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Biomedical subjects

H Kuroda

Publications and source records attributed to H Kuroda.

At least 163 records · Page 9Linked to original sources
PubMed1995

Light-enhanced gene expression of NADPH-protochlorophyllide oxidoreductase in cucumber.

The NADPH-protochlorophyllide oxidoreductase (NPR) is a well known enzyme catalyzing photoconversion of protochlorophyllide to chlorophyllide a and its expression is negatively regulated by light. We cloned a NPR cDNA from cucumber (Cucumis sativus L.). The cDNA contained an open reading frame encoding 398 amino acids and amino acid sequence showed high similarity to those of NPR from other plants. Contrasting with most other plants, the levels of the NPR mRNA increased in etiolated cotyledons of cucumber when they were illuminated with continuous light, suggesting that the expression of this NPR gene was strongly related to chlorophyll synthesis in green leaves.

Amino Acid Sequence↗
PubMed1995

The positive nuclear staining observed with monoclonal antibody against PRAD1/cyclin D1 correlates with mRNA expression in mantle cell lymphoma.

Recently, we produced a monoclonal antibody, 5D4, against the PRAD1/cyclin D1 product and suggested positive nuclear staining to be associated with mantle cell lymphoma (MCL). Now we have further characterized the specificity of this antibody and studied the relation of immunohistochemical detection to PRAD1/cyclin D1 mRNA expression and DNA rearrangement. Immunofluorescence and immunoblotting studies demonstrated the 5D4 antibody to be crossreactive with cyclin D2, but not cyclin D3. On immunostaining, 15 of 19 MCL cases (79%) presented the nuclear staining pattern and PRAD1/cyclin D1 mRNA expression was detected by Northern blot analysis in 12 of 15 MCL cases studied (80%): all cases with the mRNA expression showed the nuclear staining pattern. Southern blot analysis with 11q13 BCL-1 probes detected DNA rearrangements in 8 of 19 MCL cases (42%), all 8 exhibiting PRAD1/cyclin D1 mRNA expression. In 21 lymphoma cases of types other than MCL, neither the mRNA expression nor the nuclear staining were observed, although cytoplasmic staining was often apparent. These results indicated that positive nuclear staining of lymphoma cells by 5D4 antibody reflects PRAD1/cyclin D1 mRNA expression, and showed that this monoclonal antibody has diagnostic value for differentiating MCL from other types of lymphomas.

Animals↗
PubMed1995

Smooth muscle relaxing and hypotensive activities of synthetic calciseptine and the homologous snake venom peptide FS2.

The biological activities of synthetic calciseptine and FS2, a homologous peptide from snake venom, were determined using in vitro and in vivo preparations. Calciseptine and FS2 produced dose-dependent relaxation in pre-constricted rat aorta, pulmonary artery and trachea. The onset and duration pattern of these relaxing effects were similar to those caused by nifedipine, an L-type Ca2+ channel blocker. Calciseptine relaxed the contraction of rat aorta provoked by an L-type channel agonist, Bay K 8644. This relaxation was not affected by NG-nitro-L-arginine, indomethacin or propranolol. Calciseptine and FS2 inhibited the contraction caused by acetylcholine in guinea pig ileal longitudinal muscle. In case of in vivo study using anesthetized rats, calciseptine, FS2 and nifedipine showed depressor effects. The hypotensive effects of the two peptides were more potent and sustained than that of nifedipine. These findings show that both synthetic calciseptine and FS2 have similar biological activities like nifedipine, an L-type Ca2+ channel blocker. In addition, these two peptides with large molecular weights may be unique and useful tools for studying the Ca2+ channel.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1995

[Immunological study of the postoperative adjuvant treatment with interferon gamma in patients with renal cell cancer--measurement of peripheral blood lymphocyte subsets with three color flow cytometry].

