Search PubMed⌕ Search

Biomedical subjects

T Oishi

Publications and source records attributed to T Oishi.

At least 91 records · Page 5Linked to original sources
PubMed1995

Effect of vasopressin V1- and V2-receptor stimulation on blood pressure in DOCA-salt hypertensive rats.

We recently reported that stimulation of the arginine vasopressin (AVP) V1-receptor enhanced the pressor response in spontaneously hypertensive rats (SHR). In the present study, we investigated acute changes in systolic blood pressure (SBP) and heart rate (HR) after intravenous injections of AVP, OPC-21268 (a V1-receptor antagonist), and OPC-31260 (a V2-receptor antagonist), in anesthetized DOCA-salt hypertensive rats (DOCA) and age-matched sham-operated Wistar rats (control) to determine whether the pressor effect is specific to SHR or is present in other hypertensive animal models. SBP increased significantly in DOCA rats 9 min after injection of AVP 5 ng/kg without a concomitant increase in HR. Neither OPC-21268 3mg/kg nor OPC-31260 3mg/kg caused significant changes in SBP or HR. SBP tended to increase when AVP was administered after injection of OPC-31260. HR increased significantly 15 min after the combined treatment with OPC-31260 and AVP in DOCA rats compared with control rats. SBP did not change significantly when AVP was administered after injection of OPC-21268 in DOCA or control rats, but HR decreased significantly from 1 to 4 min after injection of AVP in DOCA rats. Our results suggest that V1-receptor stimulation does not enhance the pressor response in the DOCA rat, which is a model of volume-dependent hypertension, suggesting that the AVP system, especially V1-receptor, is not as important in the development or maintenance of hypertension in DOCA rats as in SHR.

Animals↗
PubMed1995

Enhanced pressor response in spontaneously hypertensive rats induced by stimulation of vasopressin-V1 receptors.

To elucidate the effect of the arginine vasopressin (AVP) system in vivo, especially V1 and V2 activity, on blood pressure, we measured the acute changes in blood pressure and heart rate after AVP, OPC-21,268 (a V1 receptor antagonist), and OPC-31,260 (a V2 receptor antagonist) were injected intravenously in anesthetized spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats at the age of 15 weeks. Compared with the control period, single injection of AVP 5 ng/kg significantly increased systolic blood pressure in WKY rats without a concomitant increase in heart rate, but there was no significant increase in blood pressure in SHR. In contrast, single injection of either OPC-21,268 3 mg/kg or OPC-31,260 3 mg/kg did not affect blood pressure or heart rate in either SHR or WKY rats. Injection of AVP after the administration of OPC-31,260 induced a greater increase in blood pressure in SHR than in WKY rats, whereas injection of AVP after the administration of OPC-21,268 did not induce any clear increase in blood pressure in SHR or WKY rats. These results suggest that SHR have enhanced pressor activity mediated by V1 receptors and that this increase may be due to an increase in their number. In conclusion, enhancement of V1 activity may contribute to the development of high blood pressure in SHR.

Animals↗
PubMed1995

Crohn's disease associated with growth hormone secretory dysfunction.

A 10-year-old boy presented in 1989 with repeated episodes of vomiting, abdominal distension and severe growth retardation. Endocrinologic examination indicated growth hormone (GH) secretory dysfunction. Administration of recombinant human GH (rhGH) led to growth, but the patient discontinued treatment. He was readmitted to our hospital in 1993, at the age of 16. His stature was very short. Laboratory findings suggested malnutrition. Radiologic examination revealed regional stenosis and a cobblestone appearance of the intestine. The histologic diagnosis was compatible with Crohn's disease. Administration of prednisolone alleviated gastrointestinal symptoms with the improvement of GH secretory function.

Child↗
PubMed1995

Multienzyme control serum (Seraclear-HE) containing human enzymes from established cell lines and other sources. 2: Evaluation as candidate working enzyme Reference Material for alanine and aspartate aminotransferases.

