Evaluation of Stain Penetration by Beverages in Demineralized Enamel Treated With Resin Infiltration.

PURPOSE: To evaluate stain penetration by different beverages in artificially demineralized human teeth treated with resin infiltration. METHODS AND MATERIALS: Sixty extracted human permanent molars were demineralized, treated with resin infiltration (Icon), and immersed in four different beverages (coffee, grape juice, iced tea, and distilled water; N=15) for four weeks. After aging, teeth in the distilled water group were stained with 2% methylene blue for 24 hours. All teeth were sectioned, and stain penetration was evaluated under light microscopy. Chi-square test, independent and paired sample t-test, analysis of variance with the Fisher least significant difference post hoc test, and the Kruskal-Wallis test were used to analyze the results (p<0.05). RESULTS: Resin infiltration-treated surfaces (Icon surfaces) had statistically significant fewer samples with presence of stain penetration compared to untreated surfaces (control surfaces) (p<0.001). There was also a significant decrease in depth of stain penetration in Icon surfaces compared to the control surfaces (p<0.001). Among tested beverage groups, iced tea showed significantly greater depth of stain penetration (0.134±0.029 mm), followed by grape juice (0.118±0.047 mm), methylene blue (0.022±0.019 mm), and coffee (0.008±0.017 mm; p<0.001). CONCLUSION: Both Icon and control surfaces exhibit stain penetration by different beverages (iced tea, grape juice, and coffee). However, resin-infiltrated enamel surfaces allow significantly less depth of stain penetration compared to untreated surfaces. The iced tea group presents greatest depth of stain penetration, followed by grape juice, methylene blue, and coffee.

Protective effects of sodium p-aminosalicylic acid on learning and memory via increasing the number of basal forebrain choline acetyltransferase neurons in manganese-exposed rats.

This study was conducted to investigate the protective effects of sodium p-aminosalicylic acid (PAS-Na) on learning and memory via increasing the number of basal forebrain choline acetyltransferase (ChAT) neurons in manganese (Mn)-exposed rats. Male Sprague Dawley rats were divided into following groups: the normal control I, II, and III groups, the model I, II, and III groups, low- and high-dose PAS-Na treatment (L- and H-PAS) group, PAS-Na prevention (PAS-P) group, and PAS-Na treatment (PAS-T) group. The model I, II, and III groups, L- and H-PAS, and PAS-T groups received intraperitoneal (i.p.) injection of 15 mg/kg manganese chloride tetrahydrate (MnCl2·4H2O) for 3 or 12 weeks, while the normal control I, II, and III groups received i.p. injection of an equal volume of saline; L- and H-PAS and PAS-T groups received back subcutaneous (s.c.) injection of PAS-Na (100 and 200 mg/kg) for the next 5 or 6 weeks, whereas model I and II group received back s.c. injection of an equal volume of saline. However, PAS-P group received back s.c. injection of 200 mg/kg PAS-Na + i.p. injection of 15 mg/kg MnCl2·4H2O for 12 weeks. Mn exposure significantly reduced the ability of spatial learning and memory capability, while PAS-Na prevention recovered it. Mn decreased the number of ChAT-positive neurons in vertical limb nucleus of the basal forebrain diagonal band/horizontal limb nucleus of the basal forebrain diagonal band and ChAT protein activity and treatment or prevention with PAS-Na restored those comparable with control. In brief, our results showed that PAS-Na may have protective effects on learning and memory against Mn via increasing the number of ChAT-positive neurons and activity of ChAT protein.

Devolopmental and growth temperature regulation of omega-3 fatty acid desaturase genes in safflower (Carthamus tinctorius L.).

