High-resolution infrared spectroscopy of solid hydrogen.
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Journal Article↗
Biomedical subjects
T Oka
Publications and source records attributed to T Oka.
The enhanced cellular uptake of very-low-density lipoprotein enriched in apolipoprotein E.
We have recently reported an increased clearance of plasma very-low-density lipoprotein (VLDL) after intravenous injection of apolipoprotein (apo) E in Watanabe heritable hyperlipidemic (WHHL) rabbits. In the present study, we have investigated the cellular uptake of VLDL enriched in apo E (VLDL-E) which had been incubated with purified rabbit apo E. VLDL-E was taken up approx. 2-fold more than VLDL in human skin fibroblast, human monocyte-derived macrophage and Hep G2 cell and its degradation was least in macrophage. To characterize the binding of VLDL-E, we performed a binding assay using hepatic endosome isolated from estradiol-treated rats and we observed both increased EDTA-sensitive and -resistant binding of VLDL-E on endosome. Ligand blotting of hepatic endosome demonstrated two major bands of LDL receptor (130 and 260 kDa protein) and a minor band of LDL receptor-related protein (580 kDa protein) with a ligand of VLDL-E. These results suggested that VLDL-E was endocytosed in liver through a similar pathway among three cell types, and enrichment of apo E in VLDL enhanced the uptake of VLDL not only via an EDTA-sensitive binding site (classical LDL receptor) but also via other binding sites including an EDTA-resistant binding site and an LDL receptor-related protein.
Animals↗
Molecular analysis of a Bjerkandera adusta lignin peroxidase gene.
A cDNA clone, lambda LPO-1, encoding a major lignin peroxidase from the basidiomycete Bjerkandera adusta was isolated and characterized. The nucleotide sequence of lambda LPO-1 predicts a mature protein consisting of 349 amino acids with a molecular weight of 37,225 preceded by a signal peptide of 23 amino acid residues. We have also cloned and sequenced the gene encoding lignin peroxidase from B. adusta. Comparison of these sequences reveals a lignin peroxidase gene structure consisting of 1,116 bp of protein-encoding DNA that is interrupted by four intervening sequences. The putative eukaryotic regulatory sequence, a TATA box, is present at position -75 relative to the translational initiation codon. Amino acid sequence homology between the coding regions of lambda LPO-1 and of the lignin peroxidase cDNA clone lambda ML-1 from Phanerochaete chrysosporium is 61%.
Amino Acid Sequence↗
Characterization of two human lymphoid cell lines producing human T-lymphotropic virus type I (HTLV-I) isolated from patients with HTLV-I-associated myelopathy or encephalopathy.
Two cell lines, CNS-5 and CNS-6, were established by cocultivation of sedimented cells in cerebrospinal fluid (CSF) from two anti-human T-lymphotropic virus type I (HTLV-I) antibody-positive male patients with encephalopathy and HTLV-I-associated myelopathy, respectively, with peripheral blood mononuclear cells from a healthy seronegative female. These cell lines, possessing a normal female karyotype, revealed similar characteristics as follows; they expressed HTLV-I-related antigens, they produced C-type retrovirus particles, HTLV-I provirus genomes were integrated into their DNAs, and they had CD4+ activated T-cell markers. In addition, immunocytochemical and immunoelectron microscopic studies showed peculiar immunoreactivity of these cell lines with anti-alpha/beta T-cell antigen receptor (TCR) antibodies; beta Fl, defining beta chain epitope, was only positive in the perinuclear spaces and rough endoplasmic reticulum in some cells, and WT31, recognizing alpha/beta framework, was mostly negative, while CD3 was expressed in the majority of the cells. These facts indicate that HTLV-I-infected cells were present in CSF of these two patients, and suggest that neurological disorders associated with HTLV-I may not be restricted to myelopathy and may include brain abnormalities.
Aged↗
Oscillating activity of a calcium-activated K+ channel in normal and cancerous mammary cells in culture.
