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Biomedical subjects

T Kondo

Publications and source records attributed to T Kondo.

At least 757 records · Page 42Linked to original sources
PubMed1995

Postmortem degradation of administered ethanol-d6 and production of endogenous ethanol: experimental studies using rats and rabbits.

Deuterium-labeled ethanol-d6 was employed to study the metabolism and postmortem change of ethanol in putrefied organ tissues. First, 4 ml/kg body weight of 25% (w/v) solution of ethanol-d6 was administered orally to each of 15 rats. The heart blood and organs were collected 15-90 min after the administration and the ethanol-d6 was analyzed by head space gas chromatography/mass spectrometry. The ethanol-d6 concentration in the organ tissues reached its maximum at 15 min after the administration and then gradually declined, showing the same pattern as human ethanol metabolism. Ethanol-d6 (3 ml of the same solution/kg body weight) was injected into the vein of a rabbit's ear (total of 12 rabbits). The rabbit was killed with carbon monoxide 30 min after the administration and the carcass was allowed to stand for 1-4 days at 30 degrees C in a moist chamber. The concentration of ethanol-d6 decreased moderately. Postmortem ethanol and 1-propanol concentrations, in contrast, showed marked increases 2.5 days and more after sacrifice in line with the degree of putrefaction of each organ tissue including skeletal muscle. This suggests the postmortem activation of micro-organism activity. These results indicate that ethanol concentrations in cadaver tissues must be carefully assessed with due consideration of postmortem degradation and production.

1-Propanol↗
PubMed1995

Sex determination by polymerase chain reaction on mummies discovered at Taklamakan desert in 1912.

Sex determination was performed by the polymerase chain reaction (PCR) on eight adult mummies and one child mummy which were discovered at Taklamakan desert in 1912 and now belong to the Lüshun Museum in China. Archaeologically, these mummies were humans living in the seventh century, that is, more than 1300 years ago. Putative sex determination was performed based on external morphology for six of the eight adults, but it was impossible for the other two adults and one child mummy due to marked destruction on the external morphology. Hair, muscle and skin samples were then collected from each adult mummy, and skin and rib samples from the child mummy. Forty PCR cycles were performed as follows: denaturation at 94 degrees C for 40 s, annealing at 55 degrees C for 30 s and extension at 72 degrees C for 1 min. The primer and PCR reaction mixture were prepared according to the report by Witt and Erickson (M. Witt and R. P. Erikson, A rapid method for detection of Y-chromosomal DNA from dried blood specimens by the polymerase chain reaction. Hum. Genet., 82 (1989) 271-274)). Two different pairs of primer were used. One was X1, X2 (X1: 5'-AATCATCAAATGGAGATTTG-3'; X2: 5'-GTTCAGCTCTGTGAGTGAAA-3') to flanking the 170 bp fragment of the alphoid repeats on the human X chromosome, and the other was Y11, Y22 (Y11: 5'-ATGATAGAAACGGAAATATG-3'; Y22: 5'-AGTAGAATGCAAAGGGCTC-3') to flanking the 130 bp fragment of the alphoid repeats on the human Y chromosome. Extracted DNA solutions from mummy samples was purified using a spin column (T. Yoshii, K. Tamura, T. Taniguchi, K. Akiyama and I. Ishiyama, Water-soluble eumelanin as a PCR-inhibitor and a simple method for its removal. Jpn. J. Legal Med., 47 (1993) 323-329 (in Japanese with English abstract) for removing PCR-inhibitors, and bovine serum albumin (BSA) was employed to inhibit the remaining impurities even after the purification with the column. In six adult cases where the putative sex was determined from external morphology, the sex in five cases was consistent with that by PCR using hair, muscle, and skin samples, but the other one was inconsistent. In two adult cases where sex estimation was externally impossible, the sex was determined to be male because both X-specific and Y-specific bands were clearly detected. The child mummy was definitely male. This study shows that the sex determination was possible by the PCR method even with very ancient human samples > 1300 years old, that spin column was useful for removing impurities in the DNA solution from ancient human samples and that the BSA of optimum concentration suppressed the action of the PCR-inhibitory factors.

Adult↗
PubMed1995

Differences in motor control in the bronchus and extrathoracic trachea.