Three ω-3 fatty acid desaturase genes (CtFAD3, CtFAD7, and CtFAD8) were isolated from safflower (Carthamus tinctorius L.). Transcript analysis showed that the highest transcript levels were detected for CtFAD3 and the low transcript levels were detected for CtFAD7 and CtFAD8 in flowers. This result indicates that CtFAD3 enzyme activity is important for fatty acid desaturation in flowers. The low transcript level of CtFAD3 in developing seeds was consistent with the recorded high level of linoleic acid (18:2) and lack of linolenic acid (18:3) in safflower seed oil. At low temperatures, the induced transcription levels of ω-3 fatty acid desaturase genes in the stems and petioles were consistent with increased polyunsaturated fatty acids (PUFAs). In the roots, ω-3 fatty acid desaturase noticeably increased at low temperatures, whereas PUFA levels decreased. Interestingly, C18:3(Δ9,12,15) alcohol was specifically found in safflower roots, and showed a significant increase, indicating a flux in the acid to alcohol ratio of this compound in safflower roots.

Salvia miltiorrhiza inhibits intimal hyperplasia and monocyte chemotactic protein-1 expression after balloon injury in cholesterol-fed rabbits.

Antioxidants that prevent low density lipoproteins (LDL) from oxidation may inhibit atherosclerosis and post-angioplasty restenosis. Salvia miltiorrhiza (SM) has been shown to inhibit LDL oxidation and reduce atherosclerosis in cholesterol-fed rabbits. The effects of SM on neointimal hyperplasia and monocyte chemotactic protein-1 (MCP-1) expression after balloon injury were studied. Male New Zealand white rabbits were fed a 2% cholesterol diet together with daily SM (4.8 gm/kg body wt.) treatment (SM; n=10) or without SM as a control (C; n=9) for 6 weeks. Probucol-treated (0.6 gm/kg body wt.) rabbits (P; n=9) were used as a positive control group. A balloon injury of the abdominal aorta was performed at the end of the third week. Aortas were harvested at the end of 6 weeks. The plasma cholesterol levels were lowered in SM group. The neointimal hyperplasia in abdominal aortas was significantly inhibited in SM group [neointima/media area ratio: 0.63+/-0.05 (SM) versus 0.78+/-0.05 (C); P < 0.05] and in P group [0.45+/-0.02 (P) versus 0.78+/-0.05 (C); P < 0.05] when compared with C group. SM treatment significantly reduced MCP-1 mRNA and protein expression in balloon-injured abdominal aorta. These inhibitory effects on intimal response after balloon injury might be attributed to antioxidant capacity and cholesterol lowering effect of SM. SM treatment may offer some protection against post-angioplasty restenosis.

Salvianolic acid B attenuates VCAM-1 and ICAM-1 expression in TNF-alpha-treated human aortic endothelial cells.

Attachment to, and migration of leukocytes into the vessel wall is an early event in atherogenesis. Expression of cell adhesion molecules by the arterial endothelium may play a major role in atherosclerosis. It has been suggested that antioxidants inhibit the expression of adhesion molecules and may thus attenuate the processes leading to atherosclerosis. In the present study, the effects of a potent water-soluble antioxidant, salvianolic acid B (Sal B), and an aqueous ethanolic extract (SME), both derived from a Chinese herb, Salvia miltiorrhiza, on the expression of endothelial-leukocyte adhesion molecules by tumor necrosis factor-alpha (TNF-alpha)-treated human aortic endothelial cells (HAECs) were investigated. When pretreated with SME (50 and 100 microg/ml), the TNF-alpha-induced expression of vascular adhesion molecule-1 (VCAM-1) was notably attenuated (77.2 +/- 3.2% and 80.0 +/- 2.2%, respectively); and with Sal B (1, 2.5, 5, 10, and 20 microg/ml), 84.5 +/- 1.9%, 78.8 +/- 1.2%, 58.9 +/- 0.4%, 58.7 +/- 0.9%, and 57.4 +/- 0.3%, respectively. Dose-dependent lowering of expression of intercellular cell adhesion molecule-1 (ICAM-1) was also seen with SME or Sal B. In contrast, the expression of endothelial cell selectin (E-selectin) was not affected. SME (50 microg/ml) or Sal B (5 microg/ml) significantly reduced the binding of the human monocytic cell line, U937, to TNF-alpha-stimulated HAECs (45.7 +/- 2.5% and 55.8 +/- 1.2%, respectively). SME or Sal B significantly inhibited TNF-alpha-induced activation of nuclear factor kappa B (NF-kappaB) in HAECs (0.36- and 0.48-fold, respectively). These results demonstrate that SME and Sal B have anti-inflammatory properties and may explain their anti-atherosclerotic properties. This new mechanism of action of Sal B and SME, in addition to their previously reported inhibition of LDL, may help explain their efficacy in the treatment of atherosclerosis.