Calcium-activated potassium channels were the channels most frequently observed in primary cultured normal mammary cell and in the established mammary tumor cell, MMT060562. In both cells, single-channel and whole-cell clamp recordings sometimes showed slow oscillations of the Ca2(+)-gated K+ current. The characteristics of the Ca2(+)-activated K+ channels in normal and cancerous mammary cells were quite similar. The slope conductances changed from 8 to 70 pS depending on the mode of recording and the ionic composition in the patch electrode. The open probability of this channel increased between 0.1 to 1 microM of the intracellular Ca2+, but it was independent of the membrane potential. Charybdotoxin reduced the activity of the Ca2(+)-activated K+ channel and the oscillation of the membrane current, but apamin had no apparent effect. The application of tetraethylammonium (TEA) from outside and BaCl2 from inside of the cell diminished the activity of the channel. The properties of this channel were different from those of both the large conductance (BK or MAXI K) and small conductance (SK) type Ca2(+)-activated K+ channels.
Animals↗
Long-term results of living related kidney transplantation: a retrospective study on 114 recipients followed over 10 years.
The long-term patient and graft survivals, causes of death, complications and rehabilitation status in the second decade were analyzed in 114 patients who received living related kidney transplants and were followed up for 10 years or longer. Azathioprine and prednisolone were used for basal immunosuppressive therapy in all patients. The actual patient and graft survival rates at 10 years were 76.3 per cent and 50.9 per cent respectively, the main causes of death being serious infection (10 cases), malignant disease (5 cases), cerebral bleeding (4 cases), hepatic failure (3 cases), gastrointestinal bleeding (2 cases) and cardiovascular disorder (2 cases). Four patients died from complications after re-admission for hemodialysis. The cumulative patient and graft survival rates at 15 years in 58 patients whose graft survived for over 10 years were 87 per cent and 75 per cent, respectively. Of the 51 patients still surviving at the end of the study, the complete rehabilitation rate was 90.2 per cent, however, de novo malignant disease and hepatic disorder were significant complications which not only disturbed the patients' quality of life but also reduced their survival rate. Therefore, regular follow-up of patients and appropriate management procedures are necessary to enhance the long-term success of kidney transplantation.
Adult↗
Mechanical properties and immunogenicity of vascular xenografts.
Polyepoxy compounds (PC) have been introduced as new cross-linking agents to overcome some of the disadvantages of glutaraldehyde (GA). In this study, we investigated the relationship of the reaction time to the immunogenicity and mechanical properties of canine and bovine common carotid arteries cross-linked with one of PC, namely, glycerol polyglycidyl ether (GPE). To evaluate mechanical properties, we made use of the finite deformation theory. Arteries cross-linked with GPE for 48 hours proved to be about 3 times as flexible as those cross-linked with GA for 48 hours. In the immunogenicity experiments, GPE was observed to reduce the immunogenicity of the arteries according to the reaction time, and the arteries, which were cross-linked with GPE for 48 hours, showed little immunogenicity. It was concluded that GPE is a more suitable cross-linking agent than GA, and its optimum reaction time seems to be 48 hours.
Animals↗
Effects of oleic, arachidonic and 5,8,11,14-nonadecatetraenoic acids on lipid secretion and ketogenesis in perfused rat liver.
The effects of perfused oleic (18:1n-9), arachidonic (20:4n-6) and 5,8,11,14-nonadecatetraenoic (19:4n-5) acids on triglyceride and cholesterol secretion and ketone body production were studied in isolated rat liver. As compared to oleic and 19:4n-5 acids, both ketone body production and triglyceride secretion were significantly lowered when arachidonic acid was perfused. The concentration of triglyceride in the post-perfused liver was lower upon perfusion with arachidonic acid than upon perfusion with oleic acid or 19:4n-5 acid. Cholesterol secretion in the liver perfused with arachidonic acid or 19:4n-5 acid was significantly higher than with oleic acid. The concentration of cholesterol in the post-perfused liver was slightly but significantly higher with 19:4n-5 acid than with the other fatty acids. The results suggest that 19:4n-5 acid when compared with arachidonic acid affects lipid metabolism in liver differently.
