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1.
World Neurosurg ; 181: e678-e684, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37898263

ABSTRACT

BACKGROUND: Vasospasm following an aneurysmal subarachnoid hemorrhage (SAH) causes serious neurological complications, despite surgical clipping of the aneurysm. Intrathecal urokinase (UK) infusion has been shown to effectively prevent symptomatic vasospasm in patients who have undergone endovascular obliteration of the ruptured aneurysms. OBJECTIVE: To investigate whether intrathecal UK infusion can prevent symptomatic vasospasm in patients undergoing surgical or endovascular treatment. METHODS: A total of 90 patients with severe aneurysmal SAH were enrolled and assigned to a surgical neck clipping (n = 56) or an endovascular coil embolization (n = 34) groups. After treatment, UK infusion from the lumbar drain was repeated in 32 patients in the surgical neck clipping group (group B) and all in the endovascular coil embolization group (group C) until complete resolution of the SAH was observed on computed tomography. The remaining 24 of the surgical neck clipping group, without UK infusion, were assigned to group A. RESULTS: Symptomatic vasospasm occurred in 7 (29.2%) patients in group A, 2 (6.3%) in group B, and none in group C (group A vs. group B [P = 0.02]; group B vs. group C [P = 0.14]). Excellent clinical outcomes (modified Rankin score, 0 or 1) were observed in 37.5%, 59.4%, and 76.5% of patients in group A, B, and C, respectively (group A vs. group B [P = 0.11]). CONCLUSION: Clearance of SAH via intrathecal UK infusion significantly reduced symptomatic vasospasm in patients in both UK groups, resulting in better clinical outcomes.


Subject(s)
Aneurysm, Ruptured , Intracranial Aneurysm , Subarachnoid Hemorrhage , Vasospasm, Intracranial , Humans , Subarachnoid Hemorrhage/complications , Subarachnoid Hemorrhage/surgery , Urokinase-Type Plasminogen Activator/therapeutic use , Vasospasm, Intracranial/drug therapy , Vasospasm, Intracranial/etiology , Vasospasm, Intracranial/prevention & control , Treatment Outcome , Tomography, X-Ray Computed/adverse effects , Aneurysm, Ruptured/complications , Aneurysm, Ruptured/surgery , Intracranial Aneurysm/complications , Intracranial Aneurysm/surgery
2.
Bioorg Med Chem Lett ; 41: 128011, 2021 06 01.
Article in English | MEDLINE | ID: mdl-33811993

ABSTRACT

Photodegradation of azilsartan produces a phenanthridine derivative, with its molecular structure determined by 1H and 13C NMR spectroscopy. This structure is confirmed by single-crystal X-ray diffraction and alternative synthesis. The phenanthridine ring formation is explained through the ring closure of an imidoylnitrene intermediate produced by decarboxylation of the 5-oxo-1,2,4-oxadiazole ring (oxadiazolone).


Subject(s)
Benzimidazoles/chemistry , Oxadiazoles/chemistry , Crystallography, X-Ray , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Structure , Phenanthridines/chemical synthesis , Phenanthridines/chemistry , Photochemical Processes
3.
Bioorg Med Chem ; 21(13): 3934-48, 2013 Jul 01.
Article in English | MEDLINE | ID: mdl-23651509

ABSTRACT

Here, a series of C-glucosides with azulene rings in the aglycon moiety was synthesized and the inhibitory activities toward hSGLT1 and hSGLT2 were evaluated. Starting from the azulene derivative 7 which had relatively good SGLT2 inhibitory activity, compound 8a which has a 3-[(azulen-2-yl)methyl]phenyl group was identified as a lead compound for further optimization. Introduction of a phenolic hydroxyl group onto the central benzene ring afforded a potent and selective SGLT2 inhibitor 8e, which reduced blood glucose levels in a dose-dependent manner in rodent diabetic models. A mono choline salt of 8e (YM543) was selected as a clinical candidate for use in treating type 2 diabetes mellitus.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Glucosides/chemistry , Glucosides/therapeutic use , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/therapeutic use , Sodium-Glucose Transporter 2 Inhibitors , Animals , Azulenes/chemistry , Azulenes/therapeutic use , Blood Glucose/analysis , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/metabolism , Male , Mice , Rats , Rats, Sprague-Dawley , Sodium-Glucose Transporter 2/metabolism
4.
Bioorg Med Chem ; 20(10): 3263-79, 2012 May 15.
Article in English | MEDLINE | ID: mdl-22507206

ABSTRACT

A series of C-glucosides with various heteroaromatics has been synthesized and its inhibitory activity toward SGLTs was evaluated. Upon screening several compounds, the benzothiophene derivative (14a) was found to have potent inhibitory activity against SGLT2 and good selectivity versus SGLT1. Through further optimization of 14a, a novel benzothiophene derivative (14h; ipragliflozin, ASP1941) was discovered as a highly potent and selective SGLT2 inhibitor that reduced blood glucose levels in a dose-dependent manner in diabetic models KK-A(y) mice and STZ rats.


Subject(s)
Blood Glucose/drug effects , Glucosides/chemistry , Glucosides/pharmacology , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/pharmacology , Sodium-Glucose Transporter 2 Inhibitors , Thiophenes/chemistry , Thiophenes/pharmacology , Animals , CHO Cells , Cricetinae , Diabetes Mellitus, Type 2 , Disease Models, Animal , Dose-Response Relationship, Drug , Glucosides/chemical synthesis , Glucosides/pharmacokinetics , Humans , Hypoglycemic Agents/chemical synthesis , Hypoglycemic Agents/pharmacokinetics , Inhibitory Concentration 50 , Male , Mice , Molecular Structure , Rats , Rats, Sprague-Dawley , Thiophenes/chemical synthesis , Thiophenes/pharmacokinetics
5.
Appl Opt ; 50(30): 5834-41, 2011 Oct 20.
Article in English | MEDLINE | ID: mdl-22015412

ABSTRACT

A technique to study the drying of paints, based on phase-shifting digital holography, is presented. The technique is applied to the drying process of solvent-based paint on a three-dimensional surface at different substrate temperatures. For processing the data, a cross-correlation function and phase change derived from reconstructed complex amplitudes are calculated to visualize and to evaluate the local variations in the dryness of paint. The relationship between the optical signal obtained by the holographic method and the actual microscopic variations occurring in the paint film is also investigated using the gravimetric technique and a microscope. It is shown that the holographic technique can determine the stationary state of a painted surface corresponding to the end of the falling rate period in the drying process. The holographic technique detects mainly the activity on the surface and is applicable to assessment of the early drying process of paint.

6.
Appl Opt ; 50(21): 3937-46, 2011 Jul 20.
Article in English | MEDLINE | ID: mdl-21772377

ABSTRACT

Phase-shifting digital holography is applied to the measurement of the surface profile of the inner surface of a pipe for the detection of a hole in its wall. For surface contouring of the inner wall, a two-wavelength method involving an injection-current-induced wavelength change of a laser diode is used. To illuminate and obtain information on the inner surface, a cone-shaped mirror is set inside the pipe and moved along in a longitudinal direction. The distribution of a calculated optical path length in an experimental alignment is used to compensate for the distortion due to the misalignment of the mirror in the pipe. Using the proposed method, two pieces of metal sheet pasted on the inner wall of the pipe and a hole in the wall are detected. This shows that the three-dimensional profile of a metal plate on the inner wall of a pipe can be measured using simple image processing.

7.
Appl Opt ; 47(34): 6325-33, 2008 Dec 01.
Article in English | MEDLINE | ID: mdl-19037358

ABSTRACT

An optical system of off-axis digital holography for imaging the Jones vector of an object wave is improved, and a Faraday rotator for the reference wave is also newly constructed. To evaluate the accuracy of the polarization analysis, quarter- and half-wave plates are used as the object, and the distribution of the polarization state of the transmitted light is analyzed for various orientations of the wave plates. The polarization analysis is also simulated, and the effect of a finite value of the extinction ratio and the modulation error for the reference wave is investigated numerically.

8.
Rev Sci Instrum ; 79(5): 056105, 2008 May.
Article in English | MEDLINE | ID: mdl-18513098

ABSTRACT

A prototype instrument for measuring astronaut body mass under microgravity conditions has been developed and its performance was evaluated by parabolic flight tests. The instrument, which is the space scale, is applied as follows. Connect the subject astronaut to the space scale with a rubber cord. Use a force transducer to measure the force acting on the subject and an optical interferometer to measure the velocity of the subject. The subject's mass is calculated as the impulse divided by the velocity change, i.e., M=integral Fdt/delta v. Parabolic flight by using a jet aircraft produces a zero-gravity condition lasting approximately 20 s. The performance of the prototype space scale was evaluated during such a flight by measuring the mass of a sample object.


Subject(s)
Body Weight , Body Weights and Measures/instrumentation , Weightlessness , Astronauts , Body Weights and Measures/methods , Humans , Space Flight/instrumentation
9.
Appl Opt ; 45(29): 7610-6, 2006 Oct 10.
Article in English | MEDLINE | ID: mdl-17068593

ABSTRACT

Surface contouring by phase-shifting digital holography is proposed and verified by experiments and numerical simulations. Digital holograms are recorded before and after mode hopping of a laser diode subject to current tuning, and the difference of the reconstructed phases at each wavelength is computed to deliver surface contours of a diffusely reflecting surface. Since normal incidence on the object is employed, the method does not need the removal of the tilt component and is free from the shadowing effect as advantages over the dual-incidence method proposed before by the first author.

10.
Chem Pharm Bull (Tokyo) ; 54(5): 706-10, 2006 May.
Article in English | MEDLINE | ID: mdl-16651773

ABSTRACT

Regioselective alkylation of 2-alkyl-5,6,7,8-tetrahydro-3H-cycloheptimidazol-4-one (1) and 2-alkyl-3H-cycloheptimidazol-4-one (2) was investigated. 3-[2'-(1-tert-Butyl-1H-tetrazol-5-yl)biphenyl-4-ylmethyl]-2-propyl-5,6,7,8-tetrahydro-1H-cycloheptimidazol-4-one (6) was preferentially obtained under the conditions by using NaH in DMF or THF. On the other hand, 3-[2'-(1-tert-butyl-1H-tetrazol-5-yl)biphenyl-4-ylmethyl]-2-propyl-5,6,7,8-tetrahydro-3H-cycloheptimidazol-4-one (5), the synthetic intermediate compound of Pratosartan, was obtained selectively in the presence of n-Bu(4)NBr in toluene by using aqueous sodium hydroxide as a base. In this reaction, it was found that the concentration of the alkaline solution influences its regioselectivity. This selectivity was observed even for aldehyde and ester derivatives.


Subject(s)
Cycloheptanes/chemistry , Imidazoles/chemistry , Alkylation , Catalysis , Magnetic Resonance Spectroscopy , Solutions , Solvents , Spectrophotometry, Infrared
11.
Neurol Res ; 28(2): 196-9, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16551440

ABSTRACT

OBJECTIVES: Changes in systemic arterial blood pressure and the degree of cerebral vasospasm were investigated in 125 patients with aneurysmal subarachnoid hemorrhage. METHODS: Systemic arterial blood pressure was measured every 2 hours in each patient for a period of more than 2 weeks, and a fall in systemic blood pressure (FBP) was defined as a decrease of >40 mmHg of systolic blood pressure between two consecutive measurements. RESULTS: A total of 91 FBPs occurred in 52 (41.6%) of 125 patients despite specific post-operative management to prevent hypovolemia. Five (5.5%) of the 91 FBPs occurred just before the onset of symptomatic vasospasm. Symptomatic vasospasm was observed in 36 (69.2%) of 52 patients with FBP and in 32 (43.8%) of 73 patients without FBP (p<0.01, chi-squared test). A hypodense area on computed tomographic scans in association with cerebral vasospasm was observed in 25 (48.1%) of 52 patients with FBP and in 21 (28.8%) of 73 patients without FBP (p<0.05). DISCUSSION: We conclude that FBP might result from delayed cerebral vasospasm and/or brain dysfunction owing to subarachnoid hemorrhage itself.


Subject(s)
Hypotension/etiology , Subarachnoid Hemorrhage/complications , Vasospasm, Intracranial/etiology , Aged , Blood Pressure/physiology , Brain/blood supply , Brain/diagnostic imaging , Brain/physiopathology , Cerebral Arteries/physiopathology , Female , Humans , Hypotension/physiopathology , Male , Middle Aged , Neurosurgical Procedures , Subarachnoid Hemorrhage/physiopathology , