Effects of hydrocortisone and beta-aminopropionitrile on stress-strain and stress-relaxation behaviors, and birefringent retardation of collagen fibers in the rat incisor periodontal ligament

Three groups of male Wistar rats received daily subcutaneous injections of 10 mg/kg of hydrocortisone (HC group), 300 mg/kg of beta-aminopropionitrile (BAPN group), or saline (control group), for 10 days. The shear stress-strain and stress-relaxation properties of the incisor periodontal ligament were examined in transverse sections from dissected mandibles. Both the maximum shear stress and failure strain energy density increased significantly following the administration of hydrocortisone. The maximum shear stress decreased following the administration of BAPN. However, the stress-relaxations in the initial 10 min did not show significant differences among the three groups. Polarized light microscopic analysis revealed that the retardation value of the collagen fibers was highest in the HC group and lowest in the BAPN group for the bone-related area, but not for the tooth-related and middle areas of the ligament. It is suggested that the changes induced by hydrocortisone or BAPN occurred mainly in the elastic components and to a minor extent in the viscous components although the physical and biomechanical properties are determined by the interaction of all the various components. We also suggest that the main response to the drugs occurred in the collagen fibers in the bone-related area of the ligament.

[Utility of the perfusion-assist for beating heart coronary artery bypass surgery]

During off-pump coronary artery bypass surgery, concern remains about the possible myocardial injury associated with the transient occlusion and stabilization of the target vessels. To try to minimize myocardial ischemia and achieve hemodynamic stability, we utilized a coronary perfusion catheter combined with the perfusion-assisted direct coronary artery bypass system that enables active and modified coronary perfusion of the target vessel throughout the duration of multiple grafting (modified PADCAB). In the series of 10 patients, perfusion of the target coronary systems averaged 2,072.8 +/- 649.7 ml over 92.9 +/- 26.1 minutes under a constant infusion pressure of 120 mmHg. Nitroglycerin (100 micrograms/l of flow) was delivered directly into the coronary arteries as an additive in all patients. Hemodynamic instability was notably absent in all cases, even in cases that required difficult anastomosis with a relatively long time for the anastomosis. There were no perioperative complications and no detectable myocardial damage (i.e., impairment of myocardial wall motion indicated by echocardiography findings or by > 0.25 ng/ml of troponin-T release compared to the preoperative level) in this series of patients.

The effects of intrusive loading on axial movements of impeded and unimpeded rat incisors: estimation of eruptive force

Axial movements of impeded and unimpeded rat mandibular incisors were measured following application and removal of intrusive loads of 1, 2, 5, 10 and 20 mN in a stepwise order at intervals of 1h on erupting teeth. The tooth movements were recorded by a displacement detector under artificial respiration with halothane anaesthesia. The loading and unloading procedures brought about the tooth movements in two steps: an initial rapid movement immediately after application or removal of the load and a subsequent slow and gradual movement. The initial rapid intrusive or extrusive tooth movements were significantly greater in the unimpeded than in the impeded teeth at the same load. The forces to stop extrusive tooth movements, estimated from the formula of regression lines showing correlations between the intrusive loads from 0 to 5 mN and tooth movements (microm/30 min), were 4.2 mN in the impeded and 2.9 mN in the unimpeded incisors. We suggest that repeated shortenings of the rat incisor did not cause an increase in the eruptive force and that changes in the resistance of the periodontal ligament predominantly regulate the axial movement of the rat incisor.

Detection of cerebral hypoperfusion with bispectral index during paediatric cardiac surgery

BACKGROUND

The bispectral index (BIS) may indicate changes in cerebral activity when the cerebral circulation is affected by acute hypotension.

METHODS

We measured BIS and cerebral haemoglobin saturation (Sr(O(2))) by near-infrared spectroscopy in 10 children undergoing cardiac surgery.

RESULTS

We noted 14 episodes of simultaneous decreases in Sr(O(2)) and BIS during acute hypotension in five children. An acute decrease in BIS, which coincided with a decrease in Sr(O(2)) suggesting a reduction in cerebral blood flow, was associated with acute slowing of the raw EEG waveforms.

CONCLUSIONS

Our findings suggest that an acute decrease in BIS during acute hypotension indicates cerebral hypoperfusion, and that cerebral hypoperfusion caused by hypotension may occur frequently during paediatric cardiac surgery.

