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Biomedical subjects

K Tashiro

Publications and source records attributed to K Tashiro.

At least 289 records · Page 16Linked to original sources

Role of nitric oxide in non-adrenergic, non-cholinergic relaxation and modulation of excitatory neuroeffector transmission in the cat airway.

1. The effects of nitrosocysteine (cys-NO), L-N omega-nitroarginine (L-NNA) and L-N omega-nitro-L-arginine methylester (L-NAME), oxyhaemoglobin and Methylene Blue were observed on the resting membrane potential, muscle tone and excitatory junction potentials (EJPs) of cat tracheal smooth muscle tissue. 2. Cys-NO (10(-9) to 10(-6) M) showed no effect on the resting membrane potential of smooth muscle cells of the cat trachea but it dose-dependently relaxed the tracheal tissue in the presence of 5-HT, atropine and guanethidine. 3. Electrical field stimulation (EFS) applied during contraction evoked by 5-HT in the presence of atropine and guanethidine evoked non-adrenergic, non-cholinergic (NANC) muscle relaxation. L-NNA (10(-4) M) and L-NAME (10(-4) M) completely suppressed the relaxation when single or short repetitive stimuli were applied, but suppression was incomplete with repetitive stimuli of 4 ms pulse duration applied at 20 Hz. A substantial part of the L-NNA- or L-NAME-insensitive relaxation was abolished by tetrodotoxin. 4. Cys-NO dose-dependently suppressed the EJPs without changing the resting membrane potential, and L-NNA, L-NAME, Methylene Blue and oxyhaemoglobin enhanced the amplitude of the EJP to 1.2-1.5 times the control value. 5. EJPs showed some summation when repetitive field stimulation was applied at 20 Hz. L-NNA or L-NAME enhanced the summation, and the mean slopes were increased from 0.61 +/- 0.22 to 2.0 +/- 0.3, or 1.9 +/- 0.2 mV per stimulus. Vasoactive intestinal polypeptide (VIP) antiserum and VIP antagonists further enhanced the summation in the presence of L-NNA. 6. These results indicate that NANC relaxation can be classified into two different components according to the threshold for activation, and nitric oxide is involved in one. The present results also suggest that endogenous or exogenous nitric oxide has a prejunctional action in inhibiting excitatory neuroeffector transmission in addition to a direct action on the smooth muscle cells, presumably by suppressing transmitter release from the vagus nerve.

Animals↗

Cloning of cDNA and genomic DNA encoding fibroblast growth factor receptor-4 of Xenopus laevis.

We have isolated and characterized the cDNA and genomic DNA encoding fibroblast growth factor receptor-4 of Xenopus laevis (XFGFR-4). The gene encompassing the total coding sequence spans about 10 kb, consists of 17 exons, and has an organization very similar to those of mammalian genes encoding FGFR-1 and -2, except that the XFGFR-4 gene does not contain an alternative exon for the third immunoglobulin-like domain nor an internal poly(A)-addition site. Thus, XFGFR-4 appears not to generate multiple forms of mRNA, as are identified for the mammalian FGFR-1, -2 and -3 genes. The amino-acid sequence of XFGFR-4 shows high homology to other vertebrate FGFR-4 species, but the similarity was significantly lower than in the cases of FGFR-1 and -2. Northern blot analysis showed the XFGFR-4 mRNA to occur throughout X. laevis early embryogenesis in a profile different from those of X. laevis FGFR-1 and -2.

Amino Acid Sequence↗

Spinocerebellar ataxia 1 (SCA1) in the Japanese: analysis of CAG trinucleitide repeat expansion and instability of the repeat for paternal transmission.

SCA1 is caused by expansion of an unstable CAG triplet repeat in a novel gene located on the short arm of chromosome 6. In 126 Japanese individuals from 12 pedigrees with SCA1, studies were done to determine if they carried this mutant gene. All the affected and pre-symptomatic individuals, determined by haplotype segregation analyses, carried an abnormally expanded allele with the range of 39-63 repeat units. This repeat size inversely correlated with the age at onset. However, contrary to reported results, size of the repeat did not correlate with gender of the transmitting parent. Therefore, the CAG triplet repeat instability on paternal transmission is not likely to be fundamental to SCA1.