The antitumoral effects of interferon (IFN) against renal cell carcinomas (RCC) are considered to consist of a direct tumoricidal activity and an indirect action related to the host immune system. Monitoring to T lymphocytes is an immunological parameter to evaluate the antitumoral effects of IFN. To examine in detail the change of CD8 positive cells reported previously, we analyzed the change of the peripheral blood T lymphocyte subsets using three color flowcytometry during the period of IFN-gamma administration. We administered recombinant interferon gamma (rIFN-gamma) to the patients with renal cell cancer. Eighteen patients received a prophylactic injection of rIFN-gamma (300 x 10(4) units per week) after nephrectomy. Among them three patients developed distant metastases and one had local recurrence after the start of rIF-gamma therapy. We evaluated the immunological change by measurement of the peripheral blood lymphocyte subsets consisting of activated cytotoxic T lymphocytes (ACTL), activated suppressor T lymphocytes (ASTL), activated suppressor-inducer T lymphocytes (AITL), cytotoxic T lymphocytes (CTL), helper T lymphocytes (HTL), and suppressor-inducer T lymphocytes (SITL), from the start of rIFN-gamma injection. We also estimated the natural killer (NK) activity by a cytolytic test at the same points. NK activity consecutively increased throughout the period of administration of rIFN-gamma. We found significant enhancement of ACTL at the sixth month (P < 0.05), ASTL at the third month (P < 0.01) and NK activity at the second week, the first month, the third month and the sixth month (P < 0.01) after the start of rIFN-gamma injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[A case of a single coronary artery in the presence of coexistent atherosclerotic coronary artery disease].

A 57-year-old female was admitted with 6-month history of effort angina. Ascending aortography showed that the right coronary artery (RCA) did not originate from the right coronary sinus. Coronary arteriography showed that the circumflex branch (CX) continued beyond the crux into the right atrioventricular groove to supply marginal branches to the right ventricle, that is, RCA originated from the CX at the crux. RCA had the 75% stenosis near the crux. Left anterior descending branch (LAD) also had 90% stenosis at segment 6. She did not have the additional congenital cardiac anomalies, and underwent coronary artery bypass grafting to LAD and RCA without problem.

Angina Pectoris↗
PubMed1994

Immunologically cross-reactive 57 kDa and 53 kDa glycoprotein antigens of bovine milk fat globule membrane: isoforms with different N-linked sugar chains and differential glycosylation at early stages of lactation.

Two glycoprotein antigens with molecular masses of 57 kDa (MGP57) and 53 kDa (MGP53) were co-purified from bovine milk fat globule membrane (MFGM) by immunoaffinity chromatography using a monoclonal antibody raised against the MFGM. Their N-terminal sequences of 22 amino acids determined were identical, and the sequence was homologous (about 60% identical) to the deduced amino acid sequence of mouse milk fat globule epidermal growth factor (EGF) factor 8 (MFG-E8) (Ref. [12], Stubbs, J.D. et al., Proc. Natl. Acad. Sci. USA, 87, 8417-8421, 1990). This suggests that MGP57/53 are bovine MFGM components 15/16 (PAS-6 and PAS-7), which have recently been reported to be bovine homologs of MFG-E8. N-Glycanase treatment of these glycoproteins reduced their molecular masses, and consequently the enzymatically deglycosylated MGP57 and MGP53 converged on a single band of 50 kDa as measured by SDS-PAGE, indicating that the polypeptide portions of these two distinct glycoprotein antigens are very similar or identical and that their N-linked sugar chains contributed to minor difference in their molecular masses. Western blot analyses using lectins also revealed that they were differentially glycosylated; MGP57 was stained with concanavalin A (Con A) more strongly than MGP53, whereas MGP 53 was stained well with soybean agglutinin (SBA). Reactivity with SBA remarkably increased during early stages of lactation. Two-dimensional gel electrophoresis showed that MGP57 and MGP53 were electrically heterogeneous; from day 9 after parturition, both glycoproteins fell in almost the same range of isoelectric points between 6.4 and 7.6, also, such glycoproteins from day 1 after parturition were more acidic, probably due to terminal sialylation of their sugar chains.

Amino Acid Sequence↗
PubMed1994

Small lipid-soluble cations are not membrane voltage probes for Neurospora or Saccharomyces.

