Biomedical subjects

K Miyake

Publications and source records attributed to K Miyake.

At least 19 recordsLinked to original sources

PubMed1992

Expression of VLA-4 on thymocytes. Maturation stage-associated transition and its correlation with their capacity to adhere to thymic stromal cells.

The present study investigates the expression of VLA-4 on thymocytes at various stages of maturation and their capacity to adhere to thymic stromal cells. Whole thymocytes were stained with anti-CD4 and anti-CD8, as well as anti-VLA-4 antibodies. Flow microfluorometric analyses revealed that a) most of CD4-8- (double negative DN) and CD4-8intermediate thymocyte populations expressed large amounts of VLA-4, b) the levels of VLA-4 were considerably and markedly reduced on CD4+8+ (double positive DP) and single positive (SP) (CD4+8- or CD4-8+) populations, respectively. This contrasted with an increase in the levels of LFA-1 along with thymocyte maturation. DN, DP, and SP subsets were isolated and examined for their capacity to express VLA-4 and to adhere to fibronectin (FN) molecules as well as thymic stromal cells expressing FN. DN, DP, and SP subsets were confirmed to express the respective high, low, and very low levels of VLA-4, respectively. Approximately 70% of DN thymocytes became bound to FN-precoated culture plates, whereas 30 to 40% of DP and only 10 to 20% of SP cells adhered to FN. Similar patterns of adhesion were observed between these thymocyte subsets and thymic stromal monolayers. The binding of the DN subset to FN-plates or thymic stromal monolayers was inhibited only marginally by the RGDS peptide, but was efficiently inhibited by V10 peptide (cell-binding sequence that is located in the V region on FN and reacts with the VLA-4 integrin) or anti-VLA-4 antibody. Anti-VLA-4 antibody plus RGDS peptide strongly inhibited DN cell binding to FN-coated plates and thymic stromal monolayers. These results indicate that i) VLA-4 expressed on DN thymocytes functions as an important integrin for interacting with thymic stromal cells; ii) the expression level of this integrin decreases with the progress of thymocyte maturation, and iii) most of the mature thymocytes (SP) are rendered less adhesive to thymic stromal cells by reducing the level of VLA-4 expression.

Animals↗

PubMed1992

Highly restricted expression of a stromal cell determinant in mouse bone marrow in vivo.

B lymphocyte precursor cells in mouse bone marrow develop in close association with stromal cells which provide essential growth signals. To identify molecules that may normally play a role in this interaction we have examined the in vivo binding of a new monoclonal antibody (mAb) (KMI6) that recognizes a determinant on a bone marrow stromal cell line (BMS2) in vitro. Flow cytometric and radioautographic evaluations revealed that the antigen recognized by KMI6 is represented on the surface of an extremely small number of cells in bone marrow cell suspensions from adult mice. An apparent molecular mass of 110 kD was obtained by surface labeling of a stromal cell clone and immunoprecipitation. Purified mAb KMI6 labeled with 125I was then given intravenously to young C3H/HeJ mice. Unbound mAb was washed out by cardiac perfusion and femoral bone marrow was examined by light and electron microscope radioautography. KMI6 labeling was heavy on the plasma membrane of many stromal cells, especially those located towards the outer subosteal region. The KMI6-labeled stromal cells were usually associated with cells of lymphoid morphology which they often completely surrounded. The labeling was restricted to areas of stromal cell plasma membranes in contact with lymphoid cells. The lymphoid cells themselves, as well as macrophages and other hemopoietic cells, failed to bind mAb KMI6 significantly. Stromal cells in bone marrow depleted of hemopoietic cells by gamma-irradiation (9,5 Gy) bound mAb KMI6 at reduced intensity. The results demonstrate that the KMI6 determinant, a 110-kD protein, is expressed on bone marrow stromal cells in vivo. Its restriction to areas of interaction with lymphoid cells suggests a role in forming microenvironmental niches of B lymphopoiesis. The surface membrane of individual stromal cells may thus be functionally polarized towards interacting B cell precursors and other hemopoietic cells.

Animals↗

PubMed1992

Cloning of murine and rat vascular cell adhesion molecule-1.

