The effects of denatured major bovine whey proteins on the digestive tract, assessed by Caco-2 cell differentiation and on viability of suckling mice.

Alpha-lactalbumin (α-LA) and ß-lactoglobulin (ß-LG) are contained in bovine milk whey. Chemical and physical treatments are known to alter the conformation of these proteins and we have previously reported that α-LA denatured with trifluoroethanol (TFE) and isolated from sterilized market milk inhibited the growth of rat crypt IEC-6 cells. In the present study, we aimed to evaluate the effects of TFE-treated α-LA and ß-LG on cell growth using cultured intestinal cells and on their safety using a suckling mouse model. First, we investigated the effect of the TFE-treated whey proteins on human colonic Caco-2 cells at various differentiation stages. In the undifferentiated stage, we assessed cell growth by a water-soluble tetrazolium-1 method. The native whey proteins enhanced cell proliferation, whereas the TFE-treated whey proteins strongly inhibited cell growth. We investigated cell barrier function in the post-differentiated stage by measuring transepithelial electrical resistance (TER). Not only native but also the TFE-treated whey proteins increased TER. Next, we evaluated whether the TFE-treated α-LA and ß-LG have adverse effects on healthy suckling mice. No mice given by the TFE-treated samples showed any adverse symptoms. We also performed a safety test using a human rotavirus infected gastrointestinal disease suckling mice model. Even the TFE-treated whey proteins appeared to prevent the development of diarrheal symptoms without any adverse effects. Although we cannot know the effect of long-term ingestion of denatured whey proteins, these results suggest that they have no adverse effects on differentiated intestinal cells and digestive tract, at least in short-term ingestion.

Differential Regulation of Thermodynamic Binding Forces of Levocetirizine and (S)-Cetirizine by Lys191 in Human Histamine H1 Receptors.

Cetirizine is a zwitterionic second-generation antihistamine containing R- and S-enantiomers, levocetirizine, and (S)-cetirizine. Levocetirizine is known to have a higher affinity for the histamine H1 receptors than (S)-cetirizine; ligand-receptor docking simulations have suggested the importance of the formation of a salt bridge (electrostatic interaction) between the carboxylic group of levocetirizine and the Lys191 residue at the fifth transmembrane domain of human histamine H1 receptors. In this study, we evaluated the roles of Lys191 in the regulation of the thermodynamic binding forces of levocetirizine in comparison with (S)-cetirizine. The binding enthalpy and entropy of these compounds were estimated from the van 't Hoff equation, by using the dissociation constants obtained from their displacement curves against the binding of [³H]mepyramine to the membrane preparations of Chinese hamster ovary cells expressing wild-type human H1 receptors and their Lys191 mutants to alanine at various temperatures. We found that the higher binding affinity of wild-type H1 receptors for levocetirizine than (S)-cetirizine was achieved by stronger forces of entropy-dependent hydrophobic binding of levocetirizine. The mutation of Lys191 to alanine reduced the affinities for levocetirizine and (S)-cetirizine, through a reduction in the entropy-dependent hydrophobic binding forces of levocetirizine and the enthalpy-dependent electrostatic binding forces of (S)-cetirizine. These results suggested that Lys191 differentially regulates the binding enthalpy and entropy of these enantiomers, and that Lys191 negatively regulates the enthalpy-dependent electrostatic binding forces of levocetirizine, contrary to the predictions derived from the ligand-receptor docking simulations.

A comparison between two negative pressure irrigation techniques in simulated immature tooth: an ex vivo study.

