Region-specific sympatho-adrenergic regulation of specialized vasculature in bone homeostasis and regeneration.

Type H vessels couple angiogenesis with osteogenesis, while sympathetic cues regulate vascular and skeletal function. The crosstalk between sympathetic nerves and type H vessels in bone remains unclear. Here, we first identify close spatial connections between sympathetic nerves and type H vessels in bone, particularly in metaphysis. Sympathoexcitation, mimicked by isoproterenol (ISO) injection, reduces type H vessels and bone mass. Conversely, beta-2-adrenergic receptor (ADRB2) deficiency maintains type H vessels and bone mass in the physiological condition. In vitro experiments reveal indirect sympathetic modulation of angiogenesis via paracrine effects of mesenchymal stem cells (MSCs), which alter the transcription of multiple angiogenic genes in endothelial cells (ECs). Furthermore, Notch signaling in ECs underlies sympathoexcitation-regulated type H vessel formation, impacting osteogenesis and bone mass. Finally, propranolol (PRO) inhibits beta-adrenergic activity and protects type H vessels and bone mass against estrogen deficiency. These findings unravel the specialized neurovascular coupling in bone homeostasis and regeneration.

Engineered Chimeric Peptides with IGF-1 and Titanium-Binding Functions to Enhance Osteogenic Differentiation In Vitro under T2DM Condition.

Due to the complexity of the biomolecules and titanium (Ti) combination, it is a challenge to modify the implant surface with biological cytokines. The study proposed a new method for immobilizing cytokines on implant surface to solve the problem of low osseointegration under type 2 diabetes mellitus (T2DM) condition. This new modified protein that connected Ti-binding artificial aptamer minTBP-1 with Insulin-like growth factor I (IGF-I), had a special strong affinity with Ti and a therapeutic effect on diabetic bone loss. According to the copies of minTBP-1, three proteins were prepared, namely minTBP-1-IGF-1, 2minTBP-1-IGF-1 and 3minTBP-1-IGF-1. Compared with the other modified proteins, 3minTBP-1-IGF-1 adsorbed most on the Ti surface. Additionally, this biointerface demonstrated the most uniform state and the strongest hydrophilicity. In vitro results showed that the 3minTBP-1-IGF-1 significantly increased the adhesion, proliferation, and mineralization activity of osteoblasts under T2DM conditions when compared with the control group and the other modified IGF-1s groups. Real-time PCR assay results confirmed that 3minTBP-1-IGF-1 could effectively promote the expression of osteogenic genes, that is, ALP, BMP-2, OCN, OPG, and Runx2. All these data indicated that the 3minTBP-1-IGF-1 had the most efficacious effect in promoting osteoblasts osteogenesis in diabetic conditions, and may be a promising option for further clinical use.

Activation of the Mesencephalic Trigeminal Nucleus Contributes to Masseter Hyperactivity Induced by Chronic Restraint Stress.

Psychological stress is commonly accepted to be closely associated with masticatory muscle disorder, which is the main symptom of temporomandibular disorder (TMD). Previous studies have confirmed that exposure to stress may cause masticatory muscle hyperactivity. However, the central mechanism underlying this process remains unclear. The mesencephalic trigeminal nucleus (Vme), which resides in the brainstem, is the primary afferent center for masticatory proprioception and plays a key role in oral-motor movements by projecting to the trigeminal motor nucleus (Vmo). Therefore, the present study was designed to examine the role of Vme neurons in masseter overactivity induced by chronic stress. We found that subjecting mice to restraint stress (6 h/day) for 14 days caused significant anxiety-like behavior, obvious masseter overactivity, and markedly enhanced electrophysiological excitability of Vme neurons. By using anterograde tract tracing combined with immunofluorescence staining methods, we observed vesicular glutamate transporter 1 (VGLUT1)-positive glutamatergic projections from the Vme to the Vmo. Moreover, chronic restraint stress (CRS) elevated the expression of VGLUT1 and choline acetyltransferase (ChAT) in Vmo. Furthermore, administration of VGLUT1-targeted short hairpin RNA (shRNA) into the bilateral Vme significantly suppressed the enhanced overexcitability of Vme neurons, downregulated the overexpression of VGLUT1 and ChAT in the Vmo, and attenuated the elevated overactivity of the masseter caused by CRS. Taken together, we showed that CRS can excite neurons in the Vme, enhancing glutamatergic excitatory projections from the Vme to the Vmo and resulting in masseter muscle overactivity. These findings provide us with a novel central mechanism underlying the correlation between psychological factors and TMD.

