Biomedical subjects

T Takeuchi

Publications and source records attributed to T Takeuchi.

At least 631 records · Page 35Linked to original sources

PubMed1996

Renal primitive neuroectodermal tumor: an immunohistochemical and cytogenetic analysis.

The cytogenetic and morphologic characteristics of a case with a primitive neuroectodermal tumor (PNET) arising from the left kidney in a 22 year old man are presented. The patient was detected as having a left renal mass with a tumor embolus in the inferior vena cava and multiple pulmonary metastases. A radical nephrectomy with tumor embolectomy of the inferior vena cava, along with a resection of the pulmonary nodules were performed. Histologic examination revealed a dense proliferation of small round cells with many Homer-Wright type rosettes and perivascular pseudorosettes. Immunohistochemically, the tumor cells stained strongly positive for HBA71(p30/32MIC2), a surface glycoprotein specific to PNET and Ewing's sarcoma. In addition, the tumor cells expressed several neural markers (neuron specific enolase, neurofilament, synaptophysin, and Leu-7) and vimentin, while the epithelial, muscular, and lymphocytic markers were negative in the tumor cells. Cytogenetic analysis of cultured tumor cells showed a reciprocal translocation t(11;22)(q24;q12) that is considered to be specific to PNET and Ewing's sarcoma. In conclusion, this case suggested that a karyotyping analysis is a useful diagnostic tool for renal PNET, and it may therefore be utilized to help distinguish between difficult cases of small round cell tumors and Wilms' tumor of the kidney.

Adult↗

PubMed1996

Strangulated prolapsed ureterocele: a solid vulval mass in a woman.

We report a rare case of prolapsed ureterocele in an adult female, which had been identified as a small finger-tip sized orthotopic ureterocele 12 years earlier and recently presented a hard neoplastic mass due to strangulation at the urethra and long-standing inflammation.

Adult↗

PubMed1996

VIP- and PACAP-mediated nonadrenergic, noncholinergic inhibition in longitudinal muscle of rat distal colon: involvement of activation of charybdotoxin- and apamin-sensitive K+ channels.

1. The mediators of nonadrenergic, noncholinergic (NANC) inhibitory responses in longitudinal muscle of rat distal colon were studied. 2. An antagonist of pituitary adenylate cyclase activating peptide (PACAP) receptors, PACAP6-38, concentration-dependently inhibited the rapid relaxation of the longitudinal muscle induced by electrical field stimulation (EFS), resulting in a maximal inhibition of 47% at 3 microM. 3. PACAP6-38 inhibited the relaxation by 75% in the presence of the vasoactive intestinal peptide (VIP) receptor antagonist, VIP10-28 at 3 microM, which inhibited the relaxation by 44%. 4. An antagonist of large conductance Ca(2+)-activated K+ channels, charybdotoxin, concentration-dependently inhibited the rapid relaxation of the longitudinal muscle, resulting in a maximal inhibition of 58% at 100 nM. 5. An antagonist of small conductance Ca(2+)-activated K+ channels, apamin, concentration-dependently inhibited the relaxation (58% at 1 microM). 6. Treatment with both K+ channel antagonists resulted in 84% inhibition of the EFS-induced relaxation, which is comparable to the extent of inhibition induced by PACAP6-38 plus VIP10-28. 7. The inhibitory effect of VIP10-28 and of apamin, but not of charybdotoxin was additive: the same applied to PACAP6-38 and charybdotoxin, but not apamin. 8. Exogenously added VIP (100 nM 1 microM) induced a slow gradual relaxation of the longitudinal muscle. Charybdotoxin, but not apamin significantly inhibited the VIP-induced relaxation VIP10-28, but not PACAP6-38 selectively inhibited the VIP-induced relaxation. 9. Exogenously added PACAP (10-100 nM) also induced slow relaxation. Apamin and to a lesser extent, charybdotoxin, inhibited the PACAP-induced relaxation. PACAP6-38, but not VIP10-28 selectively inhibited the PACAP-induced relaxation. 10. Apamin at 100 nM inhibited inhibitory junction potentials (i.j.ps) induced by a single pulse of EFS Apamin also inhibited a rapid phase, but not a delayed phase of i.j.ps induced by two pulses at 10 Hz. VIP10-28 did not inhibit i.j.ps induced by a single pulse, but significantly inhibited the delayed phase at two pulses. A combination of apamin and VIP10-28 abolished the i.j.ps induced by two pulses. 11. Both VIP and PACAP induced slow hyperpolarization of the cell membrane of the longitudinal muscle. Apamin inhibited the PACAP-, but not VIP-induced hyperpolarization. 12. From these findings it is suggested that VIP and PACAP are involved in NANC inhibitory responses of longitudinal muscle of the rat distal colon via activation of charybdotoxin- and apamin-sensitive K+ channels, respectively.

