Biomedical subjects

T Takatori

Publications and source records attributed to T Takatori.

At least 91 records · Page 5Linked to original sources

PubMed1992

Radioimmunoassays for melatonin using an antiserum raised against a novel antigen.

The highly specific antiserum to melatonin (MT) was produced, and the sensitivity and specificity of the radioimmunoassays (RIAs) using this antiserum was investigated. An immunogen was synthesized by binding 6-hydroxy-melatonin (6-OH-MT) to bovine serum albumin with a spacer of 6-bromohexanoic acid ethyl ester. Rabbits were immunized subcutaneously once a month with 1.0 mg of the immunogen for 7 months. The antiserum was characterized by a crossreactivity test by RIA using 125I-labelled MT. The antiserum specifically recognized MT but hardly did other analogues except for 6-OH-MT with a crossreactivity of only 0.4%. Two RIAs were established using [o-methyl-3H]MT and 2-[125I]iodo MT. In both RIAs, inhibition curves for MT were obtained in the range of 10 pg to 10 ng and 1-2 ng of MT inhibited the value of the assay at "0" by half. The similarity of the RIAs in sensitivity and inhibition by unlabelled MT is discussed on the basis of the structures of radioactive MTs and that of the immunogen.

Animals↗

PubMed1991

Insulin-like growth factor I rapidly induces tyrosine phosphorylation of a Mr 150,000 and a Mr 160,000 protein in highly metastatic mouse colon carcinoma 26 NL-17 cells.

Insulin-like growth factor I (IGF-I) stimulates the proliferation of highly metastatic NL-17 cells to a greater extent than poorly metastatic NL-44 cells, both of which are derived from mouse colon carcinoma 26. The NL-17 cells have been compared with NL-44 cells for the signal transduction pathway of IGF-I. IGF-I receptors of both cell types were identified by affinity labeling, and there was no significant difference between the two cell types in the amount or the autophosphorylation activity of the IGF-I receptors. However, when IGF-I-dependent tyrosine phosphorylation of cellular components was examined, remarkable tyrosine phosphorylation of proteins with molecular weights of 150,000 (pp150) and 160,000 (pp160) was found in NL-17 cells. In contrast, this phosphorylation stayed at significantly lower levels in NL-44 cells than in NL-17 cells. The phosphorylation of pp150 and pp160 was induced within 10 s after the addition of IGF-I and reached its maximal level by 30 s. After the removal of IGF-I, the phosphorylation of pp150 and pp160 was reduced to the basal level within 30 min. This phosphorylation was not induced by platelet-derived or epidermal growth factor. The pp150 and pp160 were not absorbed by wheat germ agglutinin-agarose. They were found in the soluble fraction of cytoplasm but not in the membrane or the cytoskeleton. The pp150 and pp160 might be endogenous substrates of IGF-I receptor kinase. These results suggest that tyrosine phosphorylation of pp150 and pp160 mediates the higher proliferative response of NL-17 cells to IGF-I.

Animals↗

PubMed1991

Determination of dimethyl sulphide in blood and adipose tissue by headspace gas analysis.

A method for the headspace analysis of dimethyl sulphide in blood and adipose tissue has been established. Blood (0.2 ml) or adipose tissue (0.5 g) with added dimethyl sulphide was sealed in a 10-ml vial using PTFE sheet to prevent escape of dimethyl sulphide from the headspace. Equilibration was performed at 60 degrees C for 4 h, and 20 microliters of gaseous phase sampled from the headspace was subjected to gas chromatography (with flame photometric detection). Calibration curves were prepared for the two samples. Linearity was observed in the range from 5-10 micrograms to 2 mg.

Adipose Tissue↗

PubMed1991

Fatality due to inhalation of dimethyl sulfide in a confined space: a case report and animal experiments.

A man was found dead in a tank where gaseous dimethyl sulfide (DMS) was present. The concentrations of DMS in the blood and tissue samples were measured by gas chromatography. Mice were experimentally exposed to various concentrations (5%-55%) of gaseous DMS in a confined space and the course of death and DMS distribution in the bodies were observed to obtain diagnostic criteria for DMS poisoning. As a result it was considered that the cause of death of the victim was consistent with a combination of DMS poisoning and asphyxia due to a hypoxic atmosphere.

Accidents, Occupational↗

PubMed1991

A comparative study of diazepam levels in bone marrow versus serum, saliva and brain tissue.

