Opportunistic use of lumbar computed tomography and magnetic resonance imaging for osteoporosis screening.

Compared with the healthy patients, patients with osteoporosis had a lower Hounsfield unit (HU) value and a higher vertebral bone quality (VBQ) score. Both the HU value and VBQ score can simply distinguish patients with osteoporosis (OP), with a cutoff value of HU value < 97.06 and VBQ score > 3.08. INTRODUCTION: The purpose of this study is to determine whether the opportunistic use of computed tomography (CT) or magnetic resonance imaging (MRI) is effective for identifying spine surgical patients with OP. METHODS: We retrospectively evaluated 109 lumbar spine surgery patients who received lumbar quantitative CT (QCT) and MRI. Using the area under the curve, the CT-based HU value and MRI-based VBQ score were calculated. Then, based on the QCT results, receiver operating characteristic (ROC) curves were constructed to determine the diagnostic performance of the HU value and VBQ score. RESULTS: The HU value was significantly lower in the OP group, and the VBQ score was significantly higher in the OP group. Using the area under the curve, the diagnostic performance of the HU value and VBQ score for OP were 0.959 and 0.880, respectively. The diagnostic threshold values determined with optimal sensitivity and specificity were an HU value of 97.06 and a VBQ score of 3.08. CONCLUSION: Opportunistic use of CT and MRI can simply distinguish patients with OP, which are expected to be potential alternatives to T-score for the osteoporosis screening.

Advances in Hounsfield units value for predicting cage subsidence on spinal interbody fusion surgery.

PURPOSE: A growing number of studies have demonstrated that Hounsfield units (HU) value can effectively assess bone quality and predict cage subsidence (CS) after spinal surgery. The purpose of this review is to provide an overview of the utility of the HU value for predicting CS after spinal surgery and to raise some of the unresolved questions in this field. METHODS: We searched on PubMed, EMBASE, MEDLINE, and Cochrane Library for studies correlating HU value to CS. RESULTS: Thirty-seven studies were included in this review. We found that HU value can predicted the risk of CS effectively after spinal surgery. Moreover, the HU value of the cancellous vertebral body and the cortical endplate were used for predicting CS, in comparison, the measurement method of HU value in the cancellous vertebral body was more standardized, but which region is more important to CS remains unknown. Different cutoff thresholds of HU value have been established in different surgical procedures for predicting CS. The HU value may be superior to dual-energy X-ray absorptiometry (DEXA) for CS prediction; however, the usage standard of HU value has not been well established. CONCLUSIONS: The HU value shows great potential for predicting CS and constitutes an advantage over DEXA. However, general consensuses about how CS is defined and HU is measured, which part of HU value is more important, and the appropriate cutoff threshold of the HU value for osteoporosis and CS still require exploration.

Modification of the 8th American Joint Committee on Cancer staging system for gallbladder carcinoma to improve prognostic precision.

BACKGROUND: The 8th edition of the American Joint Committee on Cancer (AJCC) staging system for gallbladder carcinoma (GBC) came into force since 2018. However, the prognostic precision of this staging system has not been properly assessed. This study aimed to evaluate the latest staging system and suggest modifications to improve its prognostic precision. METHODS: Data of patients with GBC was included from the Surveillance, Epidemiology and End Results (SEER) database (2004-2015) and multicenter database (2010-2017). Baseline clinicopathologic characteristics were recorded including age, sex, race, grade, T category, N category, M category and stage. The Kaplan-Meier method was used to plot survival functions. The prediction power of the AJCC 8th edition and its modified version were evaluated using the concordance index (C-index). RESULTS: A total of 2779 GBC patients were included in the SEER database and 591 were collected from multicenter database. While no significant difference in survival of patients was observed between stages IVA and IVB using the 8th AJCC staging system (p > 0.05), the prognosis of stage IIIA showed a slightly better outcome than stage IIIB (p = 0.046) in the SEER database. In the multicenter database, there was no significant difference between stage IIIA and stage IIIB (p > 0.05). Similarly, no significant difference in the survival of patients between stages IIIA and IIIB was observed when M0 patients with at least 6 lymph nodes (LNs) were analyzed (p > 0.05) for both SEER and multicenter database. On the other hand, a modified staging system was able to stratify patients from stage IIIA, stage IIIB and stage IV (p < 0.001). For the SEER database, the C-indexes of 8th AJCC staging system and that of its modified version were 0.709 and 0.742, respectively. For the multicenter database, the C-index of 8th AJCC staging system and that of our modified version were 0.635 and 0.679, respectively. CONCLUSIONS: The modified 8th staging system proposed in this study can improve the prognostic precision of the 8th AJCC staging system for GBC. We therefore suggest including these modifications in the next update of AJCC staging system for GBC.

