Acellular Extrinsic Fiber Cementum Is Invariably Present in the Superficial Layer of Apical Cementum in Mouse Molar

The cementum is a highly mineralized tissue that covers the tooth root. The regional differences among the types of cementum, especially in the extrinsic fibers that contribute to tooth support, remain controversial. Therefore, this study used second harmonic generation imaging in conjunction with automated collagen extraction and image analysis algorithms to facilitate the quantitative examination of the fiber characteristics and the changes occurring in these fibers over time. Acellular extrinsic fiber cementum (AEFC) was invariably observed in the superficial layer of the apical cementum in mouse molars, indicating that this region of the cementum plays a crucial role in supporting the tooth. The apical AEFC exhibited continuity and fiber characteristics comparable with the cervical AEFC, suggesting a common cellular origin for their formation. The cellular intrinsic fiber cementum present in the inner layer of the apical cementum showed consistent growth in the apical direction without layering. This study highlights the dynamic nature of the cementum in mouse molars and underscores the requirement for re-examining its structure and roles. The findings of the present study elucidate the morphophysiological features of cementum and have broader implications for the maintenance of periodontal tissue health.

Effect of Sparc knockout on the extracellular matrix of mouse periodontal ligament cells

The periodontal ligament (PDL) is a critical component in maintaining tooth stability. It is composed of cells and an extracellular matrix (ECM), each with unique roles in tissue function and homeostasis. Secreted protein acidic and rich in cysteine (SPARC), a calcium-binding matricellular glycoprotein, plays a crucial role in regulating ECM assembly and turnover, alongside facilitating cellular-ECM interactions. In the present study, mass spectrometry-based proteomics was used to assess the impacts of Sparc-knockout (KO) on PDL-derived cells. Results demonstrated that Sparc-KO significantly reduces ECM production and alters its composition with increased levels of type I collagen. Despite this increase in Sparc-KO, type I collagen was not likely to be effectively integrated into the fibrils due to collagen cross-linking impairment. Furthermore, the pathway and process enrichment analyses suggested that SPARC plays a protective role against ECM degradation by antagonistically interacting with cell-surface collagen receptors. These findings provide detailed insights into the multifaceted role of SPARC in ECM organization, including its impact on ECM production, collagen regulation, and interactions with various cellular compartments. A better understanding of these complex mechanisms is crucial for comprehending the causes of periodontal disease and tissue regeneration, where precise control of ECM organization is necessary.

Multiomics analysis of cultured mouse periodontal ligament cell-derived extracellular matrix

A comprehensive understanding of the extracellular matrix (ECM) is essential for developing biomimetic ECM scaffolds for tissue regeneration. As the periodontal ligament cell (PDLC)-derived ECM has shown potential for periodontal tissue regeneration, it is vital to gain a deeper understanding of its comprehensive profile. Although the PDLC-derived ECM exhibits extracellular environment similar to that of periodontal ligament (PDL) tissue, details of its molecular composition are lacking. Thus, using a multiomics approach, we systematically analyzed cultured mouse PDLC-derived ECM and compared it to mouse PDL tissue as a reference. Proteomic analysis revealed that, compared to PDL tissue, the cultured PDLC-derived ECM had a lower proportion of fibrillar collagens with increased levels of glycoprotein, corresponding to an immature ECM status. The gene expression signature was maintained in cultured PDLCs and was similar to that in cells from PDL tissues, with additional characteristics representative of naturally occurring progenitor cells. A combination of proteomic and transcriptomic analyses revealed that the cultured mouse PDLC-derived ECM has multiple advantages in tissue regeneration, providing an extracellular environment that closely mimics the environment in the native PDL tissue. These findings provide valuable insights for understanding PDLC-derived ECM and should contribute to the development of biomimetic ECM scaffolds for reliable periodontal tissue regeneration.

