Biomedical subjects

Y Miki

Publications and source records attributed to Y Miki.

At least 181 records · Page 10Linked to original sources

PubMed1990

Mechanism of inactivation of myeloperoxidase by propylthiouracil.

The mechanism of inactivation of myeloperoxidase purified from rat bone marrow by propylthiouracil (PTU) was studied. PTU inhibited not only the peroxidase activity but also the chlorinating activity of myeloperoxidase in a concentration dependent manner. When myeloperoxidase was treated with PTU and hydrogen peroxide (5 microM), inactivation of the enzyme was still observed after the excess reagents were removed by a column of Sephadex G-25. The treatment of the enzyme with PTU in the absence of hydrogen peroxide caused a slight inhibition of the enzyme activity. In addition, [14C]PTU became bound to myeloperoxidase in the presence of hydrogen peroxide. Difference spectrum of myeloperoxidase incubated with the small (0.1 mM) and large (2 mM) amounts of hydrogen peroxide revealed the formation of compounds II and III, respectively. Difference spectrum of myeloperoxidase treated with PTU in the presence of a low concentration of hydrogen peroxide (5 microM) was similar to that of compound II. Therefore, these results indicate that PTU inactivates myeloperoxidase through binding to the enzyme and the conversion to a compound II-like form in the presence of hydrogen peroxide.

Animals↗

PubMed1990

[CT-guided biopsy of thoracic mass lesions followed by fast stain technique].

We performed CT-guided needle biopsy of 92 thoracic mass lesions using a Rotex-II screw needle. Fast stain technique was performed for an immediate evaluation of the specimen in the last 39 procedures. The overall accuracy of malignancy was 93.2%, and the correct histological typing was obtained in 82.8% of malignancy proven at surgery or autopsy. The method enabled histopathological diagnosis of thoracic lesions, which could not obtained by other diagnostic modalities including fiberoptic bronchoscopy or fluoroscopy-guided biopsy. The true positive rate increased up 10.2% to 91.3% by introducing fast stain technique. A close cooperation between radiologists and cytopathologists was essential for performing this CT-guided biopsy procedure followed by fast stain technique.

Adenocarcinoma↗

PubMed1990

Molecular nature of chromosome 5q loss in colorectal tumors and desmoids from patients with familial adenomatous polyposis.

Familial adenomatous polyposis (FAP), which includes familial polyposis coli (FPC) and the Gardner syndrome (GS), is a genetically determined premalignant disease of the colon inherited by a locus (APC) mapping within 5q15-q22. To elucidate the role of 5q loss in FAP tumorigenesis, we analysed 51 colorectal tumors and seven desmoids from 19 cases of FPC and five GS patients, as well as 15 sporadic colon cancers. RFLP analysis revealed a high incidence of allelic deletion in hereditary colon cancers as well as in sporadic colon cancers with a peak at the APC locus. APC loss resulted primarily from interstitial deletion or mitotic recombination. Combined tumor and pedigree analysis in a GS family revealed loss of normal 5q alleles in three tumors, including a desmoid tumor, which suggests the involvement of hemizygosity or homozygosity of the defective APC gene in colon carcinogenesis and, possibly, in extracolonic neoplasms associated with FAP.

Adenomatous Polyposis Coli↗

PubMed1990

Change of genetic expression by physical compression forces.

Despite intense investigation of transmembrane signalling mediated by lymphocyte surface molecules, the subcellular mechanisms responsible for these phenomena remain poorly understood (Kishimoto, T. et al., 1983). In the present study, an answer for the mechanism is demonstrated by using human B blastoid cell line (CESS) which has IgG and Interleukin 6 (IL-6) receptors on the cell surface and produces IgG in response to IL-6 without any requirement for proliferation (Muraguchi, A. et al., 1981).

Animals↗

PubMed1990

The innermost cell layer of the outer root sheath is positive with Ki-67.