Adolescent↗

Macrophage inflammatory protein-1 alpha in the cerebrospinal fluid of patients with multiple sclerosis and other inflammatory neurological diseases.

The level of macrophage inflammatory protein-1 alpha (MIP-1 alpha), a newly discovered cytokine of chemokine family, was determined in cerebrospinal fluid (CSF) from 18 patients with multiple sclerosis (MS) and from control patients with other neurological disorders by an enzyme-linked immunosorbent assay (ELISA). The concentration of MIP-1 alpha in CSF was significantly elevated in MS in relapse (4.4 pg/ml) compared with non-inflammatory neurological disease control samples (0.3 pg/ml) (p < 0.0002). These concentrations in MS patients correlated well with leukocyte cell counts and protein content in CSF (r = 0.845, p < 0.0001; r = 0.853, p < 0.0001, respectively). In other inflammatory neurological disorders such as Behçet's disease and HTLV-1 associated myelopathy, significantly increased CSF levels of MIP-1 alpha were also observed. Chemokines are reported to play an important role in an early event of inflammation such as lymphocyte traffic. This report is the first study which confirmed the involvement of a chemokine in MS and other inflammatory neurological disorders.

Adult↗

CAG repeat expansion of Machado-Joseph disease in the Japanese: analysis of the repeat instability for parental transmission, and correlation with disease phenotype.

Machado-Joseph disease (MJD) is caused by abnormal expansion of an unstable CAG repeat in a novel gene locating on chromosome 14q32.1. We analysed this CAG repeat polymorphism with 66 Japanese MJD patients. All the patients were selectively associated with abnormal expansion of the CAG repeat. Repeat length of the mutant allele did not overlap that of normal allele and closely correlated with not only age at onset but also with clinical phenotypes. CAG repeat size is apparently related to a wide variety of phenotypic presentations in MJD.

Adult↗

Stimulation of circus movement by activin, bFGF and TGF-beta 2 in isolated animal cap cells of Xenopus laevis.

Lobopodium is a hyaline cytoplasmic protrusion which rotates circumferencially around a cell. This movement is called circus movement, which is seen in dissociated cells of amphibian embryos. Relative abundance of the lobopodia-forming cells changes temporally and spatially within Xenopus embryos, reflecting stage-dependent difference of morphogenetic movements. The lobopodia-forming activity of dissociated animal cap cells was stimulated strongly by activin and bFGF, and weakly by TGF-beta 2. In addition, activin A was found to stimulate cellular attachment to the substratum when the cultivation lasted long. Thus, mesoderm-inducing growth factors stimulate lobopodia formation and cellular movements which may be necessary for gastrulation and neurulation in Xenopus early embryos.

Activins↗

Molecular cloning of Xenopus HGF cDNA and its expression studies in Xenopus early embryogenesis.

We isolated Xenopus HGF cDNA and examined its expression pattern in Xenopus early embryos and their dissected parts. Xenopus HGF consists of 710 amino acids and contains four kringle domains and serine protease-like structure just like mammalian HGF. Northern blot analysis showed that expression of Xenopus HGF mRNA starts at the late gastrula stage and its level increases during the period of later embryogenesis. Dissection experiments revealed that Xenopus HGF mRNA is expressed in the mesoderm region, especially in the ventral mesoderm, which for the most part gives rise to mesenchymal cells. Furthermore, HGF mRNA was expressed in response to activin A and basic FGF in blastula animal cap cells. Interestingly, a stronger activity was observed with bFGF than with activin and this finding corroborates the preferential expression of HGF mRNA in the ventral mesoderm. Based on these results, we conclude that the Xenopus homologue of HGF gene is transcribed during early embryogenesis preferentially in ventral mesodermal tissues, probably in response to the signals that induce ventral mesoderm.

