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S Shibuya

Publications and source records attributed to S Shibuya.

At least 37 records · Page 2Linked to original sources

[A case of polyneuropathy associated with increased levels of vascular endotherial growth factor (VEGF) insera].

A 54-year-old woman began to notice numbness and motor weakness in the lower extremities in July 1999. These symptoms rapidly progressed and she could not walk any more. When she admitted to our hospital, she showed peripherally dominant, moderate motor weakness, drop foot and loss of superficial and deep sensation in the lower extremities, but only slight weakness in the hands. Cranial nerves were intact. Deep tendon reflexes were all absent. Nerve conduction velocities were reduced and cerebrospinal fluid protein was elevated. VEGF was greatly increased in serum (1,850 pg/ml), which has been found to be increased exclusively in patients with Crow-Fukase syndrome. Many characteristic manifestations of the syndrome except polyneuropathy are well explained to be resulted from the abnormal production of VEGF. She did not, however, exhibit any constellation of Crow-Fukase syndrome such as edema, skin change, organomegaly, bone lesions or M-proteinemia. Steroid therapy improved her symptoms and lessened the levels of serum VEGF and cerebrospinal fluid protein. This case indicated that overproduction of VEGF could induce polyneuropathy rather than the other symptoms of Crow-Fukase syndrome, and that a polyneuropathy associated with increased VEGF might exist.

Endothelial Growth Factors↗

Aquaporin 4: lack of mRNA expression in the rat regenerating muscle fiber under denervation.

The recently identified water channel aquaporin 4 is a major component of the orthogonal arrays observed with freeze-fracture electron microscopy. We examined the expression of aquaporin 4 mRNA and protein in rat regenerating muscle under innervated and denervated conditions. We found decreased sarcolemmal immunostaining of aquaporin 4 in denervated regenerating muscle as opposed to innervated muscle. Quantitative reverse transcription-polymerase chain reaction revealed that aquaporin 4 mRNA was expressed in the innervated regenerating muscle; whereas it was not expressed in denervated muscle. Thus, lack of aquaporin 4 protein may be due to lack of aquaporin 4 mRNA in the denervated regenerating muscle. We conclude that the nerve supply influences expression of aquaporin 4 at the mRNA level in regenerating muscle.

Animals↗

Aciculin and its relation to dystrophin: immunocytochemical studies in human normal and Duchenne dystrophy quadriceps muscles.

Aciculin is a novel adherens junction antigen extracted from human uterine smooth muscle that is reported to associate biochemically with dystrophin. We attempted to determine (i) the immunostainability of anti-aciculin antibody for the 6 histochemically normal human muscles and seven muscles from boys with Duchenne muscular dystrophy (DMD) and 11 disease control muscles, (ii) the ultrastructural localization of aciculin in normal skeletal myofibers, (iii) aciculin's spacial relationship with dystrophin and beta-spectrin, and (iv) if the aciculin is ultrastructurally colocalized with dystrophin, the distance from the aciculin epitope to the epitope of the dystrophin N- or C-terminal domain. For this, rabbit anti-aciculin antibody was generated against the synthetic peptide of aciculin fragment D [4]. Immunohistochemical staining showed that the immunostainability of DMD muscles for anti-aciculin antibody was markedly decreased as compared with normal and disease control muscles. Single and double immunogold labeling electron microscopy of 6 histochemically normal human quadriceps femoris muscles revealed that aciculin was present along the inner surface of muscle plasma membrane and that aciculin formed doublets more frequently with dystrophin (23.5 +/- 1.8%; group mean +/- SE) than with beta-spectrin (12.8 +/- 1.1%; P < 0.01 two tailed t test). Rabbit anti-aciculin antibody frequently formed doublets with monoclonal antibodies against the N- or C-terminal domain of dystrophin at the muscle cell surface. These results suggest that aciculin is associated with dystrophin and may interact with both the N- and C-terminal domains of dystrophin.

Child↗

Synthesis and evaluation of multisubstrate analogue inhibitors of purine nucleoside phosphorylases.

