Search PubMed⌕ Search

Biomedical subjects

S Murakami

Publications and source records attributed to S Murakami.

At least 541 records · Page 30Linked to original sources
PubMed1992

Radiographic investigation of idiopathic osteosclerosis of the jaws in Japanese dental outpatients.

Panoramic radiographs of 1203 Japanese patients were examined to detect idiopathic radiopaque foci of dense bone. One hundred seventeen patients (9.7%) exhibited 134 such lesions. The majority (97%) of the opacities were found in the mandible, especially in the mandibular first premolar to second molar region (85.4%). The lesion was most prevalent in the first three decades of life.

Chi-Square Distribution↗
PubMed1992

The clinicoradiologic predictability of perforations of the soft tissue of the temporomandibular joint.

One hundred thirty-one arthrographic examinations of temporomandibular joints were performed on 119 patients. The relationships between clinical symptoms, tomographic findings, and soft-tissue perforation were examined. Perforations of the articular disk or posterior attachment were revealed in 58 joints. Joints with crepitation showed a high frequency of perforation (20 of 22). Pain in the joint area and limitation of opening correlated to disk reduction. Perforations were observed in 12 of 21 joints with continuous pain. Osseous changes were detected in 89 joints. Joints with abnormal radiodensity (erosion, sclerosis) combined with abnormal shape (pocket erosion, osteophyte formation, deformity) showed a high frequency of perforation (41 of 45), which corresponded to 84% in this study. In those cases with osseous change or crepitation, positive predictive values of perforation were both 91%. These types of osseous change and their clinical significance might predict soft-tissue perforation with high accuracy before an arthrogram is performed.

Adolescent↗
PubMed1992

Inhibitory effect of tannic acid on gastric H+,K(+)-ATPase.

The effect of tannic acid on gastric H+,K(+)-ATPase was studied. Tannic acid dose-dependently inhibited pig gastric H+,K(+)-ATPase activity with an IC50 value of 2.9 x 10(-8) M. Tannic acid also inhibited K(+)-stimulated p-nitrophenyl phosphatase (K(+)-pNPPase) activity, which is found in gastric H+,K(+)-ATPase preparations, as well as H+,K(+)-ATPase activity, with an IC50 value of 4.1 x 10(-7) M. Kinetic studies showed that the inhibition of H+,K(+)-ATPase activity by tannic acid was competitive with respect to ATP and noncompetitive with respect to K+. These results show that tannic acid is a potent inhibitor of gastric H+,K(+)-ATPase; this may be related to its anti-secretory and anti-ulcerogenic effects.

Adenosine Triphosphatases↗
PubMed1992

A low copy number central sequence with strict symmetry and unusual chromatin structure in fission yeast centromere.

Fission yeast centromeres vary in size but are organized in a similar fashion. Each consists of two distinct domains, namely, the approximately 15-kilobase (kb) central region (cnt+imr), containing chromosome-specific low copy number sequences, and 20- to 100-kb outer surrounding sequences (otr) with highly repetitive motifs common to all centromeres. The central region consists of an inner asymmetric sequence flanked by inverted repeats that exhibit strict identity with each other. Nucleotide changes in the left repeat are always accompanied with the same changes in the right. The chromatin structure of the central region is unusual. A nucleosomal nuclease digestion pattern formed on unstable plasmids but not on stable chromosome. DNase I hypersensitive sites correlate with the location of tRNA genes in the central region. Autonomously replicating sequences are also present in the central region. The behavior of truncated minichromosomes suggested that the central region is essential, but not sufficient, to confer transmission stability. A portion of the outer repetitive region is also required. A larger outer region is necessary to ensure correct meiotic behavior. Fluorescence in situ hybridization identified individual cens. In the interphase, they cluster near the nuclear periphery. The central sequence (cnt+imr) may play a role in positioning individual chromosomes within the nucleus, whereas the outer regions (otr) may interact with each other to form the higher-order complex structure.

Base Sequence↗
PubMed1992

Shrinkage of tissue conditioners with time--effect of the particle size in powder and the EtOH content in liquid.

