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Biomedical subjects

F Kondo

Publications and source records attributed to F Kondo.

At least 73 records · Page 4Linked to original sources
PubMed1997

High-performance liquid chromatographic analysis of bilirubin and biliverdin from jaundiced broilers.

A sensitive and rapid high-performance liquid chromatographic (HPLC) method was developed and used for the simultaneous determination of bilirubin and biliverdin in pericardial fluid samples collected from broilers at a poultry inspection site. A photodiode array detector distinguishing the bilirubin (UV 450 nm) and biliverdin (365 nm) was used as an analytical detector for HPLC system. An internal-surface reversed-phase silica support column was used, and the mobile phase consisted of acetonitrile: 0.5 M Tris HCl buffer (20:80, pH 7.2). Bilirubin was detected from all of the jaundiced pericardial fluid samples, and a small amount of biliverdin was detected with bilirubin in some samples. These jaundiced broilers had hepatic or bile duct lesions similar to those found in edible animals. From these results, a working definition of jaundiced broilers for poultry inspection sites was suggested: bilirubin is detectable from pericardial fluid and the carcass is in a state of yellow color change.

Animals↗
PubMed1996

Inhibition of peritoneal dissemination of colon carcinoma in syngeneic mice immunized with interleukin-2-producing cells.

We have examined the antitumor effect of murine colon carcinoma cells engineered to produce human interleukin-2 (IL-2) in syngeneic mice. Subcutaneous inoculation of retrovirally-transduced cells with IL-2 gene formed small tumors, but they became regressed spontaneously. Consequently, the inoculated mice showed prolonged survival. Histological examination of the tumors derived from IL-2-producers revealed predominant infiltration of macrophages around tumor necrotic masses. Thus, inoculation of IL-2-producing cells could protect the mice from subsequent subcutaneous or intraperitoneal challenges with wild-type cells, suggesting the induction of acquired immunity due to the effect of tumor vaccination.

Animals↗
PubMed1996

Antitumor effect induced by the expression of granulocyte macrophage-colony stimulating factor gene in murine colon carcinoma cells.

Murine colon carcinoma cells which secrete several kinds of cytokine after retroviral transduction with corresponding genes, were examined for their antitumor effects in syngeneic mice. The mice inoculated with granulocyte macrophage-colony stimulating factor (GM-CSF) producer cells showed not only prolonged survival but also reduced tumorigenicity. The antitumor effect caused by the expression of interleukin-4 was less than that of GM-CSF, and interleukin-6 producer cells did not show any effects on the survival of the host animals. Histological examination of the GM-CSF-producing tumor revealed predominant infiltration of neutrophils and necrotic change of the tumor. The present study indicates the feasibility of cancer gene therapy with the expression of GM-CSF gene in tumor cells.

Animals↗
PubMed1996

Murine colon carcinoma cells engineered to produce human interleukin-2 induce tumor-specific anti-tumor response.

Murine colon carcinoma cells (colon 26) transduced by a retrovirus vector with the human interleukin-2 (IL-2) cDNA were studied for their tumorigenicity. Although cell growth in vitro was not affected by integration of the IL-2 gene, s.c. tumors of IL-2-producing colon 26 cells (H2) in syngeneic mice regressed spontaneously after producing small masses. Histological examination of the sites of tumor rejection revealed predominant infiltration of macrophages around the tumor necrotic mass. Subsequent challenge with parent colon 26 cells, but not with Meth A cells (fibrosarcoma of the same genetic background), did not result in tumor formation in mice which had been protected against H2 cells. Inoculation of H2 cells into syngeneic nude mice resulted in tumors with a retarded growth rate. Taken together, T cell-dependent, tumor-specific immunity is obtained by local IL-2 secretion around colon tumors, and this experimental animal model gives us a clue(s) for investigating host anti-tumor responses by cytokine production.

Animals↗
PubMed1996

Detection and identification of microcystins in the drinking water of Haimen City, China.