Polyketide synthases mutation in tuberculosis transmission revealed by whole genomic sequence, China, 2011-2019.

Introduction: Tuberculosis (TB) is an infectious disease caused by a bacterium called Mycobacterium tuberculosis (Mtb). Previous studies have primarily focused on the transmissibility of multidrug-resistant (MDR) or extensively drug-resistant (XDR) Mtb. However, variations in virulence across Mtb lineages may also account for differences in transmissibility. In Mtb, polyketide synthase (PKS) genes encode large multifunctional proteins which have been shown to be major mycobacterial virulence factors. Therefore, this study aimed to identify the role of PKS mutations in TB transmission and assess its risk and characteristics. Methods: Whole genome sequences (WGSs) data from 3,204 Mtb isolates was collected from 2011 to 2019 in China. Whole genome single nucleotide polymorphism (SNP) profiles were used for phylogenetic tree analysis. Putative transmission clusters (≤10 SNPs) were identified. To identify the role of PKS mutations in TB transmission, we compared SNPs in the PKS gene region between "clustered isolates" and "non-clustered isolates" in different lineages. Results: Cluster-associated mutations in ppsA, pks12, and pks13 were identified among different lineage isolates. They were statistically significant among clustered strains, indicating that they may enhance the transmissibility of Mtb. Conclusion: Overall, this study provides new insights into the function of PKS and its localization in M. tuberculosis. The study found that ppsA, pks12, and pks13 may contribute to disease progression and higher transmission of certain strains. We also discussed the prospective use of mutant ppsA, pks12, and pks13 genes as drug targets.

Application and thinking of minimally invasive transforaminal lumbar interbody fusion in degenerative lumbar diseases.

Background: This study sought to investigate the clinical efficacy and safety of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of lumbar degenerative diseases. Methods: The clinical data of 55 patients with lumbar degenerative diseases treated at our hospital from January 2018 to January 2020 were analyzed retrospectively. Of the 55 patients, 35 who underwent MIS-TLIF were included in the MIS-TLIF group, and 20 who underwent posterior lumbar interbody fusion (PLIF) were included in the PLIF group. The visual analogue scale (VAS) score, Oswestry disability index (ODI) score, operation time, incision length, intraoperative bleeding, postoperative drainage, postoperative landing time, postoperative hospital stay, postoperative interbody fusion rate, and complications were compared between the two groups. Results: The patients in both groups were followed-up for at least 1.5 years (range, 18-30 months; with an average of 27.5±2.6 months). There was no significant difference in the operation time, incision length, intraoperative bleeding, VAS score for low back and leg pain, ODI score, interbody fusion rate, hospitalization expenses, and complication rate between the two groups (P>0.05). One patient had nail failure in the MIS-TLIF group, 1 patient in each group had nerve root irritation, and 1 patient in each group had superficial incision infection and local suture dehiscence. The postoperative drainage volume, postoperative landing time, and postoperative hospital stay of the MIS-TLIF group were less than those of the PLIF group (P<0.05). Conclusions: Compared to PLIF, the use of MIS-TLIF in the treatment of lumbar degenerative diseases has a number of advantages, including more complete intraoperative hemostasis, less postoperative drainage, earlier landing, and faster discharge, and also significantly improves postoperative lumbar discomfort.

Clustering Ensemble Based on Hybrid Multiview Clustering.

As an effective method for clustering applications, the clustering ensemble algorithm integrates different clustering solutions into a final one, thus improving the clustering efficiency. The key to designing the clustering ensemble algorithm is to improve the diversities of base learners and optimize the ensemble strategies. To address these problems, we propose a clustering ensemble framework that consists of three parts. First, three view transformation methods, including random principal component analysis, random nearest neighbor, and modified fuzzy extension model, are used as base learners to learn different clustering views. A random transformation and hybrid multiview learning-based clustering ensemble method (RTHMC) is then designed to synthesize the multiview clustering results. Second, a new random subspace transformation is integrated into RTHMC to enhance its performance. Finally, a view-based self-evolutionary strategy is developed to further improve the proposed method by optimizing random subspace sets. Experiments and comparisons demonstrate the effectiveness and superiority of the proposed method for clustering different kinds of data.

