming groups (n = 39) and hunter-gatherers (n = 6). We predicted that 1) Late Pleistocene humans would exhibit greater femoral and humeral head BV/TV compared with recent humans and 2) among recent humans, metacarpal head BV/TV would be greater in hunter-gatherers compared with farmers. Late Pleistocene humans had higher BV/TV compared with recent humans in both the femur and humerus, supporting our first prediction, and consistent with previous findings that Late Pleistocene humans are robust as compared to recent humans. However, among recent humans, there was no significant difference in BV/TV in the metacarpals between the two subsistence groups. The results highlight the similarity in BV/TV in the hand of two human groups from different geographic locales and subsistence patterns and raise questions about assumptions of activity levels in archaeological populations and their relationships to trabecular BV/TV.

Effect of EDTA with porous balloon on calcified lesion: An atherosclerotic cadaver study.

BACKGROUND: Ethylene diamine tetra-acetic acid (EDTA) is a chelating agent used to dissolve calcium deposits but evidence in decalcifying atherosclerotic lesions is limited. AIMS: We assessed the feasibility and efficacy of EDTA delivered via porous balloon to target calcified lesions in cadaveric below-the-knee (BTK) arteries. METHODS: Using porcine carotid arteries, EDTA concentration was measured in the arterial wall and outside the artery at the 0-, 0.5-, 4-, and 24-h circulation after the injection through a porous balloon. In cadaver BTK samples, the proximal and distal anterior tibial artery (ATA) and distal posterior tibial artery (PTA) were studied. EDTA-2Na/H2O or EDTA-3Na/H2O were administrated using a porous balloon, then circulated for 6 h for EDTA-3Na/H2O and 24 h for EDTA-2Na/H2O and EDTA-3Na/H2O. Micro-CT imaging of the artery segments before and after the circulation and cross-sectional analyses were performed to evaluate calcium burden. RESULTS: In the porcine carotid study, EDTA was delivered through a porous balloon present in the arterial wall and was retained there for 24 h. In BTK arteries, cross-sectional analyses of micro-CT revealed a significant decrease in the calcium area in the distal ATA segment under 24-h circulation with EDTA-2Na/H2O and in the distal ATA segment under 24-h circulation with EDTA-3Na/H2O. The proximal ATA segment under 6-h circulation with EDTA-3Na/H2O showed no significant change in any parameters of calcium CONCLUSION: EDTA-3Na/H2O or EDTA-2Na/H2O with longer circulation times resulted in greater calcium reduction in atherosclerotic lesion. EDTA may have a potential therapeutic option for the treatment of atherosclerotic calcified lesions.

Scaling of buccal mass growth and muscle activation determine the duration of feeding behaviours in the marine mollusc Aplysia californica.

The mechanical forces experienced during movement and the time constants of muscle activation are important determinants of the durations of behaviours, which may both be affected by size-dependent scaling. The mechanics of slow movements in small animals are dominated by elastic forces and are thus quasistatic (i.e. always near mechanical equilibrium). Muscular forces producing movement and elastic forces resisting movement should scale identically (proportional to mass2/3), leaving the scaling of the time constant of muscle activation to play a critical role in determining behavioural duration. We tested this hypothesis by measuring the duration of feeding behaviours in the marine mollusc Aplysia californica whose body sizes spanned three orders of magnitude. The duration of muscle activation was determined by measuring the time it took for muscles to produce maximum force as A. californica attempted to feed on tethered inedible seaweed, which provided an in vivo approximation of an isometric contraction. The timing of muscle activation scaled with mass0.3. The total duration of biting behaviours scaled identically, with mass0.3, indicating a lack of additional mechanical effects. The duration of swallowing behaviour, however, exhibited a shallower scaling of mass0.17. We suggest that this was due to the allometric growth of the anterior retractor muscle during development, as measured by micro-computed tomography (micro-CT) scans of buccal masses. Consequently, larger A. californica did not need to activate their muscles as fully to produce equivalent forces. These results indicate that muscle activation may be an important determinant of the scaling of behavioural durations in quasistatic systems.

Convergently evolved placental villi show multiscale structural adaptations to differential placental invasiveness.

