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Biomedical subjects

T Inui

Publications and source records attributed to T Inui.

At least 163 records · Page 9Linked to original sources
PubMed1989

Incidence of precancerous foci of mammary glands and growth rate of transplantable mammary cancers in sialoadenectomized mice.

Sialoadenectomies performed on 8-week-old female SHN and GR mice markedly reduced the numbers of precancerous and cancerous lesions in their mammary glands that had been mildly hypoplastic; the mice were necropsied when they were 30 weeks old. The success rate of the mammary cancer transplantation to isogenic male SHN or C3H mice was lower in the sialoadenectomized animals, and growth of the grafted tumors was delayed after gland removal. Some tumor development resumed in the hosts that received mouse epidermal growth factor after surgery. Therefore, we believe this growth factor may play a role in the multistage process of mouse mammary carcinogenesis.

Animals↗
PubMed1989

Structure-activity relationship of endothelin: importance of charged groups.

Endothelin (ET)-related peptides including ET-1 (1-39) were synthesized, and their constricting activity in rat pulmonary artery rings and pressor activity in unanesthetized rat were measured to elucidate their structure-activity relationship. The vasoconstrictor activities of ET-2, ET-3 and sarafotoxin S6b were one-half, one-60th and one-third that of ET-1, respectively. Such differences in biological activities should mainly arise from sequence heterogeneity at the N-terminal portion, especially at positions 4 to 7. All of the blocked ETs at the amino or carboxyl termini showed greatly decreased activities. A monocyclic analog, in which Cys3 and Cys11 were replaced by Ala, showed one-third the activity of ET-1; however, its deamino dicarba analog was almost completely inactive. Significant activities were retained even with replacement of amino acids at positions Ser4, Ser5, Leu6, Met7, Lys9, Tyr13, and Trp21 by Ala, Ala, Gly, Met(0), Leu, Phe, and Tyr or Phe, respectively. On the other hand, replacement of Asp8, Glu10 and Phe14 by Asn, Gln and Ala, respectively, resulted in complete loss of the biological activity. These results indicated that two disulfide bonds in ET molecule were not essential for the expression of vasoconstricting activity. Both terminal amino and carboxyl groups, carboxyl groups of Asp8 and Glu10, and the aromatic group of Phe14 seemed to be contributing, more or less, to the expression of the biological activities.

Animals↗
PubMed1989

Immunolocalization of the human basal epithelial marker monoclonal antibody 312C8-1 in normal tissue and mammary tumours of rodents.

Using immunoperoxidase staining of monoclonal antibody 312C8-1 against 51,000 dalton human keratin polypeptide, immunolocalization was observed in frozen sections of normal tissue and mammary tumours of adult female mice and rats. In normal tissue, the epitope was recognized in myoepithelial cells of the mammary, sweat and salivary glands, and in basal and suprabasal cells of the epidermis. However, the antibody did not react with luminal epithelial cells of the above glands or with mesenchymal cells. In spontaneous mammary tumours of mice, marker-positive tumour cells were distributed only in the outer layer of adenocarcinoma Type A, while they were scattered in some foci of adenocarcinoma Type B, and encircled the epithelial foci of pregnancy dependent tumours (plaque). All layers of epidermoid structures in adenoacanthoma revealed positivity. In rat mammary tumours induced by local dusting with 7, 12-dimethylbenz(a)anthracene (DMBA) powder, the staining pattern of benign tumours was comparable to that of the normal mammary gland. But, in addition to basally situated cells, marker-positive tumour cells were found scattered in the foci of adenocarcinoma, and were not restricted to basal cells in squamous cell carcinoma. The marker was not found in sarcomatous tissue. This antibody can therefore also be applied to rodents, and the staining pattern can be used to identify the epithelial subclass specific marker in normal tissue and in mammary tumours.

Adenocarcinoma↗
PubMed1989

Prostaglandin E2 and F2 alpha inhibit growth of human gastric carcinoma cell line KATO III with simultaneous stimulation of cyclic AMP production.

