Biomedical subjects

Y Takada

Publications and source records attributed to Y Takada.

At least 73 records · Page 4Linked to original sources

PubMed2001

Molecular aspects of self-incompatibility in Brassica species.

Many flowering plants possess self-incompatibility (SI) systems to prevent inbreeding. SI in Brassica species is controlled by a single S locus with multiple alleles. In recent years, much progress has been made in determining the male and female S determinant in Brassica species. In the female, a gain-of-function experiment clearly demonstrated that SRK was the sole S determinant, and that SLG enhanced the SI recognition process. By contrast, the male S determinant (termed SP11/SCR) was identified in the course of genome analysis of S locus to be a small cysteine-rich protein, which was classified as a pollen coat protein. This SP11/SCR may function as a ligand for the S domain of SRK in the SI recognition reaction of Brassica species.

Brassica↗

PubMed2001

Protection against Fas-mediated and tumor necrosis factor receptor 1-mediated liver injury by blockade of FADD without loss of nuclear factor-kappaB activation.

OBJECTIVE: To investigate the role of FADD (Fas-associated protein with death domain) in Fas and tumor necrosis factor receptor 1 (TNFR1)-mediated hepatic injury and inflammatory response in vivo. SUMMARY BACKGROUND DATA: Fas and TNFR1 are cell surface molecules that trigger apoptosis or inflammation on engagement by a specific ligand or antibody. FADD is recruited to the cytoplasmic domain of these receptors on their activation and works as a common mediator to induce apoptosis. It is known that a blockade of FADD can inhibit apoptosis mediated by Fas or TNFR1 in vitro. However, it is not known whether the blockade can prevent organ injury and whether the inflammatory cascade is affected in vivo. METHODS: A FADD deletion mutant lacking the death effector domain was introduced into mice by transduction with an adenovirus vector, and the effect of this FADD dominant negative mutant was examined in several liver injury models. RESULTS: Hepatic injury induced by anti-Fas monoclonal antibody or tumor necrosis factor (TNF)-alpha plus D-galactosamine was markedly ameliorated by the FADD dominant negative transduction, which abrogated the death rate. Further, the FADD dominant negative transduction efficiently blocked T cell- mediated concanavalin A-induced hepatitis while not affecting TNF-alpha production or TNF-alpha-induced nuclear factor-kappaB activation in the liver. CONCLUSIONS: These results provide the basis for a novel therapeutic modality in which an unfavorable apoptotic process can be inhibited without affecting a favorable response for liver regeneration; this would be relevant to the clinical treatment of acute and chronic liver diseases as well as to some inflammatory disorders with hypercytokinemia, such as sepsis.

Adaptor Proteins, Signal Transducing↗

PubMed2001

The detection of bacteria and bacterial biofilms in punctal plug holes.

PURPOSE: An investigation into bacterial biofilm formation on and in punctal plugs. METHODS: The study involved 21 patients with severe dry eye whose puncta were occluded by the use of punctal plugs. Of these, 15 had Sjögren's syndrome, 3 had non-Sjögren's syndrome, 2 had Stevens-Johnson syndrome, and 1 had graft-versus-host disease. From 17 of the 21 subjects, 18 samples of material were extracted from the holes of the punctal plugs (16 unilateral and 1 bilateral) and were subjected to enrichment culture. Nineteen punctal plugs were removed and processed for electron microscopy: 15 by scanning electron microscopy, and 4 by transmission electron microscopy. RESULTS: Positive cultures were found in 8 of 18 (44%) samples of the material extracted from the holes of punctal plugs. In six of these eight cases (75%) the cultured bacterial species was Staphylococcus epidermidis, whereas in the other two cases (25%) it was S. aureus. In 8 of the 15 punctal plugs examined by scanning electron microscopy and in the material extracted from 1 plug that was examined by transmission electron microscopy, there was clear evidence of bacterial colonization. CONCLUSION: Careful observation of patients with punctal plugs is important. If material accumulates in or on a punctal plug, it may contain bacteria and may form a bacterial biofilm. In these cases, replacement of the plug, clearing of the hole, or an alternative treatment should be considered.

Adult↗

PubMed2001

Tissue-type plasminogen activator is involved in the process of neuronal death induced by oxygen-glucose deprivation in culture.