Extracellular Matrix-Oriented Proteomic Analysis of Periodontal Ligament Under Mechanical Stress

The periodontal ligament (PDL) is a specialized connective tissue that provides structural support to the tooth and is crucial for oral functions. The mechanical properties of the PDL are mainly derived from the tissue-specific composition and structural characteristics of the extracellular matrix (ECM). The ECM also plays key roles in determining cell fate in the cellular microenvironment thus crucial in the PDL tissue homeostasis. In the present study, we determined the comprehensive ECM profile of mouse molar PDL using laser microdissection and mass spectrometry-based proteomic analysis with ECM-oriented data curation. Additionally, we evaluated changes in the ECM proteome under mechanical loading using a mouse orthodontic tooth movement (OTM) model and analyzed potential regulatory networks using a bioinformatics approach. Proteomic changes were evaluated in reference to the novel second harmonic generation (SHG)-based fiber characterization. Our ECM-oriented proteomics approach succeeded in illustrating the comprehensive ECM profile of the mouse molar PDL. We revealed the presence of type II collagen in PDL, possibly associated with the load-bearing function upon occlusal force. Mechanical loading induced unique architectural changes in collagen fibers along with dynamic compositional changes in the matrisome profile, particularly involving ECM glycoproteins and matrisome-associated proteins. We identified several unique matrisome proteins which responded to the different modes of mechanical loading in PDL. Notably, the proportion of type VI collagen significantly increased at the mesial side, contributing to collagen fibrogenesis. On the other hand, type XII collagen increased at the PDL-cementum boundary of the distal side. Furthermore, a multifaceted bioinformatics approach illustrated the potential molecular cues, including PDGF signaling, that maintain ECM homeostasis under mechanical loading. Our findings provide fundamental insights into the molecular network underlying ECM homeostasis in PDL, which is vital for clinical diagnosis and development of biomimetic tissue-regeneration strategies.

In vivo cell proliferation analysis and cell-tracing reveal the global cellular dynamics of periodontal ligament cells under mechanical-loading

Periodontal ligament (PDL) is a uniquely differentiated tissue that anchors the tooth to the alveolar bone socket and plays key roles in oral function. PDL cells can respond rapidly to mechanical stimuli, resulting in accelerated tissue remodeling. Cell proliferation is an initial event in tissue remodeling and participates in maintaining the cell supply; therefore, analyzing cell-proliferative activity might provide a comprehensive view of cellular dynamics at the tissue level. In this study, we investigated proliferating cells in mouse molar PDL during orthodontic tooth movement (OTM)-induced tissue remodeling. Our results demonstrated that the mechanical stimuli evoked a dynamic change in the proliferative-cell profile at the entire PDL. Additionally, cell-tracing analysis revealed that the proliferated cells underwent further division and subsequently contributed to tissue remodeling. Moreover, OTM-induced proliferating cells expressed various molecular markers that most likely arise from a wide range of cell types, indicating the lineage plasticity of PDL cells in vivo. Although further studies are required, these findings partially elucidated the global views of the cell trajectory in mouse molar PDL under mechanical-loading conditions, which is vital for understanding the cellular dynamics of the PDL and beneficial for dental treatment in humans.

Pathological changes of renal tubular dysplasia in Japanese black cattle

Pathological studies were conducted on 91 Japanese Black cattle with a hereditary disease which induced growth retardation, long hooves and renal failure. In calves one to two months old, no gross abnormalities were observed in the kidneys, but microscopical examinations revealed immature epithelia which were arranged irregularly and not attached to the basement membranes in some proximal tubules. In animals three to 36 months old, the kidneys had shrunk perceptibly and had grey-white radial streaks; microscopically they showed severe interstitial fibrosis with round-cell infiltration in the outer zone of the medulla and cortex, and reductions in the numbers of glomeruli and tubules. In the fibrotic areas there were immature epithelia with an irregular arrangement, and the basement membrane of the tubules was thickened. It was concluded that renal tubular dysplasia was the primary lesion of the disease, and that interstitial fibrosis and reductions in the numbers of nephrons were secondary lesions.