1,1-Difluoro-2-(tetrahydro-3-furanyl)ethylphosphonic acids (+/-)-cis-4a and (+/-)-trans-4a possessing a (purine-9-yl)methyl functionality at the ring as well as their homologues (+/-)-cis-4b and (+/-)-trans-4b were synthesized and tested as 'multi-substrate analogue' inhibitors for purine nucleoside phosphorylases. Radical cyclization of allylic alpha,alpha-difluorophosphonates 8a,b was applied to construct the alpha,alpha-difluorophosphonate-functionalized oxacycles 9a,b. The IC50 values of the nucleotide analogues (+/-)-cis-4a and (+/-)-cis-4b were 88 and 38 nM, respectively, for human erythrocyte PNP-catalyzed phosphorylation of inosine in the presence of 100mM orthophosphate. The stereochemistry of the inhibitors was found to affect significantly the inhibitory potency. The transisomers (+/-)-trans-4a and (+/-)-trans-4b were ca. 4-fold less potent than the corresponding cis-isomers. At an intracellular concentration of orthophosphate (1 mM), (+/-)-cis-4b, the most potent compound of this series, was shown to have IC50 and Ki values of 8.7 and 3.5 nM, respectively.

Enzyme Inhibitors↗

Blood supply routes of recurrent esophageal varices following endoscopic embolization.

BACKGROUND/AIM: The blood supply routes of recurrent esophageal varices following complete endoscopic embolization (EE) are not yet known. The purpose of this study is to identify these blood supply routes by comparing endoscopic varicography and percutaneous transhepatic portography (PTP). METHODS: Eleven cases of recurrent esophageal varices following EE are included in this study. The blood supply routes of primary and recurrent varices were analyzed by comparing the varicography obtained at the initial and repeat EE with PTPs before and after the initial EE. RESULTS: Endoscopic varicography at the time of initial EE could show the vessels of the left gastric vein (LGV) system, such as the cardiac branch of the LGV, and the cardiac venous plexus (CP) in 100% of cases, and the trunk of the LGV in 73% (8/11) of cases, whereas the posterior gastric vein was seen in only 18% (2/11) of cases. PTP performed 2 weeks after the initial EE confirmed that the routes visualized by endoscopic varicography could be obliterated in 10 of 11 cases. The blood supply routes of recurrent varices, demonstrated by varicography, were the vessels of the short gastric vein (SGV) system, such as the fundic branch of the SGV or the posterior gastric vein in 82% (9/11) of cases, and the partially reformed fine CP in 27% (3/11) of cases. Varicography revealed the remnant vessels of the LGV in only 1 case. CONCLUSIONS: The primary esophageal varices are supplied with blood mainly from the cardiac branch of the LGV through the CP. However, the blood supplies of recurrent varices following EE come from the fundic branch of the SGV or the posterior gastric vein. We conclude that three-dimensional obliteration of esophageal varices and their feeders, the LGV and SGV systems, is completed by initial and repeat EEs.

Adult↗

Urgent transjugular retrograde obliteration for prophylaxis of rebleeding from gastric varices in patients with a spontaneous portosplenorenal shunt.

BACKGROUND: Bleeding isolated gastric varices with a spontaneous portosplenorenal shunt are difficult to control. The urgent use of transjugular retrograde obliteration (TJO) to prevent early rebleeding and to improve early mortality has not yet been demonstrated. We report our experience with this technique in patients with isolated gastric varices after treatment of acute bleeding. METHODS: We reviewed our experience of 6 patients with isolated gastric varices with a spontaneous portosplenoral shunt treated with TJO after treatment of acute bleeding. We basically applied endoscopic glue embolization using cyanoacrylate monomer for treatment of acute bleeding. TJO was a method using an occlusive balloon catheter to control a spontaneous portosplenorenal shunt flow while injecting sclerosant retrograde into the gastric varices. RESULTS: Treatment of acute bleeding was achieved immediately by endoscopic glue embolization, endoscopic variceal ligation, and ligating the varices with sutures following anterior gastrotomy in 4, 1 and 1 patients, respectively, and then TJO was performed. Permanent hemostasis and variceal eradication was achieved in these 6, and they all survived. They were alive for 6-66 months without gastric variceal recurrence. CONCLUSIONS: We conclude that urgent TJO is effective in the prophylaxis of early and late rebleeding from isolated gastric varices in patients with a spontaneous portosplenorenal shunt.

Adult↗

Short-term hemodynamic effects of transjugular retrograde obliteration of gastric varices with gastrorenal shunt.

