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Biomedical subjects

K Hosoi

Publications and source records attributed to K Hosoi.

At least 37 records · Page 2Linked to original sources
PubMed1998

Salivary gland tissue kallikrein family and processing of growth factor precursors and proenzymes.

Four major enzymes of the tissue kallikrein family were purified from the mouse submandibular gland and characterized. The sequences indicated that they were mK1, mK9, mK13, and mK22. All four enzymes showed kinin-releasing activity, with mK1 exhibiting the highest activity. Like mK13, mK9 and mK22 also processed prorenin to give renin and/or arginyl renin, although their activities were less than that of mK13. The results suggest that tissue kallikrein family enzymes bearing higher kinin-releasing activity have lower prorenin-converting activity and vice versa. These enzymes may possibly have a physiological role in the tissue renin-angiotensin system.

Animals↗
PubMed1997

Serum concentrations of soluble HLA-class I and CD8 forms in patients with viral hepatic disorders.

Soluble HLA-class I and CD8 molecules were determined by sandwich ELISA in patients with viral-induced hepatic disorders. As a whole, the patients with hepatic disorders (acute hepatitis: AH; chronic hepatitis: CH; liver cirrhosis: LC; hepatocellular carcinoma: HCC) showed higher sHLA-class I and sCD8 levels than normal controls (P < 0.001). AH patients had the highest sHLA-class I levels (mean, 3513 +/- 2112 ng/ml), followed by CH (2896 +/- 1290 ng/ml), LC (2293 +/- 1266 ng/ml), and HCC (2221 +/- 1212 ng/ml) sCD8 levels wer highest in AH, followed by HCC, LC, and CH, in that order. Among histologically defined C virus-positive patients, sHLA-I levels were higher in those with chronic active hepatitis (CAH) 2A (3802 +/- 1124 ng/ml) than in those with chronic persistent hepatitis (CPH; 2200 +/- 711 ng/ml; P < 0.01), the levels then decreased as the disease progressed (CAH2B, 3564 +/- 1783 ng/ml, LC, 2376 +/- 1265 ng/ml). In contrast, sCD8 values showed little difference among the disorders. sHLA-class I levels showed a positive correlation with sCD8 values both in whole patients and in patients with AH (P < 0.01), but no correlation was shown, in any patients, with biochemical parameters such as GPT and GOT. These findings, taken together, suggest that hepatic destruction is not the only cause of sHLA-class I production, but that sHLA-class I levels, together with sCD8 levels, may reflect immunological activity in hepatic disorders.

CD8 Antigens↗
PubMed1997

Cryofibrinogenemia with polyarthralgia, Raynaud's phenomenon and acral ulcer in a patient with Graves' disease treated with methimazole.

Cryofibrinogenemia is a cryopathy in which hypersensitivity to cold is a prominent feature. Cryofibrinogenemia developed in an 18-year-old Japanese female patient during methimazole therapy for Graves' disease. She developed cryopathy (livedo reticularis, Raynaud's phenomenon and acral ulcer) and polyarthralgia during methimazole therapy, and we detected cryofibrinogen in her plasma. Her symptoms resolved after administration of prostaglandins and anticoagulants. Several reports indicate that methimazole therapy induces autoantibody-related disease. In the present case, we cannot exclude the possibility that methimazole therapy contributed to the cryofibrinogenemia.

Adolescent↗
PubMed1997

[A case of traumatic extracranial internal carotid artery dissecting aneurysm treated by proximal ligation and STA-MCA bypass].

We present a case with the traumatic extracranial internal carotid artery dissecting aneurysm. A 21-year-old man was involved in a motorcycle accident, resulting in multiple injuries but no apparent head and neck injuries. Head CT was normal on his admission. He was discharged from his local hospital 3 weeks after the accident without any neurological deficits. Five weeks after the accident, he suddenly presented with a motor aphasia and a right hemiparesis. CT and MRI showed infarctions in the left para-Sylvian and the left angular areas. Angiography showed a left extracranial carotid artery dissecting aneurysm at the level of C1 vertebral arch. The patient was initially managed by an anticoagulant agent, but he suffered from another transient ischemic attack due to distal embolism from the aneurysm. Balloon occlusion test of the left ICA was performed under monitoring EEG, SEP. Mean stump pressure (MSP) revealed 60 mmHg. and MSP/Mean systematic blood pressure revealed 67%. We judged that the left ICA ligation was a safe method to treat this patient, however, considering the patient's age and the side of the lesion, left STA-MICA bypass and ligation of the left ICA were carried out in one stage. Postoperatively, the patient did not show any cerebral ischemic complications and angiography showed disappearance of the aneurysm and patency of the bypass. The left MCA territories were filled well by cross circulation and the bypass.

