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Biomedical subjects

T Kurosawa

Publications and source records attributed to T Kurosawa.

At least 109 records · Page 6Linked to original sources
PubMed1994

Monoclonal antibodies specific for 18-hydroxycortisol and their use in an enzyme immunoassay for human urinary 18-hydroxycortisol for diagnosis of primary aldosteronism.

We report the development of a monoclonal antibody-based enzyme immunoassay (EIA) specific for human urinary 18-hydroxycortisol, a biological marker of primary aldosteronism. Hybrid cell lines (hybridomas) were isolated after fusion between myeloma cells and spleen cells prepared from mice immunized with 18-hydroxycortisol conjugate. A competitive EIA suitable for the measurement of urinary 18-hydroxycortisol was developed using the mouse monoclonal antibody, KTM-41, which showed no practical cross-reaction with related endogenous steroids and synthetic steroids. This EIA meets all the requirements of routine clinical assay in terms of sensitivity (detection limit: 20 nmol/L), reproducibility (total CV: 8-15%), accuracy (recovery: 88-115%), simplicity and rapidity (< 3 h). Urinary 18-hydroxycortisol measured by the present assay was 153 +/- 119 nmol/L (mean +/- SD, range, 28-485) and 1787 +/- 1180 (range, 810-4264) in normal subjects (n = 20) and in patients with primary aldosteronism (n = 7), respectively. Clinical validation of the assay was confirmed by an appropriate decrease in urinary 18-hydroxycortisol level in patients with primary aldosteronism subsequent to adrenalectomy: 171 +/- 141 nmol/L (range, 41-466).

Animals↗
PubMed1994

[Pathogenesis of spontaneous nephrosis in mice--urinary protein in nephrotic mice].

There is a paucity of model animals for naturally occurring nephrosis. The nephrotic mouse strain (ICGN) found from ICR mouse colony at National Institute of Health could be one of the most suitable model for nephrosis. We maintained the strain of mice which was originated from the hybrid between the nephrotic ICGN mice and ICR mice. Nephrosis is diagnosed with the presence of albumin band on SDS-PAGE of the urine. The detection of urinary albumin using SDS-PAGE could be valuable for early diagnosis of nephrosis in the mice. The total urinary protein concentration was determined on the course of nephrosis. The nephrotic mice showed slightly higher protein concentration between 2 and 6 days old as compared to control mice. Until 16 day old, it was maintained relatively low level. Thereafter, the total urinary protein increased gradually. However the diagnosis of nephrosis with total urinary protein alone may be limited due to the major urinary protein which can be detected even in normal rodents.

Albuminuria↗
PubMed1994

Inhibitory effect of simultaneous intraportal administration of 5-fluorouracil, uracil and degradable starch microspheres on experimental hepatic micrometastasis, is of colon cancer.

This study was designed to examine the optimal regimen of 5-fluorouracil (5-FU), uracil and degradable starch microspheres (DSM) to prevent the hepatic metastasis of colorectal cancer. BALB/C mice were used as a model of hepatic micrometastasis of mouse transplantable colorectal cancer, Colon 26. We intraportally administered to the mice 5-FU at a dose of 34.8 mg/kg body weight; uracil at the dose equal to, or 8 times higher than that of 5-FU in molar weight and DMS at a dose of 5 mg/kg body weight. We investigated the hepatic and serum concentrations of 5-FU and uracil and the inhibitory effect of various combinations of the three substances on hepatic metastasis. The study showed that concurrent use of 5-FU with uracil at a dose 8 times higher than that of 5-Fu could keep 5-FU concentration high in hepatic tissue and relatively low in serum. This tendency became more marked with the presence of DSM. These findings support the previous study results that uracil antagonizes breakdown of 5-FU in the liver and with the aid of DSM, retards excretion of 5-FU from the liver. Further investigations for clinical application of this method will lower the incidence of hepatic metastasis of colorectal cancer.

