Association Between Malignant Diseases and Medication-Related Osteonecrosis of the Jaw (MRONJ): A Systematic Review and Meta-Analysis.

PURPOSE: The aim was to identify whether malignant diseases increase the risk of medication-related osteonecrosis of the jaw (MRONJ) occurrence when patients are exposed to bisphosphonate, antiresorptive or antiangiogenic drugs. To analyze related factors. METHODS: A systematic literature searching was performed in PubMed, Embase, and Google Scholar for studies with information about whether patients have malignant diseases. Patients involved must be treated with MRONJ-related drugs and at high risk of developing MRONJ. RESULTS: A total of 6 cohort studies and 3 case-control studies were included. Analysis according 9 studies shows that malignant diseases have significant influence on MRONJ occurrence (risk ratio (RR): 2.62; 95% confidence interval (95% CI): 1.58-4.33; P =0.0002). Subgroup analysis according 6 cohort studies also shows that malignant diseases significantly affect MRONJ occurrence (RR: 3.50; 95% CI: 1.63-7.52; P =0.001). Chemotherapy have no obvious influence on MRONJ occurrence (RR: 1.64; 95% CI: 0.79-3.39; P =0.18). Intravenous drug administration significantly influences MRONJ occurrence (RR: 2.67; 95% CI: 1.27-5.58; P =0.009). CONCLUSIONS: Patients with malignant diseases have higher risk of MRONJ occurrence when exposed to bisphosphonate, antiresorptive, or antiangiogenic drugs. Cumulative dosages from intravenous drugs administration contribute to MRONJ developing. Prevention of MRONJ in patients with malignancy should be emphasized.

Cloning of PmMYB6 in Pinus massoniana and an Analysis of Its Function.

Phenylpropanoids are crucial for the growth and development of plants and their interaction with the environment. As key transcriptional regulators of plant growth and development, MYB-like transcription factors play a vital role in the biosynthesis of phenylpropanoid metabolites. In this study, we functionally characterized PmMYB6, a Pinus massoniana gene that encodes an R2R3-MYB transcription factor. It was confirmed by qPCR that PmMYB6 was highly expressed in the flowers, xylem, and phloem of P. massoniana. By overexpressing PmMYB6 in tobacco and poplar, we found that transgenic plants had enlarged xylem, increased content of lignin and flavonoids, and up-regulated expression of several enzyme genes of the phenylpropane metabolism pathway to different degrees. The above research results indicate that PmMYB6 is involved in the metabolic flux distribution of different branches of the phenylpropane metabolic pathway, and the results may provide clues for the regulation of metabolic fluxes between flavonoids and the lignin biosynthesis pathways of P. massoniana, as well as provide a basis for the molecular breeding of P. massoniana.

Thermogravimetry combined with electrospray and atmospheric pressure chemical ionization mass spectrometry for characterization of synthetic polymers.

RATIONALE: Thermogravimetry (TG) combined with electrospray and atmospheric chemical ionization (ESI+APCI) mass spectrometry (MS) was developed to rapidly characterize thermal decomposition products of synthetic polymers and plastic products. The ESI-based TG-MS method is useful for characterizing thermally labile, nonvolatile, and polar compounds over an extensive mass range; and the APCI-based TG-MS counterpart is useful for characterizing volatile and nonpolar compounds. Both polar and nonpolar compounds can be simultaneously detected by ESI+APCI-based TG-MS. METHODS: Analytes with different volatility were produced from TG operated at different temperatures, which were delivered through a heated stainless-steel tube to the ESI+APCI source where they reacted with the primary charged species generated from electrospray and atmospheric pressure chemical ionization (ESI+APCI) of solvent and nitrogen. The analyte ions were then detected by an ion trap mass spectrometer. RESULTS: A semi-volatile PEG 600 standard was used as the sample and protonated and sodiated molecular ions together with adduct ions including [(PEG)n + 15]+ , [(PEG)n + 18]+ , and [(PEG)n + 29]+ were detected by TG-ESI+APCI-MS. The technique was further utilized to characterize thermal decomposition products of nonvolatile polypropylene glycol (PPG) and polystyrene (PS) standards, as well as a PS-made water cup and coffee cup lid. The characteristic fragments of PPG and PS with mass differences of 58 and 104 between respective ion peaks were detected at the maximum decomposition temperature (Tmax ). CONCLUSIONS: The information obtained from the TG-ESI+APCI-MS analysis is useful in rapidly distinguishing different types of polymers and their products. In addition, the signals of the additives in the polymer products, including antioxidants and plasticizers, were also detected before the TG temperature reached Tmax .