Electromyographic activity of the jaw-closing muscles during jaw opening--comparison of cases of masseter muscle contracture and TMJ closed lock

Contracture of jaw-closing muscles is one of the causes of limitations of jaw opening. In contracture patients who have no history of trauma or infection, it is not easy to distinguish contracture from temporomandibular joint (TMJ) closed lock (TCL). The purpose of this study was to clarify whether there is any difference between electromyographic (EMG) activities of jaw muscles during jaw opening in patients with TCL and patients with masseter muscle contracture (MMC). The MMC-patient group consisted of one male and 11 females with no history of trauma or infection. The TCL-patient group consisted of one male and 11 females. Ten of the MMC patients showed certain types of EMG activities in masseter muscles (and eight in temporal muscles) during jaw opening. However, particular EMG activities were not observed in most of the TCL patients. The integral values in masseter muscles and in temporal muscles at the maximum opening position were significantly higher in the MMC-patient group than those in the TCL-patient group. These findings demonstrate that the EMG pattern of MMC patients without a history of trauma or infection is different from that of TCL patients. Therefore, EMG analysis of jaw-closing muscles during jaw opening is expected to be useful for differential diagnosis between MMC and TCL.

[Specific features of p53 protein induction after ionizing radiation in cells of patients with Nijmegen breakage syndrome]

Synthesis of p53 and WAF1 (p21) proteins was studied in cells of patients with Nijmegen breakage syndrome (NBS) and of patients with ataxia telangiectasia (AT), as well as in normal cells with respect to their response to ionizing radiation (IR). In the NBS cells, the p53 protein was progressively accumulated with increasing radiation dose and reached the maximum 2 h after exposure to radiation at a dose of 5 Gy. The amount of p53 protein was consistently lower than that in normal cells, which was correlated with low content of the WAF1, the protein regulated by p53 at the level of transcription. Suboptimal induction of p53 observed in NBS cells was also characteristic of the AT cells, though the quantitative parameters of the protein synthesis in AT cells were intermediate relative to those in normal and NBS cells. In four NBS lines, the time schedule of p53 synthesis was similar to that observed in normal cells, whereas in AT cells, induction of p53 was significantly delayed as compared to control. In response to irradiation, the amount of p53 protein synthesized in patients with AT and NBS was significantly lower than that in normal cells. The results obtained, as well as the previously published medical and genetic evidence, suggest that the two diseases are of different origin and different genes are responsible for their development.

A 13C NMR study on the adsorption characteristics of HEMA to dentinal collagen

To develop a more effective primer, we must understand how 2-hydroxyethylmethacrylate, the HEMA primer, enhances bonding at the resin-dentin interface. In this study, to obtain an insight into the adhesion mechanisms of adhesive resin to etched dentin through HEMA, we examined the adsorption characteristics of HEMA to dentinal collagen by using the 13C NMR technique. The addition of dentinal collagen to the HEMA solution resulted in a decrease in T(1) values of carbons attributed to the HEMA, thus reflecting an interaction between HEMA and collagen. Specifically, a reduction in the T(1) value in the ester carbonyl carbon attributed to HEMA greater than that in the other carbons suggested the formation of a hydrogen bond between the ester carbonyl group in HEMA and the dentinal collagen.

[matK and its nucleotide sequencing of crude drug chuanxiong and phylogenetic relationship between their species from China and Japan]

AIM

To provide more molecular evidences for species relationship between Chuanxiong (Ligusticum chuanxiong Hort.) from China and Japanese Chuanxiong (Senkyu in Japanese) (Cnidium officinale Makino).

METHODS

To sequence such two genes as internal transcribed spacer (ITS) from nuclear rDNA and maturase for lysine (matK) in tRNA(lys) (UUU) intron from chloroplast DNA of both Ligusticum chuanxiong and Cnidium officinale using PCR direct sequencing and to analyze the sequence variation of two genes between these two species.

