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T Okamura

Publications and source records attributed to T Okamura.

At least 631 records · Page 35Linked to original sources
PubMed1987

[Centrifugal ultrafiltration method for determining the percent of free testosterone in serum].

Serum free testosterone (T) % in the follicular phase of 11 normal women, 11 normal men and 30 pregnant women of 5 to 39 weeks of gestation were determined by the centrifugal ultrafiltration method (CUF), which was performed at the centrifugation of 5 minutes, 1000 g and 37 degrees C, using the Amicon MPS-3 and YMT membrane. These conditions were shown to be appropriate for measuring the free T. There was a significant correlation between the percentage of free T due to the CUF and the equilibrium dialysis method (ED) (r = 0.88, p less than 0.01). Serum free T % and free T concentrations by the CUF method were, respectively, 2.89 +/- 0.09 (SE) % and 166.3 +/- 9.8 pg/ml in normal men, 1.76 +/- 0.09% and 9.4 +/- 0.7 pg/ml in non-pregnant women and 1.14 +/- 0.03%, 22.4 +/- 1.4 pg/ml in pregnant women. Serum free T % in non-pregnant women was significantly lower than in men (p less than 0.001) and higher than in pregnant women (p less than 0.001). In the CUF method the intra-assay CV was 4.9% in women, 6.0% in men and the inter-assay CV was 5.1% in women, 6.2% in men. The CUF method was more simple, rapid and accurate on the determination of the free T in serum than the ED method.

Centrifugation↗
PubMed1987

Multiple species of bovine adrenodoxin mRNA. Occurrence of two different mitochondrial precursor sequences associated with the same mature sequence.

Bovine adrenodoxin mRNA is found to consist of several distinct mRNA species which can be divided into two sets. Each set utilizes at least three of four separate poly(A)+ addition sites providing an explanation of the three sizes of adrenodoxin mRNA (1.75, 1.4, and 0.95 kilobases) previously observed in bovine adrenocortical RNA by this laboratory (Okamura, T., John, M.E., Zuber, M.X., Simpson, E.R., and Waterman, M.R. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 5705-5709). The two sets are distinguished from one another by a unique 5' sequence leading to two different amino acid sequences (approximately 10% homology) for the precursor portion of this nuclear encoded, mitochondrial protein. A common mature adrenodoxin sequence is encoded by both sets of mRNA. One set of RNAs is 10-fold more abundant than the other, but the levels of both sets can be induced by treatment of primary bovine adrenocortical cell cultures with adrenocorticotropin. The biological significance of these two types of adrenodoxin precursor sequences remains obscure.

Adrenal Cortex↗
PubMed1987

Mature bovine adrenodoxin contains a 14-amino-acid COOH-terminal extension originally detected by cDNA sequencing.

Since the nucleotide sequence of bovine adrenodoxin cDNA is at variance with protein sequencing data in that it encodes an additional 14 amino acids at the COOH terminus, we used a specific antibody raised against this 14-amino-acid segment to examine its presence in: nascent precursor polypeptide chains, the processed mature adrenodoxin and mitochondria of both steroidogenic and nonsteroidogenic tissues. These studies reveal the presence of the extra peptide in the precursor form derived from in vitro translation and in the newly synthesized mature form as shown by [35S]methionine labeling of proteins in adrenocortical cells. Both the purified COOH-terminal synthetic peptide and purified mature adrenodoxin competed with radiolabeled adrenodoxin for immunoprecipitation by the anti-peptide antibody. Immunoblots revealed the presence of the extra peptide in purified adrenodoxin and in bovine adrenocortical, corpus luteal, kidney and liver mitochondria while it was not detectable in heart mitochondria. Thus, we conclude that mature adrenodoxin and its homologs in non-steroidogenic tissues contain the C-terminal extension following uptake into mitochondria. These results indicate structural homology between adrenodoxin and the iron-sulfur proteins of the kidney and liver and also suggest the presence of a second iron-sulfur protein in kidney and liver.