Characterization and Interaction Analysis of the Secondary Cell Wall Synthesis-Related Transcription Factor PmMYB7 in Pinus massoniana Lamb.

In vascular plants, the importance of R2R3-myeloblastosis (R2R3-MYB) transcription factors (TFs) in the formation of secondary cell walls (SCWs) has long been a controversial topic due to the lack of empirical evidence of an association between TFs and downstream target genes. Here, we found that the transcription factor PmMYB7, which belongs to the R2R3-MYB subfamily, is involved in lignin biosynthesis in Pinus massoniana. PmMYB7 was highly expressed in lignified tissues and upon abiotic stress. As a bait carrier, the PmMYB7 protein had no toxicity or autoactivation in the nucleus. Forty-seven proteins were screened from the P. massoniana yeast library. These proteins were predicted to be mainly involved in resistance, abiotic stress, cell wall biosynthesis, and cell development. We found that the PmMYB7 protein interacted with caffeoyl CoA 3-O-methyltransferase-2 (PmCCoAOMT2)-which is involved in lignin biosynthesis-but not with beta-1, 2-xylosyltransferase (PmXYXT1) yeast two-hybrid (Y2H) studies. Our in vivo coimmunoprecipitation (Co-IP) assay further showed that the PmMYB7 and PmCCoAOMT2 proteins could interact. Therefore, we concluded that PmMYB7 is an upstream TF that can interact with PmCCoAOMT2 in plant cells. These findings lay a foundation for further research on the function of PmMYB7, lignin biosynthesis and molecular breeding in P. massoniana.

Feruloylated Oligosaccharides from Maize Bran Modulated the Gut Microbiota in Rats.

Corn bran is a byproduct produced from corn milling; it is rich in ferulic acid and hemicellulose. In this research, the effects of feruloylated oligosaccharides (FOs) from maize bran on the microbial diversity and profiles in rat feces were investigated through 16S rRNA sequencing. FOs significantly increased bacterial richness and diversity compared with the control and xylooligosaccharides (XOS) alone. In comparison with the control group and the group administrated with XOS, FOs orally administered at 300 mg/kg increased OTU in feces by 57.0 and 24.8 %, and Chao value by 93.4 and 37.6 %, respectively. FOs also influenced obesity- and diabetes-associated bacteria. Oral administration of FOs at 300 mg/kg decreased the ratio of Firmicutes to Bacteroidetes from 477.7:1 to 55.1:1; greatly increased the reads of bacteria that were previously found resistant against diabetes in rats, such as Actinobacteria, Bacteroides, and Lactobacillus; whereas decreased diabetes-prone bacteria, such as Clostridium and Firmicutes.

Psychologic health status of patients undergoing orthognathic surgery.

BACKGROUND: The appearance and dysfunction of deformities may cause psychologic disorders in patients. The aim of this study was to assess the psychologic health status of patients undergoing orthognathic surgery and its relationship with demographic characteristics, social activityof the individuals, and severity of maxillofacial deformity. METHODS: As a tool for assessing the psychologic health status, the Symptom Checklist-90 (SCL-90) questionnaire was used on 318 patients undergoing orthognathic surgery at the Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, China from January 2006 to November 2012. t-Test was used to compare the psychologic health status between the 318 patients and 200 healthy volunteers. Variance analysis (analysis of variance) was applied for assessing the relationship between the psychologic health status and the variables of the study. RESULTS: The SCL-90 total score of the patients undergoing orthognathic surgery was higher than that of the healthy volunteers (P < 0.05). Results of the t-test revealed statistically significant difference (P < 0.05) in the symptom dimensions of obsessive-compulsive, interpersonal sensitivity, depression, and paranoid ideation. An association between sex and the SCL-90 total score was observed (F = 11.293; P = 0.001 and P <0.05). The patients who had regular work presented better psychological health status than did the patients who had no regular work (F = 8.008; P = 0.005 and P < 0.05). The patients who received comfort from family and relatives presented better psychological health status than did the patients who did not receive such help (F = 10.064; P = 0.002 and P < 0.05). The patients who received economic help from family and relatives presented better psychological health status than did the patients who did not receive such help (F = 9.789; P = 0.002 and P < 0.05). An association was found between severity of deformity and psychologic health (F = 6.394; P = 0.002 and P < 0.05). CONCLUSIONS: Patients with jaw deformity have significant psychologic problems and their psychologic health is affected by demographic characteristics, social activity of individuals, and severity of maxillofacial deformity.