Small lipid-soluble cations, such as tetraphenylphosphonium (TPP+) and tetraphenylarsonium (TPA+) are frequently used as probes of membrane voltage (delta psi, or Vm) for small animal cells, organelles, and vesicles. Because much controversy has accompanied corresponding measurements on 'walled' eukaryotic cells (plants, fungi), we studied their transport and relation to Vm in the large-celled fungus Neurospora crassa-where Vm can readily be determined with microelectrodes-as well as in the most commonly used model eukaryotic cell, the yeast Saccharomyces cerevisiae. We found no reasonable conditions under which the distribution of TPP+ or TPA+, between the cytoplasm (i) and extracellular solution (o), can serve to estimate Vm, even roughly, in either of these organisms. When applied at probe concentrations (i.e., < or = 100 microM, which did not depolarize the cells nor deplete ATP), TPP+ stabilized at ratios (i/o) below 30 in both organisms. That would imply apparent Vm values positive to -90 mV, in the face of directly measured Vm values (in Neurospora) negative to -180 mV. When applied at moderate or high concentrations (1-30 mM), TPP+ and TPA+ induced several phases of depolarization and changes of membrane resistance (Rm), as well as depletion of cytoplasmic energy stores. Only the first phase depolarization, occurring within the perfusion-turnover time and accompanied by a nearly proportionate decline of Rm, could have resulted from TPP+ or TPA+ currents per se. And the implied currents were small. Repeated testing, furthermore, greatly reduced the depolarizing effects of these lipid-soluble ions, implicating an active cellular response to decrease membrane permeability.

Adenosine Triphosphate↗
PubMed1994

Cation effluxes associated with the uptake of TPP+, TPA+, and TPMP+ by Neurospora: evidence for a predominantly electroneutral influx process.

Previously observed anomalies in the transport of lipid-soluble cations (LSI's) - presumed voltage-probe ions-by intact fungal cells [1] prompted a systematic investigation of ion exchanges induced by high (millimolar) concentrations of the particular species tetraphenylphosphonium ion (TPP+), tetraphenylarsonium ion (TPA+), and triphenylmethylphosphonium ion (TPMP+). With low extracellular free Ca2+ (no calcium added to the medium), influx of the LSI's was biphasic, indicating rapid entry into the cytoplasm followed by sequestration into a subcompartment. The latter process, especially, was strongly inhibited by extracellular Ca2+ (1 mM). Contrary to the expectation for electrophoretically driven entry of LSI's into fungal cells, no major efflux of protons (acidification of the medium) could be measured; in fact, significant alkalinization of the medium was observed. The major cellular inorganic cations, K+ or Na+ (under different conditions), were released during LSI uptake, but with kinetic behavior which clearly ruled out direct coupling to the uptake of TPP+, TPA+, or TPMP+. The major mechanism for entry of these lipid-soluble cations into Neurospora appears to be electroneutral diffusion in combination with one or more hydrophilic anions. Subsequent penetration of the fungal vacuoles would result in binding of LSI's to storage polyanions (viz., polyphosphate) and concomitant displacement of the normal vacuolar cations, such as basic amino acids and polyamines, thus leading to alkalinization of the extracellular medium. The observed effluxes of cytoplasmic K+ and Na+ should result independently from energetic changes (i.e., uncoupling of the mitochondrial) and are most easily described by simple, but asynchronous, changes in the average rate constants for entry and exit of the alkali-metal cations.

Arsenicals↗
PubMed1994

Chiral separation by capillary affinity zone electrophoresis using an albumin-containing support electrolyte.

Chiral separations of some pharmaceutical compounds were studied by capillary affinity zone electrophoresis. Bovine serum albumin (BSA) was used as a chiral selector and added to electrolyte. For the chiral separation of new quinolone bactericidal reagents, phosphate buffer was more appropriate than borate buffer solution as the support electrolyte. The effects of BSA concentration, albumin type, pH, chiral additive, and voltage on separation were observed. As a result, chiral separations were performed in the pH range 7-8. The migration and stereoselectivities of enantiomers were changed by varying the protein concentration (more than 0.2% w/v) and voltage and by adding amino acids as chiral modifiers. This procedure is easily applicable to other compounds for chiral separation or for studies of protein binding interaction.