Animals↗

PubMed1996

Nitric oxide-mediated relaxation without concomitant changes in cyclic GMP content of rat proximal colon.

1. We studied the relation of nitric oxide-mediated relaxation of longitudinal muscle to changes in cyclic GMP content of the tissue in the proximal colon of rats. 2. Dimethylphenylpiperazinium (DMPP) and electrical field stimulation (EFS) induced nitric oxide-mediated relaxation of the segments with a concomitant increase in cyclic GMP content. 3. LY 83583 and methylene blue, soluble guanylyl cyclase inhibitors, significantly inhibited the stimulatory effects of DMPP and EFS on the cyclic GMP content, but did not affect the relaxant responses of the segments to DMPP and EFS. 4. Rp-8 bromo cyclic GMPS, an inhibitor of cyclic GMP-dependent protein kinase had no effect on DMPP- and EFS-induced relaxation. 5. These data strongly suggested that nitric oxide-mediated relaxation of the rat proximal colon is not associated with change in cyclic GMP content of the tissue.

Aminoquinolines↗

PubMed1996

8-methoxypsoralen and ultraviolet a radiation activate the human elastin promoter in transgenic mice: in vivo and in vitro evidence for gene induction.

Treatment of skin diseases with the combination of 8-methoxypsoralen and ultraviolet A radiation (PUVA) results in clinical alterations in treated skin that resemble those observed in chronically photodamaged skin. The PUVA-treated patients develop nonmelanoma skin cancers, pigmentary alterations and wrinkling characteristic of sun-induced changes. The major alteration in the dermis of sun-damaged skin is the deposition of abnormal elastic fibers, termed solar elastosis. Up-regulation of elastin promoter activity in dermal fibroblasts explains the excess elastic tissue but not the reason for the aberrant morphology of the elastotic material. In order to study photoaging in an experimental system, we utilized a transgenic mouse line that expresses the human elastin promoter/chloramphenicol acetyltransferase construct in a tissue-specific and developmentally regulated manner. Although UVB radiation has been demonstrated to increase promoter activity in vitro, UVA fails to demonstrate a similar effect at the doses utilized. In this study, we demonstrate the ability of PUVA treatment to up-regulate elastin promoter activity both in vitro and in vivo. These data help to explain the development of photoaging in sun-protected PUVA-treated skin. We attribute the up-regulation of elastin promoter activity in response to PUVA to the formation of DNA photoadducts, which do not occur in response to UVA radiation alone.

Animals↗

PubMed1996

Bile secretion in rats with indomethacin-induced intestinal inflammation.

The objective of this study was to characterize the bile secretion, including the composition of biliary bile acids, bile salt pool size, and transcytotic vesicle transport, in a rat model of subacute intestinal inflammation induced by indomethacin. Indomethacin treatment significantly decreased bile acid-independent bile flow and biliary secretion of bile acid and cholesterol, while increasing biliary phospholipid output in vivo. Although indomethacin treatment did not change the bile salt pool size in vivo, alpha- and beta-muricholic acids were significantly deceased and hyodeoxycholic and deoxycholic acids were increased in bile. Bile flow and the transport maximum of taurocholate did not decrease, and biliary horseradish peroxidase output was significantly enhanced in isolated perfused livers from indomethacin-treated rats. Endotoxin in the portal blood was significantly increased in rats treated with indomethacin. Clindamycin slightly reduced intestinal inflammation but significantly prevented decreases in bile flow, bile acid output, and transport maximum of taurocholate. We conclude that, although biliary secretory function was apparently decreased in vivo, that of hepatocyte function was maintained in this model.

Animals↗

PubMed1996

Assignment of the gene for rat thromboxane receptor (Tbxa2r) to chromosome 7q11 by fluorescence in situ hybridization.

Thromboxane plays physiological and pathophysiological roles in many tissues. Recently, we cloned a cDNA for rat kidney thromboxane receptor (Tbxa2r) and showed that Tbxa2r is expressed in the renal glomerulus, vasculature, and transitional cell epithelium of renal pelvis. Here, we map the gene for this receptor (Tbxa2r) to rat chromosome 7q11 by fluorescence in situ hybridization.

