Biomedical subjects

Y Inoue

Publications and source records attributed to Y Inoue.

At least 1,369 records · Page 76Linked to original sources

PubMed1991

A new rat colon cancer cell line metastasizes spontaneously: biologic characteristics and chemotherapeutic response.

A new cell line (RCN-9) was established in culture from a transplantable rat colon adenocarcinoma, which was induced in the colon of a male Fischer F344 rat by subcutaneous administration of 1,2-dimethylhydrazine. When RCN-9 cells were injected subcutaneously or into the cecal subserosa of syngeneic rats, carcinomas with progressive growth were obtained and the development of lung (63.6%) and liver (40.0%) metastases, respectively, ensued. Antitumor effects of 5-fluorouracil (5-FU), adriamycin (ADM) and mitomycin C (MMC) against RCN-9 were examined in vivo and in vitro. 5-FU and ADM had antitumor effects both in vivo and in vitro; MMC had antitumor effects in vitro. These results show that the RCN-9 cell line can be used both as a model to study mechanisms of metastasis from colon carcinoma and as a model in chemotherapeutic studies of metastatic disease from colon carcinoma.

Adenocarcinoma↗

PubMed1991

Action of mercurials on 3H-cAMP binding to the regulatory subunit-II of cAMP-dependent protein kinase.

Binding of the regulatory subunit type II (RII) of adenosine 3',5'-cyclic monophosphate (cAMP) dependent protein kinase was inhibited by Hg2+ with an IC50 value of 0.31 microM. Methyl mercury, p-chloromercuribenzoic acid (PCMB), and 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) also inhibited cAMP binding with IC50 values of 70-80 microM for organic mercurials and 130 microM for DTNB. Addition of 1 mM 2-mercaptoethanol and 1 M cysteine to the assay mixture reversed these inhibitions. N-ethylmaleimide (NEM) showed little effect on the binding. On the other hand, Hg2+ and methyl mercury markedly suppressed enzymatic activity of the catalytic subunit. The IC50 value was 0.13 microM for Hg2+ and 0.15 microM for organic mercurials. Scatchard plots of kinetic analysis data for the cAMP binding revealed a noncompetitive type of inhibition by mercurials and DTNB. It is suggested that blockade of sulfhydryl groups resulted in the inhibition of cAMP binding to the RII subunit, which might result in preserving the association of the RII subunit and the catalytic subunits and in preventing further inactivation of the catalytic subunit by Hg2+.

Animals↗

PubMed1991

[Isolation trends on group A streptococci isolated from clinical specimens in hospitals in Saitama, 1979-1989].

On 4,864 group A streptococci isolated from throat culture of patients in hospitals in Saitama from 1979 to 1989, we have done an epidemiological analysis of the T-type detection rates and the T-type epidemic, the monthly isolation rates, and the isolation rates by sex and age of patients. 1. The T-type detection rates of 4,864 isolates of group A streptococci showed type T12 in 22.6%, type T4 in 16.4%, type T1 in 10.8%, type T13 in 8.5%, type T6 in 7.6%, type T28 in 6.9%, type T3 in 6.1% and type T18 in 5.3% etc, and the largest number of isolates was type T12 among 16 T-types. 2. The main epidemic T-type during the investigation was type T12, and it was at the top from 1980 to 1981 and from 1984 to 1985. The others, type T4 was at the top from 1982 to 1983 and from 1983 to 1989, type T3 was in 1986, type T6 was in 1987, and type T1 was in 1988, especially it has been suggested that there are the high epidemic T-types and low epidemic T-types among the T-types of throat group A streptococci. 3. Monthly epidemic pattern of throat group A streptococci in each year showed two small epidemic peaks on March and June, a large epidemic peak from November to December since a turn on August. Further, the monthly epidemic pattern has been repeated every year. 4. Throat group A streptococci isolated from patients occupied 87 per cent by the patients from 0 to 14 years, the peak of age distribution showed by age group from 5 to 7 years. The sexual ratio of male to female was in the ratio 1:0.9. Further, the throat group A streptococci isolated from patients of age greater than 15 years was occupied about 50 per cent by age group from 30 to 39 years. A sexual ratio of male to female in the age group was in the ratio 1:1.8.