The dimensional change of tissue conditioners with time was measured until 4 weeks after mixing. Shrinkage of the materials was evaluated in relation to particle size in powder and the EtOH content in liquid. The dissolution of EtOH and plasticizer were also measured to investigate the relation to dimensional change. Shrinkage with time was recorded. The smaller the particle size in powder and the more EtOH in liquid, the greater the shrinkage rate. The smaller the particle size in the powder and the more EtOH contained in the liquid, the greater the dissolution of EtOH. The dissolution of BPBG was below 1/100 comparing that of EtOH and no difference was recognized by particle size and EtOH content. On the basis of these results it is suggested that the dissolution of EtOH is related to shrinkage of tissue conditioners with time and that the component particle size in the powder and EtOH content in the liquid have a significant influence on dissolution of EtOH associated with shrinkage.

Chromatography, Gas↗
PubMed1992

The unc-18 gene encodes a novel protein affecting the kinetics of acetylcholine metabolism in the nematode Caenorhabditis elegans.

Genes affecting acetylcholine (ACh) levels without influencing choline acetyltransferase activity have been identified in Caenorhabditis elegans. We have examined one such gene, unc-18. We isolated a transposon-insertion allele for unc-18 and used it to clone a genomic region containing the unc-18 locus. The unc-18 location within this region was determined by rescuing the unc-18 mutant phenotype in a germ-line transformation experiment and identifying transcripts affected by four independent unc-18 mutations. A single-sized poly(A)+ RNA was synthesized from the gene. Expression of the transcript appears to be stage specific: The transcript is found in abundance at the early larval stage but in decreased amounts at the fourth larval and the adult stages. These results show that the unc-18 gene plays a role in development as well as in the kinetics of ACh metabolism.

Acetylcholine↗
PubMed1992

Gastric H+, K(+)-ATPase inhibition by catechins.

Five catechins, (+)-catechin, (-)-epicatechin, (-)-epicatechin gallate, (-)-epigallocatechin and (-)-epigallocatechin gallate, inhibited gastric H+, K(+)-ATPase activity with IC50 values ranging from 1.7 x 10(-4) to 6.9 x 10(-8) M, with (-)-epigallocatechin gallate as the most potent inhibitor. The intensity of inhibitor activity paralleled the number of phenolic hydroxy groups in the molecule. The inhibition of the enzyme by (-)-epicatechin was competitive with respect to ATP and noncompetitive with respect to K+. These findings suggest that the anti-secretory and anti-ulcerogenic effects of catechins previously reported, are due to their inhibitory activity on gastric H+, K(+)-ATPase.

Adenosine Triphosphate↗
PubMed1992

Novel type of clonally involved cytoplasmic immunoglobulin-negative cells in multiple myeloma: flow cytometric study.

In order to identify myeloma cells and their precursor cells, we studied bone marrow samples from 39 patients with multiple myeloma, including 2 with plasma cell leukemia, using dual parameter cytometry of both DNA and cytoplasmic immunoglobulin (Cyt-Ig). Myeloma cells from 25 patients (64.1%) were aneuploid and those from the remaining 14 patients were diploid. In 25 patients with aneuploid myeloma, we found a small component of cells which had aneuploid DNA content without Cyt-Ig in addition to myeloma cells showing aneuploidy with Cyt-Ig. These aneuploid Cyt-Ig-negative cells were considered to be clonally involved because they were aneuploid, and detected predominantly in patients with stage III myeloma. This suggests that these cells may contribute to disease progression. The characteristics of these cells are described and the relationship between these cells and myeloma precursor cells is discussed.

Aneuploidy↗
PubMed1992

Effects of interleukin-3 and interleukin-6 on peripheral blood cells from multiple myeloma patients and their clinical significance.