Curcumin plays a local anti-inflammatory and antioxidant role via the HMGB1/TLR4/NF-ΚB pathway in rat masseter muscle under psychological stress.

BACKGROUND AND OBJECTIVE: Psychological stress causes structural and metabolic dysfunction of masseter muscles. The anti-inflammatory and anti-oxidative polyphenol curcumin plays a local antioxidant role in rat masseter muscles under psychological stress by an as-yet-unknown mechanism. The present study aimed to assess curcumin anti-inflammatory and anti-oxidative effects on masseter muscle and its possible molecular mechanisms. METHODS: We constructed a rat model of chronic unpredictable moderate stress (CUMS). Psychological stress was assessed by determining the levels of adrenocorticotropic hormone (ACTH) and cortisol in serum. Enzyme-linked immunosorbent assays measured inflammatory cytokines and markers of oxidative stress in masseter muscles. Levels of high-mobility group box 1 (HMGB1), interleukin (IL)-1ß, IL-6 and tumour necrosis factor-alpha (TNF-α) were determined using quantitative PCR analyses and immunofluorescent staining. Toll-like receptor 4 (TLR4) and nuclear factor kappa B (NF-κB) activation were examined using western blotting. RESULTS: The CUMS group showed increased serum cortisol and ACTH levels. Pathological changes in the ultrastructure, oxidative stress and inflammatory cytokines in the masseter muscles were also observed. Curcumin treatment (50, 100 mg/kg) ameliorated these changes significantly by varying degrees. Mechanistically, increased levels of phosphorylated NF-κB, toll-like receptor 4 and HMGB1 were observed, which were also ameliorated by curcumin treatment. CONCLUSION: Curcumin can reduce local pathological changes, levels of oxidative stress and inflammatory factors in masseter muscles. Psychological stress activates HMGB1 expression and increases the expression of downstream TLR4 and p-NF-κB, which could be reduced by curcumin. Thus, curcumin might exert anti-inflammatory and antioxidant effects in masseter muscles via the HMGB1/TLR4/NF-κB pathway.

Genetic Diversity Evaluation and Conservation of Topmouth Culter (Culter alburnus) Germplasm in Five River Basins in China.

To study the genetic diversity of Culter alburnus (C. alburnus) populations, we analyzed the genetic diversity of five C. alburnus populations from Songhua Lake (SH), Huaihe River (HH), Changjiang River (CJ), Taihu Lake (TH), and Gehu Lake (GH) based on mitochondrial COI gene sequences. The results showed that the average contents of bases T, C, A, and G in the 526 bp COI gene sequence were 25.3%, 18.1%, 28.1%, and 28.6%, respectively, which showed AT bias. A total of 115 polymorphic sites were detected in the five populations, and 11 haplotypes (Hap) were defined. The nucleotide diversity (Pi) of the five populations ranged from 0.00053 to 0.01834, and the haplotype diversity (Hd) ranged from 0.280 to 0.746, with the highest genetic diversity in the TH population, followed by the SH population, with lower genetic diversity in the HH, CJ and GH populations. The analysis of the fixation index (Fst) and the genetic distance between populations showed that there was significant genetic differentiation between the SH population and the other populations, and the genetic distances between all of them were far; the genetic diversity within populations was higher than that between populations. Neutral tests, mismatch distributions, and Bayesian skyline plot (BSP) analyses showed that the C. alburnus populations have not experienced population expansion and are relatively stable in historical dynamics.

