Changes in bone structure and metabolism during simulated weightlessness: Endocrine and dietary factors

The role of vitamin D, PTH and corticosterone in the skeletal alterations induced by simulated weightlessness was examined. The first objective was to determine if changes in the serum concentrations of Ca, P sub i, osteocalcin, 25-OH-D, 24,25(OH)2D or 1,25(OH)2D also occur following acute skeletal unloading. Animals were either suspended or pair fed for 2, 5, 7, 10, 12 and 15 days and the serum concentrations of Ca, P sub i, osteocalcin and the vitamin D metabolites measured. Bone histology was examined at day 5 after suspension. Acute skeletal unloading produced a transient hypercalcemia, a significant fall in serum osteocalcin and serum 1,25(OH)2D, a slight rise in serum 24,25(OH)2D, but did not affect the serum concentrations of P sub i or 25-OH-D. At the nadir in serum 1,25(OH)2D serum osteocalcin was reduced by 22%, osteoblast surface by 32% and longitudinal bone growth by 21%

The role of 1,25-dihydroxyvitamin D in the inhibition of bone formation induced by skeletal unloading

Skeletal unloading results in osteopenia. To examine the involvement of vitamin D in this process, the rear limbs of growing rats were unloaded and alterations in bone calcium and bone histology were related to changes in serum calcium (Ca), inorganic phosphorus (P sub i), 25-hydroxyvitamin D (25-OH-D), 24,25-dihydroxyvitamin D (24,25(OH)2D and 1,25-dihydroxyvitamin D (1,25(OH)2D. Acute skeletal unloading induced a transitory inhibition of Ca accumulation in unloaded bones. This was accompanied by a transitory rise in serum Ca, a 21% decrease in longitudinal bone growth (P 0.01), a 32% decrease in bone surface lined with osteoblasts (P .05), no change in bone surface lined with osteoclasts and a decrease in circulating (1,25(OH)2D. No significant changes in the serum concentrations of P sub i, 25-OH-D or 24,25(OH)2D were observed. After 2 weeks of unloading, bone Ca stabilized at approximately 70% of control and serum Ca and 1,25(OH)2D returned to control values. Maintenance of a constant serum 1,25(OH)2D concentration by chronic infusion of 1,25(OH)2D (Alza osmotic minipump) throughout the study period did not prevent the bone changes induced by acute unloading. These results suggest that acute skeletal unloading in the growing rat produces a transitory inhibition of bone formation which in turn produces a transitory hypercalcemia

Role of Corticosteroids in Bone Loss During Space Flight

The primary objective of this research project is to test the hypothesis that corticosteroids contribute to the adverse skeletal effects of space flight. To achieve this objective, serum corticosteroids, which are known to increase during space flight, must be maintained at normal physiologic levels in flight rats by a combination of adrenalectomy and corticosteroid supplementation via implanted hormone pellets. Bone analyses in these animals will then be compared to those of intact flight rats that, based on past experience, will undergo corticosteroid excess and bone loss during space flight. The results will reveal whether maintaining serum corticosteroids at physiologic levels in flight rats affects the skeletal abnormalities that normally develop during space flight. A positive response to this question would indicate that the bone loss and decreased bone formation associated with space flight are mediated, at least in part, by corticosteroid excess

Etiology of the Broad Avoidant Restrictive Food Intake Disorder Phenotype in Swedish Twins Aged 6 to 12 Years

IMPORTANCE: Avoidant restrictive food intake disorder (ARFID) is characterized by an extremely limited range and/or amount of food eaten, resulting in the persistent failure to meet nutritional and/or energy needs. Its etiology is poorly understood, and knowledge of genetic and environmental contributions to ARFID is needed to guide future research. OBJECTIVE: To estimate the extent to which genetic and environmental factors contribute to the liability to the broad ARFID phenotype. DESING, SETTING AND PARTICIPANTS: This nationwide Swedish twin study includes 16 951 twin pairs born between 1992 and 2010 whose parents participated in the Child and Adolescent Twin Study in Sweden (CATSS) at twin age 9 or 12 years. CATSS was linked to the National Patient Register (NPR) and the Prescribed Drug Register (PDR). Data were collected from July 2004 to April 2020, and data were analyzed from October 2021 to October 2022. MAIN OUTCOMES AND MEASURES: This nationwide Swedish twin study includes 16 951 twin pairs born between 1992 and 2010 whose parents participated in the Child and Adolescent Twin Study in Sweden (CATSS) at twin age 9 or 12 years. CATSS was linked to the National Patient Register (NPR) and the Prescribed Drug Register (PDR). Data were collected from July 2004 to April 2020, and data were analyzed from October 2021 to October 2022. RESULTS: Of 33 902 included children, 17 151 (50.6%) were male. A total of 682 children (2.0%) with the ARFID phenotype were identified. The heritability of ARFID was 0.79 (95% CI, 0.70-0.85), with significant contributions from nonshared environmental factors (0.21; 95% CI, 0.15-0.30). Heritability was very similar when excluding children with autism (0.77; 95% CI, 0.67-0.84) or medical illnesses that could account for the eating disturbance (0.79; 95% CI, 0.70-0.86). CONCLUSIONS AND RELEVANCE: Prevalence and sex distribution of the broad ARFID phenotype were similar to previous studies, supporting the use of existing epidemiological data to identify children with ARFID. This study of the estimated genetic and environmental etiology of ARFID suggests that ARFID is highly heritable, encouraging future twin and molecular genetic studies

