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Biomedical subjects

S Kuroda

Publications and source records attributed to S Kuroda.

At least 73 records · Page 4Linked to original sources
PubMed2001

Lectin cytochemistry of rat cerebral and cerebellar neuronal cells.

Lectin cytochemistry of normal rat central nervous system (CNS) was performed on formalin-fixed, paraffin-embedded sections by using 14 lectins and light and electron microscopy. Hippocampal neurons reacted positively with Griffonia (Bandeiraea) simplicifolia lectin I (GSL-I), Griffonia (Bandeiraea) simplicifolia lectin II (GSL-II) and Vicia villosa agglutinin (VVA); neurons in the cornu ammonis (CA) 2 region reacted positively with GSL-I and GSL-II, and neurons in the CA2 and CA3 regions reacted with VVA. Cortical neurons reacted positively with GSL-I and VVA. Cerebellar Purkinje cells and granule cells were reactive with Phaseolus vulgaris leukoagglutinin (PHA-L). Cerebellar nucleus neurons were also reactive with PHA-L and VVA. Reactivity with GSL-I, GSL-II, VVA and PHA-L was observed only on the neuronal cell surface. The present findings demonstrate the differences between cerebral and cerebellar neurons in reacting with glycoconjugates.

Animals↗
PubMed2001

Repair of a fistula between the bladder and the perineal skin by femoral gracilis flap interposition.

The successful repair of a fistula between the bladder and the perineal skin using a femoral gracilis flap is reported. A 70-year-old woman, who 10 years previously had undergone a total hysterectomy for uterine cancer, developed a fistula between the bladder and the perineal skin after she underwent Mile's operation for rectal cancer. Initially, an attempt was made to repair the fistula by the transabdominal approach. This failed, probably because of the lack of supporting tissue between the bladder and the perineal skin. The second repair was performed with plastic surgeons. A secure three-layer bladder closure was accomplished. A right femoral gracilis flap was developed and rotated 180 degrees to fill the defect in the skin and subcutaneous tissue. Four weeks after surgery, cystography revealed no fistula or urinary leakage and the drainage catheter was removed. Femoral gracilis flap interposition was successful for repair of a fistula between the bladder and the perineal skin when there was no supporting tissue due to extensive exenteration in the surgical removal of rectal cancer and after other repair procedures had been unsuccessful.

Aged↗
PubMed2001

Two kinds of mitogen-activated protein kinase phosphatases, MKP-1 and MKP-3, are differentially activated by acute and chronic methamphetamine treatment in the rat brain.

Two functionally different MAP kinase phosphatases (MKPs) were investigated to clarify their roles in behavioral sensitization to methamphetamine (METH). MKP-1 mRNA levels increased substantially by about 60-300% in a range of brain regions, including several cortices, the striatum and thalamus 0.5-1 h after acute METH administration. After chronic METH administration its increase was less pronounced, but a more than 50% increase was still seen in the frontal cortex. MKP-1 protein levels also increased 3 h after acute or chronic METH administration. MKP-3 mRNA levels increased by about 30-50% in several cortices, the striatum and hippocampus 1 h after acute METH administration, but only in the hippocampus CA1 after chronic METH administration. Pre-treatment with the D(1) dopamine receptor antagonist, SCH23390, attenuated the METH-induced increase of MKP-1 and MKP-3 mRNA in every brain region, while pre-treatment with the NMDA receptor antagonist, MK-801, attenuated it in some regions. These findings suggest that in METH-induced sensitization, MKP-1 and MKP-3 play important roles in the neural plastic modification in widespread brain regions in the earlier induction process, but in the later maintenance process, they do so only in restricted brain regions such as MKP-1 in the frontal cortices and MKP-3 in the hippocampus.

Acute Disease↗
PubMed2001

Surgically-induced astigmatism following single-site phacotrabeculectomy, phacotrabeculotomy and advanced non-penetrating phacotrabeculectomy.