Vascular cell adhesion molecule-1 (VCAM1) is a member of the immunoglobulin (Ig) superfamily which interacts with the integrin very late antigen 4 (VLA4). We have cloned the cDNAs for both murine and rat VCAM1 from endotoxin-treated lung libraries. Both sequences encode proteins with seven extracellular Ig-like domains, which show 75.9% and 76.9% identity, respectively, with human VCAM1. Both murine and human cell lines show VLA4-dependent binding to COS cells transiently expressing murine and rat VCAM1. Two mAbs, M-K/1 and M-K/2, which recognize an antigen on murine bone marrow stromal cell lines, bind to murine VCAM1 expressed in COS cells and block VCAM1-dependent adhesion, confirming that these mAbs recognize murine VCAM1.

Amino Acid Sequence↗

PubMed1992

Requirements for hyaluronic acid binding by CD44: a role for the cytoplasmic domain and activation by antibody.

The CD44-negative T lymphoma AKR1 (CD44.2 genotype) was transfected with a CD44.1 cDNA. The intact cDNA conferred on the transfected cells the ability to bind hyaluronic acid (HA) both from solution and immobilized on culture plates. It also conferred a CD44-dependent and hyaluronidase-sensitive increase in adhesion to a lymph node endothelial cell line. A mutant cDNA which codes for a CD44 molecule lacking most of the cytoplasmic domain of CD44 was also transfected into AKR1, and cell sorting was used to select transfectants expressing levels of cell surface CD44 expression comparable with the line transfected with the wild-type CD44 cDNA. The cells transfected with the mutant construct bound fluoresceinated HA from solution very poorly, but did adhere to immobilized HA, though less well than cells transfected with the wild-type construct. This result indicates that the cytoplasmic domain of CD44 is necessary for binding of HA from solution but is not required for binding to immobilized HA, although it may contribute to adhesion following ligand recognition. A monoclonal antibody (mAb), IRAWB 14, which reacts with CD44 on all CD44+ cells dramatically induced HA binding by some CD44+ cell lines that did not constitutively bind HA. The transfectant expressing a CD44 molecule with a truncated cytoplasmic domain could be induced by this antibody to bind fluoresceinated-HA from solution. Splenic T cells did not bind fluoresceinated HA constitutively. In the presence of the IRAWB 14 mAb, virtually all CD44+ splenic T cells bound HA. Induction was immediate and occurred equally well at room temperature and at 4 degrees C, indicating that the new HA-binding activity was due to preexistent CD44 molecules. These results are compatible with an antibody-induced activation of CD44 by either a conformational change in the CD44 molecule or a change in the distribution of CD44 molecules on the cell surface.

Animals↗

PubMed1992

Pharmacokinetic analysis of maprotiline and its demethylated metabolite in serum and brain of rats after acute and chronic oral administration of maprotiline.

Compartmental model analysis by simultaneous curve fitting was used to ascertain the pharmacokinetic relationship between maprotiline (MAP) and its demethylated metabolite desmethylmaprotiline (DMAP) in the serum and brain of rats after single or multiple oral administrations of MAP. The extent of bioavailability and the fraction metabolized to DMAP after acute oral administration were 0.202 and 0.065, respectively, indicating first-pass metabolism of MAP. Although the estimated transfer rate constants to and from the brain (k(in) and k(out)) of MAP were higher than those of DMAP, the k(in):k(out) ratio for MAP was similar to that for DMAP. These findings indicate the equivalent ability of MAP and DMAP to penetrate into the brain after acute oral administration. The estimated values of bioavailability and fraction metabolized to DMAP increased 2.6 and 1.7 times, respectively, after chronic administration of MAP. These findings are attributable to inhibited distribution in tissue. The k(in) and k(out) values of MAP decreased, whereas those of DMAP showed no marked change. Therefore, the k(in):k(out) ratio for MAP decreased, whereas that for DMAP did not change. These results suggest that the permeability of MAP into the brain might be affected and that of DMAP is not modified by chronic administration of MAP.

Administration, Oral↗

PubMed1992

Increased aqueous flare as a result of a therapeutic dose of mannitol in humans.

To evaluate the effects of mannitol on aqueous flare (aqueous protein concentration), we administered an intravenous clinical therapeutic dose to normal young adults (average age 20.1 years), to normal older adults (average age 61.5 years), and also to patients with diabetes mellitus, systemic hypertension, or pseudoexfoliation syndrome who were about to undergo intraocular surgery (average age 66.4 years). Protein and cell levels in the aqueous were determined with a device that measures laser light scatter in the aqueous. Mannitol increased the intensity of aqueous flare. In all subjects, the intensity of aqueous flare was greatest around 1 h following drug administration; the magnitude and duration of the aqueous flare increase were significantly greater in normal older adults than in normal young adults; the magnitude was essentially the same in older adults with and without disease. The effect reversed within 6 h of drug administration in normal subjects. We consider the findings to represent changes in actual aqueous protein concentration and discuss the possible causes of this phenomenon.