The expression of a cell proliferation-associated human nuclear antigen was immunohistochemically studied in human anagen hair and hair follicles using the monoclonal antibody Ki-67. The reaction of Ki-67 in mature anagen hair follicles was observed in the hair matrix cells and outer root sheath (ORS) cells. Nuclear staining was seen in a small number of matrix cells and in some ORS cells; this finding corresponded to the thymidine or bromodeoxyuridine labeling studies previously reported. In addition, there were two different patterns of cytoplasmic staining in the ORS: strong staining of the innermost cells (IMC) and weaker staining of the other ORS cells in the isthmus. Ki-67 reactivity of the IMC layer was observed at each stage of anagen and was regularly seen from the upper bulb to the isthmus. Ki-67 is a commercially available antibody that detects cycling cells. However, the IMCs in anagen hair follicles showed cytoplasmic labeling by Ki-67 from the matrix cells in the upper bulb to the distal portion of the isthmus.

Adolescent↗

PubMed1990

The relationship between solar keratoses and squamous cell carcinomas among Japanese.

Between 1976 and 1988, 135 patients with solar keratosis (SK) and 53 patients with squamous cell carcinoma (SCC) on the sun-exposed skin, but without apparent preceding diseases such as burn scars, chronic radiodermatitis, chronic arsenic poisoning, or xeroderma pigmentosum, were encountered. Sixteen of the SCC patients also had SK on other areas of sun-exposed skin. There were 31 SCC patients also showing SK (SK-SCC) and 22 SCC not showing SK (DN-SCC) within the same histologic sections. The mean ages of the patients with SK-SCC and with DN-SCC were similar. Metastases to regional lymph nodes were observed in 5 SK-SCC patients, of whom 3 died of the disease, and in 5 DN-SCC patients, of whom 4 died of the disease. The five-year post-operative survival rates were 70% in SK-SCC and 74% in DN-SCC; the ten-year post-operative survival rates were 70% in SK-SCC and 44% in DN-SCC.

Aged↗

PubMed1990

Subclass characteristics of IgG autoantibodies in bullous pemphigoid and pemphigus.

Immunoglobulin (Ig) G subclasses in anti-basement membrane zone (BMZ) autoantibodies found in the sera of bullous pemphigoid (BP) and in anti-intercellular substance (ICS) autoantibodies of pemphigus were investigated using immunofluorescent (IF) staining. In BP, IgG4, IgG1, and IgG2 were detected in 13, 5 and 6 of 15 patients, respectively; IgG3 was not detected. In pemphigus, IgG4 was detected in all of 10 patients, IgG1 in 7, IgG2 in one, and IgG3 in one patient, respectively. In both BP and pemphigus, the most prominent subclass in intensity of IF staining was IgG4. Although one BP and one PV patient had only IgG4 autoantibodies, C3 deposition was detected. The quantification of IgG subclasses in the sera of the patients was performed by enzyme-linked immunosorbent assays (ELISA). Serum levels of IgG4 in both BP and pemphigus were elevated approximately 3-fold over those in normal controls; those of whole IgG and IgG1-3 were not significantly elevated. Using direct IF staining, the deposition of C3 at the BMZ and at the ICS was demonstrated in 9 of 10 BP and in 3 of 8 pemphigus patients, respectively. The prominent IgG subclasses of anti-BMZ and anti-ICS antibody were IgG4, a noncomplement-fixing antibody, suggesting that the deposition of C3 in the lesional skin occurred via the alternative pathway, or that small amounts of IgG1-3 subclass autoantibodies activated the classical pathway.

Autoantibodies↗

PubMed1990

Characterization of homologous restriction factor (HRF20) in human skin and leucocytes.

