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Biomedical subjects

I Ishikawa

Publications and source records attributed to I Ishikawa.

At least 19 recordsLinked to original sources
PubMed1995

Reduced CD8+ peripheral blood T lymphocytes in rapidly progressive periodontitis.

The peripheral blood T-cell phenotype of patients with rapidly progressive periodontitis (RPP) was determined in order to investigate whether there were T-cell imbalances or not. Twenty patients aged 21-39 yr were selected for this study. Bone resorption and probing pocket depth were measured. All the patients had 10 or more teeth showing bone loss of 50% or more. As controls, 12 periodontally healthy, age-matched individuals were selected. Blood samples were obtained by venipuncture, and lymphocytes were isolated. Two-colour flow cytometric analysis was done with monoclonal antibodies against human CD4, CD8, and CD45RA antigens. The RPP patients were found to have significantly lower percentage of CD8+ T cells (Mann-Whitney's U-test, p < 0.01) and an increased CD4/CD8 ratio (Mann-Whitney's U-test, p < 0.01) compared with healthy individuals. On the other hand, there were no significant differences in the percentages of CD4+ T cells and CD4+ CD45RA+ T cells between RPP patients and healthy individuals. No correlations between the clinical findings and T-cell subsets were found. These findings suggest that imbalances of peripheral blood T lymphocytes, especially a tendency to decreased CD8 + T cells, exist in RPP patients, and that cellular immune responses mediated by CD8 + T cells may play a part in the pathogenesis of RPP.

Adult↗
PubMed1995

Current status of renal replacement therapy in Japan.

The study of the current status of renal replacement therapy in Japan is based on the analysis of data from the registry reports for regular dialysis therapy and kidney transplantation. The total number of patients receiving regular dialysis therapy was 123,926 at the end of 1992: 117,809 (95.1%) on hemodialysis and 6,117 (4.9%) on peritoneal dialysis. The primary diseases of newly accepted patients were chronic glomerulonephritis (42.2%), diabetic nephropathy (28.4%), nephrosclerosis (5.9%), polycystic kidney disease (2.7%), chronic pyelonephritis (1.6%), and others. The number of kidney transplant patients in Japan was 8,384 at the end of 1991: 6,154 (73.4%) received a living donor transplantation and 2,230 (26.9%) received a cadaver donor transplantation. Overall 5-year survival rates of dialysis patients were 60.4%: 69.7% for chronic glomerulonephritis, 41.7% for diabetic nephropathy, 39.6% for nephrosclerosis, 73.6% for diffuse polycystic kidney disease, and 66.6% for chronic pyelonephritis. The causes of death of dialysis patients were heart failure (31.1%), cerebrovascular accident (13.6%), infectious diseases (11.3%), malignancies (7.1%), cachexia/uremia (6.7%), myocardial infarction (5.8%), and others. The gross mortality rate of dialysis patients was increased in cases of less than 4 hours of the average length of each dialysis session, less than 4% and more than 9% of the average weight loss during each dialysis session, less than 1.0 of Kt/V, and less than 0.9 and more than 1.7 g/kg/d of protein catabolic rate. Overall 5-year patient and graft survival rates of kidney transplant patients since 1964 were 82.7% and 60.3%: 84.4% and 65.0% in living donor cases, and 77.4% and 46.2% in cadaver donor case, respectively. Those since 1983 were 90.1% and 68.2%: 91.3% and 72.6% in living donor cases, and 87.8% and 59.3%, respectively. Graft survival rates were superior in cases treated with combined steroid, cyclosporine and azathioprine or mizoribine, to those treated with other immuno-suppressive regimens, and they decreased as the number of HLA-A, -B and -DR increased.

Actuarial Analysis↗
PubMed1995

Multiple restriction fragment length polymorphism genotypes of Porphyromonas gingivalis in single periodontal pockets.

A total of 188 Porphyromonas gingivalis strains isolated from 13 periodontal pockets of 8 periodontitis patients were investigated by means of restriction fragment length polymorphism (RFLP) analysis using the fimA gene as a pobe. A total of 5 RFLP genotypes were identified, and over half of the isolates belonged to type I. Four of the 8 patients harbored only 1 RFLP genotype of P. gingivalis, and 1 patient harbored only 2 RFLP genotypes in different sites. On the other hand, in 3 other patients, multiple RFLP genotypes were found in single periodontal pockets. Further studies will be required to clarify whether multiple genotypes of P. gingivalis colonized a single periodontal pocket simultaneously or whether a mutation occurred in the fimbrilin gene locus of P. gingivalis.

