Long-term effects of local pretreatment with alendronate on healing of replanted rat teeth

BACKGROUND AND OBJECTIVE

Our previous study showed that topical alendronate, an inhibitor of bone resorption, reduces root resorption and ankylosis for 21 d after replantation of rat teeth. The aim of the present study was to evaluate the long-term inhibitory effects of topical alendronate in the replanted teeth.

MATERIAL AND METHODS

The rat maxillary first molars were extracted, placed in saline containing 1 mm alendronate (alendronate group) or saline (saline group) for 5 min and then replanted. The maxillae were dissected at 60 and 120 d. Microcomputed tomography horizontal sections at three root levels were analyzed for root and bone resorption, ankylosis and pulp mineralization.

RESULTS

In the alendronate group at 60 and 120 d, the frequencies of resorption of roots and bone were lower than those in the saline group. The p values show statistical significances of lower frequencies in the alendronate group than in the saline group by chi-square test (see Table 1). Ankylosis and pulp mineralization occurred in the alendronate and saline groups. Bone marrow spaces were narrowed in conjunction with bone tissue expansion around the replanted teeth in the alendronate group.

CONCLUSION

The inhibitory effects of topical alendronate were retained on root and bone resorption, but not on ankylosis and pulp mineralization, in the replanted teeth for 4 mo. Alendronate might also stimulate bone formation around the rat replanted teeth.

Degradation of noncollagenous components by neutrophil elastase reduces the mechanical strength of rat periodontal ligament

BACKGROUND AND OBJECTIVE

We have previously shown that increases in neutrophil elastase in periodontal ligament with chronic periodontitis results in degradation of the noncollagenous components. The purpose of this study was to investigate whether the destruction of noncollagenous components by treatment with elastase in vitro causes changes in the mechanical properties of the periodontal ligament.

MATERIAL AND METHODS

The transverse sections of mandibular first molars, prepared from male Wistar rats at 6 wk of age, were digested with 0-50 microg/mL of neutrophil elastase at 37 degrees C for 4 h. Then, their mechanical properties and morphological features were examined.

RESULTS

Digestion with elastase dose-dependently decreased the maximum shear stress and failure strain energy density of the periodontal ligament (p < 0.05-0.01). The histological observations after digestion revealed marked degradation of oxytalan fibers, but no marked changes of the collagen fibers, which was confirmed by the detection of very low quantities of hydroxyproline in the digest. The light and scanning electron micrographs showed that the elastase degraded the interfibrillar substances in the periodontal ligament and exposed individual collagen fibrils.

CONCLUSION

These results suggest that the increased neutrophil elastase observed in periodontal disease degrades the oxytalan fibers and interfibrillar substances in the periodontal ligament to decrease its mechanical strength.

Evaluation of state variable interface between the Activated Sludge Models and Anaerobic Digestion Model no 1

For plant wide modelling of wastewater treatment, it is necessary to develop a suitable state variables interface for integrating state of the art models of ASM and ADM1. ADM1 currently describes such an interface, however, its suitability needs to be experimentally evaluated. In this study, we characterised activated sludge under aerobic and anaerobic conditions to obtain representative state variables for both models. ASM state variables of X(S), X(H) and X(I) (as obtained from aerobic tests) and ADM1 state variables of X(C) and X(I) (as obtained from anaerobic tests) were then correlated to assess the suitability of current interface. Based on the seven datasets of this study and seven datasets from literatures, it was found that in general ASM state variables were well correlated to the state variables of ADM1. The ADM1 state variable of X(C) could be correlated to the sum of state variables of X(S) and X(H), while X(I) in both the models showed direct correspondence. It was also observed that the degradation kinetics of X(C) under anaerobic condition could be better described by individual degradation kinetics of X(S) and X(H). Therefore, to establish a one to one correspondence between ASM and ADM1 state variables and better description of degradation kinetics in ADM1, replacing the composite variable of X(C) by the state variables of X(S) and X(H) is recommended.