Accidents, Traffic↗
PubMed1996

The rodent granular convoluted tubule cell--an update.

The cells of the granular convoluted tubule (GCT) of the rodent submandibular gland (SMG) are under complex developmental and multihormonal regulation. Recent findings indicate that GCT cells also synthesize transforming growth factor alpha (TGF-alpha), hepatocyte growth factor, erythroid differentiation factor, endothelin, and insulin-like growth factor, as well as several novel androgen-dependent proteins of unknown function. The GCTs of hypophysectomized mice provide a convenient model to study multihormonal regulation of gene expression. The GCT system of the rodent SMG also is a fruitful model for study of hormone receptors.

Animals↗
PubMed1996

ATP- and EGF-stimulated phosphatidulinositol synthesis by two different pathways, phospholipase D and diacylglycerol kinase, in A-431 epidermoid carcinoma cells.

The [(3)H]inositol incorporation into the membrane fraction of A-431 human epidermoid carcinoma cells was markedly increased by stimulation of the cells with either epidermal growth factor (EGF), ATP, bradykinin, or a calcium ionophore A23187 in the presence of 1 mM extracellular calcium ions; most incorporated [(3)H]inositol was found to have accumulated as phosphatidylinositol (PI). The EGF- and ATP-stimulated PI synthesis was inhibited by two protein kinase C inhibitors, staurosporine and 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), and an intracellular calcium chelator, 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA/AM), but not by the calmodulin antagonist N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7). Pretreatment of cells with pertussis toxin (IAP, islet-activating protein) inhibited the PI synthesis, [Ca(2+)]i elevation, and inositol trisphosphate (IP(3)) production by ATP, suggesting that the phospholipase C(PLC) system coupled with IAP-sensitive G protein is involved in the ATP-stimulated PI synthesis. On the other hand, the ATP stimulation increased the release of [(3)H]choline and [(32)P)phosphatidic acid (PA) from radiolabeled cells, and such release was not inhibited by IAP. In the presence of n-butyl alcohol, which prevents the production of PA by generation of phosphatidylbutanol, the ATP-stimulated PI synthesis was reduced. Because n-butyl alcohol did not inhibit IP(3) production and [Ca(2+)]i elevation, this fact suggests that the lAP-insensitive PLD system is involved in the ATP-stimulated PI synthesis. In A-431 cells, the stimulation of P(2)-purinergic receptors appears to activate the IAP-sensitive PLC system and IAP-insensitive PLD system, both of which are essential for the stimulation of PI synthesis. The present results imply the general prospect that ligand stimulation, which mobilizes second messengers and consumes their precursors, simultaneously provokes the pathway to synthesize and salvage the second messenger precursors as well.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1996

Regulation of Na+,K+-ATPase in submandibular glands of hypophysectomized male mice by steroid and thyroid hormones.

The effects of thyroid hormone, androgen, glucocorticoid, and mineralocorticoid on Na+,K+-ATPase activity and on levels of its alpha-subunit protein (alpha 1 isoform) in mouse submandibular gland (SMG) were studied by enzyme assay for ouabain-sensitive ATP hydrolysis, by quantitative densitometric scanning of Western blots, and by immunohistochemistry. To define the specific regulatory effects of various pituitary-dependent hormones on expression of Na+,K+-ATPase in the SMG, we treated hypophysectomized (hypox) male mice with triiodo-L-thyronine (T3), 5 alpha-dihydrotestosterone (DHT), dexamethasone (Dex), and aldosterone (Ald), injected singly or in combination. Na+,K+-ATPase was confined to the duct system of the SMG. In intact mice there was a gender difference in SMG Na+,K+-ATPase, with levels of the enzyme's activity and of its alpha 1-subunit being less in the glands of males. In males, hypophysectomy caused a rise in levels of Na+,K+-ATPase activity and in levels of the alpha 1-subunit protein of this enzyme, and in intensity of immunocytochemical staining for this subunit but there were no such changes in the SMG of hypox females. Changes caused by hormonal replacement to hypox males in Na+,K-ATPase activity, levels of its alpha 1-subunit, or the intensity of immunocytochemical staining for this subunit were complex. Ald had no effect. T3 or dexamethasone, given alone, induced Na+,K+-ATPase activity above control values (hypox males) and increased levels of its alpha 1-subunit protein and immunohistochemical staining for this subunit. By contrast, DHT did not cause a decline in any of these parameters. However, when treatment with T3 was combined with administration of Dex or DHT, enzymatic activity of Na+,K+-ATPase decreased but levels of the alpha 1-subunit protein and immunohistochemical staining for this subunit increased. Therefore, inductions of the alpha 1-subunit of this enzyme are not always correlated with increases in levels of activity of Na+,K+-ATPase, and we propose that both enzymatic and immunochemical analyses are essential for evaluation of hormonal regulation of Na+,K+-ATPase in salivary gland and in other tissues.

