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Biomedical subjects

Y Hirota

Publications and source records attributed to Y Hirota.

At least 181 records · Page 10Linked to original sources
PubMed1994

Stage-synchronization of the seminiferous tubules after vitamin A replacement in vitamin A deficient golden hamsters.

The effect of vitamin A deficiency and vitamin A replacement on spermatogenesis in golden hamsters was studied using a light microscope. Male golden hamsters were fed a vitamin A deficient (VAD) diet from 3 weeks of age. Hamsters with a VAD diet reached maximum body weight at about 13 weeks. After 17 weeks, the body weight of the hamsters began to decrease. When their body weight decreased to 70 g, only Sertoli cells, spermatogonia, and a few spermatocytes were present within the seminiferous tubules. Administering retinol acetate (vitamin A) combined with a conventional diet to the VAD hamsters induced a reinitiation of spermatogenesis with stage-synchronization. At 9, 10, and 11 weeks after vitamin A replacement, the testes with active spermatogenesis possessed only a few successive stages of the seminiferous epithelial cycle.

Animals↗
PubMed1994

Identification and carbohydrate specificity of a chicken serum mannan-binding protein reactive with a Ra chemotype strain of Salmonella typhimurium.

To compare a chicken serum mannan-binding protein (MBP) with a chicken Ra-reactive factor (RaRF), both serum proteins were isolated by combination of different chromatography. In SDS-PAGE, both purified proteins were resolved into a major protein band with a molecular weight of 34,000 and a few minor protein bands. In Western blotting with both purified proteins, only a single band with a molecular weight of 34,000 was detected with anti-chicken serum MBP antibody, indicating that the major protein band of chicken serum MBP and RaRF are antigenically identical. The combining sites of these two proteins were most reactive with N-acetylmannosamine followed by mannose, N-acetylglucosamine, and L-fucose. These findings suggest that chicken serum MBP may be identical to its corresponding bactericidal factor RaFR in terms of antigenicity and monosaccharide specificity.

Acute-Phase Proteins↗
PubMed1994

Serum concentration of a bovine mannan-binding protein reactive with a Ra chemotype strain of Salmonella typhimurium: no significant changes associated with mastitis.

The serum concentration of a bovine mannan-binding protein reactive with a Ra chemotype strain of Salmonella Typhimurium in sera from cows with or without mastitis were determined by sandwich enzyme-linked immunosorbent assay. From the results obtained for 10 healthy cows aged 2 to 7 years, mean +/- SD serum concentrations of MBP in bovine sera were 77.5 +/- 33.1 micrograms/ml. Concentrations in 7 healthy heifer calves aged 6 months were 52.2 +/- 10.2 micrograms/ml, whereas those in 7 healthy bullocks 65.8 +/- 21.8 micrograms/ml. Concentrations in 4 cows aged 4 to 7 years with mastitis were slightly lower (34 to 72 micrograms/ml). After recovery, the serum concentrations rose to the normal concentrations in healthy cows. These findings indicate that the serum concentrations of bovine MBP decrease during mastitis, suggesting that bovine MBP may not be an acute phase reactant.

Acute-Phase Proteins↗
PubMed1994

Radio-opacity of the paranasal sinuses. Conventional views and CT.

In order to examine the reliability of conventional views in predicting the degree of radio-opacity, irrespective of soft tissue or fluid seen in chronic sinusitis in adults, a comparison has been made between the results of evaluations by two routine views (Caldwell's and Waters') and by CT in axial scans. Ninety-seven sides (61 case) were included in the study. The radio-opacity was classified into three groups according to the degree of aeration or radiolucency. The diagnosis of plain films were classified into three categories (matched diagnosis, over-diagnosis, and under-diagnosis) in comparison to the radio-opacity depicted by corresponding CT scans. The incidences of matched diagnosis are, in the order of percentages: maxillary sinus (78.4%), frontal sinus (71.1%), nasofrontal area (66.0%), anterior ethmoidal cells (52.6%), and posterior ethmoidal cells (52.6%). The incidence of over-diagnosis is highest in the posterior ethmoidal cells (52.6%) and lowest in the maxillary sinus (20.6%). The incidence of under-diagnosis is highest in the anterior ethmoidal cells (24.7%) and lowest in the maxillary sinus (1.0%).

