Dedifferentiated Fat (DFAT) cells: A cell source for oral and maxillofacial tissue engineering.

Tissue engineering is a promising method for the regeneration of oral and maxillofacial tissues. Proper selection of a cell source is important for the desired application. This review describes the discovery and usefulness of dedifferentiated fat (DFAT) cells as a cell source for tissue engineering. Dedifferentiated Fat cells are a highly homogeneous cell population (high purity), highly proliferative, and possess a multilineage potential for differentiation into various cell types under proper in vitro inducing conditions and in vivo. Moreover, DFAT cells have a higher differentiation capability of becoming osteoblasts, chondrocytes, and adipocytes than do bone marrow-derived mesenchymal stem cells and/or adipose tissue-derived stem cells. The usefulness of DFAT cells in vivo for periodontal tissue, bone, peripheral nerve, muscle, cartilage, and fat tissue regeneration was reported. Dedifferentiated Fat cells obtained from the human buccal fat pad (BFP) are a minimally invasive procedure with limited esthetic complications for patients. The BFP is a convenient and accessible anatomical site to harvest DFAT cells for dentists and oral surgeons, and thus is a promising cell source for oral and maxillofacial tissue engineering.

Simulation training for medical emergencies in the dental setting using an inexpensive software application.

INTRODUCTION: Every dental provider needs to be educated about medical emergencies to provide safe dental care. Simulation training is available with simulators such as advanced life support manikins and robot patients. However, the purchase and development costs of these simulators are high. We have developed a simulation training course on medical emergencies using an inexpensive software application. The purpose of this study was to evaluate the educational effectiveness of this course. MATERIALS AND METHODS: Fifty-one dental providers participated in this study from December 2014 to March 2015. Medical simulation software was used to simulate a patient's vital signs. We evaluated participants' ability to diagnose and treat vasovagal syncope or anaphylaxis with an evaluation sheet and conducted a questionnaire before and after the scenario-based simulation training. RESULTS: The median evaluation sheet score for vasovagal syncope increased significantly from 7/9 before to 9/9 after simulation training. The median score for anaphylaxis also increased significantly from 8/12 to 12/12 (P < .01). For the item "I can treat vasovagal syncope/anaphylaxis adequately," the percentage responding "Strongly agree" or "Agree" increased from 14% to 56% for vasovagal syncope and from 6% to 42% for anaphylaxis with simulation training. CONCLUSIONS: This simulation course improved participants' ability to diagnose and treat medical emergencies and improved their confidence. This course can be offered inexpensively using a software application.

Cerebellopontine angle mass mimicking lingual nerve injury after dental implant placement: a case report.

This is a rare case report of a cerebellopontine angle (CPA) mass mimicking lingual nerve injury after a dental implant placement. Lingual nerve injury is a common complication following dental implant placement. CPA masses are likely to cause symptomatic trigeminal neuralgia, and thus can mimic and be easily confused with oral diseases. We experienced a case of CPA mass mimicking lingual nerve injury after dental implant placement. The patient was a 57-year-old Japanese female who complained of glossalgia. She underwent dental implant placement in the mandible before visiting our clinic. Panoramic x-ray radiography revealed no abnormalities; the salivary flow rate by gum test was 7.0 ml/10 min. She was diagnosed with lingual nerve injury and secondary burning mouth syndrome. Vitamin B12 and oral moisturizer did not provide relief; furthermore, numbness in the lower lip emerged. A Semmes Weinstein test demonstrated elevation of her sensitivity threshold. Finally, magnetic resonance imaging revealed a 20-mm diameter mass in the CPA. The patient is now being followed under conservative management. Our experience underscores the importance of including CPA mass in the differential diagnosis of dental diseases.

DNA demethylating agent decitabine increases AQP5 expression and restores salivary function.

Xerostomia is the symptom of oral dryness resulting most frequently, but not exclusively, from salivary gland hypofunction. Because the prevalence of xerostomia may increase with age, it has multiple oral health consequences in aging populations. In the present study, we demonstrate that the in vivo administration of 5-aza-2'-deoxycytidine (5-Aza-CdR; decitabine), a DNA demethylating agent, to the murine aging model C57BL/6CrSlc mice (24 wks old) increased the volumes of salivary flow compared with those of control mice. Western blot analysis and immunohistochemical staining demonstrated the augmented expression of AQP5 protein in the salivary glands of 5-Aza-CdR-treated mice compared with those of control mice. In addition, AQP5 protein expression levels in 5-Aza-CdR-treated old mice (27 wks old) were much higher than those in untreated and young mice (6 wks old). Global methylation levels in the salivary glands were significantly lower in the 5-Aza-CdR-treated mice than in the untreated mice. Moreover, the induction of demethylation in the AQP5 promoter of 5-Aza-CdR-treated mice was stronger than in the control mice. Analysis of our data therefore suggests that a DNA demethylating agent may be a useful drug for restoring hyposalivation in elderly individuals, thereby leading to the resolution of xerostomia.

