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Biomedical subjects

J Takeuchi

Publications and source records attributed to J Takeuchi.

At least 163 records · Page 9Linked to original sources
PubMed1988

Localization of cytoplasmic and mitochondrial aldehyde dehydrogenase isozymes in human liver.

Aldehyde dehydrogenase isozymes (ALDH1 or E1 and ALDH2 or E2 according to the classification by Greenfield NJ, Pietruszko R, Biochim Biophys Acta 483:35, 1977) were purified from the human liver to homogeneity by the use of ion exchange chromatography on CM-Sephadex, DEAE-Sephadex, and QAE-Sephadex and affinity chromatography on 5'-AMP Sepharose 4B, and preparative isoelectric focusing agarose electrophoresis. These were injected in rabbits to elicit antibodies against ALDH1 and ALDH2, respectively and their specificities were tested by double immunodiffusion. By gel filtration, the antibodies were separated into F'ab fragments, conjugated with horseradish peroxidase, and served to detect ALDH1 and ALDH2 proteins in normal liver tissue. Immunoelectron microscopy by the preembedding method revealed that the electron-dense materials reacted with anti-ALDH1 antibody were located in the cytoplasm of hepatocytes, mainly around the nuclear membrane, mitochondria, and endoplasmic reticulum; in the mitochondria, however, no staining was demonstrated. In contrast, the reaction with anti-ALDH2 antibody was observed only in the mitochondria. Immunostaining, performed by the enzyme-labeled antibody method demonstrated that in the hepatic lobule, there were no differences of the intensity of ALDH1 antigenicity and that of ALDH2 antigenicity between periportal (zone 1) and pericentral (zone 3) hepatocytes. These results suggest that in the human liver ALDH1 and ALDH2 are distributed equally in the periportal and centrilobular regions.

Aldehyde Dehydrogenase↗
PubMed1988

Functional heterogeneity of rat hepatocytes: predominance of aryl hydrocarbon hydroxylase activity in perivenular zone.

To elucidate the hepatic intralobular distribution of aryl hydrocarbon hydroxylase (AHH) activity biochemically, periportal (PP) and perivenular hepatocytes (PV) from male Sprague-Dawley rats were separated by a fluorescence-activated cell sorter after labeling the PP zone with fluorescein diacetate and the perivenular zone with fluorescein isothiocyanate. AHH activity was higher in PV than in PP. The enzyme activity was induced about 6-fold in hepatocytes of rats pretreated with 3-methyl-cholanthrene, and the induction was more prominent in PP than in PV. Neither phenobarbital pretreatment nor altered lipid content of the diet induced the change in the enzyme activity.

Animals↗
PubMed1987

Isolation and characterization of proteoglycans from human nonepithelial tumors.

Proteoglycans (PGs) and glycosaminoglycans (GAGs) were identified in myogenic and fibrogenic tumors. More PGs containing mainly chondroitin sulfate could be detected in malignant tumors (leiomyosarcomas) than in benign tumors (leiomyomas and fibromas). Two groups of PGs were detected in the malignant tumors by ion-exchange chromatography and gel chromatography. One group was a large molecule with chondroitin sulfate side chains, seemingly composed of two or more subpopulations that were eluted from Sepharose CL-4B with a kav of 0.45. After removal of GAG side chains from the PG by chondroitinase AC digestion, core molecules with molecular weights greater than 200,000 were obtained. Another PG detected was a fraction of small PG eluted from Sepharose CL-4B with a kav of 0.45. It consisted of a core molecule with a molecular weight approximately equal to 48,000 and GAG side chains containing chondroitin sulfate-dermatan sulfate hybrids. The mixed sequence of L-iduronic acid with D-glucuronic acid in the same GAG chain was demonstrated by the formation of a small proportion of tetrasaccharide after chondroitinase AC digestion. In the benign tumors, the large PG was found only in very small amounts, and PG detected was composed mainly of the small one eluted from Sepharose CL-4B with a kav of 0.45. Its core protein had a molecular weight of approximately equal to 46,000, which was similar to that of small PG obtained from leiomyosarcomas, but its GAG side chains were composed mainly of dermatan sulfate containing small amounts of glucuronic acid. The results suggest that the core molecules of small PGs from both benign and malignant tumors are the products of the same gene but that they are processed in a different manner to form proteoglycans with different types of GAG chains.

