Attitudes toward smoking cessation according to smoking status among dentists in the Aichi Dental Association in Japan.

INTRODUCTION: The prevalence of smoking, including heated tobacco products (HTPs), among Japanese dentists was reported to be 16.5%, significantly higher than that among Japanese physicians and United States dentists. However, large-scale studies on smoking cessation implementation based on dentists' smoking status and perceptions since the introduction of HTPs are lacking. Therefore, we aimed to investigate and assess dentists' attitudes toward smoking, including HTP use and smoking cessation, according to smoking status. METHODS: A self-administered questionnaire comprising six major items was mailed to 3883 dentists who were members of the Aichi Dental Association in August 2019. The primary outcome was smoking cessation status. The secondary outcome was the impact of smoking on intervention for smoking cessation. This study was reported using the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. RESULTS: Among the 1317 (42%) dentists analyzed, men were more positive toward smoking than women. Current and former smokers were more positive about smoking than never smokers/users, regardless of the tobacco product type. Additionally, the current smoker group using conventional cigarettes was less likely to ask for their patients' smoking status than the never smoker group. Furthermore, the current smoker (OR=2.0; 95% CI: 1.3-3.1 vs never smoker) and HTP user (OR=1.9; 95% CI: 1.2-3.1 vs never user) groups were less likely to engage in smoking cessation than the never smoker/user groups, regardless of the tobacco product type. CONCLUSIONS: Since the smoking status of dentists affects the implementation of smoking cessation interventions, it is crucial to encourage them to quit using all tobacco products to promote smoking cessation interventions in dental practice. Additionally, providing proper smoking prevention education to dentists is an important task.

Role of naofen in apoptosis of hepatocytes induced by lipopolysaccharide through mitochondrial signaling in rats.

AIM: Lipopolysaccharide (LPS) causes apoptosis of hepatocytes, which is probably mediated by inflammatory substances released from Kupffer cells (KCs). Recently, we have reported that naofen, a newly found intracellular WD40-repeat protein, has a role in inducing the apoptosis in HEK293 cells. Hence, the present study was undertaken to investigate a role of naofen in the LPS-induced apoptosis of rat hepatocytes. METHODS: Rats were treated with i.v. injections of LPS, and livers were extirpated to evaluate expression of naofen and apoptosis. In in vitro experiments, hepatocytes and KCs were separately isolated from rat livers. The incubation medium for KCs treated with LPS (KC-CM) was used for hepatocyte culture. RESULTS: Intravenous injections of LPS enhanced the expression of naofen in the livers. Livers showed terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive staining, and elevated caspase-3 activity. In isolated KCs or hepatocytes, LPS hardly affected naofen expression and caspase-3 activity, whereas incubation of hepatocytes with KC-CM enhanced both naofen expression and caspase-3 activation. Transfection of hepatocyte with naofen siRNA prevented such effects of KC-CM, and clearly eliminated KC-CM-induced reduction of Bcl-2 and Bcl-xL. In contrast, overexpression of naofen in hepatocytes downregulated Bcl-2 and Bcl-xL, released cytochrome c from mitochondria, and activated caspase-3. CONCLUSION: These results indicate that LPS may induce the hepatic apoptosis in association with enhanced naofen expression, and that naofen may mediate the activation of caspase-3 through downregulating the Bcl-2 and Bcl-xL expression, and releasing cytochrome c from mitochondria to cytoplasm.

Effects of 1-O-hexyl-2,3,5-trimethylhydroquinone on carbon tetrachloride-induced hepatic cirrhosis in rats.

AIM: The present study was undertaken to evaluate the effects of 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ), a synthesized vitamin E derivative, on carbon tetrachloride (CCl(4))-induced cirrhosis. METHODS: Rats were treated with hypodermic injections of CCl(4) twice a week to induce the hepatic cirrhosis, and given drinking water containing HTHQ or solvent. Primary cultures of rat hepatocytes were performed to evaluate the effects of HTHQ on the expression of inducible nitric oxide synthase (iNOS). RESULTS: Masson's staining of rat livers showed fibrosis around pseudo-lobules in the CCl(4) group, the lesions being reduced in the CCl(4) HTHQ group. Increases in liver tissue hydroxyproline and alpha(1)(I) collagen, alpha-smooth muscle actin and iNOS induced by CCl(4), were also markedly diminished by HTHQ. Furthermore, both HTHQ and vitamin E attenuated interleukin-1beta-induced iNOS protein expression in cultured hepatocytes, the potency of HTHQ being 10-times higher than that of vitamin E. CONCLUSION: HTHQ may inhibit development of hepatic cirrhosis in rats, more potently than vitamin E, by inhibiting the iNOS expression in hepatocytes. Because vitamin E has a radical scavenging action, roles of NO and peroxynitrite will be discussed in the effects of HTHQ on the fibrosis.

