Development of Rat Caries-Induced Pulpitis Model for Vital Pulp Therapy

Rodent animal models for vital pulp therapy are commonly used in dental research because their tooth anatomy and cellular processes are similar to the anatomy and processes in humans. However, most studies have been conducted using uninfected sound teeth, which makes it difficult to adequately assess the inflammatory shift after vital pulp therapy. In the present study, we aimed to establish a caries-induced pulpitis model based on the conventional rat caries model and then evaluate inflammatory changes during the wound-healing process after pulp capping in a model of reversible pulpitis induced by carious infection. To establish the caries-induced pulpitis model, the pulpal inflammatory status was investigated at different stages of caries progression by immunostaining targeted to specific inflammatory biomarkers. Immunohistochemical staining revealed that both Toll-like receptor 2 and proliferating cell nuclear antigen were expressed in moderate and severe caries-stimulated pulp, indicating that an immune reaction occurred at both stages of caries progression. M2 macrophages were predominant in moderate caries-stimulated pulp, whereas M1 macrophages were predominant in the severe caries-stimulated pulp. Pulp capping in teeth with moderate caries (i.e., teeth with reversible pulpitis) led to complete tertiary dentin formation within 28 d after treatment. Impaired wound healing was observed in teeth with severe caries (i.e., teeth with irreversible pulpitis). During the wound-healing process in reversible pulpitis after pulp capping, M2 macrophages were predominant at all time points; their proliferative capacity was upregulated in the early stage of wound healing compared with healthy pulp. In conclusion, we successfully established a caries-induced pulpitis model for studies of vital pulp therapy. M2 macrophages have an important role in the early stages of the wound-healing process in reversible pulpitis.

Novel Functional Peptide for Next-Generation Vital Pulp Therapy

Although vital pulp therapy should be performed by promoting the wound-healing capacity of dental pulp, existing pulp-capping materials were not developed with a focus on the pulpal repair process. In previous investigations of wound healing in dental pulp, we found that organic dentin matrix components (DMCs) were degraded by matrix metalloproteinase-20, and DMC degradation products containing protein S100A7 (S100A7) and protein S100A8 (S100A8) promoted the pulpal wound-healing process. However, the direct use of recombinant proteins as pulp-capping materials may cause clinical problems or lead to high medical costs. Thus, we hypothesized that functional peptides derived from recombinant proteins could solve the problems associated with direct use of such proteins. In this study, we identified functional peptides derived from the protein S100 family and investigated their effects on dental pulp tissue. We first performed amino acid sequence alignments of protein S100 family members from several mammalian sources, then identified candidate peptides. Next, we used a peptide array method that involved human dental pulp stem cells (hDPSCs) to evaluate the mineralization-inducing ability of each peptide. Our results supported the selection of 4 candidate functional peptides derived from proteins S100A8 and S100A9. Direct pulp-capping experiments in a rat model demonstrated that 1 S100A8-derived peptide induced greater tertiary dentin formation compared with the other peptides. To investigate the mechanism underlying this induction effect, we performed liquid chromatography-tandem mass spectrometry analysis using hDPSCs and the S100A8-derived peptide; the results suggested that this peptide promotes tertiary dentin formation by inhibiting inflammatory responses. In addition, this peptide was located in a hairpin region on the surface of S100A8 and could function by direct interaction with other molecules. In summary, this study demonstrated that a S100A8-derived functional peptide promoted wound healing in dental pulp; our findings provide insights for the development of next-generation biological vital pulp therapies.

Effects of fermented soymilk with Lactobacillus casei Shirota on skin condition and the gut microbiota: a randomised clinical pilot trial

Several clinical studies have shown that isoflavones and Lactobacillus casei Shirota (LcS) have beneficial effects on skin condition and the gut microbiota, respectively. Thus, we investigated the effects of consecutive intake of fermented soymilk (FSM) with LcS on skin condition and the gut microbiota, as well as isoflavone bioavailability, in a randomised, double-blind, placebo-controlled trial as a pilot study. Sixty healthy premenopausal Japanese women received FSM containing a moderate level of isoflavone aglycones and a probiotic LcS, or soymilk (SM) containing neither of them, twice a day for 8 weeks. Skin condition was assessed by a subjective questionnaire for face and morphological analysis of the stratum corneum on the inner forearm. Faecal microbiota and urinary isoflavone were analysed by 16S rRNA gene amplicon sequencing and high-performance liquid chromatography tandem mass spectrometry, respectively. Both the FSM and SM groups had improved skin condition as assessed from scores of overall satisfaction, dryness, moisture, elasticity, coarseness, pigmentation and/or stratum corneum morphology, as well as significantly increased levels of urinary isoflavones during the intake period compared with the pre-intake period, although there were no significant differences between the two groups. There was a significant positive correlation between urinary isoflavone levels and skin questionnaire scores. In contrast, the relative abundance levels of Lactobacillaceae significantly increased and those of Bifidobacteriaceae tended to increase during the intake period compared with the pre-intake period. For the after-intake period they only decreased significantly in the FSM group. The levels of Enterobacteriaceae and Porphyromonadaceae significantly decreased during the intake period in the FSM group. These findings suggest that daily intake of FSM, as well as SM, provides health benefits that improve skin condition via increased levels of isoflavone absorption in the body, and that only FSM beneficially modifies the gut microbiota in premenopausal healthy women.

