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Biomedical subjects

T Kikuchi

Publications and source records attributed to T Kikuchi.

At least 613 records · Page 34Linked to original sources
PubMed1987

[A macroscopical observation of the nerves to the pelvic floor muscles, the obturator internus and the quadratus femoris in some mammals].

Using dogs, cats, rabbits, guinea pigs and rats, the nerves to the Levator ani, the Coccygeus, the Obturator internus and the Quadratus femoris are observed and compared macroscopically. The main findings obtained are summarized as follows: The nerve to the Levator ani of dogs is one (95.0%) or two (5.0%) in number and arises most frequently from S2 and S3. That of rats is one in number and arises most frequently from S minus 1 (S-1) and S1. The nerve to the Coccygeus of dogs is one (70.0%) or two (30.0%) in number and arises most frequently from S2 and S3. That of rabbits is one (65.9%), two (24.4%) or three (9.7%) in number and arises most frequently from S2 and S3. The nerve to the Levator ani is observed in dogs and rats, but it is not observed in rabbits. The common trunk which is formed by the nerves to the pelvic floor muscles and the pelvic splanchnic nerves is observed in dogs and rats, but it is not observed in rabbits. The number of the nerves to the Obturator internus of dogs, cats and rabbits is either one or two. That of guinea pigs and rats is one. The number of the nerves to the Quadratus femoris of cats and guinea pigs is one. The common trunk which is formed by the originating root of the nerve to the Obturator internus and that of the nerve to the Quadratus femoris is observed in guinea pigs, but it is not observed in cats. The new classification in proposed according to the arising position of the nerve to the Obturator internus and the Quadratus femoris and classified into the following types: Type 1 (sciatic nerve type); the nerve arises from the main trunk of the sciatic nerve or it's originating root. Type 2 (transitional type); the nerve arises from the point where the bigeminal nerve joins the sciatic nerve. Type 3 (pudendal nerve type); the nerve arises from the pudendal nerve or it's originating root. The types most frequently observed are as follows; In dogs, cats, rabbits and rats the nerve to the Obturator internus is pudendal nerve type, and in guinea pigs it is transitional type. In cats the nerve to the Quadratus femoris is pudendal nerve type, and in guinea pigs it is transitional type.

Animals↗
PubMed1986

Interferon inhibits the establishment of competence in Go/S-phase transition.

Addition of mouse interferon-alpha/beta (IFN) to confluent, quiescent BALB/c 3T3 (clone A31) mouse fibroblasts resulted in a block or delay in serum-induced activation of the cell cycle. It was necessary to add IFN within 6 hours after serum stimulation to inhibit nuclear labeling with [3H]thymidine. This is consistent with the time required for platelet-derived growth factor (PDGF) to induce cells to become competent to respond to additional growth factors present in platelet-poor plasma. Simultaneous addition of IFN with PDGF inhibited the PDGF-induced synthesis of a 29-kilodalton and a 35-kilodalton protein that normally occurs within 1 hour after PDGF addition. IFN also suppressed the general increase in protein synthesis that occurs by the fifth hour after PDGF addition. These results show that IFN antagonizes the action of PDGF, thereby interfering with the activation of Go cells for G1 traverse and S-phase entry.

Animals↗
PubMed1986

Interaction between plasma factor XIII and collagen.

Purified plasma Factor XIII efficiently bound to the immobilized collagen affinity column. In contrast, when plasma was applied to the column, as much as 80% of Factor XIII was not trapped. It was shown that the difficulty of binding of Factor XIII in plasma to collagen is not due to the covering of collagen with some plasma proteins. We then assumed that Factor XIII formed a complex in plasma with a certain protein(s), which would prevent Factor XIII from binding to collagen. Using an immobilized Factor XIII affinity column, we have indeed obtained one protein from plasma with apparent Mr of 260,000.

Animals↗
PubMed1986

Platelet factor XIII. The collagen receptor?

We have studied the binding of collagen fibers with platelet proteins using affinity chromatography on collagen-Sepharose. Only a few proteins from a platelet lysate were trapped by this column. When denatured collagen (gelatin) was used as the affinity ligand, the major protein did not bind and was identified as platelet Factor XIII by polyacrylamide gel electrophoresis, immunoprecipitation, and enzymic activity. This is a zymogen form of transglutaminase, which corresponds to the "a" subunit of the coagulation factor in plasma. Immunoglobulins specific for platelet Factor XIII obtained from antiserum raised against plasma Factor XIII were able to initiate platelet aggregation by themselves, in strong contrast to nonspecific antibodies. This specific immunoglobulin-mediated platelet aggregation required the presence of Ca2+. It was inhibited by aspirin and prostacyclin, but not by specific inhibitors for other agonists. These data suggest the possibility that the zymogen form of Factor XIII is located on the surface of platelets and may play a key role as the receptor for collagen-induced platelet aggregation.

Animals↗
PubMed1986

Specific desensitization in the cytoskeletal assembly of platelet by receptor-dependent activations.