Homologous restriction factor with a molecular weight of 20 kD (HRF20) is a membrane protein that inhibits assembly of the membrane attack complex of homologous complement. Distribution of HRF20 in normal human skin was studied. The plasma membrane of keratinocytes was stained, and the intensity of the staining pattern was higher in the basal cell layer than in the granular layer. Endothelial cells of blood vessels in the dermis were also stained. The molecular weight of HRF20 on erythrocytes and epidermis is 16 kD, determined by Western blot analysis. Those of polymorphonuclear cells and lymphocytes appeared as two bands, a major band of 20 kD and a minor band of 16 kD. Susceptibility of HRF20 to phosphatidylinositol-specific phospholipase C (PIPLC) was examined. After PIPLC treatment of the sections, HRF20 was not detected on the epidermis and was very slightly expressed on the blood vessels. These results indicate that HRF20 attaches to keratinocytes and blood vessels via phosphatidylinositol, regulating the formation of membrane attack complexes of homologous complement on the cell membrane.

Blood Proteins↗

PubMed1990

HLA class II (DR, DQ) in Japanese patients with type 1 diabetes mellitus.

DNA restriction fragment length polymorphism (RFLP) typing of HLA-DR and DQ alleles of 60 Japanese type 1 (insulin dependent) diabetic patients and 115 controls was performed. RFLP typing of DRB1 showed increased frequency of DR9 and decreased frequencies of DR2 and DRW6 among patients compared to controls. In the RFLP typing of BamHI-digested DNA to DQ beta probe (BamHI-DQB1), the incidence of the 10.26 kb fragment, which represents either DQW4, DQW8 or DQW9, was markedly elevated in the patients, whereas the incidence of DQW6 was reduced. The predicted DR-DQ haplotype study revealed that DR4-DQW4 or DQW8, DRW8-DQW4 or DQW8 and DR9-DQW9 may contribute to susceptibility to type 1 diabetes. When serological typing of the 13 DRW8 patients was performed, all the 11 DRW8 patients carrying DQW4 or DQW8 (BamHI-10.26 kb) were positive for DQW3. These results indicated that the HLA-DQ locus may play an important role in the development of type 1 diabetes in the Japanese as well as other ethnic groups and that the DRW8-DQW8 haplotype may predispose to the disease in Japan.

Alleles↗

PubMed1990

Acantholytic variant of seborrheic keratosis.

From among 524 histologic specimens of seborrheic keratosis (SK), 29 showed acantholysis, not related to pemphigus, Darier's disease, actinic keratosis or acantholytic squamous cell carcinoma. Acantholysis was found in 24 (23.3%) of the irritated type of SK, almost exclusively in the squamous cell nests showing dyskeratosis and spongiosis between and around squamous eddies or horn cysts. Clinically, 65.5% of the lesions were located on the face and scalp, 20.7% on the trunk and 13.8% on the limbs. It was speculated that dyskeratotic, degenerative changes of the keratinocytes together with spongiosis were responsible for the acantholysis.

Acantholysis↗

PubMed1990

Isolation of a fibroblast attachment protein from cementum.

Cementum forms the interface through which soft connective tissue of the periodontium is attached to the root surface. The interactions between cementum and connective tissue are not completely understood and whether cementum influences periodontal connective tissue formation and regeneration is not clear. We have examined the effect of cementum components on the attachment of gingival fibroblasts. Cementum was harvested from healthy human and bovine teeth and extracted sequentially in 0.5 M CH3COOH, 4 M guanidine and bacterial collagenase. Fibroblast attachment was measured using 51Cr-labelled human gingival fibroblasts on tissue culture plates previously incubated with cementum components. Results showed that all three extracts mediated fibroblast attachment and attachment was dependent on concentration and incubation time. The attachment activity was not destroyed by digestion with bacterial collagenase or by antibodies to fibronectin and laminin. However, it was inhibited by a peptide containing the amino acid sequence RGD. By gel filtration or HPLC using a DEAE-cellulose column several proteins with attachment activity were fractionated. SDS-polyacrylamide gel electrophoresis revealed that HPLC fraction eluted by 0.2-0.3 M NaCl contained a protein with molecular weight 55 kDa as a major component. This protein was isolated and shown to promote fibroblast attachment, and optimal attachment occurred at a concentration of 2 micrograms/ml. We conclude that cementum contains substances capable of mediating fibroblast attachment and that these substances play an important role in periodontal connective tissue formation and regeneration by facilitating fibroblast attachment to root surfaces.