OBJECTIVES: This ex vivo study evaluated the irrigation efficacy of a new apical negative pressure system (ANP) in canals with simulated immature teeth, by comparing it to EndoVac (EV) system in terms of smear layer (SL) removal and irrigation extrusion. MATERIALS AND METHODS: Three millimetres of the root end of 40 single canalled lower incisors were resected and decoronated to standardize root canal length. After instrumentation, the specimens were embedded in warm normal saline agar coloured with 1 % acid red and randomly divided into four groups; one control group and three experimental groups. Except in the control group where distilled water was used as irrigant using positive pressure irrigation needle, the canals were irrigated with 6 % NaOCl and 17 % EDTA using the intracanal negative pressure needle (iNP) system, the EV system or 27G open-ended needle under positive pressure (PP). NaOCl extrusion was determined by observing a discolouration of the agar surrounding the root. The SL was evaluated by observing scanning electron microscope images based on a four-level scoring system. RESULTS: Two specimens with irrigant extrusion were observed in the iNP group, which was significantly different (logistic regression, p < 0.05) to EV and PP. There were no significant differences (Kruskall-Wallis test, p > 0.05) among the experimental groups in terms of SL removal, but all were significantly different to the control group. CONCLUSIONS: Irrigation with the iNP could be a viable alternative to EV as an apical negative pressure irrigation technique especially while treating immature teeth. CLINICAL RELEVANCE: ANP in canal cleanliness is recommended to be utilized in treating immature teeth where periapical tissues should be saved and stimulated. The iNP system might have the potential to avoid irrigant extrusion while cleaning the canal till the apical end.

A comparison of head-out mist bathing, with or without facial fanning, with head-out half-body low-water level bathing in humans--a pilot study.

To reduce the risks of Japanese-style bathing, half-body bathing (HBLB) has been recommended in Japan, but discomfort due to the cold environment in winter prevents its widespread adoption. The development of the mist sauna, which causes a gradual core temperature rise with sufficient thermal comfort, has reduced the demerits of HBLB. We examined head-out 42 °C mist bathing with 38 °C HBLB up to the navel to see if it could improve thermal comfort without detracting from the merits of HBLB, with and without the effects of facial fanning (FF). The subjects were seven healthy males aged 22-25 years. The following bathing styles were provided: (1) HBLB-head-out half-body low bathing of 38 °C up to the navel (20 min); (2) HOMB-head-out mist bathing of 42 °C and HBLB of 38 °C (20 min); and (3) HOMBFF-HOMB with FF (20 min). HOMB raised the core temperature gradually. HOMBFF suppressed the core temperature rise in a similar fashion to HOMB. Increases in blood pressure and heart rate usually observed in Japanese traditional-style bathing were less marked in HOMBs with no significant difference with and without FF. The greatest body weight loss was observed after Japanese traditional-style bathing, with only one-third of this amount lost after mist bathing, and one-sixth after HBLB. HOMB increased thermal sensation, and FF also enhanced post-bathing invigoration. We conclude that HOMB reduces the risks of Japanese traditional style bathing by mitigating marked changes in the core temperature and hemodynamics, and FF provides thermal comfort and invigoration.

Roles of Lys191 and Lys179 in regulating thermodynamic binding forces of ligands to determine their binding affinity for human histamine H1 receptors.

Docking simulations based on the crystal structure of human histamine H1 receptors have predicted crucial roles of Lys1915.39 and Lys179ECL2, which exist at the entrance of the ligand-binding pocket, in increasing the H1-receptor selectivity for carboxylated second-generation antihistamines via electrostatic interaction. In this study, we evaluated the roles of Lys1915.39 and Lys179ECL2 in regulating the thermodynamic binding forces of non-carboxylated and carboxylated antihistamines that determine their binding affinity for human H1 receptors. The binding enthalpy and entropy of the 3 sets of non-carboxylated and corresponding carboxylated antihistamines (doxepin and olopatadine, desloratadine and loratadine, and terfenadine and fexofenadine, respectively) were estimated using the van't Hoff equation with the dissociation constants obtained from the displacement curves of the non-carboxylated and carboxylated antihistamines against the binding of [3H]mepyramine to the membrane preparations of Chinese hamster ovary cells expressing human H1 receptors at various temperatures, ranging from 4 °C to 37 °C. We found that the affinity for carboxylated antihistamines was lower than that for the corresponding non-carboxylated compounds due to lower enthalpy-dependent electrostatic binding forces and/or entropy-dependent hydrophobic binding forces. Mutations of Lys1915.39 and/or Lys179ECL2 to alanine mostly increased the binding affinity for antihistamines due to a variety of changes in both enthalpy- and entropy-dependent binding forces. These results suggest that Lys1915.39 and Lys179ECL2 may not contribute to selectively increasing the binding affinity for carboxylated antihistamines via electrostatic interaction, but that they can negatively modulate the binding affinity for non-carboxylated and carboxylated antihistamines non-selectively by affecting their electrostatic as well as hydrophobic binding forces.