RESULTS

The matK gene sequence of Ligusticum chuanxiong and Cnidium officinale is 1268 bp in length, coding 422 amino acids of maturase protein. ITS gene sequence 699 bp, consisting of 54 bp of 18S rRNA-3', 215 bp of ITS1, 162 bp of 5.8S rRNA, 222 bp of ITS2, 46 bp of 26S rRNA-5'. Multiple sequence alignment shows that the sequence of two genes between dried crude drug and fresh voucher material of Ligusticum chuanxiong and Cnidium officinale, there is 1 variable site (T-->C) in matK (upstream at 595 nt) and ITS (ITS1 at 54 nt) between Ligusticum chuanxiong and Cnidium officinale.

CONCLUSION

Based on homology analysis of two genes plastid matK and nuclear ITS, the origin of Chuanxiong from China and Japan ought to be identical, the scientific name Cnidium officinale of Japanese Chuanxiong should be changed to Ligusticum chuanxiong.

Molecular analysis of medicinally-used Chinese and Japanese Curcuma based on 18S rRNA gene and trnK gene sequences

Curcuma drugs have been used discriminatingly for invigorating blood circulation, promoting digestion, and as a cholagogic in China. However, there is confusion about the drug's botanical origins and clinical uses because of morphological similarity of Curcuma plants and drugs. In order to develop an ultimate identification, molecular analysis based on 18S rRNA gene and trnK gene sequences were performed on 6 Curcuma species used medicinally in China and Japan. The 18S rRNA gene sequences were found to be of 1810 bps in length. In comparison with the common sequence of C. longa, C. phaeocaulis, C. wenyujin and C. aromatica, that of C. kwangsiensis had one base substitution, and the same base difference was observed between the Chinese and the Japanese populations of C. zedoaria. The trnK gene sequences were found to span 2698-2705 bps. There were base substitutions, small deletions or insertions at some sites between the trnK coding region and matK region among each species. Based on the base substitutions, C. zedoaria and C. kwangsiensis specimens were divided into two groups, respectively. An identical sequence was detected in C. phaeocaulis and in the Chinese population of C. zedoaria, as well as in the Japanese population of C. zedoaria and in one group of C. kwangsiensis with a purple-colored band in leaves. New taxonomic information to be used for authenticating Curcuma drugs was obtained.

Protective effect of Salvia miltiorrhiza on angiotensin II-induced hypertrophic responses in neonatal rat cardiac cells

The effect of the root of Salvia miltiorrhiza (SM) on angiotensin II (Ang II)-induced hypertrophic responses was examined in cultured neonatal rat cardiac cells (cardiomyocytes and non-cardiomyocytes). The methanol eluate fraction (SM2) of the water extract and the ethyl acetate-insoluble fraction (SM3) and its soluble fraction (SM4) partitioned from the methanol extract were prepared. Treatment with SM4 (5-80 microg/ml), not SM2 and SM3, for 24 h produced dose-dependent cytotoxicity against cardiac cells relative to the reduction in viability and the morphological injury of cardiomyocytes. SM2 or SM3 in the absence of Ang II affected neither hyperplastic nor hypertrophic growth of both cell types. However, SM3 (40 microg/ml) attenuated the positive chronotropic responsiveness of cardiomyocytes to Ang II (1 nM) stimulation, whereas Ang II-induced increase in non-cardiomyocyte number was decreased only by SM2 (40 microg/ml) treatment. Furthermore, SM3 suppressed Ang II-induced enlargement of cell size by preceding Ang II-induced induction of immediate early response gene (c-jun) expression in cardiomyocytes, while SM2 decreased Ang II-induced DNA synthesis in non-cardiomyocytes. Moreover, three phenolic compounds and tanshinone IIA that differed quantitatively among three SM fractions were identified by reverse-phase high performance liquid chromatography. Thus, the present findings indicate that the root of SM is an effective inhibitor of Ang II action and has a plural effective constituent, which possess different pharmacological activities on Ang II-induced hypertrophy and hyperplasia in cultured neonatal rat cardiac cells.

The reaction of fullerene C(60) with 4,6-dimethyl-1,2,3-triazine: formation of an open-cage fullerene derivative

A thermal reaction of fullerene C(60) with 4,6-dimethyl-1,2,3-triazine (4) in o-dichlorobenzene gave azacyclohexadiene-fused fullerene derivative 5, by the reaction with intermediate azete 11, and then, after flash chromatography over SiO(2), open-cage fullerene derivative 6 having an eight-membered ring orifice on the C(60) cage. Compound 6 is assumed to be formed via addition of diradical intermediate 13 to C(60). Compound 6 underwent a further photochemical reaction with singlet oxygen with the cleavage of one of the double bonds at the rim of the orifice to afford triketone derivative 8 having a 12-membered ring orifice.

Synthesis and electrochemical properties of novel dimeric fullerenes incorporated in a 2,3-diazabicyclo[2.2.2]oct-2-ene framework

Novel dimeric fullerenes incorporated in a 2,3-diazabicyclo[2.2.2]oct-2-ene framework, with and without direct inter-fullerene-cage bonds, were synthesized and fully characterized spectroscopically; the electronic communication between the two fullerene cages was clarified by differential pulse voltammetry.

The reaction of fullerene C(60) with phthalazine: the mechanochemical solid-state reaction yielding a new C(60) dimer versus the liquid-phase reaction affording an open-cage fullerene

The reaction of fullerene C(60) with phthalazine was studied both in solution and in the solid state using the high-speed vibration-milling technique. The reaction in solution gave open-cage fullerene derivative 1 in 44% yield by a one-pot reaction. In contrast, the solid-state reaction afforded dimeric derivative 2 as the sole product. Dimeric derivative 2 was found to undergo intramolecular [2 + 2] cycloaddtion between the two C(60) cages located in close proximity to give a new C(60) dimer 6 in quantitative yield. The structures of these new derivatives of C(60) were determined by spectroscopic methods, and the electrochemical behavior of 2 and 6 was also studied.

[A case of carbamazepine intoxication with alpha coma and status epilepticus]

We report a 14-year-old girl with carbamazepine intoxication who developed alpha coma and status epilepticus. She fell into deep coma and developed frequent generalized convulsions. The EEG during coma showed diffuse alpha activity predominantly in the frontal area. Serum carbamazepine concentration was 42.8 micrograms/ml. The convulsions were suppressed by diazepam only transiently, and by midazolam completely. Although half a day had passed since carbamazepine ingestion, we could wash out much of drug remnants by gastric lavage. Thereafter, the serum concentration of carbamazepine decreased efficiently and the patient recovered dramatically without complication. Early diagnosis and appropriate treatments should improve the prognosis of carbamazepine intoxication.

Derivatization of fullerene dimer C120 by the Bingel reaction and a 3He NMR study of 3He@C120 monoadducts

Cyclopropanation with diethyl bromomalonate and base (the Bingel reaction) was conducted on fullerene dimer C120 to give a mixture of "monoadducts" (45% yield) and "bisadducts" (< or =37% yield), while 18% of the C120 remained unchanged. The "monoadducts" were separated into five positional isomers, i.e., e(face), e(edge), trans-4, trans-3, and trans-2, by preparative HPLC. Assignments were made based on 1H (and 13C) NMR and confirmed by theoretical calculations of the addends' 1H NMR chemical shifts. The relative yields of these isomers were in fair agreement with those observed for the Bingel bisaddition of C60. The Bingel reaction was also carried out on the dimer C120 encapsulating 3He in one of the C60 cages. Each positional isomer of the "monoadduct" exhibited a pair of 3He NMR signals corresponding to an isomer with functionalization on the 3He-containing cage and the other isomer with functionalization on the empty cage. Using the 3He NMR spectroscopy, a pair of signals for the trans-1 isomer, which eluded detection by 1H NMR, were observed, in addition to pairs of signals for e(face), e(edge), trans-4, trans-3, and trans-2 isomers. The 3He NMR signals for isomers with functionalization on the 3He-containing cage were spread out over a 1.82-ppm range reflecting the direct effects of the addition pattern on the C60 surface. In contrast, the isomers with functionalization on the empty cage exhibited 3He NMR signals that appeared over a 0.14-ppm range, which was shown to be primarily due to changes in the diamagnetism of the functionalized cage based on theoretical calculations of 3He NMR chemical shifts for the model system in which the C60 cage encapsulating 3He was removed.

First synthesis of a highly symmetrical decakis-adduct of fullerene dimer C120

The highly symmetrical decakis-cyclopropanated derivative of C120 was synthesized using template activation and the structure was determined by X-ray crystallography; the decakis-adduct was converted into the eicosa-carboxylic acid derivative that is water soluble.

