LDL uptake-dependent phosphatidylethanolamine translocation to the cell surface promotes fusion of osteoclast-like cells.

Osteoporosis is associated with vessel diseases attributed to hyperlipidemia, and bone resorption by multinucleated osteoclasts is related to lipid metabolism. In this study, we generated low-density lipoprotein receptor (LDLR)/lectin-like oxidized LDL receptor-1 (LOX-1, also known as Olr1) double knockout (dKO) mice. We found that, like LDLR single KO (sKO), LDLR/LOX-1 dKO impaired cell-cell fusion of osteoclast-like cells (OCLs). LDLR/LOX-1 dKO and LDLR sKO preosteoclasts exhibited decreased uptake of LDL. The cell surface cholesterol levels of both LDLR/LOX-1 dKO and LDLR sKO osteoclasts were lower than the levels of wild-type OCLs. Additionally, the amount of phosphatidylethanolamine (PE) on the cell surface was attenuated in LDLR/LOX-1 dKO and LDLR sKO preosteoclasts, whereas the PE distribution in wild-type OCLs was concentrated on the filopodia in contact with neighboring cells. Abrogation of the ATP binding cassette G1 (ABCG1) transporter, which transfers PE to the cell surface, caused decreased PE translocation to the cell surface and subsequent cell-cell fusion. The findings of this study indicate the involvement of a novel cascade (LDLR∼ABCG1∼PE translocation to cell surface∼cell-cell fusion) in multinucleation of OCLs.

Association of Multiple Gene Polymorphisms Including Homozygous NUDT15 R139C With Thiopurine Intolerance During the Treatment of Acute Lymphoblastic Leukemia.

Although thiopurine is a crucial drug for treating acute lymphoblastic leukemia, individual variations in intolerance are observed due to gene polymorphisms. A 3-year-old boy with B-cell precursor acute lymphoblastic leukemia who was administered thiopurine developed mucositis, sepsis, and hemophagocytic lymphohistiocytosis due to prolonged hematologic toxicity, chronic disseminated candidiasis, and infective endocarditis that triggered multiple brain infarctions. The patient was found to harbor 3 gene polymorphisms associated with thiopurine intolerance including homozygous NUDT15 R139C, heterozygous ITPA C94A, and homozygous MTHFR C677T and heterozygous RFC1 G80A. Thus, the combined effect of intolerance via multiple gene polymorphisms should be considered in case of unexpected adverse reactions.

Does TMJ Function and Imaging Tools Help Differentiate Between Condylar Resorption and Mandibular Hypoplasia?

PURPOSE: Differentiating between bilateral condylar resorption (CR) and mandibular hypoplasia (MH) can be challenging owing to the difficulty in chronological observation and establishing standardized measurements. The purpose of the present study was to assess whether temporomandibular joint (TMJ) function can distinguish between CR and MH and clarify the essential diagnostic imaging tools for CR. MATERIALS AND METHODS: We performed a cross-sectional study of patients with mandibular retrognathia. The primary predictor variables were a clinical dysfunction score for the TMJ, mandibular plane angle (MPA), SNA angle, SNB angle, and cortical erosion score in the condylar heads. The demographic variables were age, anterior disc displacement, and previous orthodontic treatment. The anatomic variable was the condylar height (CH). The primary outcome variable was the disease status (CR or MH). The patients were divided into the CR group and MH group. The patients with CR were selected on the basis of a CH value of less than 22 mm. TMJ function was assessed using the Helkimo clinical dysfunction index. The CH on panoramic radiographs was measured using the Kjellberg method. The MPA, SNA angle, and SNB angle were analyzed using cephalometric analysis. Cortical erosion in the condylar head was assessed using computed tomography and magnetic resonance imaging. RESULTS: A total of 23 female participants were enrolled in the present study. The average clinical dysfunction score for the TMJ was 4.4 in the CR group and 0.4 in the MH group (P < .05). The average MPA was 41.2° in the CR group and 35.5° in the MH group (P < .05). CONCLUSIONS: The present investigation has shown that assessing TMJ function and analyzing MPA using a cephalometric radiograph can differentiate CR from MH.

Tumor-associated macrophages in oral premalignant lesions coexpress CD163 and STAT1 in a Th1-dominated microenvironment.

