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Biomedical subjects

I Tanaka

Publications and source records attributed to I Tanaka.

At least 469 records · Page 26Linked to original sources
PubMed1986

Crystallization of Bowman-Birk type protease inhibitor (peanut) and its complex with trypsin.

Crystallization and preliminary crystallographic study of Bowman-Birk type protease inhibitors, A-I, A-II, and B-III from peanut seeds (Arachis hypogaea), and of the A-II + trypsin complex were carried out. A-II, with 70 amino acid residues, crystallizes in a trigonal system, P3(1)21 (or P3(2)21), a = 71.8, c = 65.9 A, Z = 12 or 18. The A-I crystal is isomorphous with that of A-II, indicating that the N-terminal residues are in a disordered state in both crystals. The B-III crystal is monoclinic, C2, a = 119.6, b = 69.6, c = 94.2 A, beta = 115.1 degrees, Z is about 40. The A-II + trypsin complex crystallizes in an orthorhombic system, P2(1)2(1)2(1), a = 55.5, b = 56.0, c = 182.1 A, Z = 4.

Arachis↗
PubMed1986

Structure of the trypsin-binding domain of Bowman-Birk type protease inhibitor and its interaction with trypsin.

The crystal structure of the complex formed by bovine trypsin and Bowman-Birk type protease inhibitor AB-I extracted from azuki beans (Vigna angularis) 'Takara' has been analyzed. The structure was solved by the application of the phase combination of single isomorphous phases and trypsin model phases, followed by phase improvement using the iterative Fourier technique. From the resulting electron density map, a three-dimensional atomic model of the trypsin binding domain of AB-I has been built. The peptide chain at the trypsin reactive site turns back sharply at Pro29 and forms a 9-residue ring (Cys24-Cys32). The 'front side' of this ring, consisting of the reactive site (Cys24-Met28), interacts with trypsin in a similar manner to other families of inhibitors and forms a stable complex, which seems to be maintained by the interactions with the 'back side' of this ring (Pro29-Cys34). The similar spatial arrangements of the 'back side' of this inhibitor and the 'secondary contact region' of the other inhibitors with respect to the reactive site suggest an important common role of these regions in exhibiting inhibitory activity.

Chemical Phenomena↗
PubMed1986

Increased concentration of plasma immunoreactive atrial natriuretic factor in Dahl salt sensitive rats with sodium chloride-induced hypertension.

In order to determine whether there is a relationship between genetically determined salt-induced hypertension and atrial natriuretic factor (ANF), a radio-immunoassay for ANF was applied to the determination of immunoreactive ANF in plasma, atrium, hypothalamus and pons of Dahl salt-sensitive (S) and -resistant (R) rats which were fed high- or low-salt diet for 7 weeks. A twofold higher concentration of plasma ANF was observed in high-salt S rats, which developed hypertension, compared with low-salt S rats or R rats on high or low salt, which were normotensive. No significant difference was seen in atrial concentrations of ANF between S and R rats. The brain ANF concentration of the high-salt group was lower than that of the low-salt group in both S and R rats. It is proposed that the elevation of plasma ANF in the hypertensive rats may reflect a compensatory mechanism induced by volume expansion in the salt-fed S rats.

Animals↗
PubMed1986

Sodium loading and posture modulate human atrial natriuretic factor plasma levels.

Atrial natriuretic factor is postulated to act through atrial stretch receptors as a volume regulatory hormone that stimulates diuresis and natriuresis in response to increased atrial pressure. To characterize the stimuli associated with the release of atrial natriuretic factor in humans, we studied 14 normal subjects, both in the supine position and after 10 minutes in an upright posture, while they were on a regular diet (Day 0) and during 3 days of supplemental sodium chloride intake (8 g/day). Radioimmunoassay of plasma atrial natriuretic factor was performed with rabbit antibody to the human hormone amino acids (102-126). Urinary sodium excretion increased from 111 +/- 13 mEq/day (mean +/- SEM) on Day 0 to 275 +/- 15 mEq/day by the third day (Day 3) of high sodium intake. The level of atrial natriuretic factor in the supine position rose from 17 +/- 4 pg/ml (Day 0) to 76 +/- 13 pg/ml on Day 3 (p less than 0.001) and after 10 minutes in an upright posture on Day 3, the level fell to 32 +/- 10 (p less than 0.005). Plasma concentrations of atrial natriuretic factor correlated positively with spot and 24-hour urinary sodium excretion and weight gain, and correlated negatively with plasma aldosterone and renin activity. We conclude that the response of atrial natriuretic factor to sodium loading and posture change in humans is appropriate for a volume regulatory hormone.

