Biomedical subjects

T Takatori

Publications and source records attributed to T Takatori.

At least 55 records · Page 3Linked to original sources

PubMed1996

Reconsideration of the sequence of rigor mortis through postmortem changes in adenosine nucleotides and lactic acid in different rat muscles.

We examined the changes in adenosine triphosphate (ATP), lactic acid, adenosine diphosphate (ADP) and adenosine monophosphate (AMP) in five different rat muscles after death. Rigor mortis has been thought to occur simultaneously in dead muscles and hence to start in small muscles sooner than in large muscles. In this study we found that the rate of decrease in ATP was significantly different in each muscle. The greatest drop in ATP was observed in the masseter muscle. These findings contradict the conventional theory of rigor mortis. Similarly, the rates of change in ADP and lactic acid, which are thought to be related to the consumption or production of ATP, were different in each muscle. However, the rate of change of AMP was the same in each muscle.

Adenine Nucleotides↗

PubMed1996

Production of hydroxy fatty acid (10-hydroxy-12(Z)-octadecenoic acid) by Lactobacillus plantarum from linoleic acid and its cardiac effects to guinea pig papillary muscles.

Lactobacillus plantarum produced 10-hydroxy-12(Z)-octadecenoic acid (10-OHODA) from linoleic acid. It was suspected that 10-OHODA might be closely related to leukotoxin (9,10-epoxy-12-octa-decenoic acid (LTx)) which was regarded as a toxic and/or defensive substance in living beings. The cardiac effect of 10-OHODA, which was biosynthesized by Lactobacillus plantarum, on an isolated guinea-pig papillary muscle was determined. Its effect on the contractile force of the tissue preparations was examined both in terms of its concentration and the time of exposure. A decrease in muscular tension was observed immediately after administration of 10-OHODA at concentrations of 30, 100, and 300 microM. We also compared the effect of 10-OHODA on muscle tension with that of LTx and its isomer 12,13-epoxy-9-octadecenoic acid (LTx'). Each inhibitory effect on the contractile force of the papillary muscle was statistically significant in the concentration of 300 microM 5 min after administration compared to the control in the absence of each fatty acid, suggesting that 10-OHODA is likely to exert some influence on the circulatory system together with LTx and LTx'.

Animals↗

PubMed1996

Investigations on the mechanism of adipocere formation and its relation to other biochemical reactions.

In the adipocere, which is one of the postmortem changes, some specific fatty acids possessing higher melting points, together with soap, play an important role in the formation of adipocere. These fatty acids were shown to be mainly 10-hydroxystearic and 10-hydroxypalmitic acids. Moreover, slight amounts of 10-oxostearic and 10-oxopalmitic acids, which have higher melting points than those of hydroxy fatty acids, exist in the adipocere as well. The substantial adipocere is formed and stabilized by these specific fatty acids together with the soap. The hydroxy fatty acid (OHFA) and oxo fatty acid (OXOFA) are biosynthesized by some bacterial enzymes. Various aerobic and anaerobic bacteria are involved in the formation of adipocere. For example, microbial conversion of various unsaturated fatty acids to 10-OHFA by Micrococcus luteus was investigated. It turned out that 10-OHFA was synthesized only from fatty acids possessing cis-9-unsaturation. It was also shown that 10-OHFAs were converted to the corresponding 10-OXOFAs but the 10-OXO compounds were inactive as substrates. Furthermore, it was found that the enzyme preparations from Flavobacterium meningosepticum solubilized by sonication catalyzed not only hydration of oleic acid to produce 10-hydroxystearic acid, but also dehydrogenation of this product in the presence of deuterium. On the other hand, we found out that there was 10-hydroxy-12-octadecenoic acid (10-OHODA) from linoleic acid in some kinds of adipocere. Recently, 10-epoxy-12-octadecenoic acid (leukotoxin, LTx), which is one of the lipid peroxides, was found not only in rice plants but in polymorphonuclear leukocytes. Since LTx was found in leukocytes related to inflammatory response, interest has been focused on its involvement, not only in the basic mechanism of biological defense, but also on the mechanism of shock as a vasoactive substance. A postmortem change itself is only remotely associated with a phenomenon in a living body. However, 10-OHODA found in adipocere seemed to exist also in polymorphonuclear leukocytes, suggesting that this compound might be closely related to a biological reaction.

Adipose Tissue↗

PubMed1996

Monoepoxide production from linoleic acid by cytochrome c in the presence of cardiolipin.