Utility of multiple endoscopic techniques in differential diagnosis of gallbladder adenomyomatosis from gallbladder malignancy with bile duct invasion: A case report.

BACKGROUND: Gallbladder adenomyomatosis (GAM) is a benign lesion, characterized by thickening of the gallbladder wall and a focal mass, which overlap with the features of gallbladder malignancy. Consequently, differential diagnosis of GAM from gallbladder cancer is difficult and approximately 20% of suspected malignant biliary strictures are postoperatively confirmed as benign lesions. Herein, we report a case in which a preoperative diagnosis of GAM was made by a combination of endoscopic and imaging techniques. CASE SUMMARY: A 40-year-old man was referred to our hospital chiefly for a fever and right upper abdominal pain with dark urine. Enhanced computed tomography showed thickening of the gallbladder wall and a mass in the gallbladder neck with involvement of the hepatic bile ducts, which was suspected to be malignant. Gallbladder malignancy with bile duct invasion was ruled out by subsequent endoscopic examinations, including endoscopic retrograde cholangio-pancreatography, intraductal ultrasound, and SpyGlass. Endoscopic examinations showed a homogeneous hyperechoic lesion with smooth margins of benign bile duct stricture suggestive of inflammatory stenosis of the bile duct. The patient underwent laparoscopic cholecystectomy. GAM was postoperatively diagnosed and confirmed based on the histopathology results, which are consistent with the preoperative diagnosis. Notably, no malignant event occurred in the patient during a 12-mo follow-up period. CONCLUSION: A combination of endoscopic techniques may help in the differential diagnosis of GAM from gallbladder cancer.

What are the important outcomes in traumatic dental injuries? An international approach to the development of a core outcome set.

BACKGROUND/AIMS: There are numerous treatment options following traumatic dental injury (TDI). Systematic reviews of different treatments are challenging owing to the diversity of outcomes reported between clinical studies. This issue could be addressed through the development and implementation of a agreed and standardized collection of outcomes known as a core outcome set (COS). The aim of this study was to develop a COS for TDI in children and adults. The secondary aim was to establish what, how, when and by whom these outcomes should be measured. MATERIALS AND METHOD: The project was registered with Core Outcomes Measures in Effectiveness Trials (COMET). A web-based survey was developed to capture the opinions of dentists globally as to which outcomes should be recorded. A list of outcomes was entered into a Delphi Survey and scored by an Expert Working Group (EWG). The scoring was repeated, followed by conference calls to discuss, refine and finalize the COS. The EWG split into small groups of subject-specific experts to determine how, when and by whom each outcome would be measured. RESULTS: The questionnaire was completed by 1476 dentists. The EWG identified 13 core outcomes to be recorded for all TDI's. An additional 10 injury-specific outcomes were identified. A table has been produced for each outcome detailing what, when, and how each outcome should be recorded. CONCLUSIONS: A robust consensus process was used to develop an international COS for TDI in children and adults. This includes both generic and injury-specific outcomes across all identified domains.

Psychological Stress Alters Extracellular Matrix Metabolism in Mandibular Condylar Cartilage.

