Associations of intrauterine exposure to manganese with fetal and early-childhood growth: a prospective prenatal cohort study.

Prenatal manganese (Mn) exposure may be related to poor birth outcomes; however, there are few relevant epidemiological reports on the effects of intrauterine Mn levels on intrauterine fetal and early childhood growth. From 2013 to 2016, 2082 pairs of mothers and infants were recruited in Wuhan, China, who provided an entire set of urine samples during their first, second, and third trimesters. Fetal head circumference (HC), abdominal circumference (AC), femoral length (FL), and estimated fetal weight (EFW) were obtained by ultrasound at the 16, 24, and 31 weeks of pregnancy. When the children were born, 6 months old, 12 months old, and 24 months old, their weight, height, weight-for-height, and BMI were measured. We used generalized linear models, generalized estimated equations, and restricted cubic spline curves (RCS) to investigate the linear and nonlinear relationships between antenatal Mn levels and fetal and early childhood growth. In all fetuses, Mn exposure during the 1st and 2nd gestation was associated with decreased fetal AC, FL, and EFW at 24 weeks (e.g., for each doubling of urinary Mn concentrations during the 1st and 2nd gestation, the SD score of EFW at 24 weeks decreased by - 4.16% (95% CI, - 6.22%, - 2.10%) and - 3.78% (95% CI, - 5.86%, - 1.70%)). Mn concentrations in the highest tertile group of the 1st and 2nd gestation were related to decreased fetus growth parameters compared to the lowest tertile group. For each doubling of the average Mn concentrations during pregnancy, the z-scores of weight, weight-for-height, and BMI at 12 months decreased, with percentage changes of - 2.93% (95% CI, - 5.08%, - 0.79%), - 3.25% (95% CI, - 5.56%, - 0.94%), and - 3.09% (95% CI, - 5.44%, - 0.73%). In the RCS model, we found a reverse U-shaped association between 1st trimester Mn concentration and fetal FL at 16 weeks and HC at 31 weeks in male fetuses and a non-linear association between mean Mn concentration during pregnancy and girls' weight-for-height and BMI at 6 months. Intrauterine exposure to Mn may be related to restricted growth in the fetus and early childhood, especially in fetuses at 24 weeks of gestation and children at 12 months of age. Also, meaningful curvilinear relationships were found in the sex stratification.

Potential roles of gut microbiota in metal mixture and bone mineral density and osteoporosis risk association: an epidemiologic study in Wuhan.

Few studies have focused on the effects of multiple metal mixtures on bone health and the underlying mechanisms related to alterations in the gut microbiota. This study aimed to examine the potential roles of gut microbiota alterations in metal mixtures and their association with osteoporosis traits. Adults aged ≥ 55 years were recruited from two community healthcare centers in Wuhan City during 2016-2019. The plasma concentrations of six metals (zinc, iron, selenium, lead, cadmium, and arsenic) were measured using an inductively coupled plasma mass spectrometer. The k-means clustering method was employed to explore the exposure profiles of metal mixtures for all participants. 16S rRNA gene sequencing was used to profile the gut microbiota of participants. Combining these results with those of our previous study, we identified overlapping taxa and evaluated their potential roles. A total of 806 participants (516 females), with an average age of 67.36 years were included. The participants were grouped into three clusters using k-means clustering: Cluster 1 (n = 458), Cluster 2 (n = 199), and Cluster 3 (n = 149). The high-exposure group for iron, zinc, lead, and cadmium (Cluster 3) showed a negative association with lumbar spine 1-4 bone mineral density (BMD). A total of 201 individuals (121 females) underwent sequencing of the gut microbiota. Both alpha and beta diversities were statistically different among the three groups. Bacteroidaceae, Lachnospiraceae, Bifidobacteriaceae, Bacteroides, and Lachnospiraceae_incertae_sedis were identified as overlapping taxa associated with the metal mixtures and BMD. Interaction analysis revealed that Cluster 3 interacted with Bacteroidaceae/Bacteroides, resulting in a positive effect on LS1-4 BMD (ß = 0.358 g/cm2, 95% CI: 0.047 to 0.669, P = 0.025). Our findings indicate associations between multiple metal mixtures and BMD as well as gut microbiota alterations. Exploring the interaction between metal mixtures and the gut microbiota provides new perspectives for the precise prevention and treatment of osteoporosis.

Metal Artifacts Reduction in CT Scans using Convolutional Neural Network with Ground Truth Elimination.

Metal artifacts are very common in CT scans since metal insertion or replacement is performed for enhancing certain functionality or mechanism of patient's body. These streak artifacts could degrade CT image quality severely, and consequently, they could influence clinician's diagnosis. Many existing supervised learning methods approaching this problem assume the availability of clean images data, images free of metal artifacts, at the part with metal implant. However, in clinical practices, those clean images do not usually exist. Therefore, there is no support for the existing supervised learning based methods to work clinically. We focus on reducing the streak artifacts on the hip scans and propose a convolutional neural network based method to eliminate the need of the clean images at the implant part during model training. The idea is to use the scans of the parts near the hip for model training. Our method is able to suppress the artifacts in corrupted images, highly improve the image quality, and preserve the details of surrounding tissues, without using any clean hip scans. We apply our method on clinical CT hip scans from multiple patients and obtain artifact-free images with high image quality.

A novel approach for posterior acetabular fractures: Surgical technique.