OBJECTIVES: The purpose of this study was to investigate the short-term effects on portal hemodynamics of transjugular retrograde obliteration (TJO) of gastric varices with gastrorenal shunt. METHODS: Thirty patients with gastric varices and a gastrorenal shunt were included in this study. The patients ranged in age from 42 to 75 years (16 men and 14 women), and according to Child's classification, class A, B and C cirrhosis was seen in 1, 13 and 16 patients, respectively. The portal blood flow was measured by an ultrasonic duplex Doppler system, and the wedged hepatic venous pressure was measured by hepatic venous catheterization, before and after TJO. RESULTS: Complete obliteration of the gastrorenal shunt and gastric varices was revealed by retrograde inferior phrenic venography and computed tomography after TJO in all cases. The wedged hepatic venous pressure was significantly increased the day after TJO compared with that before therapy (257 +/- 71 vs. 307 +/- 73 mm H(2)O, p < 0.01). The portal venous flow was significantly increased 1 week after TJO compared with that before therapy (744 +/- 190 vs. 946 +/- 166 ml/min, p < 0.01). The serum albumin levels before and after TJO were 3.0 +/- 0.4 and 3.1 +/- 0.5 g/dl, respectively, and the total bilirubin levels were 1.5 +/- 0.7 and 1. 5 +/- 0.8 mg/dl, respectively, neither of these parameters changing significantly. The plasma ammonia levels before and after TJO were 109 +/- 62 and 67 +/- 31 microg/dl, and the indocyanine green retention rates at 15 min were 31 +/- 13 and 24 +/- 13%, both showing a significant change (p < 0.01 and p < 0.05, respectively). CONCLUSIONS: We conclude that TJO increases portal blood flow which contributes to the decrease in plasma ammonia levels and the indocyanine green retention rate, although increasing the wedged hepatic venous pressure.

Adult↗

Short-term portal hemodynamic effects of endoscopic embolization for esophageal varices.

BACKGROUND/AIM: Endoscopic embolization (EE) is a specialized treatment that obliterates esophageal varices along with their associated blood supply. The purpose of this study was to investigate the short-term effects of EE for esophageal varices on portal hemodynamics and liver function. METHODS: Thirty patients with esophageal varices were included in this study. The portal blood flow was measured by an ultrasonic duplex Doppler system before and after EE. EE was performed by freehand intravariceal injection of 5% ethanolamine oleate with iopamidol with the aid of a balloon attached to the tip of an endoscope under fluoroscopy. RESULTS: For the blood supply system, endoscopic varicography at the time of EE was able to show the vessels of the cardiac branch of the left gastric vein in 93% of the cases, the cardiac venous plexus in 90%, the trunk of the left gastric vein in 27%, the lesser curvature branch of the left gastric vein in 10%, the fundic branch of the short gastric vein in 13%, and the posterior gastric vein in 13%. For the blood drainage system, endoscopic varicography was able to show the paraesophageal vein in 39% of the cases, the inferior phrenic vein in 17%, and the mediastinal vein in 13%. No clotting was detected after EE in the intra- and extraportal veins in any of the cases. The flow velocities in the main portal vein before and after EE were 14.2+/-3.2 and 15.5+/-3.5 cm/s, respectively, showing no significant change. The cross-sectional area of the portal vein before and after EE was 0.96+/-0.21 and 1.04+/-0.23 cm(2), and the flow volume of the portal vein was 817+/-288 and 930+/-189 ml/min, both also showing no significant change. The blood laboratory parameters showed no significant change after EE. CONCLUSIONS: We conclude that neither portal blood flow nor liver function were damaged by EE, although both the varices and their associated blood supply were obliterated.

Aged↗

[Respiratory function impairment in patients with Parkinson's disease--a consideration on the possible pathogenetic relation to autonomic dysfunction].

To investigate the characteristics and clinical significance of respiratory function in patients with Parkinson's disease (PD), we studied 38 patients (male, 19; female, 19: mean age, 65.5 years: mean duration of disease, 6.7 years) who had no history of respiratory disease and smoking. Fifty three non-respiratory disease subjects (male, 26; female, 27: mean age, 67.6 years) were served as age-matched control. We measured spirometry and maximal expiratory flow-volume curve in all patients, and analyzed the relations between respiratory function variables and clinical profiles. The clinical disability of PD was indicated by Hoehn-Yahr (H-Y) scale. The number of PD patients was 15 in H-Y 2, 18 in H-Y 3 and 5 in H-Y 4, respectively. The values of % VC, %FEV 1, FEV 1/FVC, %PEFR, % V50 in H-Y 4 group were significantly smaller than those in H-Y 2 and 3 groups. Small airway dysfunction (SAD) was represented by abnormality of % V25, % V50/V25. The prevalence of impairment in % V25 and % V50/V25 was detected in 13 patients (34.2%) and 15 patients (39.5%), respectively, this was significantly higher than age-matched controls. However, the mean value and prevalence of impairment in % V25, % V50/V25 were not affected by H-Y scale and duration of disease or ideal body weight (%predicted value). Twenty seven patients showed normal ventilatory function based on % VC over 80% and FEV 1/FVC over 70%. The prevalence of impairment in % V25, % V50/V25 was detected in 8 patients (29.6%), 9 patients (33.3%), respectively, among 27 patients with normal ventilatory function. These results suggest that ventilatory dysfunction is concerned with clinical disability but SAD which is independent of clinical disability seen prevalently in patients with PD. It is widely accepted that patients with PD frequently have cardiac or bowel dysfunction based on the visceral autonomic dysfunction. We hypothesize that SAD may also be caused by possible autonomic dysfunction in patients with PD.