Interaction between protein kinase C and sphingomyelin/cholesterol.

Physical characteristics of binding of protein kinase C with sphingomyelin/cholesterol lipid bilayers were analysed using three complementary approaches: acrylodan fluorescence, fluorescence energy transfer and quenching of tryptophan fluorescence. It was demonstrated that sphingomyelin/cholesterol lipid membranes were available for protein kinase C binding. The intensity of the binding was dependent on the sphingomyelin content. The results of quenching of intrinsic tryptophan fluorescence showed that the enzyme molecule penetrated the sphingomyelin/cholesterol lipid bilayer to the C-16 position of labeled fatty acid probes. Our results also showed sphingomyelin itself restrains protein kinase C activity. A possible explanation for our results is that caveolae function as signaling storage devices.

A study on betel quid chewing behavior among Kaohsiung residents aged 15 years and above.

A telephone survey was used to study betel quid chewing behavior of Kaohsiung residents aged 15 and above in early 1991. Among the 1,162 subjects, 154 (13.3%) reported that they chewed betel quids and most of them (145/154) were men. Among the chewers, 33 (21.4%) indicated that they chewed it daily; all were men. Age distribution of the chewing behavior suggested that more young people chewed it at the time of the survey than had been the case in the past. The demographic distributions of betel quid chewing behavior were similar to the characteristics of tobacco smoking in Taiwan. The degree of concurrence of these two behaviors was very high. Nearly 90% of the subjects believed that betel quid chewing would cause more harm than good, or it would cause only harm, to their health. Discriminant analyses indicated that smoking behavior and attitude toward the health effect of chewing betel quids were the two most significant and meaningful variables in prediction of the chewing behavior. Strategies for prevention are recommended.

Experimental and clinical studies on the reduction of erythrocyte sorbitol-glucose ratios by ascorbic acid in diabetes mellitus.

In order to confirm the effect of ascorbic acid (AA) on human erythrocyte sorbitol accumulation and explore its mechanism of action, the effects of ascorbic acid in vitro on the sorbitol (S) and glucose (EG) content of human erythrocytes and in particular on the S/EG ratio as a marker of aldose reductase (AR) activity were carefully observed. The results showed that both the accumulation of erythrocyte sorbitol and the S/EG ratio were strongly reduced by the addition of AA. The sorbitol content in the erythrocyte and the S/EG ratio were reduced by a maximum of 87.3% and 83.4% and 93.8% and 63.9% when the medium's AA concentration was at its peak with 5.6 mmol/l and 28 mmol/l glucose in the medium, respectively. The contents of erythrocyte glucose measured coincidentally revealed a positive correlation with the ascorbic acid concentration in the medium during incubation in 5.6 mmol/l glucose while at a higher glucose level (28 mmol/l) in the medium the correlation became negative. These results suggested that the polyol pathway could be inhibited effectively by AA through its direct action on AR. The results of a double-blind cross-over trial using AA tablets or inositol tablets in eight diabetic patients showed that the supplementation of 1000 mg AA/day for 2 weeks resulted in reductions of 12.2% and 21.8% in erythrocyte sorbitol and red cell sorbitol/plasma glucose (S/PG) ratio, respectively (P < 0.05), whereas the fasting plasma glucose levels measured coincidentally revealed no changes (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Ilexonin A on circulatory neuroregulation.