Effect of tissue-type plasminogen activator (tPA) on oxygen-glucose deprivation (OGD) was studied in cultured cortical neurons prepared from tPA gene knockout (tPA-KO) and wild-type (Wt) mice. Three hours of OGD induced 45% and 23% of neuronal death in Wt and tPA-KO mice, respectively. Neuronal death in tPA-KO mice was increased to 42% by additional tPA. Six hours of OGD induced 80% and 40% of neuronal death in Wt and tPA-KO mice, respectively, whereas the addition of tPA increased to 62% in tPA-KO mice. These results suggest that tPA is directly involved in the process of neuronal death induced by ischemia-mimic stress without involving vascular or circulatory components.

Animals↗

PubMed2001

Long-term results of donor-specific blood transfusion with cyclosporine in living related kidney transplantation.

Donor-specific blood transfusion (DST) was introduced to achieve better graft survival. However, its benefits are controversial considering the immunosuppression of cyclosporine (CYA) or tacrolimus (Tac), and its long-term effects have not been well discussed. Of the 40 patients who received DST with CYA, 3 (7.5%) became cross-match positive. Of the 37 patients with negative cross-match, 34 patients received a one-haplotype-matched kidney and were compared to patients with one-haplotype-matched kidney transplant without preoperative DST (n = 13). Acute rejection within 3 months after transplant was 29.4% in the DST group, and 15.4% in the non-DST group. All rejection episodes were steroid resistant in the non-DST group. If the graft survival rates were calculated excluding non-immunological graft loss, graft survival rate was 91.0 and 72.8% at 5 and 10 years in the DST group, and 83.3% at 5 and 10 years in the non-DST group, respectively. The two graft survival lines converged 7 years and 7 months after transplantation. No beneficial effect of DST was statistically evident under CYA immunosuppression. In terms of the severity of acute rejection or the onset of chronic rejection, DST induced a small benefit, however, which seemed to disappear within 8 years after transplantation.

Acute Disease↗

PubMed2001

Activation-recovery intervals of 12-lead electrocardiograms before and after catheter ablation in patients with Wolff-Parkinson-White syndrome.

Preexcitation in Wolff-Parkinson-White syndrome (WPW) has been reported to induce long-lasting changes in ventricular recovery properties. However, there has not been a report concerning changes in the activation-recovery interval (ARI) in 12-lead ECGs before and after catheter ablation (CA) in patients with WPW syndrome. The present study compared changes in ARIs from 12-lead ECGs with those from body surface unipolar leads before and after CA to examine whether ARIs from limb leads of 12-lead ECGs provide useful information on changes in recovery properties in addition to the ARIs from precordial leads. The study population consisted of 27 manifest WPW patients with a left- (n=18, group A) or right-sided accessory pathway (n=9, group B). ARIs in leads I, II, and III were strongly correlated with those in unipolar leads over the left lateral, left lower, and right lower chest, respectively. ARIs in leads aVR, aVL, and aVF showed a significant correlation with those in unipolar leads over the right upper, left upper, and lower anterior chest, respectively. These correlations were maintained before and after CA. Furthermore, in group A, ARIs in lead V1 tended to increase on day 7 post CA compared with before CA and on day 1. In group B, ARIs in lead III significantly decreased on day 7 compared with before CA and on day 1. These findings suggest that ARIs from the limb leads of 12-lead ECGs may represent those from unipolar leads of a particular area over the body surface, and that ARIs from 12-lead ECGs may provide useful quantitative information on changes in recovery properties before and after CA in patients with manifest WPW syndrome.

Adolescent↗

PubMed2001

Purification and characterization of a cold-adapted isocitrate lyase and a malate synthase from Colwellia maris, a psychrophilic bacterium.

Isocitrate lyase (ICL) and malate synthase (MS) of a psychrophilic marine bacterium, Colwellia maris, were purified to electrophoretically homogeneous state. The molecular mass of the ICL was found to be 240 kDa, composed of four identical subunits of 64.7 kDa. MS was a dimeric enzyme composed of 76.3 kDa subunits. N-Terminal amino acid sequences of the ICL and MS were analyzed. Purified ICL had its maximum activity at 20 degrees C and was rapidly inactivated at the temperatures above 30 degrees C, but the optimum temperature for the activity of MS was 45 degrees C. NaCl was found to protect ICL from heat inactivation above 30 degrees C, but the salt did not stabilize MS. Effects of temperatures on the kinetic parameters of both the enzymes were examined. The Km for the substrate (isocitrate) of ICL was decreased with decreasing temperature. On the other hand, the Km for the substrate (glyoxylate) of MS was increased with decreasing temperature. The calculated value of free energy of activation of ICL was on the same level as that of MS.

