PubMed Health⌕ Search

Biomedical subjects

T Kitao

Publications and source records attributed to T Kitao.

At least 19 recordsLinked to original sources
PubMed2004

Sludge thickening performance of mesh filtration process.

Small-scale wastewater treatment facilities play an important role in improving the aquatic environment in many countries. Although sludge treatment is essential for overall wastewater treatment, it is difficult for small-scale facilities to use mechanical equipment or other facilities. As the first step of the sludge treatment, it is important to develop a convenient sludge thickening process for small-scale facilities. In this work, we examined the sludge thickening performance of a mesh filtration system: the mesh opening sizes of 100-500 microm, and the sludge (3,000-9,000 mg-SS/L) was obtained from a domestic wastewater treatment facility. The filtration was carried out only under the hydraulic pressure between the water level and the effluent port connected to the mesh filter module. The sludge reduction rates were in the range of 85-95% for 6-7 h; the initial filtration rate was very high, but the rate decreased with a decrease in hydraulic pressure due to the reduction of the water level in the vessel. In addition, the effluents (passed through the mesh) contained very low SS and could be directly discharged into the environment.

Facility Design and Construction↗
PubMed1998

Preparation of a new thermo-responsive adsorbent with maltose as a ligand and its application to affinity precipitation.

A thermo-responsive polymer on which maltose was covalently immobilized as an affinity ligand was newly synthesized for purification of thermolabile proteins from the crude solution by affinity precipitation. Among the thermo-responsive polymers synthesized as carriers for adsorbent, poly(N-acryloylpiperidine)-cysteamine (pAP) has a lower critical solution temperature (LCST) of around 4 degrees C, at which its solubility exhibits a sharp change. Adsorbent for affinity precipitation was prepared by combining pAP with maltose using trimethylamine-borane as a reducing reagent. This adsorbent (pAPM) obtained showed a good solubility response: pAPM in the basal buffer (pH 7.0) became soluble below 4 degrees C and was completely insoluble above 8 degrees C. The affinity precipitation method using pAPM consisted of the following four steps: adsorption at 4 degrees C, precipitation of the complex at 10 degrees C, desorption by adding the desorption reagent at 4 degrees C, and recovery of a target protein at 10 degrees C. In the affinity precipitation of Con A from the crude extract of jack bean meal, 82% of Con A added was recovered with 80% purity by addition of 0.2 M methyl-alpha-D-mannopyranoside as a desorption reagent. In the repeated purification of Con A from the crude extract, pAPM could be satisfactorily reused without decrease in the affinity performance. Moreover, when pAPM was used for the purification of thermolabile alpha-glucosidase from the cell-free extract of Saccharomyces cerevisiae, 68% of total activity added was recovered and the specific activity per amount of protein of the purified solution was enhanced 206-fold higher than that of the cell-free extract without thermal deactivation of the enzyme.

Adsorption↗
PubMed1997

Identification of human skin from tissue fragments left in various conditions using an enzyme immunoassay for squamous cell carcinoma-related antigen.

We investigated the possibility of identification of human skin left under various conditions using our original enzyme immunoassay (EIA) for squamous cell carcinoma-related (SCC) antigen. The antigen could be detected in specimens under the following conditions : purified or dried at room temperature for at least 12 months, immersed in fresh water at room temperature for 3 weeks and heated at 100 degrees C for 72 h.

Antigens, Neoplasm↗
PubMed1996

Identification of human skin from a tissue fragment by detection of squamous cell carcinoma-related antigen using an enzyme immunoassay.

A new method of identifying human skin from a tissue fragment by detection of squamous cell carcinoma-related (SCC) antigen, using an enzyme immunoassay, was developed. When an extract was prepared from 0.1 g human skin homogenized with 1 ml of phosphate buffered saline, this method was able to detect SCC antigen in extracts diluted 10(2)-fold. There was no difference in the detection limit between individuals. Species specificity was good, and there was no cross reaction observed with skins from animals. Our method could also discriminate between skin and other organs or tissues, except for esophagus and lung. A practical case to which this method was applied is presented.