Adolescent↗
PubMed1994

Orbital wall fractures. Conventional views and CT.

In order to evaluate the benefit derived by conventional views in the initial diagnosis of fractures of the orbital walls, a clinical study was designed to compare the results of evaluations by plain films and coronal CT scans. The conventional Caldwell's and Waters' views will provide a fairly reliable result as to the presence of orbital fractures: orbital floor (anterior in 78%, posterior in 73%), medial orbital wall (anterior in 71%, posterior in 72%), and ethmoid-maxillary plate in 64%. False-negative diagnosis was seen at the anterior portion of the floor in 13%, at the anterior portion of the medial orbital wall in 7%, and at the ethmoid-maxillary plate in 11%. False-negative diagnosis was seen at the orbital floor (anterior in 9%, posterior in 10%), at the medial orbital wall (anterior in 21%, posterior in 29%), and at the ethmoid-maxillary plate in 21%. Our results agree well with those of the past reports.

Adult↗
PubMed1993

Isolation of the chicken NF-kappa B p65 subunit-encoding cDNA and characterization of its products.

NF-kappa B is a heterodimeric transcription factor consisting of subunits of 50 kDa (p50) and 65 kDa (p65). cDNA clones encoding the chicken NF-kappa B p65 subunit were isolated. Sequence analysis showed that chicken p65 is approximately 55% identical to the mouse and human p65 proteins, and contains the Rel homology domain (RHD) in its N-terminal 286 amino acids (aa) and the putative transactivation domain in its C-terminal region. The RHD is particularly highly conserved between the chicken and mammalian p65 proteins. Northern blot hybridization analysis detected the expression of a 2.6-kb transcript of p65 in various organs, with the highest level in spleen. A fusion protein containing the RHD of chicken p65 was found to bind to a consensus kappa B-site in an electrophoretic mobility shift assay (EMSA). This binding was specifically inhibited by the presence of fusion proteins containing the C-terminal ankyrin repeats domain (ARD) of chicken p105, the precursor protein for the p50 subunit. Immunoprecipitation analysis showed that p65 formed a complex(es) with multiple cellular proteins, including p50, p105 and c-Rel in chicken spleen cells.

Amino Acid Sequence↗
PubMed1993

Human heart-type cytoplasmic fatty acid-binding protein in serum and urine during hyperacute myocardial infarction.

We have previously reported that serum and/or urinary human heart-type cytoplasmic fatty acid-binding protein (HH-FABPc) can be used as an early indicator of myocardial injury (Clin Biochem 1991; 24: 195-201). To confirm the usefulness of HH-FABPc as an early diagnostic indicator of acute myocardial infarction (AMI), its serum and urinary levels were measured in samples obtained within 6 h after the onset of acute coronary syndrome related symptoms. Samples were collected from 97 patients, who were composed of 63 with AMI, 24 with unstable angina and 10 with chest pain syndrome. The positivity of serum and urinary HH-FABPc and cardiac creatine kinase isozyme MB (CK-MB) was analyzed in these samples. Serum HH-FABPc levels in AMI were above normal in 91.4% (64/70) of the samples tested within 3 h of the onset of symptoms and in 100% (111/111) of those tested at 3-6 h. Elevated urinary HH-FABPc levels in AMI were obtained in 88.9% (8/9) of samples at 0-3 h and in 75% (6/8) at 3-6 h. CK-MB activity in AMI was positive in 20% (8/40) and 66.3% (53/80) of serum samples at 0-3 h and 3-6 h, respectively. HH-FABPc was always positive when a serum sample was positive for CK-MB. Serum HH-FABPc at 0-6 h in chest pain syndrome and in unstable angina were positive in 17.8% (5/28) and 56.7% (34/60), respectively. The elevated HH-FABPc in serum and urine was noted much earlier than that of CK-MB during the hyperacute phase of AMI. HH-FABPc showed high positive value in unstable angina, but it was low in normal coronary patients having chest pain. However, HH-FABPc level in unstable angina and chest pain syndrome was lower than that of AMI. Thus, HH-FABPc may be a valuable indicator for the diagnosis of hyperacute myocardial infarction.

