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Biomedical subjects

K Kurihara

Publications and source records attributed to K Kurihara.

At least 163 records · Page 9Linked to original sources
PubMed1993

Bradykinin-stimulated transient modulation of epidermal growth factor receptors in A-431 human epidermoid carcinoma cells.

Of nine biological factors (ATP, bradykinin, vasopressin, substance P, angiotensin II, norepinephrine, epinephrine, 12-tetradecanoylphorbol 13-acetate (TPA), and A23187 calcium ionophore) examined, bradykinin, as well as ATP, TPA, and A23187, significantly increased the phosphorylation of epidermal growth factor (EGF) receptors and reduced the binding of EGF to their high-affinity site. The reduction in EGF binding by bradykinin, ATP, and TPA was similarly reversed by concomitant incubation with staurosporine, a protein kinase C inhibitor, implying that the phosphorylation of EGF receptors was catalyzed probably by a protein kinase C of the same or similar type in each case. This possibility was confirmed by the fact that the major phosphorylation site of EGF receptors by the stimulation with either bradykinin, ATP, or TPA was the same (Thr-654). Different from the stimulations with ATP and TPA, the effect of bradykinin of decreasing the high-affinity EGF binding was transient (a minimum binding at 2.5 min); the reduced EGF binding was, however, sustained for up to 30 min in the presence of calyculin A, a phosphoprotein phosphatase inhibitor. Moreover, the homogenate prepared from bradykinin-stimulated A-431 cells had stronger dephosphorylation activity for phosphorylated EGF receptors than that from control cells. These results suggest that bradykinin stimulates both the protein kinase C system and a phosphoprotein phosphatase(s) activity in A-431 cells. Such biphasic effects of bradykinin to phosphorylate and dephosphorylate EGF receptors via protein kinase C and a phosphoprotein phosphatase, respectively, imply a homeostatic control of receptor function in regulating phosphorylation level by the same bioactive factor.

Alkaloids↗
PubMed1993

Loss of VLA-2 collagen receptor in breast carcinoma, facilitating invasion and metastasis.

The integrin VLA-2 as a collagen receptor and VLA-5 as a fibronectin receptor were detected immunohistochemically in normal, benign tumor and carcinoma tissues of the breast. Both proteins were also detected by Western-blot analysis in some carcinoma cases. Epithelial and myoepithelial cells of both normal breast and benign tumor were in all cases immunoreactive for VLA-2 in the plasma membrane. Carcinoma cells in the invasive component were not immunoreactive for VLA-2 in 31 (46%) of 67 cases. Carcinoma cells in the intraductal components were negative for VLA-2 in only 4 (11%) of 36 cases, while 20 cases (56%) showed weak expression and 12 cases (33%) showed strong expression. Metastatic carcinoma cells in the lymph nodes of 6 cases showed no immunoreactivity except in one case, whereas, again with the exception of one case, the carcinoma cells in the primary tumors did show VLA-2 expression. With regard to VLA-5, there was no difference in its expression in the invasive components and the intraductal components. These findings suggest that the loss of VLA-2 plays a role in the invasion and metastasis of breast carcinoma.

Adult↗
PubMed1993

A role of VLA-6 laminin receptor in invasion of breast carcinoma.

The integrin VLA-6 as a laminin receptor and laminin as a ligand for laminin receptor were detected immunohistochemically in normal, benign tumor and carcinoma tissues of the breast. Epithelial cells of both normal breast and benign tumor were in almost all cases strongly immunoreactive for VLA-6 in the plasma membrane. Carcinoma cells in 34 of 70 cases (49%) with an invasive component were not immunoreactive for VLA-6, and no carcinoma cells showed strong positivity. Although carcinoma cells in only four of 51 cases (8%) with intraductal components were negative for VLA-6, 37 cases (72%) showed weak expression of VLA-6 and 10 cases (20%) showed strong expression of VLA-6. A concordant expression of VLA-6 on carcinoma cells and laminin around carcinoma cell nests with an invasive component was observed, and VLA-6 expression in carcinoma cells was correlated to tubular formation in carcinoma cell nests as an indicator of differentiation. These findings suggest that loss of VLA-6 plays a role in the invasion of breast carcinoma, and that VLA-6 laminin receptor and laminin may contribute to tubular differentiation of breast carcinoma cells.