Adult↗

PubMed1991

Gestational change in Na+ and Ca2+ channel current densities in rat myometrial smooth muscle cells.

The change of Na+ and Ca2+ channel currents during gestation was investigated using the whole cell voltage-clamp method on single smooth muscle cells freshly isolated from the longitudinal layer of pregnant rat uterus. The current-voltage relationships for both the Na+ and Ca2+ currents did not change during gestation. The threshold voltage, the voltage at the peak inward current, and the reversal potential (extrapolated) were virtually identical. The averaged current densities of Ca2+ channel were almost unchanged between days 9 and 21; this value at day 5 was somewhat lower. In contrast, the averaged current density of fast Na+ channels increased markedly in the myometrium during gestation: from 0 at day 5 to 0.19 +/- 0.16 at day 9, to 0.56 +/- 0.13 at day 14, to 0.90 +/- 0.13 at day 18, and to 0.86 +/- 0.14 pA/pF at day 21. This almost linear increase in the averaged density of fast Na+ channels during gestation occurs because of an increase in the fraction of cells which possessed fast Na+ channels. These results suggest that the role of fast Na+ channels in myometrial activity becomes more and more important as term approaches. We suggest that the fast Na+ current may be involved in spread of excitation.

Animals↗

PubMed1991

Regional differences in the sweating responses of older and younger men.

Ten older (60-71 yr) and nine younger (20-25 yr) active healthy men were exposed to passive heating [by placing the lower legs and feet in a 43 degrees C water bath for 60 min while sitting in a warm (35 degrees C, 45% relative humidity) chamber] in summer and winter. The increase in rectal temperature (Tre) was significantly (P less than 0.05) greater, and mean skin temperature and forearm blood flow were lower, for the older men in both seasons. Total sweating rate was lower in the older men, but significantly (P less than 0.05) so only in the summer. The Tre threshold for sweating was unaffected by either age or site (back vs. thigh). The local sweating rate (msw) on the thigh was significantly lower (P less than 0.05) for the older men throughout the exposure, whereas there were no significant age-related differences for the average or peak values of back msw, although lesser sweating on the back occurred during the first 30 min of exposure. The decreased msw on the thigh was due to a lower sweat output per heat-activated sweat gland rather than from recruitment of fewer glands. It was concluded that regional differences exist in the age-related decrement in sweat gland function. Furthermore, these findings suggest that aging leads to a decreased ability to maintain body temperature with passive heating of the extremities, which may be attributed in part to decreased regional sweat gland function.

Adult↗

PubMed1991

Interleukin-6-producing pheochromocytoma.

A 42-year-old female with high fever and headache was admitted. Physical examination revealed hypertension, thrombocytosis with megakaryocytosis, hyperfibrinogenemia, and high level of serum noradrenaline. After operation of extramedullary pheochromocytoma, all symptoms disappeared and findings became normal. The supernatant of tumor culture showed high levels of interleukin-6.

Adrenal Gland Neoplasms↗

PubMed1991

Solitary urethral recurrence of sigmoid colon carcinoma.

We report a rare case of a solitary urethral recurrence of sigmoid colon cancer. The recurrence developed 2 years after a radical resection of sigmoid colon cancer invading the bladder. The involved portion of the urethra was resected and an end-to-end anastomosis was made. The patient has been able to urinate per urethram and has remained free of recurrence for 7 years after the urethral resection.

Adenocarcinoma↗

PubMed1991

Exercise-induced urinary excretion of leukotriene E4 in children with atopic asthma.