Anti-Infective Agents↗
PubMed1994

Production and characterization of monoclonal antibodies directed against bovine milk fat globule membrane (MFGM).

Nine hybridomas secreting monoclonal antibodies (mAbs) to bovine milk fat globule membrane (MFGM) were produced from spleen cells of three immunized BALB/c mice. Several MFGM antigens recognized by some mAbs were identified as a 120 kDa protein and 67 kDa (butyrophilin), 57 kDa (PAS-6), 53 kDa (PAS-7), 33 kDa glycoproteins. The other mAbs secreted by four independent hybridoma clones recognized many broad bands ranging from 20 to 200 kDa. The 120 kDa protein and 67 kDa, 57 kDa, 53 kDa glycoproteins were detected by each mAb in the plasma membrane fraction prepared from a lactating bovine mammary gland. Moreover, mammary gland epithelium of a thin section was specifically stained with these mAbs, indicating that these mAbs directed against MFGM recognized membrane proteins and glycoproteins of lactating mammary epithelial cells. Upon heating of the MFGM in phosphate buffer, pH 7.4 at 100 degrees C for 10 min, the antigens still retained most of its reactivity to these mAbs, whereas, proteolytic cleavage by trypsin and chymotrypsin strongly reduced its reactivity to these mAbs by 60% or more except for two mAbs which recognized the 57 and 53 kDa glycoproteins, respectively.

Animals↗
PubMed1994

Sperm and its soluble extract cause transient increases in intracellular calcium concentration and in membrane potential of sea urchin zygotes.

Fertilization is known to initiate a transient increase of intracellular calcium concentration and an accompanying change of membrane potential in sea urchin eggs. If the fertilization membrane and hyaline layer are removed, sperm can again enter fertilized eggs (refertilization). We have found that Ca2+ and voltage transients were repeatedly induced in fertilized eggs during refertilization. Similar changes were also obtained by external application of a soluble extract of sperm to fertilized eggs. This sperm extract caused no changes in unfertilized eggs. The active factor in the sperm extract survives heating (100 degrees C, 10 min) and incubation with pronase. Its molecular weight is less than 1300.

Animals↗
PubMed1994

Prognosis after hepatic resection in patients with hepatocellular carcinoma, estimated on the basis of the morphometric indices.

To determine whether the morphometric indices of hepatocellular carcinoma (HCC) correlated with the prognoses, the microscopic morphometric values for 84 HCC cases treated by hepatic resection were studied using an image analyzer in relation to the survival rate and the gross classification. The mean survival time (MST) was 58 months in cases with a nucleocytoplasmic area ratio (N/C) of less than 0.28; this was significantly longer than the 38-month MST in cases with an N/C of more than 0.28 (P < 0.05). In stage III disease, the MST for cases with an N/C of less than 0.28 was 63 months, which was significantly longer than the MST of 13 months for cases with an N/C of more than 0.28. After relatively noncurative hepatic resection, the MST for cases with an N/C of less than 0.28 was 49 months, and this was significantly longer than the MST of 8 months for cases with an N/C of more than 0.28. The MST was 71 months for cases with a coefficient of variance of the nuclear form factor (NCV) of less than 5.5%, which was significantly longer than the MST of 33 months for cases with an NCV of more than 5.5% (P < 0.05). In stage III disease, the MST was 69 months for cases with an NCV of less than 5.5%, and this was significantly longer than the MST of 29 months for cases with an NCV of more than 5.5% (P < 0.05). In cases with an N/C of less than 0.28, 18% had vascular invasion and 38% had intrahepatic metastases, whereas in those with an N/C of more than 0.28, 62% had vascular invasion and 67% had intrahepatic metastases (P < 0.01, P < 0.05). Based on the results of these morphometric studies on HCC cases treated by hepatic resection, N/C and NCV may be useful as prognostic factors.

Carcinoma, Hepatocellular↗