The distribution of diazepam in biological fluids and tissues of rats was examined 1, 2, 4 and 8 h after intraperitoneal administration by using a radioimmunoassay with specific anti-diazepam antibody. The diazepam levels in serum, saliva, brain and bone marrow decreased over a period of 2 h and levelled off 4 h after administration. The diazepam concentration in bone marrow was much higher than in serum, saliva and brain, suggesting an accumulation of diazepam in this tissue. This indicates that bone marrow could be a very useful material for the detection of diazepam in skeletonized remains. The diazepam concentrations in bone marrow, serum, saliva and brain showed a linear relationship (r = 0.860-0.997), indicating that a valid estimate of diazepam concentration in blood can be made from bone marrow samples.

Animals↗

PubMed1991

Regional variation in oral mucosal drug absorption: permeability and degree of keratinization in hamster oral cavity.

The regional permeability of oral mucosa to salicylic acid was investigated in vivo in hamsters along with histological variations, especially the degree of keratinization. Histological sections from six regions, i.e., sublingual mucosa, buccal mucosa, dorsum of tongue, ventral surface of tongue, labial mucosa, and cheek pouch mucosa, were prepared to assess the degree of keratinization. The area under the plasma concentration-time curve of salicylic acid following the administration of salicylic acid to the oral mucosa with a film dosage form and the thickness of stratum corneum of each site were in inverse proportion to each other, suggesting that the stratum corneum layer represents the principle barrier to drug absorption.

Absorption↗

PubMed1991

Development of monoclonal antibodies reactive with methamphetamine raised against a new antigen.

Monoclonal antibodies (McAbs) specific to methamphetamine (MA) were produced using p-amino MA coupled to bovine serum albumin (BSA) with glutaraldehyde (GA) as an immunogen and with conventional hybridoma techniques. Hybridoma clones secreting the McAbs were selected by an enzyme-linked immunosorbent assay (ELISA) system using both the above conjugate and BSA modified with GA as screening antigens. In the ELISA system were used avidin and biotinyl-alkaline phosphatase which converts nicotinamide adenine dinucleotide phosphate (NADP) into NAD. The final enzyme activity was determined using diformazan of nitroblue tetrazolium formed together with the NAD produced, alcohol dehydrogenase and phenazine methosulfate. The McAbs from 9 clones were characterized by a crossreactivity test using the ELISA. The McAbs recognized MA (100%), methoxyphenamine (8.0%), ephedrine (2.3%), but did not react with metylephedrine, amphetamine, OH-amphetamine, dimethylamphetamine, beta-phenylethylamine, norephedrine, phentermine and ranitidine. An inhibition curve for MA was obtained in the range of 0.75 to 50 ng.

Animals↗

PubMed1991

Production and characterization of monoclonal antibodies reactive with melatonin.

Monoclonal antibodies(moAbs) reactive with melatonin(MT) were produced using MT, coupled to bovine serum albumin(BSA) with the Mannich reaction, as immunogen and conventional hybridoma techniques. Hybridoma clones secreting the moAbs were selected by an enzyme-linked immunosorbent assay system using MT-carboxymethylchitin and BSA as screening antigens. The moAbs from 6 clones were characterized by a cross-reactivity test using radioimmunoassay with 125I-labelled MT. The moAbs recognized MT but hardly recognized other analogues except for N-acetylserotonin with a crossreactivity of 0.81%. An inhibition curve for MT was obtained in the range of 50 pg to 100 ng and 1.4 ng of MT inhibited the value of the assay by half. There is interference from some unknown source in human serum.

Adult↗

PubMed1991

Identification and characterization of three DNA-binding proteins on the promoter of the human MDR1 gene in drug-sensitive and -resistant cells.

In multidrug-resistant cell lines (K562/ADM), MDR1 was amplified and transcriptionally activated. But the mechanism of MDR1 expression is unknown in K562/ADM cells. A 131 bp DNA fragment upstream from the major cap site of MDR1 contained CAAT-like and GC-box-like motifs and showed promoter activity in a CAT expression assay, resulting in a 3.5-fold enhancement of MDR1 promoter activity in K562/ADM as compared with that in K562 cells. In the CAT assay using deletion mutants we found that sequences containing the CAAT-like motif and the GC-box-like motif were required for MDR1 proximal promoter activity. To understand the details of MDR1 transcription in K562/ADM cells we analyzed the interaction between the proximal promoter and DNA-binding protein(s). We have identified three DNA-binding proteins on the MDR1 promoter from K562/ADM and parental K562 cells. The first binding protein to the MDR1 promoter was NF-R1, which recognized the sequences containing the CAAT-like motif and the GC-box-like motif as revealed by using a gel mobility shift assay. The second protein was NF-R2, which bound to the sequence containing the CAAT-like motif. The third protein, which bound to the sequence containing the GC-box-like motif was designated NF-R3. NF-R2 and NF-R3 in the resistant cells formed different bands in the gel mobility shift assays as compared with those in the sensitive cells, respectively. The observed difference might be related to the transcriptional activation of MDR1 in K562/ADM cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1991

Immunohistochemical localization of paraquat in lung and brain.