OBJECTIVE: To explore the effect of long-term stress on the temporomandibular joint (TMJ) condyle and its possible underlying mechanism. METHODS: A 12-week, chronic unpredictable mild stress (CUMS) model was used to induce long-term psychological stress in rats. Rats were randomly divided into control group (CONT), chronic unpredictable mild stress group (CUMS) and chronic unpredictable mild stress with fluoxetine treatment group (CUMS + DT) (n = 30 per group). A 5 mg/kg dose of fluoxetine was intraperitoneally injected daily 0.5 h before stress. A sucrose preference test, plasma corticosterone test and open-field test were performed to verify the feasibility of the CUMS model. Histopathology was used to observe the pathological changes of condyle. The expression levels of inflammatory cytokines, matrix metalloproteases (MMPs) and extracellular matrix (ECM) were measured by real-time polymerase chain reaction, western blotting and immunohistochemistry. RESULTS: At 8 and 12 weeks after exposure to CUMS, the rats showed higher plasma corticosterone than the control rats. Additionally, for the open-field test, the rats exposed to CUMS spent more time in the centre zone and moved a shorter distance than the control and drug treatment rats. In addition, pathological changes in the condylar cartilage occurred in the 8-week CUMS subgroup and were more obvious in the 12-week CUMS subgroup. The CUMS caused an increase in the secretion of inflammatory cytokines, imbalanced expression of MMPs and tissue inhibitor of metalloproteinase-1 and accelerated degradation of ECM in condylar cartilage in a time-dependent manner. CONCLUSION: Osteoarthritis-like lesions can be caused by long-term CUMS in the mandibular condyles, which suggests that the imbalance in chondrocyte-secreted regulatory factors within the cartilage of the TMJ may play an important role in cartilage injury induced by psychological stress.

The Distinct Effects of Estrogen and Hydrostatic Pressure on Mesenchymal Stem Cells Differentiation: Involvement of Estrogen Receptor Signaling.

This study aimed to investigate the differential and synergistic effects of mechanical stimulation and estrogen on the proliferation and osteogenic or chondrogenic differentiation potential of bone marrow mesenchymal stem cells (BMSCs) and the roles of estrogen receptor (ER) in them. BMSCs were isolated and cultured using the whole bone marrow adherence method, and flow cytometry was used to identify the surface marker molecules of BMSCs. Cells were pre-treated with 1 nM 17ß-estradiol or 1 nM of the estrogen receptor antagonist tamoxifen. Then, the cells were stimulated with hydrostatic pressure. Assessment included flow cytometry analysis of the cell cycle; immunofluorescent staining for F-actin; protein quantification for MAPK protein; and mRNA analysis for Col I, OCN, OPN and BSP after osteogenic induction and Sox-9, Aggrecan and Col-II after chondrogenic induction. Hydrostatic pressure (90 kPa/1 h) and 1 nM 17ß-estradiol enhanced the cellular proliferation ability and the cytoskeleton activity but without synergistic biological effects. Estrogen activated ERKs and JNKs simultaneously and promoted the osteogenic differentiation, whereas the pressure just caused JNK-1/2 activation and promoted the chondrogenic differentiation of BMSCs. Estrogen had antagonism effect on chondrogenic promotion of hydrostatic pressure. Mechanobiological effects of hydrostatic pressure are closely associated with ERα activity. MAPK molecules and F-actin were likely to be important mediator molecules in the ER-mediated mechanotransduction of BMSCs.

Vacancy Structures and Melting Behavior in Rock-Salt GeSbTe.

Ge-Sb-Te alloys have been widely used in optical/electrical memory storage. Because of the extremely fast crystalline-amorphous transition, they are also expected to play a vital role in next generation nonvolatile microelectronic memory devices. However, the distribution and structural properties of vacancies have been one of the key issues in determining the speed of melting (or amorphization), phase-stability, and heat-dissipation of rock-salt GeSbTe, which is crucial for its technological breakthrough in memory devices. Using spherical aberration-aberration corrected scanning transmission electron microscopy and atomic scale energy-dispersive X-ray mapping, we observe a new rock-salt structure with high-degree vacancy ordering (or layered-like ordering) at an elevated temperature, which is a result of phase transition from the rock-salt phase with randomly distributed vacancies. First-principles calculations reveal that the phase transition is an energetically favored process. Moreover, molecular dynamics studies suggest that the melting of the cubic rock-salt phases is initiated at the vacancies, which propagate to nearby regions. The observation of multi-rock-salt phases suggests another route for multi-level data storage using GeSbTe.

Effects of occlusion on mandibular morphology and architecture in rats.