Breast Diseases↗
PubMed1993

Distribution of laminin, type IV collagen and fibronectin in the invasive component of breast carcinoma.

Laminin, type IV collagen and fibronectin were examined immunohistochemically in the invasive component of breast carcinomas. Laminin was expressed around the invasive carcinoma cell nests in 38 (54%) of 71 cases. Immunoreactivity for type IV collagen was observed around the invasive carcinoma cell nests or the stroma apart from carcinoma cells in 44 (80%) of 55 cases. Fibronectin was strongly expressed in the stroma only in 75 (99%) of 76 cases. The expression of laminin significantly correlated with tubular formation in the invasive carcinoma cell nests and showed a tendency to be correlative to estrogen receptor (ER) and progesterone receptor (PgR) of carcinoma tissue, but no correlation among laminin expression, histological type, the age of patients, tumor size and lymph node metastasis was noted. Type IV collagen and fibronectin did not correlate to any clinicopathological factors such as histological type, grade of differentiation, the age of patients, tumor size, lymph node metastasis, ER and PgR status. No concordant expression of these extracellular matrices was seen.

Breast Neoplasms↗
PubMed1993

Myxoma of the breast: report of a case with unique histological and immunohistochemical appearances.

A case of myxoma of the breast is reported. The patient, a 19 year old Japanese woman, showed a lump in the left breast which had enlarged gradually over 3 years. A tumor measuring 5 x 5 x 4.5 cm was located mainly in the mammary parenchyma, but partially involved the overlying subcutaneous tissue. Histologically the tumor was multinodular and each nodule consisted of an abundant myxoid substance with a few spindle or stellate mesenchymal cells. The presence of hyaluronic acid was observed in the myxoid area, and a few constituent cells showed immunoreactivities for S-100 protein and alpha 1-antichymotrypsin. Electron microscopic studies revealed that some constituent cells looked like undifferentiated mesenchymal cells, while others showed a differentiation similar to fibroblast or histiocyte. These findings suggest that the constituent cells might derive from totipotential primitive mesenchymal cells.

Adult↗
PubMed1993

Large enhancement of canine taste responses to amino acids by salts.

The effects of salts on the canine taste responses to amino acids were examined by recording the activity of the chorda tympani nerve. 1) The tonic responses to most amino acids examined were significantly enhanced by the presence of various salts. 2) The degree of the enhancement varied with the species of amino acid and salt. The responses to most amino acids were enhanced by sodium, potassium, and calcium salts, but not enhanced by magnesium salts. The response to methionine, for example, was enhanced by NaCl, but not by Na phosphate of equimolar Na+. 3) The responses to glycine and alanine were suppressed by high concentrations of NaCl. 4) The presence of salts (NaCl and CaCl2) enhanced the responses to amino acids without affecting the thresholds for the amino acids, suggesting that the presence of the salts did not change the affinity of amino acids to the receptor sites. 5) The enhancing effects of salts on the responses to amino acids could not be explained in terms of permeability of cation and anion of salts. It was speculated that the binding of cation and anion of salts on the receptor membranes induces exposure of the receptor sites for amino acids available for binding of amino acids.

Amino Acids↗
PubMed1993

Transduction mechanisms in the olfactory and vomeronasal organs of turtles.