In order to observe the localization and dynamics of paraquat in lung and brain, immunohistochemical approaches were conducted by using animals. Experimental paraquat-poisoned rats were sacrificed 3 hours, 12 hours, 24 hours, 3 days, 7 days and 10 days after intravenous administration of paraquat (5 mg/kg). In lung tissues, paraquat was localized in histiocytes, walls of blood vessels and bronchiolar epithelial cells from 3 hours to 10 days after the paraquat exposure, and interstitial pulmonary fibrosis was being developed with time. On the other hand, in brain tissues, paraquat was localized only in capillary walls and glial cells but not observed in nerve cells 10 days after the administration of paraquat.

Animals↗

PubMed1991

[Drug induced hepatitis following sevoflurane anesthesia in a child].

A new volatile anesthetic, sevoflurane, is widely used in Japan. We first report a patient who developed liver dysfunction following sevoflurane anesthesia. He had a resection of the bilateral extra toes at the age of eleven months. Although no problems occurred during the operation, he had serious liver dysfunction. Fourteen days after operation, serum GOT was elevated to the maximum of 836U. The pathogenesis is considered to be related to sevoflurane anesthesia, because viral hepatitis was excluded, and sevoflurane is considerably positive in lymphocyte stimulation test in contrast with antibiotics.

Anesthesia, Inhalation↗

PubMed1991

[A bibliographic discussion on the obstruction of arteries and the air passage in hanging].

Since conjunctival petechial haemorrhage and froth can occur when the cervical arteries and air passage are not obstructed or incompletely obstructed, it is useful to know whether they are closed or not in a suspended body when we estimate the cause of its death being due to hanging or being a disguise after killed by strangulation. We discussed their obstruction in hanging after references, as summarized in tables. Arterial obstruction: Classical data on the arterial obstruction (Brouardel, 1897; Schwarzacher, 1928) have not been cited with a definite description that the data were obtained in experiments on typical hanging. In typical hanging, carotid arteries are directly closed with the compression by a ligature. There are three hypotheses on the mechanism of the obstruction of vertebral arteries: They are due to (1) the compression on the posterior and inferior region of the mastoid processes ("posterior compression"), (2) the backward and upward compression at the same time on the thyrohyoid membrane ("anterior compression") and (3) the vertical traction on the neck ("indirect obstruction"). In atypical hanging, carotid arteries can be indirectly closed in certain head positions. Vertebral arteries are not closed by the horizontal compression (hanging in a prone position). The "posterior compression" is effective. The "indirect obstruction" seems to be in existence. In the cases where ligatures do not run on the front of the necks but on the faces, it is advisable to consult the figures prepared by Rauschke (1957) and Brinkmann et al. (1981).(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Obstruction↗

PubMed1991

[Paternity test with single locus DNA probes].

Seven kinds of DNA probes recognizing hypervariable DNA loci were applied to 28 cases of paternity test, involving two cases in which the putative fathers had died. The combinations of probe and restriction enzyme are as follows; MR24/1-HinfI, 3'Globin-PvuII, Ha-ras-PvuII, Mucin-PvuII, D2S44 (pYNH24)-MspI, D17S30 (pYNZ22)-MspI, D1S57 (pYNZ2)-RsaI. The reported number of the alleles are 37, 39, 5, 10, 33, 15, and 5, respectively. Those probes lie on different chromosomes except D1S57 on 1p and Mucin on 1q21. Exclusion probability (EP) and paternity index (PI) were calculated from the allele frequencies in Japanese population reported by Yokoi et al. Cumulative EP from 7 DNA probes was 0.999932, and cumulative PI ranged from 7.3 X 10(6) to 947. Also, cumulative EP from 17 kinds of conventional blood group markers (CBGM) was 0.9776, and cumulative PI ranged from 1290 to 0.11. Total EP from 7 DNA probes and CBGM was 0.999998478. Cumulative PI from 7 DNA probes were 5 to 2,000,000 times higher than that from CBGM. The single locus hypervariable DNA polymorphisms are considered to be informative for paternity test.

DNA Probes↗

PubMed1990

Immunohistochemical localization and dynamics of paraquat in small intestine, liver and kidney.