Cyanobacterial toxins, microcystins, have a potent tumor-promoting activity. We investigated the level of microcystins in drinking water collected from 1992 to 1994 in Haimen City, China, where people who drink pond ditch water usually incurred a high incidence rate of hepatocellular carcinoma compared with those who drink well water. High-performance liquid chromatography, liquid chromatography/mass spectrometry (LC/MS), and protein phosphatase inhibition assay (pp assay) were used to identify and quantify the microcystins. Microcystin LR and [D-Asp3]microcystin LR were detected in 2 of 50 samples at a concentration less than 100 ng/L by LC/MS in 1992. Although no microcystins were found by the chemical method in 1993, 6 of 7 samples except for 3 tap water samples showed an approximate amount of 100 ng/L by using the pp assay in 1994. The obtained results supported the epidemiological results reported by Yu.

Bacterial Toxins↗
PubMed1996

Microcystin levels during 1992-95 for Lakes Sagami and Tsukui-Japan.

Toxic cyanobacterial blooms have been frequently observed in Lakes Sagami and Tsukui, Kanagawa Prefecture, Japan, which are used as drinking and recreational water sources. As the first step toward the control and removal of cyanobacterial toxins, the present study evaluated the microcystin level in these lakes. Our established method using HPLC and LC/MS to pursue trace amounts of microcystins was applied to the determination of microcystins within cyanobacteria cells and in water. We could determine precisely the intracellular and extracellular microcystin level in the water environment during 1992-95. Microcystins RR, LR, and YR were detected at 0.02-2.64 micrograms/L in cell-free water and at 0.02-378 micrograms/L in the cells. Although there were many cases in which microcystin concentrations in the cells exceeded the proposed guideline level (1 microgram/L), there was only one example of this happening in cell-free water samples. Because the present monitoring indicated that the amount of microcystins detected in water was much less than that estimated in cells, the release of microcystins from the cells and their stability in lake water were examined in the dark. The resulting toxins persisted at the same concentration level for 14 days and the microcystin concentrations steadily declined, showing that biodegradation using aquatic natural bacterial flora is an effective detoxification process under natural conditions.

Biodegradation, Environmental↗
PubMed1996

Mass spectrometric screening method for microcystins in cyanobacteria.

A screening method for microcystins in cyanobacteria, which consists of the formation of 3-methoxy-2-methyl-4-phenylbutyric acid as an oxidation product of microcystins by ozonolysis, and detection of 3-methoxy-2-methyl-4-phenylbutyric acid by thermospray-liquid chromatography/mass spectrometry or electron ionization-gas chromatography/mass spectrometry using selected ion monitoring, was developed. The ozonolysis made it possible to significantly reduce the formation times of 3-methoxy-2-methyl-4-phenylbutyric acid because the previously required extraction, clean-up and other procedures could be entirely eliminated. The resulting intact 2-methyl-4-phenylbutyric acid was directly analyzed by thermospray-liquid or electron ionization-gas chromatography/mass spectrometry, and the procedures from ozonolysis to analysis of microcystins at the pmole levels were performed within only 30 min. The calibration curves obtained by thermospray-liquid or electron ionization-gas chromatography/mass spectrometry analysis showed a linear relationship from 14 to 830 pmole and from 2.5 to 100 pmole of microcystin-LR, respectively. The method was applied to the detection and determination of the total amount of microcystins in bloom and cultured samples, showing that it provided a means of not only screening for microcystins but of their accurate quantitation.

Calibration↗
PubMed1996

Pyridinoline collagen cross-links in patients with chronic viral hepatitis and cirrhosis.