Discontinuation of leisure time impact-loading exercise is related to reduction of a calcaneus quantitative ultrasound parameter in young adult Japanese females: a 3-year follow-up study

A 3-year follow-up study on 334 young Japanese females enrolled in a university at the age of 18 years revealed that discontinuation of leisure time impact-loading exercises performed in junior high and/or high school was associated with increased risk of reduction in calcaneus osteo-sono assessment index (OSI).

INTRODUCTION

Bone strength rapidly increases during puberty and reaches its peak by the end of adolescence. The aim of this study was to determine the lifestyle factors that influence the maintenance of calcaneus OSI in young adult females around the time when peak bone mass is attained.

METHODS

Annual health checkups including OSI measurements, anthropometrics, lifestyle analysis, and blood examination were performed 4 times on 334 Japanese females enrolled in a university at the age of 18 years. According to the slope of OSI change during the 3-year follow-up, the subjects were grouped into two categories: OSI loss (the lowest tertile) and OSI gain/stable (the second and third tertiles).

RESULTS

At the baseline assessment, the OSI loss group had higher OSI and height and an earlier menarche age than the OSI gain/stable group. Performing leisure time impact-loading exercise in junior high and/or high school but discontinuing it at university was associated with increased risk of OSI loss, independent of OSI, height and weight at the age of 18 years, weight change during follow-up, age of menarche, energy-adjusted nutrient intake, and alcohol drinking; the odds ratios were 4.1-4.9 compared with those performing impact-loading exercise at university. In particular, duration, frequency, and subjective intensity of impact-loading exercise during high school were positively associated with OSI loss.

CONCLUSION

Discontinuation of leisure time impact-loading exercises performed during late adolescence is associated with an increased risk of OSI loss in young adult females during the 3-year follow-up period.

The role of osteocytes in bone resorption during orthodontic tooth movement

We investigated the roles of osteocytes in osteoclastic bone resorption during orthodontic tooth movement using the transgenic mice in which osteocytes can be specifically ablated. Because these transgenic mice express the receptor for diphtheria toxin on the cell surfaces of osteocytes, the injection of diphtheria toxin can ablate their osteocytes in vivo. Injection of diphtheria toxin into the transgenic mice significantly increased the number of ablated osteocytes in alveolar bone compared with that in wild-type mice with or without diphtheria toxin injection. Increased numbers of ablated osteocytes were observed from day 4 to day 12 after the injection in alveolar bones as well as in cortical bone of the tibiae. We applied the orthodontic force 4 days after the injection of diphtheria toxin, and the distance of tooth movement on day 12 was significantly smaller in transgenic mice than that in control mice. The numbers of osteoclasts and the quantity of eroded bone surface at the compression site were significantly reduced in the transgenic mice injected with diphtheria toxin than in control mice. These results provide in vivo demonstration of osteocyte involvement in osteoclastic bone resorption during orthodontic tooth movement.

Application of MRI movie for observation of articulatory movement during a fricative /s/ and a plosive /t/

OBJECTIVE

To use an accurate method of tooth visualization in magnetic resonance imaging (MRI) movie for the observation of spatio-temporal relationships among articulators.

MATERIALS AND METHODS

The subjects were two volunteers. Each subject repeated a vowel-consonant-vowel syllable (ie, /asa/; /ata/), and the run was measured using a gradient echo sequence. A custom-made clear retainer filled with the jelly form of ferric ammonium citrate was then fit onto the dental arch, and a T1-weighted turbo-spin-echo sequence was taken. Landmarks were used for superimposition of the incisor boundary onto sequential images of MRI movie. Tracings were conducted to observe the spatio-temporal relationships among articulators.

RESULTS

The incisor boundary was clearly visible in the magnetic resonance images. After superimposition, the contact distance of the tongue to palate/incisor was found to be longer during /t/-articulation than during /s/-articulation. There were prominent differences in images with and without tooth superimposition in the front oral cavity.

CONCLUSIONS

The method could distinctly extract a tooth boundary in MRI. Detailed configurational relationships between the tongue and tooth were observed during the production of a fricative and a plosive in MRI movie using this method.

Correlation between genotype and supernumerary tooth formation in cleidocranial dysplasia

INTRODUCTION

Cleidocranial dysplasia (CCD, MIM#119600), for which the responsible gene is RUNX2, is a genetic disorder characterized by hypoplasia or aplasia of the clavicles, patent fontanelles, and a short stature. Supernumerary teeth and delayed eruption and impaction of permanent teeth are frequently associated with CCD. Our previous study reported wide intrafamilial variation in supernumerary tooth formation associated with a mutation in the RUNT-domain of RUNX2, suggesting a low correlation between the genotype and supernumerary tooth formation. To further clarify this point, a more precise evaluation was performed.

DESIGN

Gene mutational analysis of nine Japanese individuals with CCD was performed. Dental and skeletal characteristics were examined based on patient examinations and radiographs.

RESULTS

Four different gene mutations, including one novel mutation in RUNX2 gene (NM_001024630), were identified. Among them, four individuals had the R225Q mutation, three siblings had the P224S mutation, and the other two individuals had different frame-shift mutations. Wide variations in supernumerary tooth formation were observed in individuals with identical gene mutations, and discordance was seen between monozygotic twins. Asymmetric supernumerary tooth formation was noted in five out of the nine individuals.

CONCLUSION

Individuals with identical gene mutations showed a wide variation in the supernumerary tooth formation. Not only the genotype but also environmental factors and a complex system including epigenetics and copy number variation might regulate supernumerary tooth formation in CCD.