Amino Acid Sequence↗

Surfactant replacement reverse respiratory failure induced by intratracheal endotoxin in rats.

OBJECTIVE: To evaluate the effect of surfactant replacement on respiratory failure induced by intratracheal injection of endotoxin in rats. DESIGN: Prospective, randomized study. SETTING: Laboratory at a large university. SUBJECTS: Male Wistar rats, weighing 353 +/- 50 (SD) g. INTERVENTIONS: Escherichia coli endotoxin (53 +/- 19 mg/kg) was injected into the trachea of 32 rats anesthetized with pentobarbital and mechanically ventilated with an FIO2 of 1.0. After PaO2 decreased to < 200 torr (< 26.7 kPa), the rats were assigned to three groups: a) a surfactant group (n = 16), given a modified natural surfactant suspension (100 mg/kg in 2.0 mL/kg of saline) by instillation into the airway; b) a saline control group (n = 8), given 2.0 mL/kg of saline; and c) an air control group (n = 8), given 2.0 mL/kg of air. An additional nine rats were ventilated in the same way but were not given endotoxin. MEASUREMENTS AND MAIN RESULTS: Among the rats receiving endotoxin, the PaO2 of the saline and air control groups remained < 200 torr (< 26.7 kPa), while PaO2 of the surfactant group increased to 390 +/- 116 torr (52.0 +/- 15.5 kPa; p < .05 vs. the preassignment value) 15 mins after the assignment. These high levels were maintained throughout the experiment. Surfactant replacement also led to significant improvements in the PaCO2, the dynamic lung-thorax compliance, the pressure-volume recordings of the lung, and the chest roentgenograms. Histologic examination showed that the alveoli of the surfactant group were better aerated than the alveoli of the control groups. Findings in the rats not given endotoxin were almost normal, indicating that the influences of mechanical ventilation were negligible. CONCLUSION: Surfactant replacement reversed respiratory failure induced by intratracheal injection of endotoxin in rats.

Animals↗

Spinocerebellar ataxia 1 (SCA1) in the Japanese in Hokkaido may derive from a single common ancestry.

Spinocerebellar ataxia 1 (SCA1) is caused by expansion of an unstable CAG triplet repeat located on the short arm of chromosome 6. Precise mapping has shown a positional relationship to closely linked markers in the order of D6S109-D6S274-D6S288-SCA1-AM10GA-D6S89+ ++-EDN1 from centromere to telomere. The haplotype which cosegregated with the disease was determined in 12 Japanese pedigrees with SCA1. Although the alleles of the SCA1 haplotype varied from pedigree to pedigree, depending on the distance from the SCA1 locus, the affected and presymptomatic subjects carried the same alleles at D6S288 and D6S274. All the families with SCA1 had migrated from either Miyagi or Yamagata Prefectures, neighbouring areas in the Tohoku District, the northern part of Honshu which is the main island of Japan. It seems highly likely that SCA1 in the Japanese, at least those residing in Hokkaido, derives from a single common ancestry.

Chromosome Mapping↗

Erdheim-Chester disease and slowly progressive cerebellar dysfunction.

A 59 year old woman developed pronounced thirst, increased water intake, and increased urinary output followed by slowly progressive cerebellar symptoms. Brain MRI showed abnormal hyperintensity on T2 weighted studies in the region of both dentate nuclei without atrophy of the cerebellum or the brainstem. A 99mTC diphosphonate bone scan showed bone lesions in the distal parts of both femurs as well as distal and proximal parts of both tibias. The diagnosis of Erdheim-Chester disease was made by bone biopsy. This is the first case of Erdheim-Chester disease presenting as a slowly progressive cerebellar syndrome and diabetes insipidus, and also showing high signal lesions in deep cerebellar nuclei on MRI. Skeletal surveys are indicated for patients with otherwise unexplained slowly progressive cerebellar symptoms.