Psoriatic skin expresses the transcription factor Gli1: possible contribution of decreased neurofibromin expression.

BACKGROUND: Psoriasis is a chronic inflammatory disorder of skin characterized by hyperproliferation of keratinocytes. Intracellular signalling pathways inducing the hyperproliferation of keratinocytes remain to be elucidated. An inhibitor of Hedgehog (Hh) signalling, cyclopamine, was recently reported to clear psoriatic skin lesions, suggesting involvement of the Hh signalling pathway in the hyperproliferation of lesional keratinocytes. We have previously observed activation of the Hh signalling pathway in Schwann cells of plexiform neurofibroma in neurofibromatosis type 1 (NF1), which results from functional loss of the NF1 encoding protein, neurofibromin. In psoriasis, deficiency of neurofibromin expression has been observed in lesional keratinocytes. OBJECTIVES: To investigate whether the Hh signalling pathway would be activated in psoriasis and whether inhibition of neurofibromin expression would enhance the activation of the Hh signalling pathway. METHODS: Activation of the Hh signalling pathway was examined by protein expression of one of the target genes, GLI1, coding for the transcription factor Gli1. Immunohistochemical studies were performed on seven psoriatic skin samples and seven control normal skin samples with a standard immunoperoxidase technique. mRNA expression of GLI1 was analysed by reverse transcriptase-polymerase chain reaction in HaCaT cells transfected with double-strand small interfering RNA for NF1. RESULTS: Our results showed Gli1 expression in psoriatic skin but not in control normal skin. Inhibition of neurofibromin expression in HaCaT cells upregulated mRNA expression of GLI1. CONCLUSIONS: Our findings indicate that the Hh signalling pathway is activated in psoriasis and that neurofibromin deficiency may upregulate the pathway.

Squamous metaplasia of Paget's disease.

A patient had triple extramammary Paget's disease of both axillary and genital regions. Right inguinal lymphadenopathy was found 1 year after excision of all the skin lesions. Excisional biopsy of the lymph node demonstrated a mixture of Paget cells and atypical squamoid cells with horn pearls suggestive of keratinization. The squamoid cells were positive for cytokeratin 10, a marker of suprabasal epidermis, and also positive for laminin gamma2 which is often expressed in invasive squamous cell carcinoma. The coexistence of these different cells within the same tumour island suggested that the squamoid cells derived from metaplasia of Paget cells.

Concentrations of lidocaine and monoethylglycine xylidide in brain, cerebrospinal fluid, and plasma during lidocaine-induced epileptiform electroencephalogram activity in rabbits: the effects of epinephrine and hypocapnia.

UNLABELLED: When injecting lidocaine into tissues, the mean toxic dose of lidocaine may be increased by adding epinephrine to lidocaine and by decreasing the PaCO(2). In contrast, when lidocaine is introduced directly into an artery or vein, adding epinephrine to lidocaine may decrease the mean toxic dose of lidocaine. Less is known about the effects of decreased PaCO(2) on intravascular lidocaine toxicity. We infused lidocaine in 24 rabbits at 4 mg. kg(-1). min(-1) with/without epinephrine and with/without hypocapnia. We measured the time to onset of lidocaine-induced seizures, total dose of lidocaine at the time of seizures, and concentrations of lidocaine and monoethylglycine xylidide (MEGX), a metabolite of lidocaine, in plasma, brain, and cerebrospinal fluid. Epinephrine decreased onset time by 11% with hypocapnia and by 21% with normocapnia, and it increased plasma MEGX by 1 microg/mL with hypocapnia and 2 microg/mL with normocapnia. Hypocapnia increased onset time by 18% without epinephrine and by 33% with epinephrine, and it increased whole-brain MEGX by 10 microg/mL without epinephrine and by 14 microg/mL with epinephrine. We conclude that, when lidocaine is given intravascularly, hypocapnia increases onset time and lidocaine dose required for seizures. These effects occur with no change in the concentration of lidocaine in plasma or the brain. IMPLICATIONS: Hypocapnia increases the toxic dose of lidocaine given IV without altering lidocaine concentrations in blood, brain, or cerebrospinal fluid. Whole-brain monoethylglycine xylidide concentration is greater during hypocapnia than during normocapnia, and the addition of epinephrine to lidocaine increases the concentration of monoethylglycine xylidide in plasma.