The motor control of the bronchus and extrathoracic trachea was evaluated by continuously measuring bronchial diameter and tracheal muscle tension as well as phrenic nerve activity in decerebrated, paralyzed, artificially ventilated dogs. Spontaneous rhythmic changes in bronchial diameter and tracheal muscle tension occurred in phase with phrenic burst during mechanical ventilation and during apnea induced by disconnecting the ventilator. There was a small but consistent difference in the timing of their rhythmic activities; bronchial constriction started at mid-inspiration, whereas tracheal contraction began just prior to the end of inspiration. Both were active in the post-inspiratory phase. Both hypercapnia and apnea caused an enhanced rhythmic constriction of the bronchus, while evoking a tonic contraction of the trachea. Intermittent electric stimulation of the efferent vagus nerves revealed that repetitive stimulation with a short intermission was necessary to evoke a sustained constriction of the bronchus, and that the bronchus could maintain the sustained constriction only transiently. These results indicate that the motor control of the bronchus and extrathoracic trachea are distinct. The central nervous system may contribute to the difference in timing of the contraction between tracheal and bronchial smooth muscle. However, the difference in response to electric stimulation of the nervus vagus may be attributed to the peripheral neuromuscular system.

Animals↗
PubMed1995

Physiological basis of myocardial contrast enhancement in fast magnetic resonance images of 2-day-old reperfused canine infarcts.

BACKGROUND: Contrast-enhanced fast magnetic resonance (MR) images of acute, reperfused human infarcts demonstrate regions of hypoenhancement and hyperenhancement. The relations between the spatial extent and time course of these enhancement patterns to myocardial risk, infarct, and no-reflow regions have not been well characterized. METHODS AND RESULTS: The proximal left anterior descending coronary artery was occluded in 11 closed-chest dogs for 90 minutes followed by 2 days of reperfusion. Regional blood flow was determined by use of radioactive microspheres. The animals were studied at the 2-day time point with contrast-enhanced fast MRI (Signa 1.5 T, General Electric). Thioflavin-S was administered to demarcate no-reflow regions. The hearts were then excised, sectioned into five base-to-apex slices, stained with 2,3,5-triphenyltetrazolium chloride (TTC), and photographed under room light (for TTC) and ultraviolet light (for thioflavin). The spatial extents of thioflavin-negative, TTC-negative, and risk regions were compared planimetrically with MRI hypoenhanced and hyperenhanced regions. The spatial locations of subendocardial hypoenhancement in MR images correlated closely with those of thioflavin-negative regions. Microsphere blood flow in these regions was significantly reduced compared with remote regions (0.37 +/- 0.09 versus 0.88 +/- 0.10 mL/min per gram, respectively, P < .001) and with baseline (0.37 +/- 0.09 versus 0.87 +/- 0.15 mL/min per gram, P < .01). The spatial extent of hyperenhancement was smaller than the risk region (r = .64, slope = 0.48, P < .001) but highly correlated with TTC-negative regions and were, on average, 12% larger (r = .93, slope = 1.12, P = .035). CONCLUSIONS: In contrast-enhanced MR images of 2-day-old reperfused canine infarcts, myocardial regions of hypoenhancement are related to the no-reflow phenomenon. Approximately 90% of the myocardium within hyperenhanced regions is nonviable.

Animals↗
PubMed1995

Augmentation of transport for cisplatin-glutathione adduct in cisplatin-resistant cancer cells.