Animals↗
PubMed1994

Identification of (24E)-3 alpha,7 alpha-dihydroxy-5 beta-cholest-24-enoic acid and (24R,25S)-3 alpha,7 alpha,24-trihydroxy-5 beta-cholestanoic acid as intermediates in the conversion of 3 alpha,7 alpha-dihydroxy-5 beta-cholestanoic acid to chenodeoxycholic acid in rat liver homogenates.

Studies of chemical structure of the intermediates in the biosynthetic sequence between 3 alpha,7 alpha-dihydroxy-5 beta-cholestanoic acid (DHCA) and chenodeoxycholic acid have been undertaken. Radiolabeled DHCA was incubated with a rat liver preparation. The reaction products were converted to the p-bromophenacyl esters, and analyzed by reversed-phase high performance liquid chromatography. Under the conditions used, the radioactivity was found in (24E)-3 alpha,7 alpha-dihydroxy-5 beta-cholest-24-enoic acid (31%) and (24R,25S)-3 alpha,7 alpha,24-trihydroxy-5 beta-cholestanoic acid (7%) along with the starting material (62%). Neither the 24Z isomer of the alpha,beta-unsaturated bile acid nor the other three isomers of the beta-hydroxy bile acid were detected. The findings support the proposed pathway for the side chain cleavage in chenodeoxycholic acid biosynthesis, which is thought to be identical to that of cholic acid biosynthesis.

Animals↗
PubMed1993

Determination of urinary 18-hydroxycortisol by isocratic normal-phase high-performance liquid chromatography.

A method for the determination of urinary 18-hydroxycortisol by high-performance liquid chromatography is described. Urinary samples were first mixed with an internal standard, 18-hydroxyprednisolone. 18-Hydroxycortisol and 18-hydroxyprednisolone, extracted by a Bond Elut column, were dehydrated by 1% (w/v) p-toluenesulphonic acid to the 11,18-epoxides. The epoxides were separated into two distinct peaks on a Resolve Silica column with a mobile phase of chloroform-methanol (100:2.5, v/v). The detection wavelength was 248 nm. The urinary 18-hydroxycortisol concentration was calculated from peak-height ratio of 11,18-epoxycortisol to 11,18-epoxyprednisolone. The linearity of the ratio was satisfactory in the range 12.5-300 ng per injection of 11,18-epoxycortisol. A specific increase of urinary 18-hydroxycortisol in patients with primary aldosteronism was demonstrated.

Chromatography, High Pressure Liquid↗
PubMed1993

Sporogony of Theileria sergenti in the salivary glands of the tick vector Haemaphysalis longicornis.

Sporogony of Theileria sergenti in the salivary glands of the tick vector Haemaphysalis longicornis was observed by light and transmission electron microscopy. Fission bodies that developed from kinetes were observed as masses (approximately 32 x 15 microns) that occupied half of the acinous cell at 2 days after the infestation of ticks. Parasites possessed an irregular nucleus of low electron density, highly electron-dense granules, and mitochondrion-like bodies in the cytoplasm. Parasites developed into a multinucleate syncytium, increasing in size and complexity. Subsequently, the nuclei of parasites became round and highly electron-dense, and tubelike structures and rhoptries as precursors of the highly electron-dense granules appeared in the cytoplasm. Approximately 40,000 sporozoites arose via radial budding from the syncytium that had developed from kinetes. As in T. parva, no evidence of discrete secondary or tertiary sporoblasts was found in T. sergenti. The sporogony of T. sergenti was extremely similar to that of T. parva.

Animals↗
PubMed1993

Theileria sergenti infection in the Bo-RBC-SCID mouse model.

We have previously developed the Bo-RBC-SCID mouse model for Theileria sergenti infection. In the present study, this model was further examined to delineate the models of parasite infection. The Bo-RBC-SCID mice were prepared by periodically transfusing uninfected bovine erythrocytes (Bo-RBCs) into splenectomized SCID mice via the intraperitoneal (i.p.) route. The mice, separated into three groups, were inoculated i.p., intravenously (i.v.), or subcutaneously (s.c.) with T. sergenti-infected Bo-RBCs. Examination of samples of peripheral blood demonstrated that the parasite infected mice inoculated via any one of the three routes. The mice inoculated i.v., however, developed parasitemia earlier than those inoculated i.p. or s.c. When Bo-RBC-SCID mice prepared without splenectomy were infected with T. sergenti, a high-level parasitemia appeared only once. After that, not only the level of parasitemia but also the number of Bo-RBCs in the peripheral blood rapidly decreased despite the continuation of Bo-RBC transfusions. The results suggest that T. sergenti proliferates primarily in the circulating blood in Bo-RBC-SCID mice and that in response to the parasites growth, the spleen may play an important role in the removal of both parasitized and unparasitized Bo-RBCs from the blood circulation.