It is generally believed that odorants bind to receptor proteins and activate cAMP-dependent channels located in olfactory cilia. In the present paper, we discuss whether or not this mechanism holds for in vivo transduction in the olfactory and vomeronasal organs of a turtle: (1) Elimination of salts from the olfactory epithelium did not affect the responses to odorants; changes in concentration of NaCl or CaCl2 did not affect the olfactory responses. (2) The sensitivity of the vomeronasal system to various general odorants was essentially similar to that of the olfactory system, although the vomeronasal cells have no cilia. Elimination of salts from the surface of the vomeronasal organ, similar to the olfactory system, did not affect responses to odorants. (3) Liposomes having certain lipid compositions responded to odorants with a sensitivity comparable to that in the olfactory system. The liposomes containing phosphatidylserine (PS) exhibited strong responses, especially to fatty acids. (4) Application of PS-containing liposomes to the olfactory epithelium greatly enhanced the responses to fatty acids. The results suggest that the cation channels located at olfactory cilia may not contribute to in vivo olfactory transduction. The results also suggest that lipids in olfactory receptor membranes are important in odor reception.

Animals↗
PubMed1993

[Dysphagia in Parkinson disease].

Clinical studies were carried out on 97 patients with Parkinson disease. Radiological and manometric studies were performed on 9 patients. The patients histories revealed about 30% had a feeling of dysphagia. Recognition of dysphagia especially in the second phase increases with an increase in duration of the disease and with deterioration of ADL. More than 40% of patients who suffered more than ten years or whose conditions were more severe than third degree of Yahr's scale complained of dysphagia. Some patients felt the disturbance in the first or the third phase of swallowing from the early stage. X-ray studies disclosed abnormal findings in 6 patients including delayed initiation of swallowing (3 patients), vallecular stasis (3 patients), aspiration (2 patients) and slight dilatation of lower esophagus (2 patients). Abnormal findings in oral phase were more severe than those in pharyngeal phase. Manometric study showed high intraluminal resting pressure of the lower esophagus and loss of negative wave in the lower esophageal sphincter after swallowing, suggesting the disturbance of smooth muscle of esophagus. Cricopharygeal dysfunction and disturbance of peristaltic wave of esophagus were not obvious. Pharynx and striated muscle of esophagus were not so severely involved. Dysfunction of tongue and lower esophagus are thought to be probably due to the disturbance of the extrapyramidal system and the autonomic nervous system, respectively.

Adult↗
PubMed1993

[Dysphagia in multiple system atrophy--radiological and manometric study].

Clinical, radiological and manometric studies on 27 patients with multiple system atrophy (MSA) were performed to investigate the characteristics of dysphagia. Patients of MSA were divided into 4 groups: 9 patients of OPCA I (duration < 5 years), 6 patients of OPCA II (duration > or = 5 years), 8 patients of SDS (duration < 5 years) and 4 patients of SND (duration < 5 years). A clinical history was taken to distinguish the two types of dysphagia, that is to say, swallowing disturbance in a narrow sense and passage disturbance. In the radiological study, each phase of swallowing was observed by X-rays with contrast medium (Dionosil). In the manometric study, intraluminal resting pressure in the esophagus and pressure of esophageal contraction after swallowing were measured. The results were as follows: 13 patients (OPCA I 2, OPCA II 6, SDS 2, SND 3) experienced the sensation of swallowing disturbance in a narrow sense and 4 patients (OPCA I 1, OPCA II 1, SDS 1, SND 1) had the feeling of passage disturbance. X-ray studies showed 6 patients (OPCA I 0, OPCA II 1, SDS 1, SND 4) had disturbance of lingual movements, 11 patients (OPCA I 1, OPCA II 5, SDS 3, SND 2) had pooling in piriformis sinus and 14 patients (OPCA I 3, OPCA II 4, SDS 5, SND 2) had slight dilatation of the lower esophagus. In the manometric study, 12 patients (OPCA I 4, OPCA II 4, SDS 3, SND 1) were shown to have low intraluminal resting pressure of the upper esophageal sphincter.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Interleukin-5 selectively enhances the chemotactic response of eosinophils obtained from normal but not eosinophilic subjects.