Trabecular outflow facility and formation rate of aqueous humor during anesthesia with sevoflurane-nitrous oxide or sevoflurane-remifentanil in rabbits.

UNLABELLED: In the present study, we examined the effect of sevoflurane and remifentanil on intraocular pressure (IOP) and fluid dynamics. Twenty-eight rabbits were anesthetized with halothane, and IOP was measured via a 25-gauge needle in the anterior chamber. Rabbits were then assigned to one of four groups, and halothane was replaced with sevoflurane 1% (n = 7), 2% (n = 7), 3% (n = 7), or 1% + remifentanil 0.65 microg kg(-1) x min(-1) i.v. (n = 7). In all groups, a series of intraocular infusions was made into the anterior chamber, and IOP, trabecular outflow facility, the rate of aqueous humor formation, and intraocular compliance were determined. With sevoflurane only, intraocular compliance decreased (55 +/- 14, 39 +/- 22, 31 +/- 17 nL/mm Hg; P < 0.05) as the concentration of sevoflurane increased. With sevoflurane 1% + remifentanil, intraocular compliance was significantly increased (100.1 +/- 30.5 nL/mm Hg; P < 0.05) compared with sevoflurane 1%, 2%, or 3%. Trabecular outflow facility, rate of aqueous humor formation, and IOP did not differ among groups, and IOP was similar to values obtained during halothane anesthesia. IMPLICATIONS: The dose-related effects of sevoflurane on intraocular compliance did not produce significant intraocular pressure differences. Adding remifentanil to sevoflurane increased intraocular compliance. Sevoflurane or sevoflurane + remifentanil causes a decrease in intraocular pressure compared with the average of previously reported values in awake rabbits, and the magnitude of the decrease is similar to that previously reported in rabbits anesthetized with ethyl urethane, pentobarbital, or halothane alone or in combination with propofol, cocaine, or lidocaine.

Posttreatment with propofol terminates lidocaine-induced epileptiform electroencephalogram activity in rabbits: effects on cerebrospinal fluid dynamics.

UNLABELLED: There are no controlled studies to determine whether propofol given after the onset of lidocaine-induced seizures (posttreatment) stops lidocaine-induced seizures. In this study, we determined whether posttreatment with propofol abolishes lidocaine-induced epileptiform electroencephalogram (EEG) activity as effectively as does midazolam, and cerebrospinal fluid (CSF) dynamics during lidocaine-induced epileptiform EEG activity and its treatment. EEG activity and CSF dynamics were determined in two groups of anesthetized rabbits at each of four experimental conditions: baseline, lidocaine-induced epileptiform activity, treatment with midazolam (n = 6) or propofol (n = 6), and return to baseline. The analog EEG signal was converted into a set of digital parameters using aperiodic analysis, and CSF dynamics were determined using ventriculocistemal perfusion. Propofol (3.8 +/- 1.3 mg/kg) stopped epileptiform activity, as did midazolam (2.0 +/- 1.7 mg/kg). The rates of CSF formation or reabsorption and resistances to CSF reabsorption or flow at the arachnoid villi did not differ among conditions or between groups. Our results indicate that propofol and midazolam both terminate epileptiform activity without changing CSF dynamics. IMPLICATIONS: Propofol may be an alternative to benzodiazepines for treating lidocaine-induced epileptiform electroencephalogram activity in patients.

Blockade of neuropsin, a serine protease, ameliorates kindling epilepsy.

The behavioural and electrographical abnormalities associated with seizures in epileptic (kindled) mice correspond with those of human epilepsy. In kindled mice, neuropsin was markedly increased in the hippocampus and cerebral cortices. A single intraventricular injection of monoclonal antibodies specific to neuropsin reduced or eliminated the epileptic pattern noted on electroencephalograms and, as a result markedly inhibited the progression of kindling. Therefore, neuropsin appears to be a key protein controlling pathogenic events in the hippocampus, and thus neuropsin inhibitors might be useful for treatment of epilepsy.