Contrast analysis of open reduction and internal fixation and non-surgical treatment of condylar fracture: a meta-analysis.

BACKGROUND: To take surgical treatment or non-surgical treatment on condylar fracture, clinicians are faced with a difficult choice. Traditional treatment on condylar fracture advocated non-surgical treatment, including intermaxillary traction and intermaxillary fixation, which relies mainly on condylar rebuilt. In recent years, with the development of rigid internal fixation, open reduction and internal fixation technique has been well applied in the treatment of condylar fracture and has obtained an optimistic therapeutic effect. More and more of patients with condylar fracture are advised to undergo surgical treatment. However, surgical treatment sometimes causes some discomforts and complications to patients. Is surgery treatment inevitable for condylar fracture? We, in this study, adopted a meta-analysis to compare the efficacy of open reduction and fixation surgical treatment with that of the non-surgical treatment on condylar fracture to give a reference to clinic. METHODS: Computer retrieval of PubMed, Cochrane Library, and EMbase was used to identify literatures that reported the efficacy of open reduction and fixation surgical treatment compared with that of the non-surgical treatment on condylar fracture. Retrieval time began from the establishment of database to January 2012. Two reviewers assessed the quality of each trial and extracted data independently. RevMan 5.0 software was used for statistical analysis. RESULTS: Thirteen literatures including 859 patients were included. A total of 409 patients underwent surgical treatment and 450 patients underwent non-surgical treatment. The results of the meta-analysis showed that the indicator of maximal mouth opening of the surgical treatment group was higher than that in the non-surgical treatment group (odds ratio [OR], 0.35; 95% confidence interval [CI], 0.21-0.50; P < 0.00001). After 1 year of follow-up, the malocclusion incidence in the surgical group was less than that in the non-surgical treatment group (OR, 0.29; 95% CI, 0.13-0.66; P = 0.003). The incidence of temporomandibular joint pain has no significant statistical difference in the 2 groups (OR, 0.76; 95% CI, 0.25-2.29; P = 0.63). No significant statistical difference in the indicators of facial symmetry (OR, 1.27; 95% CI, 0.34-4.79; P = 0.73) and mandibular activity status (OR, 0.94; 95% CI, 0.43-2.07; P = 0.88) has been found in the 2 groups. CONCLUSIONS: Surgical treatment has significant advantages in improving the maximal mouth opening as well as the occlusional relationship and has no significant statistical difference in the occurrence of joint pain after treatment, facial symmetry, and mandibular activity status in the 2 groups. Surgical treatment is suggested for patients older than 16 years with low position of condylar fracture, severe displacement, dislocation, and malocclusion. Joint pain, mandibular activity, facial symmetry after treatment, and jaw development impact should not be used as the influencing factors for treatment methods selection.

Precisely targeted drug delivery by mesenchymal stem cells-based biomimetic liposomes to cerebral ischemia-reperfusion injured hemisphere.

The precise and targeted delivery of therapeutic agents to the lesion sites remains a major challenge in treating brain diseases represented by ischemic stroke. Herein, we modified liposomes with mesenchymal stem cells (MSC) membrane to construct biomimetic liposomes, termed MSCsome. MSCsome (115.99 ± 4.03 nm) exhibited concentrated accumulation in the cerebral infarcted hemisphere of mice with cerebral ischemia-reperfusion injury, while showing uniform distribution in the two cerebral hemispheres of normal mice. Moreover, MSCsome exhibited high colocalization with damaged nerve cells in the infarcted hemisphere, highlighting its advantageous precise targeting capabilities over liposomes at both the tissue and cellular levels. Leveraging its superior targeting properties, MSCsome effectively delivered Dl-3-n-butylphthalide (NBP) to the injured hemisphere, making a single-dose (15 mg/kg) intravenous injection of NBP-encapsulated MSCsome facilitate the recovery of motor functions in model mice by improving the damaged microenvironment and suppressing neuroinflammation. This study underscores that the modification of the MSC membrane notably enhances the capacity of liposomes for precisely targeting the injured hemisphere, which is particularly crucial in treating cerebral ischemia-reperfusion injury.