In vitro measurement of platelet adhesion to intact endothelial cells under low shear conditions.

BACKGROUND: Prediction of thrombus formation at intact arterial walls under low shear flow conditions is clinically important particularly for better prognoses of embolisation in cerebral aneurysms. Although a new mathematical model for this purpose is necessary, little quantitative information has been known about platelet adhesion to intact endothelial cells. OBJECTIVE: The objective of this study is to measure the number of platelets adhering to intact endothelial cells with a focus upon the influence of the shear rate. METHODS: Endothelial cells disseminated in µ-slides were exposed to swine whole blood at different shear rates. Adenosine diphosphate (ADP) was used as an agonist. Adherent platelets were counted by means of scanning electron microscopy. RESULTS: At an ADP concentration of 1 µM, 20.8 ± 3.1 platelets per 900 µm2 were observed after 30-minute perfusion at a shear rate of 0.8 s-1 whereas only 3.0 ± 1.4 per 900 µm2 at 16.8 s-1. CONCLUSIONS: The number of adherent platelets is determined by a balance between the shear and the degree of stimulation by the agonist. At an ADP concentration of 1 µM, a limit to the shear rate at which platelets can adhere to intact endothelial cells is considered to be slightly higher than 16.8 s-1.

Evaluation of the efficiency of a new file removal system in comparison with two conventional systems.

A novel file-removal system (FRS) was designed to address weak points of conventional file-removal methods. The purpose of this study was to compare file-removal time and dentin removal rates among the FRS, the Masserann kit (Micro-Mega, Besancon, France), and an ultrasonic file-removal method. Ninety extracted mandibular incisors with separated nickel titanium files were divided into 3 groups of 30 teeth each. Groups 1, 2, and 3 had file-removal attempts made by using the Masserann kit, a CPR-7 titanium ultrasonic tip (Obtura-Spartan Corp., Fenton, MO), and the FRS, respectively. Each group had three operators removing the separated files. Pre-/postoperative digital radiographs were downloaded into image analyzing software that calculated the amount of dentin removed. The FRS needed less time and had less dentin loss than the others (p<0.05). There were statistical differences between the experienced operator and less experienced operators regarding the file-removal time and the dentin removal rates (p<0.05).

Spreading of root canal irrigants on root dentine.

The purpose of this study was to evaluate the spreading of root canal irrigants on human root dentine. The spreading of various solutions on dentine surfaces was measured after pre-treatment with various conditional solutions. Seven experimental groups were set based on the combination of conditioning solution-test solution: none-distilled water; none-6% sodium hypochlorite (NaOCl); none-14.3% ethylenediaminetetraacetic acid containing surfactant 0.084% cetrimide (Morhonine); NaOCl-NaOCl; NaOCl-Morhonine; Morhonine-Morhonine and Morhonine-NaOCl. After application of 0.1 mL of conditioning solution for 60 s, 0.5 microL of test solution was placed on dentine surfaces. Spreading of test solution was measured for 480 s to examine the size of the contact area ratio. Those at 300 s were compared among groups using Fisher's Protected Least Significant Difference (P < 0.05). It was concluded that the contact area ratio of Morhonine-NaOCl increased the most significantly among all the experimental groups.

Effect of Laser Energy and Tip Insertion Depth on the Pressure Generated Outside the Apical Foramen During Er:YAG Laser-Activated Root Canal Irrigation.

