Relationship between age-related changes in mandibular third molar roots and the possibility of mental nerve paresthesia after tooth extraction.

Mental nerve paresthesia is a serious postoperative complication of mandibular third molar extraction. It appears that no study has examined the relationship between the surface morphology of the mandibular third molar roots and the possibility of mental nerve paresthesia following tooth extraction. Therefore, the root morphology of the mandibular third molars was examined according to age using dental cone beam computed tomography (CBCT), and the possibility of mental nerve paresthesia following tooth extraction was evaluated. The study included 1216 patients who had undergone mandibular third molar extractions. The root morphology of 1534 teeth in 791 patients who had CBCT performed before surgery was studied. Factors evaluated were age, complete or incomplete formation of the mandibular third molar roots, periodontal ligament atrophy of the mandibular third molar roots, hypercementosis, and mandibular canal deformation. Mandibular third molar root formation was completed between the ages of 19 and 30 years. Complete formation of the mandibular third molar roots (P = 0.002) and deformation of the mandibular canal (P < 0.001) were identified as risk factors for mental nerve paresthesia. These findings suggest that the risk of mental nerve paresthesia could be reduced if the extraction of third molars is performed prior to complete root formation.

Isolation and purification of a protective protein antigen of Erysipelothrix rhusiopathiae.

The rapid growth and high survival rate of Erysipelothrix rhusiopathiae was determined using a culture of the bacterium in tryptic soy broth supplemented with 0.3% Tris-hydroxymethyl aminomethane and 0.1% Tween 80 (TT-TS broth). High concentrations of 64, 66 and 43 kDa proteins, which are associated with protection against E. rhusiopathiae infection in mice, were obtained by alkaline treatment of whole cells using 0.05-1 N NaOH. The supernatant of alkaline treated cells (alkaline extract; AE) was stable at alkaline or neutral pH. However, aggregates appeared at neutral pH in the absence of sodium dodecyl sulphate (SDS). A high yield of 64, 66 and 43 kDa proteins was obtained from strain Agata (serovar 5). The proteins were eluted from gel bands following SDS-polyacrylamide gel electrophoresis (SDS-PAGE) of the AE from strain Agata and designated P64 and P43. The amounts of P64 and P43 isolated were 0.7 and 0.3 mg/16 g of wet bacteria, respectively. In a mouse protection test, 50% protective doses (PD50) of P64 and P43 were 0.58 and 0.63 microgram, respectively. Upon Western blotting of the AE, both anti-P64 and anti-P43 antibodies reacted with the 64 and 43 kDa proteins. From these results, it is suggested that P64 is the most effective protective antigen and that P43 (43 kDa protein) is a degradation product of P64. Therefore, the 64 kDa structural proteins are associated with the induction of a protective activity against E. rhusiopathiae infection in mice.

Protective activity of the purified protein antigen of Erysipelothrix rhusiopathiae in pigs.

We purified the protein antigen (P64), which contains 66 and 64 kDa proteins, from the alkaline extract (AE) of whole cells of Erysipelothrix rhusiopathiae strain Agata (serovar 5) to determine the protective activity of the antigen against E. rhusiopathiae infection in pigs. The serum titre of antibody against P64 rapidly increased in pigs immunized with 500 and 100 micrograms of P64 and reached maximum values at 3 weeks after the first immunization (1 week after the second immunization). However, the serum antibody titres were not increased in pigs immunized with 20 micrograms of P64 and in nonimmunized pigs. In the pigs immunized with live cell vaccine (acriflavin-fast attenuated strain Koganei 65-0.15), the serum titres of antibody against P64 also increased at 1-2 weeks after immunization. In a pig challenge test performed on immunized and nonimmunized pigs, all nonimmunized pigs showed typical clinical signs of swine erysipelas (fever, erysipeloid, arthritis), while all pigs immunized with 500 and 100 micrograms of P64 and live cell vaccine showed no clinical signs of this disease. In Western blot analysis, sera from pigs immunized with P64 and live cell vaccine strongly reacted with the 64 kDa protein. In contrast, the serum from nonimmunized pigs did not react with any proteins. From these results, it was suggested that a specific antibody against the 64 kDa protein could be increased in pigs immunized with P64 or live cell vaccine and that this anti-P64 antibody has a strong protective effect against E. rhusiopathiae infection in pigs.

Simultaneous determination of bile acids in rat liver tissue by high-performance liquid chromatography.

A method for the simultaneous determination of bile acids in rat liver tissue by high-performance liquid chromatography was developed. Without prior fractionation and alkaline hydrolysis, 30 unconjugated, glycine- and taurine-conjugated bile acids were detected by post-column enzymatic reaction and fluorescence detection. They were separated on a reversed-phase column using a linear gradient solvent system of 10 mM tribasic ammonium phosphate-acetonitrile-methanol (44:12:5, v/v/v) and 20 mM dibasic ammonium phosphate-acetonitrile-methanol (2:1:2, v/v/v). The limits of detection were 1-5 pmol, and calibration curves were linear for concentrations ranging between 10 and 4000 pmol per 10 microl injection. This rapid and reliable method is effective for measuring bile acid levels in liver tissue not only of rats but also of patients with hepatobiliary and other diseases.