Dental optical coherence tomography.

This review paper describes the applications of dental optical coherence tomography (OCT) in oral tissue images, caries, periodontal disease and oral cancer. The background of OCT, including basic theory, system setup, light sources, spatial resolution and system limitations, is provided. The comparisons between OCT and other clinical oral diagnostic methods are also discussed.

Microplastics affect arsenic bioavailability by altering gut microbiota and metabolites in a mouse model.

Microplastics exposure is a new human health crisis. Although progress in understanding health effects of microplastic exposure has been made, microplastic impacts on absorption of co-exposure toxic pollutants such as arsenic (As), i.e., oral bioavailability, remain unclear. Microplastic ingestion may interfere As biotransformation, gut microbiota, and/or gut metabolites, thereby affecting As oral bioavailability. Here, mice were exposed to arsenate (6 µg As g-1) alone and in combination with polyethylene particles of 30 and 200 µm (PE-30 and PE-200 having surface area of 2.17 × 103 and 3.23 × 102 cm2 g-1) in diet (2, 20, and 200 µg PE g-1) to determine the influence of microplastic co-ingestion on arsenic (As) oral bioavailability. By determining the percentage of cumulative As consumption recovered in urine of mice, As oral bioavailability increased significantly (P < 0.05) from 72.0 ± 5.41% to 89.7 ± 6.33% with PE-30 at 200 µg PE g-1 rather than with PE-200 at 2, 20, and 200 µg PE g-1 (58.5 ± 19.0%, 72.3 ± 6.28%, and 69.2 ± 17.8%). Both PE-30 and PE-200 exerted limited effects on pre- and post-absorption As biotransformation in intestinal content, intestine tissue, feces, and urine. They affected gut microbiota dose-dependently, with lower exposure concentrations having more pronounced effects. Consistent with the PE-30-specific As oral bioavailability increase, PE exposure significantly up-regulated gut metabolite expression, and PE-30 exerted greater effects than PE-200, suggesting that gut metabolite changes may contribute to As oral bioavailability increase. This was supported by 1.58-4.07-fold higher As solubility in the presence of up-regulated metabolites (e.g., amino acid derivatives, organic acids, and pyrimidines and purines) in the intestinal tract assessed by an in vitro assay. Our results suggested that microplastic exposure especially smaller particles may exacerbate the oral bioavailability of As, providing a new angle to understand health effects of microplastics.

Morphometric Changes of Osteocyte Lacunar in Diabetic Pig Mandibular Cancellous Bone.

Osteocytes play an important role in bone metabolism. The interactions of osteocytes with the surrounding microenvironment can alter cellular and lacunar morphological changes. However, objective quantification of osteocyte lacunae is challenging due to their deep location in the bone matrix. This project established a novel method for the analytical study of osteocytes/lacunae, which was then used to evaluate the osteocyte morphological changes in diabetic pig mandibular bone. Eight miniature pigs were sourced, and diabetes was randomly induced in four animals using streptozotocin (STZ) administration. The mandibular tissues were collected and processed. The jawbone density was evaluated with micro-CT. Osteocyte lacunae were effectively acquired and identified using backscattered electron scanning microscopy (BSE). A significantly decreased osteocyte lacunae size was found in the diabetic group. Using the acid etching method, it was demonstrated that the area of osteocyte and lacunae, and the pericellular areas were both significantly reduced in the diabetes group. In conclusion, a standard and relatively reliable method for analyzing osteocyte/lacunae morphological changes under compromised conditions has been successfully established. This method demonstrates that diabetes can significantly decrease osteocyte/lacunae size in a pig's mandibular cancellous bone.

CsHCT-Mediated Lignin Synthesis Pathway Involved in the Response of Tea Plants to Biotic and Abiotic Stresses.