Electrophoresis, Polyacrylamide Gel↗
PubMed1987

Isolation of Inoue-Melnick virus from human meningioma-derived cell cultures and detection of antibody in patients with meningioma.

Inoue-Melnick virus (IMV) was isolated from six of seven human meningioma-derived cell cultures, while the virus was not isolated from six other brain tumor cell cultures. Sera of 145 consecutive neurosurgical inpatients were tested for IMV-neutralizing antibody. Of 26 patients with meningioma, 22 were positive for IMV antibody (84.6%). Of the remaining 119 patients, 16 were positive.

Antibodies, Viral↗
PubMed1987

Cytogenetic studies in hairy cell leukemia.

Cytogenetic analyses were performed on cells from 17 patients with hairy cell leukemia stimulated with polyclonal B-cell activators (in 155 different cultures). No mitosis was obtained in samples from four cases (23.5%). Of 14 bone marrows, four (28.6%) showed mitoses, two with clonal abnormalities. All four samples from the spleen had mitoses with four clonal changes; eight of 13 (37.5%) blood samples had mitoses with three clonal changes. Of the polyclonal B-cell activators (PBA), lipopolysaccharide and protein A seemed to be effective for the detection of clonal abnormalities in hairy cell leukemia. Among the clonal aberrations, chromosomes #3, #10, and #17 were affected in two cases each; frequent numerical changes were monosomies of #10 and #17 and structural changes were deletions at band 3p21 (two cases), 6q-, and der(9)t(9;?)(p22;?). The chromosomal bands involved in structural changes were close to accepted constitutive fragile sites.

B-Lymphocytes↗
PubMed1987

Generation of pH gradient across the rabbit collecting duct segments perfused in vitro.

Ability of pH gradient generation was examined in three segments of rabbit collecting duct, cortical collecting duct (CCD), outer medullary collecting duct (OMCD) and inner medullary collecting duct (IMCD). These segments were perfused in vitro, and the steady-state luminal pH in stop-flow condition (pHs) and the electrochemical potential difference of H+ (EH) were determined using double-barreled liquid membrane pH microelectrode punctured into the lumen. In CCD, pHs was 7.71 +/- 0.08 in normal rabbits, 7.72 +/- 0.08 in DOCA-treated rabbits and 7.27 +/- 0.05 in starved rabbits, while peritubular fluid was kept at pH 7.5 EH (positive value means H+ accumulation in the lumen above electrochemical equilibrium) was -15.3 +/- 5.2, -31.3 +/- 3.7 and 10.3 +/- 3.1 mV, respectively. Peritubular acidification (peritubular pH 6.8) by reducing HCO3-concentration decreased pHs, but increased its negativity of EH in all groups. In OMCD pHs was 6.57 +/- 0.08 in normal, 6.58 +/- 0.11 in DOCA-treated and 6.47 +/- 0.12 in starved animals. EH was 54.5 +/- 4.6, 57.7 +/- 6.8 and 64.2 +/- 6.9 mV, respectively. Peritubular acidification lowered pHs further, 5.51 +/- 0.07, 5.67 +/- 0.16 and 5.41 +/- 0.19, respectively. EH was enhanced in all groups. In IMCD pHs was 7.36 +/- 0.04 with EH being 6.8 +/- 2.9 mV, and peritubular acidification did not generate pH gradient. These data suggest that the generation of a steep acid pH gradient is mainly due to OMCD. Luminal alkalinization predominated in CCD except in starved rabbits. IMCD did not generate appreciable pH gradient.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis↗
PubMed1987

The frequency and histology of hepatic tissue in germ cell tumors.

