Biomedical subjects

H Takeshima

Publications and source records attributed to H Takeshima.

At least 73 records · Page 4Linked to original sources

PubMed1999

Type 3 and type 1 ryanodine receptors are localized in triads of the same mammalian skeletal muscle fibers.

The type 3 ryanodine receptor (RyR3) is a ubiquitous calcium release channel that has recently been found in mammalian skeletal muscles. However, in contrast to the skeletal muscle isoform (RyR1), neither the subcellular distribution nor the physiological role of RyR3 are known. Here, we used isoform-specific antibodies to localize RyR3 in muscles of normal and RyR knockout mice. In normal hind limb and diaphragm muscles of young mice, RyR3 was expressed in all fibers where it was codistributed with RyR1 and with the skeletal muscle dihydropyridine receptor. This distribution pattern indicates that RyR3 is localized in the triadic junctions between the transverse tubules and the sarcoplasmic reticulum. During development, RyR3 expression declined rapidly in some fibers whereas other fibers maintained expression of RyR3 into adulthood. Comparing the distribution of RyR3-containing fibers with that of known fiber types did not show a direct correlation. Targeted deletion of the RyR1 or RyR3 gene resulted in the expected loss of the targeted isoform, but had no adverse effects on the expression and localization of the respective other RyR isoform. The localization of RyR3 in skeletal muscle triads, together with RyR1, is consistent with an accessory function of RyR3 in skeletal muscle excitation-contraction coupling.

Aging↗

PubMed1999

Spatiotemporal dynamics of inositol 1,4,5-trisphosphate that underlies complex Ca2+ mobilization patterns.

Inositol 1,4,5-trisphosphate (IP3) is a second messenger that elicits complex spatiotemporal patterns of calcium ion (Ca2+) mobilization and has essential roles in the regulation of many cellular functions. In Madin-Darby canine kidney epithelial cells, green fluorescent protein-tagged pleckstrin homology domain translocated from the plasma membrane to the cytoplasm in response to increased concentration of IP3. The detection of translocation enabled monitoring of IP3 concentration changes within single cells and revealed spatiotemporal dynamics in the concentration of IP3 synchronous with Ca2+ oscillations and intracellular and intercellular IP3 waves that accompanied Ca2+ waves. Such changes in IP3 concentration may be fundamental to Ca2+ signaling.

Adenosine Triphosphate↗

PubMed1999

Nociceptin system plays a role in the memory retention: involvement of naloxone benzoylhydrazone binding sites.

We investigated the role of nociceptin system in learning and memory in mice. The deficiency of nociceptin receptors and nociceptin itself did not affect the alternation behavior in the Y-maze test. In the passive avoidance test, the step-through latencies of nociceptin receptor knockout mice were longer than those of wild-type mice. Nociceptin shortened the step-through latency in wild-type mice. This impairment on passive avoidance task was reversed by naloxone benzoylhydrazone (NalBzoH), indicating that the amnesic effects of nociceptin may be mediated through the NalBzoH recognition sites. These suggest that nociceptin system plays an important role in the memory retention of passive avoidance task, and NalBzoH-recognized sites are involved in nociceptin-induced impairment of the memory retention.

Animals↗

PubMed1999

RhoN, a novel small GTP-binding protein expressed predominantly in neurons and hepatic stellate cells.

A cDNA encoding a novel member of the small molecular weight GTP-binding protein (small G-protein) superfamily was cloned from rat spinal cord. The deduced amino acid sequence was highly homologous with those of so-far-known Rho proteins. Rho proteins were reported to alter many important cellular functions including formation of both actin stress fibers and focal adhesions. RNA blot hybridization and in situ hybridization analyses indicated that the novel small G-protein is expressed specifically in neurons in the brain and spinal cord and also in hepatic stellate cells. Based on the sequence similarity and neuron-specific expression in the brain, this protein was named RhoN. Unlike classical Rho proteins, RhoN was not susceptible to the ADP-ribosylation reaction by C3 botulinum toxin. Accordingly, RhoN seemed to be specifically involved in neuronal and hepatic functions as a C3 toxin-insensitive member of the Rho subfamily. Then, a mouse genomic DNA segment containing the RhoN gene was cloned. The locus was mapped on the mouse chromosome 11C-D. The sequence data showed that the protein-coding sequence for RhoN is divided by 4 introns, and that the defined 5 exons may encode intramolecular domains serving for different functions.

Adenosine Diphosphate Ribose↗

PubMed1999

Cloning and functional characterization of the 5'-flanking region of the human monocyte chemoattractant protein-1 receptor (CCR2) gene. Essential role of 5'-untranslated region in tissue-specific expression.

The human monocyte chemoattractant protein-1 receptor designated hCCR2 is an essential co-receptor in cell entry by the human immunodeficiency virus as well as a receptor for monocyte chemoattractant protein-1, a member of the family of C-C chemokines that mediate monocyte chemotaxis. To elucidate the molecular mechanisms underlying the transcriptional regulation of hCCR2, we cloned and sequenced the hCCR2 gene; it was approximately 8 kilobase pairs in length and consisted of three exons divided by two introns. In the 5'-flanking region, there were the typical mammalian promoter consensus elements, a CAAT box and a TATA box, resulting in a single transcription initiation site. In addition, we found clustered tissue-specific cis-regulatory elements such as GATA consensus sequences, Oct-1 binding sequences, and CAAT/enhancer-binding protein binding sequences. Luciferase assays with various promoter deletions and gel mobility shift assays indicated that three cis-regulatory elements located within the region from -89 to +118 are required for basal activity in THP-1 cells. One element is an octamer sequence 36-base pair upstream from the TATA box; it binds mainly to Oct-1 and is capable of increasing transcriptional activity. The other two elements, which are tandem recognition sites of the CAAT/enhancer-binding protein family, are located in the 5'-untranslated region and account for the transcriptional activation as well as the tissue specificity of hCCR2.

5' Untranslated Regions↗

PubMed1999

Immunolocalization of mitsugumin29 in developing skeletal muscle and effects of the protein expressed in amphibian embryonic cells.

The temporal appearance and subcellular distribution of mitsugumin29 (MG29), a 29-kDa transmembrane protein isolated from the triad junction in skeletal muscle, were examined by immunohistochemistry during the development of rabbit skeletal muscle. MG29 appeared in the sarcoplasmic reticulum (SR) in muscle cells at fetal day 15 before the onset of transverse tubule (T tubule) formation. In muscle cells at fetal day 27, in which T tubule and triad formation is ongoing, both SR and triad were labeled for MG29. In muscle cells at newborn 1 day, the labeling of the SR had become weak and the triads were well developed and clearly labeled for MG29. Specific and clear labeling for MG29 was restricted to the triads in adult skeletal muscle cells. When MG29 was expressed in amphibian embryonic cells by injection of the cRNA, a large quantity of tubular smooth-surfaced endoplasmic reticulum (sER) was formed in the cytoplasm. The tubular sER was 20-40 nm in diameter and appeared straight or reticular in shape. The tubular sER was formed by the fusion of coated vesicles [budded off from the rough-surfaced endoplasmic reticulum (rER)] and vacuoles of rER origin. The present results suggest that MG29 may play important roles both in the formation of the SR and the construction of the triads during the early development of skeletal muscle cells.

Amphibians↗

PubMed1999

Expression and functional characterization of the cardiac muscle ryanodine receptor Ca(2+) release channel in Chinese hamster ovary cells.

To study the function and regulation of the cardiac ryanodine receptor (RyR2) Ca(2+) release channel, we expressed the RyR2 proteins in a Chinese hamster ovary (CHO) cell line, and assayed its function by single channel current recording and confocal imaging of intracellular Ca(2+) ([Ca(2+)](i)). The 16-kb cDNA encoding the full-length RyR2 was introduced into CHO cells using lipofectAmine and electroporation methods. Incorporation of microsomal membrane vesicles isolated from these transfected cells into lipid bilayer membrane resulted in single Ca(2+) release channel activities similar to those of the native Ca(2+) release channels from rabbit cardiac muscle SR membranes, both in terms of gating kinetics, conductance, and ryanodine modification. The expressed RyR2 channels were found to exhibit more frequent transitions to subconductance states than the native RyR2 channels and RyR1 expressed in CHO cells. Caffeine, an exogenous activator of RyR, induced release of [Ca(2+)](i) from these cells. Confocal imaging of cells expressing RyR2 did not detect spontaneous or caffeine-induced local Ca(2+) release events (i.e., "Ca(2+) sparks") typically seen in cardiac muscle. Our data show that the RyR2 expressed in CHO cells forms functional Ca(2+) release channels. Furthermore, the lack of localized Ca(2+) release events in these cells suggests that Ca(2+) sparks observed in cardiac muscle may involve cooperative gating of a group of Ca(2+) release channels and/or their interaction with muscle-specific proteins.

Animals↗

PubMed1999

Lower urinary tract function after intra-arterial chemotherapy with concurrent pelvic radiotherapy for invasive bladder cancer.