This article describes a novel approach, the Direct Posterior Approach (DPA) for the treatment of posterior acetabular fractures (posterior column, posterior wall, or both posterior column and wall). This technique allows direct visualization of the entire posterior wall, part of the hip capsule and the posterior column between the space of the gluteus medius and the piriformis superiorly. The approach spares the division of short external rotators, abductors, and hip capsule, thus preventing iatrogenic damage to the medial femoral circumflex artery, sciatic nerve, and superior and inferior gluteal neurovascular bundles, as well as protecting the vascularity of the fracture fragments. In addition to the low blood loss, short operative time and low risk of iatrogenic injury, patients who are treated by the DPA approach exhibit positive functional recovery in follow-up. DPA is an effective, safe and minimally-invasive technique for the treatment of posterior acetabular fractures.

[Comparison on clinical features between dilated cardiomyopathy patients with or without pulmonary hypertension].

OBJECTIVE: The clinical data of dilated cardiomyopathy (DCM) patients with or without pulmonary hypertension (PH) diagnosed by echocardiography were compared. METHODS: During January 2007 to December 2009, 61 cases of DCM with PH and 51 cases of DCM without PH were admitted in our department. The demographic and clinical data, heart function, echocardiography and serum total bilirubin and creatinine levels of all patients were analyzed. RESULTS: Sex, age, vital signs, combined diseases and arrhythmias as well as the serum creatinine level [(103.5 ± 49.7) µmol/L vs. (90.3 ± 37.3) µmol/L, P > 0.05] were similar between the two groups, while the incidence of NYHA III and IV (95% vs. 65%), the left ventricle end-systolic dimension[(71.0 ± 9.6) mm vs. (65.5 ± 7.2) mm], dimension of the left atrium [(52.8 ± 8.93) mm vs. (43.9 ± 6.3) mm], right ventricular outflow tract [(29.1 ± 5.3) mm vs. (22.1 ± 3.3) mm] incidence of pericardial effusion (29/61 vs. 7/51) and the serum total bilirubin level [(45.3 ± 31.8) µmol/L vs. (19.5 ± 9.08) µmol/L] were significantly higher while ejective fraction was significantly lower in DCM with PH than those in DCM without PH (0.28 ± 0.10 vs. 0.36 ± 0.10, all P < 0.05). CONCLUSION: DCM patients with PH is linked with worse clinical features than DCM patients without PH.

[Establishment of a rabbit model of lumbar intervertebral disc degeneration via the paraspinal approach].

OBJECTIVE: To establish a rabbit model of intervertebral disc degeneration by puncturing the anulus fibrosus through an approach between the longissimus dorsi muscle and obliquus externus abdominis. METHODS: The L(4/5) and L(5/6) intervetebral discs of 6 New Zealand white rabbits were punctured by an 18-gauge pin in the anterolateral annular fibrosus through an approach between the longissimus dorsi muscle and the obliquus externus abdominis with the right transverse processes of L(5) and L(6) resected; the L(2/3) discs were used as the control without exposure or needle stab, and the L(3/4) discs were subjected to sham operation with the discs exposed but not punctured after resecting the right transverse process of L(4). X-ray and magnetic resonance imaging (MRI) were performed preoperatively and at the 4th week after puncture. At 4 weeks after the operation, histological and immunohistochemical analyses of the discs were carried out. RESULTS: X-ray of the punctured discs at 4 weeks after the operation presented a significant decrease of disc height, osteophytosis formation, and end-plate stiffness; an obvious decrease of signal intensity on T(2)-weighted images was found in the puncture group but not in the control or sham-operated groups. Gross morphological inspection showed atrophy of the nucleus pulposus, which became loose, soft, and fragile with a light yellow color. Histological and immunohistochemical analyses showed a significant decrease of notochordal cells and type II collagen in the nucleus pulposus in the puncture group as compared to the control and sham-operated groups. CONCLUSION: Puncture through the approach between the longissimus dorsi muscle and the obliquus externus abdominis allows the establishment of a reliable animal model for studying intervertebral disc degeneration.

Metformin stimulates osteoprotegerin and reduces RANKL expression in osteoblasts and ovariectomized rats.

Anti-diabetic drug metformin has been shown to enhance osteoblasts differentiation and inhibit osteoclast differentiation in vitro and prevent bone loss in ovariectomized (OVX) rats. But the mechanisms through which metformin regulates osteoclastogensis are not known. Osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) are cytokines predominantly secreted by osteoblasts and play critical roles in the differentiation and function of osteoclasts. In this study, we demonstrated that metformin dose-dependently stimulated OPG and reduced RANKL mRNA and protein expression in mouse calvarial osteoblasts and osteoblastic cell line MC3T3-E1. Inhibition of AMP-activated protein kinase (AMPK) and CaM kinase kinase (CaMKK), two targets of metformin, suppressed endogenous and metformin-induced OPG secretion in osteoblasts. Moreover, supernatant of osteoblasts treated with metformin reduced formation of tartrate resistant acid phosphatase (TRAP)-positive multi-nucleated cells in Raw264.7 cells. Most importantly, metformin significantly increased total body bone mineral density, prevented bone loss and decreased TRAP-positive cells in OVX rats proximal tibiae, accompanied with an increase of OPG and decrease of RANKL expression. These in vivo and in vitro studies suggest that metformin reduces RANKL and stimulates OPG expression in osteoblasts, further inhibits osteoclast differentiation and prevents bone loss in OVX rats.