We studied the outward transport of cisplatin (CDDP)-glutathione (GSH) adduct (DDP-GSH) in CDDP-resistant cancer cells. Incubating the cells in the presence of CDDP resulted in the formation of an adduct with GSH and subsequent transport outside the cells. We used human colonic cancer cells sensitive (HCT8) and resistant (HCT8DDP) to CDDP and human ovarian cancer cells sensitive (A2780) and resistant (A2780DDP) to CDDP as materials. The concentration of intracellular GSH was higher in the resistant cells (118.7 +/- 5.9 nmol/10(6) HCT8DDP versus 19.0 +/- 1.0 nmol/10(6) HCT8 and 24.1 +/- 1.2 nmol/10(6) A2780DDP versus 9.4 +/- 0.5 nmol/10(6) A2780, respectively). The activity of the GSH-synthesizing enzyme, gamma-glutamylcysteine synthetase (gamma-GCS) was higher in the CDDP-resistant cells (7.1 +/- 0.2 milliunits/10(6) HCT8DDP versus 2.2 +/- 0.1 milliunits/10(6) HCT8 and 2.9 +/- 0.1 milliunits/10(6) A2780DDP versus 1.4 +/- 0.1 milliunits/10(6) A2780, respectively). Furthermore, immunological levels of gamma-GCS and the expression of gamma-GCS mRNA were higher in these CDDP-resistant cells than those in the control cells, in accordance with the change in the concentration of GSH. DDP-GSH transport increased in the CDDP-resistant colonic cancer cells by 219% (324 +/- 12 fmol/10(6) HCT8DDP cells/min versus 148 +/- 11 fmol/10(6) HCT8 cells/min) and the CDDP-resistant ovarian cancer cells by 126% (127 +/- 7 fmol/10(6) A2780DDP cells/min versus 101 +/- 8 fmol/10(6) A2780 cells/min). DDP-GSH transport was also estimated using inside-out vesicles from these cells. The active transport of DDP-GSH was 243% of HCT8 in HCT8DDP and 121% of A2780 in A2780DDP. These data suggest that the acquisition of CDDP resistance in cancer cells is due partly to the increase in the transport of DDP-GSH outside the cells as well as the increase in the concentration of GSH. Immunological estimation of the membrane proteins against human erythrocyte glutathione S-conjugate-stimulated Mg(2+)-ATPase sera resulted in no apparent cross-reactivity, suggesting that there are several transport systems for DDP-GSH.

Antineoplastic Agents↗
PubMed1995

Circadian oscillations of cytosolic and chloroplastic free calcium in plants.

Tobacco and Arabidopsis plants, expressing a transgene for the calcium-sensitive luminescent protein apoaequorin, revealed circadian oscillations in free cytosolic calcium that can be phase-shifted by light-dark signals. When apoaequorin was targeted to the chloroplast, circadian chloroplast calcium rhythms were likewise observed after transfer of the seedlings to constant darkness. Circadian oscillations in free calcium concentrations can be expected to control many calcium-dependent enzymes and processes accounting for circadian outputs. Regulation of calcium flux is therefore fundamental to the organization of circadian systems.

Aequorin↗
PubMed1995

Age-related changes in cellular localization and enzymatic activities of cathepsins B, L and D in the rat trigeminal ganglion neuron.

Altered localization and cellular level of three distinct lysosomal proteinases, cathepsins B (CB), L (CL), and D (CD), with aging were investigated in the rat trigeminal ganglion (TG) by immunohistochemical and quantitative analyses. At the light microscopic level, the intracytoplasmic distribution of these three enzymes was found to change with aging: These lysosomal proteinases in the TG of young rats (2-3 months of age) were widely and evenly distributed throughout the cytoplasm as coarse intracytoplasmic granules, whereas they were localized at focal cytoplasmic sites of the TG neurons of aged rats (28-31 months of age) as coarse aggregates. A similar distribution was observed with a major lysosomal membrane sialoglycoprotein having an apparent molecular mass of 107 kDa (LGP107). The cellular distribution of the three cathepsins as well as LGP107 in the TG neurons of aged rats corresponded well with that of autofluorescent lipofuscin. At the electron microscopic level, the age-related redistribution of these cathepsins in the TG neurons was found to be due to their great accumulation in autolysosomes localized at the focal perinuclear sites. The cellular levels of CB and CL determined by activity measurement in the TG of the young rats were 1.8 and 1.7 times as much as those of the aged rats respectively. In contrast, no significant difference was observed between the CD activities in the two age groups. These results strongly suggest that age related changes in localization and cellular level of CB, CL, and CD in TG neurons are closely linked with the increased formation of autolysosomes and lipofuscins, which is the most ubiquitous age-related cytological alteration.

Aging↗
PubMed1995

Thrombin induces GRO alpha/MGSA production in human umbilical vein endothelial cells.