Seraclear-HE, containing seven enzyme analytes from human sources, was evaluated as an intermethod calibrator for aspartate aminotransferase (AST) and alanine aminotransferase (ALT) to transfer Reference Method values to seven routine methods, including one based on hydrogen peroxide detection for possible unification of values (interlaboratory comparability of data). The commutabilities of AST from erythrocytes and ALT from a hepatoma cell line were studied between the consensus methods of Japan Society of Clinical Chemistry (chosen as the Reference Methods) and each of the automated routine methods at reaction temperatures of 30 degrees C and 37 degrees C. For AST, calibration of patients' sera with Seraclear-HE decreased average intermethod variation (CV) from 12% to 2%; for ALT, the decrease was from 20% to 3%. For both enzymes, Seraclear-HE was judged to be commutable between the Reference Methods and each of the methods investigated. The limitations for such use are discussed.

Alanine Transaminase↗
PubMed1995

[Idiopathic acquired generalized anhidrosis with normal numbers of eccrine gland nerve terminals and unmyelinated axons. A case report].

A 37-year-old man with acquired generalized anhidrosis but without other autonomic or somatic abnormalities (idiopathic acquired generalized anhidrosis) is described with special reference to histologic and morphometric findings of the eccrine gland and its nerve terminals and unmyelinated axons. The patient was admitted to our hospital in August 1989 with complaints of heat intolerance and anhidrosis of the face, trunk, and both limbs. General physical and neurological examinations revealed no abnormalities except generalized anhidrosis. Sweating tests revealed anhidrosis of most surfaces of the body except the axillae, mammary areolae, forearms, hands, popliteal fossae, and plantar surfaces. Sympathetic skin responses were absent in the axillae, and were decreased on the palms. Iontophoretically applied pilocarpine revealed a complete absence of active eccrine glands on the dorsal surface of the right foot. No other abnormalities were revealed by autonomic function tests. Light and electron microscopic studies of the eccrine glands of the distal and lateral aspects of the left leg were performed in this patient and six control subjects. Infiltration of mononuclear inflammatory cells around the duct and secretory coil of a limited number of eccrine glands on multiple sections was found only in this patient. Electron microscopic morphometric evaluation of the eccrine glands, associated nerve terminals and unmyelinated axons of this patient revealed no definite alterations when compared with those of the six control subjects. Therefore, we concluded that the nerves innervating the eccrine glands were not affected in this patient and suspect that either the cholinergic receptors or the function of secretory cells of the eccrine glands were involved.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Liposome-mediated DNA transfer into chicken primordial germ cells in vivo.

In embryogenesis, avian primordial germ cells (PGCs) circulate temporarily in the blood vessels at stages 10-15 (Hamburger and Hamilton, 1951), before reaching the gonads. In an attempt to transfer cloned genes into PGCs, liposome consisting of reporter plasmid DNA and N-[1-(2,3-Dioleoyloxy)propyl]-N,N,N-trimethylammoniummethylsulf ate was injected into the marginal veins of embryos at stages 11-15. As reporter plasmids, pRSVZ and pAcZ harboring the Escherichia coli lacZ gene driven, respectively, by the Rous sarcoma virus (RSV) promoter and the chicken beta-actin gene promoter were used. First, 55 embryos were injected with liposome containing pRSVZ and stained for the bacterial beta-galactosidase activity 24 hr after injection. In all the embryos, cells positive for beta-galactosidase activity were observed among the blood cells, endothelial cells, and endocardium cells of the heart, suggesting that transfection took place within the circulatory system. Then, embryos were injected with liposome containing pRSVZ or pAcZ, and stained 2 or 3 d after injection. PGCs positive for beta-galactosidase activity were observed in the gonads in four out of 44 embryos injected with pRSVZ, and 29 out of 71 embryos injected with pAcZ, indicating that the plasmid DNA was transferred into PGCs developing normally. The average number of positive PGCs per embryo was 0.2 and 2.1, respectively, when pRSVZ and pAcZ were introduced. The difference in the number of positive PGCs detected after introduction of the two plasmids suggests that the actin promoter has a higher level of transcriptional activity in PGCs than does the RSV promoter.

Animals↗
PubMed1994

Visual pigments in the pineal complex of the Japanese quail, Japanese grass lizard and bullfrog: immunocytochemistry and HPLC analysis.

