Limonoids and unsaturated fatty acids present in Melia toosendan increase ceramide production in keratinocytes.

The skin barrier prevents moisture evaporation and the entry of foreign substances such as allergens. Ceramides are one of the most important factors for maintaining skin barrier function. Melia toosendan is a plant of the Meliaceae family, and its fruit extracts have been used in Traditional Chinese Medicine as analgesics and anthelmintics; however, its ability to increase ceramide levels has not been reported. In this study, we screened for compounds present in M. toosendan fruit extracts that increase ceramide levels in the skin. We fractionated the extracts based on their activity to identify the active components. Nimbolinins, limonoids such as toosendanin, and hydroxylated unsaturated fatty acids were found to be the major active components. The structure-activity relationship of toosendanin derivatives indicated that the sites around R4 and R5 contributed to the activity. To the best of our knowledge, this is the first report showing that limonoids promote ceramide production in skin cells. Therefore, M. toosendan fruit extracts may be used to develop products for improving the skin barrier function.

Sudden onset of sleep caused by hypothalamic infarction: a case report.

BACKGROUND: Hypothalamic lesions, such as tumors and demyelinating diseases, reportedly cause abnormal sleepiness. However, stroke involving the hypothalamus has rarely been described. Here, we report a patient with infarction restricted to the hypothalamus who presented with sudden onset of sleep. CASE PRESENTATION: A 42-year-old woman with a history of migraine without aura presented with irresistible sleepiness and developed several episodes of sudden onset of sleep. Neurological examinations were unremarkable except for partial left Horner syndrome. Brain magnetic resonance imaging (MRI) revealed a high-intensity lesion restricted to the left hypothalamus on diffusion-weighted and fluid-attenuated inversion recovery MRI images. Cerebrospinal fluid (CSF) orexin-A levels obtained on hospital day 3 after her sleepiness had resolved were normal (337 pg/mL; normal > 200 pg/mL). Serum anti-nuclear and anti-aquaporin 4 (AQP4) antibodies and CSF myelin basic protein and oligoclonal band were negative. A small hypothalamic infarction was suspected, and the patient was treated with intravenous edaravone and argatroban, as well as oral clopidogrel. Three months later, there had been no clinical relapse, and the hypothalamic lesion had almost disappeared on follow-up MRI. No new lesion suggestive of demyelinating disease or tumor was observed. CONCLUSION: Hypothalamic stroke should be considered a cause of sudden onset of sleep.

Effects of ammonium hexafluorosilicate concentration on dentin tubule occlusion and composition of the precipitate.

UNLABELLED: Ammonium hexafluorosilicate [SiF: (NH(4))(2)SiF(6)] was prepared in order to overcome the tooth discoloration caused by diamine silver fluoride [AgF: (NH(3))(2)AgF] application. We employed a single concentration of SiF solution in our previous study; therefore, it is still unclear how the concentration of SiF solution affects the occlusion of dentin tubules and composition of the precipitate. OBJECTIVE: The aim of this study was to evaluate the effects of changing the concentration of SiF on its clinical use as a dentin hypersensitivity treatment. METHODS: To simulate dentin tubules subject to dentin hypersensitivity, dentin disks were treated with EDTA for 2 min. Then, the disks were treated with several concentrations of SiF solution (from 100 to 19,400 ppm) for 3 min. The occlusion of dentin tubules was evaluated using scanning electron microscopy (SEM), and the composition of the precipitate formed in the tubules after SiF treatment was assessed using energy dispersive X-ray analysis (EDXA). RESULTS: SEM photographs demonstrated that dentin tubules after treatment with SiF were occluded homogeneously and fully regardless of the concentration of SiF solution. The Ca/P molar ratio of the precipitate formed in dentin tubules after SiF treatment was increased with the concentration of SiF solution. SIGNIFICANCE: It was concluded that the capacity to occlude dentin tubules was the same regardless of the concentration of SiF solution. However, the composition of the precipitate formed in the tubules was dependent on the concentration of SiF solution.

Particular subpopulations of midbrain and hypothalamic dopamine neurons express vesicular glutamate transporter 2 in the rat brain.