Thrombin, besides being a potent coagulation factor, exerts influence on endothelial and leukocyte functions and may thus be involved in the regulation of inflammatory reactions. The present study investigated whether thrombin stimulates the production of growth-related cytokine/melanoma growth-stimulatory activity (GRO alpha/MGSA) in endothelial cells. Human umbilical vein endothelial cells (HUVEC) stimulated with thrombin were found to product GRO alpha/MGSA in a dose- and time-dependent manner. This action of thrombin was completely suppressed by preincubation with either hirudin or antithrombin-III (AT-III)-heparin. Interestingly, the thrombin receptor-activating peptide SFLLRN mimicked the action of thrombin. In addition, staurosporine, a protein kinase C (PKC) inhibitor, attenuated the production of GRO alpha/MGSA by thrombin, SFLLRN and phorbol 12-myristate 13-acetate (PMA), but left the action of interleukin-1 beta (IL-1 beta) unchanged. These results suggest that catalytic activation of thrombin receptor by thrombin results in GRO alpha/MGSA production, at least in part, via a pathway involving PKC in HUVEC.

Alkaloids↗
PubMed1995

Transforming growth factor-beta 1 levels are elevated in the striatum and in ventricular cerebrospinal fluid in Parkinson's disease.

Transforming growth factor (TGF)-beta 1 content was measured for the first time in the brain (caudate nucleus, putamen, and cerebral cortex) and in ventricular cerebrospinal fluid (VCSF) from control and parkinsonian patients by a sandwich enzyme immunoassay. The concentrations of TGF-beta 1 were significantly higher in the dopaminergic striatal regions in parkinsonian patients than those in controls, but were not significantly different in the cerebral cortex between parkinsonian and control patients. Furthermore, the concentrations of TGF-beta 1 in VCSF were significantly higher in parkinsonian patients than those in non-parkinsonian control patients. Since TGF-beta 1 has potent regulatory activity on cell growth, these results suggest that TGF-beta 1 may have some significant modulatory role in the process of neurodegeneration in Parkinson's disease.

Aged↗
PubMed1995

Chronic transection of post-ganglionic parasympathetic and nasociliary nerves does not affect local cerebral blood flow in the rat.

The role of post-ganglionic parasympathetic nerve fibers from the sphenopalatine ganglion and nasociliary nerve fibers from the trigeminal ganglion in the regulation of basal cerebral blood flow (CBF) was examined using rats, which had been divided into three groups; a sham group, a denervation group and a denervation+NG-monomethyl-L-arginine (L-NMMA) group. In the denervation and denervation+L-NMMA groups, unilateral chronic transection of the above nerve fibers had been performed at the ethmoidal foramen (EF) for 2 weeks. In the sham group, the above nerve fibers were only exposed at EF and not severed 2 weeks before the CBF measurement. Local CBF was measured by the [14C]iodoantipyrine autoradiographic method after intravenous administration of saline in the sham and denervation groups or L-NMMA (30 mg/kg) in the denervation+L-NMMA group. No significant difference in CBF was noted on each side in any of the regions between the sham and denervation groups. L-NMMA induced a significant reduction in local CBF on either side in each brain region. Neither the animals which were administered saline nor those with L-NMMA showed any side-to-side differences in local CBF in any of the brain regions examined. These findings suggest that the perivascular nerve fibers running through the EF, which are known to contain substantial nitric oxide synthase (NOS), may not play a pivotal role in the regulation of basal CBF. The reduction in CBF induced by the acute administration of L-NMMA was not affected by the chronic denervation of the above NOS-containing perivascular nerves.

Animals↗
PubMed1995

Circadian orchestration of gene expression in cyanobacteria.

We wanted to identify genes that are controlled by the circadian clock in the prokaryotic cyanobacterium Synechococcus sp. strain PCC 7942. To use luciferase as a reporter to monitor gene expression, bacterial luciferase genes (luxAB) were inserted randomly into the Synechococcus genome by conjugation with Escherichia coli and subsequent homologous recombination. The resulting transformed clones were then screened for bioluminescence using a new developed cooled-CCD camera system. We screened approximately 30,000 transformed Synechococcus colonies and recovered approximately 800 clones whose bioluminescence was bright enough to be easily monitored by the screening apparatus. Unexpectedly, the bioluminescence expression patterns of almost all of these 800 colonies clearly manifested circadian rhythmicity. These rhythms exhibited a range of waveforms and amplitudes, and they also showed a variety of phase relationships. We also found bioluminescence rhythms expressed by cyanobacterial colonies in which the luciferase gene set was coupled to the promoters of several known genes. Together, these results indicate that control of gene expression by circadian clocks may be more widespread than expected thus far. Moreover, our results show that screening organisms in which promoterless luciferase genes have been inserted randomly throughout the genome by homologous recombination provides an extremely sensitive method to explore differential gene expression.

