Relationship between masseter muscle activity during wakefulness and temporomandibular disorder-related symptoms

BACKGROUND

Masseter muscle activity during wakefulness may be associated with temporomandibular disorder (TMD)-related symptoms, psychosocial status and pain-related disability; however, this relationship is unclear.

OBJECTIVES

This study aimed to determine the relationship between masseter muscle electromyography (EMG) burst/duration during wakefulness and TMD-related symptoms, psychosocial status and pain-related disability.

METHODS

Sixty participants were assessed masseter muscle activity during wakefulness using a data-logger-type ultraminiature EMG system and TMD-related symptoms, psychosocial status and pain-related disability through Axis I and II of the diagnostic criteria for TMD (DC/TMD). EMG bursts lasting longer than 0.25 s but less than 2.0 s and those lasting longer than 2.0 s were classified as phasic and tonic bursts, respectively.

RESULTS

Participants with palpation-related pain in the temporalis and masseter muscles, as assessed through the DC/TMD examination form in Axis I, had more bursts (number/h) (p = .035 and p = .009, respectively) and longer duration (time/h) (p = .013 and p = .004, respectively) of tonic bursts of the masseter muscle during wakefulness. Participants with palpation-related pain in the masseter muscles had higher oral behaviour scores during wakefulness using Axis II (p = .001), which affected the number and duration of tonic bursts of the masseter muscle activity during wakefulness (p = .011 and p = .007, respectively).

CONCLUSION

As tonic bursts mainly reflect clenching, individuals with pain in the masseter muscles by palpation may have a high frequency and longer duration of clenching, as well as a high frequency of oral behaviours during wakefulness.

Type I Interferon Delivery by iPSC-Derived Myeloid Cells Elicits Antitumor Immunity via XCR1+ Dendritic Cells

Type I interferons (IFNs) play important roles in antitumor immunity. We generated IFN-α-producing cells by genetically engineered induced pluripotent stem cell (iPSC)-derived proliferating myeloid cells (iPSC-pMCs). Local administration of IFN-α-producing iPSC-pMCs (IFN-α-iPSC-pMCs) alters the tumor microenvironment and propagates the molecular signature associated with type I IFN. The gene-modified cell actively influences host XCR1⁺ dendritic cells to enhance CD8⁺ T cell priming, resulting in CXCR3-dependent and STING-IRF3 pathway-independent systemic tumor control. Administration of IFN-α-iPSC-pMCs in combination with immune checkpoint blockade overcomes resistance to single-treatment modalities and generates long-lasting antitumor immunity. These preclinical data suggest that IFN-α-iPSC-pMCs might constitute effective immune-stimulating agents for cancer that are refractory to checkpoint blockade.

Expression analysis of cellulose synthases that comprise the Type II complex in hybrid aspen

Gene duplication in plants occurs via several different mechanisms, including whole genome duplication, and the copied genes acquire various forms and types. The cellulose synthase (CesA) family functions in cellulose synthesis complex (CSC) formation, which is involved in the synthesis of primary and secondary cell walls in plants. In the genome of Populus, 17 CesA have been annotated, and some of them appeared through whole genome duplication. The nucleotide sequence of the duplicated genes changed during subsequent evolution, and functional differentiation of genes might have occurred. To gain insight into the evolutionary fate of the duplicated CesA, expression analysis with quantitative reverse transcription polymerase chain reactions and promoter-reporter assays was performed on three duplicated gene pairs whose products have been reported to form a single CSC. Changes in expression of each gene at different developmental stages were detected and divergent expression patterns in different organs and tissues observed between the gene pairs. Among the tested genes, expression of PttCesA3-C was apparently lower than that of its counterpart, PttCesA3-D. The results suggest that the six CesA are approaching sub-functionalisation or non-functionalisation. Furthermore, the level of functionalisation may vary among the three pairs of genes, and functional specialisation of each CesA should have been achieved, at least partially, through differences in expression of genes.