Nucleotide sequence analysis of seven Japanese isolates of Plantago asiatica mosaic virus (PlAMV): a unique potexvirus with significantly high genomic and biological variability within the species

The genomic sequences of Plantago asiatica mosaic virus (PlAMV), six lily isolates and one primrose isolate from Japan, were determined. The genomic size of all isolates was 6102 nucleotides, containing the five open reading frames typical of members of the genus Potexvirus. Pairwise comparison analyses confirmed the close relationship between PlAMV and tulip virus X. However, quite low identities were observed between different PlAMV isolates, including foreign isolates; nucleotide sequence identities of the RNA-dependent RNA polymerase (RdRp) gene between a Russian isolate (PlAMV-Ru), a Nandina isolate (PlAMV-Na) and Japanese isolates were 75-77%. These values were the lowest amongst different isolates of the same species of any potexviruses.

Haemostatic Fleece (TachoComb®) to Prevent Intrapleural Adhesions after Thoracotomy: A Rat Model

BACKGROUND

Postoperative adhesion is a complication common to all surgical subspecialties. TachoComb is a collagen fleece with properties well suited to the prevention of adhesion. This preclinical study was performed to evaluate the efficacy and mechanism of action of TachoComb in the prevention of adhesion following pleural injury during thoracic surgery.

METHODS

Rats (n = 72) were randomised to receive saline or TachoComb following pleural injury. The macroscopic severity of adhesion formation and histological changes were assessed following euthanasia at time points up to 28 weeks post-operation. Levels of the biochemical markers t-PA, PAI-1 and bFGF were measured in intrapleural lavage fluid.

RESULTS

The severity of adhesion was lower in TachoComb-treated animals compared with control animals at all time points (mean adhesion score: 1.4 vs. 4 at week 28 post-operation; P < 0.01). Regeneration of the mesothelial cell stratum occurred faster in TachoComb-treated animals, and a significantly lower PAI-1 activity was observed (14.32 vs. 23.28 U/ml; P < 0.01).

CONCLUSIONS

TachoComb is effective in the prevention of adhesion following thoracic surgery, both by acting as a physical barrier and by inhibiting PAI-1 activity.

Cryogenic NMR spectroscopy of endohedral hydrogen-fullerene complexes

We have observed 1H NMR spectra of hydrogen molecules trapped inside modified fullerene cages under cryogenic conditions. Experiments on static samples were performed at sample temperatures down to 4.3 K, while magic-angle-spinning (MAS) experiments were performed at temperatures down to 20 K at spinning frequencies of 15 kHz. Both types of NMR spectra show a large increase in the intramolecular 1H-1H dipolar coupling at temperatures below 50 K, revealing thermal selection of a small number of spatial rotational states. The static and MAS spectra were compared to estimate the degree of sample heating in high-speed cryogenic MAS-NMR experiments. The cryogenic MAS-NMR data show that the site resolution of magic-angle-spinning NMR may be combined with the high signal strength of cryogenic operation and that cryogenic phenomena may be studied with chemical site selectivity.

Wisconsin Card Sorting Test in Parkinson's disease: diffusion tensor imaging

INTRODUCTION

It is generally assumed that executive dysfunctions in Parkinson's disease (PD) are caused by degeneration of the basal ganglia or frontal cortex or both. However, there have been few studies investigating the relationship between executive dysfunctions and cerebral pathological change. The objective of this study was to evaluate various cognitive functions in non-demented patients with PD, and to compare the fractional anisotropy (FA) values of PD patients with and without executive dysfunction.

MATERIALS AND METHODS

Twenty-one consecutive non-demented patients with PD were enrolled in this study. Patients were divided into two groups on the basis of their Wisconsin Card Sorting Test score.

RESULTS

There was significant FA reduction in the left parietal white matter in the group in which the number of categories achieved was <or=2 relative to the group that achieved >2.

CONCLUSION

Accumulating evidence suggests that conventional 'frontal' tasks correlate with both frontal lobe and parietal lobe function, and we suggest that pathological changes in the left parietal lobe may cause, in part, disturbances in executive tasks in PD.

