Semi-automatic proximal humeral trabecular bone density assessment tool: technique application and clinical validation

PURPOSE

This study aimed to apply a newly developed semi-automatic phantom-less QCT (PL-QCT) to measure proximal humerus trabecular bone density based on chest CT and verify its accuracy and precision.

METHODS

Subcutaneous fat of the shoulder joint and trapezius muscle were used as calibration references for PL-QCT BMD measurement. A self-developed algorithm based on a convolution map was utilized in PL-QCT for semi-automatic BMD measurements. CT values of ROIs used in PL-QCT measurements were directly used for phantom-based quantitative computed tomography (PB-QCT) BMD assessment. The study included 376 proximal humerus for comparison between PB-QCT and PL-QCT. Two sports medicine doctors measured the proximal humerus with PB-QCT and PL-QCT without knowing each other's results. Among them, 100 proximal humerus were included in the inter-operative and intra-operative BMD measurements for evaluating the repeatability and reproducibility of PL-QCT and PB-QCT.

RESULTS

A total of 188 patients with 376 shoulders were involved in this study. The consistency analysis indicated that the average bias between proximal humerus BMDs measured by PB-QCT and PL-QCT was 1.0 mg/cc (agreement range - 9.4 to 11.4; P > 0.05, no significant difference). Regression analysis between PB-QCT and PL-QCT indicated a good correlation (R-square is 0.9723). Short-term repeatability and reproducibility of proximal humerus BMDs measured by PB-QCT (CV: 5.10% and 3.41%) were slightly better than those of PL-QCT (CV: 6.17% and 5.64%).

CONCLUSIONS

We evaluated the bone quality of the proximal humeral using chest CT through the semi-automatic PL-QCT system for the first time. Comparison between it and PB-QCT indicated that it could be a reliable shoulder BMD assessment tool with acceptable accuracy and precision. This study developed and verify a semi-automatic PL-QCT for assessment of proximal humeral bone density based on CT to assist in the assessment of proximal humeral osteoporosis and development of individualized treatment plans for shoulders.

Trigger finger at the wrist caused by an intramuscular lipoma within the carpal tunnel: A case report

BACKGROUND

Trigger finger at the wrist, which occurs with finger movement, is an uncommon presentation. Few reports describing cases of trigger finger at the wrist have been published. Thus, we present a case of an intramuscular lipoma arising from an anomalous flexor digitorum muscle belly in a 48-year-old female patient causing painful finger triggering at the wrist and carpal tunnel syndrome (CTS).

CASE SUMMARY

A 48-year-old woman with complaints of a catching sensation during wrist motion and a progressive tingling sensation on the palmar aspect of the right hand for approximately 2 years was referred to our hospital. Triggering of the index to middle finger was evident with a palpable and audible clunk over the carpal tunnel during passive motion. Tinel’s sign was positive over the carpal tunnel of the right wrist with a positive Phalen’s test. Nerve conduction studies of the median nerve demonstrated a right CTS. Ultrasound examination revealed a 2.5 cm × 2.0 cm subcutaneous hyperechoic mass with no obvious blood flow at the wrist of the right arm. Surgical excision of the tumor and muscle mass led to a resolution of the patient’s symptoms, and any triggering or discomfort disappeared. The patient has had no evidence of recurrence at more than 1 year of follow-up.

CONCLUSION

Triggering of the fingers at the wrist is rare. It must be noted that there are many possible causes and types of triggering or clicking around the wrist. Accurate diagnosis is mandatory to avoid inaccurate treatment of patients with trigger wrist. During the diagnosis and treatment of CTS, attention should be paid to the variation of tendon tissue in the carpal tunnel, to avoid only focusing on the release of transverse carpal ligament and ignoring the removal of anomalous muscle belly.