Animals↗

PubMed1996

Interleukin-4 and IgE in seasonal allergic conjunctivitis.

We measured interleukin-4 (IL-4) and IgE to study their presence in patients with seasonal allergic conjunctivitis. Twenty patients and 10 normal subjects were enrolled in this study, and their brush cytology samples and peripheral blood lymphocytes (PBL) were cultured for 3 or 24 h. IL-4 levels were measured using ELISA in the supernatants. Measurements of serum IgE were also performed. IL-4 was detected in 4 of 40 brush cytology samples and 10 of 40 PBL samples, but not from the controls. IL-4 positivity rate of patients was significantly higher than normal in 24-hour cultured PBL (p = 0.03). Patients' serum IgE was also significantly higher (p = 0.006). IL-4 may contribute to the development of seasonal allergic conjunctivitis.

Adolescent↗

PubMed1996

Developmental expression of proprotein-processing endoprotease furin in rat pancreatic islets.

The expression of furin in pancreatic beta-cells induces faster cell growth and a decrease in differentiated beta-cell-specific characteristics. During the development of rat pancreatic islets, the prohormone convertases, PC2 and PC3, appear during late gestation and are expressed long after birth. We investigated the developmental change in another yeast Kex2 family endoprotease, furin, in rat islets in relation to islet cell growth. Furin had appeared by gestational day 18 and was distributed in islets as well as exocrine tissues. The expression of furin in islets increased toward the neonatal stage. Bromodeoxyuridine (BrdU) incorporation was also elevated in the perinatal period. On postnatal days 10 and 20, staining characteristics were attenuated. On day 25, immediately after weaning, furin staining began to localize in the beta-cell region, and staining in the alpha-cell region became fainter. On day 270, the staining in the alpha-cell region disappeared, and staining in the beta-cell region remained positive, but was weaker. We conclude that furin expression was greatest during the perinatal period, when BrdU incorporation into islets was maximal. Furin expression continued, however, even after the BrdU incorporation decreased. Thus, furin appears to control the proliferation as well as differentiation of islet cells.

Aging↗

PubMed1996

Discrete characteristics of antibodies raised against thyrotropin receptor-related peptides whose sequences are not conserved in the luteinizing hormone/chorionic gonadotropin receptor.

In order to identify the specific regions in the human TSH receptor for TSAb and thyroid stimulation-blocking antibody (TSBAb), we produced rabbit antibodies raised against several peptides of the extracellular domain of the human TSH receptor, where sequences are not conserved in the LH/CG receptor, and measured the TSAb activity and TSBAb activity of those antibodies using Chinese hamster ovary cells expressing human TSH receptors. Only antisera from rabbits that were immunized with a peptide of amino acid 32-56, including the small insertion near the N-terminal end of the extracellular domain, showed apparent TSAb activities and have been shown to be significantly precipitated by IgG of patients with Graves' disease. TSAb activity positively correlated with the antibody titers against the peptide in those rabbits. In contrast, antisera from rabbits immunized with a peptide of amino acid 352-378, including a part of the large insertion near the C-terminal end of the extracellular domain, showed the obvious TSBAb activities. TSBAb activity also positively correlated with the degree of antibody titers against the peptide in those rabbits. Moreover, this peptide was significantly immunoprecipitated by the IgG from hypothyroid patients who had TSBAb, and the immunoprecipitation of this peptide positively correlated with TSBAb activities. These results suggest that the epitope responsible for TSAb is quite different from that for TSBAb in the extracellular domain of the human TSH receptor.

Amino Acid Sequence↗

PubMed1996

Frequency, significance, and mechanism of myocardial ischemia during daily activities detected by Holter dynamic electrocardiogram.

Exercise testing (EX) and Holter ECG (DCG) were performed consecutively in 52 patients with ischemic heart disease. A total of 100 episodes of myocardial ischemia (IE) were recorded during DCG in 30 patients, who constituted 94% of the patients with myocardial ischemia under 6 metabolic equivalents (METs) during EX. A significant increase in heart rate (HR) was observed before the development of IE. The duration of this increase in HR was longer in IE than in periods in which the HR increased above the ischemic threshold, but without ischemia. The incidence of IE showed two peaks at 8-10 am and 4-6 pm. The frequency of IE among all of the periods with increased HR was highest at 8-10 am (51%). IE in the morning was associated with a lower HR than that in the afternoon, and LF/HF, which reflects sympathetic activity, evaluated using power spectral analysis, increased before IE in the morning. The early appearance of myocardial ischemia in EX can predict its appearance in daily life. The increase in HR and its duration appear to be associated with the development of IE. The increases in sympathetic activity in the morning and the increase in myocardial oxygen demand accompanied by physical activity in the afternoon most likely contributed to the circadian variation in the incidence of ischemic episodes.