Long-Term Mortality Monitoring of Captive Sand Gazelles (Gazella Marica): Assessment and Recommendation

The major objective of captive breeding programs for threatened wildlife species is the production of animals for reintroduction and to maintain self-sustaining populations in captivity. One strategy to improve reintroduction success as a conservation tool, is to produce enough animals that have good prospects for survival in the wild. It is therefore imperative to increase the number of potential recruits by reducing mortalities within the captive population. This goal can be best achieved by implementing a good animal health and welfare management. Causes of mortality in captive sand gazelles (Gazella marica) held at King Khalid Wildlife Research Center (KKWRC) in Saudi Arabia were monitored from 1988 to 2012. For this purpose, the pathology and necropsy records of 1,938 mortalities recorded at KKWRC were reviewed and summarized. The largest number of deaths were due to trauma (n = 744, 36.1%), whereby, 291 cases were self-inflicted (15.0%), 210 were caused by predators (10.8%), and 243 cases could be attributed to mate aggression (12.5%). Malnutrition (n = 108, 5.6%) and birth-related causes, such as maternal neglect (n = 165, 8.5%), dystocia (n = 44, 2.3%) and stillbirth (n = 95, 4.9%) accounted for another 21.3% of all mortalities. Among the infectious diseases, respiratory infection was the major cause of mortality, accounting for 159 cases (8.2%) of recorded deaths. Respiratory infections were most prevalent during spring (March - May) suggesting seasonal or climatic effects. Other clinical causes of death included gastro-intestinal diseases (n = 31, 1.6%) and general infections (n = 146, 7.5%), such as that with Pasteurella multocida. Euthanasia due to disease management (n=74, 3.8%) such as Brucella melitensis and Mycobacterium bovis eradication were also important causes of mortality. The study discussed the significance of these findings to improve the captive management of sand gazelles in captivity and reports in detail on the first Brucella melitensis and Pasteurella multicida cases in this threatened desert ungulate

Hematopoietic stem cell gene therapy for brain metastases using myeloid cell-specific gene promoters

Background: Brain metastases (BrM) develop in 20-40% of cancer patients and represent an unmet clinical need. Limited access of drugs into the brain due to the blood-brain barrier is at least partially responsible for therapeutic failure, necessitating improved drug delivery systems. Methods: Green fluorescent protein (GFP)-transduced murine and non-transduced human hematopoietic stem cells (HSCs) were administered into mice (n = 10 and 3). The HSC progeny in mouse BrM and in patient-derived BrM tissue (n = 6) was characterized by flow cytometry and immunofluorescence. Promoters driving gene expression, specifically within the BrM-infiltrating HSC progeny, were identified through differential gene expression analysis and subsequent validation of a series of promoter-GFP-reporter constructs in mice (n = 5). One of the promoters was used to deliver TNF-related apoptosis-inducing ligand (TRAIL) to BrM in mice (n = 17/21 for TRAIL versus control group). Results: HSC progeny (consisting mostly of macrophages) efficiently homed to macrometastases (37.6% [SD = 7.2%] of all infiltrating cells for murine HSC progeny; 27.9% [SD = 4.9%] of infiltrating CD45+ hematopoietic cells for human HSC progeny) and micrometastases in mice (19.3-53.3% of all macrophages for murine HSCs). Macrophages were also abundant in patient-derived BrM tissue (8.8%, SD = 7.8%). Collectively, this provided a rationale to optimize the delivery of gene therapy to BrM within myeloid cells. MMP14 promoter emerged as the strongest promoter construct capable of limiting gene expression to BrM-infiltrating myeloid cells in mice TRAIL delivered under MMP14 promoter statistically significantly prolonged survival in mice (19.0 [SD = 3.4] versus 15.0 [SD = 2.0] days for TRAIL versus control group; two-sided p = 0.006), demonstrating therapeutic and translational potential of our approach. Conclusions: Our study establishes HSC gene therapy using a myeloid cell-specific promoter as a new strategy to target BrM. This approach, with strong translational value, has potential to overcome the blood-brain barrier, target micrometastases, and control multifocal lesions

Content-Aware Unsupervised Deep Homography Estimation

Homography estimation is a basic image alignment method in many applications. It is usually conducted by extracting and matching sparse feature points, which are error-prone in low-light and low-texture images. On the other hand, previous deep homography approaches use either synthetic images for supervised learning or aerial images for unsupervised learning, both ignoring the importance of handling depth disparities and moving objects in real world applications. To overcome these problems, in this work we propose an unsupervised deep homography method with a new architecture design. In the spirit of the RANSAC procedure in traditional methods, we specifically learn an outlier mask to only select reliable regions for homography estimation. We calculate loss with respect to our learned deep features instead of directly comparing image content as did previously. To achieve the unsupervised training, we also formulate a novel triplet loss customized for our network. We verify our method by conducting comprehensive comparisons on a new dataset that covers a wide range of scenes with varying degrees of difficulties for the task. Experimental results reveal that our method outperforms the state-of-the-art including deep solutions and feature-based solutions.Comment: Accepted by ECCV 2020 (Oral, Top 2%, 3 over 3 Strong Accepts). Jirong Zhang and Chuan Wang are joint first authors, and Shuaicheng Liu is the corresponding autho