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Biomedical subjects

H Mukai

Publications and source records attributed to H Mukai.

251 records · Page 14Linked to original sources
PubMed1979

Vitamin B2 activity of 7,8-dimethyl-10-(2,3,4-trihydroxy-4-formylbutyl)isoalloxazine in Lactobacillus casei.

The microbial activities of vitamin B2-aldehyde and vitamin B2-acid, produced by Schizophyllum commune, a Basidiomycete, were studied. Lactobacillus casei ATCC No. 7469 was used as a test microorganism. B2-aldehyde exhibited a good response curve in the growth of L. casei. B2-acid had neither a stimulatory nor an inhibitory effect on the growth. When B2-aldehyde was incubated with the homogenate of L. casei, it was converted to riboflavin. The flavin formed from B2-aldehyde by the homogenate not only exhibited an equivalent response curve to authentic riboflavin in the growth of L. casei, but also showed the same Rf value as authentic riboflavin in any paper chromatogram, as far as tested. Hence, the microbial activity of B2-aldehyde for L. casei seems to be ascribable to riboflavin which is a reduction product of B2-aldehyde.

Dose-Response Relationship, Drug↗
PubMed1978

Determination of total and direct bilirubins in serum with sodium dodecyl sulfate as an accelerator.

A new method for the determination of total and conjugated bilirubins in serum with use of sodium dodecyl sulfate (SDS) is described. In the presence of SDS, the reaction of bilirubin with diazotized sulfanilic acid proceeded smoothly and was completed within 15 min at room temperature, thus resulting in a clear solution having a maximal absorbance at 565 nm which was linear up to a level of 200 mg/l bilirubin concentration. The advantages of this method are: (1) a clear reaction mixture results in any case; (2) the result is not affected by hemolysis, lipemic and turbid sera. The proposed method offers a new general application for the measurement of total and conjugated bilirubins in serum.

Ascorbic Acid↗
PubMed1977

Comparative studies on the structure of reproductive organs of four botryllid ascidians.

Reproductive organs of four botryllid ascidians, Botryllus primigenus, Botryllus schlosseri, Botrylloides violaceus and Botrylloides leachi, were studied histologically. In every species, the egg follicle consisting of an egg and its inner and outer follicles, is attached to the follicle stalk, the vesicle being composed of a flat epithelium, which in its turn is connected to the atrial epithelium or to the brood pouch specialized from it. In B. schlosseri, the egg is ovulated into the atrial cavity and remains there held by the brood cup, of which the inner epithelium is derived from the follicle stalk and the outer one from the atrial epithelium. In B. primigenus, the brood pouch develops as a diverticulum of the atrial cavity, around the entrance of which a fold differentiates from the atrial epithelium and closes the pouch during embryogenesis. In both species of Botrylloides, the brood pouch is formed by the outgrowth of the thickened atrial epithelium into the blood space, the entrance of which is closed during embryogenesis. The discarded outer follicle completely disintegrates soon after ovulation in B. schlosseri, but part of it remains throughout embryogenesis in the blood space in B. primigenus or projecting into the interior of the brood pouch in Botrylloides. In primigenus, the testis, when it accompanies the egg follicle, is placed at the bottom of the brood pouch and the sperm is shed through the pouch prior to ovulation. In B. schlosseri and the Botrylloides species, the testis is located independently from the egg follicle and the sperm matures after ovulation.

Animals↗
PubMed1976

Studies on the formation of germ cells in a compound ascidian Botryllus primigenus Oka.