Development of heat hyperalgesia and changes of TRPV1 and NGF expression in rat dorsal root ganglion following joint immobilization

The aim of this study was to examine whether threshold to heat stimuli, and expression of transient receptor potential vanilloid1 (TRPV1) and nerve growth factor (NGF) in dorsal root ganglion (DRG) altered under conditions of long-term limb immobilization. A plastic cast was wrapped around the right limb from the forearm to the forepaw to keep wrist joint at 90° of flexion for 5 weeks. Heat hyperalgesia was tested using the plantar test at 6 h after removing cast. The rats were perfused transcardially with 4 % paraformaldehyde and DRGs were excised at 24 h after removing cast. For size distributions of the TRPV1-IR and NGF-IR neuronal profile, the DRG area measurements over 1000 DRG neurons per animal were measured in each side, on both the immobilized (ipsilateral) and contralateral sides. Ipsilateral withdrawal latency was significantly shorter than contralateral sides. Ipsilateral percentage of immunoreactive neurons in the total DRG neurons was significantly higher than contralateral sides in TRPV1-IR and NGF-IR. Long-term casting induced heat hyperalgesia, and up-regulation and phenotypic change of TRPV1-IR and NGF-IR in DRGs on the immobilized side. These DRG alterations may involve heat hyperalgesia after long-term limb immobilization.

Juvenile social experience regulates central neuropeptides relevant to emotional and social behaviors

Stressful social experiences during early-life can increase the risk of developing neuropsychiatric disorders associated with anxiety, mood, and personality. Early neglect also alters peripheral arginine vasopression (AVP) and oxytocin (OXT). We hypothesized that a lack of social stimuli should adversely affect developmental AVP and OXT systems. To test this idea, we examined changes of central AVP- and OXT-immunoreactive (ir) cell number as well as its related behaviors in socially isolated rats. Animals were weaned at 23 days of age, divided into group- or isolation-reared conditions, and maintained for at least 2 weeks. At 38-48 days of age, animals were sacrificed for immunohistochemistry, or used for two behavioral tests: elevated plus-maze test and social recognition test. The results from immunohistochemistry showed that isolation-reared males have decreased AVP-ir cells in the paraventricular nucleus hypothalamus (PVH), medial parvicellular part, ventral zone, and that isolation-reared females have decreased OXT-ir cells in the PVH, medial parvicellular part, dorsal zone, when compared with group-reared counterparts. The results from behavioral assessment showed that isolation-reared animals have difficulty with social recognition, and that isolation-reared males, but not females, have anxiogenic profile. The present study demonstrates that post-weaning social isolation results in decrease of male AVP-ir cells and female OXT-ir cells in the PVH parvocellular divisions, and supports the idea that juvenile social environment may play a critical role in neuronal and behavioral development.

Framework for optimal design of porous scaffold microstructure by computational simulation of bone regeneration

In bone tissue engineering using a biodegradable scaffold, geometry of the porous scaffold microstructure is a key factor for controlling mechanical function of the bone-scaffold system in the regeneration process as well as after the regeneration. In this study, we propose a framework for the optimal design of the porous scaffold microstructure by three-dimensional computational simulation of bone tissue regeneration that consists of scaffold degradation and new bone formation. The rate of scaffold degradation due to hydrolysis, that leads to decrease in mechanical properties, was simply assumed to relate to the water content diffused from the surface to the bulk material. For the new bone formation on both bone and scaffold surfaces, the rate equation of trabecular surface remodeling driven by mechanical stimulation was applied. Solving these two phenomena in the same time frame, the bone regeneration process in the bone-scaffold system was predicted by computational simulation using a voxel finite element method. The change in the mechanical function of the bone-scaffold system during the regeneration process was quantitatively evaluated by measuring the change in total strain energy, and this was used for the evaluation function to optimize the scaffold microstructure that provides the desired mechanical function during and after the bone regeneration process. A case study conducted for the scaffold with a simple microstructure demonstrated that the proposed simulation method could be applied to the design of a porous scaffold microstructure. In addition, the regeneration process was found to be very complex even though the simple rate equations for scaffold regeneration and new bone formation were used because of the coupling effects of these phenomena.