Animals↗
PubMed1993

The Bo-RBC-SCID mouse model for evaluating the efficacy of anti-theilerial drugs.

We have previously developed a mouse model which allowed the proliferation of Theileria sergenti in severe combined immunodeficiency (SCID) mice with circulating bovine erythrocytes (Bo-RBC). In the present study, this model was utilized to test the efficacy of anti-theilerial drugs. Bo-RBC-SCID mice were created by giving periodic transfusions of T. sergenti-free Bo-RBC, and subsequently infecting with T. sergenti. Three anti-protozoal compounds, Pamaquine (Yamanouchi Pharmaceutical Co. Ltd), Ganaseg (Japan CIBA-GEIGY Ltd) and Buparvaquone (Coopers Animal Health Ltd), were subcutaneously administered into the mice at doses recommended for cattle therapy. Blood examinations demonstrated that all three drugs significantly reduced the level of parasitemia although Ganaseg was effective only at a dose five times higher than that recommended for cattle therapy. Administration of the drugs neither caused any sign of acute toxicity nor changed the rate of Bo-RBC in the SCID mice's circulating blood cells. The results indicate that the Bo-RBC-SCID mouse model may offer a useful in vivo system for evaluating the efficacy of anti-protozoal drugs against T. sergenti.

Aminoquinolines↗
PubMed1993

An efficient synthesis of 4 beta- and 6 alpha-hydroxylated bile acids.

An efficient method for the preparation of 4 beta- and 6 alpha-hydroxylated bile acids has been developed. It involved a highly stereoselective acetoxylation at the 4 beta and 6 alpha positions of 3- and 7-oxo bile acids, respectively, with lead tetraacetate in the presence of boron trifluoride etherate in acetic acid. Reduction of the resulting alpha-acetoxy ketones with sodium borohydride or tert-butylamine borane complex, and alkaline hydrolysis, provided the desired bile acids in good yields.

Acetates↗
PubMed1993

A direct enzyme immunoassay for 18-hydroxycortisol in urine: a new tool for screening primary aldosteronism.

A microplate enzyme immunoassay has been developed for the measurement of 18-hydroxycortisol in urine. An antiserum was produced by immunization of rabbits with a 3-O-(carboxymethyl)oximino-18-hydroxycortisol-bovine serum albumin conjugate. IgG was isolated from the antiserum and was biotinylated. Newly synthesized p-nitrophenyl ester of the oxime was used for the preparation of steroid-horseradish peroxidase conjugate. After an incubation of diluted urine samples (or standards) and the steroid-enzyme conjugate with the biotinylated antibody, the resulting antigen-antibody complex was separated by adding a portion of the reaction mixture into the avidin-coated microtiter plate. Peroxidase bound to solid phase was measured colorimetrically. The standard curve was linear from 0.25 to 10 ng/well. Intra- and interassay coefficients of variation were 5.5-8.8 and 7.8-8.2%, respectively. The assay was specific except for 18-hydroxycortisone with minor cross reaction. Urinary 18-hydroxycortisol excretion ranged 836-7460 and 26-696 nmol/24 h, respectively, in patients with primary aldosteronism (n = 8) and in control subjects (n = 40). This simple and rapid (< 4 h) assay is suitable for screening patients with primary aldosteronism.

Animals↗
PubMed1993

The detection of a mutation of CD18 gene in bovine leukocyte adhesion deficiency (BLAD).