Basic studies on N''-ursodeoxycholyldiethylenetriamine-N,N,N'-triacetic acid for the dissolution of calcified gallstones.

A novel calcium-chelating agent, N"-ursodeoxycholyldiethylenetriamine-N,N,N'-triacetic acid (UDCA-DTTA), was synthesized to study its ability to dissolve calcified gallstones. The chelating activity of the compound was demonstrated by dissolving calcium carbonate in vitro at a high dissolution rate. In the presence of the agent, sliced human gallstone with a composition of more than 50% calcium bilirubinate was thoroughly dissolved, indicating that calcium bilirubinate was dissolved from the gallstone. The ability to dissolve calcium was comparable to that of EDTA. However, the laminar structure of the sliced gallstone did not disappear in the presence of EDTA, whereas the structure disappeared in the presence of UDCA-DTTA. All these results indicate that UDCA-DTTA is an interesting compound as a parent substance for developing a prodrug for an oral or intravenous agent to dissolve calcium-containing gallstones.

The choleretic effects of N-acetylglucosaminides, major urinary metabolites of ursodeoxycholic acid, in bile fistula rats.

We investigated the effects of three bile acids conjugated with N-acetylglucosamine, ursodeoxycholate N-acetylglucosaminide, tauroursodeoxycholate N-acetylglucosaminide and glycoursodeoxycholate N-acetylglucosaminide, on bile flow and biliary excretion of various markers in comparison with ursodeoxycholic acid, tauroursodeoxycholic acid and glycoursodeoxycholic acid in bile fistula rats. These bile acids were infused intravenously at a constant rate of 0.3 or 0.6 micromol/min/100 g b.w. for 2 h. All bile acids examined increased bile flow in a dose-dependent manner. In particular, ursodeoxycholate N-acetylglucosaminide has a longer-lasting effect after its infusion on bile flow than the other bile acids. Furthermore, these bile acids markedly increased biliary total bile acid excretion. At a higher dose level, the coefficient of determination (r2) between the biliary total bile acid excretion and bile flow for ursodeoxycholate N-acetylglucosaminide (r2 = 0.39) was lower than that for the other bile acids (r2 = 0.75-0.92). The ursodeoxycholate N-acetylglucosaminide, as well as tauroursodeoxycholic acid, glycoursodeoxycholic acid, tauroursodeoxycholate N-acetylglucosaminide and glycoursodeoxycholate N-acetylglucosaminide, was mostly excreted in an unchanged form in bile, whereas ursodeoxycholic acid was excreted as a conjugate with taurine. The three N-acetylglucosaminides as well as ursodeoxycholic acid, tauroursodeoxycholic acid and glycoursodeoxycholic acid significantly increased the biliary excretion of cholesterol, phospholipid, bilirubin and total Ca2+. In contrast, the N-acetylglucosaminides significantly decreased in biliary bicarbonate concentration, whereas ursodeoxycholic acid significantly increased biliary bicarbonate concentration. However, tauroursodeoxycholic acid and glycoursodeoxycholic acid did not significantly change the biliary bicarbonate concentration. The results indicate that N-acetylglucosaminides have a choleretic effect in bile fistula rats. Our present study also demonstrates that N-acetylglucosaminides, but not ursodeoxycholic acid, tauroursodeoxycholic acid or glycoursodeoxycholic acid, can significantly reduce the biliary bicarbonate concentration. Furthermore, our findings suggest that ursodeoxycholate N-acetylglucosaminide may partly exert a choleretic effect via mechanisms different from those of the other bile acids.

Improvement of estradiol-17 beta-D-glucuronide-induced cholestasis by sodium tauroursodeoxycholate therapy in rats.

BACKGROUND: Estradiol-17 beta-D-glucuronide (E-17G), a metabolite of natural estrogen, is well known to cause intrahepatic cholestasis in humans. We therefore investigated the effect of sodium tauroursodeoxycholate (T-UDCA), on E-17G-induced cholestasis in female rats. METHODS: For the evaluation of the drug, animals given E-17G (10 mumol/kg) were divided into three groups, and T-UDCA was administered intravenously at various doses after E-17G treatment. RESULTS: T-UDCA significantly prevented a marked reduction of bile flow in E-17G-treated rats in all experimental schedules. Furthermore, T-UDCA significantly increased in the biliary E-17G excretion rate at an early stage after E-17G treatment in rats. However, this drug caused no significant change in the biliary excretion rate of estradiol-3-sulfate-17 beta-D-glucuronide (E-3S-17G), which is identified as the major biliary metabolite with E-17G throughout the recovery periods. CONCLUSION: These results suggest that T-UDCA can improve E-17G induced acute cholestasis by rapidly increasing the biliary E-17G excretion rate. Thus our finding may provide a useful approach for attempts to prevent drug-induced acute cholestasis in humans.