Bacterial Proteins↗
PubMed1995

Effect of periodontal treatments on serum IgG antibody titers against periodontopathic bacteria.

Serum IgG antibody titers to 7 periodontopathic bacteria in periodontitis patients were measured at the 1st visit and after various periodontal treatments with clinically successful improvement, in order to evaluate what kind of factors are associated with changes of serum antibody titers. 20 patients (10 male and 10 female from 23 to 61 years old) with adult, rapidly progressive periodontitis were enrolled in this study. All patients received initial preparation and most of them also underwent surgical procedure. After the treatments, the mean probing pocket depths decreased from 3.72 mm to 1.56 mm. Serum samples were collected from patients at the initial and final examinations. Serum IgG antibody titers against sonicated antigens of Porphyromonas gingivalis FDC 381, Prevotella intermedia ATCC 25611, Prevotella loescheii ATCC 15930, Fusobacterium nucleatum subspecies nucleatum ATCC 25586, Actinobacillus actinomycetemcomitans FDC Y4, Eikenella corrodens FDC 1073 and Capnocytophaga ochracea # M 12 were determined by enzyme-linked immunosorbent assay. The mean antibody titers to P. gingivalis and P. intermedia decreased significantly after the treatment as compared to their pretreatment levels. The antibody titer to P. gingivalis, especially, decreased in all of the patients examined. A significant relationship was found between the decreased antibody titer to P. gingivalis and the number of teeth which received periodontal surgery, as well as treatment length, and the relationship between the decreased antibody titer to P. intermedia and the number of extracted teeth was also significant. These results suggest that the changes of serum IgG titers against P. gingivalis and P. intermedia are related to the suppression of such pathogens in subgingival plague.

Adult↗
PubMed1995

[Tumorigenesis of kidney tubule].

Renal cell carcinoma is derived from renal tubule, blastematous tubule or nephrogenic rest. Most common sporadic clear cell tumors have structural changes of the chromosomes, such as the cancer suppressor genes at 3p14, 3p21 or 3p25 (VHL gene). Cytogenetically, clear cell tumor (non papillary tumor) initially develops as a cancer, while papillary tumor progresses sequentially from atypical tubule to adenoma to carcinoma. Papillary tumors demonstrate numeric changes in the chromosomes. Renal cell carcinoma complicated with acquired renal cysts in dialysis patients tends to develop from papillary tumor. However, the exact mechanism inducing these genetic changes remains to be clarified.

Animals↗
PubMed1995

[Dynamic computed tomography (CT) in the rat kidney and application to acute renal failure models].

Renal dynamic CT scanning is suitable for determining the excretion of contrast medium in the cortex and medulla of the kidney, which is valuable for understanding the pathogenesis of disease processes in various conditions. This form of scanning would be convenient for use, if a method of application to the rat kidney were available. Therefore, we developed a method of applying renal dynamic CT to rats and evaluated the cortical and medullary curves, e.g., the corticomedullary junction time which is correlated to creatinine clearance, in various rat models of acute renal failure. The rat was placed in a 10 degrees oblique position and a bilateral hilar slice was obtained before and 5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100, 120, 140, 160 and 180 sec after administering 0.5 ml of contrast medium using Somatom DR. The width of the slice was 4 mm and the scan time was 3 sec. The corticomedullary junction time in normal rats was 23.0 +/- 10.5 sec, the peak value of the cortical curve was 286.3 +/- 76.7 Hounsfield Unit (HU) and the peak value of the medullary curve was 390.1 +/- 66.2 HU. Corticomedullary junction time after exposure of the kidney was prolonged compared to that of the unexposed kidney. In rats with acute renal failure, the excretion pattern of contrast medium was similar in both the glycerol- and HgCl2-induced acute renal failure models.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1995

[A familial case of ADPKD with intracranial aneurysms detected by MR angiography].