We found that cytochrome c (Cyt c) could oxidize cardiolipin (CL), and detected monoepoxides of linoleic acid (LA) in the fatty acids constituting the oxidized CL. We also found that in the presence of CL and Cyt c, free LA was oxidized and LA monoepoxides were produced. The aim of this study was to elucidate the mechanism of this lipid peroxidation. We concluded that ferric Cyt c produced some radical species from water-soluble oxygen in the presence of CL (CL-Cyt c system) and that radicals oxidized free LA or CL. The CL-Cyt c system may be another LA monoepoxide producing system in the neutrophil and may account for the lipid peroxidation observed in the ischemia-reperfusion-induced cardiac injury.

Cardiolipins↗

PubMed1996

Superoxide anion reduces the ability of myeloperoxidase to damage lipids.

The aim of this study was to determine whether lipids are damaged by myeloperoxidase (MP) not only with hydrogen peroxide (H2O2), but also with a H2O2-generating system. Using the hypoxanthine-xanthine oxidase-Cu,Zn-superoxide dismutase (HX-XO-SOD) system as an effective H2O2-generating system, we observed a reduction in the ability of MP to produce peroxylipids in the HX-XO-SOD-MP system, compared with the H2O2-MP system. We also noted that MP inhibited the production of monoepoxide by the H2O2-cytochrome c (Cyt c) system. These results suggest that MP plays a role as an absorber of active oxygen species and prevents phagocytes from self-destruction.

Cytochrome c Group↗

PubMed1995

Establishment of a monoepoxide (leukotoxin and its isomer) producing system using a hydrogen peroxide-generating system.

We established an effective monoepoxide-generating system by combining cytochrome-c (Cyt-c) with a hydrogen peroxide (H2O2)-generating system comprising hypoxanthine (HX), xanthine oxidase (XO) and superoxide dismutase (SOD; HX-XO-SOD-Cyt-c system). Using this and the H2O2-Cyt-c system, we proved that monoepoxide production from linoleic acid was due to hydroxy radical formation by the reaction of Cyt-c with H2O2 and not to the formation of other active oxygen species.

Benzoates↗

PubMed1995

pH dependent alterations of monoepoxides and monochlorohydrins of linoleic acid, and their existence in vivo.

Some monoepoxides of linoleic acid (LA) were converted to monochlorohydrins in low-pH solutions containing chloride ions (Cl-). Conversely, monochlorohydrins of LA were converted to monoepoxides in high-pH solutions. We attempted to determine whether these monochlorohydrins and monoepoxides were produced from LA by the cytochrome-c-H2O2-and/or myeloperoxidase-H2O2-system. The existence of monoepoxides and monochlorohydrins of LA in leukocytes was confirmed by high-performance liquid chromatography (HPLC). Furthermore, leukotoxin in human leukemia cells (THP-1) was stained immunohistochemically by a monoclonal anti-leukotoxin antibody.

Animals↗

PubMed1995

Delivery and cytotoxicity of RS-1541 in St-4 human gastric cancer cells in vitro by the low-density-lipoprotein pathway.

RS-1541 is a 13-O-palmitoyl derivative of rhizoxin, an inhibitor of tubulin polymerization. RS-1541 has been shown to bind preferentially to plasma lipoproteins and to exhibit selective and sustained uptake by tumors in mice. To elucidate a mechanism of RS-1541 cytotoxicity, the cellular uptake and the cytotoxicity of a complex of RS-1541 with human low-density lipoprotein (RS-1541/LDL complex) were investigated in cultured St-4 human gastric cancer cells. Both the cellular uptake and the cytotoxicity of the RS-1541/LDL complex were greater in cells with higher LDL-receptor activities than in control cells. Excess amounts of LDL or 1 microM of monensin, a proton ionophore, significantly inhibited both the uptake and the cytotoxicity of the complex. Chloroquine, an inhibitor of lysosomal enzymes, decreased the intracellular level of rhizoxin liberated from RS-1541 and suppressed the cytotoxicity of the RS-1541/LDL complex. However, a detergent-aided solution of RS-1541 showed very low cellular uptake and cytotoxicity, irrespective of the LDL-receptor activities of these cells. These results demonstrate that the RS-1541/LDL complex is incorporated into the cells via the LDL receptor and that it manifests its cytotoxic activity after forming rhizoxin, the original antitumor agent, in the lysosomes.

Antibiotics, Antineoplastic↗

PubMed1995

Intracellular activation and cytotoxic action of RS-1541 against cultured human tumor cells.

