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Biomedical subjects

T Moriguchi

Publications and source records attributed to T Moriguchi.

At least 19 recordsLinked to original sources

Changes in free polyamine titers and expression of polyamine biosynthetic genes during growth of peach in vitro callus.

In the present paper, correlation between free polyamines and growth of peach (Prunus persica cv. Yuzora) in vitro callus was investigated. Growth of the callus was divided into three phases based on measurement of fresh weight. Free polyamines, putrescine (Put), spermidine (Spd), and spermine (Spm), could be detected during peach callus growth. Changes in free Put titers followed the callus growth rate, as shown by low and stable levels in the first stage, quick increase at the beginning of the second phase, and slow increase in the last phase, whereas fluctuations of Spd and Spm titers were aberrant from that of Put at early stage. Expressions of five key genes involved in polyamine biosynthesis were characterized, in which only the genes leading to Put synthesis, ADC (arginine decarboxylase) and ODC (ornithine decarboxylase), agreed with callus growth and fluctuation of Put titers. Treatment of the callus with D-arginine, an inhibitor of ADC, led to significant growth inhibition and enormous reduction of endogenous Put, coupled with obvious decrease of mRNA levels of ADC and ODC. Exogenous application of Put partially restored the callus growth, along with resumption of endogenous Put and expression levels of ADC and ODC. Spd and Spm titers experienced minor change in comparison to Put. The data presented here suggested that free Put played an important part in peach callus growth. Putative mechanisms or mode of action underlying the role of Put in peach callus growth and different expression patterns of the genes responsible for polyamine biosynthesis are also discussed.

Arginine↗

Reliability and validity of DESIGN, a tool that classifies pressure ulcer severity and monitors healing.

OBJECTIVE: This study reviews the validity and reliability of DESIGN, a tool for classifying pressure ulcer severity and monitoring progression towards healing. Only the tool's healing progression component was evaluated. METHOD: Inter-rater reliability was evaluated by calculating the agreement rate of scores, based on eight photos of pressure ulcers and six actual ulcers, made by a panel of seven nurses. Validity was assessed, using the same eight photos, by comparing DESIGN scores with those made using the validated Pressure Sore Status Tool (PSST). RESULTS: The DESIGN inter-rater reliability results showed a high correlation of r = 0.98 for the photos and r = 0.91 for the real-life patients with pressure ulcers, respectively, for all seven raters based on total scores. For validity, a correlation greater than 0.91 was found between the DESIGN and PSST scores. CONCLUSION: Based on our results, DESIGN was found to have both high inter-rater reliability and high validity among the seven nurses who quantitatively evaluated the wound-healing progress of the pressure ulcers in this study.

Humans↗

Elucidation of adsorption mechanism of bone-staining agent alizarin red S on hydroxyapatite by FT-IR microspectroscopy.

To elucidate adsorption mechanism of alizarin red S (ARS), which is often used for staining bones in histology, adsorption of ARS on hydroxyapatite, Ca10(PO4)6(OH)2 (HAP), was investigated by a batch method, compared with alizarin, phenols, and benzenesulfonates. We found that ionized 1-, 2-OH groups (1-, 2-O(-)) of ARS can be electrostatically bound to Ca2+ on HAP, but that the 3-SO3(-) group of ARS hardly participates in adsorption on HAP. ARS-adsorbed HAP (ARS-HAP) in dark reddish violet was also prepared and analyzed by FT-IR microspectroscopy to gain structural information on bonding between ARS and HAP. The obtained spectrum, which was converted to difference spectra, indicated a single band of nu(C=O) at 1627 cm(-1) and two types of symmetric C=O stretching bands of nu(s)(C=O) + nu(C=C) at 1345 cm(-1) and nu(s)(C=O) + delta(O-C=C) at 1272 cm(-1). These bands imply the existence of a salt form in ARS-HAP via 1-, 2-OH groups of ARS. As a result of the existence of a chelate form in ARS-HAP via 1-OH and 9-C=O groups of ARS, two bands of nu(C=C) + nu(C=O) at 1572 cm(-1) and nu(C=O) + nu(C=C) at 1537 cm(-1) were also observed. In addition, ARS was almost desorbed from colored ARS-HAP at 50 degrees C by using neutral phosphate buffer to recover slightly pale pinkish HAP, or De-ARS-HAP. The desorbed ARS belongs to ARS previously adsorbed on HAP by salt formation, while the remaining color on De-ARS-HAP indicates ARS still adsorbed on HAP by chelate formation. Consequently, we elucidated two adsorption mechanisms of ARS on HAP: The major adsorption is salt formation made up with 1-, 2-O(-) of ARS and Ca2+ on HAP, and the minor adsorption is chelate formation made up with 1-O(-) and 9-C=O of ARS and Ca2+ on HAP.