Urinary levels of leukotriene (LT) E4, a stable end-product of LTC4 and LTD4, were measured before and after exercise in 10 children with severe asthma and seven children with moderate asthma using HPLC and RIA to clarify the relationship of LT to the severity of asthma and to the degree of bronchospasm in exercise-induced asthma. The urinary LTE4 level significantly increased after exercise in the severe asthma group, but not in the moderate asthma group (14.3 +/- 14.5 to 24.3 +/- 20.6 versus 19.6 +/- 12.3 to 17.6 +/- 10.8 ng/mmol creatinine, p less than 0.05). The urinary LTE4 level increased in 10 patients (eight with severe asthma), and it decreased in seven patients (five with moderate asthma). A significant difference in the degree of bronchospasm after exercise (as shown by the maximal % fall in the peak expiratory flow rate), was seen when patients with increased urinary LTE4 excretion were compared with those with decreased excretion (60.4 +/- 17.3 versus 24.1 +/- 14.3%, p less than 0.01). Our findings suggest that exercise-induced asthma, or at least a subtype of exercise-induced asthma, may partly develop through the release of LTC4.

Asthma, Exercise-Induced↗

PubMed1991

Antibacterial activity of a new tetracyclic quinolone, No. 5290, against norfloxacin- and ciprofloxacin-resistant strains of Staphylococcus aureus.

The antibacterial activity of a new tetracyclic quinolone, No. 5290, against 25 strains of Staphylococcus aureus clinically isolated in Japan in 1988-1989 was determined. The minimum inhibitory concentrations (MICs) of No. 5290 against both quinolone-susceptible (MIC: norfloxacin less than or equal to 6.25 micrograms/ml, ciprofloxacin less than or equal to 1.56 micrograms/ml) and 4 out of 5 norfloxacin- and ciprofloxacin-moderately resistant strains (MIC: 25 micrograms/ml less than or equal to norfloxacin less than or equal to 50 micrograms/ml, 3.13 micrograms/ml less than or equal to ciprofloxacin less than or equal to 12.5 micrograms/ml) were 0.05 micrograms/ml. Similar findings were obtained on the quinolone-resistant mutants derived by norfloxacin- or KB-5246-selection from quinolone-susceptible clinical isolates of S. aureus. The uptake of No. 5290 into a quinolone-susceptible strain of S. aureus was 2.47 micrograms/mg dry cell and the uptake in norfloxacin- and ciprofloxacin-moderately resistant strains was comparable to that in the quinolone-susceptible strain. The uptake of No. 5290 in both the quinolone-susceptible strain, and norfloxacin- and ciprofloxacin-moderately resistant, and No. 5290-susceptible strains was only slightly influenced by the treatment of bacteria with carbonyl cyanide m-chlorophenylhydrazone. These findings indicate that: (i) No. 5290 has potent antibacterial activity against quinolone-susceptible strains of S. aureus, and the potent activity might be due to a high uptake caused by an ineffective efflux of No. 5290. (ii) No. 5290 also has potent antibacterial activity against norfloxacin- and ciprofloxacin-moderately resistant strains, the reason for which could not be explained by the efflux.

Anti-Infective Agents↗

PubMed1991

Novel 1,4-dihydropyridine calcium antagonists. II. Synthesis and antihypertensive activity of 3-[4-(substituted amino)phenylalkyl]ester derivatives.

Novel 1,4-dihydropyridine derivatives bearing 3-[4-(substituted amino)phenylalkyl]ester side chains were prepared and tested for their antihypertensive activity in spontaneously hypertensive rats. Most compounds showed a more potent antihypertensive effect and a longer duration of action than nicardipine. The derivatives with a benzhydrylpiperazinyl and a benzhydrylpiperidinyl group were distinctive. 2-[4-(4-Benzhydryl-1-piperazinyl)phenyl]ethyl methyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate (4e), its 4-(4-cyano-2-pyridyl) analogue (4f), its 3-[4-(4-benzhydryl-1-piperazinyl)phenyl]propyl ester analogue (4h), its 2-[4-(4-benzhydryl-1-piperidinyl)phenyl]ethyl ester analogue (4j), and its 2-[4-(1-benzhydryl-4-piperidinyl)phenyl]ethyl ester analogue (4k) were selected as candidates for further pharmacological investigations.

Animals↗

PubMed1991

[Behavioral pharmacological and electroencephalographic effects of the 5-HT1A partial agonist ipsapirone].