We have attempted to determine whether interleukin-5 (IL-5), a cytokine that selectively affects eosinophil (as opposed to neutrophil) differentiation and activation, also modulates eosinophil migrational responses. Using a modified Boyden chemotaxis assay, IL-5, IL-3, and granulocyte-macrophage colony-stimulating factor (GM-CSF) gave a weak locomotory response for eosinophils from normal nonatopic subjects (optimal at 10(-11), 10(-8), and 10(-9) mol/L, respectively), but not for eosinophils from subjects with an eosinophilia associated with asthma and/or allergic rhinitis. In contrast, IL-5 and IL-3 had no effect on neutrophils, while GM-CSF was chemotactic for neutrophils over a limited concentration range, optimal at 10(-8) mol/L. When eosinophils from normal subjects were incubated with IL-5 (10(-9) mol/L), the locomotory response to platelet-activating factor (PAF; 10(-8) mol/L, P less than .05), leukotriene B4 (LTB4; 10(-6) mol/L, P less than .01), and N-formyl-methionyl-leucyl-phenylalanine (FMLP; 10(-8) mol/L, P less than .01) was significantly enhanced. The percentage enhancement of eosinophil locomotion by IL-5 was greater for eosinophils from normal as compared with subjects with an eosinophilia associated with asthma (P less than .05 for PAF and LTB4; P less than .01 for FMLP). Preincubation of eosinophils from normal subjects with IL-5 (10(-9) mol/L) attenuated the subsequent locomotory response to IL-5 (10(-12) and 10(-11) mol/L, P less than .05). Therefore, the observed refractoriness of eosinophils from eosinophilic subjects to both directional migratory and priming effects of IL-5 in vitro, may reflect a deactivation process resulting from prior exposure in vivo. The selective priming of eosinophil but not neutrophil locomotion by IL-5 suggests that this cytokine may play a significant role in the preferential accumulation of eosinophils at sites of allergic inflammation.

Asthma↗
PubMed1992

Desmoplastic malignant melanoma of the gingiva.

A case of desmoplastic melanoma in a 58-year-old man is reported. This rare malignancy occurred in the maxillary alveolus, appearing as an epulis. Histologically, the tumor was flanked by melanocytic proliferation in the adjacent mucosae. At the time of local recurrence after partial maxillectomy, the tumor showed a polypoid growth, with an increase in cellularity and mitotic rate resembling spindle cell carcinoma. The value of immunostaining for diagnosis is stressed.

Humans↗
PubMed1992

Cranial fasciitis of childhood: a case report.

Cranial fasciitis of childhood is very rare, only 17 cases having been reported in the literature. We report an additional case of this rare disease. The patient was a 5-year-old boy who complained of left exophthalmos and double vision. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a large epidural mass in the left frontal region that had invaded into the underlying anterior skull base. The tumor showed homogeneous, low density with nonhomogeneous contrast enhancement on the CT scans, and low intensity on the T1-weighted and high intensity on the T2-weighted MRI images. A whitish-pink, elastic, hard tumor was revealed in the epidural space in the left anterior cranial fossa, which was totally excised with curettage of the affected anterior skull base. The origin of the tumor was suspected to be the fibrous connective tissue of the sphenofrontal suture. The histological diagnosis was that of cranial fasciitis. There was no evidence of recurrence 1 year postoperatively.

Child, Preschool↗
PubMed1992

Epithelial hyperplasia of the breast. Comparison of incidence between cases of breast carcinoma and control autopsy specimens with immunohistochemical observation of blood group antigens.

Epithelial hyperplasia in the duct, ductule or lobule of the breast is a very common lesion and has been considered to carry a risk of subsequent invasive carcinoma. However, it is not known whether epithelial hyperplasia can transform into carcinoma or whether malignant change occurs de novo. We analyzed the incidence of epithelial hyperplasia of the breast by making a comparison between cases of breast carcinoma and control autopsy specimens, and studied differences in the membrane antigens of the constituent cells using immunohistochemical staining of blood group antigens. It was found that the frequency of epithelial hyperplasia was higher in the cases of breast carcinoma. The lesions showed loss of A, B and H antigens at high frequency, and the proportion of lesions showing loss of these antigens became higher as the atypia of the lesion increased. On the other hand, expression of Lea antigen was observed more frequently in atypical epithelial hyperplasia or in situ carcinoma than in ordinary epithelial hyperplasia. These findings suggest possible transformation from epithelial hyperplasia to carcinoma, and indicate that atypical epithelial hyperplasia may be precancerous in nature.