BACKGROUND: Tumor-associated macrophages (TAMs) are implicated in the growth, invasion and metastasis of various solid tumors. However, the phenotype of TAMs in premalignant lesions of solid tumors has not been clarified. In the present study, we identify the phenotype of TAMs in leukoplakia, an oral premalignant lesion, by immunohistochemical analysis and investigate the involvement of infiltrated T cells that participate in the polarization of TAMs. METHODS: The subjects included 30 patients with oral leukoplakia and 10 individuals with normal mucosa. Hematoxylin and eosin slides were examined for the histological grades, and immunohistochemical analysis was carried out using antibodies against CD68 (pan-MΦ), CD80 (M1 MΦ), CD163 (M2 MΦ), CD4 (helper T cells: Th), CD8 (cytotoxic T cells), CXCR3, CCR5 (Th1), CCR4 (Th2), signal transducer and activator of transcription (STAT1), phosphorylated STAT1 (pSTAT1) and chemokine CXCL9. The differences in the numbers of positively stained cells among the different histological grades were tested for statistical significance using the Kruskal-Wallis test. Correlations between different types of immune cells were determined using Spearman's rank analysis. RESULTS: An increase in the rate of CD163(+) TAM infiltration was observed in mild and moderate epithelial dysplasia, which positively correlated with the rate of intraepithelial CD4(+) Th cell infiltration. Although CCR4(+) cells rarely infiltrated, CXCR3(+) and CCR5(+) cells were observed in these lesions. Cells positive for STAT1 and chemokine CXCL9, interferon- (IFN)-induced gene products, and pSTAT1 were also observed in the same lesions. Double immunofluorescence staining demonstrated that the cells that were positive for CD163 were also positive for STAT1. CONCLUSIONS: CD163(+) TAMs in oral premalignant lesions coexpress CD163 and STAT1, suggesting that the TAMs in oral premalignant lesions possess an M1 phenotype in a Th1-dominated micromilieu.

Barometric and tidal-induced aquifer water level fluctuation near the Ariake Sea.

Observations of water levels in coastal aquifers and corresponding tides coupled with meteorological variances near the Ariake Sea show that groundwater in this area mainly fluctuates with atmospheric and tidal variations. Tidal effects occur with semi-monthly, diurnal, or semi-diurnal periodicity, whereas the barometric influences commonly act in the low-frequency domain. Tidal and barometric effects in water levels are separable using wavelet techniques and can be evaluated statistically. Results show the following. (1) The tidal coefficients are 0.002-0.154, attenuating roughly exponentially from the seashore. The time lags in water levels increase linearly approximately with increasing inshore distance. Relations between tidal coefficients and time lags and the inshore distance indicate higher hydraulic diffusivity in the south aquifer, which was confirmed by the hydraulic property calibrations in analytical simulations. (2) Water levels related to meteorological phenomena fluctuate inversely according to barometric loading variation with time lags of 2-3 h. The effective barometric efficiencies are 0.022-0.12. Lower barometric influences were found in the south aquifer.

Brexpiprazole I: in vitro and in vivo characterization of a novel serotonin-dopamine activity modulator.

Brexpiprazole (OPC-34712, 7-{4-[4-(1-benzothiophen-4-yl)piperazin-1-yl]butoxy}quinolin-2(1H)-one) is a novel drug candidate in clinical development for psychiatric disorders with high affinity for serotonin, dopamine, and noradrenaline receptors. In particular, it bound with high affinity (Ki < 1 nM) to human serotonin 1A (h5-HT1A)-, h5-HT2A-, long form of human D2 (hD2L)-, hα1B-, and hα2C-adrenergic receptors. It displayed partial agonism at h5-HT1A and hD2 receptors in cloned receptor systems and potent antagonism of h5-HT2A receptors and hα1B/2C-adrenoceptors. Brexpiprazole also had affinity (Ki < 5 nM) for hD3-, h5-HT2B-, h5-HT7-, hα1A-, and hα1D-adrenergic receptors, moderate affinity for hH1 (Ki = 19 nM), and low affinity for hM1 receptors (Ki > 1000 nM). Brexpiprazole potently bound to rat 5-HT2A and D2 receptors in vivo, and ex vivo binding studies further confirmed high 5-HT1A receptor binding potency. Brexpiprazole inhibited DOI (2,5-dimethoxy-4-iodoamphetamine)-induced head twitches in rats, suggestive of 5-HT2A antagonism. Furthermore, in vivo D2 partial agonist activity of brexpiprazole was confirmed by its inhibitory effect on reserpine-induced DOPA accumulation in rats. In rat microdialysis studies, brexpiprazole slightly reduced extracellular dopamine in nucleus accumbens but not in prefrontal cortex, whereas moderate increases of the dopamine metabolites, homovanillic acid and DOPAC (3,4-dihydroxy-phenyl-acetic acid), in these areas also suggested in vivo D2 partial agonist activity. In particular, based on a lower intrinsic activity at D2 receptors and higher binding affinities for 5-HT1A/2A receptors than aripiprazole, brexpiprazole would have a favorable antipsychotic potential without D2 receptor agonist- and antagonist-related adverse effects. In conclusion, brexpiprazole is a serotonin-dopamine activity modulator with a unique pharmacology, which may offer novel treatment options across a broad spectrum of central nervous system disorders.