BACKGROUND: A rodent occlusal hypofunction model has been widely established in jawbone-related studies. However, the effects of occlusal stimuli, with total elimination of molar contacts, and its rehabilitation on mandibular remodeling remain unclear. MATERIALS AND METHODS: Forty-eight 5-wk-old Sprague-Dawley male rats were used. Twenty-four experimental rats underwent occlusal hypofunction by insertion of a bite-raising appliance. Twenty-four rats received no treatment (control group). Two weeks later, half the experimental rats (occlusal hypofunction group) were killed; the appliance was removed from the remaining experimental rats (recovery group) for two additional weeks before killing. Control animals were killed biweekly. Body weight and masseter muscle weight were measured, and the mandibles were subjected to micro-computed tomography to evaluate the mandibular morphology and cortical bone characteristics. The expressions of osteoblast- and osteoclast-related genes were evaluated with quantitative polymerase chain reaction. RESULTS: No significant body weight differences were observed between the experimental and control rats. However, lighter masseter muscle, shorter mandibular incisor crown, mandibular body and ramus, and higher mandibular alveolar process and first molar fossae were observed in the occlusal hypofunction group. Moreover, the cortical bone characteristics associated with the expression of osteoblast- and osteoclast-related genes were remarkably different in the central and posterior mandible in the occlusal hypofunction group. At the 2-wk recovery time point after occlusal stimuli, the altered parameters in the masseter and mandible returned to normal levels. CONCLUSIONS: Mandibular remodeling via bone turnover is region specific for altered occlusal stimuli. Normal occlusion is an important determinant of the mandibular morphology and architecture.

Activation of satellite glial cells in the trigeminal ganglion contributes to masseter mechanical allodynia induced by restraint stress in rats.

It is commonly accepted that psychological stress contributes to the development of chronic orofacial pain. However, the neural mechanism underlying this process has remained unclear. The present study was performed to determine the involvement of satellite glia cells (SGCs) in the trigeminal ganglion (TG) in stress-induced increases in masseter muscle allodynia in rats. Using a chronic restraint stress model, we found that exposure to a 14-day stress but not a 3-day stress (6 h/day) caused decreased body weight gain, behavioral changes and marked masseter allodynia in rats. SGCs were dramatically activated, and substance P (SP) expression was significantly increased in the TG. A further analysis was undertaken to investigate the contribution of SGCs; the expression of interleukin-1ß (IL-1ß) in SGCs and interleukin-1 receptor I (IL-1RI) in neurons was significantly increased after chronic restraint stress, whereas injection of L-α-aminoadipate (a SGC inhibitor, LAA) into the TG dramatically inhibited the overexpression of these proteins. In addition, LAA or interleukin-1 receptor antagonist (IL-1ra) administration into the TG could significantly attenuate the mechanical masseter allodynia and overexpression of SP in the TG induced by restraint stress. These results suggest that SGC activation in the TG may play a role in masseter allodynia induced by restraint stress. The over-release of IL-1ß and excessive IL1-RI expressions have close relationship with the stress induced masseter allodynia.

Potential dental pulp revascularization and odonto-/osteogenic capacity of a novel transplant combined with dental pulp stem cells and platelet-rich fibrin.

Our aim is to investigate the cytobiological effects of autologous platelet-rich fibrin (PRF) on dental pulp stem cells (DPSCs) and to explore the ectopic and orthotopic possibilities of dental pulp revascularization and pulp-dentin complex regeneration along the root canal cavities of the tooth by using a novel tissue-engineered transplant composed of cell-sheet fragments of DPSCs and PRF granules. Canine DPSCs were isolated and characterized by assaying their colony-forming ability and by determining their cell surface markers and osteogenic/adipogenic differentiation potential. The biological effects of autologous PRF on DPSCs, including cell proliferation, alkaline phosphatase (ALP) activity and odonto-/osteogenic gene expression, were then investigated and quantified. A novel transplant consisting of cell-sheet fragments of DPSCs and PRF granules was adopted to regenerate pulp-dentin-like tissues in the root canal, both subcutaneously in nude mice and in the roots of canines. PRF promoted the proliferation of DPSCs in a dose- and time-dependent manner and induced the differentiation of DPSCs to odonto-/osteoblastic fates by increasing the expression of the Alp, Dspp, Dmp1 and Bsp genes. Transplantation of the DPSC/PRF construct led both to a favorable regeneration of homogeneous and compact pulp-like tissues with abundantly distributed blood capillaries and to the deposition of regenerated dentin along the intracanal walls at 8 weeks post-operation. Thus, the application of DPSC/PRF tissue constructs might serve as a potential therapy in regenerative endodontics for pulp revitalization or revascularization.