Adult↗

PubMed1992

Elevated levels of serum aldolase A in patients with renal cell carcinoma.

To clarify whether serum aldolase A is a useful biomarker for renal cell carcinoma (RCC), we determined serum levels of the aldolase A isozyme by an enzyme immunoassay in patients suffering from RCC, other urological tumors, and benign urological diseases. Forty-six of 126 patients with RCC (37%) had elevated serum aldolase A. The positive rates were 23% in stage I, 40% in stage II, 63% in stage III, and 46% in stage IV. In 10 (83%) of 12 patients whose serum levels had been elevated preoperatively, these were reduced to within the normal range after nephrectomy. Four of 7 patients (57%) with progressive disease had elevated levels of aldolase A. In contrast, the positive rates were only 9.9% in 71 patients with other urological tumors and 5.8% in 52 cases of benign urological diseases. High concentrations of aldolase A isozyme in RCC tissues might be reflected in elevated serum levels. The present findings indicate that serum aldolase A is a useful biomarker for monitoring the clinical course of patients with RCC.

Biomarkers, Tumor↗

PubMed1992

An immunohistochemical study on HLA-DR expression in human meningiomas.

The expression of HLA-DR was examined in 38 cases of meningiomas with the streptavidin-biotin immunoperoxidase method using two monoclonal antibodies to HLA-DR (LN-3 and TAL-IB5) on formalin-fixed, paraffin-embedded specimens. Similar immunoreactivity was obtained with these two monoclonal antibodies. In addition to infiltrated lymphoid cells and perivascular macrophages, tumor cells themselves showed HLA-DR expression in 16 cases (42%) of meningiomas. The rate of HLA-DR-positive cases in the transitional and fibrous subtypes (64% and 67%, respectively) was higher than that in the meningotheliomatous subtype (8%). Spindle-shaped tumor cells were frequently positive for HLA-DR, whereas few of meningotheliomatous cells with plump cytoplasm were positive. Most of HLA-DR-positive cases showed no or scanty lymphoid cell infiltration, and a few cases with marked infiltration of lymphoid cells were variable for HLA-DR expression. These findings suggest little correlation between HLA-DR expression of tumor cells and the degree of lymphoid cell infiltration, but indicate an aberrant HLA-DR expression of tumor cells themselves.

Adult↗

PubMed1992

Enantioselective pharmacokinetics of homochlorcyclizine. II: Disposition and metabolism of (+)-, (-)- and racemic homochlorcyclizine after oral administration to man.

The pharmacokinetics of a single oral dose of 20 mg (+)-, (-)- and racemic homochlorcyclizine (HCZ) have been studied in humans. The formation of the quarternary ammonium-linked glucuronide was an important metabolic pathway, and the metabolic process was enantioselective as a result of differing urinary excretion rates of (+)-, (-)- and racemic glucuronide. There were significant differences between (+)-, (-)- and racemic HCZ in AUC (0-14 h) and plasma protein binding, but all HCZ enantiomers were slowly absorbed and eliminated (elimination half-lives about 11 h). The results shows help to establish a more efficient dosage regimen for HCZ therapy.

Administration, Oral↗

PubMed1992

Superficial bladder cancer treated by total cystectomy: tumour characteristics and patient survival.

Of 113 patients with bladder cancer who underwent total cystectomy from January 1980 to December 1990, 30 (27%) had superficial tumours (pTa, pTis, and pT1). Nineteen of these 30 patients (63%) were primarily treated by total cystectomy and the remaining 11 (37%) had a past history of treatment for bladder cancer. Major reasons for choice of total cystectomy were multifocal tumours, frequent recurrence, and diffuse carcinoma in situ. Histologically stage pT1, grade 3 tumours were frequently accompanied by carcinoma in situ and often by lymphatic invasion. None of the 24 patients undergoing pelvic lymphadenectomy had lymph node metastasis. Of 25 male patients 15 (60%) underwent simultaneous prophylactic urethrectomy. Two of the remaining 10 males (20%) not undergoing this additional operation died of subsequent urethral recurrence. The 5-year actuarial survival rate was 80% for the 30 patients when all causes of death were considered. It was concluded that patients with superficial bladder cancer who undergo total cystectomy without prophylactic urethrectomy require close follow-up with urethral washings for cytology to detect early urethral recurrence, an important determinant for survival.