Adult↗
PubMed1996

Ginsenosides increase secretion of lipoprotein lipase by 3T3-L1 adipocytes.

Treatment of 3T3-L1 adipocytes with either an oleanolic acid glycoside or a 20(S)-protopanaxatriol glycoside increased the secretion of lipoprotein lipase activity into the medium dose-dependently. At a concentration of 100 micrograms/ml, ginsenosides Ro, Re, Rg1, and Rh1 increased the secretion of lipase activity into the medium by 119, 107, 56, and 32%, respectively. The ratio of lipase activity in the medium to cellular lipase activity was 4.7% in control cells and 8.6% in ginsenoside Ro-treated cells, 8.3% in ginsenoside Re-treated cells, 7.0% in ginsenoside Rg1-treated cells, and 6.3% in ginsenoside Rh1-treated cells. Ginsenoside Rb2, which is a 20(S)-protopanaxadiol glycoside, increased the secretion of lipase activity by 16% at 25 micrograms/ml, and the ratio of lipase activity in the medium to cellular lipase activity was higher in ginsenoside Rb2-treated cells than in control cells. However, at 100 and 200 micrograms/ml, ginsenoside Rb2 decreased the secretion of lipase activity in parallel with cellular lipase activity. Ginsenoside Rd also decreased the secretion of lipase activity in the same dose-dependent manner. Thus, the effective dose for the secretion of lipoprotein lipase activity with ginsenosides varies with their aglycone structure.

3T3 Cells↗
PubMed1996

Identification of menstrual blood by the simultaneous determination of FDP-D dimer and myoglobin contents.

FDP-D dimer (D-D) and myoglobin concentrations in peripheral, menstrual and postmortem blood/bloodstains were determined. The mean plasma concentrations of D-D in peripheral, menstrual and postmortem blood were 0.047, 102 and 220 micrograms/ml and those of myoglobin were 0.028, 0.066 and 727 micrograms/ml respectively. The mean D-D concentration in menstrual bloodstains was about 200 times higher than in peripheral bloodstains. The myoglobin contents in both bloodstains were similar. The mean myoglobin content in postmortem bloodstains was about 4000 times higher than in menstrual bloodstains. By the simultaneous determination of D-D and myoglobin contents, blood or bloodstains containing large amounts of D-D and only a small amount of myoglobin could be identified as menstrual blood.

Blood Specimen Collection↗
PubMed1995

The long amino-terminal tail domain of annexin XI is necessary for its nuclear localization.

Annexin XI is a newly identified annexin which localizes mainly in the nucleus of rat embryonic fibroblasts. There are no typical nuclear localization signals (NLS) in the molecule. To define the region responsible for its nuclear localization, a series of mutants and chimeric cDNA were constructed. These were transiently expressed in COS-7 cells, and the subcellular distributions of the mutants and chimeric proteins were determined by indirect immunofluorescence microscopy. Wild-type annexin XI was located predominantly within the nucleus. Deletion of the N-terminal tail domain (residues 3-196) changed the distribution of the protein from the nucleus to the cytoplasm whereas deletion of the C-terminal core domain (residues 208-504) still kept the protein sorting to the nucleus. Three other mutants lacking 60-80 amino acids in the N-terminal region (residues 3-61, 61-115, and 115-197, respectively) no longer efficiently imported into the nucleus. Furthermore, Escherichia coli beta-galactosidase polypeptide was efficiently localized to the nucleus only when fused with the whole N-terminal region of annexin XI (residues 1-207), not with part of the N-terminal region. In primary cultured rat hepatocytes, annexin XI was distributed in the cytoplasm but not in the nucleus. These results suggest that the whole N-terminal tail domain of annexin XI is necessary and sufficient for its nuclear localization, and may function as NLS in a cell-type specific manner.