Features of brain magnetic resonance imaging diffusion-weighted images of aortogenic embolic stroke.

BACKGROUND: The features of acute aortogenic embolic stroke on magnetic resonance diffusion-weighted imaging (DWI) have not been fully elucidated, so we compared patients with acute aortogenic embolic stroke and those with acute cardioembolic stroke. METHODS AND RESULTS: This study included 40 consecutive patients with acute aortogenic embolic stroke, and 40 age- and sex-matched patients with acute cardioembolic stroke. The diagnosis of aortogenic embolic stroke was made when patients met 5 criteria: (1)acute neurologic event lasting >24h; (2) positive signals on DWI; (3) atherosclerotic lesions ≥3.5-mm thick at the aortic arch on transesophageal echocardiography; (4) neuroradiologic features suggesting embolic stroke, such as lesions involving the brain cortex or the re-opening phenomenon of previously occluded vessels on Magnetic Resonance Angiography (MRA); and (5) absence of other embolic sources, including heart disease and carotid stenosis. The number, site, and maximal diameter of the infarct lesions on DWI were compared between the aortogenic and cardiogenic groups. The aortogenic patients more frequently had ≥3 lesions (25.0% vs. 2.5%, P<0.01), lesions with a maximal diameter <30mm (77.5% vs. 20.0%, P< 0.001), and vertebrobasilar system lesions (55.0% vs. 10.0%, P< 0.001) than the cardiogenic patients. CONCLUSIONS: Acute aortogenic embolic stroke is characterized by multiple (≥3) and small lesions, and involvement of the vertebrobasilar system.

Congenital left ventricular aneurysm coexisting with left ventricular non-compaction in a newborn.

Described herein is the case of a rare combination of congenital left ventricular (LV) aneurysm and left ventricular non-compaction (LVNC) in a newborn. The patient developed refractory heart failure soon after birth and died at 5 months of age. The etiology of both congenital LV aneurysm and LVNC seems to be maldevelopment of the ventricular myocardium during early fetal life. Treatment should be individually tailored depending on clinical severity, and treatment options are limited. Given that this combination of congenital LV aneurysm and LVNC is significantly associated with poor prognosis, it appears that patients with congenital LV aneurysm and LVNC are candidates for early, aggressive intervention, including surgical aneurysmectomy and evaluation for transplantation. It is important to be aware of this combination of congenital LV aneurysm and LVNC, and to make earlier decisions on therapeutic strategy.

Detecting groundwater level changes related to the 2016 Kumamoto Earthquake.

This study presented the first attempt to detect precursory changes in groundwater level before the 2016 Kumamoto Earthquake. This detection was achieved by accurately determining the relationship between long-term groundwater level fluctuation and crustal deformation over 16 years through analysis of groundwater level time-series data acquired at 17 sites within the study area. Here, we show that the observed groundwater levels were lower than the modelled levels in aquifers composed of porous strata (Togawa lava and part of the pre-Aso volcanic rocks), and that there were larger differences until 2014, which diminished until the occurrence of the Kumamoto Earthquake. The initial reduction in the modelled groundwater level and the latter recovery were most likely caused by crustal strain relaxation associated with the large 2011 earthquake off the Pacific coast of Tohoku (Mw 9.0) and the strain accumulation prior to the 2016 Kumamoto Earthquake.