The behavioral and EEG effects of the 5-HT1A partial agonist ipsapirone were investigated to determine its pharmacological characteristics as an anxiolytic drug in rats, mice and rabbits, as compared with those of buspirone and diazepam. 1) The anticonflict effect of ipsapirone was almost equipotent as that of buspirone and less potent than that of diazepam in rats. Ro15-1788 antagonized the anticonflict effect of diazepam, but did not that of ipsapirone. 2) Muricide in midbrain raphe-lesioned and olfactory bulbectomized rats was inhibited by ipsapirone. However, the inhibition of muricide by ipsapirone was attenuated by its repeated administration. 3) The muscle relaxant effects of ipsapirone and buspirone on rotarod performance were less potent than that of diazepam. Ethanol-induced muscle relaxation was markedly potentiated by diazepam, but less potently by ipsapirone and buspirone. 4) The pentetrazol-induced convulsion was dose-dependently antagonized by diazepam, while it was weakly potentiated by ipsapirone and buspirone. 5) The limbic afterdischarges induced by either hippocampal or amygdaloid stimulation in rabbits were markedly inhibited by diazepam. Conversely, ipsapirone and buspirone slightly potentiated afterdischarges. In conclusion, it is suggested that ipsapirone has anxiolytic activities similar to that of buspirone and moderate antimuricidal action. In addition, ipsapirone, like buspirone, is also characterized by its less potent muscle relaxant, alcohol-potentiating and anticonvulsant actions.

Animals↗

PubMed1991

A negative inotropic effect of omega-conotoxin GVIA in isolated, blood-perfused dog right atria.

Using an isolated, blood-perfused canine atrial preparation, we investigated the effects of omega-conotoxin GVIA (omega-CgTX), a blocker of N-type voltage-operated calcium channels, on the atrial contractile force and sinus rate. Omega-CgTX in a dose range of 0.3-3 nmol gradually attenuated the atrial contractile force in a dose-dependent manner, but did not affect the sinus rate, indicating that it can depress contractility but not pacemaker activity.

Animals↗

PubMed1991

Plasma insulin and glucagon and their release from pancreatic islet in hyperosmolar diabetic rat.

In order to investigate the metabolic abnormalities in hyperosmolar diabetes from the viewpoint of insulin or glucagon, experimental hyperosmolar diabetes was produced by a combination of cortisol injection and water deprivation or only by the latter in streptozotocin-induced moderately hyperglycemic rat. They had a high blood glucose level and high plasma osmotic pressure. Fasting plasma insulin tended to decrease in the dehydrated state whether diabetic or not. Fasting plasma glucagon was increased to 0.047 +/- 0.009 nmol/l (P less than 0.05) in the non-diabetic dehydrated state (normal 0.026 +/- 0.004 nmol/l), and a similar high level of plasma glucagon was observed in the dehydrated diabetic rat (0.052 +/- 0.020 nmol/l), especially after cortisol treatment. In isolated rat islet, insulin released from the dehydrated diabetic rat at a high concentration of glucose was to some extent lower than that of diabetic rat, and released IRG vice versa. The insulin:glucagon ratio in the presence of high glucose was significantly lower in the dehydrated diabetic rat than in the normal rat (P less than 0.01). In the diabetic rat this ratio was not significantly different. This finding was also consistent with the results of in vivo experiments. Thus more catabolic hormonal changes were found in in vivo and in vitro studies in the hyperosmolar diabetic rat.

Animals↗

PubMed1991

Effect of a platelet activating factor antagonist and antithrombin III on septicemia and endotoxemia in rats.

Disseminated intravascular coagulation (DIC) or renal damage associated with septicemia was induced in rats by ligating the cecum or by injecting endotoxin. In the septicemia model, the number of E. coli and Bacteroides spp in the blood increased concomitantly with an increase of endotoxin. In this model the development of hypercoagulability with mild fibrinolysis was observed. Histopathologic findings in the kidneys, including the formation of microthrombi in the glomeruli and the vacuolization and dilatation of renal tubular cells, suggest the development of mild DIC. In the endotoxin-induced DIC model, both remarkable state of hypercoagulability and fibrinolysis were observed with fibrin thrombi in glomeruli. The administration of the platelet-activating factor antagonist, CV-6209, or of human antithrombin III, ameliorated DIC significantly by limiting the increases in prothrombin time, activated partial thromboplastin time and fibrin degradation products. These agents significantly reduced the deposition of fibrin in the glomeruli and significantly prolonged the survival time of the endotoxin injected rats. These observations suggest that the PAF antagonist CV-6209 and ATIII merit clinical evaluation in the management of DIC caused by septisemia.