BACKGROUND: Intra-arterial chemotherapy with concurrent pelvic radiotherapy as a bladder-sparing regimen for invasive bladder cancer is highly promising for selected patients. However, lower urinary tract function after this treatment has not been fully investigated. METHODS: The urodynamic effects of intra-arterial chemotherapy with concurrent pelvic radiotherapy were retrospectively evaluated in 14 patients with organ-confined invasive bladder cancer. The post-treatment urodynamic findings were compared with the pretreatment ones (n = 7), and a comparison was made between the serial urodynamic findings after the treatment in another seven patients who were able to undergo the pretreatment urodynamic study (UDS). RESULTS: The median follow-up period up to the latest UDS was 34 months. Of the 14 patients, the latest UDS revealed some storage dysfunctions in 11 (79%) and some emptying dysfunctions in three (23%). Uninhibited detrusor contraction and decreased bladder compliance were recorded in 29 and 43% at the pretreatment UDS and approximately 50-60 and 20-60% in the serial follow-up studies, respectively (n = 7). Impaired detrusor contractility lasted in one patient. In the seven patients without the pretreatment UDS, decreased maximum cystometric capacity and decreased compliance were recorded in approximately 50-60 and 20-60% at the serial UDS, respectively. Detrusor contractility was aggravated in one patient and completely lost in one with time. CONCLUSIONS: The urodynamic findings indicate that the bladder-sparing regimen might result in perpetuating the lower urinary tract dysfunctions due to invasive bladder cancer itself and/or transurethral surgery and might injure the infrasacral autonomic nerves and the bladder itself.

Aged↗

PubMed1999

Contractile function is unaltered in diaphragm from mice lacking calcium release channel isoform 3.

Skeletal muscle expresses at least two isoforms of the calcium release channel in the sarcoplasmic reticulum (RyR1 and RyR3). Whereas the function of RyR1 is well defined, the physiological significance of RyR3 is unclear. Some authors have suggested that RyR3 participates in excitation-contraction coupling and that RyR3 may specifically confer resistance to fatigue. To test this hypothesis, we measured contractile function of diaphragm strips from adult RyR3-deficient mice (exon 2-targeted mutation) and their heterozygous and wild-type littermates. In unfatigued diaphragm, there were no differences in isometric contractile properties (twitch characteristics, force-frequency relationships, maximal force) among the three groups. Our fatigue protocol (30 Hz, 0.25 duty cycle, 37 degrees C) depressed force to 25% of the initial force; however, lack of RyR3 did not accelerate the decline in force production. The force-frequency relationship was shifted to higher frequencies and was depressed in fatigued diaphragm; lack of RyR3 did not exaggerate these changes. We therefore provide evidence that RyR3 deficiency does not alter contractile function of adult muscle before, during, or after fatigue.

Animals↗

PubMed1999

Cerebral gumma showing spontaneous regression on magnetic resonance imaging study--case report.

A 75-year-old male presented with the complaint of headache. Magnetic resonance (MR) imaging demonstrated a low-signal intensity area on both T1- and T2-weighted images with ring-like enhancement and adhesion of the dura appearing as dural tail sign. Follow-up MR imaging demonstrated spontaneous regression, so the preoperative diagnosis was malignant lymphoma. Histological examination revealed typical granuloma. Treponema pallidum hemagglutination assay tests of serum and cerebrospinal fluid were positive for active syphilis. The enhanced mass totally disappeared after 4 months of erythromycin therapy. The final diagnosis was cerebral gumma. The incidence of syphilis is increasing, so cerebral gumma should be included in the differential diagnosis of hypovascular tumors that involve both the parenchyma and dura even in the presence of spontaneous regression.

Aged↗

PubMed1999

Expression of p120 nucleolar proliferating antigen in human gliomas and growth suppression of glioma cells by p120 ribozyme vector.

p120 is a nucleolar proliferating antigen which is expressed in tumor cells but not normal resting cells. The expression and localization of p120 in human gliomas were studied by Northern blot analysis, Western blot analysis and immunohistochemistry. All five of the glioma cell lines and all of the glioma specimens we investigated expressed p120 at both the mRNA and protein levels. p120 expression was not detected in adjacent brain tissues. A ribozyme vector was constructed to cleave the first GUC sequence in the coding region of p120 mRNA. This p120 ribozyme vector was transfected into the glioma cell line SF188, which expresses p120. The reduced p120 expression of the transfectant at both the mRNA and protein levels was confirmed. An MTT assay indicated that the transfected cells grew more slowly than control cells. These results indicate that i) p120 has an important role in the proliferation of gliomas, and ii) the ribozyme against p120 mRNA can suppress glioma cell growth.