Gametogenesis of a compound ascidian Botryllus primigenus was studied histologically. On either side of the zooid (stage 9), in the gonadal space between the epidermis and the atrial epithelium, either a single testis or a complex of an egg follicle and a testis can be formed. The egg follicle consists of a single ovum (occasionally two ova) and its accessory cells and is connected with the atrial epithelium by the follicle stalk. The eff follicle is always accompanied by the brood pouch, a diverticulum of the atrial cavity. The testis is equipped with a vestigial spermiduct and is attached to the atrial epithelium. Buds of stage 8 comprise, besides the developing testes and egg follicles, loose aggregations of hemoblasts and oocytes of early developmental stages, which are already accompanied by primary follicular cells. Both the oocytes and the primary follicular cells seem to arise from the hemoblasts. The young oocytes are isolated in the gonadal space of the buds and are transferred to buds of the succeeding generations until they finally mature. In the bud of stage 3, a compact mass of cells appears, attaching to the inner vesicle on either side of the body. It is derived from the hemoblasts lodged there in the preceding generation and presumably also from the circulating hemoblasts. When the cell mass receives a large oocyte derived from the preceding generation, part of the cell mass differentiates into egg envelopes, forming an egg follicle, and a follicle stalk and the remainder into a testis. When the cell mass receives no oocyte, it differentiates as a whole into a testis. In the egg follicle thus formed, the outer and inner follicular cells increase in number by mitotic division. Subsequently, initial test cells are derived from the inner follicle by migration across the developing chorion; then they increase in number by mitosis. In the testis, meiosis and spermiogenesis take place.

Animals↗
PubMedDate not supplied

Antagonism by GRP(18-27) and substance P analogues on insulin release stimulated by GRP(18-27).

The antagonistic effects of [D-Phe25]gastrin-releasing peptide (GRP)(18-27) and [D-Arg1,D-Pro2,D-Trp7,9,Leu11]substance P (SP) on the stimulation of insulin release by GRP(18-27) from isolated canine pancreas were compared with that of [Ala23]GRP(18-27). The stimulation of insulin release by 1 nM GRP(18-27) was reduced to 24.1% and 15.4% by the prior infusion of 1 microM of [D-Arg1,D-Pro2,D-Trp7,9,Leu11]SP and 10 microM of [D-Phe25]GRP(18-27), respectively. Glucagon release by GRP(18-27) was not affected by these peptides using the above concentrations. The results indicate that these peptides are antagonists of bombesin-like peptide receptors on pancreatic B-cells, although the inhibitory activities are lower than that of [Ala23]GRP(18-27).

Amino Acid Sequence↗
PubMedDate not supplied

The diagnosis of pancreatic cancer by endoscopic ultrasonography.

Endoscopic ultrasonography was evaluated for detection of tumors of the pancreas. The technique was performed in 42 patients with cancer of the pancreas and 8 patients with nodular fibrosis of chronic pancreatitis. The lesions were clearly identified in all 50 patients, even when the size of the tumor was less than 20 mm in diameter. A tumor of the pancreas was usually visualized as a hypoechoic mass that had a characteristic image depending on the size. Ultrasonographic differentiation of malignant from benign tumors of the pancreas was possible in tumors larger than 30 mm in size but difficult in tumors less than 20 mm in size. Compared with conventional ultrasonography, endoscopic retrograde pancreatography, computed tomography, and angiography, endoscopic ultrasonography had the highest detection rate of tumors of the pancreas, especially in cases of small tumors under 20 mm in size. In cancer of the pancreas, endoscopic ultrasonography also proved to be valuable for the detection of vascular invasion.

Angiography↗
PubMedDate not supplied

Evaluation of endoscopic ultrasonography in the pre-operative staging of carcinoma of the ampulla of Vater and common bile duct.

Endoscopic ultrasonography (EUS) was performed in 23 patients with carcinoma of the ampulla of Vater (ampulla) and in 16 patients with common bile duct (CBD) carcinoma. These patients all underwent surgery. The layered structures of the duodenum, ampulla, and CBD, and the pancreas, portal vein, and regional lymph nodes were clearly identified by EUS using a transduodenal approach. With this technique, ampullary carcinoma appeared as a hypoechoic mass in 22 of 23 patients, and the 1 remaining cancer was not detected because of its small size. Carcinoma of the CBD also appeared as a hypoechoic mass in 12 of 16 patients. However, the remaining four appeared as hyperechoic masses. For these tumors, EUS had a high tumor detection rate (96 to 100%). In this regard, EUS was comparable to ERCP and was better than ultrasonography (US), CT, and angiography. Using EUS, we were also able to stage the extent of these tumors according to the involvement of the duodenal or CBD walls, invasion of the pancreas and portal vein, and spread to regional lymph nodes. The accuracy rates of cancer extent by EUS were 78% for ampullary carcinoma and 81% for CBD carcinoma when compared with surgical findings. We conclude that EUS is a valuable method for the detection and staging of tumors of the ampulla and CBD.