Cold Temperature↗

PubMed2001

Milk basic protein promotes bone formation and suppresses bone resorption in healthy adult men.

Milk contains several components effective for bone health. In the previous in vitro and in vivo studies, we have shown that milk whey protein, especially its basic protein fraction (milk basic protein [MBP]), promoted bone formation and suppressed bone resorption. This present study examines the effect of MBP on the biochemical markers of bone metabolism in healthy adult men. Experimental beverages containing MBP (300 mg of MBP a day) were given to 30 normal healthy adult men for 16 days. The serum osteocalcin concentration had increased significantly after 16 days of ingesting the experimental beverage containing MBP. Urinary cross-linked N-teleopeptides of type-I collagen (NTx) excretion had decreased significantly after 16 days of ingesting MBP. The urinary NTx excretion was related to the serum osteocalcin concentration after 16 days of ingestion. These results suggest that MBP promoted bone formation and suppressed bone resorption, while maintaining the balance of bone remodeling.

Adult↗

PubMed2001

Controlled trial of the effects of milk basic protein (MBP) supplementation on bone metabolism in healthy adult women.

Milk has more beneficial effects on bone health compared to other food sources. Recent in vitro and in vivo studies showed that milk whey protein, especially its basic protein fraction, contains several components capable of both promoting bone formation and inhibiting bone resorption. However, the effects of milk basic protein (MBP) on bone metabolism of humans are not known. The object of this study was to examine the effects of MBP on bone metabolism of healthy adult women. Thirty-three normal healthy women were randomly assigned to treatment with either placebo or MBP (40 mg per day) for six months. The bone mineral density (BMD) of the left calcaneus of each subject was measured at the beginning of the study and after six months of treatment, by dual-energy x-ray absorptiometry. Serum and urine indices of bone metabolism were measured at the base line, three-month intervals, and the end of the study. Daily intake of nutrients was monitored by a three-day food record made at three and six months. The mean (+/- SD) rate of left calcaneus BMD gain of women in the MBP group (3.42 +/- 2.05%) was significantly higher than that of women in the placebo group (2.01 +/- 1.75%, P = 0.042). As compared with the placebo group, urinary cross-linked N-teleopeptides of type-I collagen/creatinine and deoxypyridinoline/creatinine were significantly decreased in the MBP group (p < 0.05), while no significant differences between the two groups were observed in serum osteocalcin and bone-specific alkaline phosphatase concentrations. A daily MBP supplementation of 40 mg in healthy adult women can significantly increase their BMD independent of dietary intake of minerals and vitamins. This increase in BMD might be primarily mediated through inhibition of osteoclast-mediated bone resorption by the MBP supplementation.

Absorptiometry, Photon↗

PubMed2001

Effects of various insecticides on the development of the egg parasitoid Trichogramma dendrolimi (Hymenoptera: Trichogrammatidae).

The toxicity of six insecticides, acephate, methomyl, ethofenprox, cartap, chlorfluazuron, and Bacillus thuringiensis (Bt) was tested on different developmental stages of the egg parasitoid, Trichogramma dendrolimi (Matsumura). Each of the insecticides tested showed different degrees of toxicity to the parasitoid, Ethofenprox showed the highest toxicity and cartap showed relatively higher toxicity compared with the other insecticides. The development of the parasitoids treated with these two insecticides was normal, similar to that of the control group. Only the emergence of adult wasps from host eggs was disturbed. Emergence of the host, Mamestra brassicae larva was reduced following treatment with ethofenprox, cartap and methomyl. However, adult female wasps, which emerged from host eggs treated with the insecticides had the ability to oviposit normally.

Animals↗

PubMed2001

Carboplatin calculated with Chatelut's formula plus etoposide for elderly patients with small-cell lung cancer.