Adrenal Cortex↗
PubMed1987

Heterogeneity in mechanisms of bradykinin action in canine isolated blood vessels.

The relaxation induced by bradykinin in helical strips of coronary arteries contracted with prostaglandin (PG) F2 alpha was abolished by removal of the endothelium and was markedly suppressed by treatment with methylene blue or AA861, a lipoxygenase inhibitor. Indomethacin did not alter the response. Renal arterial relaxation by bradykinin was partially reduced by removal of the endothelium. Indomethacin moderately attenuated the response in the strips with endothelium and additional treatment with methylene blue or AA861 suppressed the response further. Tranylcypromine or diphloretin phosphate, an antagonist of PGI2, attenuated the peptide-induced relaxation. In mesenteric veins, the relaxation induced by bradykinin was slightly reduced by removal of the endothelium; indomethacin reversed the relaxation to a contraction in the strips with or without endothelium. Des-Arg9-[Leu8]bradykinin, a bradykinin B1 antagonist, did not alter the relaxation due to bradykinin in coronary arteries but reduced the response of mesenteric veins. It appears that bradykinin-induced relaxation is associated exclusively with EDRF in dog coronary arteries, with both PGI2 and EDRF in the renal arteries, and only with PGI2 liberated from endothelial and subendothelial tissues in the mesenteric veins. The release of PGI2 and EDRF may be mediated by activation of B1 and B2 receptor subtypes, respectively.

Animals↗
PubMed1987

Growth mode and DNA ploidy in mucosal carcinomas of the stomach.

Modes of cancer growth and DNA ploidy were studied in 66 patients with mucosal carcinoma of the stomach. The modes of growth were classified into five histologic patterns; elongated tubular (three patients), expansive (18 patients), tubular and solid (14 patients), carcinoma in situ (10 patients) and infiltrative (21 patients). In every patient, all or most lesions with elongated tubular, expansive, and carcinoma in situ growths were located in the pyloric gland area of the stomach, and were less than 4 cm in diameter. Histologically, the adenocarcinomas papillary or well-, or moderately differentiated. Most lesions with an infiltrative growth were located in the intermediate pyloric and fundic glands areas, depressed in gross appearance, and composed of poorly differentiated glandular or signet ring tumor cells. The lesions with a tubular and solid growth were present in the pyloric gland or intermediate area, and were classified as well-, moderately, or poorly differentiated adenocarcinoma. All lesions with an elongated tubular, tubular and solid, and carcinoma in situ growths, and most lesions with an infiltrative growth showed a narrowly restricted DNA distribution (Type I or II), while most lesions with an expansive growth had mostly a widely scattered DNA distribution (Type III), representing a higher malignant potential.

Adult↗
PubMed1987

Heterogeneity of DNA ploidy in patients with undifferentiated carcinomas of the stomach.

DNA ploidy was determined by cytophotometric DNA analysis in 20 patients with undifferentiated carcinomas of the stomach with serosal invasion. Measurements of DNA content were performed in 100 cells each in intramucosal, submucosal, muscular, and subserosal parts of a tumor. According to dispersion on the DNA histogram, DNA ploidy patterns were divided into low and high ploidy groups. Fourteen tumors (70%) showed the same ploidy in every layer (homogeneous DNA ploidy), 13 (65%) were low ploidy and, 1 (5%) was high ploidy. Heterogeneity of DNA ploidy was observed in the remaining six tumors (30%), which showed low ploidy in the mucosa, but high ploidy was observed in one or two deeper layers. In the six with heterogeneous DNA ploidy, there was more frequent metastasis to the lymph nodes (100%) and to the peritoneum (67%) than those with homogeneous DNA ploidy (50% and 21%, respectively). Cytophotometric DNA analysis of cells of undifferentiated gastric tumors suggested that there may be behavioral changes, depending on the degree of penetration into the gastric wall.

Carcinoma↗
PubMed1987

Langerhans cells and prognosis in patients with gastric carcinoma.