The Senami Wrist Supporter for patients with rheumatoid arthritis

Abstract One of the wrist orthoses, the Senami Wrist Supporter (SWS), was applied to 203 rheumatoid wrists in 112 patients who had persistent wrist pain and restricted forearm rotation due to synovitis and instability at the distal radioulnar joint (DRUJ). The study was performed by sending out a questionnaire to the patients about the use of the SWS at home, and examining grip strength and forearm rotation with and without the use of the SWS. The average age of the patients was 61 years, and the average follow-up period was 18 months. The rate of compliance of wearing the SWS at home was 73% on average. It was higher in wrists of Larsen-Dale-Eek (LDE) grades 0, I, and II (normal, slight, and definite early abnormality) than in those of grades III, and IV (medium and severe destructive abnormality). Decreased pain was noted in 52% of the wrists at the time of applying the SWS. The SWS was not used in 10% of the wrists because of remission of pain at follow-up. Grip strength increased significantly (P < 0.01) and so did forearm rotation (P < 0.05) by the stabilizing effect of the SWS on the unstable DRUJ. The use of the SWS was confirmed to be an efficient measure to treat painful rheumatoid wrists with early stages of disease at the DRUJ.

[Management of permanent pacemaker implantation in elderly patients]

We evaluated the clinical characteristics of 297 consecutive patients who underwent permanent pacemaker implantation. Their mean age was 67 +/- 13 years; those at least 75 years old accounted for 30.9%. The underlying diseases were sick sinus syndrome in 36.7%, atrioventricular block in 58.9%, and atrial fibrillation with bradycardia in 4.4%. There was no association between age and either the voltage threshold or the R wave amplitude at the time of implantation. When pacemakers were exchanged, only patients aged 75 years or less had voltage thresholds that were higher and lead resistances that were lower than those measured at the time of initial implantation. No clear differences were observed in the R wave amplitude, regardless of age. With careful long-term management, permanent pacemaker implantation and follow-up clinical care can be safe, even in aged patients.

Adrenal tumor producing 11-deoxycorticosterone, 18-hydroxy-11-deoxycorticosterone and aldosterone

A case of adrenal tumor producing 11-deoxycorticosterone, 18-hydroxy-11-deoxycorticosterone and aldosterone is reported. A 55-year-old woman had hypertension, hypokalemia, low plasma renin activity and an adrenal tumor. The plasma level of aldosterone was normal, and the levels of 11-deoxycorticosterone and 18-hydroxy-11-deoxycorticosterone were extremely high. After the tumor removal, the plasma level of aldosterone decreased and plasma levels of 11-deoxycorticosterone and 18-hydroxy-11-deoxycorticosterone were normalized. The tumor was benign adenoma and the production of steroid hormones was under control of adrenocorticotropic hormone. The enzyme activity of 21-hydroxylation in the tumor was elevated and that of 11 beta-hydroxylation was decreased compared with the adjacent tissue.

Application of in situ hybridization with a novel phenytoin-labeled probe to conventional formalin-fixed, paraffin-embedded tissue sections

Non-isotopic in situ hybridization with a novel phenytoin (PHE)-labeled probe was developed. The mixture of cloned cytomegalovirus (CMV) DNA fragments was labeled by random primer technique using PHE-11(spacer)-dUTP, instead of dTTP. The tissue sections were treated with 0.2 N HCl and with proteinase K (1 microgram/ml), and then heated at 70 degrees C in the presence of 50 or 75% formamide. The sections were hybridized with PHE-labeled probe at 37 degrees C overnight. The hybridization signal was visualized by alkaline phosphatase-5-bromo-4-chloro-3-indolyl phosphate (BCIP)/4-nitroblue tetazolium (NBT) system. Strong hybridization signals were detected in sections of the small intestine and the placenta, even when denatured in the presence of 50% formamide. In the case of small intestine, CMV DNA was also detected in the endothelial cells of the mucosa where apparent infected cell was not observed histologically. In the sections of the submaxillary gland, the lung, the adrenal gland and the ovary, hybridization signal was not detected when denatured in the presence of 50% formamide, but detected after denaturation with 75% formamide. Thus, in situ hybridization with the novel PHE-labeled probe is applicable to conventional formalin-fixed, paraffin-embedded tissue sections.

Role of carboxyl tail of the rat angiotensin II type 1A receptor in agonist-induced internalization of the receptor

Binding of angiotensin II (Ang II) to its receptor type 1A (AT1A) is known to trigger its internalization. We studied the role of cytosolic segments of AT1A in the internalization, and obtained results indicating a functional role of the cytosolic carboxyl terminal tail of AT1A in the internalization. Deletion of 50 amino acids from the carboxyl terminus abolished the receptor internalization. Deletion mutants lacking 13 and 32 amino acid residues in the carboxyl terminal cytosolic region were internalized to the same extent as wild type AT1A; however, internalization of a mutant lacking the last 42 residues was partially suppressed. Thus, residues 310 through 327 were shown to be essential for the internalization. We propose that a short domain in the cytoplasmic tail (residues 310 to 327) may play a dominant role in the agonist-induced receptor internalization of AT1A. Our results also suggest that the molecular determinants of the AT1A receptor involved in receptor internalization are distinct from those participating in the desensitization process.