Naofen, a novel WD40-repeat protein, mediates spontaneous and tumor necrosis factor-induced apoptosis.

Naofen has recently been identified from the rat brain/spinal cord cDNA library as a substance reactive against an anti-shigatoxin (Stx)-2 antibody. Naofen mRNA is composed of 4620 nucleotides and encodes 1170 amino acids. Naofen contains four WD-repeat domains in its N-terminus and is ubiquitously distributed in many tissues of the rat. Tumor necrosis factor (TNF)-alpha enhanced the expression of naofen mRNA in HEK293 cells in a dose-dependent manner. Furthermore, naofen siRNA, which predominantly knocked down the expression of naofen mRNA, significantly reduced both TNF-alpha-induced caspase-3 activation and apoptosis in HEK293 cells. Overexpression of naofen in HEK293 cells (FLAG-NF) spontaneously induced caspase -3 activation and apoptosis, and showed extremely high susceptibility to TNF-alpha-induced apoptosis. These results indicated that naofen may function as a novel modulator activating caspase-3, and promoting TNF-alpha-stimulated apoptosis.

Roles of naofen, a novel WD-repeat-2 protein, in the CCl4-treated livers--a possible relationship to cell proliferation.

Naofen (GenBank accession no. EF613262), a newly found intracellular protein in the WD-repeat-2 protein family, has been cloned as an anti-verotoxin II antibody immunoreactive substance, and the nucleotide- and amino acid-sequences have been clarified. The present study was undertaken to evaluate the roles of naofen especially in carbon tetrachloride (CCl4-induced cirrhosis model of rats, also in partial hepatectomy. Naofen mRNA expressions were observed from the early phases of cirrhosis development and during regenerative phases after partial hepatectomy, more remarkable in the former. Naofen immunoreactive fragments located in the vascular endothelial cells and peri-vascular spaces in normal livers especially in Glisson's areas, being strongly stained in the connective tissues 8 weeks after starting CCl4-injections, besides in the cytoplasm of hepatocytes in pseudo-lobules. In contrast, partial hepatectomy caused a small increase of naofen expressions in the whole hepatocytes, and significantly in the endothelial cells of portal veins and hepatic arterioles. Furthermore, in parallel to the degree of naofen mRNA and protein expressions, the rates of double-nuclei cells to total hepatocytes in the Glisson's areas increased in both cirrhosis and partial hepatectomy, suggesting a relationship between naofen expression and mitosis. In in-vitro studies with cell lines, vascular endothelial growth factor, a cell proliferation stimulant, increased the naofen mRNA expressions in HepG(2) cell lines, whereas paclitaxel, a cytotoxic anti-cancer drug, diminished them in NRK52E, both concentration-dependently. These results indicated that naofen immunoreactive fragments play an important role in the cell proliferation, relevant for analyzing the regenerative phases during cirrhosis developments and after partial hepatectomy.

Relationship between serum concentrations of saturated fatty acids and unsaturated fatty acids and the homeostasis model insulin resistance index in Japanese patients with type 2 diabetes mellitus.

BACKGROUND: Consumption of polyunsaturated fatty acids (PUFA) improves the lipid metabolism of diabetics, leading to prevents of arteriosclerosis. Exact relationship between saturated fatty acids (SFA) or PUFA and the insulin resistance of diabetics are unknown. SUBJECTS AND METHODS: We investigated the relationship between the serum concentrations of saturated and unsaturated fatty acids and the homeostasis model insulin resistance index (HOMA-R) in Japanese patients with type 2 diabetes mellitus. RESULTS: The SFA, i.e., lauric acid, myristic acid, palmitic acid, and stearic acid; the monounsaturated fatty acids (MUFA), i.e., palmitoleic acid, oleic acid, and erucic acid; and the PUFA, i.e., eicosadienoic acid, dihomo-gamma-linolenic acid, docosatetraenoic acid, and docosapentaenoic acid were positively correlated with HOMA-R. However, no correlations were found between HOMA-R and SFA, i.e., arachidic acid, behenic acid, and lignoceric acid; the MUFA, i.e., eicosenoic acid and nervonic acid; and the PUFA, i.e., linoleic acid, gamma-linolenic acid, linolenic acid, 5-8-11 eicosatrienoic acid, arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid. CONCLUSIONS: Some PUFA as well as SFA were positively correlated with HOMA-R. These results indicate that the intake of diet fatty acid must be well balanced in diabetic patients and it is not always true to refrain from taking SFA and increase the unsaturated fatty acids in their diets.