Non-syndromic Oligodontia with a Novel Mutation of PAX9

Agenesis of the permanent teeth is a congenital anomaly that is frequently seen in humans. Oligodontia is a severe type of tooth agenesis involving 6 or more congenitally missing teeth, excluding the third molars. Previous studies have indicated that mutations in the homeobox gene MSX1, paired domain transcription factor PAX9, and EDA are associated with non-syndromic oligodontia. This study reports a Japanese family (eight of 14 family members affected) with non-syndromic oligodontia who preferentially lacked molar teeth. In this family, a novel frameshift mutation (321_322insG) was identified in the paired domain of PAX9. The frameshift mutation caused altered amino acids in the paired domain and premature termination of translation by 26 amino acids. When transfected into COS-7 cells, the mRNA expression of 321_322insG PAX9 was comparable with that of wild-type PAX9. However, the mRNA of 321_322insG PAX9 was more unstable than that of wild-type PAX9. This mRNA instability caused a marked decrease in protein production, as evaluated by Western blot analysis and immunostaining. These findings suggest that the 321_322insG mutation causes insufficient function of PAX9 protein and haploinsufficiency as a genetic model of familial non-syndromic oligodontia with a PAX9 mutation.

A Mongolian patient with hypohidrotic ectodermal dysplasia with a novel P121S variant in EDARADD

INTRODUCTION

Hypohidrotic ectodermal dysplasia is a genetic disorder characterized by diminished or a lack of sweating, congenital missing teeth, and sparse or absent hair. Three genes, EDA, EDAR, and EDARADD, all related to tumor necrosis factor signaling, have been reported as responsible genes for this disorder. Among them, the largest numbers of mutations have been identified in EDA, and only two mutations identified in EDARADD.

MATERIALS AND METHODS

DNA analysis of EDA, EDAR, and EDARADD was performed on a Mongolian patient by polymerase chain reaction-direct sequencing.

RESULTS

The 5-year-old Mongolian individual had no erupted deciduous or permanent teeth. A panoramic radiograph showed only one tooth in the right mandible. His hair and eyebrows were sparse, but he did not have a short stature. He showed diminished sweating. The nails of his fingers and toes were normal. Based on these conditions, he was diagnosed with hypohidrotic ectodermal dysplasia. There was no gene mutation of EDA or EDAR. A novel heterozygous variant (P121S; c.361C>T) was identified in the death domain of EDARADD (NM_080738). No other member of his family was affected, and this variant was not identified in his parents or maternal grandparents.

CONCLUSION

This study reports an individual affected with hypohidrotic ectodermal dysplasia with a novel heterozygous P121S variant in the death domain of EDARADD.

Control of cellular adhesiveness in an alginate-based hydrogel by varying peroxidase and H(2)O(2) concentrations during gelation

An aqueous solution of alginate possessing phenolic hydroxyl (Alg-Ph) groups is gellable via a horseradish peroxidase (HRP)-catalyzed oxidative crosslinking reaction between Ph groups, consuming H(2)O(2) as an electron acceptor. This study evaluates the effect of H(2)O(2) and HRP concentrations on cellular adhesiveness and proliferation on the resultant enzymatically crosslinked Alg-Ph gels. After 4h of seeding, 81.1% of L929 fibroblast cells adhere to an Alg-Ph hydrogel prepared with 1 U ml(-1) HRP and 1mM H(2)O(2). Increasing the concentration of H(2)O(2) to 15 mM decreases the percentage of adhering cells to 28.4%. The cellular adhesion at this H(2)O(2) concentration is increased to 82.6% by increasing the HRP concentration to 10 U ml(-1). The cells adhering to the Alg-Ph hydrogels with higher cellular adhesiveness establish a confluent monolayer during 168 h of culture. A cell sheet can then be harvested within 5 min of immersion in a medium containing alginate lyase at 1.0 mg ml(-1). The harvested cell sheet re-adhere, and the cells contained in the sheet proliferate after being transferred to another cell culture dish.

Acceleration of palatal wound healing in Smad3-deficient mice

Wound healing is a well-orchestrated complex process leading to the repair of injured tissues. It is suggested that transforming growth factor (TGF)-beta/Smad3 signaling is involved in wound healing. The purpose of this study was to investigate the role of TGF-beta/Smad3 signaling in palatal wound healing in Smad3-deficient (Smad3(-/-)) mice. Histological examination showed that wound closure was accelerated by the proliferation of epithelium and dermal cells in Smad3(-/-) mice compared with wild-type (WT) mice. Macrophage/monocyte infiltration at wounded regions in Smad3(-/-) mice was decreased in parallel with the diminished production of TGF-beta1, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1alpha compared with WT mice. Fibrocytes, expressing hematopoietic surface marker and fibroblast products, were recruited and produced alpha-smooth-muscle actin in WT mice, but were not observed in Smad3(-/-) mice. These results suggest that TGF-beta/Smad3 signaling may play an important role in the regulation of palatal wound healing.

In vivo application of amelogenin suppresses root resorption

Amelogenin is recognized as an enamel protein associated with enamel formation. Besides this well-known function, remarkable root resorption has been seen in amelogenin-null mutant mice. Moreover, in vitro culture studies showed that amelogenin suppressed osteoclast differentiation. These studies raised the hypothesis that amelogenin can inhibit root resorption by reducing odontoclast number. To examine this hypothesis, we applied porcine amelogenins in a rat root resorption model, in which maxillary first molars were replanted after being air-dried. Compared with untreated and carrier-treated tooth roots, the application dramatically reduced the odontoclast number on root surfaces and inhibited cementum and root dentin resorption. Amelogenin significantly reduced the number of human odontoclastic cells in culture. It also inhibited RANKL expression in mouse bone marrow cell cultures. All these findings support our hypothesis that amelogenin application suppresses root resorption by inhibiting odontoclast number, and suggest that this is mediated by the regulation of RANKL expression.