Immunohistochemical techniques were used to observe the localization of paraquat in the small intestine, liver and kidney, organs that absorb and eliminate chemicals. Paraquat-poisoned rats were killed 3 h, 12 h, 24 h, 3 days, 7 days and 10 days after intravenous administration of paraquat. Three hours after injection, paraquat was localized in hepatocytes and in the kidney in the epithelial cells of the distal tubule. The amount of paraquat in the liver and kidney increased by 24 h after the administration and thereafter decreased with time, suggesting that paraquat is secreted into bile and urine. In the intestine, 3 h after injection, paraquat was localized in the epithelial cells. The same finding was also made in rats with a cannulated bile duct. Therefore, it is likely that paraquat is secreted into the gut lumen from epithelial cells and that paraquat secreted from liver into the duodenum is reabsorbed into the epithelial cells of the intestine.

Animals↗

PubMed1990

Lewis typing of human saliva stains by enzyme-linked immunosorbent assay (ELISA) using monoclonal anti-Le(a) and anti-Le(b) antibodies.

The Lewis blood grouping of human saliva stains could be detected by an enzyme-linked immunosorbent assay (ELISA) using anti-Le(a) and anti-Le(b) monoclonal antibodies with an avidin-biotin complex (ABC). The saliva stains (1.0 by 1.0 cm in size) were used as samples and not only could the Lewis substances of 57 individual stains be correctly typed by this method, but also it was clarified that there are several different secretion patterns of amounts of Le(a) and Le(b) substances in 3 individual Lewis types.

Antibodies, Monoclonal↗

PubMed1990

Serum aldolase isozyme levels in patients with cerebrovascular diseases.

A subunit specific radioimmunoassay was developed for the quantification of human aldolase A, B, and C. The method used was a double antibody radioimmunoassay using radioiodinated purified aldolase A, B, or C subunits as the ligand, specific chicken antibodies to aldolase isozymes and rabbit antibodies to chicken IgG. The Iodogen method was used for iodination of the purified isozyme subunits in this study. Human brain tissue contained similar concentrations of aldolase A and aldolase C, and a smaller amount of aldolase B, which was the main isozyme of liver tissue. Levels of serum aldolase A were greater than 203 ng/ml, the upper limit of normal, in six of 24 patients with cerebral infarction and in 11 of 31 patients with cerebral hemorrhage. Nine of 24 patients with cerebral infarction and 16 of 31 patients with cerebral hemorrhage had serum aldolase C levels greater than 4.1 ng/ml, the upper limit in normal sera. These data suggest that serum aldolase C may be a more specific and sensitive marker of cerebrovascular diseases than aldolase A. We also demonstrated that serial measurement of serum aldolase C in patients with cerebrovascular diseases might be useful in estimating prognosis, since serially increasing serum aldolase C levels during the course of these diseases were correlated with a high mortality rate.

Adult↗

PubMed1990

Estimating stature from the length of the lumbar part of the spine in Japanese.

In order to estimate the stature from the length of the lumbar part of spine (LLPS), studies were made on Japanese males (n = 42) and females (n = 29) autopsied in our laboratory during 1984-1987. Somatometry was performed on the stature and LLPS in centimetres, the latter being measured from the upper edge of the first lumbar vertebral body, to the promonitorium, along the anterior surface of the spine. LLPS were 19.9 +/- 1.19 cm in males and 18.6 +/- 0.84 cm in females (mean +/- S.D.). The regression equations calculated were as follows: stature in males = LLPS x 3.23 + 101.7; stature in females = LLPS x 2.31 + 110.8. The standard errors of estimate were 6.16 cm in males and 4.05 cm in females. This method is useful for estimating the stature of severely burned or mutilated bodies which have no limbs.

Adolescent↗

PubMed1990

[An autopsy case of atypical hanging: were arteries and air passage obstructed?].

A housewife hanged herself with her left foot on a washstand and her right foot above the floor. The ligature mark encircled once horizontally at the height of the laryngeal prominence (horizontal part), crossed at the front of the neck, rose to the posterior regions of the mandibular angles and extended upward to the preauricular regions (ascending part). Petechial haemorrhage was in the conjunctivae and froth was in the air passage. Vertebral arteries are not obstructed by the compression of the horizontal part (Brinkmann et al., 1981). Vertebral arteries are possibly not obstructed by the traction of the ascending part (experiment on our own necks). An air passage is not obstructed by the compression of the horizontal part (Langreuter, 1886; Strassmann, 1922). Obstruction of an air passage by typical hanging is removed by putting the bent head to upright position (Langreuter, 1886). From these experimental observations we clarified that in our case the vertebral arteries and air passage had very possibly not been obstructed by the hanging while 70-80% of her body weight, i.e. 40-45 kg, had loaded on the neck. The force to obstruct the arteries and air passage by hanging, which has been quoted in texts and articles in Japan, is absolutely due to the value for "typical" hanging.

Adult↗