Infiltration of Langerhans cells (LC) and macrophages into tumor tissues was investigated using immunohistochemical methods, anti-S-100 protein and anti-lysozyme antibodies in 174 cases of gastric carcinoma. Varying population densities of S-100-positive LC were noted in tumor tissues; lysozyme-positive macrophages, however, were found in almost equal quantities. LC were mainly interspersed among the tumor cells, whereas macrophages were present in the stroma and around the necrotic foci. Although the survival time of patients with Stage I, II or IV gastric carcinoma did not relate to the density of LC, survival time in Stage III patients correlated well with the density of LC. In patients with a marked infiltration of LC, survival time was longer than in cases of only a slight infiltration (P less than 0.001). Therefore, LC in immunological defense mechanisms of the host against the tumor may be clinically effective in a certain phase of tumor development.

Carcinoma↗
PubMed1987

Roentgenological investigation of cavernous sinus structure with special reference to paracavernous cranial nerves.

We have evaluated the anatomical structure of cavernous sinuses in parasellar blocks obtained from adult cadavers to gain clinically useful information. Ten microdissectional studies of parasellar blocks (20 sides of cavernous sinus) were carried out with special emphasis on the course of paracavernous cranial nerves (3rd to 6th). These were also examined on plain radiographs. Secondly, CT investigations of the cavernous sinuses (notably as to paracavernous cranial nerves) were undertaken in twenty clinical cases having presumed parasellar lesions and in three parasellar blocks from cadavers. The results from microdissectional studies and plain radiographs were as follows. It was found that the 3rd cranial nerve entered the lateral wall of the cavernous sinus close to the antero-inferior part of the posterior clinoid on lateral projection. The 4th cranial nerve, on the other hand, entered near the postero-inferior portion of the posterior clinoid on the same view. Variations in Parkinson's triangle were fairly often noted, although marked asymmetry was not seen in individual cases. From CT findings, it was found that a postenhanced, magnified direct coronal study was essential for identifying paracavernous cranial nerves more clearly. The 3rd and 5th cranial nerves were fairly well identified on axial and coronal projections. Careful radiological investigation including plain skull radiographs & CT seems to be of value for those who diagnose or treat parasellar lesions.

Abducens Nerve↗
PubMed1987

Vascularizing the ischemic jejunum by intra-seromuscular implantation of a gastroepiploic vascular pedicle--an application of experimental esophageal reconstruction.

Many experimental studies have been done in an attempt to feed various ischemic organs. Of these, both direct intraorganic vascular implantation, and vascular anastomosis, appear to show promise for vascularizing the ischemic gastrointestinal tracts. Preliminary experiments were done in 24 Mongrel dogs to establish the blood flow of the jejunum by direct epiploic vascular pedicle implantation. Morphological development of the communicating vascular system, newly formed between the implanted epiploic vessel and the indigenous vascular network of the jejunum, was clarified by microangiography and histology. In 20 dogs, esophageal reconstruction was successfully accomplished, using the jejunal loop vascularized as described above. The total length of the jejunal segment, and the esophagojejunal anastomotic portion, had neither signs of circulatory disturbance nor necrosis, one, three and twelve months post-operatively. Our experimental findings suggest that direct vascular implantation is the simplest way to vascularize the ischemic intestinal tract and may also be applicable widely in the field of abdominal surgery.

Animals↗
PubMed1987

Biliary cystadenoma of the extrahepatic bile ducts: report of a case and review of the literature.

Benign neoplasms of the extrahepatic bile ducts are rare and there have only been thirteen reported cases of cystadenoma. One case of cystadenoma of the common hepatic duct and solitary hepatic cyst is presented here and a total of fourteen cases are reviewed. The patient was a 45 year old woman, who complained of abdominal pain with rigidity, but without jaundice. Ultrasonography of the liver showed a 6 cm cyst of the right lobe. Percutaneous transhepatic cholangiography revealed a multilobular cystic mass. At emergency laparotomy, a polypoid multilobular tumor with a stalk was found hanging from the common hepatic duct and was excised. Almost all the patients reported were middle age woman with jaundice. Preoperative diagnosis was made possible by percutaneous transhepatic cholangiography, endoscopic retrograde cholangiography or ultrasonography. The treatment of choice was complete excision. In three cases, a solitary hepatic cyst accompanied the cystadenoma of the common hepatic duct.

Adult↗
PubMed1987

Effects of intravesical instillation of antitumor chemotherapeutic and immunotherapeutic agents on bladder lesion development in rats pretreated with N-butyl-N-(4-hydroxybutyl)nitrosamine.

The effects of 12 weeks of intravesical instillation of bleomycin, cisplatinum and picibanyl on development of urinary bladder tumors and preneoplastic lesions were examined in rats pretreated with N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) for four weeks. Upon sacrifice at week 36, histopathological examination revealed a significantly reduced incidence of PN hyperplasia and a tendency for decreased papilloma generation in rats given cisplatinum. However, the other treatments were not associated with any effect on carcinogen-induced lesion development. The results demonstrate that cisplatinum has a potential for postinitiation inhibition of rat bladder carcinogenesis.

Administration, Intravesical↗
PubMed1987

Elevated vascular angiotensin converting enzyme in chronic two-kidney, one clip hypertension in the dog.

The possible role of the vascular angiotensin converting enzyme (ACE) in the development of two-kidney, one clip (2-K, 1C) hypertensive dogs was studied in different blood vessels. Vascular ACE activity per mg protein differed in a variety of blood vessels; the activity appeared to vary inversely with the outer diameter of arteries. The systemic blood pressure in mongrel dogs increased after partial occlusion of the left renal artery, and the hypertension lasted for 8 months. Plasma renin activity (PRA) was raised only for the first 4 weeks after the operation and then returned to the original level in the chronic stage of hypertension. Plasma ACE activity did not alter during the experimental period. In contrast, ACE activities in the jejunal, pulmonary and renal arteries, aorta, lung and cerebral cortex, significantly increased in the chronic hypertensive stage (8 months after occlusion). The production of angiotensin II (ANG II) from ANG I was significantly greater in isolated arteries from 8-month hypertensive dogs than in those from normotensive dogs when assessed by the contractile responses to ANG I and ANG II. These results indicate that acceleration by increased vascular ACE activity of the production of ANG II in the vascular wall may contribute to the maintenance of hypertension in the chronic stage of 2-K, 1C hypertensive dogs having normal PRA and plasma ACE activity.

3-Mercaptopropionic Acid↗
PubMed1987

Age-related changes in trimethadione oxidizing capacity.

The metabolism of trimethadione (TMO) following oral administration (4 mg kg-1) has been studied in 11 young male and 11 elderly male patients. The elimination half-life (h) of TMO was 11.8 +/- 1.4 (mean +/- s.e. mean) in the young and 23.5 +/- 2.17 in the elderly (P less than 0.01). Total body clearance (1 h-1 kg-1) was 41.4 +/- 2.8 in the young and 29.0 +/- 2.4 in the elderly (P less than 0.01). The apparent volume of distribution (1 kg-1) was 0.67 +/- 0.03 in the young and 0.65 +/- 0.04 in the elderly. Serum dimethadione (DMO)/TMO ratios at 4 h were 0.65 +/- 0.03 in the young and 0.46 +/- 0.03 in the elderly (P less than 0.01). These results suggest that N-demethylation of TMO is inversely related to age.

Adult↗
PubMed1987

Trimethadione metabolism in patients with normal liver and in patients with chronic liver disease.