Complete chloroplast genome sequence of Oxytropis glabra (Leguminosae)

Oxytropis glabra DC. is a perennial poisonous plant to livestock belonging to the genus Oxytropis, Leguminosae, mainly distributed in Northwestern China. As a poisonous grass, this species protects plant diversity in degraded grasslands by sheltering adjacent plants. In this study, the complete chloroplast genome with a total size of 122,094 bp was reported. Our annotations showed that the chloroplast genome contains 109 genes, including 76 protein-coding genes, 29 tRNA genes, and four rRNA genes. This work presents complete chloroplast genome information, which will be valuable for studying the evolution and genetic diversity of O. glabra.

Complete plastid genome sequence of Halimodendron halodendron (Leguminosae)

Halimodendron halodendron (Pall.) Voss. is a deciduous shrub belonging to the genus Halimodendron, Leguminosae, and is mainly distributed in dry areas. This species can be used for saline-alkali soil improvement and sand fixation. The complete plastid genome of H. halodendron first reported here is 129,342 bp in length, and contains 110 genes, including 76 protein coding genes, 30 tRNA genes, and 4 rRNA genes. A total of 105 simple sequence repeats (SSRs) were identified in the chloroplast genome. This information will be useful for study on the evolution and genetic diversity of Halimodendron halodendron in the future.

Complete chloroplast genome sequence of Peganum harmala (Zygophyllaceae)

Peganum harmala L. is a perennial herbaceous plant belonging to the family of Zygophyllaceae, and is grows in semi-arid climates, such as Xinjiang, Gansu, Ningxia, Qinghai, and Inner Mongolia in China, and also Middle East and North Africa. This species is of high medicinal value. The complete chloroplast genome was reported in this study. The chloroplast genome with a total size of 159,957 bp consists of two inverted repeats (IR, 26,550 bp) separated by a large single-copy region (LSC, 88,098 bp) and a small single-copy region (SSC, 18,759 bp). Further annotation revealed the chloroplast genome contains 113 genes, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. A total of 90 simple sequence repeats (SSRs) were identified in the chloroplast genome. This information will be useful for study on the evolution and genetic diversity of Peganum harmala in the future.

Complete chloroplast genome sequence of Sphaerophysa salsula (Leguminosae)

Sphaerophysa salsula (Pall.) DC. is a perennial herbaceous plant belonging to the genus Sphaerophysa, Galegeae, Leguminosae, and is mainly distributed in dry areas in Central Asia and Northwest China. The complete chloroplast genome with a total size of 123,300 bp was reported in this study. Further annotation revealed the chloroplast genome contains 109 genes, including 76 protein coding genes, 29 tRNA genes, and four rRNA genes. A total of 107 simple sequence repeats (SSRs) from mononucleotide to hexa-nucleotide repeat motif were identified in the chloroplast genome. This information will be useful for study on the evolution and genetic diversity of Sphaerophysa salsula in the future.

Complete chloroplast genome sequence of Thermopsis turkestanica Gand. (Leguminosae)

Thermopsis turkestanica Gand. is a perennial herbaceous plant belonging to the genus Thermopsis, Leguminosae, and is mainly distributed in dry areas. Most of the species in this genus have high medicinal value. The complete chloroplast genome was reported in this study. The chloroplast genome with a total size of 149,551 bp consists of two inverted repeats (IRs, 24,159 bp) separated by a large single-copy region (LSC, 83,692 bp) and a small single-copy region (SSC, 17,541 bp). Further annotation revealed the chloroplast genome contains 110 genes, including 77 protein coding genes, 29 tRNA genes, and four rRNA genes. This information will be useful for study on the evolution and genetic diversity of Thermopsis turkestanica in the future.