Hydrostatic pressure promotes the proliferation and osteogenic/chondrogenic differentiation of mesenchymal stem cells: The roles of RhoA and Rac1.

Our previous studies have shown that hydrostatic pressure can serve as an active regulator for bone marrow mesenchymal stem cells (BMSCs). The current work further investigates the roles of cytoskeletal regulatory proteins Ras homolog gene family member A (RhoA) and Ras-related C3 botulinum toxin substrate 1 (Rac1) in hydrostatic pressure-related effects on BMSCs. Flow cytometry assays showed that the hydrostatic pressure promoted cell cycle initiation in a RhoA- and Rac1-dependent manner. Furthermore, fluorescence assays confirmed that RhoA played a positive and Rac1 displayed a negative role in the hydrostatic pressure-induced F-actin stress fiber assembly. Western blots suggested that RhoA and Rac1 play central roles in the pressure-inhibited ERK phosphorylation, and Rac1 but not RhoA was involved in the pressure-promoted JNK phosphorylation. Finally, real-time polymerase chain reaction (PCR) experiments showed that pressure promoted the expression of osteogenic marker genes in BMSCs at an early stage of osteogenic differentiation through the up-regulation of RhoA activity. Additionally, the PCR results showed that pressure enhanced the expression of chondrogenic marker genes in BMSCs during chondrogenic differentiation via the up-regulation of Rac1 activity. Collectively, our results suggested that RhoA and Rac1 are critical to the pressure-induced proliferation and differentiation, the stress fiber assembly, and MAPK activation in BMSCs.

Involvement of trigeminal astrocyte activation in masseter hyperalgesia under stress.

It is commonly accepted that psychological stress contributes to the development of temporomandibular joint disorders, in which chronic orofacial pain is the main symptom. However, the central mechanism underlying the development of these disorders has remained unclear. The current study was performed to determine the involvement of the glia in the trigeminal spinal subnucleus caudalis in stress-induced increases in masseter muscle hyperalgesia in rats. After being subjected to chronic restraint stress, the animals showed decreased body weight gain, behavioral changes and marked masseter allodynia. We also found that astrocytes, but not microglia, in the trigeminal subnucleus caudalis (Vc) were dramatically activated. A further analysis was undertaken to investigate the contribution of the glia; we intrathecally injected l-α-aminoadipate (astrocyte-specific inhibitor) and/or minocycline (microglia-specific inhibitor) into the stressed rats. Our results showed that l-α-aminoadipate (LAA), but not minocycline, could significantly attenuate the mechanical masseter allodynia and behavioral changes induced by restraint stress. In addition, the expression of interleukin-1ß (IL-1ß) and phosphorylated N-methyl-d-aspartic acid receptor 1 (p-NR1) in the Vc was significantly increased after chronic restraint stress, whereas LAA dramatically inhibited the overexpression of IL-1ß and p-NR1. Taken together, these results suggest that activated astrocytes in the Vc may be one of the most important factors in the pathophysiology of masseter hyperalgesia induced by restraint stress and the following overexpression of IL-1ß and excessive NMDAR phosphorylation may ultimately contribute to masseter hyperalgesia. Thus, inhibiting spinal astrocytic activation may represent a novel therapeutic strategy for the treatment of orofacial pain induced by stress.

[JAK2V617F mutation and TNF-α expression in myeloproliferative neoplasms and their correlation].