We study surgically-induced astigmatism following three kinds of glaucoma surgeries combined with cataract surgery with 6 months of follow-up. The mean surgically-induced astigmatism at 6 months postoperatively was 1.92 +/- 1.87 diopters in phacotrabeculectomy (n = 45), 0.72 +/- 0.40 diopters in advanced non-penetrating phacotrabeculectomy (n = 40) and 0.76 +/- 0.47 diopters in phacotrabeculotomy (n = 49), which appeared to be stabilized by 3 months. Each group revealed a tendency of "with the wound" induced astigmatism. Phacotrabeculectomy could induce greater surgically-induced astigmatism than advanced non-penetrating phacotrabeculectomy and phacotrabeculotomy.

Astigmatism↗
PubMed2001

Trabeculotomy combined with phacoemulsification and implantation of intraocular lens for primary open-angle glaucoma.

Retrospective study examined the surgical effects of lowering intraocular pressure of trabeculotomy combined with phacoemulsification and implantation of an intraocular lens. Included in the retrospective study were 96 eyes of 64 patients with primary open-angle glaucoma. Preoperative mean IOP was 25.6 mmHg. At final examination, the IOP was well-controlled at 21 mmHg or lower without medications in 32 of 96 eyes. In another 62 eyes, the IOP was well-controlled with antiglaucoma medications. The postoperative IOPs were in the high teens after surgery. The life table analysis using Kaplan-Meier methods showed that the success probability after phacoemulsification and implantation of intraocular lens, combined with trabeculotomy (PIT)-I and PIT-II, were 93.9% and 82.6% at 4 years, respectively. Postoperative visual acuity improved by more than two lines in 79 of the 96 eyes. In no case was the visual acuity decreased by more than two lines. Deterioration of the visual field was found in 4 eyes. There were no complications such as shallow anterior chamber, choroidal detachment, malignant glaucoma, hypotonic maculopathy, and endophthalmitis. This triple procedure should be performed in the early stages of glaucoma. Trabeculotomy is thought to relieve the resistance to aqueous outflow by mechanical cleavage of the trabecular meshwork and the inner layer of Schlemm's canal. This technique leads to aqueous outflow the from the opening of the internal trabecular meshwork to the collector channel. For this reason trabeculotomy was developed by a number of surgeons. Recently, however, trabeculotomy has not been selected for those patients with advanced stages of primary open-angle glaucoma because of the disadvantages such as transient intraocular pressure (IOP) elevation several days after surgery and somewhat higher levels (18 mmHg) of postoperative intraocular pressure (Fig. 1). To avoid the IOP spike (transient IOP elevation) after trabeculotomy, we reported previously that the new technique of trabeculotomy combined with outer sclerectomy was a useful surgical option. The results of our previous study indicated that the postoprative intraocular pressure levels after combined trabeculotomy and outer sclerectomy were significantly lower than that of trabeculotomy alone. On the other hand, trabeculotomy with mitomycin C is currently the standard filtration procedure for glaucoma. This technique, however causes severe postoperative complication such as hypotonic maculopathy, bleb leakage and late bleb infection. The major advantages of trabeculotomy preclude these severe complications resulting from creating progressive filtration of aqueous humor from the anterior chamber to the subconjunctival space. The recent advance of small-incision phacoemulsification procedure prompted phacoemulsification and implantation of intraocular lens and trabeculotomy. The theoretical advantages of smaller scleral, conjunctival incision, reduced stimuli to wound healing, and inflammation, could improve long-term IOP control in patients with glaucoma. Therefore several reports have been published on the surgical outcomes of combined trabeculotomy and modern phacoemulsification. These reports suggested that the combined trabeculotomy and a small-incision with intraocular lens implantation is effective in controlling IOP in patients with glaucoma.

Aged↗
PubMed2001

Trabeculectomy combined with phacoemulsification and intraocular lens implantation.