Base Sequence↗

PubMed1999

[The critical appraisal of QOL questionnaire for prostate cancer patients].

BACKGROUND: Prostate cancer is a common malignancy that affects Japanese elderly men. Its incidence is increasing, recently, and its treatments are various. The measurement of quality of life (QOL) has become important for the evaluation of and selection of treatments. In Japan, however, there is no standard way of measuring QOL for prostate cancer patients, except the Japanese version of the EORTC QOL questionnaire for prostate cancer patients. We examined the validity and feasibility of this translated EORTC QOL questionnaire for prostate cancer patients. METHODS: Sixty-nine prostate cancer patients who were under treatment in 4 hospitals were selected for this study. We applied the content validity, the factorial validity which was analyzed by the oblique principal component cluster analysis, the internal consistency analyzed by the alpha coefficient of Cronbach, the convergent validity which was used GHQ, IPSS and PS as external measures, and the feasibility. RESULTS: This questionnaire showed good internal consistency, as the alpha coefficient was 0.61 to 0.90 in all domains, except for sex life, which was the lowest. This questionnaire was classified into 7 clusters by the oblique principal component cluster analysis. Consequently, the factorial validity was good, except for items regarding sex life. As domains correlate well with external measures except in sex life, the convergent validity was good. It was suggested that only two items were not acceptable in regard to the content validity and the feasibility, and that the translation into Japanese of 2 items was inadequate. CONCLUSIONS: Our study suggests that the Japanese version of the EORTC QOL questionnaire for prostate cancer patients demands improvement for the practical employment in clinical trials, as there is a problem of translation and feasibility.

Aged↗

PubMed1999

[Development of Japanese version of QOL questionnaire for bladder and prostate cancer patients using FACT-Bl and P: pilot study].

BACKGROUND: Quality of life (QOL) has been known to be a prognostic factor as well as the endpoint of treatment efficacy in many clinical fields. We have begun a US-Japan collaborative project introducing a QOL questionnaire, the FACT (Functional Assessment of Cancer Therapy), into Japan. We report on the translation process, results of the pilot study, and future plans for translating the Japanese version of the FACT subscales, FACT-Bl (for bladder cancer) and FACT-P (for prostate cancer). METHODS: The FACT translation procedure, which is quite rigorous, follows a four-step methodology. After completing the translations, we tested the translated FACT-G (general questionnaire) and subscales for bladder and prostate cancer patients. The questionnaires were tested on 30 outpatients at Tsukuba University Hospital (15 bladder, 15 prostate). The only eligibility requirement to participate in the study was a confirmed diagnosis of cancer of the bladder or prostate. RESULTS AND DISCUSSION: There was satisfactorily high internal consistency of FACT-G of both bladder and prostate cancer patients. FACT-Bl study included patients having undergone radical cystectomy as well as those who had not. Because not all items were answered by all patients, the Cronbach's alpha coefficient for the FACT-Bl subscale could not be computed. Further evaluation of the FACT-Bl concerning the surgical procedures affecting QOL is needed. We are currently planning to make the further refinement of the questionnaire in order to make it more suitable for bladder cancer patients. FACT-P subscale had an alpha coefficient of 0.82 and was determined to be useful in its present form.

Aged↗

PubMed1999

[A case of synchronous multifocal urothelial tumors in a patient with phenacetin abuse].

A 79-year-old male with phenacetin abuse was admitted to our University Hospital for treatment of asymptomatic gross hematuria. Intravenous urograpdy and computed tomography revealed synchronous right renal pelvic carcinoma and bladder carcinoma. Right nephroureterectomy and transurethral resection of bladder tumor (TUR-Bt) were performed. Histologically, right renal pelvic tumor and bladder tumor were both transitional cell carcinomas of grade 2, pT1, and grade 1 = 2, Ta, respectively. Additionally, pathological examination revealed two distal ureteral tumors, which were transitional cell carcinomas of grade 2, pTa. He also had a history of heavy tobacco-smoking (20 cigarettes per day for 50 years). We discuss the relationship between transitional cell carcinoma and phenacetin abuse as well as the influence of tobacco-smoking, and review the literature.

Aged↗

PubMed1999

[Cases of refractory testicular cancer treated with all trans-retinoic acid].