Despite having a single evolutionary origin and conserved function, the mammalian placenta exhibits radical structural diversity. The evolutionary drivers and functional consequences of placental structural diversity are poorly understood. Humans and equids both display treelike placental villi, however these villi evolved independently and exhibit starkly different levels of invasiveness into maternal tissue (i.e. the number of maternal tissue layers between placental tissue and maternal blood). The villi in these species therefore serve as a compelling evolutionary case study to explore whether placentas have developed structural adaptations to respond to the challenge of reduced nutrient availability in less invasive placentas. Here, we use three-dimensional X-ray microfocus computed tomography and electron microscopy to quantitatively evaluate key structures involved in exchange in human and equid placental villi. We find that equid villi have a higher surface area to volume ratio and deeper trophoblastic vessel indentation than human villi. Using illustrative computational models, we propose that these structural adaptations have evolved in equids to boost nutrient transfer to compensate for reduced invasiveness into maternal tissue. We discuss these findings in relation to the 'maternal-fetal conflict hypothesis' of placental evolution.

Plastic Fruit Stickers in Industrial Composting─Surface and Structural Alterations Revealed by Electron Microscopy and Computed Tomography.

Often large quantities of plastics are found in compost, with price look-up stickers being a major but little-explored component in the contamination path. Stickers glued to fruit or vegetable peels usually remain attached to the organic material despite sorting processes in the composting plant. Here, we investigated the effects of industrial composting on the structural alterations of these stickers. Commercial polypropylene (PP) stickers on banana peels were added to a typical organic material mixture for processing in an industrial composting plant and successfully resampled after a prerotting (11 days) and main rotting step (25 days). Afterward, both composted and original stickers were analyzed for surface and structural changes via scanning electron microscopy, Fourier-transform infrared spectroscopy, and micro- and nano-X-ray computed tomography (CT) combined with deep learning approaches. The composting resulted in substantial surface changes and degradation in the form of microbial colonization, deformation, and occurrence of cracks in all stickers. Their pore volumes increased from 16.7% in the original sticker to 26.3% at the end of the compost process. In a similar way, the carbonyl index of the stickers increased. Micro-CT images additionally revealed structural changes in the form of large adhesions that penetrated the surface of the sticker. These changes were accompanied by delamination after 25 days of composting, thus overall hinting at the degradation of the stickers and the subsequent formation of smaller microplastic pieces.

Exploring Carbonate Rock Dissolution Dynamics and the Influence of Rock Mineralogy in CO2 Injection.

Understanding geochemical dissolution in porous materials is crucial, especially in applications such as geological CO2 storage. Accurate estimation of reaction rates enhances predictive modeling in geochemical-flow simulations. Fractured porous media, with distinct transport time scales in fractures and the matrix, raise questions about fracture-matrix interface dissolution rates compared to bulk dissolution rate and the scale-dependency of reaction rate averaging. Our investigation delves into these factors, studying the impact of flow rate and mineralogy on interface dissolution patterns. By injecting carbonated water into carbonate rock samples containing a central channel (mimicking fracture hydrodynamics), our study utilized µCT X-ray imaging at 3.3 µm spatial resolution to estimate the reaction rate and capture the change in pore morphology. Results revealed dissolution rates significantly lower (up to 4 orders of magnitude) than batch experiments. Flow rate notably influenced fracture profiles, causing uneven enlargement at low rates and uniform widening at higher ones. Ankerite presence led to a dissolution-altered layer on the fracture surface, showing high permeability and porosity without greatly affecting the dissolution rate, unlike clay-rich carbonates. This research sheds light on controlling factors influencing dissolution in subsurface environments, critical for accurate modeling in diverse applications.

Preclinical evaluation of a new synthetic carbonate apatite bone substitute on periodontal regeneration in intrabony defects.