OBJECTIVE: The risk of extrusion of irritative irrigants into the extraradicular tissue should be minimized during root canal irrigation. This study aimed to examine the pressure generated outside the apex during Er:YAG laser-activated irrigation (LAI) in comparison with passive ultrasonic irrigation (PUI) and conventional syringe irrigation (SI). BACKGROUND DATA: LAI is reported to be efficient for root canal debridement, whereas the apical pressure generated during LAI has not been investigated in detail. METHODS: Plastic root canal models (apical diameter = 0.40 mm, taper = 6%, and length = 20 mm) were irrigated with water using either LAI with an Er:YAG laser (Erwin AdvEr; 30, 50, or 70 mJ, 10 pps), PUI, or SI. The tip insertion depth was set at 2, 5, or 10 mm from the apex. The pressure generated outside the apical foramen was measured with a pressure sensor connected to the apex of the model. RESULTS: When the tip was positioned at 2 mm and the power setting was changed, the mean maximum pressure values were LAI (30 mJ) = PUI < LAI (70 mJ) < SI (p < 0.05). When LAI was performed at 70 mJ and the tip was positioned at 5 or 10 mm, the pressure values were PUI < LAI = SI (p < 0.05). CONCLUSIONS: LAI generated similar or lower pressure outside the apical foramen compared with SI, irrespective of the laser energy and tip insertion depth examined. However, LAI generated higher pressure compared with PUI.

A Reactive Oxygen/Nitrogen Species Sensor Fabricated from an Electrode Modified with a Polymerized Iron Porphyrin and a Polymer Electrolyte Membrane.

We have developed an electrochemical reactive oxygen/nitrogen species sensor that can detect superoxide anion radicals (O2-•) and nitric oxide (NO). The reactive oxygen/nitrogen species sensor was fabricated by surface modification of an electrode with polymerized iron tetrakis(3-thienyl)porphyrin (FeT3ThP), and it can detect either O2-• or NO by switching the applied potential. Furthermore, we fabricated a sensor with improved selectivity by coating a Nafion® film onto the poly(FeT3ThP)-modified electrode. An interference current caused by NO2- was seen for the poly(FeT3ThP)-modified electrode, while the interference current was significantly reduced at the Nafion®/poly(FeT3ThP)-modified electrode, leading to improved selectivity for NO detection. The current response at the Nafion®/poly(FeT3ThP)-modified electrode exhibited good linearity in the O2-• and NO concentration ranges 1.3 - 4.1, and 0.5 - 10 µM, respectively. The Nafion®/poly(FeT3ThP)-modified and poly(FeT3ThP)-modified electrodes are highly versatile, because these electrodes can detect either O2-• or NO by switching the applied potential. Since the Nafion®/poly(FeT3ThP)-modified and poly(FeT3ThP)-modified electrodes contain no bio-derived compounds, the reactive oxygen/nitrogen species sensor should be safe even when it is used in vivo.

Soleal vein dilatation assessed by ultrasonography is an independent predictor for deep vein thrombosis after major orthopedic surgery.