Characterization of recombinant and brain neuropsin, a plasticity-related serine protease.

Activity-dependent changes in neuropsin gene expression in the hippocampus implies an involvement of neuropsin in neural plasticity. Since the deduced amino acid sequence of the gene contained the complete triplet (His-Asp-Ser) of the serine protease domain, the protein was postulated to have proteolytic activity. Recombinant full-length neuropsin produced in the baculovirus/insect cell system was enzymatically inactive but was readily converted to active enzyme by endoprotease processing. The activational processing of prototype neuropsin involved the specific cleavage of the Lys32-Ile33 bond near its N terminus. Native neuropsin that was purified with a purity of 1,100-fold from mouse brain had enzymatic characteristics identical to those of active-type recombinant neuropsin. Both brain and recombinant neuropsin had amidolytic activities cleaving Arg-X and Lys-X bonds in the synthetic chromogenic substrates, and the highest specific activity was found against Boc-Val-Pro-Arg-4-methylcoumaryl-7-amide. The active-type recombinant neuropsin effectively cleaved fibronectin, an extracellular matrix protein. Taken together, these results indicate that this protease, which is enzymatically novel, has significant limbic effects by changing the extracellular matrix environment.

Expression of neuropsin mRNA in the mouse embryo and the pregnant uterus.

Neuropsin is a novel serine protease whose mRNA is expressed in the mouse central nervous system. We examined the expression of neuropsin mRNA during embryonic development using Northern and in situ hybridization in non-neural tissues. The pregnant uterus showed strong expression of neuropsin mRNA, whereas the nonpregnant uterus did not express this mRNA. Expression was first detected in the primary decidual zone at 5.5 days post coitum and was maximized at 10 days post coitum, decreasing remarkably thereafter. During mouse organogenesis, neuropsin expression was observed in the developing heart, lung, thymus, pituitary, choroid plexus, and epithelial linings of the skin, oral cavity, tongue, esophagus, and forestomach. In adult mouse organs, neuropsin mRNA was expressed in epithelial tissues covered by keratinocytes with moderate density, whereas low expression was observed in lung, thymus, and spleen. Neuropsin mRNA expression in developing organs and adult keratinocytes suggests that neuropsin is associated with extracellular matrix modifications and cell migrations.

Localization of a G-protein-coupled inwardly rectifying K+ channel, CIR, in the rat brain.

The cellular localization of a G-protein-coupled K+ channel, CIR, in the rat brain has been demonstrated using a CIR-specific antibody, in combination with in situ hybridization. The CIR protein and messenger RNA were found in the cerebellar cortex, hippocampal formation, olfactory system, cerebral cortex, basal ganglia, several nuclei of the lower brain stem and the choroid plexus. In contrast to the messenger RNA, which was concentrated in the cell soma, the CIR protein was found in a subset of nerve fibers and, in other cases, in axon terminals. In the cerebellar cortex and hippocampus, the CIR protein was concentrated in the axon terminals of basket cells which are known to be GABAergic interneurons. This discrepancy between the distribution of protein and messenger RNA was observed in the substantia nigra, the interpeduncular, trigeminal, hypoglossal, oculomotor and red nuclei of the lower brain stem, and the tufted and mitral cells of the olfactory bulb. These observations suggested the translocation of the CIR protein into the nerve fibers following synthesis in the cell soma. Furthermore, its specific neuronal localization, especially in GABAergic interneurons, suggested the importance of CIR in synaptic transmission in neuronal systems.

Kindling induces neuropsin mRNA in the mouse brain.

Neuropsin mRNA expression was analyzed and mapped in the mouse brains after kindling epileptogenesis by using in situ hybridization histochemistry. Dynamic increases of the neuropsin mRNA were observed in the layer II of prelimbic, somatosensory, auditory, perirhinal, entorhinal, and piriform cortices in an activity-dependent manner, though no neuropsin gene was expressed in these areas in control mice. In addition to the confirmation of our previous studies showing increases of mRNA in the hippocampus and amygdaloid complex, there were also remarkable increases of the neuropsin mRNA in the limbic areas, such as the accessory olfactory nucleus, the medial and lateral septal nucleus, the nucleus of diagonal band, the substantia innominata and the zona incerta. The dynamic activity-dependent changes of the gene expression and the site-specificity of neuropsin localization are suggesting that this molecule is implicated in cortical- and limbic-specific neuronal reorganization.

Ontogeny of neuropsin mRNA expression in the mouse brain.