Aldosterone↗
PubMed1996

In vivo modulation of proliferating cell nuclear antigen in growth plate chondrocytes from normal, hypophysectomized, growth hormone-treated hypophysectomized rats: a comparative immunohistochemical study with image analysis.

Growth hormone (GH) regulates the proliferation and maturation of chondrocytes in the epiphyseal growth plate, in which a temporal dimension is superimposed on the septal organization of the tissue. In this study we investigated the in vivo effects of hypophysectomy (Hypox) and injection of GH into Hypox animals (Hypox + GH) on the proliferative activity of the growth plate chondrocytes. We assessed the immunohistochemical expression of proliferating cell nuclear antigen (PCNA) in paraffin-embedded tissues, using monoclonal antibody PC 10 against PCNA combined with immunogold-silver staining. We subjected the immunostained sections to computer-based image analysis by ACAS 570 interactive laser cytometry employing a conventional microscopic light source. Hypox was carried out on 20 rats at 8 weeks of age, half of which received a hypodermic injection of human GH at a dose of 1 IU/kg twice a day for 1 week after the operation. Another group of five rats of the same age were used as normal controls. In normal rats, a distinct PCNA immunoreaction was observed in the proliferative zone, whereas a remarkable diminution of the number of immunoreactive cells in this zone was apparent in Hypox animals. On the other hand, marked hyperplasia of PCNA-positive cells was seen in the proliferative zone of the Hypox + GH rat growth plate. The immunoreactive cells of this zone in Hypox + GH animals exhibited increased nuclear size and staining intensity of PCNA compared with those in normal and Hypox rats. These findings were further confirmed by computer-based image analysis of the specimens in terms of cell integrated value, area, perimeter, and shape factor. These different patterns of PCNA expression may imply that GH specifically promotes the proliferation phase of the chondrocytes in the proliferative zone. The data also suggest that GH influences not only cell replication activity but also cell kinetics of chondrocytes in the growth plate during their lifespan.

Animals↗
PubMed1996

A multiple gastric ulcer case caused by cytomegalovirus infection.

The patient was a 31 year old male complaining discomfort in the epigastrium. Endoscopy of the upper gastrointestinal tract indicated multiple gastric ulcers. Biopsy specimen taken from the ulcerous region indicated giant cells accompanying intranuclear inclusion bodies in the gastric mucosa. Since the patient tested positive to cytomegalovirus (CMV)-IgM antibody, he was assumed to have gastric ulcers caused by CMV infection. However, the patient was cured without the administration of antiviral agent because no definite immunodeficiency status was observed. The result of present study indicated that endoscopic biopsy is useful for diagnosing gastrointestinal lesion attributable to CMW infection.

Adult↗
PubMed1995

Extracellular calcium causes the release of calcium from intracellular stores in chick osteocytes.

We have recently demonstrated that a rise in the extracellular divalent cation concentration induces a rapid elevation of cytosolic calcium in chick osteocytes. Here, we demonstrate that cytosolic calcium elevation that occurs in osteocytes on exposure to elevated extracellular calcium is independent of membrane voltage and is insensitive to modulation by organic calcium channel modulators, namely, BAY K 8644, nicardipine, and nifedipine. However, the calcium elevation was sensitive to modulation by an intracellular calcium antagonist, TMB-8, suggesting that the cytosolic calcium elevation was due to mobilization of this cation from an intracellular store.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1995

Effects of FMLP and LPS on [Ca2+]i of peritoneal exudate polymorphonuclear leukocytes following onset of inflammation.