Thoracoscopic esophagectomy with subcarinal lymph node dissection in the prone position for esophageal cancer with a right top pulmonary vein.

The right top pulmonary vein (RTPV), a rare pulmonary vein (PV) variant draining the right upper lobe, arises independently from the right superior PV, travels posterior to the right bronchial tree and drains directly into the left atrium (LA) or another PV. We report an RTPV discovered on preoperative computed tomography (CT) scanning in a 60-y-old man who subsequently underwent prone thoracoscopic esophagectomy and subcarinal lymph node dissection. The preoperative CT scan showed an anomalous vessel 7.8 mm in diameter arising from the right upper lobe, running posterior to the right main bronchus (RMB), and draining directly into the LA. To our best knowledge, this is the largest reported RTPV (7.8 mm in diameter) and is an extremely rare variant, passing posterior to the RMB and draining into the LA.

Early-onset Marfan syndrome with a novel missense mutation: A case report.

Early-onset Marfan syndrome (eoMFS) progresses rapidly, starting during the neonatal period, causes severe clinical disease, and has a poor prognosis. The genetic abnormality associated with eoMFS is located in a so-called critical neonatal region in exons 25-26 of the fibrillin-1 (FBN1) gene. A female neonate was delivered by emergency cesarean section at 37 weeks gestation due to fetal distress with bradycardia, cyanosis, and no spontaneous breathing. On examination, the patient had multiple musculoskeletal deformities, including loose redundant skin, arachnodactyly, flat soles, and joint contractures. Echocardiography showed poor cardiac contractility with multiple valvular abnormalities. She died 13 h after birth. We identified a novel missense variant c.3218A>G (p.Glu1073Gly) in exon 26 of the FBN1 gene by targeted next-generation sequencing. A literature review revealed that arachnodactyly and aortic root dilatation in the fetus are predictive of eoMFS. However, the predictive potential of ultrasonography alone is limited. Genetic testing of the FBN1 gene restriction region associated with short life expectancy and characteristic fetal ultrasound findings could be important for prenatal diagnosis of eoMFS, postnatal management, and parental preparedness. Learning objective: We identified a novel missense mutation located in exons 25-26 of the Fibrillin-1 gene in a neonate with early-onset Marfan syndrome (eoMFS) who died of severe early heart failure shortly after birth. This mutation was located in a narrowly defined critical neonatal region, recently reported to cause eoMFS, and its clinical profile was consistent with early-onset severe heart failure. In addition to ultrasonography, genetic analysis of this region is important for predicting prognosis in eoMFS.

Spring water quality and usability in the Mount Cameroon area revealed by hydrogeochemistry.

Groundwater is the only reliable water resource for drinking, domestic, and agricultural purposes for the people living in the Mount Cameroon area. Hydrogeochemical and R-mode factor analysis were used to identify hydrogeochemical processes controlling spring water quality and assess its usability for the above uses. Main water types in the study area are Ca-Mg-HCO(3) and Na-HCO(3). This study reveals that three processes are controlling the spring water quality. CO(2)-driven silicate weathering and reverse cation exchange are the most important processes affecting the hydrochemistry of the spring waters. While tropical oceanic monsoon chloride-rich/sulfate-rich rainwater seems to affect spring water chemistry at low-altitude areas, strong correlations exist between major ions, dissolved silica and the altitude of springs. In general, the spring waters are suitable for drinking and domestic uses. Total hardness (TH) values indicate a general softness of the waters, which is linked to the development of cardiovascular diseases. Based on Na %, residual sodium carbonate, sodium adsorption ratio, and the USSL classification, the spring waters are considered suitable for irrigation. Though there is wide spread use of chemical fertilizers and intense urban settlements at the lower flanks of the volcano, anthropogenic activities for now seem to have little impact on the spring water quality.

Nationwide survey for bisphosphonate-related osteonecrosis of the jaws in Japan.

