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Biomedical subjects

K Kadowaki

Publications and source records attributed to K Kadowaki.

At least 127 records · Page 7Linked to original sources
PubMed1990

Dopamine inhibits the arachidonate and prolactin release stimulated by thyrotropin-releasing hormone through an islet-activating protein-sensitive GTP-binding protein in anterior pituitary cells.

Coupling of the dopamine (DA) receptor to the pathway of arachidonate (AA) through the islet-activating protein (IAP)-sensitive GTP-binding (G) protein was examined in primary cultures of anterior pituitary cells. The inhibitions by 1 microM DA of the stimulations of prolactin (PRL) release by 100 nM thyrotropin-releasing hormone and by 10 microM calcium ionophore A23187 were blocked by 100 ng/ml IAP. DA at 1 microM did not inhibit the release of [3H]-AA induced by 100 mU/ml phospholipase A2 (PLA2), but it inhibited the release of PRL induced by 100 mU/ml PLA2. This inhibition was blocked by 100 ng/ml IAP. IAP also blocked the inhibitions by DA of the releases of PRL by 5 microM AA and by 5 microM 5-hydroxyeicosatetraenoic acid. These results suggest that the DA receptor on lactotrophs is coupled to the pathway following the release of AA (lipoxygenase) through the IAP-sensitive G protein.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1990

Adenosine 3',5'-cyclic monophosphate enhances dopamine accumulation in rat hypothalamic cell culture containing dopaminergic neurons.

The regulation of dopamine accumulation in cultured rat hypothalamic cells by adenosine 3',5'-cyclic monophosphate (cAMP) was investigated in cultures of newborn rat hypothalamic cells. Both dibutyryl cAMP, (Bu)2-cAMP, and forskolin enhanced [3H]dopamine accumulation in a dose-dependent manner. cAMP also enhanced [3H]dopamine accumulation, but to a lesser degree. Neither n-butyrate nor adenosine alone enhanced [3H]dopamine accumulation. (Bu)2-cAMP had no effect on basal efflux of [3H]radioactivity. The effect of (Bu)2-cAMP appeared on day 5 of culture, reached a maximum on day 6, and then rapidly decreased. These results suggest that dopamine uptake by cultured rat hypothalamic cells is regulated by intracellular cAMP.

Adenosine↗
PubMed1990

[PET evaluations of ischemic heart disease showing transient ST-T elevation: report of two cases].

Positron emission tomography (PET) was performed in two patients who exhibited transient ST-T elevation during their attack. The myocardial blood flow (MBF) and tissue fraction were quantitatively measured using dynamic PET and O-15 water. Myocardial exogenous glucose utilization was also determined by PET and F-18 fluoro-deoxyglucose (FDG). The FDG uptake index (FUI), obtained by dividing the total FDG count in the region of interest by the total amount of FDG, was used. These values were free from the partial volume effect because of the correction of the tissue fraction. Case 1: A 61-year-old woman was admitted to our hospital because of ST-T elevation on her ECG during her abdominal surgery. Her myocardiogenic enzymes were elevated. The emergency coronary angiogram showed no pathological coronary artery stenosis or occlusion, but the levogram showed abnormal wall motion. About one month later, the repeat coronary angiogram showed restoration to normal wall motion. In a PET study, myocardial blood flow and FUI were increased above the normal range. Case 2: A 65-year-old man was admitted to our hospital because of ST-T elevation on his ECG during chest oppression. In a PET study one month after the last chest pain, myocardial blood flow was normal, but there was a high uptake of FDG in the transient ischemic area. The coronary angiogram revealed no pathological lesions. It was suggested that the high uptake of FDG is related to a previous ischemic event; not to a present ischemic state. It is thought that these two cases exemplify so-called "myocardial stunning".

Aged↗
PubMed1990

[Influence of ventriculoatrial conduction on hemodynamic consequences in patients with artificial pacing].