This study was aimed to explore the JAK2V617F mutation and TNF-α expression in patients with myeloproliferative neoplasm (MPN), and the relation between them so as to provide theoretical basis for clinical practice and target therapy. Sixty-two confirmed BCR-ABL-negative MPN patients and 15 healthy adults were enrolled in this study. The peripheral blood mononuclear cells of the patients and healthy controls were divided into two parts, one part was used to extract DNA, the other one was used to extract mRNA and reverse-transcribe into cDNA. Real-time fluorescent quantitative PCR was used to detect JAK2V617F mutation proportion and the expression level of TNF-α. The results showed that the positive rate of JAK2V617F mutation in MPN patients was 64.52% (40/62) , including 54.28% in essential thrombocythemia (ET) patients (19/35), 94.74% in polycythemia vera (PV) patients (18/19) and 37.50% in myelofibrosis (MF) (3/8) patients. Mutation proportions of JAK2V617F in ET, PV and MF patients were 0.838 ± 0.419, 4.417 ± 0.658, 2.746 ± 2.009 respectively. The expression of TNF-α in ET, PV and MF patients were higher than that in healthy controls: 1.7, 7.0, 8.2-fold (P < 0.05) respectively. In addition, TNF-α expression was correlated with JAK2V617F allele burden (Pearson r = 0.610,R(2) = 0.372,P = 0.005). It is concluded that TNF-α plays an important role in the pathogenesis of MPN, the TNF-α expression increases and is different in ET,PV and MF patients,which correlates with JAK2V617F allele burden.

Lamotrigine reverses masseter overactivity caused by stress maybe via Glu suppression.

Experimental and non-experimental stress significantly increase masseter muscle tone, which has been linked to the symptoms and pathogenesis of several stomatognathic system diseases. Until now, the mechanism underlying this phenomenon has remained unclear. The current study was performed to determine the mechanism of the stress-induced increase in masseter muscle tone and to investigate the effect of lamotrigine on this change. Animals challenged by repeated restraint stress received either saline as a vehicle or lamotrigine in doses of 20, 30 or 40 mg/kg body weight, whereas control animals received saline without stress treatment. Masseter muscle tone was assessed using electromyography. The activity of glutamate-related metabolic enzymes (glutaminase and glutamine synthetase) in the trigeminal motor nucleus was also investigated. Our results showed an interesting phenomenon: masseter muscle activity increased concurrently with the upregulation of the glutamate concentration after stress treatment. The activities of glutaminase and glutamine synthetase in the trigeminal motor nucleus were also upregulated and downregulated, respectively, when the rats were challenged by prolonged stress. The animals treated with lamotrigine at moderate and high doses had significantly decreased masseter muscle tone compared with stressed animals treated with vehicle. These results suggested that increased glutaminase activity and decreased glutamine synthetase activity increased glutamate production and decreased glutamate decomposition, causing an increase in glutamate levels in the trigeminal motor nucleus and eventually increasing masseter muscle tone. The administration of lamotrigine at doses of 30 or 40 mg/kg body weight effectively mitigated the adverse effects of stress on masseter muscle tone via inhibition of glutamate release.

Long-term curcumin treatment antagonizes masseter muscle alterations induced by chronic unpredictable mild stress in rats.

OBJECTIVE: To investigate the correlation between psychological stress and masseter muscle (MM) alterations, and explore the therapeutic agents for restoring the impaired masticatory muscle. DESIGN: We established a chronic unpredictable mild stress (CUMS) animal model and observed the changes of ultrastructure, redox homeostasis and energy metabolism in MM in rats with and without curcumin treatment. RESULTS: The depressive-like behavior in stressed rats was confirmed by the evidences of altered behaviors in sucrose preference test and open field test; while these phenomena were eased by curcumin. Except for the pathological changes in ultrastructure, decreased SOD, GSH-Px, CAT, Na(+)-K(+)ATPase, and Ca(2+)-Mg(2+)ATPase activities as well as increased MDA and LD content and LDH activity were also observed in MM in stressed rats. However, curcumin was capable of reversing CUMS-induced MM disorder by improving the activities of the examined anti-oxidant enzymes and energy metabolism enzymes. Additionally, the increased MDA content, LD content, and LDH activity in stressed rats were reduced by curcumin. CONCLUSION: All the findings indicate the adverse effects of CUMS on MM function in rats, and raise the possibility of developing curcumin as a potential therapeutic agent for psychological stress-induced masseter dysfunction.

Development of a system to monitor laryngeal movement during swallowing using a bend sensor.

BACKGROUND: Swallowing dysfunction (also known as dysphagia), which results in a deterioration of nutritional intake, slows rehabilitation and causes aspiration pneumonia, is very common following neurological impairments. Although videofluorographic (VF) examination is widely used for detecting aspiration, an objective and non-invasive method for assessing swallowing function has yet to be established because of a lack of adequate devices and protocols. In this paper, a bend sensor whose resistance is altered by bending was introduced to monitor swallowing-related laryngeal movement. METHODS: Six healthy male volunteers were recruited in the present study. Specific time points on the signal waveform produced by the bend sensor were defined to describe laryngeal movement by differential analysis. Additionally, the physiological significance of the obtained waveform was confirmed by analyzing the sequential correlations between the signal waveform from the bend sensor and hyoid bone kinetics simultaneously recorded by VF. RESULTS: Seven time points were successfully defined on the signal waveform to reference laryngeal movement. Each time point was well correlated with certain VF events, with evidence of no significant time lags, and there were positive correlations between waveform time points and matched VF events. Furthermore, obvious similarities were noticed between the duration of each phase on the signal waveform and the duration of the matched hyoid bone activity. CONCLUSIONS: The present monitoring system using a bend sensor might be useful for observing the temporal aspects of laryngeal movement during swallowing, and it was well coordinated with hyoid bone movement.

[Protective effect of shenfu injection pretreatment on brain of patients receiving aortic valve replacement undergoing cardiopulmonary bypass].

OBJECTIVE: To observe the protective effect of Shenfu Injection (SFI) pretreatment on brain of patients receiving aortic valve replacement (AVR) undergoing cardiopulmonary bypass (CPB). METHODS: Thirty AVR patients undergoing CPB were randomly assigned to 2 groups, the control group and the experimental group, 15 cases in each group. SFI at 1.5 mL/kg (dissolved in 250 mL 5% glucose solution) was intravenously dripped to those in the experimental group 5 days before operation, once daily for 5 successive days. SFI at 1.5 mL/kg (dissolved in 250 mL 5% glucose solution) was intravenously dripped to those 30 min before anesthesia induction. Equal dose of normal saline was intravenously dripped to those in the control group, and the other procedures were the same as those for patients in the experimental group. The venous blood sample (2 mL) was drawn from the right internal carotid vein immediately after induction of anesthesia (T1),10 min after CPB (T2), 30 min after GPB (T3), 2 h after CPB (T4), 24 h after CPB (T5), and 48 h after CPB (T6), thus detecting the plasma levels of S100beta and neuron specific enolase (NSE). And patients' cognitive function was assessed with mini-mental state examination (MMSE) scale on the day before operation, the 2nd and the 7th day after operation. RESULTS: There was no statistical difference in the levels of S1001 and NSE between the two groups at T1 (P > 0.05). There was statistical difference in the levels of S100beta and NSE between the two groups at T2, T3, T4, T5, T6, when compared with those at T1 (P <0.05). Besides, the levels of S100beta and NSE at T2, T3, T4, T5, T6 were lower in the experimental group than in the control group, showing statistical difference (P <0.05). The MMSE scores decreased on the 2nd day after operation in the two groups, showing statistical difference when compared with those on the day before operation (P <0.05). It was lowered more obviously in the control group. There was no statistical difference in the MMSE score between the 7th day post-operation and the day before operation (P >0.05). CONCLUSION: SFI pretreatment had protective effect on brain in AVR patients undergoing CPB.