Adult↗

PubMed1992

Emperipolesis of lymphoid cells by human follicular dendritic cells in vitro.

Isolated follicular dendritic cells (FDCs) showed true and pseudoemperipolesis of fresh tonsillar lymphocytes, even after long-term (50-day) cultivation. Emperipolesis by FDCs was not restricted by allotype specificity, nor was it inhibited by the addition of antibodies against MHC-I & II antigens. Follicular dendritic cells predominantly engulfed B-cells; monocytes and macrophages were not found between FDC cytoplasmic extensions. When highly purified T-cell populations were added to FDC cultures emperipolesis of T-cells occurred, particularly those of the CD4-positive phenotype. Mitoses appeared within 6 h in the emperipolesed lymphocytes and, after an additional 18 h, some lymphocytes exhibited apoptosis.

Antigens, Differentiation↗

PubMed1992

Relationship of the type of bcr-abl hybrid mRNA to clinical course and transforming activity in Philadelphia-positive chronic myelogenous leukemia.

We studied the type of bcr-abl mRNA for 34 patients with chronic myelogenous leukemia and analyzed for correlations among the mRNA type, the clinical outcome and the transforming activity using the tumorigenicity assay. There was no difference in the distribution of the mRNA-types (b2-a2 and b3-a2) between clinical phases. We found no correlation between the two types of bcr-abl mRNA and the chronic phase duration or survival. The DNA from 12 of 20 chronic phase patients and all five blastic phase patients showed transforming activity. Although there was no difference in the positive rate of transforming activity among the two mRNA-type groups, the blastic phase patients showed a tendency to have higher transforming activity.

3T3 Cells↗

PubMed1992

Role of the endothelial adhesion molecule VCAM in murine cardiac allograft rejection.

Murine heterotopic cardiac isografts (C57B1/6----C57B1/6) undergo transient, non-destructive inflammation that is characterized by the acquisition of microvascular endothelial reactivity with the antibody MECA 32. Cardiac allografts (C57B1/6----DBA/2) undergo destructive inflammation that is characterized by the acquisition of reactivity with the antibody M/K-2, in addition to MECA 32. M/K-2 recognizes the murine endothelial adhesion molecule, VCAM-1. Hence, there appear to be antigen-dependent and antigen-independent forms of graft inflammation. Treatment of cardiac allograft recipients with 200 micrograms/day M/K-2 antibody retarded graft loss by only a few days, and did not interfere significantly with leukocytic infiltration, as detected by limiting dilution analysis of graft-reactive CTL, despite the fact that large amounts of M/K-2 could be detected on graft microvascular endothelia and in the peripheral blood as rejection progressed. These data indicate that VCAM is apparently not essential for the leukocytic infiltration and subsequent rejection of cardiac allografts, and is not involved in leukocytic infiltration of murine cardiac isografts.

Animals↗

PubMed1992

Blood-aqueous barrier in eyes with retinal vein occlusion.

PURPOSE: The purpose of this study is to examine the changes of blood-aqueous barrier function in cases of central or branch retinal vein occlusion. METHODS: In addition to fluorophotometry of the aqueous humor and posterior vitreous, the authors used a method that quantifies protein in the aqueous (aqueous flare) by measuring the intensity of scattered laser light. RESULTS: Aqueous and posterior vitreous fluorescein concentrations and aqueous flare were significantly higher than in unaffected fellow eyes or eyes of visually normal age-matched controls both in central and branch retinal vein occlusions. They also were significantly higher in eyes with central vein occlusion than in those with branch vein occlusion. Among those eyes with central vein occlusion, aqueous and posterior vitreous fluorescein concentrations and aqueous flare were significantly higher in the hemorrhagic than in the venous stasis type of disease. Among eyes with branch vein occlusion, cases at the acute stage showed significantly higher amounts of aqueous and posterior vitreous fluorescein concentrations and aqueous flare than did those with chronic occlusion. CONCLUSION: The authors believe that increased amounts mainly reflect blood-ocular barrier disruption. Not only the blood-retinal barrier but also the blood-aqueous barrier disruption is a common sequela in the disorder.

Aged↗

PubMed1992

Active transport system of prostaglandins: clinical implications and considerations.

We hypothesize that two factors are essential in the development of epinephrine-induced cystoid macular edema (CME): (1) the stimulation of prostaglandin synthesis by some tissues, presumably the anterior uvea by epinephrine; (2) the dysfunction of the active transport (Bito's pump) which is responsible for the removal of prostaglandins from intraocular fluids. We conducted several experimental studies to confirm these hypotheses. The results strongly suggest that epinephrine maculopathy is induced by a mechanism involving prostaglandins or, possibly, other related eicosanoids and not simply by epinephrine itself, as has been postulated. This suggests the existence of some common factors in the pathogenesis of epinephrine maculopathy and aphakic or pseudophakic CME.

Animals↗

PubMed1992

Requirement for VLA-4 and VLA-5 integrins in lymphoma cells binding to and migration beneath stromal cells in culture.

Physical interaction between human lymphomas and murine bone marrow derived stromal cells were studied. Nalm-6 pre-B cells adhered to BMS2 stromal cells and subsequently migrated beneath them, while Ramos Burkitt lymphoma cells, adhered but did not migrate. Four mAbs were established against Nalm-6 cells, which were able to block initial adhesion of Nalm-6 cells. Two of them were directed against the alpha 4 chain of VLA-4, and other two recognized the beta 1 chain of VLA integrins. Therefore, the initial adhesion of Ramos and Nalm-6 cells to BMS2 was largely mediated by the VLA-4 integrin expressed on lymphocytes. The corresponding ligand on stromal cells appears to be VCAM-1, because antibodies against murine VCAM-1 blocked the adhesion. However, antibodies against the alpha chain of VLA-4 were not capable of blocking subsequent migration beneath stromal cells. In contrast, antibodies against the beta chain of VLA integrins blocked the migration beneath stromal cells as well as the initial adhesion. Because a common beta chain can be shared among integrins, the role of other VLA integrins in Nalm-6 cells migration was investigated. VLA-5 and VLA-6 as well as VLA-4 were expressed on Nalm-6 cells, but not on Ramos cells. Additional blocking experiments revealed that VLA-4 and VLA-5 are likely to work in concert to mediate the migration of Nalm-6 cells beneath stromal cells. Thus, particular VLA integrins appear to be responsible not only for lymphocyte adhesion but also for migration with respect to stromal cells. These findings may have implications for cell-cell interactions and directed migration of lymphocytes in bone marrow and other tissues.

Animals↗

PubMed1992

Treatment of Langerhans cell histiocytosis in children with etoposide.

Ten children with Langerhans cell histiocytosis (LCH) were treated with etoposide. For five patients, this was the initial diagnosis. The other five had failed to respond to previous therapies. Etoposide (100 mg/m2) was given intravenously twice a week for 4 weeks, followed by maintenance therapy every 2 to 4 weeks for 2 years. All 10 patients responded to etoposide, and 6 of them (60%) have been in complete remission for 3 to 36 months without any side effects. One patient relapsed with diabetes insipidus, one with a soft tissue mass, and two others developed multiple bone lesions. Chemotherapy with etoposide appears to be effective and safe for the treatment of children with systemic LCH.

Adolescent↗

PubMed1992

Immunohistochemical localization of calmodulin in the human testis [corrected].

The localization of calmodulin in the normal human testis was studied by the indirect immunoperoxidase method. Three different types of fixative were used: phosphate-buffered formalin, Bouin's solution or Carnoy's solution. Immunoreactivity specific for calmodulin was not detectable in the testis fixed in Carnoy's solution. The specimens fixed in phosphate-buffered formalin and in Bouin's solution were stained. The immunostaining for calmodulin was observed in pachytene spermatocytes, secondary spermatocytes and round spermatids but not in spermatogonia, or in pre-leptotene, leptotene and zygotene spermatocytes, elongated spermatids, spermatozoa or Leydig cells. Sertoli cells were not stained or were stained slightly. Among pachytene spermatocytes, the cells at the early stage were barely stained but those at the middle and late stages were slightly and intensely stained, respectively. The present report provides the first confirmation of the localization of calmodulin in the human testis.

Adult↗