It has recently become popular to use mitomycin C (MMC) with trabeculectomy. MMC helps to maintain effective filtration and long-term intraocular pressure (IOP) control, while the use of laser suture lysis has improved the safety of this procedure. We evaluated the outcome of trabeculectomy alone and of trabeculectomy plus phacoemulsification (PEA) and intraocular lens (IOL) implantation, each supplemented with MMC. The mean preoperative IOP for the trabeculectomy alone group was 22.4 +/- 3.2 mmHg(bleb+), 25.3 +/- 2.6 mmHg(bleb-), and that of the combined surgery group was 22.4 +/- 2.8 mmHg(bleb+), 21.0 +/- 3.5 mmHg(bleb-). Mean postoperative IOP for the two groups were 13.3 +/- 2.7 mmHg(bleb+), 17.1 +/- 4.4 mmHg(bleb-) and 11.9 +/- 2.7 mmHg(bleb+), 16.4 +/- 3.4 mmHg(bleb-), respectively. After 4.5 years, the success probability for postoperative IOP control was 38%(bleb+), 3%(bleb-) in the trabeculectomy alone group and 53%(bleb+), 10%(bleb-) in the combined surgery group (<or=12 mmHg) and 65%(bleb+), 3%(bleb-) and 75%(bleb+), 10%(bleb-) (<or=14 mmHg)(Kaplan-Meier survival rate). With early complications, the frequency of shallow anterior chamber and choroidal detachment were significantly fewer in the combined surgery group. The combined surgery of PEA, IOL implantation and trabeculectomy is an effective procedure that offers visual rehabilitation, fewer early complications and good IOP control in patients with advanced, medically uncontrolled glaucoma and cataract.

Cataract↗
PubMed2001

Advanced nonpenetrating trabeculectomy (advanced NPT) and combined surgery of advanced NPT and phacoemulsification and intraocular lens implantation.

We have devised a new glaucoma surgery combining deep sclerectomy with nonpenetrating trabeculectomy (NPT); we call this surgery advanced NPT. We evaluated intraocular pressure (IOP) control, postoperative complication and visual acuity after combined advanced NPT and phacoemulsification and intraocular lens implantation (combined surgery), and advanced NPT alone. The mean preoperative IOP for the trabeculectomy only group was 22.4 +/- 6.3 mmHg(bleb+), 23.0 +/- 4.9 mmHg(bleb-), and that of the combined surgery group was 18.1 +/- 4.5 mmHg(bleb+), 18.5 +/- 2.6 mmHg(bleb-). Mean postoperative IOP for the two groups were 13.0 +/- 2.3 mmHg(bleb+), 15.0 +/- 1.5 mmHg(bleb-) and 12.9 +/- 2.7 mmHg(bleb+), 13.3 +/- 2.4 mmHg(bleb-), respectively. After 15 months, the success probability for postoperative IOP control were 63%(bleb+), 23%(bleb-) in the advanced NPT only group (<or=12 mmHg), and 60% in the advanced NPT only group, 70% in the combined surgery group (<or=14 mmHg) (Kaplan-Meier survival rate). In early complication, there were significantly fewer cases of shallow anterior chamber, hypertension, hypotension and anterior chamber inflamation in both groups than that of trabeculectomy. Nd:YAG goniopuncture was performed for purposes of better IOP control; preferred performance being within a month after surgery. Regarding visual acuity after either advanced NPT alone or combined surgery, an earlier recovery can be expected than with trabeculectomy. Advanced NPT and combined procedure is a reliable technique for glaucoma and cataract surgery.

Aged↗
PubMed2001

Influence of pH on the permeability of p-toluidine and aminopyrine through shed snake skin as a model membrane.

The influence of pH on the permeability of p-toluidine (pKa, 5.3) and aminopyrine (pKa, 5.0) through shed snake skin as a model membrane was studied. The pH was adjusted to several values, and the solubility of the drugs in each donor was measured. Flux rates and permeability coefficients were calculated from the steady-state penetration portions. The flux rates of p-toluidine decreased as the pH value in the donor solution increased. On the other hand, the flux rates of aminopyrine were constant at any pH value. The permeability coefficients of each drug increased as the pH value in the donor solution increased. The partition coefficients (octanol/buffer) of each drug were dependent on the molecular fraction of un-ionized species. From these results, it is suggested that ionized species of p-toluidine transports through shed snake skin, but the ionized species of aminopyrine does not.