BACKGROUND: Deep vein thrombosis (DVT) develops after major orthopedic surgery despite the current use of prophylaxis. DVT frequently develops in the soleal vein (SV) and might develop easily at the site of SV dilatation because of blood flow stasis. However, whether preoperative SV dilatation detected by ultrasonography predicts DVT after major orthopedic surgery remains unknown. OBJECTIVE: We examined whether SV dilatation detected by preoperative ultrasonography predicts DVT after major orthopedic surgery. METHODS: Ultrasonography was performed preoperatively and postoperatively in 243 patients with orthopedic diseases (mean age of 67±13 years, 77% women) who underwent total hip arthroplasty (THA, n=180) or total knee arthroplasty (TKA, n=63). Presence of DVT was diagnosed by ultrasonography and SV diameter ≥10mm was defined as SV dilatation. Patients with preoperative DVT were excluded. RESULTS: Sixty-nine patients (28%) developed postoperative DVT. SV dilatation was found in 24 patients (10%), and 16 (67%) of those patients had postoperative DVT. Multivariate logistic regression analysis showed that female gender [odds ratio (OR): 4.09, p=0.004], TKA (OR: 2.52, p=0.011), and SV dilatation (OR: 6.67, p<0.001), but not presence of comorbidities, medications, or plasma d-dimer value, independently predict postoperative DVT. Subgroup analyses according to the operation site showed that female gender (OR: 3.27, p=0.043) and SV dilatation (OR: 3.72, p=0.022) were independent predictors of postoperative DVT in the THA group. SV dilatation (OR: 12.0, p=0.027) was an independent predictor of postoperative DVT also in the TKA group. CONCLUSIONS: In addition to gender and TKA, SV dilatation detected by ultrasonography is an independent predictor of DVT after major orthopedic surgery. Determination of SV diameter by ultrasonography before major orthopedic surgery is useful for assessing the risk of postoperative DVT.

Quality of gutta-percha root canal fillings using differently tapered gutta-percha master points.

The aim of this study was to evaluate the quality and adaptability of gutta-percha root canal fillings to the root canal walls when two different tapered gutta-percha master points (GPMP) were used to fill a split-tooth model. A maxillary central incisor was prepared for the split-tooth model and 10 fillings for group A (ISO .02 GPMP) and group B (ISO .10 GPMP) were carried out. The System B and the Obtura II were used to fill the split-tooth model and replication of round artificial depressions, voids within the gutta-percha (GP) and spaces between the GP and the root canal walls were evaluated and scored. Individual scores of each parameter evaluated were compared between the two groups and statistically analyzed using the Mann-Whitney U test. Group A showed statistically significant better scores (p < 0.05) for the replication of the artificial round depressions and spaces between the GP and the root canal walls. No statistically significant differences were found between the two groups for internal voids. It is concluded that the location of the GPMP binding point and the greater mass of the .10-Tapered GPMP may affect the quality and adaptation of the root canal filling in the important apical part of the canal.

Detection rate of root canal orifices with a microscope.

The purpose of this study was to compare the detection rate of root canal orifices by three different methods: naked eye, with surgical loupes, and under a microscope. Two undergraduate dental students located the orifices of 260 teeth by using the above-mentioned methods. Then, India ink was injected into the pulp chamber and all teeth were cleared to determine the actual number of the orifices. There was a significant difference in the detection rate among the three methods (p < 0.01, chi-square test); the microscopic method could more accurately detect orifices than the others could. Surgical loupes were relatively ineffective compared with the microscopic method for detecting orifices.

Electronic detection of root canal constrictions.

The aim of this study was to investigate the possibility of detecting root canal constrictions by using an apex locator. Seventy impenetrable canals in extracted human teeth were used. Based on contact microradiographic findings, they were divided into three groups: group A (constricted within 3 mm of the radiographic apex, 23 canals), group B (nonconstricted within 3 mm of the radiographic apex, 28 canals), and group C (constricted more than 3-mm short of the radiographic apex, 19 canals). Electrical impedances at two different frequencies (8 kHz and 0.4 kHz), as well as the meter values of the Root ZX were recorded at the position where a file tip could reach. The impedance ratios (Z8kHZ:Z0.4kHz) and the meter values of the Root ZX showed a statistically significant difference between groups A and B. It was suggested that the Root ZX might be useful for detecting root canal constrictions.

An observation of the healing process of periapical lesions by digital subtraction radiography.

The purpose of this study was to evaluate the efficacy of digital subtraction radiography using a direct digital imaging system in the follow-up study of endodontically treated teeth. The RVG-S was used as a direct digital imaging system. The intraimage variation of the original RVG-S image caused by dark current and sensitivity variations among pixels was corrected by pixel-to-pixel. The interimage variation was further corrected using a copper step-wedge attached to the sensor. Standardized images were obtained from the same geometrical setup during the follow-up. Pixel values at the regions of interest positioned on the periapical lesion increased after the endodontic treatment, and this change continued during the observation period up to 545 days. The subtraction method with direct digital radiography will be a useful tool to evaluate the healing process in endodontic treatments.