Atelocollagen-mediated local and systemic applications of myostatin-targeting siRNA increase skeletal muscle mass

RNA interference (RNAi) offers a novel therapeutic strategy based on the highly specific and efficient silencing of a target gene. Since it relies on small interfering RNAs (siRNAs), a major issue is the delivery of therapeutically active siRNAs into the target tissue/target cells in vivo. For safety reasons, strategies based on vector delivery may be of only limited clinical use. The more desirable approach is to directly apply active siRNAs in vivo. Here, we report the effectiveness of in vivo siRNA delivery into skeletal muscles of normal or diseased mice through nanoparticle formation of chemically unmodified siRNAs with atelocollagen (ATCOL). ATCOL-mediated local application of siRNA targeting myostatin, a negative regulator of skeletal muscle growth, in mouse skeletal muscles or intravenously, caused a marked increase in the muscle mass within a few weeks after application. These results imply that ATCOL-mediated application of siRNAs is a powerful tool for future therapeutic use for diseases including muscular atrophy.

Diversity of supernumerary tooth formation in siblings with cleidocranial dysplasia having identical mutation in RUNX2 : possible involvement of non-genetic or epigenetic regulation

INTRODUCTION

Cleidocranial dysplasia (CCD, MIM #119600) is an autosomal-dominant disorder characterized by hypoplasia or aplasia of clavicles, patent fontanelles and short stature. The responsible gene has been identified as RUNX2. CCD is also accompanied by characteristic dental abnormalities, e.g. supernumerary teeth, delayed eruption and impaction of permanent teeth. Intrafamilial variations of skeletal abnormalities are reported but those of dental abnormalities are obscure. To clarify this point, a precise examination of the dental features of CCD siblings having identical mutation was performed.

DESIGN

Gene mutational analysis of three Japanese CCD siblings and their father was performed. Skeletal and dental characteristics were examined by the inquiry and radiographs.

RESULTS

Three siblings uniformly showed patent fontanelles and short stature. They and their father had a novel missense mutation in the RUNT-domain (P210S) of RUNX2. The siblings were completely discordant for the dental characteristics with the position and number of supernumerary teeth being completely different. The youngest, a 12-year-old boy, had six supernumerary teeth, which appeared symmetrically around the maxillary canines and mandibular premolars. The second, a 15-year-old girl, had four supernumerary teeth which appeared around the mandibular incisors. The oldest, a 17-year-old boy, had 11 supernumerary teeth, which were symmetrically around the mandibular lateral dentition and asymmetrically around the maxillary incisors and premolars.

CONCLUSION

The present study suggests the involvement of non-genetic or epigenetic regulation in supernumerary tooth formation in CCD.

Identification of genes related to mechanical stress in human periodontal ligament cells using microarray analysis

BACKGROUND AND OBJECTIVE

Differential expression of genes in human periodontal ligament (PDL) under mechanical stress, such as orthodontic force, is thought to be involved in the remodeling of PDL cells and periodontal tissues. However, little is known about the genes expressed in PDL cells under mechanical stress.

MATERIAL AND METHODS

We employed microarray analysis to assess, in a comprehensive manner, the gene expression profiles in PDL cells compressed by a static force using an in vitro three-dimensional culture system. Six genes were selected and validated by quantitative real-time polymerase chain reaction analysis, consistent with the microarray data.

RESULTS

The microarray data revealed that 108 of 30,000 genes tested were differentially expressed by mechanical force loading. Among them, 85 genes were up-regulated by mechanical stress, while 23 genes were down-regulated, judging by the thresholds of a two-fold increase/decrease compared with the controls. Thirty-two of the up-regulated and eight of the down-regulated genes, well-characterized in protein function, were involved in numerous biological processes including cell communication, cell signaling, cell cycle, stress response, and calcium release. However, several genes differentially expressed in our microarray data have not been well defined as stress-response molecules.

CONCLUSION

Our microarray is the first to show the gene profile in PDL cells caused by mechanical stress; however, further studies to clarify the physiological function of these molecules in PDL cells are required.

Development of the fast neutron standard using a Be({alpha},n) reaction at the National Metrology Institute of Japan

This paper describes the 8-MeV neutron field where the neutrons are generated in the (9)Be(alpha,n)(12)C reaction by bombardment of a beryllium target with a 2.4-MeV (4)He(+) beam from a Van de Graaff accelerator. The neutron field is being prepared for a new national standard on neutron fluence in Japan. Absolute measurement of the neutron fluence was taken using a proton recoil neutron detector, consisting of a silicon surface barrier detector with a polyethylene radiator. Neutron spectra were measured using a newly developed recoil proton spectrometer and a liquid organic scintillation detector. The gamma rays existing in the field were also characterised using a liquid organic scintillation detector. The ambient dose equivalents of the gamma rays were estimated to be <100 microSv at the neutron fluence of 10(7) neutrons cm(-2).

Leukotrienes mediate 5-hydroxytryptamine-induced plasma extravasation in the rat knee joint via CysLT-type receptors

OBJECTIVE AND DESIGN

The aim of this study was to investigate whether leukotrienes synthesized by 5-lipoxygenase (5-LO) and acting via leukotriene (LT) receptors contribute to 5-hydroxytryptamine (5-HT)-induced knee joint plasma extravasation (PE).