BACKGROUND/AIMS: The mature form of collagen cross-linking increases the resistance of collagen to degradative enzymes, and thus renders the protein in the fibrotic lesions extremely stable and the fibrosis virtually irreversible. It is crucial to elucidate the extent of cross-linking in fibrotic and cirrhotic livers if we are to control the subsequent removal of the excessive deposited collagen, whether by natural enzymes or induced by therapy. We aimed to quantitate pyridinoline, a mature form of the cross-linking, in normal control livers, viral fibrotic livers with various degrees of fibrosis and viral cirrhotic livers. METHODS: Needle liver biopsy samples from 75 patients with chronic viral hepatitis and 13 patients with viral liver cirrhosis, and six normal control livers were analyzed. Collagen and pyridinoline contents were determined by high-performance liquid chromatography. RESULTS: Significantly higher levels of pyridinoline cross-links per collagen molecule were found in the viral cirrhotic livers (0.60 [0.46, 0.65] pmol/pmol of collagen; median [25%, 75%]) compared with those in normal livers (0.39 [0.24, 0.43] pmol/pmol of collagen, p = 0.03491). But no differences were found in levels between cirrhosis and chronic hepatitis with various degrees of fibrosis. These data suggest that liver collagen may be susceptible to degradation to a similar degree in viral cirrhosis and in chronic viral hepatitis. CONCLUSION: The extent of the pyridinoline cross-linking of hepatic collagen does not seem to be responsible for the irreversibility of viral liver fibrosis.

Adult↗
PubMed1996

Detection and identification of metabolites of microcystins formed in vivo in mouse and rat livers.

The hepatic metabolism of microcystins (MCs), potent cyclic peptide hepatotoxins produced by cyanobacteria, was studied by i.p. injection in mice and rats. An immunoaffinity purification method using an anti-MC-LR monoclonal antibody showed a remarkable effect on the removal of contaminants in the hepatic cytosol and enabled us to analyze MCs and their metabolites by HPLC and Frit-FAB LC/MS. At 3, 6, and 24 h post-injection of MC-RR, a small percent of the applied dose was detected in all of the mouse livers together with several metabolites. Among them, GSH and Cys conjugates of MC-RR were identified at 3 and 24 h, respectively, by comparison with the chemically prepared standards, indicating that the thiols of GSH and Cys nucleophilically bound to the Mdha moiety of MCs. Another metabolite was presumed to be formed by both epoxidation followed by hydrolysis and sulfate conjugation in the Adda moiety and GSH conjugation in the Mdha moiety. In rat livers, MC-LR showed almost the same behavior as that of MC-RR in mouse livers. These results suggest that the conjugation of GSH with MCs may play a role in the metabolic pathway leading to detoxification of MCs.

Animals↗
PubMed1996

Detection of hepatocellular carcinoma after interferon therapy for chronic hepatitis C: clinical study of 26 cases.

The clinical findings in 26 patients in whom hepatocellular carcinoma (HCC) was detected after the start of interferon (IFN) therapy for chronic hepatitis C were analysed. Histological study before IFN therapy showed that 34.6% of patients were categorized as stage 3 (septal fibrosis with architectural distortion; the 0-4 scale) and 80.8% demonstrated at least some evidence of septal fibrosis or more advanced features. The AFP levels examined before IFN therapy were more than 20 ng/mL in 13 patients (84.6% of those studied). One of 26 patients had a complete response to IFN therapy, while six of 26 patients had only a partial response. HCC was detected within 1 year after the start of IFN therapy in 76.9% of patients. Thus, the possibility of the early occurrence of HCC or its existence at the time of therapy should be seriously considered when IFN therapy is contemplated. Patients with stage 3 or 3-4 histology may already have a small undetectable HCC before IFN therapy. Thus, for this reason, every patient treated with IFN should be examined at short regular intervals for the development of HCC during and after IFN therapy.

Adult↗
PubMed1996

Rapid analysis of four bilirubins in domestic animal sera using high-performance liquid chromatography.

A rapid method was developed to analyze delta-bilirubin (B delta), diconjugated bilirubin (DCB), monoconjugated bilirubin (MCB), and unconjugated bilirubin (Bu) by direct injection of sera using high-performance liquid chromatography (HPLC) with an internal-surface reversed-phase silica support (ISRP) column. Sharp bilirubin peaks were obtained using a simple mobile phase of acetonitrile: 0.5 M Tris-HCl buffer (20:80, v/v, pH 7.2). A variable-wavelength detector set at 450 nm, 0.01 absorbance unit full scale (AUFS), and a recorder set at 4 mm/min were used for detection. Peaks for B delta, DCB, MCB and Bu appeared at 4.4, 6.4, 9.2 and 14.5 min, respectively, in human serum from subject with obstructive jaundice which was used as a bilirubin standard throughout this experiment. The mean recovery rate after direct addition of Bu in swine serum was 91.9% and that of DCB was 95.9%. When sera from icteric cattle, pigs and horses were analyzed using the direct injection technique, four bilirubin peaks were obtained and there was reliable correlation between the sum of the bilirubin peak heights observed on HPLC and the total bilirubin value measured by a standard reference procedure.

