Biomedical subjects

S Takano

Publications and source records attributed to S Takano.

At least 19 recordsLinked to original sources

PubMed1992

Isolation and identification of C-type natriuretic peptide in human monocytic cell line, THP-1.

In a survey for unknown bioactive peptides in mammalian cell lines, we isolated peptides exhibiting a strong relaxant effect on chick rectum from a phorbol ester-supplemented culture medium of the human monocytic cell line, THP-1. The peptide was deduced to be a C-terminal 29-residue peptide derived from a human C-type natriuretic peptide (CNP) precursor. CNP mRNA was also detected in the THP-1 cells, and expression of CNP gene and CNP concentration in the culture medium was found to be highly augmented by the stimulation of phorbol ester. Production of CNP in THP-1 cells suggests that CNP also functions as a local regulator in the blood cell-vascular system, although CNP has previously been recognized as a neuropeptide functioning in the central nervous system.

Amino Acid Sequence↗

PubMed1992

Activation of paraventricular neurosecretory cells by local osmotic stimulation of the median preoptic nucleus.

Both electrical and local osmotic stimulation of the median preoptic nucleus (MnPO) predominantly produced excitation of paraventricular (PVN) neurosecretory cells in the rat. By contrast osmotic stimulation of the medial septal region was without effect, although electrical stimulation excited most cells. The results suggest that the MnPO is one of the osmosensitive sites controlling electrical activity of PVN neurosecretory cells.

Action Potentials↗

PubMed1992

Estrogen fails to reduce tuberoinfundibular dopaminergic neuronal activity and to cause a prolactin surge in lactating, ovariectomized rats.

The activity of tuberoinfundibular dopaminergic (TIDA) neurons was estimated by measuring the concentrations of dihydroxyphenylacetic acid (DOPAC) in the median eminence of ovariectomized lactating rats, ovariectomized non-lactating female rats and castrated male rats in correlation with the estrogen-induced prolactin (PRL) surge. PRL surge with a peak at 17.00 h was observed in ovariectomized non-lactating rats but not in the other groups. DOPAC levels were significantly lower at 17.00 h than at 11.00 h in non-lactating female rats, but there was no change of DOPAC levels in lactating rats and male rats. These results indicate that TIDA neuronal activity is inhibited at the time of estrogen-induced PRL surge and that the TIDA neurons may alter their function to result in refractoriness of PRL response to estrogen in the lactating rat.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1992

The area postrema is not involved in osmotic activation of neurosecretory cells in the supraoptic nucleus.

Experiments were performed to examine whether or not the area postrema (AP) is involved in the osmotic control of neurohypophysial hormone release. In control rats and in rats bearing extensive lesions of AP, extracellular action potentials were recorded from neurosecretory cells in the supraoptic nucleus (SON) and firing rates determined before and after the intraperitoneal (i.p.) injection of 1.5 M-NaCl solution. Lesion of the AP significantly (p less than or equal to 0.05, Mann-Whitney's U-test) lowered firing rate of putative vasopressin (phasic) cells but not that of oxytocin (non-phasic) cells. In lesioned animals, i.p. injection of hypertonic saline, however, caused similar changes in plasma osmotic pressure, plasma oxytocin concentration and mean firing rates of both putative oxytocin and vasopressin cells to those in control rats. The results suggest that the osmotic control of SON neurosecretory cell activity in the rat can take place in the absence of the AP.

Animals↗

PubMed1992

Effects of antiviral agents on chronic hepatitis B. Analysis using Cox proportional hazard model.

