Global, regional prevalence, and risk factors of osteoporosis according to the World Health Organization diagnostic criteria: a systematic review and meta-analysis.

This systematic review and meta-analysis estimated the global, regional prevalence, and risk factors of osteoporosis. Prevalence varied greatly according to countries (from 4.1% in Netherlands to 52.0% in Turkey) and continents (from 8.0% in Oceania to 26.9% in Africa). Osteoporosis is a common metabolic bone disorder in the elderly, usually resulting in bone pain and an increased risk of fragility fracture, but few summarized studies have guided global strategies for the disease. Therefore, we pooled the epidemiologic data to estimate the global, regional prevalence, and potential risk factors of osteoporosis. We conducted a comprehensive literature search through PubMed, EMBASE, Web of Science, and Scopus, to identify population-based studies that reported the prevalence of osteoporosis based on the World Health Organization (WHO) criteria. Meta-regression and subgroup analyses were used to explore the sources of heterogeneity. The study was registered in the PROSPERO database (CRD42021285555). Of the 57,933 citations evaluated, 108 individual studies containing 343,704 subjects were included. The global prevalence of osteoporosis and osteopenia was 19.7% (95%CI, 18.0%-21.4%) and 40.4% (95%CI, 36.9%-43.8%). Prevalence varied greatly according to countries (from 4.1% in Netherlands to 52.0% in Turkey) and continents (from Oceania 8.0% to 26.9% in Africa). The prevalence was higher in developing countries (22.1%, 95%CI, 20.1%-24.1%) than in developed countries (14.5%, 95%CI, 11.5%-17.7%). Our study indicates a considerable prevalence of osteoporosis among the general population based on WHO criteria, and the prevalence varies substantially between countries and regions. Future studies with robust evidence are required to explore risk factors to provide effective preventive strategies for the disease.

Calculating the spectrum of anisotropic waveguides using a spectral method.

The computation of the spectrum of a waveguide with arbitrary anisotropy with spatial dependence is a challenging task due to the coupling between axial and azimuthal harmonics. This problem is tackled in cylindrical coordinates by extending a spectral method for the general case. By considering the matrix representation of the operator on the right-hand side of the governing equations, the latter are exactly reformulated as an infinite set of integro-differential equations. Essential part of this study is taking into account the coupling of different harmonics, which becomes evident from the kernels of these equations. Provided a waveguide is translationally invariant in the axial direction, the coupling of axial harmonics vanishes. A practical approximation and truncation procedure yields a generalized eigenvalue problem, which can be solved numerically to obtain the entire spectrum of the operator and to construct the dispersion curves for the eigenmodes. The spectral method is tested against the results from the measurements of dispersion curves for the monopole, dipole, and quadrupole normal modes of scaled boreholes in tilted transverse isotropy anisotropic rock sample. Besides, the comparison of dispersion curves calculated by the spectral method and those computed from the synthetic data is discussed.

Auditory efferent dysfunction in normal-hearing chronic idiopathic tinnitus.

OBJECTIVE: To investigate the function of the auditory efferent system in patients with chronic idiopathic tinnitus, but normal pure-tone audiograms. METHODS: We studied 15 subjects with normal hearing that had experienced either unilateral or bilateral persistent tinnitus for at least 3 months. The ears of the 15 subjects were classified into tinnitus-positive-ear (TPE) and tinnitus-negative-ear (TNE) groups. The control-ear group (CE) comprised the ears of 15 subjects with normal hearing and no tinnitus. We measured different types of otoacoustic emissions (OAEs), including spontaneous (SOAEs), transient evoked (TEOAEs), and distortion product (DPOAEs). We also analyzed contralateral suppression of OAEs and auditory brainstem responses (ABRs). Data were compared among TPE, TNE, and CE groups. RESULTS: The data associated with cochlear mechanics, including the prevalence of SOAEs, the number of SOAE peaks, and the overall TEOAE responses in the absence of a contralateral stimulus, were not significantly different among the TPE, TNE, and CE groups. In the TPE group, contralateral stimuli failed to significantly suppress overall TEOAEs, and contralateral suppression of DPOAEs was significantly reduced over a limited frequency range. Furthermore, the TPE group showed prolonged latencies in waves III and V of ABRs. CONCLUSION: This study demonstrated that abnormal contralateral suppression of OAEs and ABRs indicated a dysfunction in the ipsilateral efferent medial olivocochlear system; this might play a role in normal-hearing tinnitus.