The frequency of hepatic tissue and its histological characteristics were examined in 516 germ cell tumors. Hepatic tissue was observed in 48 cases (9.3%). The incidence of hepatic tissue was low in tumors of the ovary (5%), high in both retroperitoneal (27%) and sacro-coccygeal (24%) tumors, and low in both mature (0.3%) and immature teratomas (11%). It was usually encountered in infancy, and the frequency was high in both yolk sac tumors (48%) and mixed germ cell tumors (52%). The hepatic tissue found mainly in mature or immature grade 1 teratomas was similar to adult normal human liver tissue (Ha-type). Tissue in areas consisting of some immature somatic elements of a mixed germ cell tumor was similar to embryonic or fetal liver tissue (Hf-type). Many hepatic nests found in a polyembryoma were of both Ha- and Hf-types. The hepatic tissue found in close relation to yolk sac elements showed predominantly hepatocellular carcinoma-like features (HCLS). Immunohistochemically, the cytoplasm of adult liver-type cells was positive for alpha-1-antitrypsin (AAT), human albumin (ALB), and the third (C3) and fourth (C4) components of the complement system. The cytoplasm of fetal liver-type cells showed the same positivity; in addition, these cells were positive for alpha-fetoprotein (AFP) in 25% of the cases. The cytoplasm of hepatic cells of HCLS was positive for AFP, AAT, ALB, C3, and C4. A weakly positive reaction for CEA and CA19-9 was observed in bile duct-like structure in some Hf-type cases.

Adult↗
PubMed1987

Mechanism of bicarbonate exit across basolateral membrane of rabbit proximal straight tubule.

To clarify the mechanism(s) of HCO3- (or related base) transport across the basolateral membrane, rabbit proximal straight tubules were perfused in vitro, and intracellular pH (pHi) and Na+ activity (aiNa) were measured by double-barreled ion-selective microelectrodes. Lowering bath HCO3- from 25 to 5 mM at constant PCO2 depolarized basolateral membrane potential (Vbl), and reduced pHi. Most of these changes were inhibited by adding 1 mM 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS) to the bath. Total replacement of bath Na+ with choline also depolarized Vbl and reduced pHi, and these changes were also inhibited by SITS. Reduction in aiNa was observed when bath HCO3- was lowered. Taken together, these findings suggest that HCO3- exists the basolateral membrane with Na+ and negative charge. Calculation of the electrochemical driving forces suggests that the stoichiometry of HCO3-/Na+ must be larger than two for maintaining HCO3- efflux. Total replacement of bath Cl- with isethionate depolarized Vbl gradually and increased pHi slightly, implying the existence of a Cl(-)-related HCO3- exit mechanism. The rate of decrease in pHi induced by lowering bath HCO3- was slightly reduced (20%) by the absence of bath Cl-. Therefore, the importance of Cl(-)-related HCO3- transport is small relative to total basolateral HCO3- exit. Accordingly, these data suggest that most of HCO3- exits the basolateral membrane through the rheogenic Na+/HCO3- cotransport mechanism with a stoichiometry of HCO3-/Na+ of more than two.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1987

Factors that affect oxygen affinity of hemoglobin in chronic hemodialysis patients.

