534 research outputs found
Classification of Rangeland Vegetation and Modeling of Vegetation Patterns at the Jabal al Akhdar Moutain, Northern Oman
Morphology of Mouse Anterior Cruciate Ligament-Complex Changes Following Exercise During Pubertal Growth
Postnatal development and the physiological loading response of the anterior cruciate ligament (ACL) complex (ACL proper, entheses, and bony morphology) is not well understood. We tested whether the ACL-complex of two inbred mouse strains that collectively encompass the musculoskeletal variation observed in humans would demonstrate significant morphological differences following voluntary cage-wheel running during puberty compared with normal cage activity controls. Female A/J and C57BL/6J (B6) 6-week-old mice were provided unrestricted access to a standard cage-wheel for 4 weeks. A/J-exercise mice showed a 6.3% narrower ACL (p-=-0.64), and a 20.1% more stenotic femoral notch (p-<-0.01) while B6-exercise mice showed a 12.3% wider ACL (p-=-0.10), compared with their respective controls. Additionally, A/J-exercise mice showed a 5.3% less steep posterior medial tibial slope (p-=-0.07) and an 8.8% less steep posterior lateral tibial slope (p-=-0.07), while B6-exercise mice showed a 9.8% more steep posterior medial tibial slope (p-<-0.01) than their respective controls. A/J-exercise mice also showed more reinforcement of the ACL tibial enthesis with a 20.4% larger area (p-<-0.01) of calcified fibrocartilage distributed at a 29.2% greater depth (p-=-0.02) within the tibial enthesis, compared with their controls. These outcomes suggest exercise during puberty significantly influences ACL-complex morphology and that inherent morphological differences between these mice, as observed in their less active genetically similar control groups, resulted in a divergent phenotypic outcome between mouse strains. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1910-1919, 2019Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151297/1/jor24328.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151297/2/jor24328_am.pd
Gene Expression Profile and Acute Gene Expression Response to Sclerostin Inhibition in Osteogenesis Imperfecta Bone
Sclerostin antibody (SclAb) therapy has been suggested as a novel therapeutic approach toward addressing the fragility phenotypic of osteogenesis imperfecta (OI). Observations of cellular and transcriptional responses to SclAb in OI have been limited to mouse models of the disorder, leaving a paucity of data on the human OI osteoblastic cellular response to the treatment. Here, we explore factors associated with response to SclAb therapy in vitro and in a novel xenograft model using OI bone tissue derived from pediatric patients. Bone isolates (approximately 2 mm3) from OI patients (OI type III, type III/IV, and type IV, n = 7; non‐OI control, n = 5) were collected to media, randomly assigned to an untreated (UN), low‐dose SclAb (TRL, 2.5 μg/mL), or high‐dose SclAb (TRH, 25 μg/mL) group, and maintained in vitro at 37°C. Treatment occurred on days 2 and 4 and was removed on day 5 for TaqMan qPCR analysis of genes related to the Wnt pathway. A subset of bone was implanted s.c. into an athymic mouse, representing our xenograft model, and treated (25 mg/kg s.c. 2×/week for 2/4 weeks). Implanted OI bone was evaluated using μCT and histomorphometry. Expression of Wnt/Wnt‐related targets varied among untreated OI bone isolates. When treated with SclAb, OI bone showed an upregulation in osteoblast and osteoblast progenitor markers, which was heterogeneous across tissue. Interestingly, the greatest magnitude of response generally corresponded to samples with low untreated expression of progenitor markers. Conversely, samples with high untreated expression of these markers showed a lower response to treatment. in vivo implanted OI bone showed a bone‐forming response to SclAb via μCT, which was corroborated by histomorphometry. SclAb induced downstream Wnt targets WISP1 and TWIST1, and elicited a compensatory response in Wnt inhibitors SOST and DKK1 in OI bone with the greatest magnitude from OI cortical bone. Understanding patients’ genetic, cellular, and morphological bone phenotypes may play an important role in predicting treatment response. This information may aid in clinical decision‐making for pharmacological interventions designed to address fragility in OI. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156449/2/jbm410377_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156449/1/jbm410377.pd
In-depth molecular profiling specifies human retinal microglia identity
Microglia are the tissue-resident macrophages of the retina and brain, being critically involved in organ development, tissue homeostasis, and response to cellular damage. Until now, little is known about the molecular signature of human retinal microglia and how it differs from the one of brain microglia and peripheral monocytes. In addition, it is not yet clear to what extent murine retinal microglia resemble those of humans, which represents an important prerequisite for translational research. The present study applies fluorescence-activated cell sorting to isolate human retinal microglia from enucleated eyes and compares their transcriptional profile with the one of whole retinal tissue, human brain microglia as well as classical, intermediate and non-classical monocytes. Finally, human retinal microglia are compared to murine retinal microglia, isolated from Cx3cr1