A Computer-Assisted Diagnostic Method for Accurate Detection of Early Nondisplaced Fractures of the Femoral Neck.

Nondisplaced femoral neck fractures are sometimes misdiagnosed by radiographs, which may deteriorate into displaced fractures. However, few efficient artificial intelligent methods have been reported. We developed an automatic detection method using deep learning networks to pinpoint femoral neck fractures on radiographs to assist physicians in making an accurate diagnosis in the first place. Our proposed accurate automatic detection method, called the direction-aware fracture-detection network (DAFDNet), consists of two steps, namely region-of-interest (ROI) segmentation and fracture detection. The first step removes the noise region and pinpoints the femoral neck region. The fracture-detection step uses a direction-aware deep learning algorithm to mark the exact femoral neck fracture location in the region detected in the first step. A total of 3840 femoral neck parts in anterior-posterior (AP) pelvis radiographs collected from the China Medical University Hospital database were used to test our method. The simulation results showed that DAFDNet outperformed the U-Net and DenseNet methods in terms of the IOU value, Dice value, and Jaccard value. Our proposed DAFDNet demonstrated over 94.8% accuracy in differentiating non-displaced Garden type I and type II femoral neck fracture cases. Our DAFDNet method outperformed the diagnostic accuracy of general practitioners and orthopedic surgeons in accurately locating Garden type I and type II fracture locations. This study can determine the feasibility of applying artificial intelligence in a clinical setting and how the use of deep learning networks assists physicians in improving correct diagnoses compared to the current traditional orthopedic manual assessments.

A Combination of FPU-Net and Feature Clustering Methods for Accurate Segmentation of Femoral Neck in Radiographic Diagnosis.

In this study, we develop an innovative method that assists computer-aided diagnosis in the determination process of the exact location of the femoral neck junction in plain radiographs. Our algorithm consists of two phases, i.e., coarse prediction and fine matching, which are implemented by supervised deep learning method and unsupervised clustering, respectively. In coarse prediction, standard masks are first produced by a specialist and trained in our proposed feature propagation network (FPU-Net) with supervised learning on the femoral neck dataset. In fine matching, the standard masks are first classified into different categories using our proposed three parameters with unsupervised learning. The predicted mask from FPU-Net is matched with each category of standard masks by calculating the values of intersection of union (IOU), and finally the predicted mask is substituted by the standard mask with the largest IOU value. A total of 4320 femoral neck parts in anterior-posterior (AP) pelvis radiographs collected from China Medical University Hospital database were used to test our method. Simulation results show that, on the one hand, compared with other segmentation methods, the method proposed in this paper has a larger IOU value and better suppression of noise outside the region of interest; on the other hand, the introduction of unsupervised learning for fine matching can help in the accurate localization segmentation of femoral neck images. Accurate femoral neck segmentation can assist surgeons to diagnose and reduce the misdiagnosis rate and burden.

Diagnostic value of combining bilateral electrocochleography results for unilateral Ménière's disease.

We defined 'an interaural difference in the summating potential/action potential (SP/AP) ratio from the ipsilateral hearing-impaired side to the contralateral normal-hearing side of > or =0.15' as a positive result for a novel 'relative criterion' for the diagnosis of unilateral Ménière's disease. A uniform result could be derived only between a positive ECoG result and the side of disease in 78.7% subjects by conventional absolute criterion (SP/AP > or =0.42). By adding the relative criterion, we found that the diagnostic value increased greatly in specificity (91.2%) and increased slightly in positive predictive rate (79.2%), but decreased greatly in sensitivity (28.8%) and decreased slightly in negative predictive rate (52.5%). In addition, we verified which ear had the disease in all positive cases.