Circadian Rhythm↗
PubMed1995

A new surgical method from the viewpoint of personal identification: a case of identification based on the presence of a metallic Z-stent.

To the best of our knowledge, the first case of successful personal identification based on the characteristic finding of a metallic Z-stent, unexpectedly discovered in the common bile duct, is reported. An unknown human male cadaver was found at the seaside. The age was estimated to be approximately 50-70 years and the postmortem interval was considered to be approximately 2 weeks. There was a small surgical scar of 1.5 cm in diameter in the epigastrium. The cadaver was group A in the ABO blood group system. Internally, the following severe injuries were observed: the dislocation of the occipito-atlantal joint, fractures of the cervical and thoracic portions of the spinal column, multiple fractures of the bilateral ribs, and ruptures of the spleen, left kidney and liver. Furthermore, a 4.5 cm long metallic stent was found in the common bile duct, and the gallbladder was not thoroughly identified because of the severely tight adhesion of the surrounding tissues. In every cut surface of the liver, multiple bile plaques, signifying the presence of long-standing cholestasis, were conspicuous. A microscopic examination revealed the invasion of cancer cells into the liver, which was diagnosed as well or moderately differentiated adenocarcinoma, although the primary origin of the adenocarcinoma could not be determined. The cause of his death was diagnosed as traumatic shock. According to the police investigation after the autopsy, it was revealed that a 60-year-old male, suffering from gallbladder carcinoma, had disappeared.(ABSTRACT TRUNCATED AT 250 WORDS)

Common Bile Duct↗
PubMed1995

Enantioselective determination of pazinaclone, a new isoindoline anxiolytic, and its active metabolite in rat plasma by high-performance liquid chromatography.

A sensitive and specific high-performance liquid chromatographic method has been developed for the simultaneous determination of the enantiomers of pazinaclone (DN-2327), a new anxiolytic agent, and those of its active metabolite, M-II, in rat plasma. Organic solvent extraction of pazinaclone, M-II, and internal standard (I.S.) in plasma was followed by separation of the analytes from other metabolites using an achiral reversed-phase column. Fluorescence detection was employed with excitation and emission wavelengths of 328 and 367 nm, respectively. Separation of all the enantiomers and I.S. was then accomplished with normal- and chiral-phase columns connected in series. For each analyte, the lower quantitation limit was 0.5 ng/ml. The assay has been applied to a chiral inversion study in rats. Chiral conversion from one enantiomer of pazinaclone to the other hardly occurred. This method is suitable for enantioselective pharmacokinetic and toxicokinetic studies in animals.

Animals↗
PubMed1995

Enantioselective pharmacokinetics in animals of pazinaclone, a new isoindoline anxiolytic, and its active metabolite.

The enantioselective pharmacokinetics of a new anxiolytic, pazinaclone (DN-2327), and its active metabolite, M-II, were studied in animals. In rats and dogs given racemic pazinaclone intravenously, the total clearance and volume of distribution of (S)-pazinaclone were lower than those of (R)-pazinaclone, whereas the opposite results were obtained in monkeys. The differences in disposition were consistent with enantioselective protein binding, where the unbound fraction was greater for (R)-pazinaclone than that for the (S)-enantiomer in rats and dogs; the reverse was noted in monkeys. Lower clearance and distribution for (S)-pazinaclone in rats and dogs, and for the (R)-enantiomer in monkeys, resulted in comparable plasma profiles for the pazinaclone enantiomers and thereby those of the corresponding enantiomers of M-II. The unbound clearance (CLu) of (S)-pazinaclone was, however, greater than that of the antipode in rats and dogs and the CLu of each enantiomer was similar in monkeys. Thus, enantioselectivity in the kinetics of (S)- and (R)-pazinaclone appears to reside largely in plasma binding differences and is unrelated to variations in intrinsic clearance. The first-pass metabolism of (S)- and (R)-pazinaclone on oral administration of the racemate was enantioselective, with respective bioavailabilities of 1.7 and 0.8% in rats, 10.4 and 1.9% in dogs, and 0 and 11.4% in monkeys. Therefore, the enantioselectivity was more pronounced after oral dosing.