Animals↗
PubMed1996

[Comparison of clinical effects between granisetron alone and combination of granisetron and methylprednisolone against the nausea and vomiting induced by CDDP chemotherapy--comparative study by the cross-over trial. University of Tsukuba Antiemetics Study Group].

A cross-over clinical trial was carried out to compare the antiemetic effect and safety between granisetron alone (40 micrograms/kg) and the combination of granisetron and methylprednisolone (MP: 10 mg/kg) in urological cancer patients treated with cisplatin. Forty-eight courses were given with granisetron alone and 47 courses with both granisetron and MP. The antiemetic effect of nausea and vomiting was evaluated in the acute emetic phase. during the 24 hours following the CDDP administration, and in the delayed emetic phase, 2 to 7 days after the administration. Combination therapy of granisetron and MP demonstrated a greater antiemetic effect during the 72 hours following the CDDP administration than by granisetron alone. But there was no significant difference in antiemetic effect between combination therapy and granisetron alone after the 3rd day. Combination therapy also demonstrated more efficacy in complete antiemetic effect, with no emesis and less than moderate nausea, than by granisetron alone. Both treatments showed no side effects and were safe.

Aged↗
PubMed1996

Rapid and quantitative analysis of bilirubin in equines by high-performance liquid chromatography.

Rapid and quantitative analytical methods for bilirubin using high-performance liquid chromatography (HPLC) with UV detection were developed for samples from equines at a meat inspection site. Sharp HPLC peaks for bilirubins, unconjugated bilirubin (UCBL) and conjugated bilirubin (CBL), were obtained using a simple mobile phase of methanol:0.5 M Tris-HCl buffer (65:35, v/v, pH 7.4). A variable wavelength detector set at 450 nm, 0.01 AUFS and a recorder set at 4 cm/min were used for detection. Peaks for UCBL and CBL occurred at 7.1 min and 4.9 min, the lower limits of detection ranged between 0.16 and 0.78 microgram/ml, respectively. Orange II, for which the retention time was 3.6 min, was selected as an internal standard. When the samples were analysed from healthy equines and those suspected of being jaundiced due to a yellow colour change in the carcasses, only UCBL peaks were recognized, and CBL peaks were never obtained. Aqueous humour is a very common sample at meat inspections but UCBL or CBL peaks were all absent in both healthy and clinical samples from equines. There were reliable correlations between UCBL peaks (microV) using HPLC and total bilirubin value (mg/dl) measured by the total bilirubin assay kit in serum. A correlation between peak height (microV) on HPLC from serum samples and that of pericardial fluid samples was obtained.

Animals↗
PubMed1995

Reliable and sensitive method for determination of microcystins in complicated matrices by frit-fast atom bombardment liquid chromatography/mass spectrometry.

A reliable and sensitive method for determination of hepatotoxic microcystins in complicated matrices by frit-fast atom bombardment liquid chromatography/mass spectrometry (Frit-FAB LC/MS) is described. Immonium ions of constituent amino acids, which were obtained together with molecular ion species by FAB mass spectral analysis of standard microcystins RR, YR, LR, and [D-Asp3] and [Dha7]microcystins LR using flow injection system composed of Frit-FAB probe, showed potential for reliable identification of microcystins by Frit-FAB LC/MS. Frit-FAB LC/MS using a microbore column provided not only the baseline separation of standard microcystins RR, YR, and LR but 200-fold higher sensitivity than that using conventional column. Furthermore, when a selected ion monitoring (SIM) technique was used, the detection limits of microcystins RR, YR, and LR were 300, 350, and 400 pg, respectively, at a signal-to-noise ratio of 5:1, and calibration curves of each microcystin showed a linear relationship from 2 ng to 50 ng. Finally, identification and quantitative analyses of microcystins in water samples were carried out.