High molecular weight polyethylene nanospheres: synthesis, physical and mechanical properties--second harmonic generation.

The weak second harmonic light generating from carbon nanotubes are detected. The signal intensity closely related to the density of pi-bonds attributed to the defects in the rolled graphene sheets, which is stimulated to have anharmonic oscillation as strongly affected by the environment. The intensities of SHG are diminished in order of well-aligned multi-wall carbon nanotubes (MWCNTs), randomly-aligned MWCNTs, and then to single-wall CNTs.

Using human plasma supplemented medium to cultivate human bone marrow-derived mesenchymal stem cell and evaluation of its multiple-lineage potential.

The objective of this study was to evaluate the proliferation and the multiple-lineage differentiation capacity when bone marrow mesenchymal stem cells (BMSCs) were cultured short-term in autologous serum/plasma instead of fetal calf serum (FCS). The BMSCs from 12 donors were cultivated individually in 10% autogenic plasma or serum, with or without bFGF and EGF growth factors. Cell proliferation was examined by a Tetrazolium assay (MTT) after passages 1, 3, and 5. A medium supplemented with 10% human plasma or serum was sufficient to propagate BMSCs. However, no significant proliferation was shown when bFGF and EGF (20 ng/mL each) were added into the medium with autologous serum/plasma. We examined, inductions of adipogenesis, osteogenesis, and chondrocytogenesis, as capacities of multiple-lineage differentiation of cultivated BMSCs (passages 8). Differentiation was investigated by both RT-PCR and immunohistochemistry staining (IHC). Qualitative evidence demonstrated the differentiation capacity was preserved in cultivated BMSCs with autologous serum/plasma.

Improving the diagnosis of LV non-compaction with cardiac magnetic resonance imaging.

BACKGROUND: Current diagnostic criteria for left ventricular non-compaction (LVNC) poorly correlate with clinical outcomes. We aimed to develop a cardiac magnetic resonance (CMR) based semi-automated technique for quantification of non-compacted (NC) and compacted (C) masses and to ascertain their relationships to global and regional LV function. METHODS: We analysed CMR data from 30 adults with isolated LVNC and 20 controls. NC and C masses were measured using relative signal intensities of myocardium and blood pool. Global and regional LVNC masses was calculated and correlated with both global and regional LV systolic function as well as occurrence of arrhythmia. RESULTS: LVNC patients had significantly higher end-systolic (ES) and end-diastolic (ED) NC:C ratios compared to controls (ES 0.21 [SD 0.09] vs. 0.12 [SD 0.02], p<0.001; ED 0.39 [SD 0.08] vs. 0.26 [SD 0.05], p<0.001). NC:C ratios correlated inversely with global ejection fraction, with a stronger correlation in ES vs. ED (r=-0.58, p<0.001 vs. r=-0.30, p=0.03). ES basal, mid and apical NC:C ratios also showed a significant inverse correlation with global LV ejection fraction (ES basal r=-0.29, p=0.04; mid-ventricular r=-0.50, p<0.001 and apical r=-0.71, p<0.001). Upon ROC testing, an ES NC:C ratio of 0.16 had a sensitivity of 70% and a specificity of 95% for detection of significant LVNC. Patients with sustained ventricular tachycardia had a significantly higher ES NC:C ratio (0.31 [SD 0.18] vs. 0.20 [SD 0.06], p=0.02). CONCLUSIONS: The NC:C ratio derived from relative signal intensities of myocardium and blood pool improves the ability to detect clinically relevant NC compared to previous CMR techniques.

Prone and direct posterior approach for management of posterior column tibial plateau fractures.