Genome sequence of a Japanese isolate of Radish mosaic virus: the first complete nucleotide sequence of a crucifer-infecting comovirus

The complete nucleotide sequences of RNA1 and RNA2 of a Japanese isolate of Radish mosaic virus (RaMV-J), a crucifer-infecting comovirus, were determined. RNA1 is 6064 nucleotides long and encodes a 210-kDa polyprotein containing conserved motifs that are required for replication. RNA2 is 4020 nucleotides long and encodes a 123-kDa polyprotein containing the putative movement protein and two coat proteins. Comparisons of the encoded proteins confirmed that RaMV-J and a Czech RaMV isolate are isolates of the same species in the genus Comovirus. A phylogenetic analysis of RaMV-J and other comoviruses revealed that legume-infecting comoviruses constitute a single branch to which RaMV is distantly related.

Homologous recombination repair is regulated by domains at the N- and C-terminus of NBS1 and is dissociated with ATM functions

The proteins responsible for radiation sensitive disorders, NBS1, kinase ataxia-telangiectasia-(A-T)-mutated (ATM) and MRE11, interact through the C-terminus of NBS1 in response to the generation of DNA double-strand breaks (DSBs) and are all implicated in checkpoint regulation and DSB repair, such as homologous recombination (HR). We measured the ability of several NBS1 mutant clones and A-T cells to regulate HR repair using the DR-GFP or SCneo systems. ATM deficiency did not reduce the HR repair frequency of an induced DSB, and it was confirmed by findings that HR frequencies are only slightly affected by deletion of ATM-binding site at the extreme C-terminus of NBS1. In contrast, The HR-regulating ability is dramatically reduced by deletion of the MRE11-binding domain at the C-terminus of NBS1 and markedly inhibited by mutations in the FHA/BRCT domains at the N-terminus. This impaired capability in HR is consistent with a failure to observe MRE11 foci formation. Furthermore, normal HR using sister chromatid was completely inhibited by the absence of FHA/BRCT domains. These results suggested that the N- and C-terminal domains of NBS1 are the major regulatory domains for HR pathways, very likely through the recruitment and retention of the MRE11 nuclease to DSB sites in an ATM-independent fashion.

Solid-state NMR of endohedral hydrogen–fullerene complexes

We present an overview of solid-state NMR studies of endohedral H(2)-fullerene complexes, including (1)H and (13)C NMR spectra, (1)H and (13)C spin relaxation studies, and the results of (1)H dipole-dipole recoupling experiments. The available data involves three different endohedral H(2)-fullerene complexes, studied over a wide range of temperatures and applied magnetic fields. The symmetry of the cage influences strongly the motionally-averaged nuclear spin interactions of the endohedral H(2) species, as well as its spin relaxation behaviour. In addition, the non-bonding interactions between fullerene cages are influenced by the presence of endohedral hydrogen molecules. The review also presents several pieces of experimental data which are not yet understood, one example being the structured (1)H NMR lineshapes of endohedral H(2) molecules trapped in highly symmetric cages at cryogenic temperatures. This review demonstrates the richness of NMR phenomena displayed by H(2)-fullerene complexes, especially in the cryogenic regime.

Coexpression of an unusual form of the EWS-WT1 fusion transcript and interleukin 2/15 receptor betamRNA in a desmoplastic small round cell tumour

BACKGROUND

The beta chain of the interleukin 2/15 receptor (IL-2/15Rbeta) is induced by the expression of the EWS-WT1. A case of desmoplastic small round cell tumour (DSRCT) expressing only an unusual EWS-WT1 treated by us is reported here.

AIM

To characterise an unusual form of EWS-WT1.

METHODS

Frozen tissue sections of the axillary tumour were examined using a laser-assisted microdissection technique and reverse transcriptase polymerase chain reaction.

RESULTS

The novel fusion of exon 8 of EWS and the defective exon 10 of WT1 (-KTS) was detected. Although it was an unusual form, the coexpression of the present EWS-WT1, IL-2/15Rbeta and Janus kinase (JAK1) mRNA was detected in the tumour cells. IL-2 and signal transducers and activators of transcription (STAT5) mRNA were detected in both tumour and stromal cells.

CONCLUSION

The induction of the IL-2/15 receptor signalling pathway may contribute to tumorigenesis in DSRCT through a paracrine or an autocrine system, even though the EWS-WT1 was an unusual form.