Ilexonin A (IA), a pentacyclic triterpene, has been semisynthesized in china for the first time. It is extracted from the root of Ilicis pubescentis, a commonly used herbal medicine in Guangdong for the treatment of cardiovascular, cerebrovascular and peripheral vascular diseases and heart failure with satisfactory effects. The pharmacokinetic studies indicated that the elimination half-life after oral and i.v. dosing were 17.7 +/- 2.4 h and 22.5 +/- 2.9 h respectively. The total clearance was 4.6 +/- 0.51/h. The bioavailability of IA capsules was 0.39 +/- 0.14 and LD50 was 234 mg/Kg. We have adopted modern techniques, including cellular electrophysiology, isotope tracing methods, molecular biology, electromicroscopy, etc., to probe into the pharmacologic mechanisms of the effects of IA on cardiovascular system. The results indicated that IA can increase the contractility of isolated guinea pig auricular myocardium, attenuate vascular smooth muscle tension induced by noradrenaline in the rabbit aorta. IA can exert a biphasic regulatory effect on arterial blood pressure. IA also can prolong A-V duration of Hiss bundle electrograph (HBE) in rabbits and prolong the action potential duration and the effective refractory period (ERP) of myocardial cells in guinea pigs. The results showed that IA can increase the cAMP content in the smooth muscle of aorta and exert a calcium-blockade effect. Therefore, the peripheral resistance vessels are relaxed and the cardiac afterload is lowered. IA-blocked calcium channels are correlated with both the potential-dependent channel and the receptor operated channel in vascular smooth muscles. IA also increases the cAMP content of myocardium and accelerates the cellular calcium influx and efflux, and this may be responsible for the direct mechanism of the positive inotropic action of IA. Under electron microscopy, it is observed that IA can alleviate the defect of succinate dehydrogenase in the myocardial mitochrondria of rabbit chronic congestive heart failure (CF) model and reduce the microstructural damage of the failed myodardium, therefore the anoxic tolerance of myocardium is increased, the effect of IA on the platelet stretching activity and microstructure in the patients with CF is also studied. It is found that IA can reduce the hypercoagulability of blood, decrease the severity of blood stagnation and improve the status of microcirculation. Effects of IA introventricular and cardiovascular central microinjection (nucleus tractus solitarius, paraventricular nucleus) on arterial blood pressure and heart rate were studied. It demonstrated that IA possess circulatory neuroregular effects by the medium of alpha-receptor and beta-receptor of cardiovascular motoneurons.

[Sequential observation on the influence of artificial wind-cold environment to immunologic function of mononuclear phagocytic system in mice].

According to TCM theory of Six Evils, the Wind-Cold is one of the pathogen. In order to find the mechanism of Wind-Cold in causing disease, the effect of subacute Wind-Cold stimulation on the phagocyte immunization in mice was observed. Results showed that through exposing in the Wind-Cold environment, the reticuloendothelial system (RES) clearance function and the hydrogen-peroxide releasing of peritoneal macrophage were suppressed. Sequential observation showed that the peak of immunosuppression occurred on the 3rd day after stimulation and began to normalize at 5th day. These results suggested that Wind-Cold stimulation could inhibit temporary phagocytosis of macrophage and bacteriocidal effect. Action of immunosuppression was believed to be produced by the increase of stress hormone after stimulation. Results also suggested that the pathogenic action of Wind-Cold on disease is somewhat related with the suppression of nonspecific cellular immunity.

Anisodamine causes acyl chain interdigitation in phosphatidylglycerol.