Chromatography, Liquid↗
PubMed1995

Stability of microcystins from cyanobacteria--II. Effect of UV light on decomposition and isomerization.

Microcystins are very potent hepatotoxins and strong liver tumor promoters produced by cyanobacteria, and their occurrence has been reported all over the world. They could threaten human health when toxic Microcystis occurs in water supply reservoirs. In this study, we examined the stability of microcystins during photolysis with UV light. The toxins were easily decomposed by UV light at wavelengths around the absorption maxima of the toxins and the decomposition depended on the intensity of the light. The half-life of microcystin LR by 147 microW/cm2 UV irradiation was 10 min, and the toxin was completely decomposed by 2550 microW/cm2 UV after 10 min. When the toxins were irradiated with weaker UV light, isomerization was also observed by a different mechanism from that during photolysis by sunlight and pigment, and several products including three geometrical isomers of the conjugated diene of Adda were detected. Microcystin RR showed almost the same behavior as that of microcystin LR under the same conditions. Since no noxious products were formed in the present study, a water treatment including UV irradiation is very possible for removing microcystins from raw water.

Chromatography, High Pressure Liquid↗
PubMed1995

Immunohistochemical detection of aberrant p53 expression in hepatocellular carcinoma: correlation with cell proliferative activity indices, including mitotic index and MIB-1 immunostaining.

We analyzed the p53 expression immunohistochemically in 50 specimens of hepatocellular carcinoma (HCC) using two monoclonal antibodies (DO7 and PAb1801) and one polyclonal antibody (CM1), which recognize both wild and mutant type p53 proteins and can be used for paraffin-embedded sections. Fifteen of the 50 HCC specimens (30%) showed p53 expression localized at tumor nuclei, and this expression was significantly more frequent in HCCs with histologically lower differentiation. Except for serum titers of alpha-fetoprotein, the p53 expression had no statistically significant correlation with clinicopathological parameters, including hepatitis virus infection, tumor size, and background liver diseases. Conversely, the cell proliferative activities of tumor cells as assessed by mitotic index and immunostaining for MIB-1 were well correlated with the grade of histological differentiation. Moreover, MIB-1 immunostaining was shown to be useful in distinguishing well differentiated HCC from hepatocytes in chronic liver diseases. It also was shown that p53 expression was strongly associated with cell proliferative activity. Our results indicate that p53 expression takes place in the late stage of tumor progression and is related to the high malignant potential of HCCs.

Antibodies, Monoclonal↗
PubMed1995

Determination of sulfamethazine residue in chicken serum and egg by high-performance liquid chromatography with chemiluminescence detection.

A sensitive method that involves high-performance liquid chromatography with chemiluminescence detection is developed for the determination of sulfamethazine residue in samples of chicken serum and egg. Sulfamethazine is extracted from the samples and derivatized with fluorescamine. The derivatized samples are eluted by reversed-phase chromatography using a mixture of 10 mM potassium phosphate and 30% acetonitrile on a Nova-Pak C18 column. The post-column reagents in the chemiluminescence system are 1 mM bis[2-(3,6,9-trioxadecanyloxycarbonyl)-4-nitrophenyl] oxalate and 0.3M hydrogen peroxide in acetonitrile. The detection limit in the standard solution is 1 ng/mL, and the calibration curve is linear between 1 and 100 ng/mL. The recoveries of spiked samples (50 ppb) are 95.8 +/- 9.7% in chicken serum samples and 84.9 +/- 10.7% in egg samples. In actual sample analysis, the lowest detectable concentration of sulfamethazine (0.073 microgram/mL) was found at 48 h in serum and on day 9 (0.017 microgram/g) in egg after oral administration of a dose of 100 mg/kg body weight to hens.

Animals↗