Animals↗
Morphological characterization of a newly established human osteosarcoma cell line, HS-Os-1, revealing its distinct osteoblastic nature.
A newly established human osteosarcoma cell line, HS-Os-1, from an osteoblastic tumor arising in the left humerus of an 11-year-old girl was morphologically characterized in vitro and in vivo. HS-Os-1 cells in a monolayer have been maintained for more than 2 years since the initial cultivation, and were round or polygonal in shape with marked pleomorphism. Their cytoplasm was strongly positive for specific markers of osteoblasts, such as alkaline phosphatase and osteocalcin. Tumors induced in nude mice by HS-Os-1 cell inoculation at passage 12 or 23 revealed typical histological features of osteoblastic osteosarcoma, similar to those observed in the original tumor, producing prominent osteoid matrix with calcification. Ultrastructurally, HS-Os-1 cells in vitro and tumor cells in vivo showed similar well-developed, markedly dilated rough endoplasmic reticulum, polysomes and microfilaments in their cytoplasm. Additionally, many collagen fibers associated with deposition of electron-dense material were detected in the stroma featuring osteoid matrix. Thus, the HS-Os-1 cell line was shown to exhibit its osteoblastic nature in vitro and in vivo, and therefore might become an extremely useful tool for various pathomorphological investigations on human osteosarcomas.
Animals↗
Effects of portal vein occlusion on myocardial contractility.
We studied canine left ventricular contractile performance following 15 min of portal vein occlusion by analyzing the end-systolic pressure diameter relationship (ESPDR) which many investigators have reported as being independent of changes in preload and afterload but sensitive to changes in ventricular contractility. Portal vein occlusion for 15 min decreased the mean arterial pressure, left ventricular peak systolic pressure, and cardiac index, while the release of the occlusion gradually increased these values, although it did not restore them to the control values. The systemic vascular resistance index increased during portal vein occlusion and returned to the control values after release. Left ventricular end diastolic diameter decreased during portal clamping and returned to the control values after release. ESPDR and percent shortening were not significantly changed during or after portal clamping. These results indicate that the decrease in blood pressure during portal vein occlusion was not due to a reduction in myocardial contractility but rather was due to a reduction in preload.
Journal Article↗
Comprehensive treatment of bilateral cleft lip by multidisciplinary team approach.
Repair of bilateral cleft lip presents numerous problems, and in our opinion, it is better to begin treatment at the earliest age possible. At Fujita Health University Hospital, we utilise a multidisciplinary team approach to cleft lip. Nonsurgical correction of the nasal deformity using a nose retainer and preoperative orthodontics using a Kuwahara-modified Hotz's palatal plate begins soon after birth. Surgical repair of the lip is done within the first 2 months of life, by the time the nose, alveolus and projecting prolabium are adequately reformed. A one-stage surgical procedure, including restoration of muscle union, labial sulcus construction and nasal correction is performed. After lip repair, lip and tongue pressure are well balanced by the plate, and a good alignment of the alveolus can be achieved. A total of 27 cases of bilateral cleft lip were treated from August 1986 to October 1990. In all cases, the postoperative course was uneventful, and no complications due to early surgery were encountered.
Cleft Lip↗
Temperature- and ionic strength-induced conformational changes in the lipid head group region of liposomes as suggested by zeta potential data.