The effects of prostaglandins (PGs) on the growth of human gastric carcinoma cell line KATO III were investigated. PGE2 as well as PGF2 alpha significantly and dose-dependently inhibited the growth of this gastric carcinoma cell line (PGE2 greater than PGF2 alpha). This inhibition of cell growth by the PGs was associated with the increase in cyclic AMP production (PGE2 greater than PGF2 alpha), whereas inositol-phospholipid turnover was not affected by either PGE2 or PGF2 alpha as assessed by the formation of 3H-inositol phosphates. Furthermore, the proliferation of these gastric carcinoma cells was also suppressed by the administration of forskolin as well as of dibutyryl cyclic AMP. These results suggest that PGE2 and PGF2 alpha inhibit the growth of cultured human gastric carcinoma cells KATO III via stimulation of cyclic AMP production.

Bucladesine↗
PubMed1989

Presence and release of calcitonin gene-related peptide in rat stomach.

Immunoreactive (IR)-calcitonin gene-related peptide (CGRP) was identified throughout the entire stomach of rats, being most highly concentrated in the pyloric region, and the concentrations in muscular layers being higher than those in mucosal layers. In addition, IR-CGRP was also present in the venous effluent from isolated perfused rat stomach, and its release was stimulated by dibutyryl cyclic AMP or theophylline but not by glucagon. Gel chromatography as well as HPLC of both tissue extracts and gastric perfusate showed three identical major peaks of IR-CGRP, one of which coeluted with synthetic CGRP. These results suggest that CGRP in the stomach plays a role in the regulation of gastric function.

Animals↗
PubMed1989

Introduction of information during the initial medical visit: consequences for patient follow-through with physician recommendations for medication.

While negotiation of treatment decisions in the medical visit has long been recognized as an important interviewing skill, limited work has been done to investigate how doctors and patients negotiate what information is relevant in understanding the patient's problem. In this research we tested how the introduction of information reflecting both the patient's and physician's perspective is related to the patient's adherence to physician recommendations for medication. Introduction of information was defined as bi-directional if patients independently offered information or behavior as frequently as they provided the information or exhibited behavior that physicians requested. Thirty random samples of audiotaped dialogue were used to construct estimates of introduction of information during the history, examination, and consultation phases of initial ambulatory care visits of 45 older male patients. The data demonstrate that bi-directional introduction of information during the examination segment explains more than half of the variance in patient adherence to physician recommendations for new medication. These findings support the idea that physician willingness to allow patients to contribute input may contribute to the partnership's arrival at treatment decisions that have meaning for both.

Adult↗
PubMed1989

The Sickness Impact Profile as a measure of the health status of noncognitively impaired nursing home residents.

The Sickness Impact Profile (SIP) is a multidimensional, behaviorally based measure of the health status that has been successfully used in a wide range of applications. The characteristics of this measure have not been assessed with nursing home residents. The purpose of this study was to assess the feasibility, reliability (internal consistency), validity, and comprehensiveness of the SIP as a measure of the health status of a selected group of nursing home residents. One hundred sixty-eight veterans residing in community and VA nursing homes responded to a questionnaire consisting of the SIP, Index of Activities of Daily Living, Barthel Index, Life Satisfaction Index Z, and the Philadelphia Geriatric Center Morale Scale. In general, the respondents correctly interpreted instructions; reliability and validity were supported; and the SIP was found to provide a comprehensive assessment of physical function. Adding a measure of psychologic well-being to a study protocol involving this population may, however, provide additional useful information regarding this construct.

Activities of Daily Living↗
PubMed1989

Meta-analysis of home-care effects on mortality and nursing-home placement.