A single amino acid in the RNA-dependent RNA polymerase of Plantago asiatica mosaic virus contributes to systemic necrosis

From a lily isolate of Plantago asiatica mosaic virus (PlAMV-Li), two sub-isolates (Li1 and Li6) were obtained. Although the nucleotide sequences of Li1 and Li6 were highly conserved, they showed different pathogenicity in Nicotiana benthamiana. Li1 caused necrosis, whereas Li6 infected the plant asymptomatically. Inoculation tests with chimeric and point-mutated viruses revealed that amino acid 1154 of the RNA-dependent RNA polymerase (RdRp) contributes to the necrotic symptoms. The accumulation of the mutant viruses, in which amino acid 1154 of the RdRp was exchanged to the wild-type codon in Li1 and Li6, was almost equal.

Promotion of axonal maturation and prevention of memory loss in mice by extracts of Astragalus mongholicus

BACKGROUND AND PURPOSE

Neurons with atrophic neurites may remain alive and therefore may have the potential to regenerate even when neuronal death has occurred in some parts of the brain. This study aimed to explore effects of drugs that can facilitate the regeneration of neurites and the reconstruction of synapses even in severely damaged neurons.

EXPERIMENTAL APPROACH

We investigated the effects of extracts of Astragalus mongholicus on the cognitive defect in mice caused by injection with the amyloid peptide Abeta(25-35). We also examined the effect of the extract on the regeneration of neurites and the reconstruction of synapses in cultured neurons damaged by Abeta(25-35).

KEY RESULTS

A. mongholicus extract (1 g kg(-1) day(-1) for 15 days, p.o.) reversed Abeta(25-35)-induced memory loss and prevented the loss of axons and synapses in the cerebral cortex and hippocampus in mice. Treatment with Abeta(25-35) (10 microM) induced axonal atrophy and synaptic loss in cultured rat cortical neurons. Subsequent treatment with A. mongholicus extract (100 microg/ml) resulted in significant axonal regeneration, reconstruction of neuronal synapses, and prevention of Abeta(25-35)-induced neuronal death. Similar extracts of A. membranaceus had no effect on axonal atrophy, synaptic loss, or neuronal death. The major known components of the extracts (astragalosides I, II, and IV) reduced neurodegeneration, but the activity of the extracts did not correlate with their content of these three astragalosides.

CONCLUSION AND IMPLICATIONS

A. mongholicus is an important candidate for the treatment of memory disorders and the main active constituents may not be the known astragalosides.

Stress-relaxation and microscopic dynamics of rabbit periodontal ligament

The aim of the present study was to examine the structural basis for the stress-relaxation behaviour of the periodontal ligament (PDL). Seventeen 4-month-old rabbits were used. A tooth-PDL-bone segment was cut in a rectangular prism from the incisor of a dissected mandible. The specimen was mounted in a testing machine built on a video stereomicroscope. Following preconditioning, each specimen was stretched to a deformation of 35 microm and then the deformation was kept constant for 300 s to obtain a stress-relaxation curve. Thereafter, stress-relaxation tests were repeated sequentially at deformations of 55, 75, and 95 microm. Polarised-light video-stereomicroscopic images of the specimens were simultaneously recorded and analysed with the stress-relaxation curves. The image analysis revealed that during stress-relaxation, the brightness of the birefringent fibres tended to initially increase rapidly and then do so gradually. There were negative correlations between the brightness and relaxation modulus at the four deformations. The decreases of normalised relaxation modulus for 300 s were less at greater deformation levels. The stress-relaxation process was well described by a function with three exponential decay terms and a constant. These findings suggest that during stress-relaxation of the PDL, the alignment of the collagen molecules and fibrils within the stretched fibres may occur, which could be driven by the strain energy imparted to the specimen on initial stretching.