Adsorption↗

Structure and expression of spermidine synthase genes in apple: two cDNAs are spatially and developmentally regulated through alternative splicing.

Three cDNAs (MdSPDS1, 2a and 2b) encoding spermidine synthase (SPDS), a key enzyme in the polyamine biosynthesis, have been cloned from apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.]. The deduced amino acid sequences of their protein products share 76-83% identity with SPDSs of other higher plants. A comparison of the sequences of the three cDNAs and of the two corresponding genomic DNA fragments (SPDS1 and SPDS2) indicated that MdSPDS1 was transcribed from the SPDS1 sequence, whereas MdSPDS2a and MdSPDS2b were both derived from SPDS2 by alternative splicing. To learn more about the physiological roles of MdSPDS1, MdSPDS2a and MdSPDS2b, Northern analyses were carried out, together with measurements of polyamine content. Levels of both MdSPDS1 and MdSPD2a were higher in young leaves than in mature leaves and shoots. In fruits, mRNA levels were nearly as high as in young leaves and remained high during fruit development. By RT-PCR, MdSPDS2b transcripts were detected in mature leaves and shoots, but not in young leaves and fruits. These results indicate that MdSPDS2a and MdSPDS2b are differentially regulated in a tissue- and developmentally specific manner. The content of free polyamines in mesocarp tissues was measured at five stages of fruit development. At all stages, spermidine (Spd) was the predominant form of polyamine. The level of Spd was high at the early growth stage and declined to about 90% during later developmental stages. The possible regulation of SPDS expression during apple fruit development is discussed.

Alternative Splicing↗

Mice lacking the M3 muscarinic acetylcholine receptor are hypophagic and lean.

Members of the muscarinic acetylcholine receptor family (M1-M5) have central roles in the regulation of many fundamental physiological functions. Identifying the specific receptor subtype(s) that mediate the diverse muscarinic actions of acetylcholine is of considerable therapeutic interest, but has proved difficult primarily because of a lack of subtype-selective ligands. Here we show that mice deficient in the M3 muscarinic receptor (M3R-/- mice) display a significant decrease in food intake, reduced body weight and peripheral fat deposits, and very low levels of serum leptin and insulin. Paradoxically, hypothalamic messenger RNA levels of melanin-concentrating hormone (MCH), which are normally upregulated in fasted animals leading to an increase in food intake, are significantly reduced in M3R-/- mice. Intra-cerebroventricular injection studies show that an agouti-related peptide analogue lacked orexigenic (appetite-stimulating) activity in M3R-/- mice. However, M3R-/- mice remained responsive to the orexigenic effects of MCH. Our data indicate that there may be a cholinergic pathway that involves M3-receptor-mediated facilitation of food intake at a site downstream of the hypothalamic leptin/melanocortin system and upstream of the MCH system.

Animals↗

Olfactory discrimination deficits in n-3 fatty acid-deficient rats.

Docosahexaenoic acid (DHA), a long chain n-3 fatty acid, is present in high concentrations in the central nervous system. Although the role that DHA may play in neural function is not well understood, infants fed formulas containing low levels of n-3 fatty acids have decreased visual acuity and neurodevelopmental test scores. The present experiment assessed whether dietary manipulations that decrease the concentration of DHA in the brain interfered with olfactory-based learning. We fed rats a diet that provided adequate n-3 fatty acids or a diet that was deficient in n-3 fatty acids for two generations. The second generation n-3-deficient group had 81% less brain DHA (82% less in olfactory bulb) compared to the n-3-adequate group and made significantly more errors in a series of olfactory-cued, 2-odor discrimination tasks compared to the adequate group. These results suggest that lower levels of central nervous system DHA lead to poorer performance in a series of simple odor discrimination tasks.