GFP/+ mice. Whereas human retinal microglia exhibited a high grade of similarity in comparison to their counterparts in the brain, several enriched genes were identified in retinal microglia when compared to whole retinal tissue, as well as classical, intermediate, and non-classical monocytes. In relation to whole retina sequencing, several risk genes associated with age-related macular degeneration (AMD) and diabetic retinopathy (DR) were preferentially expressed in retinal microglia, indicating their potential pathophysiological involvement. Although a high degree of similarity was observed between human and murine retinal microglia, several species-specific genes were identified, which should be kept in mind when employing mouse models to investigate retinal microglia biology. In summary, this study provides detailed insights into the molecular profile of human retinal microglia, identifies a plethora of tissue-specific and species-specific genes in comparison to human brain microglia and murine retinal microglia, and thus highlights the significance of retinal microglia in human retinal diseases and for translational research approaches
Alteration of Lung Physiology with the Administration of Convalescent Plasma in ARDS Patients Intubated with COVID-19 Pneumonia
**Background:** It remains unknown to what degree lung physiology is altered by administration of convalescent plasma in patients intubated with ARDS due to COVID-19 pneumonia. Although no longer clinically used as treatment for COVID-19, convalescent plasma therapy could be deployed again should new virus threats emerge in the future. **Aim:** To evaluate changes in ventilator physiologic variables in response to convalescent plasma transfusion using a retrospective, observational, case control study of intubated patients with COVID-19 pneumonia. **Methods:** Patients who were receiving mechanical ventilation due to COVID-19 at the time of administration of convalescent plasma therapy (CPT) were matched to control patients who did not receive convalescent plasma. Ventilatory data such as compliance, positive end-expiratory pressure (PEEP), FiO~2~ administered, PaO~2~/FiO~2~ ratio, and tidal volume were collected pre and post administration. Panel-level random-effects linear regression models were used to assess the mean difference and interactions between CPT and cases vs controls over time. **Results:** 12 patients received CPT while intubated and were matched to 35 intubated control patients who did not receive CPT. In total, 857 separate measurements of static compliance were obtained over time. No significant difference in static compliance was seen after CPT. In cases, adjusted mean static compliance was 30.8 (95% CI (23.3, 38.4))mL/cm H~2~O before CPT and 28.2 (95% CI (20.7,35.6)) mL/cm H~2~O afterwards. Controls adjusted mean static compliance was 33.9 (95% CI (29.5, 38.4)) mL/cm H~2~O before versus 32.2 (95% CI (27.9, 36.5)) mL/cm H~2~O afterwards. Variables that had small but statistically significant differences pre vs post CPT among cases and controls were systolic and diastolic blood pressure, FiO~2~, heart rate, applied PEEP, and respiratory rate. **Conclusion:** While some statistically significant physiologic effects were seen with CPT in mechanically ventilated patients, these were deemed to be small and clinically insignificant. This is consistent with prior research on less acutely ill COVID-19 patients
Differences in enteric methane emissions across four dairy production systems in the urbanizing environment of an Indian megacity
Low- and middle-income countries (LMICs) are rapidly urbanizing, leading to a high demand for high-quality animal products. Production increase is seen as a key to meeting this demand and reducing the global environmental impact of low-yielding dairy production system (DPS) often found in LMICs. Therefore, the present study assesses the relationship between enteric methane emissions and different dairy production strategies, taking DPS in the rural–urban interface of Bengaluru, an Indian megacity, as a case study. Twenty-eight dairy farms, evenly distributed across four DPS, were monitored for 1 year (eight visits at 6-week intervals). Following IPCC 2006 guidelines and a Tier 2 approach, enteric methane emissions from dairy cattle were calculated as carbon dioxide equivalents (CO2 eq). Dairy producers in ExtDPS, an extensive DPS found throughout the rural–urban interface of Bengaluru, fed their dairy cattle a high-quality diet, partly based on organic wastes from markets or neighbors, achieving 9.4 kg energy-corrected milk (ECM) per cow and day. Dairy producers in Semi-ADPS, a semi-intensive and rural DPS, fed an average quality diet and achieved the lowest milk production (7.9 kg ECM cow−1 day−1; p < 0.05). Dairy producers in Semi-BDPS, another semi-intensive and rural DPS, relied on average quality but more abundant feedstuffs and achieved a production of 10.0 kg ECM cow−1 day−1. A similar milk yield (10.1 kg ECM cow−1 day−1) was achieved by IntDPS, an intensive and rural DPS. The intensity of enteric methane emissions was the highest in Semi-BDPS (1.38 kg CO2-eq kg−1 ECM; p < 0.05), lowest in ExtDPS (0.79 kg CO2-eq kg−1 ECM; p < 0.05), and intermediate in semi-ADPS and IntDPS. The results highlight the close relationship between the intensity of enteric methane emissions and the intensification strategies chosen by dairy producers based on locally available resources. They also underline the importance of region- and system-specific environmental assessments of production systems in LMICs
Evidence that Meningeal Mast Cells Can Worsen Stroke Pathology in Mice