Adult↗
PubMed1993

Cloning of a canine gene homologous to the human interleukin-8-encoding gene.

We cloned a 2.3-kb sequence homologous to the gene (hIL8) encoding human interleukin-8 (hIL-8) from the canine genome. The sequence may encode an 11.3-kDa protein consisting of 101 amino acids, sharing 75, 80 or 85% identity with the human, rabbit or porcine IL-8 proteins, respectively. Southern and Northern blot analyses indicated that the cloned sequence appeared to exist as a single copy in the canine genome, and that its expression was inducible with lipopolysaccharide in canine mononuclear cells, respectively. Thus, it seems very likely that the cloned gene is a canine homologue of hIL8.

Amino Acid Sequence↗
PubMed1993

Association of alcohol intake, cigarette smoking, and occupational status with the risk of idiopathic osteonecrosis of the femoral head.

To investigate the association of alcohol intake, cigarette smoking, occupation, and other factors with the development of idiopathic osteonecrosis of the femoral head, a nationwide multicenter case-control study was conducted in Japan during 1988-1990, comparing 118 cases with no history of systemic corticosteroid use with 236 controls matched for sex, age, ethnicity, clinic, and date of initial examination. The risks of developing femoral head necrosis associated with potential risk factors were estimated by adjusted relative odds obtained by a conditional logistic regression model. The elevated relative odds were observed for occasional drinkers (relative odds = 3.2, 95% confidence interval 1.1-9.2) and regular drinkers (relative odds = 13.1, 95% confidence interval 4.1-42.5) with a significant dose-response relation (p < 0.001). For current drinkers, the relative odds were 2.8, 9.4, and 14.8 for < 320, 320-799, and > or = 800 g/week of ethanol intake, respectively. An increased risk was found for current smokers (relative odds = 4.7, 95% confidence interval 1.5-14.5), but a linear increasing trend in the cumulative effect of smoking was not evident at 20 pack-years or over. A weak but significant dose-response relation was observed for daily occupational energy consumption (p < 0.05). The present study confirmed the strong association of alcohol intake and positive association of cigarette smoking and suggested the role of heavy physical work.

Adult↗
PubMed1993

Effect of sub-skinning concentrations of saponin on intracellular Ca2+ and plasma membrane fluidity in cultured cardiac cells.

To determine the underlying mechanisms of the positive inotropic effect of sub-skinning concentrations of saponin, we studied changes in the intracellular Ca2+ ([Ca2+]i) and plasma membrane fluidity after exposure to digitonin (a representative saponin) in cultured cardiac cells. [Ca2+]i was measured by use of the fluorescent calcium indicator Calcium Green-1. The membrane fluidity was evaluated by measuring the diffusion coefficient using the method of fluorescence recovery after photobleaching. 1,1'-Dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine perchlorate was used as the fluorescent probe. Digitonin at a sub-skinning concentration (0.1 to 1 microM) produced an increase in cell motion and an augmentation of [Ca2+]i. Membrane fluidity which is evaluated by the diffusion coefficient (from 0.34.10(-8) to 0.28.10(-8) cm2/s; P < 0.05), decreased in the presence of 0.2 microM digitonin while the cell maintained an augmented motion and an increased [Ca2+]i. The skinning concentration of digitonin (5 microM) produced a rapid contracture with a marked increase in [Ca2+]i. The membrane fluidity was further reduced (diffusion coefficient: 0.24.10(-8) cm2/s; P < 0.001). These results suggest that saponin at the sub-skinning concentration also causes holes in the plasma membrane by interaction with cholesterol, as was shown with the skinning concentration, and it increases [Ca2+]i, which thereby induces a positive inotropic effect.

Animals↗
PubMed1993

Signal joint of immunoglobulin V lambda 1-J lambda and novel joints of chimeric V pseudogenes on extrachromosomal circular DNA from chicken bursa.