Because a general study of activated neutrophils may have relevance to periodontal diseases and accompanying inflammation, we studied a function of mouse polymorphonuclear leukocytes (PMNs) that exude into the peritoneal cavity in response to inflammation caused by i.p. injection of 2% casein. The effects of E. coli-lipopolysaccharide (E-LPS) and a chemotactic factor, N-formyl-N-methionyl-N-leucyl-L-phenylalanine (FMLP), on the level of intracellular calcium ([Ca2+]i) in these PMNs were examined. From analysis made with a laser cytometer (ACAS 570), the PMNs in exudates harvested 3-9 h after the onset of inflammation were shown to undergo [Ca2+]i elevation in response to 10(-6) M FMLP. The peak concentration of [Ca2+]i elicited by FMLP was highest in exudate cells 6 h after casein injection. In addition, about 65% of the PMNs in the 3-h exudate were FMLP sensitive displaying an elevated [Ca2+]i, whereas more than 85% of them in 6- and 9-h exudates became FMLP sensitive. Also, the maximum level of [Ca2+]i after FMLP stimulation was potentiated by pretreatment of the cells with E-LPS (0.2 microgram/ml). The present study suggests that PMNs induced by casein injection and appearing in mouse peritoneal exudate at different times possess significantly different ability to undergo [Ca2+]i elevation, and different susceptibility toward a chemotactic factor, FMLP.

Animals↗
PubMed1995

Automated measurement of alpha-amylase isoenzymes with 6(3)-deoxymaltotriose as selective amylase inhibitor.

We developed an automated method for measurement of alpha-amylase isoenzymes in serum by a single kinetic assay (SKA) and a double kinetic assay (DKA) with 2-chloro-4-nitrophenyl-6(5)-azido-6(5)-deoxy-beta-maltopentaoside as a substrate and 6(3)-deoxymaltotriose (DOG3) as a novel selective amylase inhibitor. DOG3 showed a large difference in inhibitory activity between human pancreatic alpha-amylase (HPA; 86.9% inhibition) and salivary alpha-amylase (32.1% inhibition) at 0.33 mmol/L. Constant inhibition was obtained immediately after addition of DOG3. The inhibitory effect did not change with variation in concentrations of amylase up to approximately 3000 U/L. The results obtained by SKA correlated well with those obtained by three methods: monoclonal antibody (r = 0.988), wheat germ inhibitor (r = 0.989), and DKA (r = 0.995). The within-run and between-run CVs for HPA were 0.63-2.32% on SKA, 0.69-1.81% on DKA. No significant interferences by endogenous serum compounds were observed with the proposed methods.

Autoanalysis↗
PubMed1994

Computer-aided image analysis applied to immunogold-silver staining: evaluation of proliferating cell nuclear antigen (PCNA)-reactive sites in paraffin sections.

Feasibility of the combination of the immunogold-silver staining method (IGSS) and computer-aided image analysis was assessed for the detection of antigen in an immunostained, paraffin-embedded section. Using low-temperature IGSS, we stained a specimen of human oral squamous cell carcinoma with a monoclonal antibody, PC 10, against a proliferating cell nuclear antigen (PCNA/cyclin), and the section was analyzed by ACAS 570 interactive laser cytometry. The PCNA-positive cells, exhibiting a heteromorphic texture, were contrasted by the dark staining of their nuclei, but showed heterogeneity in staining intensity from cell to cell. Using a conventional microscope light source rather than a laser, and by employing the COMPLEMENT DATA program (which permits inversion of the data values) installed in the ACAS 570 software system, we were able to obtain a 'complemental image' which replicated the real immunohisto-morphology. Approximately 30-35 cells from three different areas in the same section were selected by DEFINE CELL and MARK AREA programs, and quantitative image analysis was performed in terms of cell integrated value, area, perimeter, and shape factor indicated in histogram form. The combined utilization of IGSS with computer-aided image analysis was demonstrated to offer a crucial advantage for the quantitative assessment of immunostained sections.

Humans↗
PubMed1994

Effects of nerve growth factor and dexamethasone on Na+,K(+)-ATPase of cultured PC12h cells.

When PC12h cells were cultured for 4 days in the presence of 50 ng/ml of nerve growth factor (NGF), they showed elongated dendrites and specifically increased Na+,K(+)-ATPase activity. Either singly or in combination with NGF, dexamethasone also increased the specific activity of this enzyme. Western blot analysis using anti-alpha 1 and anti-alpha 2 antisera showed that PC12h cells, either before or after hormone treatment, contained the alpha 1 isoform but not the alpha 2 one. We conclude, therefore, that NGF induces Na+,K(+)-ATPase concomitantly with neuronal differentiation in PC12h cells but that the growth factor does not induce formation of the myelin sheath, which normally expresses the alpha 2 isoform of Na+,K(+)-ATPase.

Animals↗
PubMed1994

Involvement of high-affinity binding site for EGF receptor in formation of rounding in A-431 epidermoid carcinoma cells.