Three-step versus single-step use of system B: evaluation of gutta-percha root canal fillings and their adaptation to the canal walls.

This study aimed to evaluate the quality of gutta-percha (GP) root canal fillings and their adaptation to the root canal walls, when the System B was used in three steps and a single step to fill three different split-tooth models. Each model was filled 10 times in two different ways. Group A: the System B plugger was used to fill the apical 3 mm of the canal in three steps, and then the Obtura II was used to backfill the rest of the canal. Group B: the System B plugger was inserted just once to a distance 3 mm short of the working length and then backfilled as in Group A. Replication of artificial depressions, presence of voids within the GP mass, and presence of spaces between the GP mass and the root canal walls were evaluated and scored. The individual scores of each parameter evaluated were compared between the two groups and statistically analyzed by use of the Mann-Whitney U test. Group A showed statistically significant (p < 0.05) better scores than Group B concerning the replication of artificial depressions and spaces between the GP mass and the canal walls. It was concluded that better adaptation of the GP mass to the canal walls in the apical third was obtained when the System B plugger was used in three steps.

Radiographic evaluation of root canal multiplicity in mandibular first premolars.

The purpose of this study was to examine the accuracy of radiographic evaluation of root canal multiplicity in mandibular first premolars in vitro. One hundred thirty-nine extracted human mandibular premolars were used. Buccolingual radiographs were taken, and the number of canals in each tooth was determined on radiographs by four dentists using a view box. A sudden narrowing of the main canal was interpreted as a sign of multiple canals. After the radiographic evaluation, the tooth crown was removed. India ink was injected into the root canal system, and the root was cleared to observe the canal morphology. There was no statistically significant difference among the four dentists with respect to the coincidence rate (93%-96%) of the canal number evaluated on radiographs with that identified by cleared teeth observation (p > 0.05, one-way analysis of variance). A sudden narrowing of the main canal on the radiograph was a good criterion to judge root canal multiplicity.

Obturation of accessory canals after four different final irrigation regimes.

The aim of this study was to evaluate accessory canal obturation after four different final irrigation regimes. Sixty-four extracted human lower premolars were instrumented, divided randomly into four groups, and finally irrigated as follows: no irrigation (NO), distilled water (WA), sodium hypochlorite ([SH] 6%, 20 ml for 15 min), and EDTA (15%, 8 ml for 3 min) combined with the SH regimen (ES). The System B and the Obtura II were used to fill the canals. The teeth were cleared and observed under a digital microscope. Obturation material penetration rates in length into the accessory canals were measured and the following values were obtained: 22.3% in group NO, 21.8% in group WA, 53.5% and 68.1% in groups SH and ES, respectively. Statistically significant differences were found when comparing each of the first two groups (NO and WA) with SH and ES groups (p < 0.05). The use of sodium hypochlorite alone or in combination with EDTA in final irrigation flushes may enhance a better obturation material penetration into the accessory canals.

The influence of orifice sealing with various filling materials on coronal leakage.

The aim of this study was to evaluate the sealing ability of materials filled in the orifice after root canal treatment. A total of 100 root canal-treated teeth were divided into six experimental groups: 1, Protect Liner F (PL); 2, Panavia F (PF); 3, DC core-Light cured (DCL); 4, DC core-Chemically cured (DCC); 5, Super-EBA (SE); 6, Ketac (KC). The materials were filled--to a depth of 4 mm--in the coronal part of the root canals, and evaluated for microleakage. The number of teeth that failed to stop dye penetration in the filled materials differed statistically between PL and DCL or SE or KC, PF and SE or KC, DCC and KC, DCL and KC. The mean distance of dye penetration differed significantly between PL and SE or DCC, PF and SE or DCC. Hence, these results indicated the advantageous sealing ability of adhesive and flowable materials.