To assess the hemodynamic consequences associated with ventriculoatrial (VA) conduction following pacemaker implantation, 22 subjects with the sick sinus syndrome were studied using two-dimensional echocardiography (2DE) and Doppler techniques, including pulsed Doppler (PD). Pacemakers used were unipolar, programmable pulse generators which can operate in the DDD and VVI modes. A simultaneous strip chart recording of 2DE, phonocardiogram and ECG was obtained in each mode. Systolic time intervals (STI) and left ventricular diameters were measured using 2DE. Left ventricular ejection time (LVET) was determined from the aortic valve echo, which was the interval between the opening and closure of the cusp. Left ventricular pre-ejection period (LVEPEP) was the interval between the Q wave of the ECG and the opening of the aortic valve. Right ventricular (RV) STI were also measured using the pulmonary valve echo in a manner similar to that used with the aortic valve echo. Stroke volume and ejection fraction were calculated by conventional methodology. RVET was longer than LVET; RVPEP was shorter than LVPEP. These two STIs were shortened using an incremental pacing rate in each mode. Similarly, the stroke volume and ejection fraction decreased, depending on the pacing rate at a range of 50-110 b/min. RVET and LVET in DDD were longer than those in VVI. RVPEP and LVPEP in DDD were shorter than those in VVI. Stroke volume and ejection fraction in DDD were smaller than those in VVI. There was a significant difference (p less than 0.05) between DDD and VVI. These differences became significantly (p less than 0.01) greater between DDD without VA conduction and VVI with VA conduction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Roentgenographic manifestations of peripheral bronchogenic carcinomas].

Peripheral bronchogenic carcinomas in early clinical stage are discovered by plain chest roentgenogram, and good prognosis will be expected by surgical resection. 20 bronchogenic carcinomas (18 adenocarcinomas, one squamous cell carcinoma, and one large cell carcinoma) in 19 patients were examined. 9 cases presented noduler lesion on the plain chest roentgenogram, and the other presented 7 focal patchy shadow and 4 band-like shadow. Thin-section CT could demonstrated indented pleura (95%), notch (95%), convergence of peripheral vessels (70%), irregular border (75%). In adenocarcinomas, thin-section CT demonstrated airbronchogram or airbronchiologram (61%), multiple small cavitation (61%), and heterogeneous density (56%). CT-pathologic correlation proved thin-section CT could demonstrate tumor's internal texture and fine detail of tumor-lung interface. Small peripheral lung cancer in early stage could be discovered by plain chest roentgenogram, and thin-section CT was useful for the diagnosis of small peripheral bronchogenic carcinomas, especially adenocarcinomas.

Adenocarcinoma↗
PubMed1990

[Clinical statistics of the bladder tumor--transurethral resection cases].

Two hundred and thirty one patients who underwent transurethral resection of a bladder tumor (TUR-Bt) at our hospital during the past 15 years were analyzed. There were 176 males and 55 females, and the average age at the initial TUR-Bt was 62 years old. Histopathologically, 225 cases were of transitional cell carcinoma, 4 cases of papilloma and 2 cases of squamous cell carcinoma. Grading and staging of 225 transitional cell carcinoma cases revealed grades 1, 2 and 3 in 32, 132 and 21 cases, and stages Ta, T1, T2, T3 and T2-4M1 in 48, 135, 20, 17 and 11 cases, respectively. The frequency of TUR-Bt varied from 1 to 10 times. Among the 231 cases TUR-Bt was done once, twice and three times in 149 (64.5%) and 41 (17.8%), and 22 (9.6%) cases, respectively and the total number of TUR-Bt was 400 times. The duration of the TUR-Bt operation was from 5 min. to 160 min. (mean: 32.4 min.) and the resected weight of tumor between 0.5 g and 85 g (mean: 5.4 g). As a complication of TUR-Bt, TUR-fulguration was necessary to control postoperative bleeding in 7 cases (1.7%), and blood transfusion was required in 13 cases (3.3%) during TUR-Bt. Postoperatively blood transfusion was required in 8 cases (2%), intraperitoneal perforation in 2 cases (0.5%), extraperitoneal perforation in 6 cases (1.5%) and hyponatremia in 1 case (0.3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Right thoracic kidney with simple renal cyst: report of a case].