Influence of upscaling on identification of reservoir fluid properties using seismic-scale elastic constants.

Elastic constants derived from seismic-scale measurements are often used to infer subsurface petrophysical properties based on rock-physics relationships established from either theoretic model or core-scale measurements. However, the spatial heterogeneity of rock physical properties at the local scale has a significant impact on this relation. To understand this problem, we built a scaled physical model comprised of artificial porous layers with different pore fluids. After conducting a two-dimensional marine seismic survey over the physical model, the physical modeling data ware then used to retrieve the elastic constants of the layered package. The seismic-scale results reveal that the identification of reservoir fluid properties is improved using elastic constants that is more sensitive to pore fluid properties. The results of numerical simulations show that Lamé moduli provide more insight into rock properties and pore-fluid contents than P-wave impedances, and that the relationship between the upscaled elastic constants and the effective fluid bulk moduli at the seismic scale is usually not perfectly preserved at the reservoir scale. To interpret seismic-scale elastic constants for petrophysical properties, the rock physics relationship need to be carefully calibrated. The findings will help us understand the upscaling of rock-physics transform, which will improve the accuracy of geological property predictions from seismic-scale elastic constants.

Hybrid Incremental Ensemble Learning for Noisy Real-World Data Classification.

Traditional ensemble learning approaches explore the feature space and the sample space, respectively, which will prevent them to construct more powerful learning models for noisy real-world dataset classification. The random subspace method only search for the selection of features. Meanwhile, the bagging approach only search for the selection of samples. To overcome these limitations, we propose the hybrid incremental ensemble learning (HIEL) approach which takes into consideration the feature space and the sample space simultaneously to handle noisy dataset. Specifically, HIEL first adopts the bagging technique and linear discriminant analysis to remove noisy attributes, and generates a set of bootstraps and the corresponding ensemble members in the subspaces. Then, the classifiers are selected incrementally based on a classifier-specific criterion function and an ensemble criterion function. The corresponding weights for the classifiers are assigned during the same process. Finally, the final label is summarized by a weighted voting scheme, which serves as the final result of the classification. We also explore various classifier-specific criterion functions based on different newly proposed similarity measures, which will alleviate the effect of noisy samples on the distance functions. In addition, the computational cost of HIEL is analyzed theoretically. A set of nonparametric tests are adopted to compare HIEL and other algorithms over several datasets. The experiment results show that HIEL performs well on the noisy datasets. HIEL outperforms most of the compared classifier ensemble methods on 14 out of 24 noisy real-world UCI and KEEL datasets.

Efficient Vaccine Distribution Based on a Hybrid Compartmental Model.

To effectively and efficiently reduce the morbidity and mortality that may be caused by outbreaks of emerging infectious diseases, it is very important for public health agencies to make informed decisions for controlling the spread of the disease. Such decisions must incorporate various kinds of intervention strategies, such as vaccinations, school closures and border restrictions. Recently, researchers have paid increased attention to searching for effective vaccine distribution strategies for reducing the effects of pandemic outbreaks when resources are limited. Most of the existing research work has been focused on how to design an effective age-structured epidemic model and to select a suitable vaccine distribution strategy to prevent the propagation of an infectious virus. Models that evaluate age structure effects are common, but models that additionally evaluate geographical effects are less common. In this paper, we propose a new SEIR (susceptible-exposed-infectious sC recovered) model, named the hybrid SEIR-V model (HSEIR-V), which considers not only the dynamics of infection prevalence in several age-specific host populations, but also seeks to characterize the dynamics by which a virus spreads in various geographic districts. Several vaccination strategies such as different kinds of vaccine coverage, different vaccine releasing times and different vaccine deployment methods are incorporated into the HSEIR-V compartmental model. We also design four hybrid vaccination distribution strategies (based on population size, contact pattern matrix, infection rate and infectious risk) for controlling the spread of viral infections. Based on data from the 2009-2010 H1N1 influenza epidemic, we evaluate the effectiveness of our proposed HSEIR-V model and study the effects of different types of human behaviour in responding to epidemics.

Comparison of our self-designed rotary self-locking intramedullary nail and interlocking intramedullary nail in the treatment of long bone fractures.