OBJECTIVE: This dose escalation was conducted to evaluate the applicability of Chatelut's dosing, and to determine the efficacy and toxicity of carboplatin with etoposide in previously untreated elderly patients (>70 years) with small cell lung cancer. PATIENTS AND METHODS: Seventeen patients were treated with etoposide for 3 days and carboplatin calculated dose using Chatelut's formula on day 1 intravenously. The starting doses of etoposide on days 1 to 3, and carboplatin using the area under the concentration versus time curve (AUC) were 90 mg/m2 and 4 mg/ml x min, respectively. RESULTS: The median age was 77 years (range 71 to 87). Dose-limiting toxicity (DLT) was seen at level 4 (AUC 5 mg/ml x min of carboplatin and etoposide 100 mg/m2). Hematologic toxicity was the primary DLT. Grade 4 thrombocytopenia and Grade 4 leukopenia were observed at level 4. Non-hematologic toxicity was insignificant. The overall response rate was 94%. CONCLUSION: Etoposide at 100 mg/m2 and AUC of carboplatin of 4.5 mg/ml x min as calculated using Chatelut's formula every four weeks is the recommended dose for further phase II trials for elderly patients with small cell lung cancer.

Aged↗

PubMed2001

Microstructure and corrosion behavior of binary titanium alloys with beta-stabilizing elements.

Binary titanium alloys with the beta-stabilizing elements of Co, Cr, Cu, Fe, Mn and Pd (up to 30%) and Ag (up to 45%) were examined through metallographic observation and X-ray diffractometry to determine whether beta phases that are advantageous for dental use could be retained. Corrosion behavior was also investigated electrochemically and discussed thermodynamically. Some cast alloys with Co, Cr, Fe, Mn, and Pd retained the beta phase, whereas those with Ag and Cu had no beta phase. In some alloys, an intermetallic compound formed, based on information from the phase diagram. The corrosion resistance deteriorated in the TiAg alloys because Ti2Ag and/or TiAg intermetallic compounds preferentially dissolved in 0.9% NaCl solution. On the other hand, the remaining titanium alloys became easily passive and revealed good corrosion resistance similar to pure titanium since their matrices seemed to thermodynamically form titanium oxides as did pure titanium.

Analysis of Variance↗

PubMed2001

[Refractory non-small-cell lung cancer responding to combination chemotherapy with docetaxel, gemcitabine and cisplatin].

The combination of docetaxel (TXT), gemcitabine (GEM), and cisplatin (CDDP) produced a regression in a squamous cell carcinoma of the lung that had recurred after radiation therapy plus chemotherapy, and was resistant to the combination of carboplatin (CBDCA) with etoposide (ETP) or paclitaxel (TXL). The patient was a 62-year-old man with squamous cell lung cancer, which was first successfully treated by a combination of radiation therapy and chemotherapy, but showed local recurrence after 8 months. Although the recurrence was treated with CBDCA plus ETP and then TXL, the tumor continued to grow with symptomatic progression of airway stenosis. The tumor began to regress after the regimen of TXT, GEM and CDDP was started. This therapy achieved PR with symptomatic improvement. The combination of TXT, GEM and CDDP may be effective for recurrent non-small-cell lung carcinoma, even in patients that have failed to respond to more than one chemotherapy regimen.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2001

[A case of unilateral moyamoya disease presenting with hemichorea].

We reported a 12-year-old boy with unilateral moyamoya disease whose initial and predominant manifestation was hemichorea. Neurological examinations revealed chorea in his left upper extremity and muscle hypotonia in his left upper and lower extremities. Cranial MRI showed moyamoya vessels only in the right basal ganglia and infarction in the white matter of the right frontal lobe. Right carotid angiography revealed stenosis in the distal part of internal carotid artery, and in the proximal part of anterior and middle cerebral arteries with moyamoya vessels. Left carotid angiography showed normal findings. He was diagnosed as a suspected case of moyamoya disease (unilateral moyamoya disease) according to the diagnostic criteria proposed by the Research Committee on Moyamoya Disease of the Ministry of Health and Welfare of Japan. His chorea responded to haloperidol but encephalo-duro-arterio-synangiosis on the right side improved all symptoms. Chorea occurs in some patients with moyamoya disease. Hypofunction of the striatal indirect pathway is suggested as the cause of chorea. In this case an ischemic lesion in the right striatum may have caused hypofunction of the pathway and developed chorea and hypotonia.

Cerebral Angiography↗

PubMed2001

Primary stages in photosignal transduction leading to step-up photophobic response in the unicellular eukaryote Blepharisma japonicum.