Algorithms↗
PubMed2001

Effects of pranlukast, a leukotriene receptor antagonist, on airway inflammation in mild asthmatics.

To determine the anti-inflammatory actions of pranlukast, a cysteinyl leuklotriene receptor antagonist, we measured exhaled nitric oxide (NO) concentrations and eosinophil ratio in induced sputum of three groups of mild asthmatics (n = 30): treated with bronchodilators alone, with bronchodilators and inhaled steroid (beclomethasone dipropionate; 400 microg/day), and bronchodilators and pranlukast (450 mg/day). Pranlukast (450 mg/day) reduced the eosinophil ratio in the induced sputum significantly (p < 0.01) without a major effect on the concentration of exhaled NO. Pranlukast also increased values of peak expiratory flow significantly (p < 0.05). Pranlukast may be useful for mild asthmatics, in part through its ability to suppress eosinophilic airway infiltration.

Adult↗
PubMed2001

Effects of surgical revascularization on peripheral artery aneurysms in moyamoya disease: report of three cases.

OBJECTIVE AND IMPORTANCE: The beneficial effects of surgical revascularization on rebleeding in moyamoya disease remain unclear. This report is intended to clarify the effects of surgical revascularization on peripheral artery aneurysms, which represent one of the causes of intracranial bleeding in moyamoya disease. CLINICAL PRESENTATION: Findings for three female patients who experienced intracranial bleeding are presented. Cerebral angiography revealed that intracranial bleeding resulted from the rupture of peripheral artery aneurysms arising from dilated collateral vessels such as the lenticulostriate artery. INTERVENTION: The patients successfully underwent superficial temporal artery-middle cerebral artery anastomosis combined with encephaloduromyoarteriosynangiosis. Angiography demonstrated obliteration of the peripheral artery aneurysms, together with the disappearance or decrease in caliber of the parent collateral arteries, after surgery. None of the patients experienced rebleeding during the follow-up period (up to 52 mo). CONCLUSION: The results strongly suggest that surgical revascularization potentially improves cerebral circulation and decreases hemodynamic stress on collateral vessels, obliterating peripheral artery aneurysms.

Adult↗
PubMed2001

Involvement of IQGAP1, an effector of Rac1 and Cdc42 GTPases, in cell-cell dissociation during cell scattering.

We have previously proposed that IQGAP1, an effector of Rac1 and Cdc42, negatively regulates cadherin-mediated cell-cell adhesion by interacting with beta-catenin and by causing the dissociation of alpha-catenin from cadherin-beta-catenin-alpha-catenin complexes and that activated Rac1 and Cdc42 positively regulate cadherin-mediated cell-cell adhesion by inhibiting the interaction of IQGAP1 with beta-catenin. However, it remains to be clarified in which physiological processes the Rac1-Cdc42-IQGAP1 system is involved. We here examined whether the Rac1-IQGAP1 system is involved in the cell-cell dissociation of Madin-Darby canine kidney II cells during 12-O-tetradecanoylphorbol-13-acetate (TPA)- or hepatocyte growth factor (HGF)-induced cell scattering. By using enhanced green fluorescent protein (EGFP)-tagged alpha-catenin, we found that EGFP-alpha-catenin decreased prior to cell-cell dissociation during cell scattering. We also found that the Rac1-GTP level decreased after stimulation with TPA and that the Rac1-IQGAP1 complexes decreased, while the IQGAP1-beta-catenin complexes increased during action of TPA. Constitutively active Rac1 and IQGAP1 carboxyl terminus, a putative dominant-negative mutant of IQGAP1, inhibited the disappearance of alpha-catenin from sites of cell-cell contact induced by TPA. Taken together, these results indicate that alpha-catenin is delocalized from cell-cell contact sites prior to cell-cell dissociation induced by TPA or HGF and suggest that the Rac1-IQGAP1 system is involved in cell-cell dissociation through alpha-catenin relocalization.