Adolescent↗
PubMed1992

P2 purinergic receptors and cellular calcium metabolism in A 431 human epidermoid carcinoma cells.

Stimulation of P2 purinergic receptors on A 431 human epidermoid cells with ATP rapidly mobilized intracellular calcium and increased cytosolic free Ca2+ ([Ca2+]i). Incorporation of 45Ca2+ was also stimulated by ATP at a rate less than that of [Ca2+]i elevation. Among a number of nucleosides, nucleotides, and their analogues examined, ATP, GTP, UTP, ADP, UDP, adenosine 5'-O-(3-thiotriphosphate) (ATP gamma S), and 5'-adenylylimidodiphosphate (AMP-PNP) increased both [Ca2+]i and 45Ca2+ influx, whereas others did not; these latter two analogues (ATP gamma S and AMP-PNP) blocked the ATP-stimulated 45Ca2+ influx only very slightly, suggesting that they are not prominent antagonists but rather agonists. A high correlation between [Ca2+]i increase and 45Ca2+ influx, in terms of nucleotide specificity, suggests the involvement of [Ca2+]i in influx of 45Ca2+. It appeared that [Ca2+]i elevated by several nucleotides or nucleotide analogues opened a calcium gate, thus allowing the influx of 45Ca2+. P2 purinergic receptors on these cells had such a characteristic that they were rapidly desensitized. These nucleotides or analogues also affected epidermal growth factor (EGF) receptors by inhibiting the EGF binding. The differences of ligand or substrate specificities between P2 purinergic receptors and ecto-nucleotidases indicates that the two components are different molecules involved in different systems.

Calcium↗
PubMed1992

Quantitative analysis on odor intensity and quality of optical isomers in turtle olfactory system.

No systematic electrophysiological study on differences in odor intensity and quality between optical isomers has been carried out. In the present study, we measured the turtle olfactory bulbar responses to six pairs of highly pure optical isomers and compared the differences in odor intensity and quality between the optical isomers. The results obtained indicated that with all odorants tested, there was no difference in odor threshold and intensity in the whole concentration range examined between optical isomers. The difference in odor quality of optical isomers was evaluated by a quantitative cross-adaptation method in which odorant concentration was varied. The degree of cross adaptation between optical isomers greatly varied with species of odorants. The rank order of the magnitude of the differences in odor quality between optical isomers was carvone greater than beta-citronellol greater than menthol greater than hydroxycitronellal greater than citronellal greater than limonene.

Adaptation, Physiological↗
PubMed1992

Characterization of ecto-nucleoside triphosphatase on A-431 human epidermoidal carcinoma cells.

Hydrolysis of extracellular ATP and other nucleoside phosphates by A-431 human epidermoidal carcinoma cells was studied. The hydrolysis of extracellular ATP by these cells required either Mg2+ or Ca2+, and either cation could be replaced by Co2+, Fe2+, or Mn2+. Nucleoside triphosphates (ATP, GTP, CTP, UTP, and dTTP), but not nucleoside diphosphates, were hydrolyzed by the cells with Km and Vmax values similar to those for ATP (0.9-1.1 mmol/l and 6-10 nmol Pi formed/10(6) cells, respectively). The hydrolysis of ATP was inhibited strongly by ATP-gamma S and AMPPNP, and weakly by AMPCPP and ADP-beta S, but not by AMPCPP or AMPCP. Since the hydrolysis of [gamma-32P]ATP was inhibited by all these nucleoside triphosphates, the binding site for ATP is presumed to be the same as that for the other nucleoside triphosphates. All these results indicate that ecto-ATPase activity associated with A-431 cells is due to ecto-nucleoside triphosphatase. The nucleotide specificity shown in the present study indicates that ecto-nucleoside triphosphatase associated with A-431 cells is a molecule different from P2-purinergic receptors which can be stimulated specifically with nucleoside phosphates like ATP, ADP, UTP, UDP, and GTP, but not by other nucleotides.

Adenosine Diphosphate↗