Aged↗

Synthesis and biological evaluation of 1,1-difluoro-2-(tetrahydro-3-furanyl)ethylphosphonic acids possessing a N9-purinylmethyl functional group at the ring. a new class of inhibitors for purine nucleoside phosphorylases.

1,1-Difluoro-2-(tetrahydro-3-furanyl)ethylphosphonic acids cis-3 and trans-3 possessing a N9-purinylmethyl functionality at the ring were synthesized and tested as "multi-substrate analogue" inhibitors for purine nucleoside phosphorylases. Radical cyclization of allyic alpha,alpha-difluorophosphonate (E)-7 was applied to construct the alpha,alpha-difluorophosphonate-functionalized tetrahydrofuranyl moiety. The IC50 values of cis-3 and trans-3 for human erythrocyte PNP-catalyzed phosphorylation of inosine were determined to be 88 and 320 nM, respectively. The stereochemistry of the inhibitors was found to affect significantly the inhibitory potency.

Antineoplastic Agents↗

Immunocytochemical studies of aquaporin 4 in the skeletal muscle of mdx mouse.

Immunostainability of anti aquaporin 4 antiserum was investigated in the muscles of dystrophin deficient mdx mice. Western blot analysis showed that the rabbit antiserum against aquaporin 4 reacted with a 28 kDa protein in extracts of normal mouse quadriceps femoris muscles but did not react with the protein in extracts of quadriceps femoris muscles of mdx mice. Immunoperoxidase staining of the muscles from normal and mdx mice revealed the positive immunoreaction at the myofiber surface of normal mice and the negative, or the faint and discontinuous immunostaining at the surface of mdx myofibers. Immunogold electron microscopy disclosed the localization of aquaporin 4 molecules at the myofiber plasma membranes of normal mice and the localization was consistent with that of orthogonal array particles in the protoplasmic face of normal muscle plasma membrane seen in freeze fracture replicas. This study demonstrated that the density of aquaporin 4 molecules was decreased in the muscle plasma membranes of mdx mice, resulting in the faulty function of mdx myofibers.

Animals↗

Synthesis and biological evaluation of alpha,alpha-difluorobenzylphosphonic acid derivatives as small molecular inhibitors of protein-tyrosine phosphatase 1B.

A series of alpha,alpha-difluorobenzylphosphonic acids having a hydrophobic functional group were prepared via the Stille coupling reaction from halogenated alpha,alpha-difluorobenzylphosphonates. Evaluation of inhibitory activity toward protein tyrosine phosphatase (PTP 1B) revealed that the ethynyl, phenylethynyl and (E)-styryl groups on the benzene nuclei increased the inhibitory activity of alpha,alpha-difluorobenzylphosphonic acid. Inhibitory activities significantly increased upon introducing both (E)-styryl and bis-methylsulfonamide functional groups onto the benzene nuclei of alpha,alpha-difluorobenzylphosphonic acid.

Enzyme Inhibitors↗

Ultrastructural localization of alpha-, beta- and gamma-sarcoglycan and their mutual relation, and their relation to dystrophin, beta-dystroglycan and beta-spectrin in normal skeletal myofiber.