We investigated localization of visual pigments in the pineal complex of Japanese quail, Japanese grass lizards and bullfrogs immunocytochemically by use of the antiserum against bovine rhodopsin (Rh-As) and monoclonal antibodies against chicken iodopsin (Io-mAb). We also analyzed retinoids, chromophores of visual pigments, by a high performance liquid chromatography (HPLC). The outer segments and cell membranes of some photoreceptor cells in the pineal organ of the Japanese quail exhibited immunoreactivity to Rh-As, but there are also many immunonegative cells. The number of immunoreactive cells among individuals varied. Immunoreactivity to Io-mAb was weak or did not exist. The HPLC analysis revealed peaks of 11-cis and all-trans isomers of retinal in the oxime extracts of the pineal organ of Japanese quail and chickens. In the pineal of Japanese grass lizards, the outer segments of some cells were immunopositive to Io-mAb, but there were no cells immunoreactive to Rh-As. The parietal eye exhibited a well-developed lens and photoreceptor cells, but the outer segments of photoreceptor cells were immunonegative to both Rh-As and Io-mAb. In bullfrogs, three types of cells were identified in both the pineal and frontal organ; (1) immunopositive to Rh-As, (2) immunopositive to Io-mAb and (3) immunonegative to either of the antibodies. In the pineal organ of bullfrogs, 11-cis and all-trans retinal and 11-cis 3-dehydroretinal were detected, and 11-cis and all-trans retinal were also detected in the frontal organ. We detected 11-cis and all-trans retinal in the ventral part of diencephalon including the hypothalamus. Thus, the chromophore is the same between the retinal and pineal visual pigments, but the expression of opsins is different between the retina and pineal complex, which probably reflects the different function of each organ.

Animals↗
PubMed1994

Immunoreactivities to rhodopsin and rod/cone transducin antisera in the retina, pineal complex and deep brain of the bullfrog, Rana catesbeiana.

Birds and lower vertebrates are known to have extra-retinal photoreceptors in the pineal complex and deep brain. Although the photoreceptive function of the pineal complex has been investigated well, the exact location and nature of the deep brain photoreceptors are not known. In this study we tried to localize visual pigments and signal transduction proteins immunohistochemically in the brain of bullfrogs (Rana catesbeiana). The retina, and the brain with the pineal and the frontal organ were fixed with Zamboni's fixative and/or Bouin's solution. Immunoreactivities to three antisera against bovine rhodopsin (Rh-As), alpha-subunits of bovine rod (anti-pTr alpha) and cone transducin (anti-pTc alpha) were shown in the retina, pineal, frontal organ and hypothalamus. The retina and pineal were immunopositive to both Rh-As and anti-pTr alpha, whereas the frontal organ was immunopositive to only Rh-As and the hypothalamus was immunopositive to all three antisera. The cells which were immunoreactive to Rh-As, anti-pTr alpha and anti-pTc alpha were observed in the preoptic nucleus and suprachiasmatic nucleus in the hypothalamus. The shape of these immunoreactive cells in the hypothalamus was round or spindle-like with one or two immunoreactive nerve processes most of which were perpendicular to the ventricular surface. Western blot analysis of the hypothalamus, pineal and frontal organ demonstrated immunoreactive bands molecular weight of which corresponded to those of the retina (34 kDa, 38 kDa and 41 kDa). Thus, visual pigments and transducin-like proteins seem to exist in the hypothalamus as well as the pineal complex of frogs.

Animals↗
PubMed1994

In vitro micro-autoradiography of atrial natriuretic peptide in biopsy specimens from patients with renal diseases.

We investigated the localization and density of atrial natriuretic peptide (ANP) receptors in human renal biopsy specimens by using in vitro micro-autoradiography (ARG) of [125I]-alpha-human (1-28) ANP. In a preliminary study, we measured the effect of storing tissue samples on ANP binding, using in vitro micro-ARG of Wistar rat kidney under optimal conditions. Duration of the preservation period did not affect ANP binding to renal tissue until samples had been stored at -30 degrees C for two years. A total of 11 human renal tissues were used to assay binding of ANP-ARG, including normal tissue obtained after nephrectomy because of renal cancer. ANP binding occurred predominantly within the glomerulus and, to a lesser extent, in the tubular region both in rat kidney sections and in human renal biopsy specimens. The density of ANP binding, calculated by counting grains in fixed areas, was compared with normal and pathological tissues. The density of grains tended to decrease in patients with renal dysfunction and hypertension except for one case of IgA nephropathy with normal renal function and blood pressure. The density of grains increased in a patient with nephrogenic diabetes insipidus. In the present study, we have established a method that uses in vitro micro-ARG for assessing ANP binding in human biopsy specimens.