Animals↗
PubMed1995

Identification of human skeletal muscle from a tissue fragment by detection of human myoglobin using a double-sandwich ELISA.

A method for identifying human skeletal muscle by detection of human myoglobin using a double-sandwich ELISA was developed. When an extract was prepared from 0.1 g skeletal muscle homogenized with 10 ml PBS, this method was able to detect human myoglobin in extracts diluted 10(4)-fold. There was no difference in the detection limit between individuals or sites of origin of skeletal muscles. Species specificity was good and no cross reaction occurred with skeletal muscle from other animals except the gorilla. Our method could also discriminate between skeletal muscle and other organs or tissues except the heart. Human myoglobin could be detected in skeletal muscles under the following conditions: putrefied at room temperature for 5 months, dried at room temperature for 11 months, heated at 100 degrees C for 72 h and immersed in fresh water at room temperature for 6 days. Two practical cases to which this method was applied are presented.

Adult↗
PubMed1995

Expression of cytokine genes during liver regeneration after partial hepatectomy in rats.

In the present study to demonstrate the relationship between cytokines and liver regeneration we investigated by Northern blot hybridization the cytokine gene induction in the regenerating liver and several other organs (spleen, lung, and kidney) in the rat after partial hepatectomy (PH). We also examined whether Kupffer cells and the spleen are involved in the induction of cytokine mRNA in the regenerating liver. Both IL-1 alpha and beta mRNA increased transiently 1/2 to 1 hr after PH in nonparenchymal cells (NPC) of the regenerating liver; they reached a maximum before the peak of hepatocyte DNA synthesis. PH also induced a slight, but significant, gene expression of IL-1 in lung and kidney in the early postoperative period. TNF-alpha mRNA increased gradually in the spleen, but not the liver, of partially hepatectomized rats at 3 to 12 hr and then reached a peak at 24 hr after PH. IL-6 transcripts were not detected in the regenerating liver, spleen, lung, or kidney during liver regeneration. In contrast, no cytokine gene expression was induced in any of these four organs during the first 3 days after sham operation or unilateral nephrectomy. When Kupffer cell activity was suppressed by gadolinium chloride pretreatment, or when splenectomy was performed 24 hr before PH, the constitutive IL-1 alpha and beta mRNA expressions in NPC of the normal rat liver were completely suppressed. In conclusion, the present study demonstrates, for the first time, the specific kinetics of cytokine gene expression in the liver, spleen, lung, and kidney after PH.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Participation of hepatic macrophages and plasma factors in endotoxin-induced liver injury.

The present study was designed to investigate the mechanism responsible for endotoxin-induced liver injury, based on the working hypothesis that hepatic macrophages activated by endotoxin play a key role in the development of this injury. At both the protein and the transcription levels, the intravenous administration of endotoxin was shown to have increased the capacity of hepatic macrophages to produce chemical mediators. To inhibit the function of hepatic macrophages, gadolinium chloride (GdCl3), a specific inhibitor of resident hepatic macrophages, was preadministered to rats before endotoxin injection. GdCl3 reduced the elevated glutamic oxaloacetic transamiase and lactate dehydrogenase serum levels produced by endotoxin treatment, suppressed the increased mRNA expression of tumor necrosis factor (TNF-alpha) produced in liver nonparenchymal cells by endotoxin, and then improved the survival rate of lipopolysaccharide-injected rats. These results indicated that hepatic macrophages played a crucial role in liver injury and that TNF-alpha was the most likely factor implicated in the development of endotoxin-induced liver injury. Furthermore, we found that liver injury did not progress during perfusion of endotoxin-pretreated extirpated liver with lactate Ringer's solution, whereas liver perfused with plasma developed remarkable hepatic impairment, which was inhibited almost completely by GdCl3-pretreatment; moreover, addition of heparin to the perfusate also prevented this deterioration. Thus, the present study showed that the activation of hepatic macrophages and factors in the plasma were two essential elements in the occurrence and development of endotoxin-induced liver injury.

