GenomeMUSter mouse genetic variation service enables multitrait, multipopulation data integration and analysis.

Hundreds of inbred mouse strains and intercross populations have been used to characterize the function of genetic variants that contribute to disease. Thousands of disease-relevant traits have been characterized in mice and made publicly available. New strains and populations including consomics, the collaborative cross, expanded BXD, and inbred wild-derived strains add to existing complex disease mouse models, mapping populations, and sensitized backgrounds for engineered mutations. The genome sequences of inbred strains, along with dense genotypes from others, enable integrated analysis of trait-variant associations across populations, but these analyses are hampered by the sparsity of genotypes available. Moreover, the data are not readily interoperable with other resources. To address these limitations, we created a uniformly dense variant resource by harmonizing multiple data sets. Missing genotypes were imputed using the Viterbi algorithm with a data-driven technique that incorporates local phylogenetic information, an approach that is extendable to other model organisms. The result is a web- and programmatically accessible data service called GenomeMUSter, comprising single-nucleotide variants covering 657 strains at 106.8 million segregating sites. Interoperation with phenotype databases, analytic tools, and other resources enable a wealth of applications, including multitrait, multipopulation meta-analysis. We show this in cross-species comparisons of type 2 diabetes and substance use disorder meta-analyses, leveraging mouse data to characterize the likely role of human variant effects in disease. Other applications include refinement of mapped loci and prioritization of strain backgrounds for disease modeling to further unlock extant mouse diversity for genetic and genomic studies in health and disease.

Mechanical loading of joint modulates T cells in lymph nodes to regulate osteoarthritis.

OBJECTIVE: The crosstalk of joint pathology with local lymph nodes in osteoarthritis (OA) is poorly understood. We characterized the change in T cells in lymph nodes following load-induced OA and established the association of the presence and migration of T cells to the onset and progression of OA. METHODS: We used an in vivo model of OA to induce mechanical load-induced joint damage. After cyclic tibial compression of mice, we analyzed lymph nodes for T cells using flow cytometry and joint pathology using histology and microcomputed tomography. The role of T-cell migration and the presence of T-cell type was examined using T-cell receptor (TCR)α-/- mice and an immunomodulatory drug, Sphingosine-1-phosphate (S1P) receptor inhibitor-treated mice, respectively. RESULTS: We demonstrated a significant increase in T-cell populations in local lymph nodes in response to joint injury in 10, 16, and 26-week-old mice, and as a function of load duration, 1, 2, and 6 weeks. T-cell expression of inflammatory cytokine markers increased in the local lymph nodes and was associated with load-induced OA progression in the mouse knee. Joint loading in TCRα-/- mice reduced both cartilage degeneration (Osteoarthritis Research Society International (OARSI) scores: TCRα 0.568, 0.981-0.329 confidence interval (CI); wild type (WT) 1.328, 2.353-0.749 CI) and osteophyte formation. Inhibition of T-cell egress from lymph nodes attenuated load-induced cartilage degradation (OARSI scores: Fingolimod: 0.509, 1.821-0.142 CI; Saline 1.210, 1.932-0.758 CI) and decreased localization of T cells in the synovium. CONCLUSIONS: These results establish the association of lymph node-resident T cells in joint damage and suggest that the S1P receptor modulators and T-cell immunotherapies could be used to treat OA.

Motion correction of 3D dynamic contrast-enhanced ultrasound imaging without anatomical B-Mode images: Pilot evaluation in eight patients.

BACKGROUND: Dynamic contrast-enhanced ultrasound (DCE-US) is highly susceptible to motion artifacts arising from patient movement, respiration, and operator handling and experience. Motion artifacts can be especially problematic in the context of perfusion quantification. In conventional 2D DCE-US, motion correction (MC) algorithms take advantage of accompanying side-by-side anatomical B-Mode images that contain time-stable features. However, current commercial models of 3D DCE-US do not provide side-by-side B-Mode images, which makes MC challenging. PURPOSE: This work introduces a novel MC algorithm for 3D DCE-US and assesses its efficacy when handling clinical data sets. METHODS: In brief, the algorithm uses a pyramidal approach whereby short temporal windows consisting of three consecutive frames are created to perform local registrations, which are then registered to a master reference derived from a weighted average of all frames. We applied the algorithm to imaging studies from eight patients with metastatic lesions in the liver and assessed improvements in original versus motion corrected 3D DCE-US cine using: (i) frame-to-frame volumetric overlap of segmented lesions, (ii) normalized correlation coefficient (NCC) between frames (similarity analysis), and (iii) sum of squared errors (SSE), root-mean-squared error (RMSE), and r-squared (R2) quality-of-fit from fitted time-intensity curves (TIC) extracted from a segmented lesion. RESULTS: We noted improvements in frame-to-frame lesion overlap across all patients, from 68% ± 13% without correction to 83% ± 3% with MC (p = 0.023). Frame-to-frame similarity as assessed by NCC also improved on two different sets of time points from 0.694 ± 0.057 (original cine) to 0.862 ± 0.049 (corresponding MC cine) and 0.723 ± 0.066 to 0.886 ± 0.036 (p ≤ 0.001 for both). TIC analysis displayed a significant decrease in RMSE (p = 0.018) and a significant increase in R2 goodness-of-fit (p = 0.029) for the patient cohort. CONCLUSIONS: Overall, results suggest decreases in 3D DCE-US motion after applying the proposed algorithm.