PURPOSE: A nationwide retrospective cohort study was conducted by the Japanese Society of Oral and Maxillofacial Surgeons to assess the occurrence of bisphosphonate (BP)-related osteonecrosis of the jaws (BRONJ) during 2006 to 2008 and to elucidate the outcome and factors associated with remission of BRONJ. MATERIALS AND METHODS: A written questionnaire, including the clinical characteristics, management, and outcome of patients with BRONJ, was sent to 248 institutions certified as training facilities by the Japanese Society of Oral and Maxillofacial Surgeons in 2008. RESULTS: A total of 568 patients with BRONJ, including suspicious cases, were registered. Of these 568 patients, 263, including the maxilla in 81, the mandible in 160, and both in 22, met the working definition of BRONJ proposed by the American Association of Oral and Maxillofacial Surgeons. The patients included 219 women (83.3%) and 44 men (16.7%). Of these patients, 152 (57.8%) had received intravenous BPs, 104 (39.5%) had received oral BPs, and 7 (2.7%) had received both. The mean duration of administration until onset of BRONJ was 23.6 months for intravenous BPs and 33.2 months for oral BPs. BRONJ was stage 1 in 42 patients (16.0%), stage 2 in 187 (71.1%), stage 3 in 32 (12.2%), and unknown in 2. Of these patients, 34.2% had remission of BRONJ, 46.0% had persistent or progressive disease, and 19.7% died of malignancy or were lost to follow-up. Statistical analysis revealed that surgical treatment, including tooth extraction, sequestrectomy, and segmental mandibulectomy, contributed to the remission of BRONJ. In contrast, conservative treatment, concurrent anticancer drugs, poor oral hygiene, and the use of intravenous BPs did not. CONCLUSIONS: The relative ratio of BRONJ related to the use of oral BPs was greater in Japan than in the United States and European Union. Surgical treatment contributed to remission of BRONJ, and conservative treatment, concurrent anticancer drugs, poor oral hygiene, and intravenous BPs did not.

Pentazocine increases bispectral index without surgical stimulation during nitrous oxide-sevoflurane anesthesia.

Although there have been a large number of reports on the effects of opioids on the bispectral index (BIS) during anesthesia, the effects of pentazocine on the BIS have not been reported. In this study, 60 patients scheduled for elective oral surgery [30 females, 30 males; all American Society of Anesthesiologists Physical Status (ASA PS) category 1] were enrolled in the trials. Maintaining gender parity, we randomly assigned the patients to one of three groups: pentazocine group (0.3 mg/kg; n = 20), fentanyl group (1 µg/kg; n = 20), or saline group (n = 20); these opioids were administered intravenously 15 min after the intubation. Anesthesia was induced with thiopental and vecuronium bromide and maintained with nitrous oxide (4 l/min)-oxygen (2 l/min)-sevoflurane (1%). At 15 min after the intubation, mean arterial blood pressure (MAP), heart rate (HR), and BIS index were recorded as baseline values. MAP, HR, and BIS values were measured at 2.5-min after the intubation up to 30 min. All data were expressed as the mean ± standard deviation. Differences in BIS values, MAP, and HR among the three groups throughout the experiment were analyzed using two-way repeated-measures analysis of variance (ANOVA), and demographic data among the three groups were analyzed using one-way ANOVA. Post hoc comparisons were performed using Fisher's protected least significant difference test. A P value of <0.05 was considered to indicate statistically significance. MAP and HR showed no significant differences among the three groups during the study. BIS values significantly increased between 5 and 15 min after the intubation relative to the baseline value in the pentazocine group (P < 0.001), and BIS values in this group were significantly during this time period than those in the fentanyl and saline group (P < 0.001). BIS values were not significantly different between the fentanyl group and saline group. These results indicated that pentazocine, but not fentanyl, under nitrous oxide-sevoflurane anesthesia caused a statistically significant increase in BIS in our patients.

Evaluation of groundwater quality and its suitability for drinking, domestic, and agricultural uses in the Banana Plain (Mbanga, Njombe, Penja) of the Cameroon Volcanic Line.