Many studies have shown that phenolic compounds such as lignin and flavonoids enhance plant resistance. Tea plants are rich in flavonoid compounds. Whether these compounds are related to tea plant resistance is unclear. In this study, an interesting conclusion was drawn on the basis of experimental results: in response to abiotic stress (except for sucrose treatment), gene expression was increased in the phenylpropanoid and lignin pathways and was reduced in the flavonoid pathway in tea plants. CsHCTs, the genes located at the branch point of the lignin and flavonoid pathways, are most suitable for regulating the ratio of carbon flow in the lignin pathway and flavonoid synthesis. Enzymatic and genetic modification experiments proved that CsHCTs encode hydroxycinnamoyl-coenzyme A:shikimate/quinate hydroxycinnamoyl transferase in vitro and in vivo. Furthermore, the genetic modification results showed that the contents of phenolic acids and lignin were increased in tobacco and Arabidopsis plants overexpressing CsHCTs, whereas the content of flavonol glycosides was decreased. Both types of transgenic plants showed resistance to many abiotic stresses and bacterial infections. We speculate that CsHCTs participate in regulation of the metabolic flow of carbon from the flavonoid pathway to the chlorogenic acid, caffeoylshikimic acid, and lignin pathways to increase resistance to biotic and abiotic stresses.

Creation of Bony Microenvironment with Extracellular Matrix Doped-Bioactive Ceramics to Enhance Osteoblast Behavior and Delivery of Aspartic Acid-Modified BMP-2 Peptides.

INTRODUCTION: Decellularized matrix from porcine small intestinal submucosa (SIS) endows scaffolds with an ECM-like surface, which enhances stem cell self-renewal, proliferation, and differentiation. Mesoporous bioactive glass (MBG) is extensively recognized as an excellent bio-ceramic for fabricating bone grafts. MATERIALS AND METHODS: In the current study, SIS was doped on an MBG scaffold (MBG/SIS) using polyurethane foam templating and polydopamine chemistry method. To mimic the bony environment of a natural bone matrix, an ECM-inspired delivery system was constructed by coupling the BMP2-related peptide P28 to a heparinized MBG/SIS scaffold (MBG/SIS-H-P28). The release of P28 from MBG/SIS-H-P28 and its effects on the proliferation, viability, and osteogenic differentiation of bone marrow stromal stem cells were investigated in vitro and in vivo. RESULTS: Our research indicated that the novel tissue-derived ECM scaffold MBG/SIS has a hierarchical and interconnected porous architecture, and superior biomechanical properties. MBG/SIS-H-P28 released P28 in a controlled manner, with the long-term release time of 40 d. The results of in vitro experiments showed improvements in cell proliferation, cell viability, alkaline phosphatase activity, and mRNA expression levels of osteogenesis-related genes (Runx-2, OCN, OPN, and ALP) compared to those of MBG/SIS or MBG/SIS-P28 and MBG/SIS-H-P28. The in vivo results demonstrated that MBG/SIS-H-P28 scaffolds evidently increased bone formation in rat calvarial critical-sized defect compared to that in controls. CONCLUSION: MBG/SIS-H-P28 scaffolds show potential as ideal platforms for delivery of P28 and for providing a bony environment for bone regeneration.

[Mechanical properties of 3D-printed titanium mesh and its biocompatibility in vitro].

PURPOSE: To compare the mechanical properties of 3D-printed titanium meshes and pre-shaped titanium meshes, and to evaluate the effects of 3D-printed titanium meshes on cell proliferation and differentiation. METHODS: 3D- printed titanium meshes were produced and prepared with laser printing machine. The mechanical properties were analyzed by static tension and compression load test. Bone marrow mesenchymal stem cells (BMSCs) were extracted from 4-week-old male SD rats. BMSCs were co-cultured with 3D-printed titanium meshes of different apertures. Cell counting kit-8 (CCK-8) assay was used to detect cell proliferation. Alkaline phosphatase (ALP) activity assay was used to test ALP activity. The expression of related osteogenic genes was tested by real-time PCR. The adhesion and growth of BMSCs were investigated by scanning electron microscopy (SEM) and living / dead cell staining. SPSS 22.0 software package was used for statistical analysis of the results. RESULTS: The results of 3D-printing Ti-meshes tension and compression loading experiment were excellent. The 3D-printing Ti-meshes showed no inhibitory effects on cell proliferation, survival and adhesion, but had a positive effect on osteogenesis of BMSCs. CONCLUSIONS: The mechanical properties of 3D-printed Ti-meshes are excellent. The 3D-printed Ti-meshes have good biocompatibility.

[Application of near infrared spectroscopy in analysis of wood properties].