Parathyroid hormone 1 receptor signaling mediates breast cancer metastasis to bone in mice.

Bone metastases are a common complication of breast cancer. We have demonstrated that intermittent administration of parathyroid hormone (PTH[1-34]) reduces the incidence of bone metastases in murine models of breast cancer by acting on osteoblasts to alter the bone microenvironment. Here, we examined the role of signaling mediated by PTH 1 receptor (PTH1R) in both osteoblasts and breast cancer cells in influencing bone metastases. In mice with impaired PTH1R signaling in osteoblasts, intermittent PTH did not reduce bone metastasis. Intermittent PTH also did not reduce bone metastasis when expression of PTH1R was knocked down in 4T1 murine breast cancer cells by shRNA. In 4T1 breast cancer cells, PTH decreased expression of PTH-related protein (PTHrP), implicated in the vicious cycle of bone metastases. Knockdown of PTHrP in 4T1 cells significantly reduced migration toward MC3T3-E1 osteoblasts, and migration was further inhibited by treatment with intermittent PTH. Conversely, overexpression of PTHrP in 4T1 cells increased migration toward MC3T3-E1 osteoblasts, and this was not inhibited by PTH. In conclusion, PTH1R expression is crucial in both osteoblasts and breast cancer cells for PTH to reduce bone metastases, and in breast cancer cells, this may be mediated in part by suppression of PTHrP.

Osteoblast Lineage Support of Hematopoiesis in Health and Disease.

In mammals, hematopoiesis migrates to the bone marrow during embryogenesis coincident with the appearance of mineralized bone, where hematopoietic stem cells (HSCs) and their progeny are maintained by the surrounding microenvironment or niche, and sustain the entirety of the hematopoietic system. Genetic manipulation of niche factors and advances in cell lineage tracing techniques have implicated cells of both hematopoietic and nonhematopoietic origin as important regulators of hematopoiesis in health and disease. Among them, cells of the osteoblast lineage, from stromal skeletal stem cells to matrix-embedded osteocytes, are vital niche residents with varying capacities for hematopoietic support depending on stage of differentiation. Here, we review populations of osteoblasts at differing stages of differentiation and summarize the current understanding of the role of the osteoblast lineage in supporting hematopoiesis. © 2022 American Society for Bone and Mineral Research (ASBMR).

Sex-Specific Differences in Gsα-Mediated Signaling Downstream of PTH1R Activation by Abaloparatide in Bone.

Teriparatide, recombinant parathyroid hormone (PTH[1-34]), and abaloparatide, an analogue of PTH related-peptide (PTHrP[1-34]), are both anabolic medications for osteoporosis that target the PTH receptor PTH1R. PTH1R is a G protein-coupled receptor, and the stimulatory Gs protein is an important mediator of the anabolic actions of PTH1R activation in bone. We have published that mice lacking the α subunit of Gs in osteoprogenitors do not increase bone mass in response to PTH(1-34). Unexpectedly, however, PTH(1-34) still increases osteoblast numbers and bone formation rate in male mice, suggesting that PTH1R may have both Gs-dependent and -independent actions in bone. Here we examine the role of Gs signaling in the anabolic actions of abaloparatide. We find that abaloparatide increases bone formation in male mice with postnatal deletion of Gsα in Osx-expressing osteoprogenitors (P-GsαOsxKO mice) but not in female P-GsαOsxKO mice. Therefore, abaloparatide has anabolic effects on bone in male but not female mice that appear to be independent of Gs-mediated signaling. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Teaching forceps: the impact of proactive faculty.