INTRODUCTION: The three-column fixation concept is becoming popular in orthopedic practice. Posterior column fracture is an uncommon type of tibial plateau fracture. The supine position for the surgical approach is familiar to most surgeons; however, it is difficult to achieve good reduction and fixation in posterior column fracture. HYPOTHESES: The prone position and direct posterior approach can achieve proper reduction and fixation for posterior column tibial plateau fracture, yielding good functional outcome. MATERIALS AND METHODS: Between January 2010 and January 2012, 184 tibial plateau fractures were diagnosed and operated on in our institution. Sixteen posterior column tibial plateau fractures (10 male and 6 female patients, with a mean age of 41.5 ± 14.3 years) were diagnosed by preoperative plain films and CT scans. Ten patients presented with fracture-dislocation of the knee joint. A direct posterior approach in prone position was used to reduce the tibial condyle and fix it with an anti-glide buttress plate. Radiographic evaluation included reduction quality and bone union. Functional evaluation included Lysholm score and Tegner activity score. RESULTS: All fractures healed within 6 months, without secondary displacement. Ten knees had postoperative anatomic reduction (0mm step-off) and 6 had acceptable reduction (< 2mm step-off). At 34.4 ± 9.6 months, median extension was 3 (5-10) and flexion 135 (100-145). The mean Lysholm score was 95 (75-100) and the mean Tegner activity score was 6 (5-8). All patients were satisfied with the operation. No cases of post-traumatic osteoarthritis of the knee occurred during follow-up. CONCLUSIONS: The prone position and direct posterior approach has great advantages in terms of reduction and stable fixation, yielding good results.

Relaxin affects the shape of rat myometrial cells in culture.

The shape of rat myometrial cells in culture was altered by exposure to hormones. Oxytocin (107 microU/ml) significantly decreased mean cell length and area. Treatment of oxytocin-treated cells with relaxin (1.5 micrograms/ml), isoproterenol (10 microM) or (Bu)2 cAMP (1 mM) for 15 min resulted in a significant increase in cell length and area. The effect of relaxin was time dependent, with a significant increase in cell length by 1 min and in cell area by 3 min. Relaxin elicited a concentration-dependent increase in cell length and area between 0.1 and 2 micrograms/ml. The actions of relaxin correlate in time course and concentration dependence with its effects on cAMP elevation in the presence of 0.4 microM forskolin and on changes in myosin light chain kinase kinetic parameters in these cells. Myometrial cells in culture constitute a useful model system in which to correlate physical and biochemical effects of relaxin and other hormones.

Relaxin treatment alters the kinetic properties of myosin light chain kinase activity in rat myometrial cells in culture.

Relaxin treatment altered the kinetic properties of rat myometrial cell myosin light chain kinase (MLCK) by increasing the K50 of the enzyme for calmodulin (CaM) from 1.1 +/- 0.1 to 38 +/- 14 nM. When MLCK was assayed in the presence of 7 nM CaM to maximize the effect of the decreased affinity for CaM between control and relaxin-treated groups, a rapid concentration-dependent effect of the hormone was observed. Relaxin decreased MLCK activity significantly within 1 min. The ED50 of the effect was 0.4 microgram/ml. In addition to its effect on Ca2+-CaM-dependent activity, relaxin also decreased Ca2+-CaM-independent MLCK activity. This decrease was not attributable to a decrease in the affinity of the enzyme for myosin. There was a temporal association between the effects of relaxin on mean cell length, elevation of cAMP levels in the presence of 0.4 microM forskolin previously shown in other studies, and the alteration of MLCK activity. All three parameters were changed significantly within 1 min after exposure to relaxin. The ED50 of relaxin for cell shape changes, cAMP elevation, and effects on MLCK activity were all approximately 0.4 microgram/ml. Relaxin may act in part by a cAMP-mediated phosphorylation of MLCK, thereby decreasing its affinity for CaM. The effect on MLCK may be linked to a decrease in the phosphorylation of myosin light chains and the promotion of uterine relaxation.