An approach for substrate mapping between ASM and ADM1 for sludge digestion

Kinetic modelling of the hydrolysis stage of municipal activated sludge, which is presumed to be the rate-limiting step in the anaerobic sludge digestion process, was studied by measuring methane production rate (MPR) in anaerobic batch tests. The MPR curves revealed that the degradable organic components in municipal sludge could be classified into two fractions having different kinetics. The first fraction (XS1) constituted about 55% of the sludge COD and degraded with first-order kinetics. The second fraction (XS2), which degraded during the initial phase, accounted for about 21% of sludge COD. The degradation kinetics for XS2 was expressed by Contois-type equation with respect to concentration of substrate in the fed sludge and that of active biomass in the mixture. Simultaneous batch aerobic respirometric tests showed that the activated sludge was composed of 53% heterotrophic biomass (XH-Aerobe) COD and 20% of slowly biodegradable COD (XS), that had same kinetic expressions as observed in the batch anaerobic tests. The observed correlation between substrate fractions suggests XS1 and XS2 could be directly mapped to the aerobic state variables of XH-Aerobe and Xs respectively. The degradation of XS1 seems to be anaerobic decay of XH-Aerobe while XS2 is thought to be hydrolysis of XS by microcosm of the sludge.

Nijmegen breakage syndrome and functions of the responsible protein, NBS1

Nijmegen breakage syndrome (NBS) is a rare recessive genetic disorder, characterized by bird-like facial appearance, early growth retardation, congenital microcephaly, immunodeficiency and high frequency of malignancies. NBS belongs to the so-called chromosome instability syndromes; in fact, NBS cells display spontaneous chromosomal aberrations and are hypersensitive to DNA double-strand break-inducing agents, such as ionizing radiations. NBS1, the gene underlying the disease, is located on human chromosome 8q21. The disease appears to be prevalent in the Eastern and Central European population where more than 90% of patients are homozygous for the founder mutation 657del5 leading to a truncated variant of the protein. NBS1 forms a multimeric complex with MRE11/RAD50 nuclease at the C-terminus and retains or recruits them at the vicinity of sites of DNA damage by direct binding to histone H2AX, which is phosphorylated by PI3-kinase family, such as ATM, in response to DNA damage. Thereafter, the NBS1-complex proceeds to rejoin double-strand breaks predominantly by homologous recombination repair in vertebrates. NBS cells also show to be defective in the activation of intra-S phase checkpoint. We review here some cellular and molecular aspects of NBS, which might contribute to the clinical symptoms of the disease.

New strategy of therapy for functional dyspepsia using famotidine, mosapride and amitriptyline

BACKGROUND

In functional gastrointestinal (GI) disorders including functional dyspepsia (FD) and irritable bowel syndrome (IBS), there might be no small extent of contributions of psychosomatic factors. As a therapy for IBS patients, the effectiveness of antidepressants has been reported.

AIM

In this study, we evaluated the efficacy of H2-receptor antagonist (famotidine) and 5-HT4 receptor agonist (mosapride citrate). In addition, the effect of antidepressants was assessed as the second-step therapy.

METHODS

Patients complaining upper GI symptoms were diagnosed as FD excluding organic diseases. Randomized patients received 20 mg/day of famotidine or 15 mg/day of mosapride citrate for 4 weeks and the efficacy was compared between the two groups based on a 10-point visual analogue scale. When symptoms were not relieved (score improvement 0-2 points), patients received amitriptyline (30 mg/day) or no medication for 4 weeks randomly. Patients who had depression in psychological test (SDS) were omitted.

RESULTS

As the first-step therapy, both famotidine and mosapride showed beneficial effects regardless of FD subtypes, age and gender. The efficacy of these two drugs in relieving FD symptoms was not significantly different. In patients who failed in the first-step therapy, amitriptyline showed beneficial effects.

CONCLUSIONS

These findings might be clinically important in view of the efficient relief of symptoms in FD patients.