MATERIALS AND METHODS

Knee joints of rats under anesthesia were perfused with 5-HT and synovial vascular Evans Blue dye leakage was measured spectrophotometrically. A series of 5-LO inhibitors and LT receptor antagonists were investigated for their ability to inhibit 5-HT-induced synovial PE.

RESULTS

Inhibitors of 5-LO (NDGA and REV 5901) significantly attenuated 5-HT-induced plasma extravasation. MK 571, LY 171883, BAY u9773 (CysLT receptor antagonists) and REV 5901 (a CysLT receptor antagonist and a 5-LO inhibitor) were equally effective in inhibiting 5-HT-induced PE, indicating that leukotrienes mediate 5-HT-induced PE via CysLT receptors. In contrast, antagonists selective for LTB(4) receptors (BLT(1) and BLT(2) receptors) failed to reduce 5-HT-induced PE.

CONCLUSIONS

These results demonstrate that leukotrienes, specifically cysteinyl-leukotrienes contribute to synovial plasma extravasation and suggest that leukotrienes act downstream of 5-HT in the inflammatory cascade.

Recombinant monoclonal thyrotropin-stimulation blocking antibody (TSBAb) established from peripheral lymphocytes of a hypothyroid patient with primary myxedema

Anti-TSH receptor antibodies (TRAbs) have been known to be involved in Graves' disease and primary hypothyroidism. We previously isolated and reconstituted immunoglobulin (Ig) genes of Epstein-Barr virus-transformed B cell clones producing monoclonal TRAbs obtained from Graves' patients. In the present study, we performed a similar experiment using a B cell clone, 32A-5, derived from a patient with primary hypothyroidism. The variable region genes of Ig heavy (H) and light (L) chains were isolated and sequenced from the 32A-5 clone. A significant number of somatic mutations were found in variable regions of H and L chain gene segments. Each pair of H and L chain cDNAs was ligated into an expression vector for IgG1 production and stably introduced into myeloma cells. The transfectants were injected ip into BALB/c mice to yield ample volume of the antibody for following applications. Interactions of recombinant 32A-5 with Graves' sera with varying thyroid-stimulating antibody (TSAb) activities were studied. The recombinant antibody tended to suppress TSAb activities in 10 of 15 Graves' sera, in which four were significantly inhibited. In summary, this is the first study to analyze human monoclonal TSH-stimulation blocking antibodies (TSBAb) at the molecular level. Use of human recombinant monoclonal TSBAb may be an analytical tool for molecular-basis etiology and an alternative therapeutic path for Graves' disease.

Retrovirus-specific random mutagenesis by a nucleoside 5'-triphosphate analogue, PTP

In a retrovirus replication model system, which consists of in vitro transcription and reverse transcription cycles, 6-(beta-D-ribofuranosyl)-3,4- dihydro-8H-pyrimido[4,5-c][1,2]oxazin-7-one-5'-triphosphate (PTP) induced highly efficient random mutations and this was due to the ambiguous incorporation of PTP by RNA polymerases. The types of mutations were mainly C-to-U or U-to-C transition mutations and the frequency was about 4 x 10(-2)/nucleotide during four cycles of the replication. Since a high mutation rate is harmful to species, PTP may be new candidate for anti-retroviral drugs. N4-aminoCTP and N4-hydroxyCTP were also incorporated ambiguously by RNA polymerase. These compounds may have a potential to induce mutation by the same mechanism as PTP.

Reverse transcriptional mutagenesis induced by ribonucleoside triphosphate analogue, PTP and its availability for anti-HIV-1 therapy

The bicyclic pyrimidine analogue, 3,4-dihydro-6H,8H-pyrimido[4,5-c][1,2]oxazin-7-one (P) can base pair with both A and G. The riboside 5'-triphsophate of P (PTP) efficiently induces mutation during in vitro transcription and reverse transcription cycles using a phage promoter. In the present study, we have constructed an in vitro transcription system promoted by the human immunodeficiency virus type 1 (HIV-1) 5'-long terminal repeat (LTR) using HeLa nuclear extract supplemented with HIV-1 Tat protein. Using this system, the effects of mutagenic ribonucleotide analogues were studied.

The phytochemical lindleyin, isolated from Rhei rhizoma, mediates hormonal effects through estrogen receptors

Some plant compounds or herb mixtures are popular alternatives to conventional therapies and contain organic compounds that bind to some nuclear receptors, such as the estrogen receptor (ER), to exert various biological effects. We studied the effect of various herbal extracts on ERalpha and ERbeta isoforms. One herbal extract, Rhei rhizoma (rhubarb), acts as an agonist to both ERalpha and ERbeta. The phytochemical lindleyin, a major component of rhubarb, might contribute to this estrogenic activity through ERalpha and ERbeta. 4-Hydroxytamoxifen, an ER antagonist, completely reversed the estrogenic activity of lindleyin. Lindleyin binds to ERalpha in vitro, as demonstrated using a fluorescent polarization assay. The in vivo effect of rhubarb extract was studied using a vitellogenin assay system in the freshwater fish, Japanese medaka (Oryzias latipes). There were marked increases in serum vitellogenin levels in male medaka exposed to rhubarb extract. We conclude that lindleyin, a component of some herbal medicines, is a novel phytoestrogen and might trigger many of the biological responses evoked by the physiological estrogens.