Two hundred fifteen courses of antiviral treatment including interferon with or without steroid withdrawal, adenine arabinoside with steroid withdrawal, and steroid withdrawal alone were given to 175 patients with HBe-antigen positive chronic hepatitis B. The effectiveness was judged on loss of HBe antigen and formation of anti-HBe, and was compared with 80 controls. According to cumulative HBe seronegative and seroconversion rates as analyzed by the Kaplan-Meier method, interferon with steroid withdrawal increased both the cumulative HBe seronegative and seroconversion rates significantly (P < 0.0001). Adenine arabinoside with steroid withdrawal and interferon alone increased the cumulative HBe seronegative rate only (P < 0.001). The Cox proportional hazard regression model was fitted to the data of 188 cases whose pretreatment liver biopsy specimens were obtained. Among treatment protocols, interferon with steroid withdrawal shortened both the HBeAg-positive period and the duration until anti-HBe becomes reactive significantly (P < 0.0001). Interferon without steroid withdrawal and adenine arabinoside with steroid withdrawal shortened the HBeAg positive interval only (P < 0.05). Among patients' characteristics, female and advanced liver histology were favorable factors. Effects of treatment protocols were analyzed after averaging each parameter of the patients' characteristics. Interferon and adenine arabinoside with steroid withdrawal shortened the HBeAg-positive interval significantly (P < 0.0001 and P < 0.05, respectively), and interferon alone showed a tendency to shorten the interval. In particular, interferon with steroid withdrawal increased the chance of losing HBeAg 7.3 times more than control. The effectiveness of antiviral treatment on chronic hepatitis B, especially the priority of interferon with steroid withdrawal, was thought to be established through this study.

Antiviral Agents↗

PubMed1992

Lesion and electrophysiological studies on the hypothalamic afferent pathway of the milk ejection reflex in the rat.

The afferent pathway of the milk ejection reflex in the hypothalamus was investigated with lesion and electrophysiological methods in anesthetized lactating rats. Destruction of the central region of the mid-hypothalamus (n = 12) blocked milk ejections induced by suckling, while that of the lateral region (n = 7) had no effect. In an electrophysiological study, extracellular recordings of neurons antidromically activated by electrical stimulation of the supraoptic nucleus were obtained from the ipsilateral hypothalamus caudal to the paraventricular nucleus (n = 84). Thirty-nine neurons were examined to see whether their firing activities changed during the milk ejection reflex. A group of 13 neurons were found to show changes in their activities prior to the reflex milk ejection; the neurons displayed a brief high-frequency burst of spikes before each milk ejection in the same manner as oxytocin neurons, and none of them antidromically responded to electrical stimulation of the neurohypophysis. The bursting neurons were recorded from the dorsomedial hypothalamic nucleus (n = 6), the region just lateral to that nucleus (n = 3) and the posterior hypothalamus (n = 4). The locations were included in a region whose destruction blocked the milk ejection reflex. These results indicate that the afferent pathway of the milk ejection reflex in the rat runs through the medial portion of the hypothalamus posterior to the paraventricular nucleus and that this region contains neurons which relay the input to the oxytocin neurons projecting in the neurohypophysis.

Afferent Pathways↗

PubMed1992

Horseshoe anomaly of the pancreas.

A 72-year-old man with recurrent pancreatitis and a horseshoe-shaped anomaly of the pancreas is described. The diagnosis was made by endoscopic retrograde cholangiopancreatography (ERCP) and computed tomography scan; laparotomy was confirmatory. The abnormal duct branched to the lower left from an enlarged Santorini's duct; a thin Wirsung's duct was joined at its distal portion to the junction of the abnormal duct. The anomaly was associated with a cystic dilatation of the common bile duct with stone and cholecystolithiasis. This anomaly is considered to be a variation of the dominant dorsal duct syndrome.

Aged↗

PubMed1992

Effects of stress on the development of chronic pancreatitis.

In this study, the effects of chronic water immersion stress on the pancreas were investigated in four groups of rats (each group, n = 9): stress + cerulein group, stress group, cerulein group, and control group. Stress + cerulein rats were treated with water immersion stress for 5 h and two intraperitoneal injections of 20 micrograms/kg body wt of cerulein once a week for 16 weeks. In the macroscopic findings of the pancreas, all rats in the stress+cerulein group exhibited moderate or distinctive congestion of blood vessels, gland atrophy, and fatty changes, while some of them showed bleeding. Microscopically, they all exhibited moderate or severe fibrosis, inflammatory cell infiltration, fatty changes, destruction of lobular architecture, and hemosiderin deposits, while some of them also showed bleeding. The stress group without treatment with cerulein injections showed slight fibrosis, hemosiderin deposits, and bleeding. The cerulein group without stress treatment showed fatty changes, but no inflammatory cell infiltration or fibrosis. In the stress + cerulein group only, the contents of digestive enzymes and protein in the pancreas were approximately 55% lower than those of the control group, whereas those in other groups did not show significant reduction. These findings suggest that stress plays some role in the development of chronic pancreatitis, perhaps by causing circulatory disturbance and blood vessel injury.