Amino Acid Sequence↗

PubMed1990

Clinical usefulness of urinary growth hormone measurement in short children.

Growth hormone (GH) levels in nocturnal urine were measured in 96 short children and 73 children of normal height in order to investigate whether urinary GH levels reflect spontaneous GH secretion and whether they might be used to screen short children for GH treatment. GH levels in 24-hour urine samples were significantly correlated with urinary albumin and beta 2-microglobulin levels in normal children, demonstrating an influence of renal function on urinary GH measurements. Nocturnal urinary GH levels showed significant positive correlations with mean serum GH levels during 3 hours of sleep (r = 0.26, p less than 0.05) and plasma insulin-like growth factor I (IGF-I) levels, reflecting physiological GH secretion. Urinary GH levels were significantly lower in the eight children with complete GH deficiency (3.1 +/- 2.3 ng/g creatinine) than in the normal children (13.8 +/- 11.2 ng/g creatinine). Urinary GH levels in three other groups of short children, partial GH deficiency (11.1 +/- 16.9 ng/g creatinine), impaired GH secretion during sleep (10.4 +/- 12.6 ng/g creatinine) and non-endocrine short stature (18.8 +/- 19.5 ng/g creatinine), were not significantly different from those in the normal children. However, when the cut-off point for defining GH insufficiency was set at 5 ng/g creatinine, 87.5% (21 out of 24) of the short children with low urinary GH levels were suitable subjects for GH treatment (i.e. had complete GH deficiency, partial GH deficiency or impaired GH secretion during sleep).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1990

Pituitary adenomas and normal pituitary tissue: enhancement patterns on gadopentetate-enhanced MR imaging.

A dynamic study of magnetic resonance (MR) imaging was used to obtain successive heavily T1-weighted coronal images (spin-echo [SE] 100/15 [repetition time msec/echo time msec]) of normal pituitary glands and pituitary adenoma immediately after patients were given an intravenous bolus injection of gadopentetate dimeglumine. The images were obtained every minute for 5-8 minutes at 1.5 T. Usual T1-weighted images (SE 600/15) were also obtained before and after the dynamic study was performed. The study group consisted of 18 patients, 10 with normal pituitary glands, and eight with pituitary adenoma. Normal pituitary glands showed maximum enhancement on the first or second image following the administration of gadopentetate dimeglumine, followed by gradual signal reduction through the later images, whereas pituitary adenomas reached a peak of enhancement later and showed slower signal reduction than normal pituitaries. The difference of enhancement patterns between the normal pituitary gland and the pituitary adenoma produced prominent image contrast on the first or second image after administration of gadopentetate dimeglumine, which improved the visualization of one microadenoma and four normal pituitary glands that had been displaced by large adenomas. Dynamic MR imaging is a useful diagnostic procedure not only for detection of microadenomas, but also for visualization of pituitary glands that have been displaced by large pituitary adenomas.

Adenoma↗

PubMed1990

A vegetating variety of pemphigus foliaceus.

A 77-year-old man was seen with florid, vegetating nodules in the umbilical, axillary and inguinal areas, scaly erythema in the trunk and fragile nails. Histologically, marked to moderate acanthosis and papillomatosis with intraepidermal abscesses composed of acantholytic cells, eosinophils and neutrophils were seen in the vegetating lesions which showed intercellular IgG deposit by the direct immunofluorescence technique. There were no circulating pemphigus antibodies. The lesions were successfully treated by topical corticosteroids. However, flaccid bullae with hypopyon showing subcorneal acantholysis and intercellular IgG deposits continued to develop. After 3 1/2 years, circulating pemphigus antibody of IgG2 subclass was demonstrated.

Acantholysis↗

PubMed1990

Synthesis and bioactivity of propranolol analogues with a rigid skeleton. I.