Drug-induced neutropenia associated with anti-neutrophil cytoplasmic antibodies (ANCA): possible involvement of complement in granulocyte cytotoxicity

Although antineutrophil antibodies are thought to be involved in drug-induced neutropenia, neither the precise mechanisms nor the particular antigens on the neutrophil surface have yet been clarified. Recently, we examined a patient with Graves' disease who developed antineutrophil cytoplasmic antibodies (ANCA) after propylthiouracil treatment and exhibited neutropenia. Because several target antigens of ANCA are expressed on the surface of neutrophils, it was suggested that ANCA might contribute to neutropenia. The patient's serum bound specifically to neutrophils and HL-60 cells differentiated into granulocytes, and lysed the HL-60 cells via a complement-mediated mechanism. Furthermore, two representative ANCA antigens, proteinase 3 and myeloperoxidase, significantly inhibited both the binding and cytotoxicity of the serum. Finally, tumour necrosis factor-alpha, which is known to up-regulate cell surface expression of several ANCA antigens, enhanced both the binding and cytotoxicity of the serum. These findings suggest that ANCA induced by propylthiouracil contributed to leucopenia through a complement-mediated mechanism.

Dentocraniofacial morphology of 12 Japanese subjects with unilateral cleft lip and palate with a severe Class III malocclusion: a cephalometric study at the pretreatment stage of surgical orthodontic treatment

OBJECTIVE

The present study clarifies the dentocraniofacial morphology of patients with cleft lip and palate (CLP) with severe Class III malocclusion prior to surgical orthodontic treatment.

METHODS

The sample was 12 Japanese male subjects with repaired complete unilateral CLP (surgical CLP group; 21.2 +/- 1.92 years in mean age). Two sets of patients without CLP Class III malocclusion, consisting of 19 male subjects treated by surgical orthodontic treatment (surgical Class III group; 23.4 +/- 6.35 years in mean age) and 14 male subjects treated by nonsurgical orthodontic treatment (nonsurgical Class III group; 18.7 +/- 3.49 years in mean age) were used as controls. Analyses were performed using lateral and posteroanterior (P-A) cephalograms.

RESULTS

(1) The surgical CLP group showed significantly smaller values for overjet, SNA angle, and inclination of the maxillary incisor as compared with those of the surgical and nonsurgical Class III controls. The values of SNB, mandibular effective length, and ramus height in the surgical CLP group were significantly smaller than those of the surgical Class III group but were similar to those of the nonsurgical Class III group. (2) The mandible and the upper and lower dental arches deviated laterally toward the cleft side. The displacement of the mandible was correlated with that of the maxilla. These results show that CLP patients who required surgical orthodontic treatment had a characteristic dentocraniofacial morphology, compared to controls without CLP with Class III malocclusion.

Development of artificial seed crystal for crystallization of calcium phosphate

An artifical seed crystal material consisting of calcium silicate hydrate (5CaO x 6SiO2 x 5H2O : tobermorite crystals) applicable for phosphorus removal by crystallization was developed. Card-house shaped tobermorite crystals were developed on the seed material where orthophosphate crystallized as a calcium phosphate. The seed material can be manufactured by mixing siliceous and calcareous raw materials, pelletizing and subsequent autoclaving. Laboratory experiments were conducted to apply the new developed seed crystal material in the phosphorus recovery from sludge sidestreams of a wastewater treatment plant. In this crystallization process, the performance the carbon dioxide degassingprocess usually carried out when applying crystallization was not necessary, the hydroxyapatite was able to crystallize at a pH of 8.0 to 8.5 without precipitation of calcium carbonates. In the treatment of a sidestream with orthophosphate concentrations of 50 mgl(-1) and COD concentrations between 200 to 400 mgl(-1), phosphorus removal efficiencies ranging from 75 to 85% were observed. The seed crystal material was collected after the laboratory experiments and the chemical estimation and the germination test for agricultural reuse were performed. As a result, it was shown that the hydroxyapatite precipitated on the seed material had a 100% fusibility to soil and had characteristics to be a good nutrient source as a fertilizer for plants.

A low dose of ghrelin stimulates growth hormone (GH) release synergistically with GH-releasing hormone in humans

The synergistic relationship between GH-releasing secretagogue (GHS) and GH-releasing hormone (GHRH) with respect to GH secretion is well known. In the present study, we report a similar relationship between GHRH and ghrelin, a recently identified endogenous ligand for the GHS receptor. In normal male adults, various doses of ghrelin were intravenously administered alone or together with 1.0 microg/kg GHRH. At small doses of 0.08 and 0.2 microg/kg ghrelin, combined administration of the two peptides significantly stimulated GH release in a synergistic manner; the mean GH response values of the two peptide combinations were more than the summed mean GH response values of each peptide alone (P < 0.05). In addition, at 1.0 microg/kg ghrelin, the tendency of the synergistic effect was observed, although the comparison was not statistically significant probably due to a submaximal dose ceiling effect. No synergistic effects with respect to ACTH or prolactin secretion were observed. In conclusion, the synergistic interaction between ghrelin and GHRH was clearly shown and might be useful for a provocation test to diagnose GH deficiency.