A case of right thoracic kidney with simple renal cyst is reported. A 67-year-old man was pointed out to have an abnormal shadow in the right lower lung field of chest X-ray film. He was asymptomatic. Laboratory test was normal. Computed tomography and excretory urography confirmed the right thoracic kidney with a simple cyst. Adrenal scintigraphy revealed a high ectopic adrenal gland with right thoracic kidney. Since he was asymptomatic, treatment was not required. High ectopic kidney is extremely rare and 74 cases have been reported in the domestic literature in Japan. Thoracic kidney should be considered as one of differential diagnoses of abnormal mediastinal shadow.

Aged↗
PubMed1990

[Airbronchogram sign in small peripheral bronchogenic carcinomas].

18 bronchogenic carcinomas (16 adenocarcinomas, one squamous cell carcinoma, and one large cell carcinoma) in 17 patients and the control group (benign nodules) were examined with high resolution and thin section CT. Thin-section CT images showed airbronchogram or airbronchiologram in 63%, multiple small cavitations in 63%, and heterogeneous densities 50% of the adenocarcinomas with excellent spatial and contrast resolution. Airbronchogram or airbronchiologram was not seen in other types of bronchogenic carcinomas and benign nodules. Therefore, demonstration of airbronchogram or airbronchiologram in nodular lesions can make the CT diagnosis of small peripheral bronchogenic carcinomas, especially adenocarcinomas.

Adenocarcinoma↗
PubMed1989

[Thin-section computed tomography of intrapulmonary metastases after surgical resection of lung cancer].

To evaluate the morphology of small peripheral intrapulmonary metastases of lung cancers, we studied thin-section computed tomography (CT) images of 12 lesions in 5 cases (1 squamous cell carcinoma, and 4 papillary adenocarcinomas). All lesions were resected, and histopathological diagnosis of them was performed in comparison with primary lesions to differentiate multiple primary lung cancers from intrapulmonary metastases. Thin-section CT images showed mildly lobulated nodules in connection with supplying pulmonary vessels, however, indented pleura and vascular convergence were less frequently seen in intrapulmonary metastases in contrast with primary lung cancers. Thin-section CT is helpful for distinguishing multiple primary lung cancers from intrapulmonary metastases in patients with a history of surgical resection for lung cancers.

Adenocarcinoma, Papillary↗
PubMed1989

Gene for proliferating-cell nuclear antigen (DNA polymerase delta auxiliary protein) is present in both mammalian and higher plant genomes.

Proliferating-cell nuclear antigen (PCNA; also called cyclin) was originally described in proliferating mammalian cells as a nuclear protein with an apparent Mr of 33,000-36,000 and recently was found to be a DNA polymerase delta auxiliary protein. To elucidate whether PCNA/cyclin is a universal protein necessary for proliferation of eukaryotes, a search was conducted for PCNA/cyclin homologues in higher plants. In Southern blot-hybridization analysis, a rat PCNA/cyclin cDNA probe hybridized with homologous sequences in genomic DNAs from rice, soybean, and tobacco. A PCNA/cyclin-related molecular clone (pCJ-1) was isolated from rice DNA and was partially sequenced. The pCJ-1 probe hybridized with a 1.2-kilobase transcript in RNA from rice root tips and shoots. Immunoblot analysis of the soluble extract of soybean root tips with monospecific anti-PCNA/cyclin identified an immunoreactive protein with an apparent Mr of 34,000. Immunohistochemical analysis revealed the presence of an immunoreactive PCNA/cyclin protein in the nuclei of cells in the meristem of soybean root tips. The highly homologous nature of the gene for PCNA/cyclin throughout the animal and plant kingdoms suggests that the product of the gene plays an essential role in DNA replication in eukaryotes.

Amino Acid Sequence↗
PubMed1989

Squamous cell carcinoma of the uroepithelium: CT evaluation.

Fourteen cases of primary squamous cell carcinoma (SCC) originating in the uroepithelium were studied with computed tomography (CT). Nine cases were of vesical origin, three were of renal pelvic origin, and two were of ureteral origin. CT scans of eight of the 14 cases, including four cases of vesical origin and four cases of renal pelvic or ureteral origin, demonstrated predominantly extraluminal extension with invasion into adjacent organs or the renal parenchyma. CT scans of the remaining six cases showed almost equal extra- and intraluminal tumor growth and no predominantly intraluminal extension. An associated urinary stone was demonstrated in four of the five cases of SCC of renal pelvic or ureteral origin. Two of these cases were diagnosed as urinary stones before CT was performed. Eight of the nine cases of SCC of vesical origin and four of the five cases of SCC of renal pelvic or ureteral origin were correctly staged with the aid of CT.

Aged↗
PubMed1989

Involvement of extracellular calcium and arachidonate in [3H] dopamine release from rat tuberoinfundibular neurons.

The mechanism of [3H]dopamine [( 3H]DA) release was investigated using primary cultures of dispersed cells from the rat tuberoinfundibular region, which contains tyrosine hydroxylase (TH)-like immunoreactive neurons. The calcium ionophore A23187 at 10 nM and above caused a significant and dose-dependent increase in [3H]DA release. In the presence of 50 microM A23187, [3H]DA release was detectable within 30 s and reached a plateau in 15 min. The induction of [3H]DA release by 50 microM A23187 was abolished by lowering the extracellular calcium concentration with 2 mM EDTA. Maitotoxin, another calcium-channel activator, also increased [3H]DA release at a concentration of 50 ng/ml. Exogenous additions of 100 mIU/ml phospholipase A2 and 10 microM arachidonate caused significant release of [3H]DA. Furthermore, A23187 stimulated [3H]arachidonate release from tuberoinfundibular dopaminergic (TIDA) neurons in a dose- and time-dependent manner. These results suggest that extracellular calcium and arachidonate are involved in the process of [3H]DA release from rat TIDA neurons.

Animals↗
PubMed1989

[Potentiation of combination effect of cisplatin and radiation--application of biological response modifiers].

The combination antitumor effect of three kinds of biological response modifiers (lentinan, PSK and juzentaiho-to) was evaluated in the treatment of IMC solid carcinoma with CDDP (9 mg/kg) and/or radiation (1000 rad). Remarkable antitumor effects were observed in the lentinan (2 mg/kg, daily) group to which a single dose of CDDP was given 24 hours before irradiation. On the other hand, combined therapy with CDDP and radiation alone showed less antitumor effect. No antitumor effect was observed in the groups treated with biological response modifiers (BRM) alone. Winn's test was performed to investigate the level of immunity on each treatment group. Mice were inoculated with the admixtures of immunized spleen cells and IMC carcinoma cells at a ratio of 200:1. Tumor growth was completely suppressed in the groups of CDDP and lentinan with or without radiation even on the 41st day after inoculation. These results are strongly suggestive of potentiation of the immunity of tumor bearing mouse by the combined use of lentinan. Histopathological evaluation also revealed a potent antitumor effect of combined use of lentinan. Since host immunity is known to be suppressed in the tumor bearing state, combined use of BRM in chemo-radiotherapy must play an important role in the treatment of malignant tumor.

Adjuvants, Immunologic↗
PubMed1989

[Computed tomography of gastric cancer].

CT scans of 52 patients with advanced gastric cancer were reviewed, and the layer structure of the gastric wall was analyzed. Administration of 600 ml water, orally, expanded the gastric wall, while patients were in the prone position. Intravenous infusion of contrast media was routinely administered. We found that the normal layer structure of the gastric wall could be shown despite the cancer in the lesion. Borrmann 3 and 4 types. We guess that CT has a possibility in the assessment of the spread in the wall of gastric cancer.

Humans↗
PubMed1989

[Radio-Geometric consideration of basal indentation using phantoms and specimens].

With the aid of colon-polyp phantoms, basal indentation (BI) of polypoid lesions on double-contrast examinations of the colon was studied. Our findings indicated that BI is a function of radio-geometric projections and its morphology (arcuate, angular and trapezoid) depends on size, shape and surface pattern of a polypoid lesion. These findings were also substantiated by specimen and clinical radiography.

Colonic Polyps↗