Absorption↗
PubMed1995

Two-dimensional electrophoretic analysis of down-regulated proteins in human fibroblasts immortalized by treatment with either 4-nitroquinoline 1-oxide or 60Co gamma rays.

Cellular proteins were examined by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) in order to determine the mechanisms of cellular aging and immortalization of human fibroblasts. A total of 10 cell lines were studied, four of which were immortalized. OUMS-24F and SUSM-1 cells were immortalized by repeated treatment with 4-nitroquinoline 1-oxide (4NQO), KMST-6 cells were immortalized by intermittent exposure to 60Co-gamma rays, and IMR-90/SV40 cells were immortalized with simian virus 40 (SV40). None of these immortalized cells were tumorigenic. Four normal human fibroblast cell lines, OUMS-24, AD 387, KMS-6 and IMR-90, and two human cervical cancer cell lines, HeLa and A-431, were also studied. Applying 2-D PAGE, the down-regulation of the identical proteins was observed in the four immortalized cell lines and in the two human cancer cell lines. Their molecular masses were about 80 kDa and the isoelectric points ranged between 5.5 and 6.3. We could not find any information on our proteins from the recent protein data bases. Further characterization of the proteins indicated that they might be phosphorylated cytoskeletal proteins.

4-Nitroquinoline-1-oxide↗
PubMed1995

Modification of rectal absorption of morphine from hollow-type suppositories with a combination of alpha-cyclodextrin and viscosity-enhancing polysaccharide.

An attempt was made to optimize the rectal delivery of morphine, using cyclodextrins as an absorption enhancer and polysaccharides as a swelling hydrogel in Witepsol H-15 hollow-type suppositories, and this was tested in rabbits. alpha- and beta-cyclodextrins enhanced the rate and extent of bioavailability, the former being more effective; gamma-cyclodextrin decreased the absorption of morphine. The in-vitro membrane permeation studies using excised rectal sacs revealed that alpha-cyclodextrin enhanced the permeation of morphine through the rectal membranes. In contrast, viscous polysaccharides such as xanthan gum retarded the plasma morphine levels after the rectal administration, reflecting in-vitro slow release characteristics. A combination of alpha-cyclodextrin and xanthan gum produced sustained plasma profiles of morphine along with an increased rectal bioavailability (more than 4 times). From the observation of the distribution behavior of suppositories in rabbit rectum and colon after the rectal administration, xanthan gum was found to prevent the upward spread of the drug. Gross and microscopic observations suggested that this preparation was less irritating to the rectal mucosa.

Animals↗
PubMed1995

Dreaming in the late morning: summation of REM and diurnal cortical activation.

Since the discovery that the characteristics of dreaming sleep are far stronger in Stage 1 rapid eye movement (REM) sleep than in any other biological state, investigators have attempted to determine the relative responsibility of the tonic versus the phasic properties of REM sleep for the different characteristics of dreaming--features such as the amount of information in the dream report, the brightness and clarity of the visual images, shifts in thematic continuity, and incongruities of image and meaning. The present experiment is designed to identify dream characteristics that are specifically associated with tonic changes in level of cortical activation within sleep. It samples reports of imagery and thought during spontaneous variations within one phase of the 24-h diurnal rhythm and across the REM-NREM (non-REM) sleep cycle in order to identify the independent and joint contributions of the two cycles to imagery and thought. The rising phase of the diurnal cycle in the late night and morning was estimated from clock time during the late night and early morning and was varied by delaying the sleep onset and waking time of the subjects. Considered together with other studies, the results suggest that the major determinant of vivid visual imagery and enhanced cognitive activity during sleep is a pattern of subcortical and cortical activation that is common to both the REM phase of the REM-NREM cycle and the activated phase of the 24-h diurnal wake-sleep cycle.

Adult↗