Animals↗
PubMed2001

Long-term prognosis of medically treated patients with internal carotid or middle cerebral artery occlusion: can acetazolamide test predict it?

BACKGROUND AND PURPOSE: The importance of hemodynamic parameters for predicting outcome in patients with occlusive carotid disease remains controversial. The present study was aimed at testing the hypothesis that regional cerebrovascular reactivity (rCVR) to acetazolamide can be a reliable predictor of subsequent ischemic stroke in medically treated patients with internal carotid artery or middle cerebral artery occlusion. METHODS: Seventy-seven symptomatic patients were enrolled in this prospective, longitudinal cohort study. All patients met inclusion criteria of cerebral angiography, no or localized cerebral infarction on MRI or CT, and no or minimal neurological deficit. Regional cerebral blood flow (rCBF) and rCVR to acetazolamide were quantitatively determined by (133)Xe SEPCT. All patients were categorized into 4 types on the basis of SPECT studies. RESULTS: During an average follow-up period of 42.7 months, 16 total and 7 ipsilateral ischemic strokes occurred. The annual risks of total and ipsilateral stroke in patients with decreased rCBF and rCVR were 35.6% and 23.7%, respectively, risks that are higher than those in other types of patients. When strokes were categorized into patients with and without decreased rCBF and rCVR, Kaplan-Meier analysis revealed that the risks of total and ipsilateral stroke in patients with decreased rCBF and rCVR were significantly higher than in those without (P<0.0001 and P=0.0001, respectively, log-rank test). Relative risk conferred by decreased rCBF and rCVR was 8.0 (95% CI, 1.9 to 34.4) for ipsilateral stroke and 3.6 (95% CI, 1.4 to 9.3) for total stroke. CONCLUSIONS: Decreased rCBF and rCVR to acetazolamide may identify a subgroup of patients who have a higher risk of subsequent ischemic stroke when treated medically.

Acetazolamide↗
PubMed2001

Design, synthesis and biological evaluation of a novel series of potent, orally active adenosine A1 receptor antagonists with high blood-brain barrier permeability.

A novel series of 3-(2-substituted-3-oxo-2,3-dihydropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridines (5-38) were synthesized and evaluated for their in vitro adenosine A1 and A(2A) receptor binding activities, and in vitro metabolism by rat liver in order to search for orally active compounds. Most of the test compounds were potent adenosine A1 receptor antagonists with high A1 selectivity and the A1 affinity and A1 selectivity of carbonyl derivatives (5-11) was particularly high. In particular, compound 7 was an extremely potent and selective adenosine A1 antagonist with high A1 selectivity (Ki=0.026 nM, A(2A)/A1=5400). In terms of metabolic stability, 2-oxopropyl (5), 2-hydroxypropyl (12), N-methylacetamide (16), 2-(piperidin-1-yl)ethyl (28) and 1-methylpiperidin-4-yl (32, FR194921) were the most stable compounds in this series of analogues. Further in vivo evaluation indicated that compounds 5, 13, 17, 28 and 32 were detected in both plasma and brain after oral administration in rats. In particular, 32 displayed good plasma and brain concentrations (dose: 32 mg/kg (n=3); after 30 min, plasma conc.=3390+/-651nM, brain conc.=3670+/-496nM; after 60min, plasma conc.=1580+/-348nM, brain conc.=2143+/-434nM), and a good brain/plasma ratio (1.11+/-0.060 (30min), 1.39+/-0.172 (60min)). As a result, we could show that 32 is a good candidate for an orally active adenosine A1 receptor antagonist with high blood-brain barrier permeability and good bioavailability (Ki=6.6nM, A(2A)/A1=820, BA=60.6+/-4.9% (32 mg/kg)).

Administration, Oral↗
PubMed2001

Brain specific human genes, NELL1 and NELL2, are predominantly expressed in neuroblastoma and other embryonal neuroepithelial tumors.