Adult↗
PubMed1986

The storage form of renin in renin granules from rat kidney cortex.

Renin granules were partially purified from rat kidney cortex, and a storage form of renin in the granules was examined. Renin granules were isolated by discontinuous Percoll density gradient centrifugation followed by continuous Percoll density gradient centrifugation. The partially purified fraction was free from mitochondria and microsomes, as judged by the absence of marker enzymes of these organelles, but contained some lysosomal enzyme activities. The specific renin activity was 0.58 mg angiotensin I/hr/mg protein, 500 times as active as the original homogenate. Immunochemical staining with specific antisera against rat kidney renin revealed that about 10% of the granules recovered in the partially purified fractions were stained strongly. The stored renin was not activated either by acidification or by trypsin treatment, indicating that stored renin was in the fully active form. By sodium dodecyl sulfate gel electrophoresis, the stored renin had two different molecular weights, 38,000 and 36,000, and these molecular weights were not reduced by dithiothreitol or 2-mercaptoethanol, suggesting that these renins are single-chain types as opposed to the two-chain type found in male mouse submaxillary gland. These results suggest that active renins with two different molecular weights may be released from renin granules of juxtaglomerular cells.

Animals↗
PubMed1986

Radioimmunoassay for insulin-like growth factor I (IGF-I) using biosynthetic IGF-I.

We produced antiserum to insulin-like growth factor I (IGF-I), and developed a specific and sensitive radioimmunoassay (RIA) for IGF-I using the biosynthetic IGF-I. This antiserum to IGF-I was specific for IGF-I; no cross-reactivities with multiplication stimulating activity, porcine insulin or human growth hormone (hGH) were detected. The sensitivity was 10-25 pg/tube with 50% displacement at 125 pg/tube. The intra- and inter-assay coefficients of variation for IGF-I were 5.4 and 9.7%, respectively. The plasma IGF-I levels as determined by RIA in normal adults (N = 46), patients with active acromegaly (N = 31), and pituitary dwarfs (N = 31) were 21.6 +/- 1.0, 157.3 +/- 17.0, and 2.5 +/- 0.3 ng/ml (Mean +/- SEM), respectively, indicating the levels were GH-dependent. The plasma IGF-I levels were significantly increased from 2.2 +/- 0.2 to 26.5 +/- 3.2 ng/ml after hGH administrations for three consecutive days in five pituitary dwarfs. The IGF-I levels were low in patients with hypothyroidism and liver cirrhosis, but were normal in patients with chronic renal failure. These data confirm previous reports and this radioimmunoassay proves useful in evaluating plasma IGF-I levels.

Acromegaly↗
PubMed1986

Alterations in atrial and plasma atrial natriuretic factor (ANF) content during development of hypoxia-induced pulmonary hypertension in the rat.

Distension of the atrial wall has been proposed as a signal for the increased release of atrial natriuretic factor (ANF) from atrial myocytes in response to perceived volume overload. To determine whether pressure changes resulting from hypertension in the pulmonary circulation may stimulate release of ANF, rats were exposed to chronic hypobaric hypoxia for 3 or 21 days and the ANF concentration in the atria and plasma were determined by specific radioimmunoassay. Exposure to chronic hypoxia resulted in significant increases in hematocrit at both 3 (p less than 0.025) and 21 days (p less than 0.005) and in the development of right ventricular hypertrophy (RVH) expressed as the ratio of the weight of the right ventricle to the weight of the left ventricle and septum (RV/LV+S) at both 3 (RV/LV+S = 0.278 +/- 0.005) and 21 days (RV/LV+S = 0.536 +/- 0.021). After 21 days, left atrial (LA) ANF content was significantly increased in hypoxic rats compared to controls (508 +/- 70 ng/mg tissue vs 302 +/- 37 ng/mg), while right atrial (RA) ANF content was significantly reduced (440 +/- 45 vs 601 +/- 58 ng/mg). At this time, plasma ANF concentration was significantly elevated compared to controls (238 +/- 107 pg/ml vs 101 +/- 10 pg/ml). These results suggest that the development of pulmonary hypertension following chronic hypobaric exposure induces altered atrial ANF content and increased plasma ANF concentration as a result of altered distension of the atrial wall.

Animals↗
PubMed1986

[Malignant paraganglioma of the peri-iliac artery].