There is substantial interest in the improvement of wood properties through genetic selection or a change in silviculture prescription. Tree breeding purpose requires measurement of a large number of samples. However, traditional methods of assessing wood properties are both time consuming and destructive, limiting the numbers of samples that can be processed, so new method would be needed to find. Near infrared spectroscopy (NIR) is an advanced spectroscopic tool for nondestructive evaluation of wood and it can quickly, accurately estimate the properties of increment core, solid wood or wood meal. The present paper reviews the advances in the research on the wood chemistry properties and anatomical properties using NIR.

Variants in MME are associated with autosomal-recessive distal hereditary motor neuropathy.

OBJECTIVE: To identify a new genetic cause in patients segregating distal hereditary motor neuropathy (dHMN) with an autosomal recessive pattern. METHODS: Whole-exome sequencing was conducted in two siblings and was combined with segregation analysis. Additionally, 83 unrelated dHMN patients with unknown genetic cause were screened. RNA analysis was performed using blood lymphocytes and HEK293 cells transfected with mutant plasmids. Immunohistochemistry and Western blot analysis was applied to the nerve tissue. The enzymatic activities of mutant proteins were measured in the cultured cells to verify the pathogenicity of variants. RESULTS: The clinical features of the patients showed late-onset phenotype of distal motor neuropathy without sensory involvement. We identified that compound heterozygous variants of c.1342C>T and c.2071_2072delGCinsTT in the membrane metalloendopeptidase (MME) gene co-segregated with the phenotype in a dHMN family. In an additional group of 83 patients with dHMN, compound heterozygous variants of c.1416+2T>C and c.2027C>T in MME were identified in one patient. The splice site variant c.1416+2T>C results in skipping of exon 13. The stop variant c.1342C>T induces mRNA degradation via nonsense-mediated mRNA decay. Transcript levels of MME in the lymphocytes showed no significant differences between the patients and controls. We also identified that MME variants were associated with mild decrease in protein expression in the sural nerve and significant impairments of enzymatic activity. INTERPRETATION: Variants in the MME gene were associated with not only a Charcot-Marie-Tooth neuropathy phenotype but also with an autosomal-recessive dHMN phenotype. Loss of function may play a role in the pathogenesis of dHMN.

Composite Scaffolds of Mineralized Natural Extracellular Matrix on True Bone Ceramic Induce Bone Regeneration Through Smad1/5/8 and ERK1/2 Pathways.

A stem cell-derived mineralized extracellular matrix (ECM) may be a good strategy to endow scaffolds with a bone microenvironment, thus inducing bone regeneration. However, it also faces some challenges, such as limited number of cells, additional wound for autologous cell isolation, and time consumption of cell expansion. In this study, we designed a novel tissue-derived ECM scaffold fabricated by depositing porcine small intestinal submucosa (SIS) ECM on true bone ceramic (TBC), which was followed by mineralization treatment (mSIS/TBC). In vitro, compared with pure TBC, mSIS/TBC promoted cell proliferation, cell viability, and osteoblastic differentiation of the newly seeded rat bone marrow mesenchymal stem cells (BMSCs), and upregulation of the messenger RNA (mRNA) level of osteogenesis-related genes. Western blot assay revealed that mSIS/TBC enhanced osteoblastic differentiation through activation of phosphorylated Smad1/5/8 and phosphorylated extracellular signal-regulated kinase (ERK), as an underlying mechanism. In vivo, in a rat cranial critical size defect model, mSIS/TBC scaffolds induced greater bone formation than pure TBC scaffolds. Meanwhile, a comparative study on the capacity of bone regeneration was also carried out between mSIS/TBC and BMSC-derived ECM deposited on TBC scaffold in vivo and in vitro. The results demonstrated that mSIS/TBC scaffolds acquired a comparable bone regeneration efficacy to that of BMSC-derived ECM deposited on TBC scaffolds. Collectively, our results demonstrated that mSIS/TBC enhanced bone regeneration by supporting cell proliferation and cell viability, and by activating Smad1/5/8 and ERK1/2 signal pathways of BMSC in vitro and in vivo; thus, mSIS/TBC is an excellent alternative to stem cell-derived ECM scaffold for bone regeneration.

Guided osteoporotic bone regeneration with composite scaffolds of mineralized ECM/heparin membrane loaded with BMP2-related peptide.