Feedback control in high shear granulation of pharmaceutical powders

A novel system has been developed to control granule growth in high shear granulation. The system basically consisted of an image-processing device and a fuzzy control system. A computer-controlled image processor, an air purge unit, a high-energy xenon lighting system and an image probe with a CCD camera comprised the image processing device. A fuzzy control system using a linguistic algorithm employing if-then rules with a process lag element taken into consideration has been developed to accurately control granule growth without any excessive growth. This newly developed system was applied to actual high shear granulation of pharmaceutical powders and validity of the system was investigated. It was found that the system could control granule growth with high accuracy, regardless of changes in physical properties of starting materials and the operating conditions.

Modulation of dendrodendritic interactions and mitral cell excitability in the mouse accessory olfactory bulb by vaginocervical stimulation

When female mice are mated, they form a memory to the pheromonal signal of their male partner. The neural changes underlying this memory occur in the accessory olfactory bulb, depend upon vaginocervical stimulation at mating and involve changes at the reciprocal synapses between mitral and granule cells. However, the action of vaginocervical stimulation on the reciprocal interactions between mitral and granule cells remains to be elucidated. We have examined the effects of vaginocervical stimulation on paired-pulse depression of amygdala-evoked field potentials recorded in the external plexiform layer of the accessory olfactory bulb (AOB) and the single-unit activity of mitral cells antidromically stimulated from the amygdala in urethane-anaesthetized female mice. Artificial vaginocervical stimulation reduced paired-pulse depression (considered to be due to feedback inhibition of the mitral cell dendrites from the granule cells via reciprocal dendrodendritic synapses) recorded in the AOB external plexiform layer. As would be expected from this result, vaginocervical stimulation also enhanced the spontaneous activity of a proportion of the mitral cells tested. These results suggest that vaginocervical stimulation reduces dendrodendritic feedback inhibition to mitral cells and enhances their activity.

Oxytocin enhances presynaptic and postsynaptic glutamatergic transmission between rat olfactory bulb neurones in culture

Although oxytocin (OT) within the olfactory bulb has been implicated in maternal behaviour and olfactory recognition, the cellular mechanisms of action remain to be clarified. We examined the effects of OT on glutamatergic spontaneous excitatory postsynaptic currents (sEPSCs) in cultured granule cells with the use of whole-cell patch-clamp recordings. OT reversibly increased both the frequency and amplitude of sEPSCs. The effects of OT on sEPSCs were blocked by the selective OT receptor antagonist desGly-NH(2)(9),d (CH(2))(5)-[Thy(Me)(2),Thr(4)]-ornithine vasotocin. OT had no detectable effect, however, on high voltage-activated Ca2+ currents in mitral/tufted cells, suggesting that OT acts presynaptically on step(s) in the release process downstream from calcium influx. OT augmented the membrane current in granule cells evoked by exogenous application of glutamate, indicating a postsynaptic site of action. These results indicate that OT facilitates sEPSCs in granule cells by both pre- and postsynaptic mechanisms.

Quantitative analysis of water dispersion conditions and pressure transmission characteristics of a wet kneaded mass

In our previous paper [Watano S. et al., J. Powder Technology Japan, 37, 362-370 (2000)], a novel compaction tester was developed to quantitatively evaluate the water dispersion condition of a wet kneaded mass prepared by a paddle type kneader. It has been demonstrated that the physical properties of pellets prepared by extrusion granulation after the kneading can be well predicted by the pressure transmission obtained through the compaction tester. This paper describes a more detailed investigation of the water dispersion, its mechanism and pressure transmission characteristics of wet kneaded masses prepared under various operating conditions. First, kneading by a paddle type kneader was conducted to prepare wet masses under various binder contents using different additional methods and different starting materials. Secondly, water dispersion and pressure transmission characteristics of wet masses were investigated. After the wet kneading, the wet kneaded masses were extruded through a dome type extruder and were dried by a fluidized bed to prepare dry pellets. The relationship between water dispersion and pressure transmission can be expressed by a single line, regardless of binder content or methods of addition. This implies that these parameters have no effect on the water dispersion condition of the wet kneaded mass prepared by a high shear paddle type kneader. Different water dispersion characteristics and the mechanism obtained by different starting materials can also be evaluated by the pressure transmission data. Properties of dry pellets can also be predicted by the pressure transmission. It can be concluded that the developed compaction tester can quantitatively evaluate the water dispersion condition of a wet kneaded mass and also predict properties of the final extruded products.