Activity of gelatins to induce secretion of a variety of cytokines from murine peritoneal exudate macrophages.

Previously, we observed that liquid form bovine bone (BB) gelatin stimulates murine spleen cells to proliferate in vitro. In this study, activity of BB gelatin to stimulate murine-adherent peritoneal exudate cells (PEC) to secrete cytokines has been examined. Quantitatively, BB gelatin stimulated adherent PEC of C3H/HeN mice to secrete interleukin (IL)-12 (+p40), TNF-alpha, and IL-6 but not IL-1beta, IL-2, IL-10, and IFN-gamma. Qualitatively, BB gelatin-induced secretion of KC, MIP-2, MCP-1, RANTES, and MIP-1a as well as IL-6 but not 6Ckine, CTACK, Eotaxin, G-CSF, GM-CSF, IL-2,-3,-4,-5,-9,-10,-12,-13,-17, Leptin, IFN-gamma, SCF, sTNFri, TARC, TNF-alpha, TIMP-1, Tpo, and VEGF. BB gelatin acted on adherent PEC of C3H/HeN mice but not C3H/HeJ mice, which lack Toll-like receptor 4. Polymyxin B, a LPS antagonist, did not inhibit the activity of BB gelatin. Lipopolysaccharide (LPS) but not BB gelatin induced secretion of an appreciable amount of mIL-1beta. These results suggest that the activity of BB gelatin is not attributed to contamination of LPS but BB gelatin itself. It was also suggested that BB gelatin stimulated adherent PEC to newly produce and secrete cytokines.

Effect of gelatins on human cancer cells in vitro.

Three types of gelatins were tested for their antiproliferative activities in vitro against three human tumor cell lines (K-562; erythroleukemia, HCT-15; colon carcinoma, AGS; gastric carcinoma) with viable cell count and tritium-thymidine ((3)H-TdR) uptake by those cells. Porcine skin (PS) gelatin exerted the strongest antiproliferative activity of all three gelatins. Bovine bone (BB) gelatin did not exert such an activity. PS gelatin exerted antiproliferative activity against K-562 cells also in a serum-free medium. The serum-free medium contains two growth factors, insulin and transferrin, as well as nutrients. The activity of PS gelatin was not interfered by addition of insulin and transferrin to the medium. Effect of diluting a K-562 cell-concentration on the activity of PS gelatin was tested. Diluting the cell concentration did not affect the activity of PS gelatin. Moreover, the conditioned medium in which K-562 cells had been cultured did not stimulate the proliferation of K-562 cells. In conclusion, PS gelatin suppress the proliferation of human tumor cell lines in vitro. The antiproliferative activity of PS gelatin might not be attributed to trapping growth factors or autocrine mediators.

Comparison between bovine bone and porcine skin gelatins in their effects on murine cell proliferation.

We investigated relationship between porcine skin (PS) and bovine bone (BB) gelatins in their actions on proliferation of murine benign and malignant cells in this study. We previously observed that BB gelatin enhanced spleen cell proliferation. The present study showed that such an activity of BB gelatin was not exerted in a serum-free medium. On the other hand, PS gelatin suppressed proliferation of normal spleen cells and of those stimulated by concanavalin A (Con A). It is not known whether or not such an activity of PS gelatin on Con A-stimulated spleen cells is exerted in the serum-free medium since Con A was unable to augment proliferation of spleen cells in that medium. BB gelatin as well as PS gelatin suppressed proliferation of RL male symbol 1 cells, a T cell lymphoma cell line of Balb/c mice, and such an activity of BB gelatin was not exerted in the serum-free medium whereas PS gelatin exerted its activity in the same medium. Mitomycin C (MMC)-treated spleen cells as well as MMC-treated RL male symbol 1 cells partly released RL male symbol 1 cells from the inhibition of proliferation by PS gelatin. MMC-treated RL male symbol 1 cells as well as MMC-treated spleen cells suppressed the proliferation of spleen cells augmented by BB gelatin. Inhibition of RL male symbol 1 cell proliferation by PS gelatin was not affected by BB gelatin, but enhancement of spleen cell proliferation by BB gelatin was attenuated by PS gelatin regardless of the sequence of treating the spleen cells with PS gelatin. Enhancement of spleen cell proliferation by BB gelatin was time-dependent but suppression of RL male symbol 1 cell proliferation by PS gelatin was not. In conclusion, BB gelatin enhanced proliferation of spleen cells and suppressed proliferation of RL male symbol 1 cells. In both cases, fetal calf serum (FCS) was required. PS gelatin suppressed proliferation of spleen cells and of RL male symbol 1 cells without FCS.