To investigate various factors that possibly affect oxygen affinity of hemoglobin (Hb-O2 affinity) in chronic hemodialysis (HD) patients, we determined P50 at standard condition (P50std), 2,3-diphosphoglycerate (2,3-DPG) content in red blood cells, serum inorganic phosphorus (S-Pi), Hb, and arterial blood gas analysis in 55 HD patients. P50std in HD patients was higher than that in normal controls (26.6 +/- 1.6 vs. 25.4 +/- 1.4 mm Hg; p less than 0.001). We could find neither an effect of alkalizating agents for HD (acetate vs. bicarbonate) nor an effect of the underlying disease (diabetics vs. nondiabetics) on Hb-O2 affinity. There were significant positive correlations between P50std and the duration of HD therapy (r = 0.598; p less than 0.001) and between P50std and SPi (r = 0.476; p less than 0.001), contrasting with the absence of correlation between P50std and Hb. Forward stepwise multiple-regression analysis demonstrated that the duration of HD therapy played the most important roles in determining P50std, followed by SPi and PO2. These data suggest that the major factor influencing Hb-Os affinity in chronic HD therapy is the duration of the therapy and that the minor factors are SPi and PO2.

2,3-Diphosphoglycerate↗
PubMed1987

A triplet pregnancy after gonadotropin-releasing hormone pulsatile infusion therapy in a postoperative case of growth hormone-producing pituitary macroadenoma.

Intravenous GnRH pulsatile infusion therapy (10 micrograms/pulse, 90-min interval) was conducted in an acromegalic patient from whom 2/3 of a GH-producing pituitary macroadenoma had been removed. Before infusion therapy, plasma levels of GH and PRL were 10-20 and 15-25 ng/ml, respectively, while those of LH and FSH were subnormal without intrinsic fluctuations. Ovulation was induced after 13 days of infusion which was terminated on the 23rd day of therapy. Luteal function was supported by hCG (5,000 IU per dose) which was given 4 times from the 23rd to the 31st day of the treatment cycle. Triplet pregnancy was diagnosed ultrasonographically within 7 weeks of gestation. Although GH and PRL levels increased gradually as the gestational period progressed and plasma levels of GH and PRL of 32-55 and 30-67 ng/ml, respectively, were detected after 30 weeks of gestation, neither adverse signs related to the enlargement of the residual pituitary tumor nor manifestation of acromegaly was observed. The immunoreactive somatomedin-C levels during this period were not greater than those in normal pregnant women. Caesarean section was performed at 34 weeks and 3 normal healthy infants were delivered. Detailed analyses of hormonal changes throughout the period of GnRH pulsatile infusion and subsequent luteal phase revealed that the triplet pregnancy had been induced by the GnRH therapy itself and that hCG stimulation did not play any critical role. The residual tumor mass secreted increasing amounts of GH during the latter period of pregnancy but the somatomedin-C levels were not associated with this elevation. Therefore, the clinical as well as the hormonal findings strongly suggested that the GH secreted in increasingly large amounts by the residual tumor mass during pregnancy was defective in certain biological properties.

Adenoma↗
PubMed1987

Comparison of susceptibility of myopotential inhibition between AAI and VVI pacemakers.

Susceptibility of unipolar AAI pacemakers to myopotential inhibition (MPI) was assessed in 10 patients by provocative maneuvers and 24-hour Holter monitoring, and compared to that of unipolar VVI pacemakers in 12 patients. Five maneuvers were performed for each of four different sensitivity levels, and an MPI score of from 0-4 points was given according to the lowest sensitivity level at which MPI was provoked. The MPI score in patients with AAI pacemakers was significantly lower than that in patients with VVI pacemakers, 1.60 +/- 1.26 vs 2.83 +/- 1.03 (p less than 0.05). On Holter monitoring, no MPI was detected in any of the patients with AAI pacemakers, whereas myopotential inhibition was detected in 5/12 patients (42%) with VVI pacemakers. Intracardiac electrograms were of lower amplitudes for AAI pacing than for VVI pacing, 3.13 +/- 1.83 mV vs 11.20 +/- 5.95 mV (p less than 0.01). Although the amplitude of atrial signals was lower than that of ventricular signals, the AAI pacemakers were less susceptible to MPI than were the VVI pacemakers. However, when MPI occurs in AAI pacing, it may be more difficult to correct without undersensing because of the lower amplitude of the intracardiac signals.

Adult↗