We isolated extrachromosomal circular DNA from the bursa of 18-day chick embryos and cloned their BamHI fragments into a phage vector. We found examples of the signal joint fused by V lambda 1-J lambda rearrangement and the sequences homologous to V lambda 1 segments that showed: (1) clustered V pseudogene (psi V) germ-line segments containing new psi V26, (2) a head-to-tail duplication of psi V13-psi V12 region and (3) chimeric structures composed of 5'-V lambda 1 and 3'-psi V segments. Both intrachromosomal tandem duplications and extrachromosomal circles may be generated by unscheduled DNA synthesis and recombination. The chimeric structure of V lambda 1 joined with upstream psi V segments suggests the involvement of V gene replacement for somatic diversification of the immunoglobulin genes in addition to a mechanism of segmental gene conversion.

Animals↗
PubMed1993

Plasma and urinary heart-type cytoplasmic fatty acid-binding protein in coronary occlusion and reperfusion induced myocardial injury model.

The leakage of heart-type cytoplasmic fatty acid-binding protein (H-FABPc) from injured myocardial cells has been reported. We have previously proposed that its plasma and urinary levels could be used as an early indicator of myocardial injury and also reflect the severity of myocardial injury. To confirm this hypothesis, the time course of changes of the plasma and urinary H-FABPc was investigated during myocardial injury induced by coronary artery occlusion and reperfusion in dogs. The plasma elimination kinetics and urinary excretion kinetics of H-FABPc were also analysed in dogs which were given a bolus injection of exogenous H-FABPc. The distribution of circulating H-FABPc was determined in mice by whole-body autoradiography using 125I-labelled H-FABPc. In myocardial injury model, plasma and urinary H-FABPc level showed rapid increase after reperfusion. The elimination kinetic study revealed that H-FABPc was mono-exponentially cleared from the circulation. The elimination rate constant (Ke) was 0.0275 +/- 0.0094/min (mean +/- S.D., n = 7) and the disappearance half-time (t1/2) was 27.5 +/- 8.4 min (mean +/- S.D., n = 7). Exogenous H-FABPc appeared in urine soon after administration, with the peak level being at 6.9 +/- 2.0 min (mean +/- S.D., n = 7). Whole-body autoradiography also demonstrated that 125I-H-FABPc accumulated rapidly in the kidneys. This study demonstrated that H-FABPc leaked rapidly from injured myocardium and rapidly appeared in plasma and urine. Infarct size was closely correlated with the calculated H-FABPc release (r = 0.89, r2 = 0.80, P < 0.01, n = 7) and with the amount of the urinary H-FABPc (r = 0.94, r2 = 0.88, P < 0.01, n = 7). These data suggest that measurement of the H-FABPc levels in plasma and urine might be useful for the early detection of myocardial injury and also for the assessment of infarct size.

Animals↗
PubMed1993

Association between blood polychlorinated biphenyl concentration and serum triglyceride level in chronic "Yusho" (polychlorinated biphenyl poisoning) patients.

The association between blood polychlorinated biphenyl (PCB) concentration and serum triglyceride level was investigated in 259 "Yusho" patients (PCB poisoning) who underwent health examinations for Yusho in 1988. Geometric means of PCB and triglyceride were 3.84 ppb (95% confidence interval: 3.54-4.17) and 114.3 mg/dl (106.6-122.6), respectively. Both correlation and multiple regression analyses showed a weak but statistically significant correlation between these two variables. The mean triglyceride level adjusted for age and sex was then calculated for comparison among four PCB levels, using analysis of covariance. This indicated a progressive increase with increasing PCB: 98.36, 117.78, 117.84, and 127.65 mg/dl at < 2.7, 2.7+, 4.1+, and 6.1+ ppb, respectively (F = 2.01, P = 0.113). Comparing PCB levels, the difference in adjusted mean triglyceride levels was marginally significant between the first and second (P = 0.088), and the first and third quartiles (P = 0.066), and reached significance between the first and fourth quartiles (P = 0.021). Thus, a weak but significant association between blood PCB and serum triglyceride was observed in the patients 20 years after exposure, although their blood PCB and serum triglyceride were relatively close to the normal levels.