Gonadotropins and estradiol stimulate immunoreactive insulin-like growth factor-I production by porcine granulosa cells in vitro.

Previous studies have established the ovarian granulosa cell as a site of insulin-like growth factor-I (IGF-I) secretion and action, suggesting an autocrine function for this peptide in the ovary. To better understand how this putative autocrine system is regulated and its interface with the classic ovarian trophic hormones FSH, LH, and estradiol (E2), we have studied the effects of these hormones on the secretion of immunoreactive IGF-I (iIGF-I) by cultured porcine granulosa cells. Immature granulosa cells were cultured under serum-free conditions which were optimized to allow maximal iIGF-I production and hormonal responsivity. Measurements of iIGF-I were made after minimizing the influence of IGF-binding proteins by either acid gel filtration or reverse phase chromatography. Since the two preparative procedures gave roughly comparable results, the more expeditious reverse phase procedure was chosen for most samples. Cycloheximide virtually eliminated measurable iIGF-I in culture, suggesting that the peptide measured was newly synthesized, and degradation of IGF-I by cultured granulosa cells was negligible. Consequently, the medium levels provided an accurate indication of cellular secretion over the collection period. Under optimal culture conditions, iIGF-I was readily measurable and responsive to treatment with ovarian trophic hormones. The iIGF-I levels in several experiments with these hormones were as follows: FSH treatment, 1.58 +/- 0.21 times the control value (n = 5 experiments); E2 treatment, 1.26 +/- 0.12 times the control value (n = 5); E2 plus FSH, 3.12 X 0.31 times the control value (n = 8); LH, 1.33 +/- 0.12 times the control value (n = 3); LH plus FSH, 1.78 +/- 0.2 times the control value (n = 1). To assess the role of cAMP in the mediation of gonadotropin effects in this system, granulosa cells were treated with a phosphodiesterase inhibitor (methylisobutylxanthine), which resulted in iIGF-I levels 1.61 +/- 0.7 times the control level. In the presence of FSH, a further stimulatory effect was demonstrated (3.76 +/- 0.29 times control). In addition, the cAMP analog 8-bromo-cAMP dramatically increased iIGF-I levels (6.3 +/- 0.72 times control). These data provide the first demonstration that gonadal iIGF-I secretion can be stimulated by the principal hormones involved in trophic regulation of the ovary. As with other gonadotropin-dependent functions of granulosa cells, this effect appears to be mediated by cAMP and enhanced by E2. This interface between circulating hormones and autocrine systems could provide an important mechanism to amplify the effects of gonadotropic hormones on a local level.

Concomitant effects of growth hormone on secretion of insulin-like growth factor I and progesterone by cultured porcine granulosa cells.

The observation that GH deficiency delays the onset of puberty has raised the question of the effect of GH on gonadal development. In addition, recent studies in the rat have indicated that GH is able to elevate ovarian levels of immunoreactive insulin-like growth factor I (iIGF-I) in vivo and enhance FSH-induced granulosa cell differentiation in vitro. To evaluate further the possibility of direct effects of GH on ovarian function, we have studied the action of GH on the secretion of iIGF-I and progesterone by cultured porcine granulosa cells from immature follicles. The effects of GH were compared with those of estradiol (E2) and FSH, hormones previously shown to stimulate steroidogenesis and iIGF-I production in this system. GH-stimulated cultures secreted 7.8 times as much iIGF-I per cell as control cultures, while cultures treated with E2 plus FSH secreted 4.5 times as much, and the combination of all three hormones produced an additional increment. The GH-dependent immunoreactivity was localized to two peaks on gel filtration which coeluted with authentic IGF-I and with an IGF-binding protein. In contrast to the results with iIGF-I secretion, GH was a relatively ineffective stimulator of progesterone secretion, resulting in levels 2.6 times the control value, compared to levels 7.4-fold the control value in cultures treated with E2 plus FSH. However, when the three agonists were combined, a synergistic interaction was observed which resulted in progesterone values 33.3 times the control value. In parallel studies, PRL was unable to mimic the effects of GH on iIGF-I or progesterone secretion. In summary, GH has direct stimulatory actions on porcine granulosa cells. Compared to E2 and FSH, established stimulators of these cells, GH is at least comparable in effectiveness with regard to iIGF-I secretion, but less effective as a stimulator of steroidogenesis. However, GH dramatically enhances the effects of E2 and FSH on progesterone secretion. These effects of GH could be important during the onset of puberty, when GH levels in plasma are elevated.