INTRODUCTION: At present, the treatment of osteoporotic defects poses a great challenge to clinicians, owing to the lower regeneration capacity of the osteoporotic bone as compared with the normal bone. The guided bone regeneration (GBR) technology provides a promising strategy to cure osteoporotic defects using bioactive membranes. The decellularized matrix from the small intestinal submucosa (SIS) has gained popularity for its natural microenvironment, which induces cell response. MATERIALS AND METHODS: In this study, we developed heparinized mineralized SIS loaded with bone morphogenetic protein 2 (BMP2)-related peptide P28 (mSIS/P28) as a novel GBR membrane for guided osteoporotic bone regeneration. These mSIS/P28 membranes were obtained through the mineralization of SIS (mSIS), followed by P28 loading onto heparinized mSIS. The heparinized mSIS membrane was designed to improve the immobilization efficacy and facilitate controlled release of P28. P28 release from mSIS-heparin-P28 and its effects on the proliferation, viability, and osteogenic differentiation of bone marrow stromal stem cells from ovariectomized rats (rBMSCs-OVX) were investigated in vitro. Furthermore, a critical-sized OVX calvarial defect model was used to assess the bone regeneration capability of mSIS-heparin-P28 in vivo. RESULTS: In vitro results showed that P28 release from mSIS-heparin-P28 occurred in a controlled manner, with a long-term release time of 40 days. Moreover, mSIS-heparin-P28 promoted cell proliferation and viability, alkaline phosphatase activity, and mRNA expression of osteogenesis-related genes in rBMSCs-OVX without the addition of extra osteogenic components. In vivo experiments revealed that mSIS-heparin-P28 dramatically stimulated osteoporotic bone regeneration. CONCLUSION: The heparinized mSIS loaded with P28 may serve as a potential GBR membrane for repairing osteoporotic defects.

[Diagnosis and treatment of odontoid fracture combined with lower cervical spinal injury].

OBJECTIVE: To investigate the mechanism, clinical features and treatment of odontoid fracture combined with lower cervical spinal injury. METHODS: From January 1999 to December 2004, 57 cases of type II or shallow type III odontoid fractures were studied retrospectively. Six cases were found combined with lower cervical injury, the mean age was 54 years, and 4 of the 6 cases were complicated with cervical spondylarthrosis or ankylosing spondylitis. For the lower cervical injury, fracture-dislocation was found in 2 cases, the disruption of disc and ligament was found in 4 cases among which 2 cases were suffered from incomplete spinal cord injury; Both were caused by lower cervical spinal injury. All of the 6 cases were performed with surgery in odontoid fracture and lower cervical spinal injury simultaneously; Lower cervical spinal injuries were stabilized firstly in 2 cases, which responsible for neurological involvement; For the other 4 cases without neurological involvement, stabilization was performed in odontoid fracture firstly in 2 cases, due to inability to achieve reduction of odontoid fracture preoperatively, however, for the another 2 cases with anatomic reduction of the odontoid fracture preoperatively, lower cervical injuries were stabilized firstly. RESULTS: After an average follow-up of 10 months, all cases were obtained solid fusion both in odontoid fracture and lower cervical spinal injury, and without the complications associated with operation and prolonged bed rest. Two cases with neurological defect improved 1 scale in Frankel score. CONCLUSIONS: The incidence of odontoid fracture combined with lower cervical spinal injury is about 10.5% of the odontoid fracture, and it is vulnerable in the elderly patient with cervical spondylarthrosis. MRI should be used routinely for accurate diagnosis. Surgical stabilization is the choice of treatment due to facilitating early rehabilitation and reducing the complications. The surgical schedule is planned according to the fact of neurological involvement and the extent of stability between the odontoid fracture and lower cervical spinal injury.

A shocking craniofacial penetrating injury by a steel bar.

Owing to the diversity in cause and damage, there is no standard surgical treatment method for a complicated penetrating craniofacial injury. The treatment of a complicated penetrating head injury caused by a steel bar is presented here. A 66-year-old woman fell onto a steel bar at a construction site and it penetrated the mandible, entered the sinus and orbital cavities, and reached the base of the frontal bone. A multi-disciplinary team including a neurosurgeon, otolaryngologist, and plastic surgeon was involved in removing the steel bar. The patient survived without sequelae except for blindness in the right eye. Despite the lack of standardized surgical treatment for a complicated penetrating craniofacial injury, aggressive treatment by a multidisciplinary team can result in good outcomes.