Animals↗
PubMed1993

Breeding cycles and fecal gonadal steroids in the brown dipper Cinclus pallasii.

Breeding cycles and fecal gonadal steroids were investigated in free-living brown dippers, Cinclus pallasii. The brown dippers were marked with colored leg bands, and their behavior was observed by a field scope. The breeding season was divided into six stages according to the behavior observed; winter territory-defending, nest-building, copulation, incubation, nestling, and fledgling stages. Fecal pellets on the stones in their territories were collected and the levels of immunoreactive estradiol-17 beta (E2) and testosterone (T) in 10 mg feces were measured by radioimmunoassay. Levels of fecal E2 were high only during the copulation stage, which lasted for a few weeks, in all females of the three pairs observed. In contrast, T levels in the feces of males increased in late winter when intensive territory-defending behavior was observed, and remained high until the end of the breeding season. T levels during the nest-building stage and the copulation stage were similar to those during other nesting stages. When the birds breed only once a year, the duration of high levels of T was shorter than that of the pair with the second clutch. T levels in the feces of females showed a similar pattern to E2 levels.

Animals↗
PubMed1993

Sulfhydryl drugs reduce neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in the mouse.

Striatal levels of dopamine and its metabolites 3-methoxy-4-hydroxy-phenylacetic acid (DOPAC) and homovanillic acid (HVA) decreased 7 days after subcutaneous injection of MPTP (20 mg/kg) to the mouse. Striatal GSH contents decreased and GSSG/GSH ratios increased one hour after subcutaneous administration of MPTP. Pretreatments of both cysteamine (200 mg/kg, s.c.) and dimercaprol (20 mg/kg, i.m.) reduced the MPTP-induced decreases in striatal dopamine, DOPAC and HVA, and also prevented the MPTP-induced decreases in GSH levels and increases in GSSG/GSH ratios. On the other hand, injection of cysteamine did not modify the MPTP-induced decreases in striatal levels of dopamine and its metabolites when it was done 2 hours after MPTP administration. Moreover, pretreatment of cysteamine did not affect striatal concentrations of MPP+ in MPTP-treated mice. These results suggest that sulfhydryl drugs such as cysteamine and dimercaprol may reduce neurotoxicity of MPTP probably via changes in redox cycle of glutathione in the brain.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1993

Neurological manifestations of hemorrhagic colitis in the outbreak of Escherichia coli O157:H7 infection in Japan.

An outbreak of hemorrhagic colitis associated with Escherichia coli O157:H7 occurred in a kindergarten in Saitama, Japan from September to November, 1990. Seven patients admitted to our hospital showed neurological manifestations: generalized seizures, impaired consciousness, urinary incontinence, gaze nystagmus, phrenic nerve palsy, action tremor and vertigo. Two patients died. On the basis of the clinical courses and laboratory findings of the seven patients and postmortem findings of one case, these neurological symptoms were suspected to be induced by the verotoxin elaborated by Escherichia coli O157:H7.

Bacterial Toxins↗
PubMed1993

[Alveolar epithelial permeability in bronchial asthma in children. An evaluation by 99mTc-DTPA inhalation scintigraphy].

To evaluate alveolar epithelial permeability (kep) in children with bronchial asthma, 99mTc-DTPA (diethylene triamine penta acetate) aerosol lung inhalation scintigraphies were performed. There was no correlation between the kep value and the severity of asthma. On the other hand, out of 10 the cases which had no aerosol deposition defect in the lung field, 4 showed high kep values on the whole lung field and 7 had high kep value areas, particularly apparent in the upper lung field. These results suggest that even when the central airway lesions are mild, severe damage exists in the alveolar region of the peripheral airway.

Administration, Inhalation↗
PubMed1993

[Assessment of myocardial perfusion and left ventricular function with 99mTc-PPN 1011].

First-pass radionuclide angiography (FPRNA) was performed with the new myocardial perfusion agent 99mTc-1,2,bis[bis(2-ethoxyethyl)phosphino] ethane (99mTc-PPN 1011) on stress and at rest. One hour after that, myocardial perfusion was counted by 99mTc-PPN 1011 SPECT. Left ventricular ejection fraction (LVEF) obtained by FPRNA correlated with that by multigated image with 99mTc-HSAD (r = 0.94, n = 11). The reduction of left ventricular function under the exercise (delta LVEF) and the increase of severity score (delta Severity score) have a good relation (r = 0.88) in 7 patients with prior myocardial infarction. Thus 99mTc-PPN 1011 appears to be an ideal radiopharmaceutical for evaluation of ventricular function and myocardial perfusion.