The management and screening of unruptured asymptomatic intracranial aneurysm (ICA) in patients with ADPKD and those with a family history of ICA remains a subject of considerable controversy. In recent years, it has been revealed that MRA (magnetic resonance angiography) can define the circle of Willis to allow detection of ICA as small as 3-4 mm. We report a case of a 63-year-old man with ADPKD and his family. No definite aneurysm was observed by angiography screening at 46 years of age, when he was referred for hemodialysis. For the past three years, his family history revealed that three relatives were suffering from subarachnoid hemorrhage at the ages of 32, 36 and 39 years, respectively, two of whom had ICA and one had arterio-venous malformation detected by angiography. Whether they had ADPKD was unknown, but two were suggestive of ADPKD. Therefore, our case underwent MRA as screening for ICA, which showed an ICA with a diameter of 5mm in the anterior communicating artery. The ICA was confirmed as being 6 mm in diameter by conventional angiography. His niece and her son, who had ADPKD, also underwent MRA, which showed a suspicious image of a 2 mm ICA in the latter case. These results suggest that prophylactic screening for ICA is important in an ICA clustering family. MRA is useful in screening for ICA and in the follow-up study on the natural course of ICA.

Adult↗
PubMed1995

Properties of alkaline phosphatase in the gingival crevicular fluid.

The isoenzymic properties of the alkaline phosphatase (ALP) of the gingival crevicular fluid (GCF) were investigated and compared with those in other cells, such as human polymorphonuclear leukocytes (PMNs), and human periodontal ligament cells (PDLs), and with those of three species of periodontopathic bacteria: Porphyromonas gingivalis 381 (P. gingivalis), Prevotella intermedia ATCC25611 (P. intermedia), and Capnocytophaga sputigena ATCC33123 (C. sputigena). The biochemical properties of the isoenzymes were analyzed by the following methods: enzyme assays, inhibition pattern using three chemical inhibitors, 4 to 20% gradient polyacrylamide gel electrophoresis, thermostability, immunological specificity, and phosphatidylinositol-specific phospholipase C (PI-PLC) treatment. The inhibition experiment showed that ALP of the PMNs and PDLs possessed almost the same enzymatic properties of tissue-nonspecific ALP (bone/liver/kidney; TNSALP), and the ALP of the three species of periodontopathic bacteria possessed specific properties that were different from those of TNSALP, intestinal, or placental ALP. The ALP of the GCF was only slightly susceptible to levamisole (1 mM), L-phenylalanine (20 mM), and SDS (1%). An electrophoresis thermostability test demonstrated that the enzyme activity of the GCF was separated into one or two bands. The main heat-labile slow band contained the phosphatidylinositol (PI)-moiety-anchored ALP and possessed immunological specificity against anti-bone type ALP. The minor fast band was heat stable and showed mobility similar to that in P. gingivalis. These results indicated that the ALP of the GCF consisted of several ALP isoenzyme types whose possible origins are considered to be derived from phosphatidylinositol (PI) anchored ALP and periodontopathic bacterial ALP.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Mouse homologue of C33 antigen (CD82), a member of the transmembrane 4 superfamily: complementary DNA, genomic structure, and expression.

C33 Ag (CD82) is a member of the transmembrane 4 superfamily (TM4SF) and an activation Ag of T-cells. Recent studies have shown that CD82 associates with CD4 or CD8 and delivers costimulatory signals for the TCR/CD3 pathway. We have isolated cDNA and genomic clones of mouse CD82. Mouse CD82 has 266 amino acid residues with 76% identity to human CD82. The mouse CD82 gene consists of nine exons and spans more than 20 kb of genomic DNA. The genomic organization of CD82 is quite similar to that of three other TM4SF members whose genomic structures were described, i.e., Tapa-1 (CD81), CD53, and CD63. By mapping the 5' end of CD82 transcripts, we found a single major transcription initiation site 144 bp upstream of the ATG initiation codon. We also determined the sequence of the 5' flanking region of CD82 gene for about 2 kb. The 5' flanking sequence has a housekeeping promoter with potential binding motifs for various transcriptional factors. Northern blot analysis showed quite variable expression of the CD82 gene among different organs. The highest expression was seen in the spleen and the kidney. The expression was low in skeletal muscle and hardly detectable in the heart. Northern blot analysis was also carried out for CD81, CD53, and CD63. The expression of the CD81 gene was ubiquitous and similar among different organs, while that of CD53 was seen only in the spleen. The expression of the CD63 gene was ubiquitous, with the highest expression in the kidney. These results together with the comparison of the structures of 5' flanking sequences of these genes indicate distinct regulations of gene expression for these four members of TM4SF.