OBJECTIVE: The objective of the study was to evaluate the impact on resident forceps experience by a single proactive teacher. STUDY DESIGN: A study was performed to assess the impact on delivery statistics and outcome following the assignment of a single attending to teach forceps to residents. A 2 year period immediately preceding and 2 years following the study was compared using χ(2) and Student t tests. RESULTS: After appointment of the specific teaching attending, forceps deliveries increased by 59% (8% of all births), whereas vacuum procedures decreased to 3% of births (P < .0001) compared with the prior 2 years. The overall percentage of operative vaginal deliveries remained unchanged (11%). Cesarean section rates were unchanged during the study period at 27% of all births. Perineal laceration, 5 minute Apgar less than 7, and birth injuries were also not statistically different. There were fewer fetal pH events less than 7.1 in the teaching period (P = .003). CONCLUSION: In the population studied, there was an association between increasing resident forceps use and a positive impact on birth outcomes from the designation of a full-time, experienced, and proactive faculty member to obstetrics teaching duty.

First-trimester visualization of the fourth ventricle in fetuses with and without spina bifida.

OBJECTIVES: The purpose of this study was to examine the efficacy of nonvisualization of the fourth ventricle for first-trimester detection of spina bifida. METHODS: A total of 250 digitally stored sonographic examinations at gestational ages of 11 weeks to 13 weeks 6 days (245 normal and 5 randomly interspersed spina bifida cases) were retrospectively analyzed by 4 blinded reviewers for the presence or absence of the fourth ventricle followed by an anteroposterior ventricular dimension measurement. The ventricle size was related to the crown-rump length and gestational age by linear regression analysis and Pearson correlation. RESULTS: The fourth ventricle was identified in 971 of 1000 image readings (97.1%). False-negative and false-positive readings occurred in 11 of 20 (55.0%) and 20 of 980 (2.0%) cases, respectively (sensitivity, 0.45; specificity, 0.98.). False-negative and false-positive readings were evenly distributed throughout the gestational age range. When the ventricular size was measurable, its mean dimensions increased linearly with gestational age and were below the fifth percentile in 10 of 245 (4.0%) normal and 0 of 4 spina bifida cases, respectively. Intraclass correlation coefficient estimates were calculated based on the 2-way analysis of variance model and found to be 0.30 for a single rater and 0.64 for the mean of 4 raters. CONCLUSIONS: Nonvisualization of the first-trimester fourth ventricle is a less robust screening parameter for spina bifida than previously published.

[The human microbiome].

The complex microbial populations that colonize the human body form the human microbiome. The human microbiota may contain 1014) cells, an order of magnitude greater than the number of the human cells, and can express 100 times more genes than the human genome. The metagenome is the collective genomes of the human and its microbial flora. Major international colLaborative efforts currently explore the diverse human microbiomes from five different body areas: the nasopharyngeal, gastrointestinal and female urogenital tracts, the oral cavity and the skin. Defining the complexity of the human microbiome in health and disease will enhance the understanding of multiple pathological mechanisms and facilitate the development of novel diagnostic tools and therapeutic interventions.

Discordance of first-trimester crown-rump length is a predictor of adverse outcomes in structurally normal euploid dichorionic twins.

OBJECTIVE: The purpose of this study was to determine the association between discordant crown-rump length (CRL) measurements in structurally normal euploid dichorionic twins and adverse pregnancy outcomes. METHODS: This retrospective cohort study included women with dichorionic twins who underwent chorionic villus sampling and delivered in our facility from January 2000 to September 2007. Only pregnancies with viable twin fetuses and normal karyotypes were included. The association between CRL discordance, defined as a CRL discrepancy of 9% or greater, and adverse pregnancy outcomes was evaluated. RESULTS: Seventy-eight women met inclusion criteria and included 24 discordant twins (group 1) and 54 concordant twins (group 2). Maternal ages were similar: mean ± SD, 38.2 ± 3.1 years in group 1 versus 39.2 ± 3.9 years in group 2 (P = not significant). The median gestational ages at delivery were 35.6 ± 3.1 weeks in group 1 and 37.3 ± 2.0 weeks in group 2 (P < .01). At least 1 major complication occurred in 19 women (79%) in group 1 and 25 (46%) in group 2 (P = .01). Group 1 had significantly more major complications overall (P = .0008). Preterm premature rupture of membranes occurred in 10 women (42%) in group 1 and 6 (11%) in group 2 (P = .005). Delivery before 37 weeks' gestation occurred in 19 of 24 women (79%) in group 1 and 24 of 54 (44%) in group 2 (P = .006). There was a significant difference for younger gestational age at delivery in the discordant group (P < .01). CONCLUSIONS: Our data suggest that there is an increased risk of adverse pregnancy outcomes in chromosomally normal dichorionic twins with first-trimester discordant CRL measurements. These results may be clinically useful for counseling, management, and antenatal surveillance.