OBJECTIVE: To evaluate the potential of a novel synthetic carbonate apatite bone substitute (CO3 Ap-BS) on periodontal regeneration. BACKGROUND: The use of various synthetic bone substitutes as a monotherapy for periodontal regeneration mainly results in a reparative healing pattern. Since xenografts or allografts are not always accepted by patients for various reasons, a synthetic alternative would be desirable. METHODS: Acute-type 3-wall intrabony defects were surgically created in 4 female beagle dogs. Defects were randomly allocated and filled with CO3 Ap-BS (test) and deproteinized bovine bone mineral (DBBM) or left empty (control). After 8 weeks, the retrieved specimens were scanned by micro-CT, and the percentages of new bone, bone substitute, and soft tissues were evaluated. Thereafter, the tissues were histologically and histometrically analyzed. RESULTS: Healing was uneventful in all animals, and defects were present without any signs of adverse events. Formation of periodontal ligament and cementum occurred to varying extent in all groups without statistically significant differences between the groups. Residues of both bone substitutes were still present and showed integration into new bone. Histometry and micro-CT revealed that the total mineralized area or volume was higher with the use of CO3 Ap-BS compared to control (66.06 ± 9.34%, 36.11 ± 6.40%; p = .014, or 69.74 ± 2.95%, 42.68 ± 8.68%; p = .014). The percentage of bone substitute surface covered by new bone was higher for CO3 Ap-BS (47.22 ± 3.96%) than for DBBM (16.69 ± 5.66, p = .114). CONCLUSIONS: CO3 Ap-BS and DBBM demonstrated similar effects on periodontal regeneration. However, away from the root surface, more new bone, total mineralized area/volume, and higher osteoconductivity were observed for the CO3 Ap-BS group compared to the DBBM group. These findings point to the potential of CO3 Ap-BS for periodontal and bone regeneration.

High resolution imaging of human development: shedding light on contrast agents.

BACKGROUND: Visualizing (micro)vascular structures remains challenging for researchers and clinicians due to limitations in traditional radiological imaging methods. Exploring the role of vascular development in craniofacial malformations in experimental settings can enhance understanding of these processes, with the effectiveness of high-resolution imaging techniques being crucial for successful research in this field. Micro-CT imaging offers 3D microstructural insights, but requires contrast-enhancing staining agents (CESAs) for visualizing (micro)-vascular tissues, known as contrast-enhanced micro-CT (CECT). As effective contrast agents are crucial for optimal visualization, this review focuses on comparative studies investigating such agents for micro-vascular tissue imaging using micro-CT. Furthermore, we demonstrate the utilization of B-Lugol solution as a promising contrast agent for acquiring high-quality micro-CT images of (micro)vascular structures in human embryonic samples. METHOD: This scoping review followed Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols. PubMed database provided relevant articles, screened initially by title and abstract. Inclusion and exclusion criteria defined outcomes of interest. RESULTS: From an initial search, 273 records were identified, narrowed down to 9 articles after applying our criteria. Additionally, two articles were added through citation searching. This, a total of 11 articles were incorporated in this study. CONCLUSION: This micro-CT contrast agent review underscores the need for tailored choices based on research goals. Both Barium sulfate and Iodine-based agents showing excellent results, providing high resolution (micro) vascular content, especially in ex-vivo specimens. However, careful consideration of protocols and tissue characteristics remains imperative for optimizing the effectiveness of micro-CT imaging for the study of cranio-facial vascular development.

Histological Observation of Helmet Development in the Treehopper Poppea capricornis (Insecta: Hemiptera: Membracidae).

The treehoppers (Hemiptera, Membracidae) are known for possessing a large three-dimensional structure called a helmet. Although some ecological functions of the helmet have already been elucidated, the developmental mechanisms underlying the complex and diverse morphology of the helmet are still largely unknown. The process of helmet formation was first described in Antianthe expansa, which possesses a simple roof-shaped helmet. However, the developmental process in species with more complex helmet morphologies remains largely unexplored. Hence, in this study, we used Poppea capricornis, which possesses a more complex helmet structure than A. expansa, to investigate the helmet development using paraffin sections, micro-CT, and scanning electronic microscopy. Our focus was on the overall helmet developmental process common to both species and formation of structures unique to Poppea and its comparison to Antianthe. As a result, we discovered that miniature structures were also formed in Poppea, similar to Antianthe, during the helmet formation. Common structures that were shared between the two species were discernible at this stage. Additionally, we observed that suprahumeral horns and posterior horns, two morphological traits specific to the Poppea helmet that are apparently similar anatomically, are formed through two distinctly different developmental mechanisms. The suprahumeral horns appeared to be formed by utilizing the nymphal suprahumeral bud as a mold, while we could not detect any nymphal structures potentially used for a mold in the posterior horns formation. Our findings suggest that the helmet formation mechanisms of Antianthe and Poppea employ a common mechanism but form species-specific structures by multiple mechanisms.