Activities of Daily Living↗

PubMed1996

Cooperation of ATP and norepinephrine in inducing contraction in guinea pig vas deferens is not associated with change in intracellular Ca2+ level.

Contractile responses and fura-2 fluorescence signals were simultaneously recorded in fura-2 loaded longitudinal muscle strips of guinea pig vas deferens to examine the relationship between cooperation of ATP and norepinephrine (NE) in the contractile response and intracellular Ca2+ level. ATP or NE induced a rapid or delayed contraction, respectively, with concomitant changes in fura-2 signal. Addition of both agonists potentiated the rapid, but not delayed contraction, while there was no potentiation in the fura-2 signal. In another series of experiments, NE (> or = 10 microM) contracted the muscle without further concomitant increase in Ca2+ level, indicating "Ca2+ sensitization" of the contractile apparatus. These findings suggest that cooperation of ATP and NE in inducing a rapid contraction of guinea pig vas deferens is mainly due to the "Ca2+ sensitization" effect of NE.

Adenosine Triphosphate↗

PubMed1996

8-Hydroxydeoxyguanosine in human leukocyte DNA and daily health practice factors: effects of individual alcohol sensitivity.

A typical oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OHdG), was evaluated in human polymorphonuclear leukocytes (PMN) and mononuclear leukocytes (MN) by an anaerobic determination method. The mean 8-OHdG values were the lowest level ever reported [PMN, 3.07 +/- 1.45; MN, 2.37 +/- 1.21 8-OHdG/10(6) deoxyguanosine molecules (dG); n = 92]. According to a self-administered questionnaire to 92 healthy male workers, the relationship was investigated between 8-OHdG in leukocytes and daily health practice factors, that is, the frequency of physical exercise, smoking status, alcohol drinking, nutritional balance, and the degree of mental stress. A significant difference was observed only in alcohol drinking in subjects classified by aldehyde-dehydrogenase 2 isozyme (ALDH2) genotype. Habitual alcohol intake appeared to increase 8-OHdG in PMN from ALDH2-deficient subjects. Neither age, body mass index, nor any other factors examined showed any significant correlation with the 8-OHdG levels in leukocytes.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed1996

Ludloff's medial approach for open reduction of congenital dislocation of the hip. A 20-year follow-up.

We reviewed 33 patients (35 hips) after open reduction of congenital dislocation of the hip using Ludloff's medial approach. The mean age at the time of operation was 14 months (5 to 29) and at the time of final follow-up 20.1 years (15 to 24) giving a mean duration of follow-up of 19.4 years (14 to 23). We evaluated the radiological results by the Severin classification and the extent of avascular necrosis using the criteria of Kalamchi. At the latest review 16 hips (45.7%) were in Severin groups I or II (acceptable results) and 19 (54.3%) in Severin groups III, IV or V (unacceptable results). There was evidence of avascular necrosis in 15 hips (42.9%). The radiological results began to become worse at about the age of ten years when type-II avascular changes presented. We conclude that Ludloff's medial approach for open reduction is unsatisfactory for the treatment of congenital dislocation since about half of our patients required additional operations.

Child, Preschool↗

PubMed1996

Two distinct signaling pathways activated by activin A in glucose-responsive pancreatic beta-cell lines.