OBJECTIVE: The purpose of this study is to compare the clinical effects of our self-designed rotary self-locking intramedullary nail (RSIN) and interlocking intramedullary nail (IIN) for long bone fractures. METHODS: A retrospective study was performed in 1,704 patients who suffered bone fractures and underwent RSIN or IIN operation in our hospital between March 1999 and March 2013, including 494 with femoral fractures, 572 with humeral fractures, and 638 with tibial fractures. Among them, 634 patients were followed up for more than 1 year. The operative time, intraoperative blood loss, postoperative complications, healing rate, and the excellent and good rate of functional recovery were compared between two groups. RESULTS: Compared with IIN group, RSIN group exhibited significantly shorter operative time and less intraoperative blood loss no matter for humeral, femoral, or tibial fractures (all p < 0.001). The healing rate in patients with more than 1 year follow-up was significantly higher in RSIN group for femoral and tibial fractures (both p < 0.05). In RSIN group, no nail breakage or loosening occurred, but radial nerve injury and incision infection were respectively observed in one patient with humeral fracture. In IIN group, nail breakage or loosening occurred in 7 patients with femoral fractures and 16 patients with tibial fractures, radial nerve injury was observed in 8 patients with humeral fractures, and incision infection was present in 2 patients with humeral fractures and 1 patient with femoral fracture. The complication rate of IIN group was significantly higher than that of RSIN group (p < 0.05). However, there were no significant differences in the excellent and good rate of shoulder, elbow, knee, and ankle joint functional recovery between RSIN group and IIN group. CONCLUSION: RSIN may be a reliable and practical alternative method for the treatment of long bone fractures.

Biomechanical analysis and clinical effects of bridge combined fixation system for femoral fractures.

This work aimed to compare the stress distribution and mechanical properties of our bridge combined fixation system and commonly used metal locking plate screw system by finite element analysis and by using the Zwick/Z100 testing machine. In addition, we also investigated the clinical outcome of our bridge combined fixation system for femoral fractures in 59 patients from June 2005 to January 2013. As a result, the stress distribution in the bone plate and screws of metal locking plate screw system during walking and climbing stairs was significantly lower than that of metal locking plate screw system. No significant difference in the displacement was observed between two systems. The equivalent bending stiffness of bridge combined fixation system was significantly lower than that of metal locking plate screw system. There were no significant differences in the bending strength, yield load, and maximum force between two systems. All the cases were followed up for 12-24 months (average 18 months). The X-ray showed bone callus was formed in most patients after 3 months, and the fracture line was faint and disappeared at 6-9 months postoperatively. No serious complications, such as implant breakage and wound infection, occurred postoperatively. According to self-developed standard for bone healing, clinical outcomes were rated as excellent or good in 55 out of 59 patients (success rate: 93.2%). Therefore, our findings suggest that our bridge combined fixation system may be a promising approach for treatment of long-bone fractures.

Immunomodulatory effectiveness of tacrolimus in preventing epidural scar adhesion after laminectomy in rat model.

There was no previous study about topical application of tacrolimus (FK506) could inhibit fibroblast proliferation and prevent epidural scar adhesion after laminectomy. We intended to illustrate the effect of FK506 on inhibiting fibroblast proliferation and preventing epidural scar adhesion after laminectomy in rat model. In our study, seventy-two rats were randomly divided into four groups (0.1mg/ml group, 0.05 mg/ml group, 0.01 mg/ml group and control group). Laminectomy was performed at Lumbar-1 level, and then different concentrations of FK506 and saline were applied to the laminectomy sites. Four weeks later the rats were killed and the epidural adhesion was evaluated. Macroscopic assessment, hydroxyproline content analysis, histological analysis and mRNA measurements were used to evaluate the effect of FK506 on reducing epidural scar adhesion. The results showed that FK506 could prevent epidural scar adhesion in a dose-dependent manner. Little epidural adhesions were seen in the laminectomy sites treated with 0.1mg/ml FK506. The hydroxyproline content, the number of fibroblasts, the mRNA expression level of IL-2 and TGF-ß1 in 0.1mg/ml FK506 group were significantly less than those of 0.05 mg/ml FK506 group, 0.01 mg/ml FK506 group and control group. However, dense epidural adhesions were found in 0.01 mg/ml FK506 group and control group. The hydroxyproline content and the number of fibroblasts in 0.01 mg/ml group showed no significant difference compared with those of control group. In conclusion, topical application of 0.1mg/ml FK506 could inhibit fibroblast proliferation and prevent epidural scar adhesion after laminectomy in rat model.