Bone Diseases↗

Binding capacity of serum IgA to jacalin in patients with IgA nephropathy using jacalin-coated microplates.

Binding capacity of serum IgA to jacalin in 22 patients with IgA nephropathy, 14 patients with diffuse mesangial proliferative glomerulonephritis (non-IgA nephropathy) and 20 age-matched healthy adults was examined by enzyme-linked immunoassay (ELISA) using jacalin-coated microplates. In contrast to previous findings, the binding capacity of serum IgA to jacalin in patients with IgA nephropathy measured by ELISA using jacalin-coated microplates was significantly higher than that in healthy adults. The ratio of serum IgA levels measured by this method to those obtained by single radial immunodiffusion was significantly increased in patients with IgA nephropathy. It appeared that the capacity of serum IgA binding to jacalin was marked in these patients. It is concluded that the binding capacity of serum IgA to jacalin is not ubiquitously impaired in all patients with IgA nephropathy.

Adult↗

[An analysis of factors related to recurrence of superficial bladder cancer after transurethral resection].

A total of 205 patients with primary superficial bladder cancer (Ta, T1) followed more than 3 years were retrospectively analyzed for factors related to recurrence of tumors after transurethral resection. Patients age were 25 to 90 years old, average 61 years old, and there were 160 males and 45 females. Initial tumor grades were G0 in 4 patients, G1 in 48, G2 in 134 and G3 in 19. Seventy four patients had Ta tumor and 131 had T1. Initial treatments were transurethral resection (TUR) alone in 137 patients. TUR with intravesical chemotherapy in 64, with BCG therapy in 7 and others in 7. Factors examined included age, sex, chief complaint, shape, size, and number of tumors, tumor distribution (single area or multiple area), histological grade, stage and intravesical chemotherapy. Overall non-recurrent rate were 81.7% at 1 year, 60.7% at 3 year, 53. 8% at 5 year and 44.2% at 8 year. Five-year non-recurrent rate according tumor factors, showed significant difference regarding tumor size (< 1 cm or 1 cm <: P = 0.027), tumor number (single or multiple: P = 0.004), tumor distribution (single area or multiple area: p = 0.002), histological grade (< G1 or G2 < : p = 0.001) and stage (Ta or T1: p = 0001). However, there were no significant difference regarding factors of age, sex, chief complaint, tumor figure and presence or absence of intravesical chemotherapy. This results suggested that the tumor factors of size, number, tumor distribution, grade and stage were highly related to intravesical tumor recurrence of superficial bladder cancer.

Adult↗

[A study of tumor location and prognosis in renal pelvic and ureteral cancer].

A total of 245 patients with renal pelvic and ureteral cancer (transitional cell carcinoma) were retrospectively analysed for tumor location and prognosis. In 133 renal pelvic cancer patients, 34 patients (25.6%) had tumor in lower calyx, 33 patients (24.8%) in renal pelvis, 31 patient (23.3%) in upper calyx, 21 patients (15.8%) in whole renal pelvis and 7 patients (5.2%) in middle calyx, respectively. In 128 ureteral cancer patients, 60 patients (46.9%) had tumor in lower ureter, 27 patients (21.1%) in distal end of ureter, 26 patients (20.3%) in middle ureter, 12 patients (9.4%) in upper ureter and 3 patients (2.3%) in whole ureter. In combination of tumor location, 101 patients (41.2%) had tumor in only renal pelvis, 94 patients (38.4%) had in only ureter, 14 patients (5.7%) had in renal pelvis and ureter, 19 patients (7.8%) had in renal pelvis and bladder, 12 patients (4.9%) had in ureter and bladder, and 5 patients (2%) had in renal pelvis, ureter and bladder. Five year survival rate of renal pelvic cancer according to tumor location were 55.9% in upper calyx tumor, 60.8% in middle calyx tumor, 63.8% in lower calyx tumor, 60.2% in renal pelvic tumor and 63.8% in PUJ tumor, respectively. There were no significant difference between those 5 groups. Five years survival rate of ureteral cancer according to tumor location, 90% in upper ureteral tumor, 60.8% in middle ureteral tumor, 66.5% in lower ureteral tumor and 52.6% in tumor of distal end of ureter, respectively. Also in those 4 groups, there were no significant difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Epidemiology of syringomyelia in Japan--the nationwide survey].