Adult↗
PubMed1993

Analysis of chicken CD4 by monoclonal antibodies indicates evolutionary conservation between avian and mammalian species.

We have created a panel of mouse monoclonal antibodies detecting different epitopes on avian CD4 molecule. Two-color immunofluorescence analysis shows that chicken peripheral alpha beta T cells are either CD4 or CD8 single positive whereas most gamma delta T cells are CD4-negative both in the thymus and peripheral tissues. Unlabeled antibody competition analysis by flow cytometry demonstrates that several different epitopes on chicken CD4 are recognized by these antibodies. Antibodies precipitate a monomeric glycoprotein from surface-labeled chicken thymocytes and T cells with relative molecular mass (M(r) of 64 kd as analyzed by SDS gel electrophoresis. Removal of N-linked carbohydrates by endoglycosidase-F increases the electrophoretic mobility and reveals the core protein size with M(r) of 45 kd. The anti-CD4 antibodies inhibit antigen-induced cellular proliferation of a keyhole limpet hemocyanin (KLH) -specific T cell line. They synergize in the blocking of T cell proliferation with anti-class II major histocompatibility complex (MHC)-specific antibodies indicating that chicken CD4 is involved in antigen recognition process by CD4+ T cells. We also show that chicken CD4 is down-modulated in a similar manner as its mammalian equivalent when thymocytes are stimulated in vitro with phorbol esters. Altogether these findings suggest functional and biochemical conservation of the CD4 molecule in evolution.

Animals↗
PubMed1993

Clonogenic hematopoietic progenitors and endogenous cytokine production in allogeneic bone marrow transplantation.

The suboptimal return of hematopoietic precursors after bone marrow transplantation is suggestive of a limited bone marrow reserve in recipients of allografts. The problem does not appear to lie in the ability to produce some of the well-known hematopoietic growth factors such as G-CSF or activities considered to stimulate megakaryocytopoiesis. The persistence of factor production in patients with slow returning counts is suggestive of either a defect in the repopulating cells or in the function of the microenvironment that is not reflected in the production of factors that can be measured in the plasma. A defect in the graft may be overcome by altering the composition of engrafting cells. As seen in autologous transplants the addition of peripheral blood stem cells may be effective in reducing the period to engraftment. Putative defects in the microenvironment have to be addressed by further studies. Exogenously added stroma related factors such as kit ligand or IL-11 may be effective in correcting the deficiency.

Bone Marrow Transplantation↗
PubMed1993

Inhibitory activity of camptothecin derivatives against acetylcholinesterase in dogs and their binding activity to acetylcholine receptors in rats.

A camptothecin derivative, 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11), shows a potent antitumour activity in experimental tumour models and in clinical trials. However, CPT-11 induced early diarrhoea and vomiting at high dose levels in clinical studies and showed an acetylcholine-like action on the guinea-pig ileum and trachea. In the present study, we investigated the activities of camptothecin derivatives in inhibiting acetylcholinesterase (AChE) and in binding to muscarinic acetylcholine receptors (AChR). CPT-11 inhibited AChE and binding of the specific ligand to AChR with respective 50% inhibition concentrations of 0.2 and 5 microM. These inhibitions were induced by camptothecin derivatives having an amino group at the C-10 position (or the C-4 position of hexacyclic derivatives), but were not or were only slightly induced by the others. Early defecation and vomiting in dogs were observed after intravenous injection of DU-6596 and DU-6888, two hexacyclic derivatives having the aminomethyl group at the C-4 position, and of CPT-11. DU-6174, however, which has a hydroxy group at this position, induced no early defecation and little vomiting. Plasma concentrations of CPT-11, DU-6596 and DU-6888 after intravenous treatment at doses causing such early adverse effects were maintained for 1 h or longer at levels sufficient to inhibit AChE. These results suggest that the inhibition of AChE by camptothecin derivatives with an amino group at the C-10 position (or the C-4 position) relates to the early defecation or diarrhoea and vomiting.

Animals↗