Animals↗

The effects of aged garlic extract on lipid peroxidation and the deformability of erythrocytes.

The effects of aged garlic extract (AGE) on lipid peroxidative damage and the deformability of erythrocytes were evaluated in rats. The deformability of erythrocytes was measured using the micropore filtration method. AGE significantly prevented the decrease of erythrocyte deformability induced by lipid peroxidation in a dose-dependent manner. The addition of AGE significantly inhibited an increase in thiobarbituric acid-reactive substances (TBARS) and hemolysis rate and prevented the loss of intraerythrocytic ATP and 2,3-diphosphoglycerate (2,3-DPG) in oxidized erythrocytes. Moreover, AGE significantly suppressed not only the hemolysis rate induced by peroxidation but also hemolysis due to nonperoxidation. These results suggest the possibility that AGE improves microcirculation and rheological blood properties and preserves the structure and function of erythrocytes not only through an antioxidant process, but also via the glycolysis pathway and membrane stabilization of erythrocytes.

2,3-Diphosphoglycerate↗

Ameliorative effect of S-allylcysteine, a major thioallyl constituent in aged garlic extract, on learning deficits in senescence-accelerated mice.

This study examined the effect of S:-allylcysteine (SAC), a major thioallyl compound found in aged garlic extract, on the memory deficit and age-related changes of senescence-accelerated mice. Senescence-accelerated prone P8 mice fed a diet supplemented with 40 mg SAC/kg diet for 8 mo had a significantly attenuated decrease in the conditioned avoidance response compared with those not given SAC. In the elevated plus-maze test using senescence-accelerated prone P10 mice, the percentage of time spent on the open arm was greater compared with the senescence-resistant control mice. Chronic dietary treatment with 40 mg SAC/kg diet decreased the time in the open arm in senescence-accelerated prone P10 mice. These studies suggest that diet supplementation with SAC may reduce age-related learning disabilities and cognitive disorders in senescence-accelerated mice.

Aging↗

Investigation of antisense DNA having C-5 polyamine substituted 2'-deoxyuridine derivative.

Phosphorothioate analogs of oligodeoxyribonucleotide (S-ODN) bearing non-branched polyamine molecule at C-5 position of certain pyrimidine base were synthesized. The synthesis of the modified S-ODNs was accomplished via post-synthetic modification method utilizing C-5 methoxycarbonylmethyl substituted deoxyuridine derivative with modest yields. The thermal stability of the dulexes containing modified S-ODNs was assessed through the measurement of the melting points (Tms). Interestingly, the Tms of the modified oligomers were considerably lower than that of the corresponding unmodified oligomer at relatively high concentration range. At lower concentration, on the other hand, the Tms of the modified S-ODNs were higher than that of the unmodified oligomer.

Anti-HIV Agents↗

Synthesis of small multifunctional molecules having nucleic acid binding property.

We have previously reported that a multifunctional conjugate having the acridine derivative as an intercalative molecule and the polyamine moiety as an RNA cleaving molecule bound to a double helical RNA and cleaved the target efficiently. Along the study to develop a sequence and site specific artificial RNA cleaving molecule, we have development a novel intercalative molecule having polyamine moiety and DNA connecting function. The trisamine-acridine-tethered DNA is expected to bind to the complementary RNA and cleave the phosphodiester bond of the RNA near the position of the built-in interecalator.

Acridines↗

Mixed lineage kinase LZK forms a functional signaling complex with JIP-1, a scaffold protein of the c-Jun NH(2)-terminal kinase pathway.