The synthesis of two kinds of propranolol analogues, A and B, with a rigid skeleton was investigated. The compounds were designed to help identify the conformation involved in beta-adrenergic receptor-propranolol interaction. The key intermediate, 2-hydroxy.2,3-dihydronaphtho[1,8-bc]pyran (5), was obtained starting from acenaphthenone (1). On sequential dehydration, hydroboration, and oxidation, 5 gave 2,3-dihydronaphtho[1,8-bc]pyran-3-one (8), which was converted to compound A. Compound 5 was also derived to 2-formyl-2,3-dihydronaphtho[1,8-bc]pyran (13) via the 2-vinyl compound (12). Condensation of nitromethane with 13 followed by reduction and alkylation produced the desired compound B. The beta-blocking activities of A and B were examined.

Adrenergic beta-Antagonists↗

PubMed1990

Bone marrow peroxidases of spontaneously hypertensive rats.

The activity of peroxidases and the level of myeloperoxidase in the bone marrow of spontaneously hypertensive rats (SHR) and stroke-prone SHR (SHR-SP) were determined in comparison with normotensive Wistar Kyoto rats (WKY). In the cetyltrimethylammonium bromide extract of bone marrow, the peroxidase activities using guaiacol or Kl as the electron donor of male and female WKY were different from those of SHR and SHR-SP. The peroxidase activity was also separately determined as myeloperoxidase and eosinophil peroxidase by the use of ion-exchange high pressure liquid chromatography. In males, SHR and SHR-SP contained a low activity of eosinophil peroxidase compared with WKY. Bone marrows of female SHR and SHR-SP contained a lower activity of myeloperoxidase, while SHR and SHR-SP possessed a higher activity of eosinophil peroxidase compared with WKY. No change of the level of myeloperoxidase in the bone marrow was observed among male animals. A significant decrease in the level of myeloperoxidase was observed in female SHR and SHR-SP. Therefore, these results indicate that the change in the activity of the peroxidases in the bone marrow is accompanied by the spontaneously hypertensive state.

Animals↗

PubMed1990

Change in the growth hormone (GH) response to GH-releasing factor (GRF) caused by exogenous GH in short children.

To determine whether exogenous GH induces feedback of GH release in children, growth hormone-releasing factor (GRP) tests were performed before and after 10-day GH administration. Sixteen non-obese short boys, aged 5-14 yr, with normal GH response to pharmacological tests were studied. Mean basal and peak serum GH levels in GRF tests before and after exogenous GH were not significantly different. The subjects were divided into two groups, A and B, according to the percent change in integrated areas under the GH curves in GRF tests (GH AUC) before and after 10-day GH administration. Group A consisted of 6 boys with decreased GH AUC and group B consisted of 10 boys with increased GH AUC. Mean peak GH in GRF tests and mean GH AUC were significantly higher before exogenous GH in group A than in group B. The boys in group A were all prepubertal, while 4 boys in group B had begun their early pubertal change. The mean age in group A (7.8 +/- 1.8 yr) was significantly lower than that of group B (11.9 +/- 2.4 yr). GH AUC before exogenous GH showed a significant correlation with the percent change in AUC (= -0.742, p less than 0.01). These data demonstrated that the exogenous GH suppressed the GH response to GRF in prepubertal children with good response to GRF before exogenous GH, while it exaggerated the GH response to GRF in older children with relatively poor response before GH.

Adolescent↗

PubMed1990

[MR imaging for lung cancer in evaluating local invasion; referring to CT and surgical-histological basis].

The diagnostic potentiality of MR imaging for lung cancer was researched in 17 patients in evaluating local invasions based on surgical-histological evidence. Comparative reviewing with CT was also performed. MR imaging appeared to have an ability unique to portray malignant invasions somewhere such as in the hili or apices. On the other hand, there were also some diagnostic limitations of MR imaging in delineating the localized invasive changes. On the way of working up lung cancer, CT still may stand at the first choice as a radiographic staging procedure which provides the more detailed anatomic-pathologic informations. We consider that MR imaging is mandatory when CT and/or other modalities could'not obtain efficient results.

Adenocarcinoma↗