Cytoskeletal assembly induced by receptor-dependent or independent activation of bovine platelets was investigated. When platelets were preactivated with receptor-dependent stimulus, ADP or thrombin, cytoskeletal assembly was not induced repeatedly by the same agonist. However, in the case of receptor-independent stimulus, cryo-activation, the assembly was induced not only by receptor-dependent but also by independent stimulus. The desensitization, therefore, lies in the transmission of stimuli from receptors to cytoskeletal proteins.

Actins↗
PubMed1986

An assay for proteoglycanase (PGase) and it's application to articular chondrocyte cultures.

The role of PGase in the degradation of cartilage proteoglycans (PG) is still unclear. Although several assays are available, there still exists some problems in the sensitivity, specificity and simplicity of these procedures. We therefore decided to develop an improved assay for PGase in order to detect small quantities of enzyme activity in the culture medium of articular chondrocytes. As substrates of PGase, we prepared fluorescein isothiocyanate labelled core protein (FITC-PGC) and fluorescein amine labelled hyaluronic acid-proteoglycan subunit complex (FAHA-PGS) from new born calf costal cartilages. PGase activity was estimated from the change of elution profile of Sepharose CL-4B chromatography of fluorescein labelled substrates after incubation with the activated enzyme solution. For measurement of PGase in large numbers of samples, we developed the microultrafiltration method using ultrafiltration membrane (MPS-I kit, Amicon). The concentrated media of articular chondrocyte cultures was used for the investigation of the nature of PGase(s) derived from articular chondrocytes. It was found that APMA, CoCl2, and CaCl2 were needed for activation of the enzyme. Sephadex-G75 gel chromatography of the crude enzyme solution suggests that the molecular weight of PGase from rabbit articular chondrocytes was approximately 5 X 10(4) daltons. From the results of gel chromatography of the digested FITC-PGC and FAHA-PGS it was concluded that one of the sites of attack of the chondrocyte secreted PGase might be near the hyaluronic acid binding region of core protein. The effects of various agents on the production of PGase were also studied. Interleukin-I was found to stimulate PGase production in cultured articular chondrocytes.

Animals↗
PubMed1986

Conversion of muscle fiber types in regenerating chicken muscles following cross-reinnervation.

Slow-tonic anterior latissimus dorsi (ALD) and fast-twitch posterior latissimus dorsi (PLD) muscles of 7 to 10-day-old White Leghorn chickens were crushed and allowed to be reinnervated by their own nerve, or crushed and transplanted to the other side and allowed to be reinnervated by the nerve of the side to which they were transplanted. Following transplantation, changes in the weight of the muscle, fiber-type composition and innervation pattern during regeneration were investigated. Normal growth rate of PLD was about twice that of ALD. Regenerating PLD, however, atrophied rapidly after crushing and denervation whether innervated by its own nerve or the other nerve type, whereas ALD reinnervated by its own nerve showed marked hypertrophy. PLD fibers transformed rapidly to fast-twitch alpha or slow-tonic (ST) fibers when they were reinnervated by PLD or ALD nerve, respectively. When ALD fibers were reinnervated by their own nerve, they differentiated into ST fibers that were surrounded by smaller immature fibers. ALD fibers were, however, resistant to complete control by fast-twitch PLD nerve and contained a large number of slow fibers (ST and beta) long after transplantation. Slow fibers in regenerates were initially multiply innervated, but later transformed into fast-twitch alpha fibers that were focally innervated. The mode of differentiation and innervation pattern of different muscle fiber types in regenerating muscles are discussed.

Acetylcholinesterase↗
PubMed1986

Modification of transglutaminase assay: use of ammonium sulfate to stop the reaction.

An important modification was made of the assay for transglutaminase regarding dansyl cadaverine incorporation into casein. It is known that the amine, after incorporation into protein by transglutaminase, shows a marked increase of fluorescence accompanied by a slight blue shift. However, measurement of protein-bound fluorescence requires a rather complicated procedure, such as the precipitation by trichloroacetic acid or continually monitoring the fluorescence. To widen the applicability of the method, we utilized an excess concentration of ammonium sulfate to stop the reaction. At concentrations higher than 5 mM, the incorporation of the amine was completely stopped and the fluorescence was retained for more than 2 h. The fluorescence can be measured directly after stopping the reaction, so it has become feasible to assay many samples at a time. Furthermore, the sensitivity and reproducibility of the data were improved, since the reaction time could be prolonged and strictly defined.

Ammonium Sulfate↗
PubMed1986

Hemolytic, lethal and edema-forming activities of the skin secretion from the oriental catfish (Plotosus lineatus).

The crude extract from the skin secretion of the oriental catfish, Plotosus lineatus, contained at least one hemolysin, two lethal factors and two edema-forming factors; the lethal and edema-forming factors seem to be identical. The molecular weights of the hemolysin and the lethal factors (edema-forming factors) were estimated to be 180,000 and 12,000, respectively. Peculiar secretory cells, which resembled the venom glandular cells of the dorsal and pectoral stings, were observed in the epidermis.

Animals↗
PubMed1986

Inactivation of calpain I and calpain II by specificity-oriented tripeptidyl chloromethyl ketones.