Groundwater quality of the Banana Plain (Mbanga, Njombe, Penja-Cameroon) was assessed for its suitability for drinking, domestic, and agricultural uses. A total of 67 groundwater samples were collected from open wells, springs, and boreholes. Samples were analyzed for physicochemical properties, major ions, and dissolved silica. In 95% of groundwater samples, calcium is the dominant cation, while sodium dominates in 5% of the samples. Eighty percent of the samples have HCO(3) as major anion, and in 20%, NO(3) is the major anion. Main water types in the study area are CaHCO(3), CaMgHCO(3), CaNaHCO(3), and CaNaNO(3)ClHCO(3). CO(2)-driven weathering of silicate minerals followed by cation exchange seemingly controls largely the concentrations of major ions in the groundwaters of this area. Nitrate, sulfate, and chloride concentrations strongly express the impact of anthropogenic activities (agriculture and domestic activities) on groundwater quality. Sixty-four percent of the waters have nitrate concentrations higher than the drinking water limit. Also limiting groundwater use for potable and domestic purposes are contents of Ca(2+), Mg(2+) and HCO(3) (-) and total hardness (TH) that exceed World Health Organization (WHO) standards. Irrigational suitability of groundwaters in the study area was also evaluated, and results show that all the samples are fit for irrigation. Groundwater quality in the Banana Plain is impeded by natural geology and anthropogenic activities, and proper groundwater management strategies are necessary to protect sustainably this valuable resource.

[Effect of pentazocine on the bispectral index during nitrous oxide-sevoflurane anesthesia].

BACKGROUND: The effect of pentazocine on the bispectral index (BIS) has not been reported. In this study, we have examined whether pentazocine alters the bispectral index during nitrous oxide-sevoflurane anesthesia. METHODS: Thirty surgical patients were enrolled in this double-blind, randomized study. Anesthesia was induced with thiopental and vecuronium and maintained with nitrous oxide-sevoflurane with the bispectral index maintained at approximate 40. Under stable anesthetic condition before surgery, patients were assigned to receive either a bolus of pentazocine 0.3 mg x kg(-1), 0.6 mg x kg(-1) or the same volume of saline 15 min after induction. Blood pressure (BP), heart rate (HR) and BIS were measured every 2.5 min from 2.5 min before induction until 30 min after induction. RESULTS: BP and HR showed no changes after pentazocine administration compared with control group. BIS showed no significant change in the saline group, but it increased significantly in the pentazocine group. When pentazocine was administered 15 min after induction, BIS increased significantly 20, 22.5, 25, 27.5 and 30 min after induction compared with the control group. The increase of BIS by pentazocine showed no dose-dependent effect in our present study. CONCLUSIONS: We observed that intravenous pentazocine caused a significant increase in BIS under nitrous oxide-sevoflurane anesthesia. The depth of sedation should be assessed carefully using a bispectral index monitor when pentazocine is used together.

Simultaneous Expression of Th1- and Treg-Associated Chemokine Genes and CD4+, CD8+, and Foxp3+ Cells in the Premalignant Lesions of 4NQO-Induced Mouse Tongue Tumorigenesis.

Chemokines and cytokines in the tumor microenvironment influence immune cell infiltration and activation. To elucidate their role in immune cell recruitment during oral cancer development, we generated a mouse tongue cancer model using the carcinogen 4-nitroquinoline 1-oxide (4NQO) and investigated the carcinogenetic process and chemokine/cytokine gene expression kinetics in the mouse tongue. C57/BL6 mice were administered 4NQO in drinking water, after which tongues were dissected at 16 and 28 weeks and subjected to analysis using the RT2 Profiler PCR Array, qRT-PCR, and pathologic and immunohistochemical analyses. We found that Th1-associated chemokine/cytokine (Cxcl9, Cxcl10, Ccl5, and Ifng) and Treg-associated chemokine/cytokine (Ccl17, Ccl22, and Il10) mRNA levels were simultaneously increased in premalignant lesions of 4NQO-treated mice at 16 weeks. Additionally, although levels of Gata3, a Th2 marker, were not upregulated, those of Cxcr3, Ccr4, and Foxp3 were upregulated in the tongue tissue. Furthermore, immunohistochemical analysis confirmed the infiltration of CD4+, CD8+, and Foxp3+ cells in the tongue tissue of 4NQO-treated mice, as well as significant correlations between Th1- or Treg-associated chemokine/cytokine mRNA expression and T cell infiltration. These results indicate that CD4+, CD8+, and Foxp3+ cells were simultaneously recruited through the expression of Th1- and Treg-associated chemokines in premalignant lesions of 4NQO-induced mouse tongue tissue.