Polyamines and autocrine control of tumor growth by prolactin in experimental breast cancer in culture.

We have previously observed that both polyamines and an autocrine mechanism are involved in the stimulation by ovine PRL (oPRL) of growth of the N-nitrosomethylurea-induced rat mammary tumor cultured in vitro in the soft agar clonogenic assay. These experiments were designed to test the interaction between these two pathways of oPRL action in this system. In agreement with previous findings in our laboratory, conditioned medium obtained from oPRL-treated (oPRL-CM), but not untreated, tumors consistently stimulated colony formation when added to N-nitrosomethylurea mammary tumors plated in soft agar under serum-free medium conditions. Administration of alpha-difluoromethyl-ornithine (DFMO), an irreversible inhibitor of polyamine biosynthesis, abolished the colony-stimulating effect of oPRL-CM. The inhibitory effect of DFMO was reversed in a dose-dependent fashion by the addition of spermidine, which entirely restored the growth-promoting action of oPRL-CM. In addition, the administration of increasing amounts of spermidine potentiated the colony-stimulating effect of suboptimal concentrations of oPRL-CM. In contrast, manipulation of the polyamine environment with DFMO and/or spermidine administration did not affect the number of colonies formed when conditioned medium from untreated tumors was added instead of oPRL-CM. We conclude that the polyamine pathways plays an essential role in the expression of autocrine control of tumor growth by oPRL.

The effect of relaxin on cyclic adenosine 3',5'-monophosphate concentrations in rat myometrial cells in culture.

Relaxin, a uterine relaxant secreted by the corpus luteum, was able to elevate cAMP concentrations in the presence of 1-methyl-3-isobutyl xanthine (MIX) (0.1 mM) or forskolin (0.4 microM) in a time- and dose-dependent manner in rat myometrial cells in culture but not in stromal cells. The optimal culture conditions for the cAMP response were determined to be an initial plating density of 1-1.5 X 10(6) cells/ml (3 ml/35-mm dish) and a 2-day culture period. In the presence of MIX, the time course of cAMP elevation in response to relaxin exhibited a lag phase of more than 5 min before cAMP concentrations rose significantly. However, in the presence of forskolin, relaxin elevated cAMP within 1 min. The concentration-response relationships were almost identical in the presence of MIX or forskolin. Isoproterenol was able to increase cAMP concentrations in myometrial cultures in both the absence and presence of MIX and to elevate cAMP levels rapidly within 1 min. These data suggest that cAMP could play some role in the initiation of uterine relaxation mediated by relaxin.

Neurogenic regulation of lipid metabolism in the rabbit. A mechanism for the cholesterol-lowering effect of acupuncture.

Plasma and aortic cholesterol levels are known to fall significantly after needling at the specific point which is innervated by a branch of the deep peroneal nerve. Different types of stimulation were applied to the specific nerve, using solely needling, injection of normal saline with needling and injection of a small dose of novocain with needling at the specific point in several groups of rabbits fed a high cholesterol diet for two or three weeks. Significant decreases in plasma and aortic cholesterol were obtained in the combined acupuncture group after one or two weeks of acupuncture. When the specific point was blocked by injection of a larger dose of novocain or the deep peroneal nerve was cut, then needling at the specific point lost its hypocholesterolemic effect. It is thus suspected that stimulation of sensory receptors of the deep peroneal nerve at the specific point may be the mechanism of the cholesterol-lowering action of acupuncture.