The introduction of a bacterial aminoglycoside phosphotransferase gene (neo gene) into A-431 cells was found to result in disappearance of high-affinity binding sites of the epidermal growth factor receptor (EGFR), probably by affecting the phosphorylation level of the receptors. Using A-431 cells and their neo gene-transfectants, we studied the relation between "rounding" and the high-affinity sites for EGF; and we also examined the role of protein kinase C (PKC) and A (PKA) in the EGF-induced cell rounding. Pretreatment of A-431 and their transfectant cells with 12-O-tetradecanoylphorbol 13-acetate (TPA; 100 ng/ml), an activator of PKC, for 30 min inhibited both the EGF-induced cell rounding and expression of high-affinity binding sites for EGF. However, both of these responses were recovered when cells were pretreated with TPA for 20 h, which treatment is known to result in depletion of PKC by a process called "down regulation". A similar recovery was also observed when cells were pretreated with forskolin (100 microM), an activator of PKA, for 30 min. Both cell rounding and EGFR high-affinity binding sites disappeared by activation of PKC, and reappeared by activation of PKA. These results suggest that the rounding of A-431 cells by EGF was induced via the high-affinity binding sites of EGFR.

Binding Sites↗
PubMed1994

Identification of mK1, a true tissue (glandular) kallikrein of mouse submandibular gland: tissue distribution and a comparison of kinin-releasing activity with other submandibular kallikreins.

The protein structure, kinin-releasing activity, and tissue distribution of four major proteinases of mouse submandibular gland (mK22, mK9, proteinase F, proteinase P) were studied. When compared with the deduced amino acid sequence of each member of the tissue (glandular) kallikrein gene family, the amino acid sequence of proteinase F determined (approximately 40% of the total) was found to agree completely with the deduced amino acid sequence of mKlk-1. The proteinase P sequence, on the other hand, agreed with that of the product of mKlk-13, mK13 (prorenin-converting enzyme). Proteinase F had the strongest kininogenase activity for both low-molecular-weight and high-molecular-weight kininogen, while mK22 had 1/6 and 1/50 the activity of proteinase F for the respective kininogen substrate. Kininogenase activities of mK9 and proteinase P were less than 1/100 of the activity of proteinase F for both substrates. Acting on the two kininogen substrates, kallikreins mK22, mK9, and proteinase F, but not proteinase P, specifically released bradykinin, suggesting that the former three kallikreins strictly recognized peptide sequences around bradykinin in these substrate molecules but proteinase P recognized several sites in these molecules. Significant amounts of proteinase F, but not mK22 and others, were present in the urine, pancreas and digestive organs, as well as in the salivary glands. The present results revealed that the former proteinase F is identical to mK1, tissue/renal kallikrein, and confirmed its characteristics as a true kallikrein on the basis of its kinin-releasing activity and tissue distribution.

Amino Acid Sequence↗
PubMed1994

Comparative phonocardiographic, echocardiographic and Doppler echocardiographic evaluation of normally functioning Medtronic Hall and Björk-Shiley mitral prosthetic valves.

Although data from cardiac catheterization and in vivo studies are available, phonocardiographic and ultrasonic characteristics of the Medtronic Hall valve in the mitral position have not been adequately established. Phonomechanocardiographic, echocardiographic and Doppler echocardiographic examinations were performed in 15 patients (Medtronic Hall group) with a Medtronic Hall mitral valve prosthesis to elucidate the phonocardiographic and ultrasonic characteristics of the normally functioning Medtronic Hall valve in the mitral position. These findings were compared with those obtained from 20 patients (Björk-Shiley group) with a normally functioning Björk-Shiley 60 degrees mitral valve prosthesis. Simultaneous recordings of the phonocardiogram and M-mode echocardiogram of the prosthetic valve in patients in the Medtronic Hall group revealed three opening clicks relating to disc motion. The timing of the three opening clicks correlated with the onset of disc opening, the completion of disc opening, and a notch which appeared about 30 msec after the completion of disc opening. Similar recordings performed in patients in the Björk-Shiley group revealed that the third opening click was detected in only half of the patients and that its timing was nearly twice as early as that noted in the Medtronic Hall group. The Medtronic Hall group had significantly shorter durations of the apical diastolic rumble and the slow filling wave on the apexcardiogram, as well as significantly reduced peak mitral inflow velocity during early diastole and shortened pressure half-time on the mitral inflow velocity curve. Transesophageal Doppler echocardiography demonstrated slight mitral regurgitation in all patients in both the Medtronic Hall and the Björk-Shiley groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