Amylases↗

PubMed1992

Posttransfusion hepatitis in Japan.

The incidence of posttransfusion hepatitis and the rate of chronicity were investigated in a program devised at our hospital in December, 1982. Out of 2,596 blood recipients between January, 1982, and December, 1987, 451 (22.7%) developed posttransfusion hepatitis. Seventy-seven patients out of 217 (35.3%) whose course was closely followed progressed to chronicity. The incidence of posttransfusion hepatitis increased with the volume of transfused blood without any evident limitation. Recipients of elevated-ALT donor blood (greater than 26 Karmen units) were found to be more susceptible to posttransfusion hepatitis than those who had received only normal-ALT donor blood. Packed red blood cells, whole blood and fresh whole blood were high-risk components, and fresh frozen plasma a low-risk component of blood. The carrier rate of non-A, non-B hepatitis agents in Japanese healthy blood donors was determined to be 1.2% using the Frost-Reed model of infectious diseases. Anti-hepatitis C virus was detected in 62% of the cases of posttransfusion hepatitis 1 year after transfusion.

Acute Disease↗

PubMed1992

Small renal cell carcinoma: pathologic and radiologic correlation.

The authors correlated the radiologic and pathologic findings of 36 patients with small renal cell carcinoma (less than or equal to 3 cm in diameter). Tumors were discovered incidentally or by means of mass surveys with ultrasound (US). Computed tomography (CT) and angiography were performed before surgery. Of the 36 tumors, 24 were of solid (alveolar) architecture, five were of papillary architecture, three were of tubular architecture, and four were of multilocular cystic architecture. Cell arrangement was closely correlated with radiologic appearance, especially in regard to tumor vascularity and echogenicity. Histologically homogeneous tumors of solid architecture were hypoechoic at US and hypervascular at angiography and contrast medium-enhanced CT. Tumors of papillary, tubular, and multilocular cystic architecture were hyperechoic at US and hypovascular at angiography. There was no correlation of cell differentiation and cell architecture with echogenicity or tumor vascularity. Tumors with hemorrhage showed marked hyperattenuation at CT. A tumor capsule was observed in 25 patients (69%); this was demonstrated as a rim at US or angiography.

Adult↗

PubMed1992

Abolition of prolactin surge induced by ovarian steroid hormones in the lactating rat.

There are data indicating that stress-induced prolactin (PRL) release is blunted in the lactating rat like the release of other stress-associated hormones. In this experiment, the PRL release evoked by administration of estrogen, which is another principal stimulus for PRL release, was examined in ovariectomized lactating rats 8-15 days after delivery. Estradiol benzoate (EB, 20 micrograms) injections into ovariectomized nonlactating rats induced a PRL surge starting between 13:00 and 15:00 h with a peak at 17:00 h 2 days after the treatment, whereas the EB-induced PRL surge was absent in ovariectomized lactating rats separated from their pups at 09:00 h on the day or in mothers without separation from their pups. Injection of either thyrotropin-releasing hormone (TRH; 10 micrograms/kg) or pimozide (0.5 mg/kg) elevated serum PRL concentrations similarly in lactating and nonlactating rats when examined just before the beginning of the expected estrogen-induced PRL surge. Thus, the main cause for the reduced PRL response to estrogen in lactating rats seems not to be in the pituitary gland but in the brain. Progesterone, which is known to induce a PRL surge in ovariectomized estrogen-primed rats by acting on the mediobasal hypothalamus, also failed to evoke a PRL surge in lactating rats. Recovery from the inhibitory influence of suckling on PRL response to EB followed a time course similar to that observed in response to immobilization stress or to morphine injection; estrogen-induced PRL surge started to recover at 6 days and was almost fully recovered 8 days after weaning.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

[A case of asymptomatic Dandy-Walker syndrome with cerebellar hemorrhage].