Full-scale application of anaerobic digestion process with partial ozonation of digested sludge

For improving sludge digestion and biogas recovery, a new anaerobic digestion process combined with ozonation was tested at a full-scale unit for 2 years and its performance was compared with a simultaneously operated conventional anaerobic digestion process. The new process requires two essential modifications, which includes ozonation for enhancing the biological degradability of sludge organics and concentrating of solids in the digester through a solid/liquid separation for extension of SRT. These modifications resulted in high VSS degradation efficiency of ca. 88%, as much as 1.3 times of methane production and more than 70% reduction in dewatered sludge cake production. Owing to accumulation of inorganic solids in the digested sludge, water content of the dewatered sludge cake also reduced from 80% to 68%. An energy analysis suggested that no supplemental fuel was necessary for the subsequent incineration of the cake from the new process scheme. The process is suitable to apply to a low-loaded anaerobic digestion tank, where power production is used.

Minimization of greenhouse gas emission by application of anaerobic digestion process with biogas utilization

To assess the impact on greenhouse gas emission, different process schemes for municipal sludge treatment were evaluated based on the data from pilot-scale experiments and review of annual operation reports. A modified anaerobic digestion process with partial ozonation of digested sludge to improve biological degradability and the conventional anaerobic digestion process were compared with respect to the energy demand in each process schemes. Options for beneficial use of biogas included (1) application of biogas for power production and (2) recovery as an alternative to natural gas utilization. The analysis indicated that the partial ozonation process with power production led to minimal greenhouse gas emission because the extra energy production from this scheme was expected to cover all of the energy demand for the plant operation. Moreover, the final amount of dewatered sludge cake was only 40% of that expected from the conventional process, this significantly minimizes the potential for greenhouse gas emission in the subsequent sludge incineration processes.

Effects of alendronate on restoration of biomechanical properties of periodontium in replanted rat molars

OBJECTIVE

We examined the effect of the pretreatment of roots with alendronate on the restoration of the support function of the healing periodontal ligament in replanted rat molars.

METHODS

The left maxillary first molars were extracted, placed in 0.9% NaCl containing 1 mm alendronate (alendronate group) or 0.9% NaCl (control group) for 5 min, and were replanted into their sockets. Groups of animals were killed at 7, 14, and 21 days after replantation. Normal control rats were also killed on the same days. The force required to extract the replanted or normal tooth from its socket was measured, and a load-deformation curve was developed and analyzed. Micro-computed tomography and histologic analyses were also made.

RESULTS

The mechanical properties of the healing periodontal ligament in the alendronate group were gradually restored from 7 to 21 days. However, fractures of the roots and bones during mechanical testing occurred in most of the replanted teeth in the control group at 21 days. The rates of restoration of the mechanical strength, extensibility, stiffness, and toughness for the alendronate group at 21 days were 67, 98, 74, and 68% of the normal controls, respectively. Micro-computed tomography and histologic observations revealed that bone-like structures within the pulp and ankylosis between the roots and socket bones occurred commonly in the control group, but were uncommon in the alendronate group.

CONCLUSIONS

Our findings suggest that the pretreatment with alendronate inhibits the formation of abnormal mineralized tissues and results in better restoration of the support function of the healing periodontal ligament in replanted teeth.

Effects of age on the stress–strain and stress–relaxation properties of the rat molar periodontal ligament

OBJECTIVE

We examined the stress-strain and stress-relaxation properties of the periodontal ligament (PDL) in the rat molar at 2, 6, 12, and 24 months of age to elucidate age-related changes in the tooth support function of the PDL.

DESIGN

From the dissected left and right mandibles in each rat, a pair of transverse sections (ca. 0.45 mm in thickness) of the first molar was cut at the middle part of the mesial root. We then obtained a load-deformation curve for the PDL, using one of the paired sections. The other section was loaded to as much as 50% of the maximum load as determined from the contralateral section, and keeping the deformation constant for 10 min, a load-relaxation curve was obtained and analysed.

RESULTS

The maximum shear stress and tangent modulus decreased between 2 and 24 months of age. As the maximum shear strain increased with age (P < 0.001), the failure strain energy density did not change between 2 and 24 months of age. The stress-relaxation during the 10 min period decreased from 2 to 24 months of age (P < 0.01). The relaxation process of the PDL in each age was well described by a sum of three exponential decay functions. The age-related decrease in the relaxation was found to be mainly due to the increase in the relaxation time for the long-term relaxation component.