RS-1541, an acyl-derivative of rhizoxin (Fig. 1), is a potent antitumor compound. This agent showed cytotoxicity in vitro on some cultured human tumor cells, although it was less potent than rhizoxin. Rhizoxin exhibited antitumor effects by inhibiting the polymerization of tubulin, whereas RS-1541 did not inhibit tubulin polymerization in vitro. However, cell cycle analysis in vivo showed that the two agents had the same mode of action. The cytotoxicity of RS-1541 was enhanced when the initial cell density of the cells was increased. The cytotoxicity was also enhanced when the membrane fraction of St-4 cells, which were the most sensitive to RS-1541 among the cell lines tested, was added to the target cells. When St-4 cells were incubated with [14C]-RS-1541, significant amounts of [14C]-rhizoxin were produced within the cells. Further fractionation of the crude membrane showed that the activity that enhanced the cytotoxicity of RS-1541 (RS-1541-enhancing activity) belonged to the mitochondrial-lysosomal fraction, not to the microsomal fraction. Both the enhancing activity and the activity that converting [14C]-RS-1541 to [14C]-rhizoxin (RS-1541-converting activity) were inhibited by treatment with chloroquine, an inhibitor of lysosomal function. Cholesterol esterase derived from Candida cylindracea had RS-1541-enhancing and -converting activities. These data suggest that RS-1541 exerts its cytotoxic action after being converted to rhizoxin within the cells by a lysosomal enzyme such as cholesterol esterase.

Antibiotics, Antineoplastic↗

PubMed1995

Immunohistochemical dynamics of leukotoxin (9,10-epoxy-12-octadecenoic acid) in lungs of rats.

This paper investigates the immunohistochemical dynamics of leukotoxin (9,10-epoxy-12-octadecenoic acid, LTx) in the lungs of rats exposed to hyperoxia with or without paraquat. The rats were treated with 100% oxygen or ambient air for 24, 48, 72 and 96 h in the presence or absence of a low or high dose paraquat (1,1'-dimethyl-4,4'-bipyridinium, PQ) injection. Immunostaining for LTx demonstrated positive reactions in the neutrophils that showed a progressive increase in intensity of staining with time in all groups exposed to 100% oxygen and in the group with high dose PQ, but the positive findings were weak in the group injected with low dose PQ only. We found the positive immunostaining reaction not only in neutrophils but also in alveolar macrophages. This indicates that LTx is produced by alveolar macrophages as well as by neutrophils depending on the treatment period under hyperoxic conditions, suggesting that LTx is an important chemical mediator in pulmonary diseases.

Animals↗

PubMed1995

Analysis of pedestrian injuries in traffic accidents (2)--Especially on leg injury.

A deep case study on 118 pedestrians struck to fronts of vehicles or vehicle derivatives was carried out. In this paper we investigated a leg injury which occurs the most frequently in a vehicle-pedestrian collision. The data obtained from the case study were compared with those of autopsied cases. Influence of impact speed and point, and of an accident pattern were considered. The leg injury showed higher AIS (Abbreviated Injury Scale) than that of the arm injury caused by direct impact against the front exterior of vehicles. The impact speed and ISS (Injury Severity Score) showed strong correlation, but the former and AIS did not show significant correlation. The higher impact speed and the run-over are likely to cause a bilateral leg fracture.

Abbreviated Injury Scale↗

PubMed1995

[Age estimation by appearance of gray hair in pubic hair].

The pubic hair of Japanese males aged 12-90 years old (n = 123) and females 14-85 ys. (n = 80) autopsied during 1984-1993 was investigated to determine its appearance age and possible appearance age of gray hair. As the appearance degree of gray hair in pubic hair 5 stages were applied to samples to establish a criterion for age estimation. Stage 0; no gray hair, 1; 1-3 gray hairs, 2; a few-10, 3; 10 gray hairs-2/3 of the entire pubic hair, 4; more than 3/4. The appearance age of gray hair with appearance rate 100% (75%) was more than 65 (55) ys. in both sex. The possible appearance age was more than 30 ys. in males and 36 ys. in females, practically younger than "45 years old" which had been described in texts. The age range with a hit rate 100% is at stage 0; less than 62 ys. in males, less than 59 ys. in females, at stage 1; 30-64 ys. in males, 36-60 ys. in females, at stage 2; 43-72 ys., 39-85 ys. and at stage 3; 49-77 ys,--.

Adolescent↗

PubMed1994

Production of monoclonal antibody reactive with leukotoxin and its immunohistochemical application.

A sensitive enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody (ALM-1) was developed for the determination of leukotoxin (9,10-epoxy-12- octadecenoic acid), which was reported to exist in human burned skin and neutrophils, and was regarded as a toxic and/or defensive substance in living beings. The leukotoxin was conjugated with bovine serum albumin (BSA) by means of the mixed anhydride technique as immunogen, and BALB/c mice were immunized over 6 months. The detection limit of leukotoxin was at least as low as 5 ng in this ELISA. This antibody had a strong specificity to leukotoxin and no cross-reactivity with the other analogs tested, and was usable for an immunohistochemical application. By using the antibody, leukotoxin was immunohistochemically observed not only in neutrophils, but also in alveolar macrophages in an oxygen-exposured rat lung.

Animals↗

PubMed1994

Estimation of time of death by quantification of melatonin in corpses.