The genomic organization of human angiotensin II type 1 receptor

As a step toward the elucidation of human Ang II type 1 receptor gene expression, the genomic organization of the human AT1 receptor was investigated. Comparison of the genomic DNA and cDNA sequences revealed that it consists of at least five exons. The length of the AT1 receptor gene is greater than 55 kb, and the size of the exons ranges from 59 to 2,014 base pairs. Four of the exons encoded 5'-untranslated sequences. Multiple transcription initiation sites were observed by primer extension experiment. The promoter function was examined by using luciferase as a report gene in transfected human vascular smooth muscle cells.

Improvement of simultaneous detection of antibodies to Gag and envelope antigens of human T-lymphotropic virus type I by western immunoblot assay

To determine seropositivity for human T-lymphotropic virus type I (HTLV-I), we attempted to improve the detection system that uses antibody to HTLV-I Env in Western immunoblotting (WB) by adding an envelope glycoprotein (gp46) purified from the culture fluid of HTLV-I-producing cells by immunoaffinity chromatography and gel chromatography. In this WB, 177 of 179 serum samples showing seropositivity in an indirect immunofluorescence assay showed positive reactions to the gp46 envelope antigen as well as to p19, p24, and p53 Gag antigens. The remaining two samples showed negative reactions to p24. False-positive results were not found for 533 indirect immunofluorescence assay-negative serum samples, although one band to p19 or p24 was observed in 46 of the 533 samples. These 46 samples did not react to p53 and gp46, suggesting that these samples belonged to the indeterminate group in accordance with the criteria proposed by the World Health Organization. Therefore, this improved WB can be used for the confirmation of seropositivity.

Improvement of gelatin particle agglutination test for detection of anti-HTLV-I antibody

Partial modifications of antigen components were made to improve the gelatin particle agglutination (PA) test for the detection of antibodies against human T cell leukemia virus type-I. Envelope glycoproteins prepared by lentil lectin affinity chromatography were further added to the purified viral antigens to be coated on the gelatin particles. Comparative studies with a conventional PA test kit (Serodia ATLA) and indirect immunofluorescence assay showed that the specificity and sensitivity of the new PA test were increased and that abnormal agglutination such as the prozone phenomenon was abolished by this improvement.

Systemic lupus erythematosus of childhood onset: correlation between T cells expressing early and late activation antigens and disease activity

Correlation between T cell phenotypes, especially activated T cells expressing early (EA1) and late (HLA-DR) activation antigens and clinical features were investigated in 22 patients with systemic lupus erythematosus (SLE) of childhood onset. Percentages of T cells expressing EA1 and HLA-DR in 22 patients with SLE were significantly higher than those in controls. Comparison of T cell phenotypes between patients with active and inactive SLE showed that eight patients with active disease had significantly increased percentages of HLA-DR positive T cells than 14 with inactive disease (P less than 0.01). Serial examinations showed that the percentages of HLA-DR positive T cells were decreased after therapy in seven with active non-renal or active non-renal and renal diseases but not in one with only active renal disease. A possible significance of T cells expressing EA1 and HLA-DR in the management of patients with SLE is discussed.

Lymphocyte subpopulations of peripheral blood in tsutsugamushi disease

We examined lymphocyte subpopulations in the peripheral blood and serum concentrations of immunoglobulin (Ig) in 8 patients with tsutsugamushi disease. In 7 of the 8 cases, there was a 4-fold or greater increase in IgG and IgM antibody titers between the initial and convalescent serum specimens. In one case, there was no increase, but IgM antibodies were detected with diagnostically significant antibody titers. The percentages of CD8- and CD2-positive lymphocytes measured before treatment were found to be significantly higher than during the recovery stage of patients with tsutsugamushi disease. The CD4/CD8 ratio in the peripheral blood calculated before treatment was significantly lower than that during the recovery stage. Serum concentrations of IgG and IgM in patients during the recovery stage were significantly higher than pretreatment levels, respectively.