A case of asymptomatic Dandy-Walker syndrome (DWS) complicated by cerebellar hemorrhage is reported. A 65 year-old man was hospitalized for investigation and treatment of disturbance of consciousness. CT scan and MRI showed a large hematoma in the posterior fossa cyst. Postoperative CT scan and MRI revealed the DWS and cerebellar hemorrhage on the left side. This patient had no symptom until 65 years of age, in spite of having DWS. There has been no such case reported in the literature to our knowledge. Derangement of secretion and absorption of cerebrospinal fluid seem to have been the cause of late-onset symptoms after a long well balanced symptom-free period.

Aged↗

PubMed1992

Pharmacological studies of the new antiinflammatory agent 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-o ne. 1st communication: antiinflammatory, analgesic and other related properties.

The antiinflammatory, analgesic and antipyretic activities of 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-on e (T-614, CAS 123663-49-0) were investigated in various animal models and compared with those of nimesulide, indomethacin and ibuprofen. The antiinflammatory potency of T-614 on carrageenin-induced paw edema, paper disk granuloma and established adjuvant arthritis was greater than that of ibuprofen, but slightly lower than those of nimesulide and indomethacin. In acute inflammatory models, unlike indomethacin, T-614 suppressed the edemas provoked by dextran and bromelain in rats, but its inhibitory action on ultraviolet erythema in guinea-pigs was weak. Although the analgesic activity of T-614 was hardly demonstrated in writhing tests in mice, its potency against the inflammatory pain such as Randall-Selitto test, adjuvant-induced hyperalgesia and antigen-induced arthritic pain in rats was superior to that of ibuprofen. Moreover, it had a potent analgesic effect on urate-induced synovitis in dogs. T-614 exerted a prompt and strong antipyretic effect in both yeast-induced febrile rats and lipopolysaccharide-induced febrile rabbits. T-614 had virtually no gastrointestinal ulcerogenic action and did not affect water and sodium excretion in rats. T-614 is a novel antiinflammatory compound with different pharmacological properties from that of the reference drugs.

Animals↗

PubMed1992

[An autopsied case of progressive systemic sclerosis with anti Wa antibody who showed a rapid progression].

An anti Wa antibody was reported as a new t-RNA related protein antibody in 1986. This autoantibody is now considered specific for the diagnosis of progressive systemic sclerosis (PSS). Up to date only 5 cases with anti Wa antibody have been identified. We report here an autopsied case of PSS with this antibody. A 53 years old female was admitted to our hospital because of dry cough and dyspnea in Sep 1987. There were fine crackles and chest X ray revealed interstitial pneumonia. The progressive respiratory failure was treated by steroid pulse therapy effectively. Sclerotic skin changes of hand began to appear in Sep 1988 and rapidly progressed to arms, chest and forehead by Dec 1988. A skin biopsy confirmed PSS changes. An anti Wa antibody was detected by double immunodiffusion and the protein antigen was associated with t-RNA when immunoprecipitation was conducted. She died of heart failure in July 1989. An autopsy revealed the diffuse fibrotic change of the heart and the lung. Cases with anti Wa antibody were shortly reviewed from the literature.

Autoantibodies↗

PubMed1992

[A case of pulmonary alveolar proteinosis and disseminated atypical mycobacteriosis complicating chronic myelogenous leukemia].