NELL1 and NELL2 encode cysteine-rich amino acid sequences including six epidermal growth factor-like motifs, which contain signal peptides at the N-terminals. The deduced amino acid sequences of both genes are 55% identical and their cysteine stretch structures are conserved. NELL1 is expressed in the brain and kidney, whereas NELL2 is expressed specifically in the brain. The cell lineage expressing NELLs in the nervous system was investigated in established cell lines and central nervous system tumor tissues obtained from patients by Northern blot and reverse transcriptase-polymerase chain reaction analyses. NELL1 and NELL2 were predominantly expressed in neuroblastoma cell lines and little expressed in glioblastoma cell lines. NELL1 and NELL2 were also expressed in central neurocytoma, medulloblastoma, and some astrocytic tumors. Immunohistochemical analysis revealed that NELL2 protein was localized in the cytoplasm of neurons. These results suggest that NELL2 is predominantly expressed in the neuronal cell lineage in the human nervous system. NELL1 is expressed mainly in tumors in the neuronal cell lineage.

Aged↗
PubMed2001

[Preliminary results of PET activation study in cerebral arteriovenous malformation (AVM), using C15O2 and 18F-FDG].

The authors applied PET activation study to two patients with arteriovenous malformation (AVM) to localize primary motor cortex before surgery or embolization. The change in regional cerebral blood flow (rCBF) was measured during foot movements in Case 1 who had a 2-cm AVM located in the post-central gyrus. Superimposed PET/MRI images revealed that the rCBF increase was located in the pre-central gyrus. Its validity was confirmed by intraoperative cortical mapping using electrical median nerve stimulation. The patient safely underwent total removal of AVM. The change in regional cerebral metabolic rate for glucose (rCMRglc) was measured during hand movements in Case 2 who had a huge AVM over the central sulcus. Superimposed PET/MRI images revealed that hand movements significantly increased rCMRglc in the frontal cortex, which was separated from the original primary motor area. The patient safely underwent partial embolization, although he suffered transient weakness of the face after embolization. The preliminary results strongly suggest that PET activation study is useful to localize precisely cortical functions of the patients with AVM, thus reducing morbidity after treatment. The results also suggest that cortical functions may undergo translocation when huge AVM involves the eloquent area.

Activation Analysis↗
PubMed2001

Cerebral revascularization for moyamoya disease in children.

Ninety-four patients with moyamoya disease (56 in the pediatric age group and 38 adults) were treated by revascularization surgery in the past 21 years (1979--2000). Combined surgery of the superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis and indirect revascularization of encaphalo-duro-arterio-myo-synangiosis (EDAMS) was performed. Ischemic attacks disappeared in most patients within 1 year (mean) after surgery in pediatric cases. No morbidity or mortality was experienced in the pediatric group. Some children with cerebral infarction before the surgery, however, had mild mental retardation even after the surgery. Early diagnosis and proper prophylactic surgical treatment is indispensable for pediatric patients with moyamoya. MR angiography is an important diagnostic modality for the screening and longitudinal follow-up of moyamoya disease.

Brain↗
PubMed2001

[Diagnosis of cerebral aneurysm using 3-dimensional digital subtraction angiography].

Recent rapid advancement in the technology of magnetic resonance angiography and 3-dimensional computed tomography angiography has opened the door to a less-invasive diagnostic routine for the treatment of cerebral aneurysms. However, from the viewpoint of decision making concerning which treatment to use; conservative therapy; surgical intervention; or endovascular treatment, much more precise information is necessary. Recent progress of rotation digital subtraction angiography has introduced 3-dimensional digital subtraction angiography. In the past year, 28 cases involving 39 aneurysms have been studied using 3-dimensional angiography. This study was carried out, using a rotating C-arm, which rotates 220 degrees in 5.8 seconds. All raw data gathered was transferred to the workstation for image reconstruction. The purpose of this study was to evaluate the clinical potential of 3-dimensional digital subtraction angiography for the diagnosis of the cerebral aneurysms.

Angiography, Digital Subtraction↗