The effect of anisodamine on the structure of the gel phase and the properties of the acyl chain disordering transition of dipalmitoylphosphatidylglycerol (DPPG) has been studied through high-sensitivity differential scanning calorimetry (DSC) and fluorescence polarization measurements of 16-(9-anthroyloxyl)-palmitic acid (16AP) and 3-(9-anthroyloxyl)-stearic acid (3AS), labeling, respectively, the ends and the third carbon of the acyl chains. The non-interdigitated DPPG multilamellar vesicles formed in HEPES buffer show clear fluidity gradient in their acyl chains, whereas the fluidity gradients are completely abolished in the presence of anisodamine. The DSC results showed that the phase transition temperature (Tm) of DPPG is decreased and the enthalpy (delta H) is increased by anisodamine, while the pre-transition vanishes. At 3 mM anisodamine, the delta H of DPPG reaches 9.6 kcal/mol. It can be concluded that DPPG forms an interdigitated gel phase in the presence of anisodamine. A molecular scheme for the interaction of anisodamine with DPPG is proposed.

[Effects of Rhizoma Ligustici chuanxiong and allopurinol on ischemia-reperfusion damage of rabbit ear flap].

The effect of Rhizoma Ligustici Chuanxiong and allopurinol on ischemia-reperfusion damage of rabbit ear flap was studied. The results showed that MDA level was higher and SOD activity lower distinctly at 0.5 hour after reperfusion than that at 16 hours of postischemia and preischemia, Rhizoma Ligustici Chuanxiong and allopurinol changed the result markedly with a decrease of necrosis rate. The effect of Rhizoma Ligustici Chuanxiong was more significant than that of allopurinol in promoting microcirculation, preventing clot formation, reducing exudation and hemorrhage.

[Comparison of nicardipine and nifedipine in treatment of Chinese senile hypertension placebo-control, double-blind, randomized and crossover study].

The purpose of this placebo-control, double-blind, randomized and crossover study is to evaluate the effect of nicardipine and nifedipine in Chinese senile hypertension. Among totally 37 senile hypertensive patients enrolled, 26 patients (25 males, 1 female) from 55 to 78 years of age (mean 65) who had finished one part or whole protocol were studied. Totally 18 cases after 6-week treatment of nicardipine (Perdipine) had blood pressure decrease significantly from 152.6 +/- 12.3/99.6 +/- 5.7 to 140.4 +/- 15.6/93.8 +/- 8.1 mmHg in supine position (P < 0.05), and from 153.3 +/- 12.7/98.7 +/- 7.7 to 139.2 +/- 13.5/90.7 +/- 7.6 mmHg in standing position (p < 0.05). Twenty-five cases after 6-week treatment of nifedipine (Towarat) also had significant blood pressure decrease from 155.0 +/- 13.3/99.5 +/- 8.4 to 144.2 +/- 10.0/95.3 +/- 9.2 mmHg in supine position (P < 0.05), and from 151.5 +/- 17.8/100.6 +/- 9.5 to 138.6 +/- 12.8/90.4 +/- 8.3 mmHg in standing position (p < 0.05). Heart rate was unchanged in both groups. Both nicardipine and nifedipine decreased blood pressure and increased heart rate significantly with the first dose of medication in the morning (P < 0.05). There was 6.5% and 9.0% decrease of systolic and diastolic blood pressure with nicardipine in supine position, 10.1% and 11.2% decrease with nifedipine in supine position, 6.3% and 7.2% decrease with nicardipine in standing position, and 9.7% and 10.6% decrease with nifedipine in standing position. The major side-effects were palpitation (20%) and lower abdominal distension (16%) with nicardipine; and nausea or vomiting (22%) and dizziness (15%) with nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of thyroxine and methimazolum on monamine transmitters in preoptic/anterior hypothalamic area and peripheral serum in rats].

The contents of monamine transmitters in preoptic/anterior hypothalamic (PO/AH) area and in the serum of rats injected with thyroxine (T4, 1 mg/100 g body wt/d, for 10 d, hypodermic i.) and fed with methimazolum (10 mg/100 g body wt/d, for 15 d) were assayed by high pressure liquid chromatography with electrochemical detector (HPLC-ECD). It was found that the content of dopamine and homovanillic acid in PO/AH area showed significant increase (P less than 0.01) associated with a slight rise (P greater than 0.05) of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA), and with no change of norepinephrine in the thyroxine group. After fed with methimazolum, the content of norepinephrine decreased significantly (P less than 0.05), but no obvious changes occurred in dopamine, homovanillic acid, 5-HT and 5-HIAA. By synchronous analysing of monamine transmitters in peripheral serum, it was showed that there was no significant linear relationship between the changes of monamine transmitters in the brain and in the serum. The correlation between thyroxine and methimazolum on the content of monamine transmitters and on the change of body temperature was also discussed.

Specificity of attenuation control in the ilvGMEDA operon of Escherichia coli K-12.

Three different approaches were used to examine the regulatory effects of the amino acids specified by the peptide-coding region of the leader transcript of the ilvGMEDA operon of Escherichia coli K-12. Gene expression was examined in strains carrying an ilvGMED'-lac operon fusion. In one approach, auxotrophic derivatives were starved of single amino acids for brief periods, and the burst of beta-galactosidase synthesis upon adding the missing amino acid was determined. Auxotrophic derivatives were also grown for brief periods with a limited supply of one amino acid (derepression experiments). Finally, prototrophic strains were grown in minimal medium supplemented with single and multiple supplements of the chosen amino acids. Although codons for arginine, serine, and proline are interspersed among the codons for the three branched-chain (regulatory) amino acids, they appeared to have no effect when added in excess to prototrophs or when supplied in restricted amounts to auxotrophs. Deletions removing the terminator stem from the leader removed all ilv-specific control, indicating that the attenuation mechanism is the sole mechanism for ilv-specific control.

A Rhizobium leguminosarum mutant defective in symbiotic iron acquisition.

Iron acquisition by symbiotic Rhizobium spp. is essential for nitrogen fixation in the legume root nodule symbiosis. Rhizobium leguminosarum 116, an ineffective mutant strain with a defect in iron acquisition, was isolated after nitrosoguanidine mutagenesis of the effective strain 1062. The pop-1 mutation in strain 116 imparted to it a complex phenotype, characteristic of iron deficiency: the accumulation of porphyrins (precursors of hemes) so that colonies emitted a characteristic pinkish-red fluorescence when excited by UV light, reduced levels of cytochromes b and c, and wild-type growth on high-iron media but low or no growth in low-iron broth and on solid media supplemented with the iron scavenger dipyridyl. Several iron(III)-solubilizing agents, such as citrate, hydroxyquinoline, and dihydroxybenzoate, stimulated growth of 116 on low-iron solid medium; anthranilic acid, the R. leguminosarum siderophore, inhibited low-iron growth of 116. The initial rate of 55Fe uptake by suspensions of iron-starved 116 cells was 10-fold less than that of iron-starved wild-type cells. Electron microscopic observations revealed no morphological abnormalities in the small, white nodules induced by 116. Nodule cortical cells were filled with vesicles containing apparently normal bacteroids. No premature degeneration of bacteroids or of plant cell organelles was evident. We mapped pop-1 by R plasmid-mediated conjugation and recombination to the ade-27-rib-2 region of the R. leguminosarum chromosome. No segregation of pop-1 and the symbiotic defect was observed among the recombinants from these crosses. Cosmid pKN1, a pLAFR1 derivative containing a 24-kilobase-pair fragment of R. leguminosarum DNA, conferred on 116 the ability to grow on dipyridyl medium and to fix nitrogen symbiotically. These results indicate that the insert cloned in pKN1 encodes an element of the iron acquisition system of R. leguminosarum that is essential for symbiotic nitrogen fixation.