Neutral liposomes composed of DMPC (dimyristoylphosphatidylcholine), DPPC (dipalmitoylphosphatidylcholine) or DSPC (distearoylphosphatidylcholine) are found to exhibit non-zero zeta potentials in an electric field even when they are dispersed in solution at pH 7.4. A model for the orientation of lipid head groups is proposed to explain the observed non-zero zeta potentials. The dependence of the zeta potential on temperature and ionic strength is analyzed via this model to obtain the information on the direction of the lipid head group in the liposome surface region. The direction of the lipid head group is found to be sensitive to the temperature and the ionic strength of the medium. At low ionic strengths, the phosphatidyl groups are located at the outer portion of the head group region. At constant temperature, as the ionic strength increases, the choline group approaches the outer region of the bilayer surface while the phosphatidyl group hides behind the surface. At the phase transition temperature of the lipid, the phosphatidyl group lies in the outer-most region of the surface and the choline group is in the inner-most region.
1,2-Dipalmitoylphosphatidylcholine↗
An immunohistochemical study of bronchial cells producing surfactant protein A in the developing human fetal lung.
A study on immunohistochemical localization of pulmonary surfactant protein A (SP-A) in the developing human fetal lung was performed using a monoclonal antibody, PE10, against human SP-A. At 21 weeks of gestation, a few bronchial cells positive to PE10 were observed to be scattered in the main and segmental bronchi. The number of these cells appears to increase until the 32nd week of gestation, and then decrease thereafter, almost disappearing by 39 weeks. On the other hand, alveolar type II cells and Clara cells positive to PE10 began to appear at 29 weeks, increase in number until around 39 weeks, and remain constant throughout adulthood. A few bronchial glandular cells positive to PE10 were still noticed in the fetal lung. This is the first report of the presence of SP-A-containing cells in the fetal lung. This is the first report of the presence of SP-A-containing cells in the human fetal bronchial epithelium (not Clara cells in the terminal bronchiolus), proving the regularity of the sequential distribution of SP-A-containing cells in the bronchoalveolar system during pulmonary development.
Aged↗
Bestatin administration and the change in cellular immunity.
The change in cellular immunity by Bestatin (ubenimex) treatment--30 mg/day orally--was investigated in 23 gastrointestinal cancer patients for: 1), functional T cell subsets; 2), IL-2 receptor; 3), PHA-induced blastogenesis; and 4), PPD skin reaction. The absolute number of helper T cells (Th) and cytotoxic T cells (Tc) increased in 74 and 79% of cases, respectively, compared with pretreatment values. On the other hand, the absolute number of suppressor T cells (Ts) decreased in 79% of cases. IL-2 receptor increased in 56% of patients, PHA blastogenesis increased in 67% of patients and PPD skin reaction was elevated in 75% of cases comparing to pretreatment values. These results suggest that Bestatin could increase cellular immunity in cancer patients.
Antibiotics, Antineoplastic↗
Monoclonal-antibody-based enzyme-linked immunosorbent assay for HMG 2b nonhistone protein in chick liver.
Monoclonal antibodies were prepared against the high mobility group (HMG) protein 2b from chick liver chromatin and a monoclonal-antibody-based enzyme-linked immunosorbent assay (ELISA) was developed for chick HMG 2b. The sensitivity of the assay is about ten times that of the previously described radioimmunoassay and solid-phase enzyme immunoassay for HMG proteins. With the use of ELISA technique, the amount of HMG 2b (micrograms protein/mg DNA) in the livers of 1-day old and 70-day old chicks was found to be 2.56 +/- 0.4, and 1.20 +/- 0.2, respectively. The age-dependent change in the level of HMG proteins probably reflects changes in the functional state of chromatin during ageing.
Animals↗
Reconstitution of GTP-binding Sar1 protein function in ER to Golgi transport.
In the yeast secretory pathway, two genes SEC12 and SAR1, which encode a 70-kD integral membrane protein and a 21-kD GTP-binding protein, respectively, cooperate in protein transport from the ER to the Golgi apparatus. In vivo, the elevation of the SAR1 dosage suppresses temperature sensitivity of the sec12 mutant. In this paper, we show cell-free reconstitution of the ER-to-Golgi transport that depends on both of these gene products. First, the membranes from the sec12 mutant cells reproduce temperature sensitivity in the in vitro ER-to-Golgi transport reaction. Furthermore, the addition of the Sar1 protein completely suppresses this temperature-sensitive defect of the sec12 membranes. The analysis of Sar1p partially purified by E. coli expression suggests that GTP hydrolysis is essential for Sar1p to execute its function.