The effects of interleukin-3 (IL-3) and interleukin-6 (IL-6) on nonadherent mononuclear cells (NMC) from the peripheral blood of 28 patients with multiple myeloma (MM), 3 patients with monoclonal gammopathy of undetermined significance (MGUS), and 3 normal controls were investigated. In 15 of 27 evaluable patients with MM, monoclonal-cytoplasmic-immunoglobulin (cIg)-positive plasma cells appeared from the T-cell-depleted NMC after 10 days of culture in the presence of IL-3 and IL-6. These changes were not observed in the T cell fraction of myeloma blood or in the T-cell-depleted NMC obtained from cases of MGUS or from normal controls. The percentage of cIg-positive plasmacytoid cells after 10 days of culture was significantly higher in the presence of both IL-3 and IL-6 than with each interleukin alone or the control medium. Furthermore, these changes were often observed in untreated patients. These findings suggest that myeloma precursor cells exist in the peripheral blood of MM patients, especially at diagnosis, and differentiate into cIg-positive cells in the presence of IL-3 and IL-6. This assay may be useful in discriminating the early stage of myeloma from MGUS.

Antigens, CD↗
PubMed1992

Changes on distribution of CD4+/CD45RA- and CD8+/CD11- cells in tumor-infiltrating lymphocytes of renal cell carcinoma associated with tumor progression.

To study the distribution of subsets of T cells in renal cell carcinoma, peripheral blood lymphocytes (PBL) and tumor-infiltrating lymphocytes (TIL) were analyzed in 43 untreated patients using two-color flow cytometry. An increase in the relative number of CD4+/CD45RA-, CD8+/CD11- and HLA-DR+/CD3+ cells was shown in TIL when compared with PBL. When the influence of various tumor factors on subsets of TIL was examined, a decrease in CD4, CD4+/CD45RA- and CD16+/CD57- cells and an increase in CD8+ and CD8+/CD11- cells was observed along with the aggravation of tumor stage and grade. In TIL of stage III/IV and grade III/IV disease, most patients showed an increase in CD8+/CD11- associated with a decrease in CD4+/CD45RA- cells, or the reverse, resulting in changes of the CD4+/CD45RA- to CD8+/CD11- ratio. The prognosis for these patients was poor, suggesting that changes in the ratio were a sign of the impairment of local immune status associated with disease progression.

Adult↗
PubMed1992

Experimental Tonsillophilus suis granuloma in rats and guinea pigs.

Rats and guinea pigs were experimentally infected by intradermal and intraperitoneal inoculation of T. suis. These animals were observed for pathologic changes at various stages. Macroscopic observation disclosed visible grayish white soft nodules at the injection site in those inoculated intradermally and many grayish white nodules in the peritoneum of those inoculated intraperitoneally. Histopathological examination revealed the presence of characteristic microbial elements in the centre of the lesions. Various stages of the lesions were recognized; the early stage being abscess, the advanced stage being pus-forming granuloma and the final stage being residual granuloma. The microbial elements were composed of spores, thalli and multilocular tubers. Clubs were formed around microbial elements in rats inoculated intradermally and in guinea pigs inoculated intraperitoneally. The characteristic T. suis lesions in pigs were reproduced by experimental infection of this organisms in rats and guinea pigs, and thus the pathogenicity of T. suis was confirmed.

Abscess↗
PubMed1992

Examination of antithyroid effects of smoking products in cultured thyroid follicles: only thiocyanate is a potent antithyroid agent.

We studied the antithyroid action of cigarette smoking products (nicotine, cotinine, and thiocyanate) in the physiological culture system of porcine thyroid follicles. Iodide uptake, iodine organification, de novo thyroid hormone formation, and iodide efflux were measured in the presence of 0-200 mumol/l nicotine, cotinine, or potassium thiocyanate. Nicotine and cotinine did not inhibit iodide transport or thyroid hormone formation. Thiocyanate concentrations equivalent to serum levels of smokers showed three independent antithyroid actions: (i) inhibition of iodide transport, (ii) inhibition of iodine organification, and (iii) increased iodide efflux. Inhibition of iodide transport by thiocyanate was competitive with iodide and independent of TSH concentration. Thiocyanate did not inhibit TSH mediated cAMP production or Na+K+ ATPase activity, a sodium pump for iodide transport. When 50 mumol/l thiocyanate was added 2 h after incubation with iodide or when 1 mumol/l thiocyanate was added from the beginning of incubation, iodine organification was inhibited without changing iodide transport. De novo thyroid hormone formation was clearly inhibited by 50 mumol/l thiocyanate. Thiocyanate increased iodide efflux although the degrees of iodide efflux by 10 mumol/l and 100 mumol/l thiocyanate did not differ significantly. In summary, thiocyanate, a product of smoking, has three independent antithyroid activities. The data of iodide transport kinetics suggest that thiocyanate can be an antithyroid agent particularly in iodine deficiency.