Vesicular glutamate transporters (VGLUT1, -2, and -3) mediate the accumulation of transmitter glutamate into synaptic vesicles in glutamatergic neurons. VGLUT1 and VGLUT2 are more reliable glutamatergic neuron markers, since VGLUT3 also exists in other neuron types. To study whether the dopaminergic neuron uses glutamate as a cotransmitter, we analyzed VGLUTs expression in dopamine neurons of adult male rats by in situ hybridization and immunohistochemistry. In the ventral midbrain, in situ hybridization analysis revealed no VGLUT1 mRNA expression, a widespread but discrete pattern of VGLUT2 mRNA expression, and a highly limited expression of VGLUT3 mRNA. Reverse-transcriptase polymerase chain reaction analysis detected full-length VGLUT2 gene transcripts in the ventral midbrain. Using in situ hybridization combined with tyrosine hydroxylase (TH) immunostaining, only VGLUT2 signals were detectable in some TH-labeled neurons of A10 dopamine neuron groups, with the highest incidence (20%) in the rostral linear nucleus of the ventral tegmental area. In the forebrain, VGLUT2 signals were demonstrated in half of the A11 TH-labeled neurons in the hypothalamus. Double-label immunostaining for VGLUT2 and vesicular monoamine transporter 2 or TH showed that double-labeled varicosities are rarely observed in any target regions examined of A10 and A11 dopamine neuron groups. These results indicate that VGLUT2 is expressed in subsets of A10 and A11 dopamine neurons, which might release dopamine and glutamate separately from different varicosities in the majority of their single axons.

Effect of ammonium hexafluorosilicate on dentin tubule occlusion for the treatment of dentin hypersensitivity.

PURPOSE: To evaluate the occluding ability of ammonium hexafluorosilicate (SiF). METHODS: Dentin disks prepared from human extracted teeth were grouped as follows to prepare different situations of dentin hypersensitivity: (1) those sonicated for 20 minutes; (2) those treated with 0.5 mol/L EDTA for 2 minutes; (3) those treated with 6% citric acid for 2 minutes; (4) those treated with 50% citric acid for 2 minutes. Then, SiF or diamine silver fluoride (AgF) was applied to the dentin disks and the dentin tubule occlusion was observed with scanning electron microscopy (SEM). The percent of open tubules before and after SiF or AgF treatment were measured by NIH image using SEM photographs. Also, the dentin permeability was measured. RESULTS: SEM micrographs demonstrated that the dentin tubules were completely occluded by the precipitate after SiF treatment. Also, the dentin permeability was reduced to 10.3%. In contrast, most of the dentin tubules remained open after AgF treatment. EDXA analysis showed that the precipitate in the dentin tubules that forms after SiF treatment contains Si, Ca and P, indicating a silica-calcium phosphate complex.

Up-regulation of VGLUT2 expression in hypothalamic-neurohypophysial neurons of the rat following osmotic challenge.

A second vesicular glutamate transporter (VGLUT2) has been reported to be expressed in neurosecretory neurons of the hypothalamic-neurohypophysial system. To study its role in the neurosecretory neurons, we evaluated the expression of the VGLUT2 gene in the paraventricular (PVN) and supraoptic (SON) nuclei as well as the immunoreactivity in the neurohypophysis under euhydrated and chronic hyperosmotic conditions with in situ hybridization and immunohistochemistry. The intensity of hybridization signals in the PVN, SON and thalamus of rats subjected to water deprivation for 7 days, or drinking 2% NaCl for 4 or 7 days, was compared with that of euhydrated rats (control). The overall intensity in the entire PVN or SON, but not the thalamus, was higher in osmotically stimulated rats than in controls. Within the PVN, a significantly higher intensity of signals than that of controls was found only in the dorsolateral posterior magnocellular region in 4-day salt-loaded rats and in all subregions in water-deprived or 7-day salt-loaded rats. The intensity in the SON was higher in the stimulated rats than in controls, regardless of subregions. In the neurohypophysis, VGLUT2 staining was frequently localized in vasopressin terminals of control rats and was apparently reduced in stimulated rats. These results indicate that VGLUT2 is principally expressed in magnocellular vasopressin neurons, suggesting some local effect of intrinsic glutamate on neurohypophysial hormone secretion.