We reported two cases of chemotherapy-refractory testicular cancer treated with all trans-retinoic acid (ATRA). Case 1. A 21-year-old male patient underwent salvage surgery for lung metastasis which had developed after treatment with three different cisplatin-based chemotherapy regimens for malignant teratoma. After recovery from surgery, he was treated with oral ATRA at daily dose 80 mg/m2 for four weeks. Case 2. A-45-year-old patient suffered from lung metastasis after orchiectomy for teratocarcinoma. The patient failed to achieve a complete response despite two different cisplatin-based chemotherapy and high dose chemotherapy regimens with bone marrow rescue. He was treated with oral ATRA for five weeks. Both patients showed disease progression with increase in tumor size and elevation of tumor marker during ATRA therapy. Side effects were acceptable except the headache in Case 2, who needed a dose reduction of ATRA. In conclusion, oral ATRA with this dose failed to show clinical antitumor activity in patients with refractory testicular cancer.

Adult↗

PubMed1999

Dose-related opposite modulation by nociceptin/orphanin FQ of substance P nociception in the nociceptors and spinal cord.

We previously reported that the intraplantar (i.pl.) application of nociceptin/orphanin FQ (N/OFQ) at extremely low doses elicited a nociception through a substance P (SP) release from nociceptor endings. In the present study, the nociception induced by SP (and N/OFQ) was abolished by intrathecal (i.t.) injection of neurokinin(1) (SP receptor) antagonist, suggesting the involvement of the stimulation of nociceptive primary SP neuron and SP release into spinal synapses. On the other hand, similar low doses of N/OFQ (i.t.) exerted nociceptive responses, characterized by scratching, biting, and licking, and these responses were blocked by an neurokinin(1) antagonist (i.t.) or capsaicin pretreatment or in tachykinin 1 gene knockout mice (tac1(-/-) mice), suggesting that N/OFQ receptor (NOR) also exists on the spinal terminals of SP neurons. When wide ranges of N/OFQ doses were used, a typical bell-shaped dose-response relationship was observed in both peripheral and central nociception tests. Furthermore, N/OFQ (1 nmol) administered i.pl. blocked SP (i.pl.)-induced flexor responses, which were abolished by pertussis toxin pretreatment or in NOR gene knockout (NOR(-/-)) mice. On the other hand, N/OFQ administered i.t. blocked SP (i.t.)-induced scratching, biting, and licking in capsaicin-pretreated and tac1(-/-) mice, and this antinociception was abolished in NOR(-/-) mice. All these findings suggest that N/OFQ has biphasic actions depending on doses in the nociceptors and spinal synapses and has postsynaptic antinociceptive actions in spinal cord by modulating SP signaling.

Analgesics↗

PubMed1999

[Short- and long-term outcome after urethroplasty in the patients with hypospadias treated by Hodgson III method].

Between 1977 and 1997, 29 patients with hypospadias were surgically treated by Hodgson type III urethroplasty at Tsukuba University Hospital. The duration of surgery ranged from 150 to 535 minutes with an average of 269.3 minutes and the urethral catheter was removed between 4 and 14 days (average 8.7 day) after surgery. The postoperative hospital stay ranged from 10 to 29 days with an average of 18.4 days. The overall success rate of initial surgery was observed in 18 of the 29 patients (62.1%). As early postoperative complications, urethral fistula and stricture were seen in 10 (34%) and 3 (10%) patients, respectively; of these four fistulas persisted. As late complications revealed by questionnaire, erectile disorder was observed in one case. To obtain a higher success rate on initial treatment, skillful surgical technique and selection of appropriate cases are required.

Adolescent↗

PubMed1999

Prognostic significance of the MIB-1 labeling index for patient with craniopharyngioma.

Proliferative activity of 17 craniopharyngiomas were determined using an immunohistochemical method with monoclonal antibody MIB-1. A considerable variation of the MIB-1 labeling indices was found between the different tumors with a minimum of 0.4% and a maximum of 32.5% (median, 10.84%). The mean MIB-1 labeling index (LI) for 4 craniopharyngiomas that showed no evidence of recurrence (n=4) was 3.4 +/- 2.3%. This was significantly lower than that for craniopharyngiomas that showed recurrence and regrowth (13.2 +/- 7.7%) (n=13), based on the initial resected tumors. Statistical analysis reveal that craniopharyngiomas with an MIB-1 LI of 7% or more have a significantly high tendency for recurrence and regrowth during clinical course. Our data suggest that a MIB-1 LI greater than 7% may be a useful predictor of regrowth/recurrence of craniopharyngiomas and may be useful for planning of adjuvant therapy.

Adolescent↗