Substantial production of ghrelin by a human medullary thyroid carcinoma cell line

Ghrelin, an endogenous ligand for the GH secretagogue receptor, is a novel acylated peptide produced in the gastrointestinal endocrine cells as well as neuroendocrine cells in the hypothalamus. The Ser(3) residue of ghrelin is modified by n-octanoic acid, a modification necessary for hormonal activity. Human medullary thyroid carcinoma is known to produce a variety of gastrointestinal and neuroendocrine peptides. In the present study we investigated ghrelin production in the thyroid gland, especially in human medullary thyroid carcinoma. PCR amplification demonstrated prepro-ghrelin gene transcripts in normal human thyroid tissue and two medullary thyroid carcinoma cell lines (human TT cells and rat 6-23 cells), but not in a rat thyroid follicular cell line. TT cells showed the expression of prepro-ghrelin mRNA of about 0.6 kb by Northern blot analysis. Furthermore, production of ghrelin in TT cells was demonstrated by RIA and immunocytochemistry. Accumulation of des-n-octanoyl ghrelin in the cultured medium of the cells was confirmed. Finally, human medullary thyroid carcinoma surgical specimens showed significantly higher des-n-octanoyl ghrelin contents than normal thyroid tissues. In conclusion, we revealed that ghrelin was produced by the human thyroid parafollicular carcinoma cell line, TT cells. These findings suggest that ghrelin is produced in the thyroid C cells as well as in medullary thyroid carcinoma and may provide opportunities to investigate its physiological role in the thyroid gland.

Characterization of the secretable ectodomain of thyrotropin receptor produced by the recombinant baculovirus system

Thyrotropin receptor (TSHR) is a member of the glycoprotein hormone receptor family and an autoantigen of Graves' disease. Various attempts have been made to obtain a large amount of soluble ectodomain of TSHR in insect or mammalian cells, but most of them failed to secrete the overexpressed ectodomain. In the present study, we observed that about one-third of the ectodomain protein (sTSHR-gp), in which the signal peptide of TSHR was replaced by the baculovirus-encoded glycoprotein 67-signal peptide, was secreted into the culture medium and the remainder stayed within cells in the recombinant baculovirus system. Microsequencing the N-terminal of the purified protein confirmed that the baculovirus signal peptide was cleaved at the expected site. Carbohydrate studies using several glycosidases and lectins revealed that the secreted form of the ectodomain had biantennary carbohydrate, whereas the non-secreted form had high-mannose. Moreover, the secreted form of sTSHR-gp exhibited high-affinity ligand binding, whereas the non-secreted form did not show any significant ligand binding. Regarding the interactions of TSHR ectodomains with anti-TSHR antibodies, both the secreted and non-secreted forms of sTSHR-gp, almost completely neutralized the stimulatory and inhibitory anti-TSHR antibody activities. In conclusion, we succeeded in secreting the ectodomain of TSHR into culture medium, which was capable of binding to TSH and neutralizing anti-TSHR antibody activities.

Apoptosis of periodontal ligament cells induced by mechanical stress during tooth movement

The mechanical force generated during tooth movement creates compressed and cell-free areas in the periodontal membrane. The way in which periodontal ligament cells disappear at the compressed area during tooth movement remains unclear. In the present study we examined whether periodontal ligament cells undergo apoptosis by mechanical stress during tooth movement using the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end-labelling method (TUNEL). TUNEL-positive stainings of periodontal ligament cells began to appear at the compressed areas 12 h after tooth movement, and the number of those cells reached maximum at 24 h after tooth movement. Thereafter TUNEL-positive cells disappeared at 48 h, and direct and undermining bone resorption began at the same area 72 h after tooth movement. These results showed that compressed periodontal ligament cells were eliminated by apoptosis in the early phase of tooth movement.

A low dose of ghrelin stimulates growth hormone (GH) release synergistically with GH-releasing hormone in humans

The synergistic relationship between GH-releasing secretagogue (GHS) and GH-releasing hormone (GHRH) with respect to GH secretion is well known. In the present study, we report a similar relationship between GHRH and ghrelin, a recently identified endogenous ligand for the GHS receptor. In normal male adults, various doses of ghrelin were intravenously administered alone or together with 1.0 microg/kg GHRH. At small doses of 0.08 and 0.2 microg/kg ghrelin, combined administration of the two peptides significantly stimulated GH release in a synergistic manner; the mean GH response values of the two peptide combinations were more than the summed mean GH response values of each peptide alone (P < 0.05). In addition, at 1.0 microg/kg ghrelin, the tendency of the synergistic effect was observed, although the comparison was not statistically significant probably due to a submaximal dose ceiling effect. No synergistic effects with respect to ACTH or prolactin secretion were observed. In conclusion, the synergistic interaction between ghrelin and GHRH was clearly shown and might be useful for a provocation test to diagnose GH deficiency.

MC3T3-E1-conditioned medium-induced mineralization by clonal rat dental pulp cells

Dental pulp is thought to participate in supplementary mineralization, such as reparative dentin and pulp stones, but no direct proof of this has been reported. To study this process at a molecular level, we investigated the matrix mineralization of dental pulp using a clonal cell line (RPC-C2A) derived from rat incisor dental pulp. Mineralized nodules in extracellular matrix were formed by RPC-C2A cells cultured in the presence of conditioned medium (CM) from confluent osteoblastic MC3T3-E1 cells. These nodules were stained by the von Kossa method and with alizarin red S and quantified by the measurement of acid-soluble calcium deposition. This CM was most effective when collected 3-6 days after confluency and added at 50% to the culture medium. The CM-treated RPC-C2A cells showed high alkaline phosphatase activity, a high mRNA level of osteocalcin and decreases in the mRNA levels of osteopontin and osteonectin, but undetectable levels of mRNA of dentin sialophosphoprotein by Northern blot analyses. A pan-specific anti-transforming growth factor (TGF)-beta antibody and a soluble form of receptor for bone morphogenetic protein (BMP)-2/-4 did not neutralize the CM-induced mineralization. These results suggest that some soluble factor(s) other than TGF-beta or BMP-2/-4 in the CM from MC3T3-E1 cells cause differentiation of RPC-C2A cells to osteoblast-like cells.