Mechanisms of resistance to interferon-gamma-mediated cell growth arrest in human oral squamous carcinoma cells.

Interferon-gamma (IFNgamma) has an antiproliferative effect on a variety of tumor cells. However, many tumor cells resist treatment with IFNs. Here, we show that IFNgamma fails to inhibit the growth of some types of oral squamous cell carcinoma (OSCC) cells that possess a fully functional IFNgamma/STAT1 (signal transducer and activator of transcription-1) signaling pathway. IFNgamma inhibited the growth of the HSC-2, HSC-3, and HSC-4 OSCC cell lines. However, Ca9-22 cells were resistant to IFNgamma despite having intact STAT1-dependent signaling, such as normal tyrosine phosphorylation, DNA binding activity, and transcriptional activity of STAT1. The growth inhibition of HSC-2 cells resulted from S-phase arrest of the cell cycle. IFNgamma inhibited cyclin A2 (CcnA2)-associated kinase activity, which correlated with the IFNgamma-mediated down-regulation of CcnA2 and Cdk2 expression at both the transcriptional and post-transcriptional level in HSC-2 cells but not in Ca9-22 cells. RNAi-mediated knockdown of CcnA2 and Cdk2 resulted in growth inhibition in both cell lines. These results indicate that the resistance of OSCC to IFNgamma is not due simply to the deficiency in STAT1-dependent signaling but results from a defect in the signaling component that mediates this IFNgamma-induced down-regulation of CcnA2 and Cdk2 expression at the transcriptional and post-transcriptional levels.

Type of cell death induced by various metal cations in cultured human gingival fibroblasts.

Metal ions are released from casting alloys and cause damage to cell structures and local inflammation. However, the cytotoxic mechanism and the type of cell death induced in human gingival fibroblast (HGF) by contact with dental metals have not been well characterized. Here the cytotoxicity of eight metals against HGF was investigated. Cytoxicity of metals against HGF was in the following order: Ag(NH(3))(2)F (most cytotoxic)>AgCl>CuCl(2)>CuCl, CoCl(2)> NiCl(2)>FeCl(2), FeCl(3) (least cytotoxic). None of the metals showed any apparent hormetic growth stimulation at lower concentrations, except for Ag(NH(3))(2)F at 20 or higher population-doubling level of HGF. The sensitivity of HGF against Ag(NH(3))(2)F was reduced during in vitro aging, similar to previous report with sodium fluoride. Contact with Ag(NH(3))(2)F for only one hour induced irreversible cell death, whereas longer duration of contact with AgCl or CuCl(2) was necessary to induce irreversible cell death. These metals induced neither DNA fragmentation nor caspase-3 activation. Pan-caspase inhibitor (Z-VAD-FMK) and autophagy inhibitors (3-methyladenine, bafilomycin) did not apparently affect the cytotoxicity of metals, when corrected for the effect of inhibitor alone on growth. We also found that Ag(NH(3))(2)F induced much higher cytotoxicity than AgCl in mouse osteoblastic cell line MC3T3-E1, possibly inducing necrosis. These data suggest the importance of cautious application of Ag(NH(3))(2)F to the oral cavity.

Effect of contact with titanium alloys on the proliferation of mouse osteoblastic cells in culture.

This study was aimed at studying the effect of contact with titanium alloy plates of different surface textures on the proliferative capability of mouse osteoblastic MC3T3-E1 cells. First, the proliferation characteristics of MC3T3-E1 cells were investigated. MC3T3-E1 cells showed a high capacity for proliferation and survived for a long period even under nutritionally starved conditions. During logarithmic cell growth, the consumption of Ser, Gln, Val, Ile and Leu increased time-dependently. Contact with an hydoxyapatite (HA)-coated titanium alloy plate resulted in the increase in the recovery of cells from the plate by trypsin, and an increase in the consumption of these amino acids, suggesting enhanced cell proliferation. On the contrary, contact with the sandblasted and anodized titanium alloy plates resulted in the reduction of the recovery of the cells from the plate, but a slight increase in the amino acid consumption, suggesting the tight adhesion of the cells to the plates. This study demonstrates that the present method, based on the amino acid consumption of the cells, is useful for monitoring the cell proliferative capability, without detachment of the cells from the plate. This method may be applicable to the study of the interaction between cells and metal plates.