Ultrastructural localization of alpha-, beta- and gamma-sarcoglycan and their mutual relation, and their relation to dystrophin, beta-dystroglycan and beta-spectrin were investigated in normal skeletal myofibers. Single-immunogold labeling electron microscopy showed that the signals of rabbit and sheep polyclonal antibodies against the synthetic peptide of the cytoplasmic domain of alpha-, beta or gamma-sarcoglycan were present along the inside surface of muscle plasma membrane and at the sarcoplasmic side of plasma membrane invaginations and vesicular structures in subsarcolemmal areas. These localizations were similar to that of dystrophin, beta-dystroglycan and beta-spectrin. Double-immunogold labeling disclosed the close association of alpha-, beta- and gamma-sarcoglycan each other and alpha-, beta-, gamma-sarcoglycan with dystrophin or beta-dystroglycan, and this was confirmed by statistical analysis. Monoclonal antibody against the extracellular domain of alpha-sarcoglycan was used with above-mentioned polyclonal anti-beta- and -gamma-sarcoglycan antibodies for triple-immunogold labeling, in which signals of alpha-sarcoglycan localized at the outer surface of muscle plasmalemma and those of beta- and gamma-sarcoglycans were present at the inside surface of plasma membrane. The triple immunolabeling showed an occasional closely associated presence of the three signals for alpha-, beta-and gamma-sarcoglycans, and a more frequent association for two signals out of alpha-, beta- and gamma-sarcoglycans. This study demonstrated that alpha-, beta- and gamma-sarcoglycan are closely located to one another and to dystrophin and beta-dystroglycan at the muscle plasma membrane.

Animals↗

Meniscus transplantation using a cryopreserved allograft. Histological and ultrastructural study of the transplanted meniscus.

We performed allogenic meniscus transplantation in rabbits and investigated the regenerative process in the transplanted meniscus with particular respect to its ultra-structure. Under a transmission electron microscope, the chondrocytes and extracellular matrix were degenerated or destroyed in week 0. Fibroblasts were observed 4-8 weeks postoperatively. Immature chondrocytes emerged at 12 postoperative weeks. At 16 weeks, the newly formed chondrocytes and extracellular matrix were virtually normal. Although the diameter of collagen fibrils still varied, their arrangement was dense and the filaments had almost normal banding. This study demonstrated that newly formed chondrocytes may differentiate from fibroblasts 8-12 weeks after transplantation. The fibroblasts synthesized collagen fiber and glycosaminoglycan, indicating that repair of the extracellular matrix may be initiated 4-8 weeks postoperatively, becoming were active after 12 weeks when the newly formed chondrocytes emerge. The extracellular matrix is injured during rapid freezing, cryopreservation, and slow thawing, and repair is delayed due to this deterioration. The extracellular matrix thus needs to be protected from injury as far as possible in order to promote its repair, since it normalizes more slowly than chondrocytes.

Animals↗

Interaction of aluminum with PHFtau in Alzheimer's disease neurofibrillary degeneration evidenced by desferrioxamine-assisted chelating autoclave method.

To demonstrate that aluminum III (Al) interacts with PHFtau in neurofibrillary degeneration (NFD) of Alzheimer's disease (AD) brain, we developed a "chelating autoclave method" that allows Al chelation by using trivalent-cationic chelator desferrioxamine. Its application to AD brain sections before Morin histochemistry for Al attenuated the positive fluorescence of neurofibrillary tangles, indicating Al removal from them. This method, applied for immunostaining with phosphorylation-dependent anti-tau antibodies, significantly enhanced the PHFtau immunoreactivity of the NFD. These results suggest that each of the phosphorylated epitopes in PHFtau are partially masked by Al binding. Incubation of AD sections with AlCl(3) before Morin staining revealed Al accumulation with association to neurofibrillary tangles. Such incubation before immunostaining with the phosphorylation-dependent anti-tau antibodies abolished the immunolabeling of the NFD and this abolition was reversed by the Al chelation. These findings indicate cumulative Al binding to and thereby antigenic masking of the phosphorylated epitopes of PHFtau. Al binding was further documented for electrophoretically-resolved PHFtau on immunoblots, indicating direct Al binding to PHFtau. In vitro aggregation by AlCl(3) was observed for PHFtau but was lost on dephosphorylation of PHFtau. Taken together, phosphorylation-dependent and direct PHFtau-Al interaction occurs in the NFD of the AD brain.

Aluminum↗

Synthesis of novel nucleotide analogues possessing a difluoromethylenephosphonato group. Evaluation of the inhibitory activity for purine nucleoside phosphorylase.

Novel nucleotide analogues 1-6 were prepared as "multi-substrate" analogue inhibitors for purine nucleoside phosphorylases (PNPs). The cyclopropane and the tetrahydrofuran moieties of the alkyl spacer connecting a nucleobase and difluoromethylene phosphonic acid were found to be effective for good inhibition of PNPs.

Actinomycetales↗