CONCLUSION

These results indicate that the maximum shear stress and stiffness of the rat molar PDL decrease between 2 and 24 months of age; but its toughness remains unchanged due to an increase in the extensibility. Our findings further indicate that the fluid flow and movements of macromolecules within the stretched PDL fibres during the stress-relaxation decrease with advancing age.

Relationship between the tooth eruption and regional blood flow in angiotensin II-induced hypertensive rats

OBJECTIVE

The mechanism of action of vasoactive drugs on tooth movement is unknown. The purpose of the present study was to measure simultaneously the axial movement of the mandibular incisor, regional blood flow at the base of the incisor, and systemic arterial blood pressure in angiotensin II-induced hypertensive rats to determine the possible cause of tooth displacement.

DESIGN

The measurements were made under artificial respiration with halothane anaesthesia. In the experimental animals, 2.5 microg of angiotensin II in 1 ml of Ringer's solution was infused at 0.83 ml/h for 12 h from the femoral vein. In the control animals, only Ringer's solution was infused.

RESULTS

Angiotensin II caused an increase of the mean arterial blood pressure from 86 to 119 mm Hg, and decreases of the eruption rate from 667 to 494 microm/24 h and the regional blood flow from 262 to 214 mV. There was a positive correlation between the eruption rate and regional blood flow, and a negative correlation between the blood pressure and regional blood flow.

CONCLUSION

These results suggest that angiotensin II caused constriction of the peripheral vascular smooth muscle resulting in an increase of arterial blood pressure and a decrease of regional blood flow, followed by a decrease of fluid volume and then a reduction of either the pressure within the socket or of the eruptive force. We assume that the regional vascular pressure within the socket plays an important role in determining the position of the rat incisor.

Age-related and regional differences in the stress–strain and stress–relaxation behaviours of the rat incisor periodontal ligament

Groups of rats were killed at 2, 6, 12, and 24 months of age. From dissected left and right mandibles in each rat, three pairs of transverse sections were cut at the incisal, middle, and basal regions of the incisor. One section in each pair was loaded until failure and a stress-strain curve for the periodontal ligament (PDL) was obtained. The other section was loaded to up to 50% of the maximum shear stress as determined from the contralateral section and then kept at a constant strain for 10 min, to obtain the stress-relaxation curve at the same region of the PDL. The maximum shear stress and toughness increased with age at the incisal region and the maximum shear strain increased with age at the incisal and middle regions. The tangent modulus decreased with advancing age at the middle region. The stress-relaxation during 10 min decreased with advancing age at the incisal and basal regions, but not at the middle region. The relaxation process was well described by a sum of three exponential decay functions, reflecting the short-, medium-, and long-term relaxation components. The age-related decrease in the relaxation was mainly attributable to increases in the ratio and relaxation time of the long-term relaxation component. These results suggest that with advancing age the mechanical strength and toughness of the PDL are enhanced mostly at the incisal region and that the viscous fraction is relatively decreased at the incisal and basal regions along the long axis of the rat incisor.

Process performance and change in sludge characteristics during anaerobic digestion of sewage sludge with ozonation

A new process configuration combining anaerobic digestion with ozonation, and operated at long SRT, was studied with the objective of on-site reduction in sludge quantity and improving biogas recovery. The process performance with respect to solid reduction efficiency and other important process parameters like accumulation of inorganic solids, changes in sludge viscosity and dewatering characteristics were evaluated from the data of long term pilot scale continuous experiments conducted using a mixture of primary and secondary municipal sewage sludge. Due to sludge ozonation and long SRT, high VSS degradation efficiency of approximately 80% was achieved at a reactor solid concentration of 6.5%. A high fraction of inorganic solid (>50%) consisting mainly of acid insoluble and iron compounds was found to accumulate in the reactor. The high inorganic content accumulated in the digested sludge did not, however, contribute to the observed increase in sludge viscosity at high solid concentration. The sludge viscosity was largely found to depend on the organic solid concentration rather than the total solid content. Moreover, higher inorganic content in the digested sludge resulted in better sludge dewaterability. For a quick assessment of the economic feasibility of the new process, an economic index based on the unit cost of digested sludge disposal to unit electric cost is proposed.

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.