In order to elucidate the primary stage in the blepharismin phototransduction pathway, changes in the molecular structure of light-exposed blepharismins and oxyblepharismins, were examined. When exposed to light, blepharismins (pink form) were converted into oxyblepharismins (blue form) or dissociated into stentorins/p-hydroxybenzaldehyde with an O2-requiring process, whereas light-exposed oxyblepharismins were not dissociated into stentorins/p-hydroxybenzaldehyde. Since both blepharismins and oxyblepharismins can activate the phototransduction chain leading to the step-up photophobic response presumably through the same pathway, dissociation of p-hydroxybenzaldehyde may not be involved in signal transduction. The fact that the step-up photophobic response requires O2, and both blepharismins and oxyblepharismins produce hydroxyl (OH) radicals probably derived from O2 implies that OH radicals may activate the photosignalling pathway. The step-up photophobic response was not suppressed by a spin trapping reagent for hydroxyl radicals. Other possible primary responses leading to the step-up photophobic response are discussed.

Animals↗

PubMed2001

Mechanisms of integrin-mediated virus attachment and internalization process.

Viruses that propagate within vertebrate hosts have adapted many strategies to infect host cells. One of the first steps in a viral infection is the binding of the virus to cell surface molecules. This interaction between a virus and its receptors plays a key role in the multiplication cycle. Entry of viruses into cells is a complex, multistep process, and for several viruses, cell attachment and internalization are distinct steps. A number of virus receptors have been identified; a common family of viral receptors is the integrin family. Integrins are a widely expressed family of cell adhesion receptors, by which cells attach to extracellular matrices; they also mediate important cell-cell adhesion events. Integrins are involved in a number of tissue remodeling events, including embryogenesis, angiogenesis, wound repair, and bone resorption. In addition, several integrins are used by manyviruses in theirinfectious cycle. Virus-integrin interactions maybe more complex than previously thought because several viruses can interact with unique integrin regions or can activate distinct signaling pathways. This article will discuss the strategies devised by many viruses in their integrin-mediated attachment or cell entry.

Adenoviridae↗

PubMed2000

Importance of GlcUAbeta1-3GalNAc(4S,6S) in chondroitin sulfate E for t-PA- and u-PA-mediated Glu-plasminogen activation.

Chondroitin sulfate E (CSE) markedly enhanced plasminogen activation by tissue plasminogen activators (t-PAs) and urinary plasminogen activator (u-PA) in vitro; in the presence of 10 microg/ml of CSE, the potentiation factors of single chain of t-PA, two chain of t-PA and u-PA were 400, 140 and 130, respectively. Though the potentiation activity of CSE gradually decreased when it was depolymerized by chondroitinase ABC, the specific disaccharide from CSE still showed significant activity. Glycosaminoglycan (GAG) from sea cucumber, which possesses a very similar core structure to CSE, but has additional sulfated fucose branches exhibit very weak activity. These results suggested that the minimal structural requirement in CSE to enhance plasminogen activation by plasminogen activators is GlcUAbeta1-3GalNAc(4S,6S) and that additional branching sugars abolish the activity.

Animals↗

PubMed2000

RGD-independent binding of integrin alpha9beta1 to the ADAM-12 and -15 disintegrin domains mediates cell-cell interaction.

ADAMs (a disintegrin and metalloproteases) mediate several important processes (e.g. tumor necrosis factor-alpha release, fertilization, and myoblast fusion). The ADAM disintegrin domains generally lack RGD motifs, and their receptors are virtually unknown. Here we show that integrin alpha(9)beta(1) specifically interacts with the recombinant ADAMs-12 and -15 disintegrin domains in an RGD-independent manner. We also show that interaction between ADAM-12 or -15 and alpha(9)beta(1) supports cell-cell interaction. Interestingly, the cation requirement and integrin activation status required for alpha(9)beta(1)/ADAM-mediated cell adhesion and cell-cell interaction is similar to those required for known integrin-extracellular matrix interaction. These results are quite different from recent reports that ADAM-2/alpha(6)beta(1) interaction during sperm/egg fusion requires an integrin activation status distinct from that for extracellular matrix interaction. These results suggest that alpha(9)beta(1) may be a major receptor for ADAMs that lack RGD motifs, and that, considering a wide distribution of ADAMs and alpha(9)beta(1), this interaction may be of potential biological and pathological significance.

ADAM Proteins↗