The nationwide epidemiological survey of syringomyelia was carried out in Japan by sending inquiries to neurologists, child neurologists, neurosurgeons and orthopedic surgeons for the period of 1991 and 1992. A total of 1,243 cases of syringomyelia were ascertained. Among them, 622 were men and 619 women, and the average age of onset was 28 years old. The classification by Barnett et al was used, presenting syringomyelia with Chiari malformation in 684 cases (51.2%), dysraphism in 47 (3.7%), post traumatic syringomyelia in 139 (11%), post-spinal arachnoiditis in 76 (6%), spinal cord tumor in 132 (10.5%) and others in 204. Its predominant clinical course was slowly progressive, but 202 cases (17.9%) showed rather stable course including spontaneous resolution in 29 cases. The main initial symptoms were numbness in 522 cases (42%), motor disturbance in 504 (40.5%), and pain in 296 (23.8%). Neurologic signs noted in the abnormality of deep tendon reflexes in 836 cases (67.3%), motor disturbance in 763 (60.4%) and positive pathological reflexes in 383 (30.1%). Sensory disturbance was found in 942 cases (75.8%) and the dissociated type were 559 out of them (59.3%). It is noteworthy that 982 out of 1,243 were documented by MRI and surgical operations such as foramen magnum decompression, syringo-subarachnoid shunt and others were performed in 829 cases. Syringobulbia was confirmed on MRI in 101 cases of syringomyelia in which spinal cord tumors were most frequently associated.

Adolescent↗

Molecular cloning of cDNA for XTCAD-1, a novel Xenopus cadherin, and its expression in adult tissues and embryos of Xenopus laevis.

We have isolated from a Xenopus tailbud cDNA library a novel cadherin cDNA, denoted as XTCAD-1, which contained an open reading frame including the entire coding region. XTCAD-1 codes for 714 amino acids (molecular mass: 96 kDa), which include five characteristic extracellular cadherin motifs, a single putative transmembrane domain, and a cytoplasmic domain. In each domain, XTCAD-1 shared extensive homologies with other cadherins, and was related to EP-, E-, and P-cadherins more closely than to N- and M-cadherins. In adult Xenopus, XTCAD-1 mRNA was strongly expressed in intestine/stomach, kidney and skin, which are respectively derived from endoderm, mesoderm, and ectoderm. In Xenopus embryogenesis, expression of XTCAD-1 mRNA was first detected at blastula stage, and the level of the expression increased gradually during gastrula stage, reached a peak at tailbud stage and then decreased slightly at tadpole stage. These results suggest that in Xenopus laevis XTCAD-1 plays an important role in the maintenance of adult tissues that contain epithelial cells abundantly and also in morphogenesis in early embryonic development.

Amino Acid Sequence↗

A synthetic peptide deduced from the sequence in the cross-region of laminin A chain mediates neurite outgrowth, cell attachment and heparin binding.

Synthetic peptides from the cross-region of the laminin A chain were prepared and tested for their biological activities, especially for neurite outgrowth. A synthetic 8-mer peptide (designated LMA-5) in the cross-region of the laminin A chain was found to promote neurite outgrowth in PC12 cells and cerebellar microexplant cultures. Furthermore, this peptide mediated cell attachment and heparin binding. In addition, an antibody against peptide LMA-5 inhibited laminin- and LMA-5-mediated cell attachment. This antibody also inhibited more than half of the LMA-5-promoted neurite outgrowth in cerebellar microexplant cultures. These data suggest that peptide LMA-5 is one of the active sites in laminin that regulate cell behaviour including neurite outgrowth, cell attachment and heparin binding.

Amino Acid Sequence↗