Cloning, Molecular↗
Plasma immunoreactive endothelin, but not thrombomodulin, is increased in patients with essential hypertension and ischemic heart disease.
To ascertain an involvement of vascular endothelial cells in cardiovascular disease, we have determined plasma levels of two endothelium-derived substances, endothelin (ET) and thrombomodulin (TM), in essential hypertension (EH) and ischemic heart disease. Plasma ET was determined by radioimmunoassay (RIA) after extraction. Plasma TM levels were determined by enzymunoimmunoassay. Plasma ET levels were significantly elevated in patients with EH involving target organ damage, vasospastic angina pectoris (VSA), and acute myocardial infarction (AMI), especially in those associated with cardiogenic shock. There was a weak but significant correlation between plasma ET levels and serum creatinine concentration in patients with EH. Plasma ET levels were elevated even before the coronary spasm in patients with VSA, whereas they did not show any further increase during the spasm. In contrast, plasma TM levels in patients with EH and VSA did not show a significant difference from that in normal subjects. These results suggest that ET plays an important role in the pathophysiology of EH and ischemic heart disease, and also that increases in plasma ET cannot be simply attributed to a leakage of the peptide from the injured endothelial cells.
Angina Pectoris↗
Sequential determinations of serum interleukin 6 levels as an immunodiagnostic tool to differentiate rejection from nephrotoxicity in renal allograft recipients.
Serum interleukin 6 (IL-6) levels were utilized as an immunologic marker of activation of T cells and macrophages in renal allograft recipients treated with a cyclosporine and prednisone immunosuppressive regimen. IL-6 concentrations were estimated in serum samples selected to correspond to similar timepoints in the clinical courses of renal transplant recipients suffering four types of events: group I, quiescent patients without rejection or infectious disease (n = 16, 147 samples); group II, patients with only rejection episodes (n = 26, 291 samples); group III, patients with only infectious episodes (n = 10, 87 samples); and group IV, patients with CsA-induced nephrotoxicity (n = 15, 117 samples). Serum IL-6 activity measured using an IL-6-dependent cell line (MH60.BSF-2) was specific for this lymphokine based upon the capacity of monoclonal anti-IL-6 antibodies to block target cell proliferation. The control group displayed uniformly elevated IL-6 levels during the first posttransplant day (mean 20.1 +/- 4.1 U/ml range 6.4-64 U/ml), thereafter decreasing by 10-14 days to a mean level of 3.4 +/- 0.9 U/ml (range 1.0-4.2 U/ml). The rejection group showed increased IL-6 levels ranging from 5.3 +/- 0.4 U/ml (range 1.0-64 U/ml) to 56.2 +/- 13.3 U/ml (range 10-300 U/ml, P less than 0.01), occurring at a mean of 2 days (range 0-10 days) before the diagnosis of rejection was established by clinical criteria. Interestingly, all three recipients treated with OKT3 and 5/11 treated with antilymphocyte globulin displayed further significant increases in serum IL-6 levels (OKT3: 46.0 +/- 12.9 U/ml; ALG: 34.6 +/- 7.8 U/ml) one day after inception of treatment. Five of 10 recipients displaying septic events showed elevated serum IL-6 activity--namely, 5.0 +/- 1.2 U/ml to 47.5 +/- 16.2 U/ml, beginning at a mean of 1.2 days before diagnosis. Contrariwise, recipients afflicted with CsA-induced nephrotoxicity displayed reduced IL-6 levels (mean = 1.4 +/- 0.18 U/ml). The ratio (IL-6 activity/CsA trough level) proved to be even more useful than the serum IL-6 level itself to discriminate acute rejection from nephrotoxicity--namely, 0.53 versus 0.006, respectively (P less than 0.01).
Antibodies, Monoclonal↗