Two calves (5 and 9 months old) affected with pneumonia and gingivitis were also diagnosed as having bovine leukocyte adhesion deficiency (BLAD). The gene of leukocyte adhesion molecule CD18 in these BLAD calves and their dams (carrier) were examined by means of polymerase chain reaction (PCR) and digestion of restriction endonuclease. The splicing in mRNA coded CD18 reported in human LAD was not recognized in BLAD on the basis of the results of PCR amplification. The region including the portion of point mutation, which corresponded to the region reported in the human patient, was amplified by PCR, and the PCR product was then digested with Taql. An obvious difference was recognized in the pattern of digestion among healthy calves, BLAD calves and their dams. In BLAD, therefore, the point mutation reported in human patients was strongly suggested. Moreover it may be a method able to be used in detecting the carrier.

Animals↗
PubMed1993

Light and electron-microscopical observations of the early developmental stages of Theileria sergenti in the gut of Haemaphysalis longicornis.

Morphological characteristics of the early developmental stages of Theileria sergenti in the vector tick were observed by light and electron-microscopies and compared with those of other Theileria species. Just before the repletion of nymphs, various stages of the parasite were observed in gut contents of tick by light microscopy: the spherical intra-erythrocytic stage, the ring-form stage, the spindle-shaped stage and the round-form stage. Electron microscopy revealed that the spherical intra-erythrocytic stages were 1-2 microns in diameter and were marginally located in host erythrocytes. The organisms liberated from host erythrocytes into the tick gut lumen had a large nucleus, an endoplasmic reticulum, electron dense-organelles and a double-walled, mitochondrion-like organelle. In addition ticks had ray-bodies in the gut lumen. These bodies had short protrusions containing 1-3 microtubules and a labyrinthine structure containing highly electron-dense organelles, so they were considered as the developing microgamont of T. sergenti.

Animals↗
PubMed1993

Comparison of plasma endotoxin levels in germ-free, SPF and conventional laboratory animals (mice and rats).

Plasma endotoxin levels were examined in laboratory mice and rats sustained under germ-free (GF), SPF and conventional (CV) conditions. The values were 1.72 (GF mouse), 2.67 (SPF mouse), 2.44 (CV mouse), 2.05 (GF rat), 2.56 (SPF rat), and 3.13 pg/ml (CV rat). The GF animals showed the lowest levels, followed by SPF and CV animals, in that order. When SPF animals were transferred into the conventional condition (conventionalization), the plasma endotoxin levels changed slightly, but not significantly. The present study demonstrates that the levels of plasma endotoxin in healthy laboratory animals are relatively stable and are not affected by microbiological conditions.

Animals↗
PubMed1993

[Invention of an air forced ventilated micro-isolation cage and rack system--environment within the cages: ventilation, air flow].

A forced air ventilation system for small laboratory animals was developed. The system consists of an air handling unit with air supply and exhaust fans, a rack, hard cage covers with a large diameter air inlet and an outlet, and shoe box cages. Air flow from the supply duct, to the exhaust duct and within the cage were observed. Variations in air flow among cages was minimal. The optimal air exchange rate of the cages in this system was determined to be 60 times per hour based on the results obtained in the present study. At this air exchange rate, air flow at the base of the cages had a velocity of less than 0.09m/sec, which was within the range of recommended values for humans. The observed results show that the system developed is capable of sustaining a laboratory animal microenvironment well in terms of air flow, without too much energy cost.

Air Movements↗
PubMed1993

[A case of adrenal myelolipoma incidentally discovered on abdominal ultrasonography].

We report a case of adrenal myelolipoma occurring in a 58-year-old-woman. A tumor was incidentally detected in the right adrenal region by ultrasonography during admission to our hospital due to gastric ulcer. Ultrasonography revealed punctate calcification within the tumor. No endocrinologic abnormalities were demonstrated. CT revealed a nonhomogenous mass 5 cm in diameter that consisted of tissue with a fatty density and areas of calcifications. Retrograde femoral angiography demonstrated that the tumor was relatively hypervascular. Large blood vessels resembled sinusoids that were demonstrated by pooling of the contrast medium. Right adrenalectomy was performed. The histological diagnosis was adrenal myelolipoma.

Abdomen↗