Leucine zipper-bearing kinase (LZK) is a novel member of the mixed lineage kinase (MLK) protein family, the cDNA of which was first cloned from a human brain cDNA library [Sakuma, H., Ikeda, A., Oka, S., Kozutsumi, Y., Zanetta, J.-P., and Kawasaki, T. (1997) J. Biol. Chem. 272, 28622-28629]. Several MLK family proteins have been proposed to function as MAP kinase kinase kinases in the c-Jun NH(2) terminal kinase (JNK)/stress-activated protein kinase (SAPK) pathway. In the present study, we demonstrated that, like other MLKs, LZK activated the JNK/SAPK pathway but not the ERK pathway. LZK directly phosphorylated and activated MKK7, one of the two MAPKKs in the JNK/SAPK pathway, to a comparable extent to a constitutive active form of MEKK1 (MEKK1DeltaN), suggesting a biological role of LZK as a MAPKKK in the JNK/SAPK pathway. Recent studies have revealed the essential roles of scaffold proteins in intracellular signaling pathways including MAP kinase pathways. JIP-1, one of the scaffold proteins, has been shown to be associated with MLKs, MKK7, and JNK [Whitmarsh, A.J., Cavanagh, J., Tournier, C., Yasuda, J., and Davis, R.J. (1998) Science 281, 1671-1674], suggesting the presence of a selective signaling pathway including LZK, MKK7, and JNK. Consistent with this hypothesis, we provided evidence that LZK is associated with the C-terminal region of JIP-1 through its kinase catalytic domain. In addition, LZK-induced JNK activation was markedly enhanced when LZK and JNK were co-expressed with JIP-1. These results constituted important clues for understanding the molecular mechanisms regulating the signaling specificities of various JNK activators under different cellular conditions.

Adaptor Proteins, Signal Transducing↗

One-stage facial augmentation with an intraoral groin adipose flap transfer.

A free groin adipose flap using an intraoral approach was used to correct facial contour deformities instead of a groin dermis-fat flap. The major disadvantages of the latter flap are that multistage debulking procedures are required and there are wide postoperative donor scars because of the wide skin portion included in the flap. To overcome these weaknesses the authors developed a free groin, customized ("berry picked") adipose flap, which was transferred by an intraoral approach for reconstruction of congenital hemifacial (orbitozygomatic) hypoplasia. The advantages of this method include one-stage augmentation without secondary defatting, no skin grafting of the donor defect, a donor scar in a concealed area, and possible transfer through an intraoral approach that results in minimal invasive surgery with no scar at the graft site.

Adipose Tissue↗

Free medial plantar perforator flaps for the resurfacing of finger and foot defects.

In this article, three cases in which free medial plantar perforator flaps were successfully transferred for coverage of soft-tissue defects in the fingers and foot are described. This perforator flap has no fascial component and is nourished only by perforators of the medial plantar vessel and a cutaneous vein or with a small segment of the medial plantar vessel. The advantages of this flap are minimal donor-site morbidity, minimal damage to both the posterior tibial and medial plantar systems, no need for deep dissection, the ability to thin the flap by primary removal of excess fatty tissue, the use of a large cutaneous vein as a venous drainage system, a good color and texture match for finger pulp repair, short time for flap elevation, possible application as a flow-through flap, and a concealed donor scar.

Adolescent↗

Free tensor fasciae latae perforator flap for the reconstruction of defects in the extremities.

In the three cases presented in this study, free tensor fasciae latae perforator flaps were used successfully for the coverage of defects in the extremities. This flap has no muscle component and is nourished by muscle perforators of the transverse branch of the lateral circumflex femoral system. The area of skin that can by nourished by these perforators is larger than 15 x 12 cm. The advantages of this flap include minimal donor-site morbidity, the preservation of motor function of the tensor fasciae latae muscle and fascia lata, the ability to thin the flap by removing excess fatty tissue, and a donor scar that can be concealed. In cases that involve transection of the perforator above the deep fascia, the operation can be completed in a very short period of time. This flap is especially suitable as a free flap for young women and children who have scars in the proximal region of the lateral thigh or groin region that were caused by split-thickness skin grafting or full-thickness skin grafting during previous operations.

Adult↗