Ampulla of Vater↗
PubMedDate not supplied

Role of renal dopaminergic activity on renal sodium-water metabolism in congestive heart failure.

1. The role of the renal dopaminergic system in water-sodium metabolism in heart failure remains unclear. 2. In this study, the urinary free dopamine excretion (uDA), delivery of L-dopa to renal proximal tubules (plasma L-dopa x creatinine clearance (Ccr)), and the production of dopamine in the kidney [uDA/(plasma L-dopa x Ccr)] were investigated in patients with congestive heart failure (n = 30) and in normal controls (n = 12). In both groups, endogenous Ccr, urinary excretion of sodium (UNaV), fractional excretion of sodium (FENa), plasma noradrenaline concentration (pNA) and plasma L-dopa concentration were also estimated. 3. uDA, plasma L-dopa, delivery of L-dopa and dopamine production in the kidney showed successively lower values in congestive heart failure with progression in NYHA functional class. 4. UNaV (r = 0.458, P < 0.05) and Ccr (r = 0.539, P < 0.01) positively correlated with uDA. Linear correlations were found between left ventricular ejection fraction and uDA (r = 0.574, P < 0.01), pNA (r = -0.495, P < 0.01) or plasma L-dopa (r = 0.423, P < 0.05). 5. From these findings, it was suggested that (i) uDA was clearly suppressed in patients with CHF, and (ii) the possible mechanisms of its suppression might be due to decrease of delivery of L-dopa into the proximal tubules and suppressed production of dopamine from L-dopa in the kidney.

Adult↗
PubMedDate not supplied

A case of sclerosing hemangioma of the lung: correlation of MR images with pathological findings.

The authors present a case of sclerosing hemangioma of the lung in which MRI was performed. The tumor had areas of various signal intensities on both T1- and T2-weighted images, including high-intensity areas and isointensity areas relative to muscle. We compared the signal intensity of the tumor with its pathological findings. The relatively high signal intensity of the tumor on T1-weighted images was thought to be a reflection of lipids of clear cells, and the isointensity relative to muscle on T1-weighted images to be a reflection of fibrosis. Hyperintensity was also seen on both T1- and T2-weighted images, and was intralesional hemorrhage. Use of Gd-DTPA strongly enhanced the tumor. This enhancement was thought to be abundant blood cavities, since not many capillaries were seen in the specimen. The signal intensity of the tumor corresponded closely to the pathognomonic findings, and it is thought that MRI may be helpful in diagnosing sclerosing hemangioma of the lung because of its high contrast resolution.

Contrast Media↗
PubMedDate not supplied

Estimation of the kinetics of iodized oil injected into the feeding artery of hepatocellular carcinoma using dynamic computed tomography.

The distribution of iodized oil (Lipiodol) after its injection in hepatocellular carcinoma (HCC) was evaluated by dynamic computed tomography (CT) in 10 patients. Following the injection of Lipiodol into the hepatic artery, two patterns were observed. In type I (4/10 tumors) Lipiodol retention began at the tumor periphery and then spread contiguously towards the central portion. In type II (6/10 tumors), the accumulation began at the periphery, but then skipped directly to the central portion of the tumor. Hypervascular tumors were predominantly type I, and avascular or hypovascular tumors were all type II. This difference in Lipiodol kinetics suggests that lipid-based intra-arterial (i.a.) chemoembolization should precede the i.a. infusion of water-soluble chemotherapeutic agents or injection of solid embolic materials in hypervascular tumors.

Aged↗