Interaction between Schwann cells and other cells during repair of peripheral nerve injury

Peripheral nerve injury (PNI) is common and, unlike damage to the central nervous system injured nerves can effectively regenerate depending on the location and severity of injury. Peripheral myelinating glia, Schwann cells (SCs), interact with various cells in and around the injury site and are important for debris elimination, repair, and nerve regeneration. Following PNI, Wallerian degeneration of the distal stump is rapidly initiated by degeneration of damaged axons followed by morphologic changes in SCs and the recruitment of circulating macrophages. Interaction with fibroblasts from the injured nerve microenvironment also plays a role in nerve repair. The replication and migration of injury-induced dedifferentiated SCs are also important in repairing the nerve. In particular, SC migration stimulates axonal regeneration and subsequent myelination of regenerated nerve fibers. This mobility increases SC interactions with other cells in the nerve and the exogenous environment, which influence SC behavior post-injury. Following PNI, SCs directly and indirectly interact with other SCs, fibroblasts, and macrophages. In addition, the inter- and intracellular mechanisms that underlie morphological and functional changes in SCs following PNI still require further research to explain known phenomena and less understood cell-specific roles in the repair of the injured peripheral nerve. This review provides a basic assessment of SC function post-PNI, as well as a more comprehensive evaluation of the literature concerning the SC interactions with macrophages and fibroblasts that can influence SC behavior and, ultimately, repair of the injured nerve.

Melatonin combined with chondroitin sulfate ABC promotes nerve regeneration after root-avulsion brachial plexus injury

After nerve-root avulsion injury of the brachial plexus, oxidative damage, inflammatory reaction, and glial scar formation can affect nerve regeneration and functional recovery. Melatonin (MT) has been shown to have good anti-inflammatory, antioxidant, and neuroprotective effects. Chondroitin sulfate ABC (ChABC) has been shown to metabolize chondroitin sulfate proteoglycans and can reduce colloidal scar formation. However, the effect of any of these drugs alone in the recovery of nerve function after injury is not completely satisfactory. Therefore, this experiment aimed to explore the effect and mechanism of combined application of melatonin and chondroitin sulfate ABC on nerve regeneration and functional recovery after nerve-root avulsion of the brachial plexus. Fifty-two Sprague-Dawley rats were selected and their C5-7 nerve roots were avulsed. Then, the C6 nerve roots were replanted to construct the brachial plexus nerve-root avulsion model. After successful modeling, the injured rats were randomly divided into four groups. The first group (injury) did not receive any drug treatment, but was treated with a pure gel-sponge carrier nerve-root implantation and an ethanol-saline solution via intraperitoneal (i.p.) injection. The second group (melatonin) was treated with melatonin via i.p. injection. The third group (chondroitin sulfate ABC) was treated with chondroitin sulfate ABC through local administration. The fourth group (melatonin + chondroitin sulfate ABC) was treated with melatonin through i.p. injection and chondroitin sulfate ABC through local administration. The upper limb Terzis grooming test was used 2-6 weeks after injury to evaluate motor function. Inflammation and oxidative damage within 24 hours of injury were evaluated by spectrophotometry. Immunofluorescence and neuroelectrophysiology were used to evaluate glial scar, neuronal protection, and nerve regeneration. The results showed that the Terzis grooming-test scores of the three groups that received treatment were better than those of the injury only group. Additionally, these three groups showed lower levels of C5-7 intramedullary peroxidase and malondialdehyde. Further, glial scar tissue in the C6 spinal segment was smaller and the number of motor neurons was greater. The endplate area of the biceps muscle was larger and the structure was clear. The latency of the compound potential of the myocutaneous nerve-biceps muscle was shorter. All these indexes were even greater in the melatonin + chondroitin sulfate ABC group than in the melatonin only or chondroitin sulfate ABC only groups. Thus, the results showed that melatonin combined with chondroitin sulfate ABC can promote nerve regeneration after nerve-root avulsion injury of the brachial plexus, which may be achieved by reducing oxidative damage and inflammatory reaction in the injury area and inhibiting glial scar formation.