On-line monitoring of granule growth in high shear granulation by an image processing system

A novel system has been developed to continuously monitor granule growth in a high shear granulation. The system consists of an image processing system and a particle image probe comprising a CCD camera, lighting unit and air purge system. Segregation during powder mixing was investigated experimentally and the optimal positioning of the probe was determined. High shear granulation was conducted using pharmaceutical powders, and granule size and product's yield of various size ranges were continuously measured by the developed system. Sieve analysis of the granulated products sampled out during the granulation was simultaneously conducted, and the obtained data was compared with that by the on-line image processing system. An extremely close relationship could be found between both data, proving that the developed system could monitor the granule growth accurately and continuously throughout the granulation. An on-off control system was developed to control the granulation process, and the performance of the system was confirmed.

Oxytocin depresses spontaneous gamma-aminobutyric acid-ergic inhibitory postsynaptic currents in cultured mitral cells of the rat olfactory bulb by a presynaptic mechanism

Oxytocin (OT) modulation of synaptic transmission between olfactory bulb neurones has been implicated in the induction of maternal behaviour, but the mechanism of action is unknown. We examined the action of OT on gamma-aminobutyric acid(A) (GABA(A)) receptor-mediated spontaneous inhibitory postsynaptic currents (sIPSCs) in cultured mitral/tufted (M/T) cells with the use of whole-cell patch-clamp recordings. OT reversibly reduced the frequency of sIPSCs without affecting the amplitudes. The effect of OT on sIPSCs was mimicked by the OT receptor agonist [Thr(4), Gly(7)]-OT in a reversible manner and blocked by the OT receptor antagonist desGly-NH(2)(9), d(CH(2))(5)-[Tyr(Me)(2), Thr(4)]-ornithine-vasotocin. OT has no effect, however, on the membrane currents evoked by exogenous application of GABA. These results demonstrate that OT depresses GABA(A) receptor-mediated sIPSCs in M/T cells by a presynaptic mechanism.

Insulin-induced hypoglycemia activates a chemokinergic neuronal pathway in the hypothalamo-pituitary system

Recently, we found the presence of cytokine-induced neutrophil chemoattractant (CINC) neuronal pathway in the hypothalamo-pituitary system. This observation prompted us to investigate the effect of insulin-induced hypoglycemia on CINC neuronal pathway in the hypothalamo-pituitary system. An insulin injection decreased the plasma glucose level, which followed a prompt rise in plasma ACTH level and an increase in serum CINC level. Before the insulin injection, the signal for CINCmRNA was undetectable in the paraventricular hypothalamic nucleus (PVN). The hypoglycemic challenge induced strong hybridization signals of CINC mRNA in the parvocellular and magnocellular subdivision of the PVN within 30 min, and reached the peak within 3 h. No change was observed in the supraoptic nucleus after the hypoglycemic challenge. These studies demonstrate the presence of a hypoglycemia-sensitive chemokinergic neuronal pathway in the hypothalamo-neurohypophysial system and this newly described pathway will provide novel information for understanding pathophysiology of hypoglycemia.

[Ventricular outflow tract obstruction by cardiac tumors during ACTH therapy of an infant with tuberous sclerosis]

In an infant with tuberous sclerosis and West syndrome, ACTH treatment was interrupted because of augmentation of the biventricular outflow tract obstruction. A 5-month-old boy, who had been diagnosed to have multiple cardiac tumors since in utero, manifested West syndrome with typical hypsarhythmia in EEG. Several days after starting low dose ACTH treatment, a systolic murmur due to biventricular outflow tract obstruction intensified with ventricular arrhythmia. A tumor in the left ventricular outflow tract was enlarged. Discontinuation of daily administration of ACTH and administration of a beta-blocking agent improved the cardiac problems. Acceleration of blood velocity in the outflow tracts disappeared two months later. Intracardiac morphology and hemodynamic performance should be monitored to avoid critical complications during ACTH treatment in patients with tuberous sclerosis.