Plasma noradrenaline and its deaminated metabolites in essential hypertension and pheochromocytoma

Dihydroxyphenylglycol (DOPEG) is a metabolite of noradrenaline (NA) in the sympathetic nerve endings, and dihydroxymandelic acid (DOMA) is one in the extraneuronal tissues. The measurement of plasma DOPEG and DOMA were evaluated with NA as one of the clinical indices of sympathetic nerve activity. These were measured in essential hypertension and also applied for diagnosis of pheochromocytoma. Plasma DOPEG levels were correlated with NA. Plasma NA and DOPEG were decreased after oral administration of clonidine (150 micrograms) and plasma DOPEG levels were slowly increased after standing. Therefore, plasma DOPEG seemed to be useful as one of the rather stable indices of the sympathetic nerve activity. Plasma NA and DOPEG levels in WHO stage I essential hypertension were higher than those in normotensive controls. Observed normal plasma noradrenaline and DOPEG levels in stage II reflect the normalized sympathetic tone in this stage. The elevation of plasma NA and DOMA levels in stage III seemed to be at least partly explained by renal function disturbance. In patients with pheochromocytoma, despite of the marked elevation of plasma NA and DOMA, plasma DOPEG showed only three-fold elevation and the ratio DOPEG/NA was reduced. The simultaneous measurement of plasma NA, DOPEG and DOMA is useful to evaluate sympathetic nerve activity in essential hypertension and to differentiate pheochromocytoma in hypertension.

Seroepidemiology of human T-lymphotropic retrovirus type I (HTLV-I) in residents of Niigata Prefecture, Japan. Comparative studies by indirect immunofluorescence microscopy and enzyme-linked immunosorbent assay

A large sample of carriers of human T-lymphotropic retrovirus type I (HTLV-I) in Niigata Prefecture was examined for the detection of natural antibodies to HTLV-I-related antigens in sera using both indirect immunofluorescence microscopy (IFM) and enzyme-linked immunosorbent assay (ELISA). The present findings are based on multiple surveys, using each assay technique at least twice. Although Niigata Prefecture has been considered a non-endemic region for HTLV-I, Sado Island has been proven by this study to be a relatively endemic pocket within this non-endemic area. Seropositivity was highest in residents of Sado Island; 97/1, 117 (8.7%) by IFM and 33/1,061 (3.1%) by ELISA; followed by Niigata City, 18/650 (2.8%) by IFM and 16/638 (2.5%) by ELISA; and lowest in the remaining areas, 57/2,631 (2.2%) by IFM and 20/2,551 (0.8%) by ELISA. Seropositivity was demonstrated in 172/4,398 (3.9%) by IFM and 69/4,250 (1.6%) by ELISA in Niigata Prefecture taken as a whole. In general, the incidence of seropositive residents increased gradually with age. The sex difference was not significant. The serum samples tested were categorized into 4 groups; (1) IFM and ELISA both positive, (2) IFM positive but ELISA negative, (3) IFM negative but ELISA positive, and (4) IFM and ELISA both negative. By absorption tests, IFM and ELISA seemed to recognize different specific antibodies in sera; IFM recognized antibodies to HTLV-I-related cellular antigens in addition to HTLV-I viral antigens, but ELISA recognized antibodies to HTLV-I viral antigens alone. Thus, IFM detected a broader spectrum of antigens, resulting in recognition of more positive sera than those detected by ELISA.

Acting mechanisms of Lentinan in human--II. Enhancement of non-specific cell-mediated cytotoxicity as an interferon inducer

The immunopotentiator "Lentinan" augmented the cell-mediated cytotoxicity in humans. (a) The activation of killer T cells by the mixed lymphocyte culture was accelerated only when responder cells were mixed with both a suboptimum number of stimulator cells and Lentinan. (b) The interferon level in the peripheral blood circulation of cancer patients was elevated in 12 h following Lentinan administration, and natural killer activity of peripheral mononuclear cells was enhanced in 48 h. These data indicate that Lentinan favorably affects the host mechanisms of man.