Vitamin D receptor BsmI polymorphism and osteoporosis risk: a meta-analysis from 26 studies.

OBJECTIVE: Growing evidence has shown that vitamin D deficiency can cause lower bone mineral density (BMD) and an increased risk of osteoporosis. Vitamin D receptor (VDR) BsmI polymorphism (rs1544410) can affect BMD variation and circulating osteocalcin levels. To date, a wide range of epidemiological studies have been carried out to evaluate the association between VDR BsmI polymorphism and susceptibility to osteoporosis. Conflicting results, however, were obtained. The aim of this study was to evaluate the effect of VDR BsmI polymorphism on osteoporosis risk using a meta-analysis. METHODS: Twenty-six publications were identified by searching PubMed and Embase databases. The association between VDR BsmI polymorphism and osteoporosis was estimated by calculating pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs). RESULTS: The bb genotype was associated with a significantly decreased risk of osteoporosis in overall comparison (bb vs. BB: OR=0.61, 95% CI, 0.40-0.92; bb vs. BB/Bb: OR=0.70, 95% CI, 0.52-0.95, respectively). Subgroup analyses showed that the bb genotype had a decreased risk of developing osteoporosis in postmenopausal women (bb vs. BB/Bb: OR=0.68, 95% CI, 0.46-0.98) and Africans (Bb/bb vs. BB: OR=0.18, 95% CI, 0.09-0.37). CONCLUSION: The VDR BsmI polymorphism may have a protective role against the development of osteoporosis.

[Modified retrograde rotative-type interlocking intramedullary nail for humeral shaft fractures].

OBJECTIVE: To improve the retrograde rotative-type interlocking intramedullary nail based on humeral bone dissection and clinical application, and investigate the clinical values of modified retrograde rotative-type interlocking intramedullary nail for humeral shaft fracture. METHODS: Between March 2006 and March 2010, 146 patients with humeral shaft fractures were treated and fractures were fixed with the modified retrograde rotative-type interlocking intramedullary nail (the modified group, n=73) and with the retrograde rotative-type interlocking intramedullary nail (the original group, n=73). In the original group, there were 40 males and 33 females with an average age of 41 years; 41 cases were classified as transverse fracture, 18 as oblique fracture, 8 as spiral fracure, and 6 as comminuted fracture; the median disease duration was 11 days (range, 3 hours to 2 months); and close reduction fixation was performed in 27 cases and open reduction fixation in 46 cases. In the modified group, there were 39 males and 34 females with an average age of 40 years; 43 cases were classified as transverse fracture, 16 as oblique fracture, 10 as spiral fracure, and 4 as comminuted fracture; the median disease duration was 13 days (range, 3 hours to 3 months); and close reduction fixation was performed in 31 cases and open reduction fixation in 42 cases. There was no significant difference in sex, age, fracture type, and disease duration between 2 groups (P > 0.05). The fracture healing and functional recovery of affected limbs were compared between 2 groups after operation. RESULTS: The operation time and intraoperative blood loss in the modified group were significantly less than those in the original group (P < 0.05). Iatrogenic fracture occurred in 3 cases of the original group, which were cleavage fracture of supracondylar. No iatrogenic fracture occurred in the modified group. All incisions of 2 groups healed by first intention without complications of postoperative infections, metal fracture, and loosening of internal fixation, etc. A total of 116 patients were followed up more than 12 months in 2 groups with 58 patients in each group. The fracture healing time was (15 +/- 3) weeks (fresh fracture) and (30 +/- 12) weeks (old fracture and nonunion) in the modified group, and was (16 +/- 4) weeks (fresh fracture) and (35 +/- 14) weeks (old fracture) in the original group, showing significant differences between 2 groups (P < 0.05). The results of Neer shoulder score were excellent in 65 cases and good in 8 cases, and the results of Aitken and Rorabeck elbow function score were excellent in 61 cases and good in 12 cases in the original group; the results of Neer shoulder score were excellent in 67 cases and good in 6 cases, and the results of Aitken and Rorabeck elbow function score were excellent in 63 cases and good in 10 cases; and the excellent and good rates were 100% in 2 groups. CONCLUSION: The modified retrograde rotative-type interlocking intramedullary nail has the advantages of easy operation and less complication, which is an effective and reliable internal fixator.