Simultaneous determination of bile acids in rat bile and serum by high-performance liquid chromatography.

A method for the simultaneous determination of bile acids in rat bile and serum by high-performance liquid chromatography with a post-column enzymic reaction and fluorescence detection has been developed. Without prior fractionation and alkaline hydrolysis, 26 unconjugated, glycine- and taurine-conjugated bile acids were determined. They were separated on a reversed-phase column using a linear gradient solvent system of 200 mM dibasic ammonium phosphate buffer (pH 7.9)-acetonitrile-methanol (73:19:8, v/v/v) and 20 mM dibasic ammonium phosphate buffer (pH 7.9)-acetonitrile-methanol (2:1:2, v/v/v). The limits of detection were 1-5 pmol, and calibration curves were linear for concentrations between 10 and 4000 pmol. This rapid and reliable method is effective for measuring bile acid levels in the bile and serum not only of rats but also of patients with hepatobiliary and other diseases.

[Morphological changes of osteogenic cells on hydroxyapatite ceramics sintered at different temperatures].

In order to clarify the relation between the synthetic condition and the biocompatibility in vitro, a dynamics of the osteogenic MC3T3-E1 cells cultured on hydroxyapatite ceramics (HAC) was examined. HAC used in this study was sintered at temperatures of 1000 degrees C or 1350 degrees C to produce the dense ceramics material, and then smoothly surfaced (0.3 micron). Disk (diameter: 10mm, thickness: 1mm) of HAC were placed in plastic disk. The cells were inoculated at 3000 cells/disk on HAC, and cultured for up to 18 Days. In scanning electron microscopic observation, cell proliferation cultured on the polished HAC was more active than that on the unpolished HAC. Furthermore, cell proliferation cultured on the 1000 degrees C-HAC was more active than that on the 1350 degrees C-HAC. Width, length and concentration of microvilli (MV) on the cell surface cultured on the 1000 degrees C-HAC were more dense, and increased with cultivation. Length and concentration of MV of the cells cultured on the 1000 degrees C-HAC were more dense than that on the 1350 degrees C-HAC. Most of the cells cultured on each material were intensely positive with alkaline phosphatase or von Kossa staining. However, the cells cultured on the 1000 degrees C-HAC were more positive than those on 1350 degrees C-HAC. In conclusion, these results suggest that the synthetic condition of HAC have close connection with the biocompatibility.

Influence of saccadic eye movements on geniculostriate excitability in normal monkeys.

Using permanently implanted electrodes in squirrel monkeys and macaques, transmission through the lateral geniculate nucleus (LGN) was assayed from the amplitude of potentials evoked in optic radiation by and electrical pulse applied to optic tract. Averaging of either individually or machine selected potentials, elicited at 0.3, 1.0, 20 or 50 HZ, in all cases showed a decrease in transmission ranging from 5-60% in the period after saccadic eye movements made ad libitum. The suppression was greater in a patterned visual environment than in diffuse illumination, which in turn was greater than that occurring following saccades in the dark. Demonstration of the effect in darkness always required data averaging and never exceeded 20%. The effect was consistently greater in the magnocellular than parvocellular component. Suppresion was often abruptly terminated and replaced by a facilitation of 5-15% about 100 msec after saccade detection. Comparable effects were observed for excitability of striate cortex tested by a stimulus pulse applied to optic radiation. In addition, sharply demarcated potentials inherently arising in LGN and striate cortex were found in association with saccades made even in total darkness. Neglecting a possible but dubious contribution from eye muscle proprioceptors, the experiments establish the existence of a centrally originating modulation of visual processing at both LGN and striate cortex in ralation to saccadic eye movement in primates. This modulation may partially underlie the phenomenon of "saccadic suppression" and hasten the acquistion of a meaningful visualsample immediately following an ocular saccade. It remains uncertain as to how it may relate to similar or greater effects accompanying changes in alertness, or to fluctuations of unknown origin occurring sometimes semirhythmically at 0.05-0.03 HZ (Fig 7).

EEG of striate cortex in blind monkeys: effects of eye movements and sleep.

After control studies, using electrodes permanently implanted in the central visual system, squirrel monkeys and macaques were in most instances blinded by acute glaucoma. This permitted subsequent observation of eye movements. Ocular nystagmus developed in all cases. Beginning immediately upon recovery from anesthesia, and persisting for at least 1 year, the EEG of the striate cortex was characterized by totally flat periods up to several seconds in duration which were ended abruptly by a sharp "spike" trailed in turn by a ragged high voltage, slow pattern for another second or two. The great majority of these "spikes" from the blind striate cortex occurred within 60-200 msec after a saccadic eye movement, made either in nystagmus or attempted fixation. They were not dependent upon proprioception from the extraocular muscles. It is suggested that they represent a "corollary discharge" for movement of the eyes. The blind striate cortex was judged to be hyperexcitable on the basis of these saccade-associated "spikes", not often observable in intact monkeys, and from the increase both in response evoked by electrical stimulation of optic radiation and amplitude of the EEG in sleep.