A method for the estimation of time of death (TOD), was evaluated by measuring the melatonin (MT) content of pineal bodies (PBs), sera and urine samples from 85 cadavers. A total of 44 cadavers were investigated in Sapporo (geographical coordinates N 43 degrees 4', E 141 degrees 21') and 41 in Tokyo (N 35 degrees 39', E 139 degrees 44'). MT contents were measured by radioimmunoassay (RIA) in 75 PBs, 27 sera and 14 urine samples. Exponential differences of pineal MT content were recognized between peaks in nighttime and nadirs in daytime, ranging from 0.099 to 63.2 ng/PB. Circadian rhythms were also observed for the concentrations of MT in serum (11-205 pg/ml), and in urine (7.5-137.5 pg/ml). Consequently, criteria for the TOD estimation are proposed as follows. 1) Pineal MT contents--(1) 0-0.2 ng/PB: TOD 1100-1700 hours, (2) 0.2-0.3 ng/PB: TOD 0700-2000 hours, (3) 0.3-1 ng/PB: inconclusive, (4) 1-4 ng/PB: TOD 1600-1000 hours, (5) 4-8 ng/PB: TOD 2000-0800 hours, (6) over 8 ng/PB: TOD 2000-0500 hours, 2) Serum MT concentration--(1) 0-100 pg/ml: inconclusive, (2) over 100 pg/ml: TOD 2200-0100 hours, and 3) Urinary MT concentration--(1) 0-35 pg/ml: inconclusive, (2) over 35 pg/ml: TOD 1800-0600 hours. The range of the estimation can be limited by a combination of these 3 criteria. The present method can be combined with other methods for estimating the TOD to decrease the range.

Adolescent↗

PubMed1994

[The difficulties in communication through RS-232C interface between monitor devices and a personal computer--the difference of data output format and transmit mode].

We investigated data output format and transmit mode of communication through RS-232C interface between monitor devices and a personal computer. The baud rate, start bit, data bits, parity bit and stop bits are listed with transmit mode of six companies' monitor devices which are now widely sold in Japan. Each monitor device has its own data output format and transmit mode, which are quite different from the others and make it somewhat difficult to import data from different monitor devices to a personal computer. We suggest that, because two or three different monitor devices are commonly used during anesthesia, some general standard should be established to make an easy communication between monitor devices and a personal computer for ordinary users.

Anesthesia↗

PubMed1994

[An autopsy case of Smith-Lemli-Opitz syndrome].

A 17 month-old girl was found dead in her bed. The findings of a juditial autopsy revealed that she had a cleft palate, low-set and accessory ears, and syndactyly of right and left second and third toes and right third and fourth toes. Her birth size was small and subsequently she failed to thrive. Organ anomaly, such as atriaol septal defect, accessory spleens, and uterus bicornis bicollis were found. From these findings, this case was diagnosed as a Smith-Lemli-Opitz syndrome.

Abnormalities, Multiple↗

PubMed1994

Intercellular localization of leukotoxin (9:10-epoxy-12-octadecenoic acid) in lungs in rats by an immunoelectron microscopy.

In this paper intercellular localization of leukotoxin (9:10-epoxy-12-octadecenoic acid, LTx) in neutrophils and alveolar macrophages of rats exposed to the 100% oxygen was demonstrated by a pre-embedding method of an immunoelectron microscopy. The Sprague-Dawley rats were treated with the 100% oxygen for 72 hrs, and the lungs were stained with anti-LTx IgG (Fab) by an immunocytochemical method and examined by a transmission electron microscope. The positive reactions with anti-LTx IgG (Fab) was shown strongly in the rough-surfaced endoplasmic reticulum (rER) and cell membranes of the neutrophils and alveolar macrophages. This result indicates that LTx is produced in biomembrane-rich organelle of alveolar macrophages as well as neutrophils dependently on the treatment period under hyperoxia conditions, suggesting that LTx is closely related to biological reactions and is an important chemical mediator on pulmonary diseases.

Animals↗

PubMed1994

Identification and dynamics of paraquat in the bone marrow, thymus and spleen in rats using immunohistochemical techniques.

We reported the immunohistochemical identification of paraquat in the immune and hematopoietic systems such as bone marrow, spleen and thymus. Twelve paraquat-poisoned rats were sacrificed in 3 h, 12 h, 3 days, 7 days and 10 days after intravenous administration of paraquat. In the bone marrow, paraquat was localized in several types of blood cells (granulocyte, erythrocyte and megakaryocyte) and their precursors between 24 h and 7 days after the injection. In the thymus, paraquat was mainly localized in the medulla between 12 h and 7 days after the injection, whereas in the spleen, it was mainly localized in the red pulp between 12 h and 10 days after administration of paraquat.

Animals↗