Animals↗
PubMed1992

What is vividness of imagery? Characteristics of vivid visual imagery.

Two experiments were conducted to examine the characteristics of vivid visual imagery. In Exps. 1 and 2, analysis showed that the subjects' drawings of their imagery indicated more visual features for the vivid imagers than for the non-vivid imagers and no difference in sketching time between the two groups. Image-construction time was shorter for the vivid imagers than for the nonvivid ones in Exp. 2, but no difference was found in Exp. 1. On the basis of these results, the mechanism underlying individual differences in vividness of imagery was discussed in relation to the model of imagery processes proposed by Kosslyn (1980) and his colleagues.

Color↗
PubMed1992

Inhibition of gastric H+, K(+)-ATPase by quercetin.

The effects of the naturally occurring flavonoid, quercetin, on gastric H+, K(+)-ATPase were investigated. Quercetin inhibited hog gastric H+, K(+)-ATPase and K(+)-stimulated p-nitrophenyl phosphatase (K(+)-pNPPase) activity in a dose dependent manner with IC50 values of 2.3 microM, and 6.0 microM respectively. The inhibition of H+, K(+)-ATPase by quercetin is competitive with ATP and is noncompetitive with K+. The steady-state phosphorylation level of the enzyme was also dose-dependently reduced by quercetin with an IC50 value of 4.5 microM. These results suggest that quercetin reduces the phosphorylated enzyme level by competition with ATP, and thereby inhibits the H+, K(+)-ATPase activity.

4-Nitrophenylphosphatase↗
PubMed1992

[Relationship between extent of bone metastases and effect of endocrine therapy evaluated with bone scintigraphy in stage D2 prostatic cancer].

Bone scintigraphy of metastatic lesion on 128 patients with prostatic cancer were classified according to the proposal by Soloway et al (Cancer, 61; 195-202, 1988). Since all patients received endocrine therapy, the response to therapy and survival were examined in relation to bone lesion. In extent of disease (EOD) 1, main metastatic lesions were located in the pelvis, lumbar spine, and with increasing number of EOD, metastases in the upper spine, rib, and skull appeared. Longer survival were noticed in EOD 1, followed by EOD 2 and EOD 3, and EOD 4 revealed the shortest survival. The survival of EOD 2 was similar to thus of EOD 3. However, when grades of tumor were considered, moderately differentiated cancer showed longer survival than poorly differentiated cancer in EOD 2 and EOD 3. The response as assessed by bone scintigraphy following 6-month therapy was well correlated with the number of EOD. When individual items for evaluation of response were examined, the results of local response of the prostate and values of PAP showed good correlation with survivals, however, that of bone lesions with bone scintigraphy failed to show such a correlation with prognosis. Therefore, it is concluded that the therapeutic evaluation of bone lesions with bone scintigraphy is difficult to interpret 6 months after initiation of treatment.

Adenocarcinoma↗
PubMed1992

[Incidence of renal cell carcinoma in Chiba Prefecture, Japan; ten years experience].

Many reports about the increase of renal cell carcinoma patients have been published in Japan recently, however, the real fluctuations in the total number of patients in relation to the change of population have not been reported yet. Most of the patients with renal cell carcinoma in the last 10 years were examined in Chiba prefecture, which has a population of about five million and 25 active urological offices. Histologically confirmed cases were investigated by sending questionnaire letters. The items were as follows; sex, age, address, occupation, family history, past history, symptoms, examination methods that first detected the tumor, operation date, tumor diameter and clinical stage. Twenty two offices returned answers and 560 cases who lived in Chiba were found to have renal cell carcinoma from 1980 to 1989. Yearly incidence rates per 100,000 persons demonstrated a significant increase from 0.32 to 2.07. Small, asymptomatic and low stage cancers have been increasing rapidly, however, the rate of metastatic disease has not shown any decrease. The main cause of rapid increase seems to be attributed to progress in diagnostic methods and increase of early detection, but the possibility of an increase in some carcinogenic factors can not be ruled out.

Adult↗