Amino Acid Sequence↗
PubMed1994

Effects of cytokines and periodontopathic bacteria on the leukocyte function-associated antigen 1/intercellular adhesion molecule 1 pathway in gingival fibroblasts in adult periodontitis.

We investigated the effects of inflammatory cytokines and periodontopathic bacteria on expression of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1, and E-selectin (endothelial leukocyte adhesion molecule 1) in cultured human gingival fibroblasts (HGF). Cell surface ICAM-1 was upregulated on HGF under transcriptional control by exposure not only to interleukin-1 beta, tumor necrosis factor alpha, and gamma interferon but also to sonic extracts prepared from Porphyromonas gingivalis and Prevotella intermedia (nigrescens) and lipopolysaccharides from Escherichia coli. However, these stimuli induced only minimal expression of vascular cell adhesion molecule 1 and E-selectin on HGF. Binding assays using HGF and Molt 4, the human T-cell leukemia cell line, showed induced ICAM-1 to be functional, and the increased binding was blocked by a combination of monoclonal antibodies against ICAM-1 and leukocyte function-associated antigen 1. Furthermore, gingival tissues from adult periodontitis patients showed increased mRNA expression of ICAM-1 compared with that in tissues from normal healthy donors. In immunohistological analysis, we also observed in vivo that the expression of ICAM-1 on fibroblasts in adult periodontitis tissues was greater than that in normal gingiva. Thus, the overexpression of ICAM-1 on gingival fibroblasts induced by cytokines and periodontopathic bacteria is speculated to be deeply involved in the accumulation and retention of leukocyte function-associated antigen 1-bearing leukocytes in adult periodontitis lesions.

Adult↗
PubMed1994

In vitro studies on laser scaling of subgingival calculus with an erbium:YAG laser.

The effectiveness of a newly-developed Er:YAG laser with a fiber delivery system to remove subgingival calculus was examined in vitro. Fifty-three (53) periodontally-involved human extracted teeth with a band of subgingival calculus were used. Two experiments were conducted: in experiment 1, laser scaling was performed with water irrigation on a straight line and on a broad area, against the subgingival calculus at the energy levels of 10 to 120 mJ/pulse (3.5 to 42.4 J/cm2/pulse) and the pulse repetition rate of 10 pps. The morphological changes of the laser-scaled site were observed by SEM, and the efficiency of laser scaling was determined. In experiment 2, laser scaling was performed with and without water irrigation at 30 mJ/pulse and 10 pps. The morphological changes, the efficiencies, and temperature changes with and without water irrigation were compared. The pulsed Er:YAG laser used with water irrigation was able to remove the subgingival calculus from the tooth root effectively at the energy level of about 30 mJ/pulse (energy density: 10.6 J/cm2/pulse) and 10 pps, under in vitro conditions. Ablation of the tooth substance on laser scaling was generally observed within the cementum. There was little increase in temperature on the root surface during laser scaling. This study suggests the potential for the clinical application of the Er:YAG laser in subgingival scaling.

Analysis of Variance↗
PubMed1993

Distribution of Porphyromonas gingivalis in adult periodontitis patients.

Porphyromonas gingivalis (P. gingivalis) is considered to be a pathogenic factor in adult or rapidly progressive periodontitis. The purpose of this study was to evaluate the distribution of P. gingivalis in the dentition of adult periodontitis patients using a nonradioactive DNA probe, and to compare the presence of P. gingivalis with clinical parameters. Twelve adult periodontitis patients were examined. Subgingival plaque samples were taken from 4 sites of all the remaining teeth using a paper point. At the same time, probing depth and bleeding on probing (BOP) were also recorded. Plaque samples were investigated using a whole genomic DNA probe from P. gingivalis (ATCC 33277) modified with bisulfite. The detection, percentage and amounts of P. gingivalis present were statistically compared with probing depth and BOP in each patient. P. gingivalis was detected in all patients examined. The detection percentage was 35% of all sample sites. When the probing depth was over 4 mm or BOP was positive, the detection percentage of P. gingivalis significantly increased (P < 0.01). As more P. gingivalis was identified, the percentage of sites with deep probing depth or that were BOP positive increased significantly (P < 0.01). However, P. gingivalis was also detected in clinically healthy sites, and P. gingivalis negative sites with deep probing depth or that were BOP positive existed in the same patient. These results indicate that P. gingivalis play an important role, but is not the only microorganism responsible for adult periodontitis.