Three new tripeptidyl chloromethyl ketones, Leu-Leu-XCH2Cl, with X representing Phe, Tyr, or Lys, were synthesized and their potencies to inactivate calpains I and II were compared. They were designed to fulfil the specificity requirement of calpains established recently. When compared in terms of the dose for 50% inactivation, Leu-Leu-PheCH2Cl was the strongest inactivator, being 500-600 times more effective than tosyl-PheCH2Cl and 5-14 times more than N-[N-(L-3-trans-carboxyoxiran-2-carbonyl)-L-leucyl]agmatine (E-64). The potency toward calpain, either I or II, decreased in the order Phe greater than Tyr greater than Lys derivatives greater than E-64, whereas that toward papain was E-64 greater than Lys greater than Phe greater than Tyr derivatives. From the determined kinetic parameters, the Phe derivative was 18.3 and 16.6 times more effective than E-64 on calpains I and II, respectively. Likewise, the rate of the alkylation reaction by these chloromethyl ketones with calpain I was 2-4 times greater than that with calpain II. Leu-Leu-PheCH2Cl and its N-dansylated product should be useful for highly selective affinity labeling of calpains I and II.

Alkylation↗
PubMed1986

Interactions of anticancer quinone drugs, aclacinomycin A, adriamycin, carbazilquinone, and mitomycin C, with NADPH-cytochrome P-450 reductase, xanthine oxidase and oxygen.

The properties of the interactions of anticancer quinone drugs, aclacinomycin A, adriamycin, carbazilquinone, and mitomycin C with nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P-450 reductase and xanthine oxidase under anaerobic and aerobic conditions were studied. Km values of NADPH-cytochrome P-450 reductase for these drugs were in the range of 40-227 microM, and that of deflavo xanthine oxidase in the range of 39-over 200 microM. Under anaerobic conditions, when xanthine was used as an electron donor, deflavo xanthine oxidase catalyzed the reductive glycosidic cleavage reaction of anthracyclines and nicotinamide adenine dinucleotide was ineffective as an electron donor. In the electron spin resonance study, the formation of the semiquinone or free radical state of the quinone drugs in both enzyme systems were evidenced. A weak and symmetric signal was obtained from aclacinomycin A, and a symmetric signal from adriamycin was changed into an asymmetric and strong. The hyperfine structure was obtained from carbazilquinone in the oxidase system. In the studies of ultraviolet-visible spectra of the quinone drugs in the reductase system, the spectra of aclacinomycin A and adriamycin were changed to their 7-deoxylaglycones, and the formation of small amounts of the fully reduced form were observed after long incubations. The spectrum of carbazilquinone was changed to the hydroquinone form and mitomycin C was converted into mitosene analogues. Under aerobic conditions, superoxide radicals and hydrogen peroxide were effectively produced in the presence of anticancer quinone drugs in both enzyme systems. The superoxide-dependent hydroxy radical production, which was measured by ethylene production from methional, was observed in the presence of aclacinomycin A and adriamycin in the deflavo xanthine oxidase system. From these results, the possible reactions in the interactions of anticancer quinone drugs with these enzymes and oxygen are discussed.

Aclarubicin↗
PubMed1986

Effects of glucose and amino acid depletions on protein synthetic parameters in liver and skeletal muscle of rats during parenteral nutrition.

Rats were nourished by intravenous infusion of four different experimental solutions: total parenteral nutrition (TPN) solution (group I); glucose-depleted TPN solution (group II); amino acid-depleted TPN solution (group III); and glucose- and amino acid-depleted TPN solution (group IV). All except group I animals lost body weight and showed negative nitrogen balance during a 7-day experimental period; glucose-depleted groups II and IV generally suffered more severely than amino acid-depleted group III. However, the concentration of plasma albumin in group III was significantly lower than that in the other groups. The weights of liver and gastrocnemius muscles after 7 days of infusion with different nutrient compositions were fairly well correlated with the RNA/DNA ratios in these tissues. Infusion of nutritionally deficient solutions caused progressive disaggregation of polysomes in both liver and gastrocnemius muscles, indicating variable degrees of impairment of protein synthesis in these tissues. The changes in polysomal profiles were rapid and sensitive; the polysomal disaggregation was evident within one day of infusion with deficient solutions. The determination of polysomal profiles in various tissues may be useful in optimizing the composition of TPN solutions.

Amino Acids↗
PubMed1986

[Tactile point identification].

The ability to identify spatially tactile point stimuli was examined, under simultaneous or sequential presentation, using a 3 X 3 matrix of vibrotactile stimulators placed against the abdomen. The first experiment showed that the performance of tactile point identification deteriorated with the increase of the number of tactile point stimuli, especially under the simultaneous presentation. The obtained memory span was about two stimulus positions in the simultaneous presentation and about 4.5 in the sequential presentation. In the second experiment, a tactile version of the Hogben-Di Lollo paradigm (1974) was employed to investigate processing rate of tactile point identification. The ability in identifying the missing tactile stimulus position was found to be an increasing function of SOA, reaching asymptote at about 600 ms SOA. A subsidiary task of counting backwards by threes made performance poorer. The analysis of errors indicated the existence of a short-term tactile memory.

Abdomen↗