In our previous study, we found a novel gene encoding a serine protease termed neuropsin (NP) which exhibited activity-dependent gene expression or repression in the mouse hippocampus (Chen et al., 1995). In the present study, we examined the ontogeny of NP mRNA expression by in situ hybridization in the brain. Weak hybridization signals were also observed in the choroid plexus at this stage in addition to neuronal labeling. The signals continued to show this localization pattern until postnatal day 12. After embryonic day 18, the number of hybridization signals localized in the neurons of the forebrain limbic area were more predominant than those in the lower brainstem. NP gene expression spread in the anterior olfactory nucleus, hippocampus, septal nuclei, diagonal band of Broca, amygdala and limbic cortex successively from early embryonic to adult stage, though signals in the other brain regions were gradually decreased after birth. Thus, the widespread localization and two types of expression pattern, constitutive or transient, suggest that NP is a multiple functional protein involved in development, neuronal plasticity and cerebrospinal fluid production.

Expression and activity-dependent changes of a novel limbic-serine protease gene in the hippocampus.

A novel murine cDNA which encodes a protein designated neuropsin was cloned. Northern and in situ hybridization analyses demonstrated that neuropsin mRNA is expressed specifically in the limbic system of mouse brain and is localized at highest concentration in pyramidal neurons of the hippocampal CA1-3 subfields. Direct hippocampal stimulation and kindling induced by amygdaloid stimulation caused a significant bilateral change in neuropsin mRNA level in the hippocampal pyramidal neurons. The activity-dependent changes and the specific localization indicate that neuropsin is involved in hippocampal plasticity.

Central nervous system arteriovenous malformations with hereditary hemorrhagic telangiectasia: report of a family with three cases.

A family with central nervous system (CNS) arteriovenous malformations (AVMs) and hereditary hemorrhagic telangiectasia (HHT) is reported. A 46-year-old man had an intracerebral hemorrhage. Cerebral angiography showed one AVM and two angiomas. The HHT was diagnosed because of the concomitant existence of cutaneous telangiectasia. The patient's brother had HHT and paraplegia since the age of 21. Magnetic resonance imaging revealed an old spinal cord hemorrhage. The patient's son with HHT had an intracerebral hemorrhage at age 6. Angiograms showed two AVMs and one angioma. Familial CNS AVMs with HHT are extremely rare. The loci for human leukocyte antigen of the affected cases with HHT were evaluated, and the management of CNS AVMs with HHT is discussed.

Electron microscopic observation of bFGF immunoreactivity in the hippocampus.

Light and electron microscopic observation showed two types of neuronal immunostaining for basic fibroblast growth factor in the hippocampal CA2 subfield, where the densest immunoreactive neurons were localized in the brain. One neuronal type showed intense nuclear (eu- and heterochromatin) immunostaining but weak cytoplasmic immunostaining (N-type), and the other showed intense cytoplasmic but no or only faint nuclear immunoreactivity (C-type). The N-type also showed weak immunoreactivity in the perinuclear rough endoplasmic reticulum and contained bFGF mRNA as observed by in situ hybridization histochemistry, showed that this type can produces the bFGF protein. The N-type localized exclusively in the CA2 subfield. The C-type showed strong immunoreactivity on the rER, free ribosomes, and Golgi apparatus, although no clear evidence for bFGF production was observed. The multivesicular bodies, a pathway of endocytosis in hippocampal neurons showed apparent immunoreactivity under EM observation of both of types neurons (Parton et al. J. Cell Biol. 119: 123-137, 1992) suggesting a receptor-mediated type of incorporation of the bFGF.

Basal magnocellular and pontine cholinergic neurons coexpress FGF receptor mRNA.

By in situ hybridization histochemistry, fibroblast growth factor receptor gene (flg)-expressing neurons were newly identified in the basal magnocellular nuclei (the vertical and horizontal limbs of the diagonal band, and Meynert's nucleus). The present study also confirmed flg localization in the laterodorsal tegmental nucleus and the pedunculopontine tegmental nucleus of the pons. Immuno- and in situ hybridization histochemistry on the same sections demonstrated that choline acetyltransferase and flg were colocalized in single neurons of the diagonal band, Meynert's nucleus and the pontine tegmental areas. The results suggest that a significant number of the basal magnocellular and a majority of the mesopontine cholinergic neurons are directly affected by fibroblast growth factors (FGF) via FGF receptor gene.