Serum dimethadione (DMO)/trimethadione (TMO) ratios after oral administration of TMO have been investigated in 10 patients with normal livers, 8 patients with hepatoma and 8 patients with hepatoma and cirrhosis. Serum concentration ratios of DMO to TMO at 4 h after oral administration of TMO in patients with chronic liver disease were significantly decreased by 27% for those with hepatoma and 52% for those with hepatoma and cirrhosis. Serum DMO/TMO ratios at 4 h correlated well with liver function characteristics (total protein r = 0.741, plasma albumin r = 0.826, total bilirubin r = -0.725, cholinesterase r = 0.853) as well as with pharmacokinetic parameters (total body clearance r = 0.852, half-life r = -0.636) in both patients with normal livers and patients with chronic liver disease. This study suggests that serum DMO/TMO ratios in a blood sample obtained by a single collection after an oral administration of TMO might provide a clinically useful index of the hepatic drug-oxidizing capacity in an individual patient with chronic liver disease without determining the liver function characteristics or the pharmacokinetic parameters.

Carcinoma, Hepatocellular↗
PubMed1987

Possible role of vascular angiotensin converting enzyme in the genesis of hypertension.

This study was designed to evaluate changes in angiotensin converting enzyme (ACE) activity in 2-kidney, 1-clip renal hypertensive dogs. Blood pressure increased and remained elevated for eight months after partial clamping of the left renal artery. Plasma renin activity was increased for one month after surgery, but then returned to the pre-clamping level. SA-446, a potent ACE inhibitor, reduced blood pressure in 8 M-hypertensive dogs. Plasma ACE activities was not altered during the course of hypertension, but vascular ACE activities in the pulmonary and mesenteric arteries and the aorta were significantly increased in 8 M-hypertensive dogs. These results may indicate that ACE plays an important role in the maintenance of chronic phase of 2-kidney, 1-clip renal hypertension and that suppression of vascular ACE activities might be a mechanism underlying the hypotensive effect of ACE inhibitors.

Animals↗
PubMed1987

[Effect of intravesical instillation of the antitumor chemotherapeutic agents mitomycin C and cytosine arabinoside on rat bladder carcinogenesis initiated by N-butyl-N-(4-hydroxybutyl) nitrosamine].

The effects of intravesical instillation of cytosine arabinoside (CA), mitomycin C (MMC) and combination of CA and MMC were examined in rats pretreated with N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). Rats were given initial treatment with BBN for 4 weeks followed by intravesical instillation of drugs once a week for 12 weeks. The total observation period was 36 weeks. Instillation of MMC markedly increased the development of bladder tumors, although CA did not. Moreover, tumor incidence in the combination group was less than that with MMC only. The results indicate that the intravesical instillation of MMC promotes 2-stage bladder carcinogenesis, whereas CA does not. Moreover, it is suggested that CA inhibits the promoting effect of MMC.

Administration, Intravesical↗
PubMed1987

Effects of low-caloric diet in puerperium on prolactin, TSH estradiol and milk secretion.

Ten puerperal women were put on a 1,200 kcal diet per day for 3 days followed by an ordinary 1,800 kcal diet per day for 3 days [Low-Caloric (LC) group]. Fifteen puerperal women were put on an ordinary 1,800 kcal diet per day for 6 days[Ordinary-Caloric (OC) group]. All of the women took breakfast at 7:30 am, blood was drawn at 9:30 am and then the breasts were milked for 2 minutes with an electric breast pump starting on the day of delivery (Day 0) and continuing to Day 5. Four women in the LC and OC groups underwent a thyrotropin-releasing hormone (TRH) stimulation test on Days 1 and 3. Serum prolactin (PRL) and TSH levels in the LC group tended to be much lower than those of the OC group during the test period. Serum PRL and TSH release response to TRH in the OC group were much higher than in the LC group on Days 1 and 3. No significant difference was noted between the OC and LC groups in serum estradiol (E2) and cortisol levels from Day 0 to Day 5. The milk volume in the LC group was significantly less than in the OC group on Day 1. Analysis of milk specimen components revealed little difference between the OC and LC groups. These results suggested that a low-caloric diet may suppress PRL, TSH and milk secretion and may not be useful for breast-feeding.

Diet, Reducing↗