Stroke is the leading cause of adult disability and the fourth most common cause of death in the United States. Inflammation is thought to play an important role in stroke pathology, but the factors that promote inflammation in this setting remain to be fully defined. An understudied but important factor is the role of meningeal-located immune cells in modulating brain pathology. Although different immune cells traffic through meningeal vessels en route to the brain, mature mast cells do not circulate but are resident in the meninges. With the use of genetic and cell transfer approaches in mice, we identified evidence that meningeal mast cells can importantly contribute to the key features of stroke pathology, including infiltration of granulocytes and activated macrophages, brain swelling, and infarct size. We also obtained evidence that two mast cell-derived products, interleukin-6 and, to a lesser extent, chemokine (C-C motif) ligand 7, can contribute to stroke pathology. These findings indicate a novel role for mast cells in the meninges, the membranes that envelop the brain, as potential gatekeepers for modulating brain inflammation and pathology after stroke
The Naturalistic Flight Deck System: An Integrated System Concept for Improved Single-Pilot Operations
This paper reviews current and emerging operational experiences, technologies, and human-machine interaction theories to develop an integrated flight system concept designed to increase the safety, reliability, and performance of single-pilot operations in an increasingly accommodating but stringent national airspace system. This concept, know as the Naturalistic Flight Deck (NFD), uses a form of human-centered automation known as complementary-automation (or complemation) to structure the relationship between the human operator and the aircraft as independent, collaborative agents having complimentary capabilities. The human provides commonsense knowledge, general intelligence, and creative thinking, while the machine contributes specialized intelligence and control, extreme vigilance, resistance to fatigue, and encyclopedic memory. To support the development of the NFD, an initial Concept of Operations has been created and selected normal and non-normal scenarios are presented in this document
Solution Structure of LC4 Transmembrane Segment of CCR5
CC-chemokine receptor 5 (CCR5) is a specific co-receptor allowing the entry of human immunodeficiency virus type 1 (HIV-1). The LC4 region in CCR5 is required for HIV-1 entry into the cells. In this study, the solution structure of LC4 in SDS micelles was elucidated by using standard 1H two-dimensional NMR spectroscopy, circular dichroism, and fluorescdence quenching. The LC4 structure adopts two helical structures, whereas the C-terminal part remains unstructured. The positions in which LC4 binds to the HIV-1 inhibitory peptide LC5 were determined by docking calculations in addition to NMR data. The poses showed the importance of the hydrophobic interface of the assembled structures. The solution structure of LC4 elucidated in the present work provides a structural basis for further studies on the HIV-1 inhibitory function of the LC4 region
Soil organic carbon dynamics and crop yield for different crop rotations in a degraded ferruginous tropical soil in a semi-arid region: a simulation approach
In recent years, simulation models have been used as a complementary tool for research and for quantifying soil carbon sequestration under widely varying conditions. This has improved the understanding and prediction of soil organic carbon (SOC) dynamics and crop yield responses to soil and climate conditions and crop management scenarios. The goal of the present study was to estimate the changes in SOC for different cropping systems in West Africa using a simulation model. A crop rotation experiment conducted in Farakô-Ba, Burkina Faso was used to evaluate the performance of the cropping system model (CSM) of the Decision Support System for Agrotechnology Transfer (DSSAT) for simulating yield of different crops. Eight crop rotations that included cotton, sorghum, peanut, maize and fallow, and three different management scenarios, one without N (control), one with chemical fertilizer (N) and one with manure applications, were studied. The CSM was able to simulate the yield trends of various crops, with inconsistencies for a few years. The simulated SOC increased slightly across the years for the sorghum–fallow rotation with manure application. However, SOC decreased for all other rotations except for the continuous fallow (native grassland), in which the SOC remained stable. The model simulated SOC for the continuous fallow system with a high degree of accuracy normalized root mean square error (RMSE)=0·001, while for the other crop rotations the simulated SOC values were generally within the standard deviation (s.d.) range of the observed data. The crop rotations that included a supplemental N-fertilizer or manure application showed an increase in the average simulated aboveground biomass for all crops. The incorporation of this biomass into the soil after harvest reduced the loss of SOC. In the present study, the observed SOC data were used for characterization of production systems with different SOC dynamics. Following careful evaluation of the CSM with observed soil organic matter (SOM) data similar to the study presented here, there are many opportunities for the application of the CSM for carbon sequestration and resource management in Sub-Saharan Africa
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