Animals↗
PubMed1994

Discrimination between postmortem and antemortem blood by a dot-ELISA for human myoglobin.

A method for discriminating between postmortem and antemortem blood from bloodstains by detection of human myoglobin using a dot-ELISA was devised, and its applicability to forensic practice was investigated. This method exploits the high amount of myoglobin present in postmortem blood in comparison with that in antemortem blood. Our dot-ELISA was able to detect human myoglobin from bloodstains containing more than 10 micrograms/ml myoglobin, the level commonly observed in postmortem blood. Using this method, 10 stains of postmortem blood and 10 of antemortem blood were all identified correctly. A one-year-old stain made of postmortem blood and a stain of bloody fluid obtained from a severely putrefied body 4 months after death were identified as postmortem blood by this method. Two practical cases for which this method was applied are presented.

Adult↗
PubMed1994

Identification of the thromboxane A2 receptor in hepatic sinusoidal endothelial cells and its role in endotoxin-induced liver injury in rats.

The presence of the thromboxane A2 receptor in sinusoidal endothelial cells was investigated and its pathogenic role in endotoxin-induced liver injury examined. The receptor was measured with a binding assay using a specific thromboxane A2 receptor antagonist, [3H]S-145. Scatchard analysis of the binding indicated the presence of a single class of high-affinity binding sites with a dissociation constant of 5.00 +/- 0.96 nmol/L, a maximal binding of 22.85 +/- 2.71 fmol/10(6) cells and 13.80 +/- 1.60 x 10(3) binding sites per cell. The addition of a cyclooxygenase inhibitor, indomethacin, during the cell preparation increased the maximal binding value and the number of binding sites of 37.34 +/- 3.01 and 22.50 +/- 1.80 x 10(3) sites/cell, respectively. The binding was displaced by various thromboxane A2 analogs such as ONO-3708 and STA2 but was not effectively competed for by other prostaglandins. Endotoxin injection reduced dissociation constant, maximal binding and the number of binding sites in sinusoidal endothelial cells to 3.49 +/- 0.87 nmol/L, 6.03 +/- 0.64 fmol/10(6) cells and 3.65 +/- 0.39 x 10(3) sites/cell, respectively. A cyclooxygenase inhibitor and a Kupffer cell inhibitor added before endotoxin treatment significantly prevented the reduction in the number of thromboxane A2 receptors. It is possible that these effects were due to a reduction in the agonist-induced internalization of the thromboxane A2 receptor brought about by the prevention of thromboxane A2 production. Preadministration of both a cyclooxygenase inhibitor and a thromboxane A2 receptor antagonist attenuated the degree of endotoxin-induced liver injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Immunologic activation of hepatic macrophages in septic rats: a possible mechanism of sepsis-associated liver injury.

To investigate the pathogenesis of liver dysfunction accompanying intra-abdominal sepsis, we used rats with cecal ligation and punctures (CLP) and examined the expression of the inflammatory cytokines IL-1-alpha, IL-1-beta, and TNF-alpha, as well as the expression of a cell adhesion molecule, ICAM-1, in the liver. We also examined the expression of Ia antigen and interleukin-2 receptor (IL-2R) on hepatic macrophages. Hepatic macrophages isolated from rats 24 hours after CLP exhibited significantly higher IL-1 and TNF activity than those from control rats. Hepatic macrophages isolated from rats 72 hours after CLP exhibited the maximal IL-1 and TNF activity. In the hepatic nonparenchymal cells, IL-1-alpha mRNA was induced 1 hour after CLP, increasing to the maximal level 3 hours after CLP, whereas IL-1-beta mRNA was induced gradually, reaching a peak 6 hours after CLP. ICAM-1 mRNA reached a peak 3 hours after CLP. Induction of TNF-alpha mRNA was not detected by the present Northern blot analysis. Seventy-two hours after CLP, the proportions of hepatic macrophages expressing Ia antigens and IL-2R were increased significantly, as revealed by the flow cytometric analysis. In conclusion, the present study showed that hepatic macrophages are in an activated state in sepsis as indicated by their increased production of inflammatory monokines and their increased expression of immunomodulatory surface molecules. Further, we demonstrated the sequential induction of the mRNA of the various inflammatory cytokines and ICAM-1. These findings strengthen the notion that these cytokines are relevant to the pathogenesis of liver injury associated with sepsis.

Animals↗
PubMed1992

Effect of PGE2 on interleukin-1 and superoxide release from primary-cultured human hepatic macrophages.

In order to learn more about how human hepatic macrophages function, we analyzed the effect of exogenous PGE2 on the amounts of interleukin-1 (IL-1) and superoxide (O2-) released from primary-cultured human hepatic macrophages (HHM phi). When endogenous PGE2 production was blocked by indomethacin, exogenous PGE2 reduced IL-1 release from HHM phi in a dose-dependent manner, whereas it tended to increase O2- release from HHM phi. These results may suggest the probable contribution of PGE2 in regulating HHM phi mediator release in vivo.

Cells, Cultured↗
PubMed1991

[Study on the pulmonary tuberculosis in the elderly].

A study was made for 13 cases of patients over 80 years of age who received medical treatment for tuberculosis. Four factors of onset of tuberculosis at old age were indicated. 1. No opportunity for examination of X-ray for old generation. 2. Atypical shadows on the chest X-ray film. 3. Low stress tolerance. 4. Exacerbation of old tuberculosis during the treatment of other diseases. The results suggest the possibility of increasing pulmonary tuberculosis among the elderly persons in the near future.

Aged↗
PubMed1990

[A case of invasive thymoma with pulmonary tuberculosis].

A 68-year old male was referred to our hospital for the treatment of pulmonary tuberculosis. Chest X-ray film revealed left diffuse pleural thickening. Treatment of pulmonary tuberculosis was started with streptomycin, isoniazid and rifampicin. Three months later, although smear and culture of the patient's sputum became negative for M. tuberculosis, he started to complain of dyspnea on exercise and left chest pain. Biopsies of a pleural tumor and a left subclavicular lymph node were done and a diagnosis of invasive thymoma with pleural dissemination and bone and lymph node metastasis was established. After three cycles of combination chemotherapy consisting of cyclophosphamide, adriamycin and vincristine, left chest pain disappeared and pleural thickening showed shrinkage.

Aged↗
PubMed1989

Effects of the kallikrein-kinin system on phasic coronary vasospasm in dogs.

It is well known that kinins are liberated from kininogen in blood during angina attack to maintain blood flow in coronary artery. We examined the effects of bradykinin, one of kinins, on the coronary artery other than vasodilation. The isolated canine coronary artery ring was suspended in gassed (95% O2, 5% CO2) Krebs-Henseleit buffer at 37 degrees C in vitro. The experimental phasic contraction of coronary artery was induced by 6 x 10(-4)M of 3,4-diaminopyridine which decreases K conductance (Y. Uchida, Jpn. Circ. J: 49, 128, 1985). The effect of bradykinin and other substances on the cycle length of contraction (CL), the peak tension of contraction phase (PT) and the tension during relaxation phase (RT) were observed. The phasic contraction was eliminated by 10(-7)M nifedipine and 10(-6)M diltiazem which block voltage dependent Ca channels. These Ca blockers reduced PT, but slightly increased CL, and weakly reduced RT. The phasic contraction was also eliminated by 10(-6)M bradykinin. However, bradykinin, unlike Ca blockers, did not reduce PT, but markedly prolonged CL and decreased RT significantly. This inhibition mode was very similar to those of nicorandil which increases K conductance. These data suggest that bradykinin plays a protective role in coronary vasospasm, and this antivasospasm effect may be mediated through the increase in K conductance.

Animals↗