Animals↗

PubMed1991

Postnatal development of the pontine projections from the visual cortex of the mouse.

We studied the postnatal development of the corticopontine tract in mice by the injection of the axon tracer DiI into the visual cortex. In the postnatal day (P) 0.5 mouse, labeled pyramidal tract fibers pass through the internal capsule and cerebral peduncle, grow over the basilar pontine gray, and enter into the medullary pyramid (in this study, P0 refers to the first 24 hours after birth). Small collateral branches arise from these pyramidal tract fibers on P0.5-1.0, and elongate quickly into the basilar pontine gray around P2-4. These collateral branches give off many secondary branches on P4 and form the bright terminal zone in the rostral portion of the lateral basilar pontine gray on P9. In the P16 mouse, this terminal zone is more restricted, suggesting, on the basis of the anterograde DiI labeling technique, that the visual corticopontine projection matures by P16. DiI-labeled pyramidal tract fibers distal to the branching point of the pontine collaterals are found during the postnatal two weeks, but disappear by the later stages. We conclude that the visual corticopontine tract develops as collateral branches of the transient pyramidal tract fibers arising from the visual cortex of the mouse, as just described in the rat (O'Leary and Terashima, Neuron 1:901-910, 1988).

Animals↗

PubMed1991

Preoperative findings and hearing preservation in acoustic neuroma surgery.

For the purpose of clarifying whether or not the possibility of hearing preservation can be predicted preoperatively, we compared clinical characteristics and preoperative test results between hearing preserved and hearing unpreserved patients. Based on an analysis of this study, we conclude that duration of symptoms, ABR findings and caloric test results, in addition to hearing level, speech discrimination score and tumor size should be considered as prognostic signs of hearing preservation. Although all factors do not suggest a definite possibility of hearing preservation, candidates for hearing preservation surgery should be selected according to these prognostic factors.

Adult↗

PubMed1991

Surgical anatomy for the extended middle cranial fossa approach.

The surgical anatomy of the temporal bone and the cerebellopontine angle was studied in cadavers, by performing simulated surgery via the extended middle cranial fossa approach. This approach is classified into 3 types according to extension of the drilling area of the temporal bone. In this paper, the surgical anatomy visualized by the EMCF type II and type III is described. In the EMCF type II, mastoidectomy and labyrinthectomy are performed completely through the middle cranial fossa, and in the EMCF type III permitting hearing preservation surgery, sections of the middle cranial fossa dura and the cerebellar tentorium are added to House's middle cranial fossa approach. The comprehension of these anatomical structures is essential for surgeons in performing acoustic neuroma surgery. We believe that this study will serve to expand our knowledge of surgical anatomy, and that as a result the EMCF approach for acoustic neuroma surgery will become more popular.

Cerebellopontine Angle↗

PubMed1991

Postoperative complications in acoustic neuroma surgery by the extended middle cranial fossa approach.

The complications of acoustic neuroma (AN) surgery by the extended middle cranial fossa approach were studied in 160 cases. Death during surgery occurred in 3 cases (1.9%); 2 of these involved large tumors and the third was a case of recurrence. Transient temporal lobe symptoms were seen in 24 cases (15.3%); the average tumor diameter in these cases was 36.0 mm. Beside symptoms of 7th and 8th nerve disturbance, hemiparesis was seen 7.6%; 3rd, 4th, and 6th cranial nerve symptoms in 7.0%; and cerebellar symptoms in 7.6% of the patients. The incidence of these disturbances increased with tumor size. Cerebrospinal fluid (CSF) leakage occurred in 20.4% of the cases and this necessitated surgical treatment in 5% of the cases.

Cerebral Hemorrhage↗