A malignant nonfunctioning paraganglioma of the pelvic retroperitoneum (left external iliac artery) with metastases to the femoral lymph nodes was found in a 68-year-old woman at exploratory laparotomy. Light microscopy showed a typical alveolar pattern with fine vascular stroma. The tumor cells had finely granular eosinophilic cytoplasm and oval to round nuclei with pleomorphism and mitotic figures, Grimelius stain showed no argyrophilic granules, but S 100 protein was demonstrated in the cytoplasm by the PAP method of Sternberger. Formaling fixed tissues were examination by electron microscopy, and dense core granules consistent with neurosecretory granules were found in the cytoplasm of some tumor cells.

Aged↗
PubMed1986

A case of pneumocytoma (so-called sclerosing hemangioma) with lymph node metastasis.

A case of "sclerosing hemangioma" (pneumocytoma) of the lung with lymph node metastasis is reported. A 22-year-old Japanese man was found to have a well-defined round lesion in the right lung (S7), which increased in size slightly during a 2-year follow-up period. He underwent right lower lobectomy with a preoperative diagnosis of a benign lung tumor. The pulmonary tumor revealed histological features characteristic of "sclerosing hemangioma" of the lung, in addition to which there were many large polygonal foamy cells, forming tubular or papillary structures. These cells were found by electron microscopy to contain numerous cytoplasmic lamellar bodies and showed a positive reaction with anti-surfactant apoprotein antibody immunohistochemically. Therefore, they were considered to be cells differentiating toward type II pneumocytes. Review of 21 typical "sclerosing hemangiomas" disclosed a few or some such foamy cells in 10 cases. A single hilar lymph node was the site of microscopic metastases, which consisted of "large clear foamy cells" and smaller polygonal or round cells with slightly eosinophilic cytoplasm, both of which were components of the pulmonary "sclerosing hemangioma." This case supports the theory that "sclerosing hemangioma" is a neoplasm of type II pneumocyte lineage. Although it is said to be benign, rare cases apparently show metastatic potential.

Adult↗
PubMed1986

Pharmacological profiles of 2-carboxyphenyl-1-(4-chlorobenzoyl)-5-methoxy-2-methylindole-3-acetate and 2-[(2-carboxyphenoxy)-carbonyl]phenyl-1-(4-chlorobenzoyl)-5-meth oxy-2- methylindole-3-acetate, new antiinflammatory agents.

When the effects of new antiinflammatory drugs, 2-carboxyphenyl-1-(4-chlorobenzoyl)-5-methoxy-2-methyl-indole-3-acetate (TB 219) and 2-[(2-carboxyphenoxy)carbonyl]phenyl-1-(4-chlorobenzoyl)-5- methoxy-2-methylindole-3-acetate (TB 220), were investigated in various experiments, the following results were obtained: 1. TB 219 and TB 220 showed remarkable inhibitory effects on carrageenin edema, ultraviolet erythema and adjuvant arthritis. Although TB 219 displayed almost equipotent or slightly more potent effect than those of indometacin and acemetacin, TB 220 was slightly less effective than these two reference drugs except for the therapeutic effect on adjuvant arthritis. 2. TB 219 and TB 220 inhibited the writhing syndrome induced by acetic acid and inflammatory hyperesthesia, and they provided a significant antipyretic activity. 3. Both drugs elicited almost negligible side effects in the gastrointestinal tract even after the repeated administrations. Especially, ulcerogenic activity of TB 220 was extremely weak. LD50's of both drugs are higher than that of indometacin in rats. 4. Both drugs elicited no appreciable changes in general behavior in mice and rats after oral administration. After intraperitoneal or intravenous injection of these two drugs, no marked changes in spontaneous EEG pattern and the spinal reflex were observed.

Animals↗
PubMed1986

[Clinical effects of TA-077 in non-Hodgkin's lymphomas].

Ten patients with non-Hodgkin's lymphomas (NHL), six untreated and four with previous chemotherapy, were treated with TA-077, a new derivative of nitrosourea. Partial remission was observed in three untreated cases (30%) of NHL [Case 1: 71-year-old female with B cell lymphoma/diffuse small cell type, Case 2: 79-year-old male with T cell lymphoma/diffuse large cell type, and Case 3: 64-year-old female with adult T cell leukemia lymphoma (ATLL)]. Remission durations were as follows: Case 1; 33 days, Case 2; 38 days and Case 3; 14 days. Side effects were transient anorexia (40%), nausea & vomiting (30%), liver dysfunction (10%) and delayed hematological toxicities (80%). Hematological toxicities consisted of leukocytopenia (80%), thrombocytopenia (60%) and anemia (20%). Our study suggests that TA-077 is a useful agent as one of the drugs used in combination chemotherapy against NHL, since it was effective for refractory T cell malignancies such as ATLL.

Adult↗