Degradation and fracture of Ni-Ti superelastic wire in an oral cavity

Superelastic Ni-Ti wire is widely used in orthodontic clinics, but delayed fracture in the oral cavity has been observed. Because hydrogen embrittlement is known to cause damage to Ti alloy systems, orthodontic wires were charged with hydrogen using an electro-chemical system in saline. Tensile tests were carried out, and fracture surfaces were observed after hydrogen charging. The strength of the Co-Cr alloy and stainless steel used in orthodontic treatment, was not affected by the hydrogen charging. However, Ni-Ti wire showed significant decreases in strength. The critical stress of martensite transformation was increased with increasing hydrogen charging, and the alloy was embrittled. The fractured surface of the alloys with severe hydrogen charging exhibited dimple patterns similar to those in the alloys from patients. In view of the galvanic current in the mouth, the fracture of the Ni-Ti alloys might be attributed to the degradation of the mechanical properties due to hydrogen absorption.

Highly efficient random mutagenesis in transcription-reverse-transcription cycles by a hydrogen bond ambivalent nucleoside 5'-triphosphate analogue: potential candidates for a selective anti-retroviral therapy

The nucleoside P can base pair with both A and G. We evaluated the mutation frequency induced by the 5'-triphospbate of the ribonucleoside P (PTP) in an in vitro retroviral replication model. After 4 cycles of replication in the presence of PTP, the mutation frequency was raised to 3.8 x 10(-2) per nucleotide and C-to-U and U-to-C mutations were dominantly observed. These results suggest that ambivalent NTP analogues, like PTP, could induce mutations beyond the error threshold of retroviruses.

Novel mutations in ABCA1 gene in Japanese patients with Tangier disease and familial high density lipoprotein deficiency with coronary heart disease

Mutations in the ATP-binding cassette transporter 1 (ABCA1) gene have been recently identified as the molecular defect in Tangier disease (TD) and familial high density lipoprotein deficiency (FHA). We here report novel mutations in the ABCA1 gene in two sisters from a Japanese family with TD who have been described previously (S. Ohtaki, H. Nakagawa, N. Kida, H. Nakamura, K. Tsuda, S. Yokoyama, T. Yamamura, S. Tajima, A. Yamamoto, Atherosclerosis 49 (1983)) and a family with FHA. Both probands of TD and FHA developed coronary heart disease. Sequence analysis of the ABCA1 gene from the patients with TD revealed a homozygous G to A transition at nucleotide 3805 of the cDNA resulting in the substitution of Asp 1229 with Asn in exon 27, and a C to T at nucleotide 6181 resulting in the substitution of Arg 2021 with Trp in exon 47. Sequence analysis of the ABCA1 gene from the FHA patient revealed a homozygous 4 bp CGCC deletion from nucleotide 3787 to 3790 resulting in premature termination by frameshift at codon 1224. These mutations were confirmed by restriction digestion analysis, and were not found in 141 control subjects. Our findings indicate that mutations in the ABCA1 gene are associated with TD as well as FHA.

[A case of vaginal implantation of transitional cell carcinoma of the bladder]

An 82-year-old female presented with asymptomatic gross hematuria in June 1997. Urethrocystoscopy revealed a multiple papillary tumor of the bladder and posterior urethra. Histology of the punch biopsy specimens of the tumor revealed transitional cell carcinoma (TCC), grade 2 (G2). CT scan showed no distant metastasis and extravesical invasion. The patient was treated by intravesical instillation of adriamycin (ADM), drip infusion of low dose cisplatin (CDDP) and irradiation of the bladder. As the treatment caused a significant tumor shrinkage, transurethral resection of the tumor was performed. Histologically, the tumor revealed no invasion to the muscular layer of the bladder. In April 1998 she noticed genital bleeding, and a multiple papillary tumor was found on the vaginal wall. Histology of punch biopsy specimens of the vaginal tumor showed non-invasive TCC, G2. MRI and specimens of all layer needle biopsy showed no infiltration outside the bladder wall and the vaginal wall. Irradiation of the cavity of the vagina and uterus was made under the diagnosis of superficial vaginal TCC. We assume that vaginal implantation via irrigating fluid or urine has occurred.

Phosphorylation of cofilin by LIM-kinase is necessary for semaphorin 3A-induced growth cone collapse

Semaphorin 3A is a chemorepulsive axonal guidance molecule that depolymerizes the actin cytoskeleton and collapses growth cones of dorsal root ganglia neurons. Here we investigate the role of LIM-kinase 1, which phosphorylates an actin-depolymerizing protein, cofilin, in semaphorin 3A-induced growth cone collapse. Semaphorin 3A induced phosphorylation and dephosphorylation of cofilin at growth cones sequentially. A synthetic cell-permeable peptide containing a cofilin phosphorylation site inhibited LIM-kinase in vitro and in vivo, and essentially suppressed semaphorin 3A-induced growth cone collapse. A dominant-negative LIM kinase, which could not be activated by PAK or ROCK, suppressed the collapsing activity of semaphorin 3A. Phosphorylation of cofilin by LIM-kinase may be a critical signaling event in growth cone collapse by semaphorin 3A.