This meta-analysis was designed to illustrate how the relatively new discipline of meta-analysis could be employed in health-services research. In pursuit of this goal, the results of 13 studies on the effect of home care on mortality and nursing-home placements were examined. The analysis demonstrated a small, beneficial effect of home care on mortality, which fell short of statistical significance. Study-to-study variation in the odds ratio was found that was not strongly associated with differences in the study samples, designs, or interventions as categorized here. The analysis produced stronger evidence of a reduction in nursing-home placements. In this case, differences in study design explained much of the heterogeneity in results, with the randomized controlled trials showing considerably weaker effects. The analysis also provides insight into the benefits and limitations of alternative meta-analytic methods. The "odd man out" method recently described by Walker et al. detected statistically significant heterogeneity of effects across studies for nursing-home placement, but not for mortality. Loglinear modeling made it easier to detect and explore study-to-study variation in home-care effects.

Confidence Intervals↗
PubMed1989

Calcitonin gene-related peptide receptor antagonist human CGRP-(8-37).

From this study, we predicted that the human calcitonin gene-related peptide (hCGRP) fragment hCGRP-(8-37) would be a selective antagonist for CGRP receptors but an agonist for calcitonin (CT) receptors. In rat liver plasma membrane, where CGRP receptors predominate and CT appears to act through these receptors, hCGRP-(8-37) dose dependently displaced 125I-[Tyr0]rat CGRP binding. However, hCGRP-(8-37) had no effect on adenylate cyclase activity in liver plasma membrane. Furthermore, hCGRP-(8-37) inhibited adenylate cyclase activation induced not only by hCGRP but also by hCT. On the other hand, in LLC-PK1 cells, where calcitonin receptors are abundant and CGRP appears to act via these receptors, the bindings of 125I-[Tyr0]rat CGRP and 125I-hCT were both inhibited by hCGRP-(8-37). In contrast to liver membranes, interaction of hCGRP-(8-37) with these receptors led to stimulation of adenosine 3',5'-cyclic monophosphate (cAMP) production in LLC-PK1 cells, and moreover, this fragment did not inhibit the increased production of cAMP induced not only by hCT but also by hCGRP. Thus hCGRP-(8-37) appears to be a useful tool for determining whether the action of CGRP as well as that of CT is mediated via specific CGRP receptors or CT receptors.

Adenylyl Cyclases↗
PubMed1988

Necrotizing effect of ethanedimethanesulfonate on spontaneously occurring Leydig cell tumors in old F344 rats.

Thirty 18-month-old male F344/DuCrj rats were divided into the following groups: 10 untreated controls; eight vehicle-injected controls; and 12 ethanedimethanesulfonate (EDS)-injected rats. Untreated controls were killed immediately to check for testicular tumor incidence. In rats of the test group, a 75-mg/kg dose of EDS dissolved in dimethyl sulfoxide:water (1:3) was injected i.p. At intervals of 1, 2, 3, and 10 days after injection, two vehicle-injected control rats and three EDS-injected rats were sacrificed, and the testes were fixed by vascular perfusion. The midsagittal sections of all the fixed testes were examined to determine the incidence of macroscopic Leydig cell tumors, and some tumor tissues of the injection-treated groups were also investigated ultrastructurally. In 28 of 30 animals, a total of 78 Leydig cell tumors could be distinguished. Extensive and severe necrotic alterations accompanying fresh, multiple hemorrhages in early stages and reparative changes in later stages could be observed in a total of 78% of the 32 tumors examined from the EDS-injected group. The tumor cells exhibited ultrastructurally degenerative changes such as chromatin condensation and cytoplasmic vacuolation from 1 day after EDS injection. Therefore, EDS may be a necrotic agent for rat Leydig cell tumor.

Animals↗
PubMed1988

Receptors for calcitonin gene-related peptide on the rat liver plasma membranes.

Specific binding sites for calcitonin gene-related peptide (CGRP) were identified in the rat liver plasma membrane. The binding of 125I-[TyrO]rat CGRP to rat liver plasma membrane was time dependent, saturable and reversible. Scatchard analysis of the data revealed a single class of binding sites with apparent dissociation constant of 260.8 pM and a maximal binding capacity of 26.6 fmol/mg of protein. Rat, chick, and human CGRP and their synthetic analogues inhibited label binding in a dose-dependent manner with relative potencies as follows; chick greater than rat greater than human greater than [TyrO]rat CGRP. Salmon, human and [Asu1'7]eel calcitonin also inhibited label binding but only at higher concentrations. These results clearly indicate the presence of specific binding sites for CGRP in rat liver plasma membrane and suggest that CGRP has possible biological actions on the rat liver.