Activin A stimulates insulin secretion in pancreatic beta-cells by a calcium-dependent mechanism. The present study was conducted to further characterize the effects of activin A in two glucose-responsive insulinoma cell lines, MIN6 and HIT-T15 cells. In HIT-T15 cells, activin A evoked an increase in cytoplasmic free calcium concentration, stimulated insulin secretion, maintained glucose responsiveness of the cells and inhibited DNA synthesis. However, activin A did not have any effect in MIN6 cells. Measurement of 125I-labeled activin A binding in MIN6 cells revealed that the number of binding sites was markedly reduced, suggesting that the refractoriness was due, at least partly, to the reduced numbers of the activin receptor. Stable transfectants of MIN6 cells that overexpressed the type II activin receptor were then developed. The transfected cells (MIN6-ActR cells) expressed ten times more 125I-labeled activin A-binding sites than parental cells and the apparent Kd was 1.15 nM, which was nearly identical to that in parental cells. Affinity cross-linking in MIN6-ActR cells showed that a 90 kDa type II receptor as well as a 52 kDa protein, presumably follistatin, was markedly labeled with 125I-labeled activin A. Although MIN6-ActR cells expressed significant numbers of activin receptors, activin A did not induce immediate calcium-dependent responses in these cells. In contrast, activin A was capable of inducing long-term effects in MIN6-ActR cells; thus, reduction of the glucose concentration in culture medium from 25 to 5.5 mM for 4 days resulted in a remarkable loss of insulin response to glucose stimulation but this decline in response to glucose was prevented by the addition of activin A during culture. In addition, activin A inhibited DNA synthesis in MIN6-ActR cells. Hence, although activin A did not induce calcium-dependent responses, it evoked some calcium-independent effects in MIN6-ActR cells. Taken together, activin A elicits various effects in beta-cells by both calcium-dependent and -independent mechanisms.

Activin Receptors↗

PubMed1996

Total obliteration of colonic lumen by localized giant inflammatory polyposis in ulcerative colitis: report of a Japanese case.

Although inflammatory polyposis of the colon is a recognized local complication of ulcerative colitis, giant inflammatory polyposis that totally obliterates the colonic lumen is uncommon, and most of the patients have been from Western countries. We report a Japanese man who had localized giant inflammatory polyposis that obstructed the retrograde flow of barium in a double-contrast barium enema study at the splenic flexure in ulcerative colitis. After resection by total proctocolectomy and ileostomy, pathological examination of the specimen confirmed localized giant inflammatory polyposis in the descending colon and spelnic flexure without malignancy.

Barium Sulfate↗

PubMed1996

Cystplastic cyst-subarachnoid shunt procedure for arachnoid cyst of the middle cranial fossa--technical note.

A cystplastic cyst-subarachnoid shunt procedure using a ventricular catheter of Denver type shunt system was performed in seven patients with non-communicating middle cranial fossa arachnoid cyst. The operation technique consists of: linear incision of the outer membrane of arachnoid cyst and intrusion into the cyst; followed by a 5 mm incision of both the inner membrane of the arachnoid cyst and the arachnoid membrane; insertion of a 2-3 cm length of the ventricular catheter, cut as required with silk thread bound around the midpoint of the tube, into the subarachnoid space; fixation of the tube to the arachnoid membrane by a silk thread with Weck clips; and finally suturing of the outer membrane of arachnoid cyst by a nylon thread. During the follow-up period of 3 months to 3 years after the operation, the symptoms were relieved in all patients, and no recurrence or complication was observed.

Adolescent↗

PubMed1996

Measurement of interleukin-4 and histamine in superficial cells of conjunctiva in patients with allergic conjunctivitis.

Interleukin 4 (IL-4) may play a role in the development of allergic disease. We questioned whether IL-4 related phenomenon occurred on the surface of the conjunctiva during allergic conjunctivitis. Ten patients with cedar pollen-allergic conjunctivitis and 10 patients with postsurgical conjunctivitis were enrolled in this study. Cells were collected by brush cytology from the upper palpebral conjunctiva. After the cells were cultured for 24 hours, the levels of IL-4, IgE, and histamine were measured in the supernatants. An ELISA was used for histamine and a highly sensitive sandwich ELISA for IL-4 and IgE. Conjunctival cells were also stained and fixed by May-Grunwalds stain solution. The number of superficial cells, especially lymphocytes, were compared in the two groups. The total number of cells collected by brush cytology did not differ in allergic vs., postsurgical conjunctivitis. Lymphocytes were similarly present in such specimens. The levels of IL-4 (p = 0.01) and histamine (p = 0.02) significantly increased in the specimens from patients with allergic conjunctivitis, although IgE was not detected in both groups. There was a correlation between the level of IL-4 and histamine (p = 0.0001). Conjunctival cells in allergic conjunctivitis produced a larger amount of IL-4 and histamine for cedar pollen compared to the postsurgical conjunctivitis. As with other allergic diseases, IL-4 may play a role similar to that of histamine in the development of allergic conjunctivitis.

Adolescent↗