Quinacrine pretreatment reduces microwave-induced neuronal damage by stabilizing the cell membrane

Quinacrine, widely used to treat parasitic diseases, binds to cell membranes. We previously found that quinacrine pretreatment reduced microwave radiation damage in rat hippocampal neurons, but the molecular mechanism remains poorly understood. Considering the thermal effects of microwave radiation and the protective effects of quinacrine on heat damage in cells, we hypothesized that quinacrine would prevent microwave radiation damage to cells in a mechanism associated with cell membrane stability. To test this, we used retinoic acid to induce PC12 cells to differentiate into neuron-like cells. We then pretreated the neurons with quinacrine (20 and 40 mM) and irradiated them with 50 mW/cm² microwaves for 3 or 6 hours. Flow cytometry, atomic force microscopy and western blot assays revealed that irradiated cells pretreated with quinacrine showed markedly less apoptosis, necrosis, and membrane damage, and greater expression of heat shock protein 70, than cells exposed to microwave irradiation alone. These results suggest that quinacrine stabilizes the neuronal membrane structure by upregulating the expression of heat shock protein 70, thus reducing neuronal injury caused by microwave radiation.

KLF7-transfected Schwann cell graft transplantation promotes sciatic nerve regeneration

Our former study demonstrated that Krüppel-like Factor 7 (KLF7) is a transcription factor that stimulates axonal regeneration after peripheral nerve injury. Currently, we used a gene therapy approach to overexpress KLF7 in Schwann cells (SCs) and assessed whether KLF7-transfected SCs graft could promote sciatic nerve regeneration. SCs were transfected by adeno-associated virus 2 (AAV2)-KLF7 in vitro. Mice were allografted by an acellular nerve (ANA) with either an injection of DMEM (ANA group), SCs (ANA+SCs group) or AAV2-KLF7-transfected SCs (ANA+KLF7-SCs group) to assess repair of a sciatic nerve gap. The results indicate that KLF7 overexpression promoted the proliferation of both transfected SCs and native SCs. The neurite length of the dorsal root ganglia (DRG) explants was enhanced. Several beneficial effects were detected in the ANA+KLF7-SCs group including an increase in the compound action potential amplitude, sciatic function index score, enhanced expression of PKH26-labeling transplant SCs, peripheral myelin protein 0, neurofilaments, S-100, and myelinated regeneration nerve. Additionally, HRP-labeled motoneurons in the spinal cord, CTB-labeled sensory neurons in the DRG, motor endplate density and the weight ratios of target muscles were increased by the treatment while thermal hyperalgesia was diminished. Finally, expression of KLF7, NGF, GAP43, TrkA and TrkB were enhanced in the grafted SCs, which may indicate that several signal pathways may be involved in conferring the beneficial effects from KLF7 overexpression. We concluded that KLF7-overexpressing SCs promoted axonal regeneration of the peripheral nerve and enhanced myelination, which collectively proved KLF-SCs as a novel therapeutic strategy for injured nerves.

Contribution of the GSTP1 gene polymorphism to the development of osteosarcoma in a Chinese population

We conducted a case-control study to investigate the associations between GSTT1, GSTM1, and GSTP1 gene polymorphisms and development of osteosarcoma in a Chinese population. Between January 2013 and February 2015, 153 patients diagnosed with osteosarcoma and 252 control subjects were enrolled in the current study from the Orthopedic Hospital of the Second Hospital of Jilin University. The GSTM1, GSTT1, and GSTP1 gene polymorphisms were detected by polymerase chain reaction coupled with restriction fragment length polymorphism analysis. As determined by a multiple-logistic regression analysis, the Val/Val genotype of GSTP1 was associated with a significantly increased risk of osteosarcoma compared to that of the Ile/Ile genotype, with an odds ratio (OR) = 3.39, and a 95% confidence interval (CI) = 1.45-8.13. Moreover, the Ile/Val+Val/Val genotype of GSTP1 was correlated with a marginally significant increased risk of osteosarcoma compared to that of the Ile/Ile genotype (OR = 1.65, 95%CI = 1.08-2.53). However, we did not find any significant associations between the GSTM1 and GSTT1 gene polymorphisms and osteosarcoma risk. In conclusion, our results suggest that the GSTP1 gene polymorphism is associated with an increased risk of osteosarcoma, whereas the GSTM1 and GSTT1 gene polymorphisms may not influence the development of this cancer.