Adult↗
PubMed1993

[Immunohistochemical study in acquired cystic disease of the kidney--expression of vimentin, epidermal growth factor, epidermal growth factor receptor and c-erb B2 gene product].

Acquired cystic disease of the kidney (ACDK) reveals abnormal epithelial cell growth which suggests a cotinuum of cyst, adenoma and renal cell carcinoma (RCC). In the present study, we examined potential role of vimentin and growth factors for cyst growth and proliferation in 20 cases with ACDK by immunoperoxidase staining method. 1281 cysts with single-layered epithelia and 89 cysts with multi-layered epithelia (atypical cyst) were studied. Intermediated filament, vimentin was positive in staining in 41.6% of cysts with single-layered epithelia, in 73.1% of cyst with multi-layered epithelia and in 100% of adenomas and RCCs. Vimentin expression, therefore, may be considered as an indication of cellular differentiation among proliferating tubular or intracystic cells. In order to evaluate the growth and/or proliferative capabilities of cyst epithelia, epidermal growth factor (EGF), epidermal growth factor receptor (EGFR) and c-erb B2 gene product were determined in cyst epithelia, adenoma and adenocarcinoma. EGF showed positive staining in 49.1% of cyst with single-layered epithelia, in 68.4% of cyst with multi-layered epithelia, in 2 of 3 adenomas and in 5 of 8 RCCs. EGFR expression was observed in 61.7% of cyst with single-layered epithelia, in 94.7% of cyst with multi-layered epithelia, in 100% of adenomas and RCCs. Co-expression of EGF and EGFR was observed in 40.3% of cyst with single-layered epithelia and in 67.1% of cyst with multi-layered epithelia. C-erb B2 gene product was positive in 9.7% of cyst with single-layered epithelia, in 100% of cyst with multi-layered epithelia and in 3 of 7 RCCs. These findings indicate that the expression of vimentin and overexpression of these growth factors and receptors appear to be one of the mechanisms operating in potentiating the abnormal growth of cyst epithelia, including potential for oncogenesis of RCC.

Adolescent↗
PubMed1992

[Clinical and microbiological study of factors determining effective scaling and root planing].

The aim of the present study was to monitor longitudinally the clinical and microbiological parameters after root debridement in order to determine the factors affecting successful and unsuccessful results. Nine patients with moderate and severe periodontitis participated. Four sites of single root with over 5-mm periodontal pockets in each quadrant were selected. The oral hygiene was controlled in all patients, then root debridement was performed without anesthesia at the three sites of the quadrants every two weeks during eight weeks. The clinical parameters consisted of plaque index, gingival index, probing depth, clinical attachment level, bleeding on probing, tooth mobility and the value of gingival crevicular fluid (GCF). The microbiological parameters such as percentages of cocci, motile rods, non-motile rods and spirochetes and the number of microorganisms were examined and the percentages of black pigmented Bacteroides (BPB) and Actinobacillus actinomycetemcomitans as well as the number of anaerobic colonies were counted. The results demonstrated that a reduction in the probing depth was observed in all sites except four. The successful sites clinically showed a decrease of the probing depth and GCF value and, microbiologically, reduced percentages of the spirochetes and BPB. The results indicated that the decrease of the probing depth and GCF under 50 Periotoron units in coincidence with the bacterial reduction can be used to determine the successful response of root debridement.

Adult↗
PubMed1992

Cataract in renal transplantation recipients with combination ciclosporin treatment.

Post surgical cataracts induced by corticosteroids as immunosuppressive agents were investigated in recipients undergoing triple therapy with ciclosporin and the results were compared with those who had therapy without ciclosporin administration. The subjects of the triple therapy group were 54 cases with a mean age of 31.7 years. The mean observation period was 25 months. The incidence of posterior subcapsular cataract was 77.8%. 7.9% of them developed progressed cataract. Early cataractous changes were noticed within one post-operative year in half of the cases. 3 out of 22 cases that were followed up over three years showed progressed cataractous changes. The total doses of methylprednisolone during the period of the first post-transplant year in recipients with Grades I or II and over Grade III were 7.7 +/- 1.9g and 9.8 +/- 3.6g, respectively. They were significantly higher than those in the conventional therapy group. However, a 2 to 3 g reduction in the total dose of steroids during the first year had no influence on cataract occurrence.

Adolescent↗