GRO-alpha in human serum: differences related to age and sex

PROBLEM

Human GRO-alpha (GRO-alpha) is a new member of the chemokine family that is supposed to play an important role in inflammatory and immune reactions. We established a sandwich enzyme-linked immunoassay (ELISA) system with polyclonal antibodies against human GRO-alpha and investigated the serum level of healthy donors to establish normal ranges for this chemokine in adults.

METHODS

GRO-alpha concentrations were measured cross-sectionally in the sera of 240 healthy adults. The variability of serum GRO-alpha levels was also measured in normal volunteers, samples from whom were obtained by sequential venipunctures or by a small plastic cannula with a heparin-saline lock, to determine short-term variability.

RESULTS

Whereas there was no difference between the concentration of human GRO-alpha from men (logarithmic mean, 77.6 pg/ml, n = 120) and that from women with normal menstrual cycles (log mean, 71.6 pg/ml, n = 73), the concentration from postmenopausal women (log mean 45.0 pg/ml, n = 31) was lower than that from women with normal menstrual cycles (log mean 71.6 pg/ml, n = 73). However, we could not detect any significant difference between healthy donors' serum levels and those of donors with acute inflammation. Fewer variations were recognized in the case of the sequential venipunctures method than in that of the heparin-saline lock method.

CONCLUSION

We found that the GRO-alpha concentration of postmenopausal women was significantly lower than that of women with normal menstrual cycles. These results suggest the GRO-alpha serum levels of normal healthy women may have some correlation with sex hormones.

Endotoxin activates a chemokinergic neuronal pathway in the hypothalamo-pituitary system

Cytokines play a critical role in the cascade of events that cause septic shok. One regulatory system suggested to be important in controlling inflammatory response is the neuroendocrine axis. One of the chemokines is cytokine induced neutrophil chemoattractant (CINC), which was first described as an immuno-modulator of peripheral tissue in inflammatory responses. To assess further the contribution of the chemokine to the central nervous system, we performed immunohistochemistry on rat brains and found strong CINC-like immunoreactivity in the posterior pituitary gland. Treatment with bacterial endotoxin (lipopolysaccharide; LPS) markedly enhanced CINC-like immunoreactivity in the posterior pituitary. Before the LPS challenge, signal for CINC mRNA was undetectable in the paraventricular hypothalamic nucleus (PVN). The LPS challenge induced strong hybridization signals of CINC mRNA in the parvocellular and magnocellular subdivision of the PVN within 15 minutes (min) and peaked at 30 min. The LPS challenge provoked no observable change in the supraoptic nucleus. These studies demonstrate the presence of an endotoxin-sensitive chemokinergic neuronal pathway in the hypothalamo-neurohypophysial system and this newly-described pathway will provide a novel information to understand another possible neuralimmune mechanism.

Interleukin-6 stimulates cell proliferation of rat pituitary clonal cell lines in vitro

We investigated the effect of recombinant human IL-6 (rhIL-6) on cell proliferation using the MtT/E rat pituitary tumor cell line, which was recently established by Inoue et al. This cell line expresses the homeodomain protein Pit-1/GHF 1 and does not produce any significant amount of pituitary hormones, but retains its tumorigenicity by back-transplantation into rats, resulting in production of prolactin. MtT/E cells were seeded into Falcon 24-well plates at a density of 2 x 10(4) cells/well in a cultured medium, containing 10% horse serum and 2.5% fetal bovine, with test drug. After four-days (12 days for the time-course study) incubations, the cells were counted using a hemocytometer. Incubation for 4 days with rhIL-6 caused concentration-dependent stimulation of MtT/E cell growth and [3H]-thymidine incorporation into MtT/E cells. Addition of 20 ng/ml rhIL-6 to the culture medium stimulated MtT/E cell growth in a time-dependent manner, withdrawal of rhIL-6 from the culture medium reduced MtT/E cell growth, and re-addition of rhIL-6 to the culture medium again stimulated MtT/E cell growth. Among the cytokines tested, granulocyte colony-stimulating factor (rh G-CSF) also showed a slight but significant mitogenic activity on the MtT/E cells. Analysis of 125I-rhIL-6 binding to the MtT/E cells indicated a dissociation constant of 0.953 x 10(-9) mmol/l and the presence of 968 binding sites per cell.(ABSTRACT TRUNCATED AT 250 WORDS)