Aged↗
PubMed1993

[Acute cerebellar ataxia with sympathotonic orthostatic hypotension following Epstein-Barr virus infection--a case report].

A 21-year-old man with acute cerebellar ataxia and sympathotonic orthostatic hypotension, following Epstein-Barr (EB) virus infection, was reported. He noticed unsteady gait 2 weeks after the development of cough, nausea and vomiting. On admission, he was unable to sit and walk due to truncal ataxia and orthostatic hypotension with marked tachycardia. Limb ataxia of moderate degree was also noted. The blood pressure was 112/42 mmHg, and the pulse rate was 64/min in supine position, and 5 minutes after standing, they were 82/42 mmHg and 128/min. In laboratory studies, no atypical lymphocytes were detected in the peripheral blood. However, the titers of antibodies, VCA-IgM, against EB virus, were x80 and x160 in serum, respectively. And the titer of VCA-IgM subsequently decreased to the normal level in two months. They were negative in the cerebrospinal fluid. The results of the autonomic function studies revealed dysfunctions of the sympathetic post-ganglionic nerves, especially of alpha-adrenergic system, with preservation of beta-adrenergic system. He recovered from cerebellar ataxia and from sympathotonic orthostatic hypotension 3 and 8 months after the onset, respectively, without residuals.

Acute Disease↗
PubMed1993

[A new sequential chemotherapy of methotrexate with 5-fluorouracil against advanced colo-rectal cancer].

A new sequential chemotherapy consisting of intravenous (IV) administration of methotrexate (MTX) 50 mg/m2 followed by 3 equal IV doses of 5-fluorouracil (5-FU) 500 mg/m2 at 1.4 and 21 hrs. and a leucovorin rescue (15 mg/body/8 hr) from 24 hrs. after MTX for 3 days was applied every two weeks for the patients with advanced colo-rectal cancer. The effectiveness of this MTX/3-dose 5-FU regimen was compared retrospectively with that of the standard sequential regimen consisting of the IV administration of MTX 100 mg/m2 followed by a single IV dose of 5-FU 800 mg/m2 one hr. later and a leucovorin rescue (21 mg/body/6 hr) 24 hrs. later given every week, namely MTX/1-dose 5-FU regimen. Partial response was achieved in 7 (46.7%) of 15 evaluable patients with the MTX/3-dose 5-FU regimen and in 3 (13.6%) of 22 evaluable patients with the MTX/1-dose 5-FU regimen (p < 0.05). The median survival times were 13 and 9 months, respectively. There were no significant difference in the patient characteristics between the two groups, and the toxic effects were much lower in the MTX/3-dose 5-FU than in the MTX/1-dose 5-FU regimen. It is therefore, concluded that the MTX/3-dose 5-FU regimen is superior to the standard MTX/1-dose 5-FU regimen.

Adult↗
PubMed1993

[Semi-quantitative evaluation of cerebral blood flow with modified bull's eye display using 123I-IMP SPECT].

We developed Modified Bull's Eye (MBE) display to demonstrate 123I-IMP SPECT images on a single map. To compare the difference of some SPECT images, we changed the ratio of the occipitofrontal diameter to the temporal diameter of oblique SPECT images and transformed the oblique images to round-shaped images. After circumferential profile analysis (CPA) was performed on the round-shaped oblique images, the data were mapped into a polar representation (MBE display). The severity score, as the index of severity of the perfusion defect, was calculated in the same way as the myocardial SPECT. We selected five slices from the round-shaped SPECT images and divided each slice into 12 areas. The severity of the perfusion defect was scored (0-3 points) visually, and the total score was defined as the "severity points". We compared the severity score with the severity points for 29 patients and six normal male volunteers. The correlation coefficient of the severity score and the severity points was 0.86 (p < 0.001). The MBE display makes it easy to evaluate SPECT images because it is represented on a single map, and it takes no more time to construct than the myocardial bull's eye display. It should be useful display.

Adult↗