Analyses of muscular activity, energy metabolism, and muscle fiber type composition in a patient with bilateral masseteric hypertrophy

Hyperwork of the masseter muscles due to habitual parafunction is thought to induce masseteric hypertrophy (so called work hypertrophy). However, the causes underlying this disease are not yet fully understood. Recently, we had a patient with bilateral masseteric hypertrophy, and we performed a partial excision of the masseter muscles. In this patient's case, we examined muscular activity, energy metabolism, and fiber type composition of the masseter muscles using electromyograms (EMG), 31P-magnetic resonance spectroscopy (MRS), and enzyme-histochemistry. The EMG showed no hyperactivity, and the 31P-MRS showed normal energy spectral patterns and PCr contents of the masseter muscles. The fiber type composition, however, in the muscles in this case was very different from that in muscles with "work hypertrophy" and also that in normal masseter muscles: 1. Loss of type IIB fibers; 2. Increases in type IIA and in type IM & IIC fibers; and 3. Decrease in type I fibers. The findings suggest that this is not a case of work hypertrophy but a case of compensatory hypertrophy possibly due to a lack of high-tetanus-tension type IIB fibers.

Endoventricular circular patch plasty for end-stage valvular cardiomyopathy

We present here a case of end-stage non-ischemic valvular dilated cardiomyopathy (DCM) associated with mitral regurgitation (MR). The patient underwent surgery where left ventricular volume reduction using endoventricular circular patch plasty (EVCPP) and mitral valve replacement (MVR) were performed. He has improved much after the operation and is now in New York Heart Association (NYHA) functional class II.

Synchronous recording of load-deformation behaviour and polarized light-microscopic images of the rabbit incisor periodontal ligament during tensile loading

Tooth-periodontal ligament-bone segments were cut in the form of rectangular prisms (1.5 mm wide, 0.65 mm thick, and long enough to allow anchorage of the bone and tooth-end portions in a stretching jig) from the mandibular incisors of 10 rabbits. The experimental set-up enabled simultaneous recording, on video, of the changing image brightness under polarizing optics together with extension across the periodontal ligament. Specimens were stretched until failure at a velocity of 0.5 mm/min. The tensile load-deformation curve of the ligament exhibited an initial, non-linear region that was followed by a linear region, a subsequent yielding region preceding the maximum point, and a final descending region. Gradual increases in the intensity of birefringence in the linear and yielding regions indicated that stress concentrations occur in the supporting fibres attached to mineralized tissues. In the final descending region of the curve, progressive breakages of individual fibre bundles occurred, mainly in the middle zone of the ligament. Analysis of the polarized light-microscopic images showed that the increases in brightness and area of birefringent collagen fibre bundles occurred in parallel with the stress generated. These results suggest that the collagen fibre bundles became aligned with the direction of loading and the intensity of their birefringence increased according to the applied tensile force.

The effects of a high-carbohydrate diet on the stress-strain behavior of the periodontal ligament of the distal root of the mandibular first molar in hamsters

We analyzed stress-strain curves in transverse sections at three different root levels of the cervical, middle, and apical regions of the distal root of the mandibular first molar in hamsters fed a high-carbohydrate (experimental group) or standard (control group) diet for 8 weeks. Each section was loaded in vitro at a rate of 5 mm/min in an extrusive direction. The rupture sites and the structures of birefringent collagen fibers in the periodontal ligament were also analyzed. The maximum shear stress, tangent modulus, and failure strain energy density of the periodontal ligament were significantly greater in the cervical region than in the middle and apical regions in both the control and experimental groups. The maximum shear stress, tangent modulus, and failure strain energy density of the periodontal ligament in the experimental group were significantly lower than those in the control group at the cervical and middle regions. The maximum shear strain was significantly greater in the experimental group than in the control group at the middle and apical regions. Histological sections showed that the periodontal ligament ruptured irregularly in both groups. The collagenous fibers of the ligament in the experimental group appeared to be thinner and less birefringent at the cervical and middle regions of the root. These results suggest that a high-carbohydrate diet differentially affects the collagen fibers in the periodontal ligament as a function of the root level, and that these effects are evident in changes in the mechanical properties of the ligament.