A 47-year-old woman with chronic myelogenous leukemia was treated with daily busulfan (total dose approximately 500 mg) from December 1988 to January 1990. The disease thereafter remained stable with no evidence of blastic transformation. In February 1990 she developed productive cough and abnormal acinar lung shadows appeared transiently on her chest X-ray. In October 1990, productive cough and linear and abnormal acinar lung shadows reappeared. Expectorated sputa contained acid-fast bacilli (Gaffky 6, 10). Antituberculous therapy was started, which caused severe liver dysfunction. She was admitted to our hospital for evaluation of abnormal lung shadows. Transbronchial lung biopsy revealed pulmonary alveolar proteinosis with thickening of alveolar septa. The alveolar septal thickening was suspected to be a pathological change following pulmonary alveolar proteinosis. Cultures from sputum, cerebrospinal fluid, and bone marrow aspiration specimens revealed atypical mycobacterium (M. avium complex), and the diagnosis of disseminated atypical mycobacteriosis was established. The pathogenesis of the disseminated atypical mycobacteriosis was considered to be superinfection by mycobacteria.

Busulfan↗

PubMed1992

[Primary intracranial melanoma: a case report].

A rare case of primary intracranial melanoma is presented in a 34-year-old man with initial symptoms of persistent headache. In magnetic resonance imaging(MRI), this case had all the characteristic findings of intracranial melanoma which had been reported previously. In 123I-iodoamphetamine-single photon emission CT (123I-IMP-SPECT), abnormal accumulation of 123I-IMP was recognized in early and late phase imaging, which was very specific to the lesion. This is the first report of 123I-IMP-SPECT performed on a primary intracranial melanoma. Tumor mass originated from pia mater was surgically resected, but the dissemination of tumor cells was recognized macroscopically. Pathological examination of the specimen showed very little malignant changes of melanoma cells, which was in contrast to the previous reports. Although, no standard chemotherapy of the primary intracranial melanoma has been established, DAV therapy to the dissemination of tumor cells into the subarachnoid space, and intravenous administration of interferon-beta were performed in this case. Methods of differential diagnosis and treatments of primary intracranial melanoma are reviewed and discussed.

Adult↗

PubMed1992

Thromboxane A2 receptor characterization in human astrocytoma cells and rabbit platelets by a new thromboxane antagonist, [3H]ONO NT-126.

Thromboxane A2 receptors of human astrocytoma cells and rabbit platelets were characterized by a binding of a new potent and selective thromboxane A2 antagonist, [3H]ONO NT-126. [3H]ONO NT-126 bound with a high affinity to membranes derived from astrocytoma cells and platelets. In astrocytoma cells, the nonspecific binding determined by 1 microM S-145 was observed in high percentage to total binding. Scatchard plots of both membranes were linear, expressing a single binding site with the Kd of 0.17 nM and Bmax of 46.4 fmol/mg protein in astrocytoma cell membranes and with the Kd of 0.28 nM and Bmax of 1585 fmol/mg protein in platelet membranes, respectively. [3H]ONO NT-126 binding was displaced most potently by ONO NT-126 among other thromboxane A2 analogues. [3H]ONO NT-126 binding was displaced by ONO NT-126, S-145, SQ29548, STA2 and U46619 with Ki values (nM) of 0.21, 1.14, 7.05, 23.5 and 235 in astrocytoma cell membranes and 0.23, 5.55, 259, 9.25 and 43.7 in platelet membranes, respectively. The characteristics of TXA2 receptors apparently differ in rabbit platelets and human astrocytoma cells.

Animals↗

PubMed1992

[A case of tricuspid pouch associated with ventricular septal defect and functional left ventricular-right atrial communication].

We reported a 60-year-old woman with tricuspid pouch associated with ventricular septal defect and subsequent left ventricular-right atrial communication. Preoperative angiographic findings suggested the presence of membranous septal aneurysm, ventricular and atrial septal defects, and tricuspid insufficiency. However, at operation, besides perimembranous inlet type ventricular septal defect, a pouch, 1.5 cm in diameter was found in the adjacent part to the septal leaflet within the anterior one of the tricuspid valve. The ventricular septal defect was closed with a patch. From these findings, it is speculated that the tricuspid pouch was formed by the effect of jet stream through the ventricular septal defect.

Diagnosis, Differential↗