Animals↗
PubMed1988

Properties of human visual memory for block patterns.

Several characteristics of human short-term visual memory (STVM) were specified through a series of experiments, by using block patterns (BPs) of varying complexity and matrix size (n-by-n). For each matrix size, BPs with high and low complexity were formed (i.e. n-by-n-H and n-by-n-L). In experiment I, the characteristics of the acquisition process were examined through a recall task. The recall rate for a single glance (exposure time less than 0.3 s) is more than 90% for 3-by-3 and 4-by-4-L BPs. For 4-by-4-H BPs, an improvement in recall rate was not found even when exposure time was increased to 2.4s. The recall rate for 6-by-6-H, 7-by-7, and 8-by-8 BPs did not change even when the exposure time was increased to 9s. In experiment II, the characteristics of the STVM decay process were examined using a recall task. Though a difference between the 4-by-4-L and 4-by-4-H acquisition rates was found, no difference was found in the forgetting rates. No decay was found for 6-by-6 BPs. Furthermore, the information obtained during a short duration was not forgotten for 4-by-4, and 6-by-6 BPs. It was concluded from these results that: 1) The acquisition rate into STVM depends upon figural complexity. 2) The decay rate does not depend upon figural complexity. 3) The limit of STVM was between 4-by-4-L, and 4-by-4-H BPs.(ABSTRACT TRUNCATED AT 250 WORDS)

Cybernetics↗
PubMed1988

Immunohistochemical localization of myoepithelial cells and basement membrane in normal, benign and malignant human breast lesions.

Distributions of actin and type IV collagen were investigated immunohistochemically as markers for myoepithelial cells and basement membranes. Carnoy's and Methacarn-fixed, paraffin-embedded tissues from 103 human breast lesions from 103 patients were examined; 65 with carcinomas, 27 with mastopathies, 9 with fibroadenomas and 2 with phyllodes tumours. Fifty-five samples of the normal mammary gland tissue adjacent to tumours were also included for comparison. In normal breast and benign breast diseases, type IV collagen was identified around the mammary glandular cells and actin-positive cells were demonstrated to attach to basement membranes. In noninvasive carcinomas, type IV collagen was found as a continuous lining around a cell nest, while actin-positive cells were usually absent in ductal but quite numerous in lobular carcinomas. In invasive carcinomas, type IV collagen was fragmented or absent and actin-positive cells were very uncommon around the fragmentary basement membranes. These results suggest that the different distributions of myoepithelial cells and basement membrane material is useful in the differential diagnosis of surgical pathology of the breast.

Actins↗
PubMed1988

Morphological and biological characteristics of mammary tumours induced by the direct application of DMBA powder to rat mammary glands.

Mammary tumours were induced by the direct dusting of 1 mg, 7,12-dimethylbenz(a)anthracene (DMBA) powder onto the mammary gland of both 30-day-old female and male Sprague-Dawley rats, and the tumours were examined histologically. Mammary tumours developed in 43/43 (100%) of the females 11 to 20 weeks after DMBA dusting and 16/23 (70%) of the males 18 to 28 weeks after dusting, while non-mammary spindle cell sarcomas occurred in 5/23 (22%) of the males 15 to 24 weeks after dusting. A variety of benign and malignant mammary tumours of epithelial and/or mesenchymal origin were induced, which are comparable to human mammary tumours. Different histological patterns were observed in different areas of the same tumours. Ovariectomy revealed hormone (ovary)-dependency in 10/17 (59%) of the tumours, revealing regressing epithelial and proliferating mesenchymal tumour elements on histological examination.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1988

Dual action of protein kinase C activation in the regulation of insulin release by muscarinic agonist from rat insulinoma cell line (RINr).

The role of protein kinase C in muscarinic agonist-induced insulin release from rat insulinoma cells was investigated. The dose-dependent stimulation of insulin secretion by carbamylcholine (carbachol) was associated with dose-dependent increase in the release of 3H-inositolphosphates from prelabeled rat insulinoma cell line (RINr) cells. After preincubation with 32P-orthophosphates, carbachol also evoked a rapid decrease in 32P-labeling of phosphatidylinositol-4,5-bisphophate with concomitant increase in 32P-labeling of phosphatidic acid. Furthermore, carbachol significantly increased membrane-associated protein kinase C activity with a simultaneous decrease of its activity in cytosol. Although phorbol-12,13-dibutyrate (PDBu), a protein kinase C activator, also stimulated insulin release, insulin secretion induced by concomitant administration of carbachol and PDBu was clearly less than the level expected on the basis of an additive action. Moreover, PDBu significantly inhibited inositolphospholipid turnover stimulated by carbachol. Finally, PDBu inhibited the binding of 3H-scopolamine binding revealed that PDBu decreased the number of muscarinic receptors without altering its affinity. These findings suggest that activation of protein kinase C not only mediates muscarinic stimulation of insulin secretion from RINr cells but also operates a negative feedback mechanism in a signal transduction system, at least in part, via down-regulation of muscarinic receptors.

Adenoma, Islet Cell↗
PubMed1988

Calcitonin gene-related peptide stimulates adenylate cyclase activation via a guanine nucleotide-dependent process in rat liver plasma membranes.

To evaluate the functional relationship between the liver calcitonin gene-related peptide (CGRP) receptor and guanine nucleotide-binding proteins, we investigated the effects of nucleotides not only on adenylate cyclase activation by CGRP, but also on 125I-[Tyr0]rat CGRP binding to rat liver plasma membranes. In the presence of GTP, rat CGRP stimulated adenylate cyclase activity in a dose-dependent manner in rat liver plasma membranes, and this effect was reduced in the absence of GTP. Salmon calcitonin also enhanced adenylate cyclase activation in the presence of GTP, but only in higher concentrations. On the other hand, guanine nucleotides not only decreased 125I-[Tyr0]rat CGRP binding to rat liver plasma membranes, but also accelerated the dissociation of label binding, and the removal of Mg2+ from incubation medium attenuated this inhibitory action of GTP on 125I-[Tyr0]rat CGRP binding to membranes. Scatchard analysis of the data revealed that the reduction of 125I-[Tyr0]rat CGRP binding by GTP was due to the decrease in binding affinity without a significant change in binding capacity. These findings lead us to conclude that binding of CGRP to its receptors activates adenylate cyclase in rat liver plasma membranes via a guanine nucleotide-dependent process, suggesting the involvement of guanine nucleotide-binding stimulatory protein in the action of CGRP.

Adenylyl Cyclases↗
PubMed1988

[Apocrine carcinoma of the breast--a morphologic comparison of the apocrine sweat glands and the apocrine metaplastic epithelia in mastopathy].

An operatively removed apocrine carcinoma of the breast from a 62-year-old Japanese lady has been observed by the ABC method, using the monoclonal antibody 115D8. The cancer cells and metaplastic epithelia exhibited similar ultrastructural findings (an apical snout, apocrine granules, etc.) as the apocrine sweat gland cells, although no evidence of apocrine secretion could be detected. The immunohistochemical testing, using monoclonal antibody, 115D8, showed an apical, linear, dot-like, staining in the supranuclear regions on the apocrine sweat gland cells and on the apocrine metaplastic cells of the mammary gland. Similar stainability also was observed in the well-differentiated area of the apocrine carcinoma, while a heterogeneity in staining, such as unstained cells and diffuse cytoplasmic-stained cells were found in the poorly-differentiated areas. These abnormal staining patterns indicate the malignant changes of the apocrine cells.

Antibodies, Monoclonal↗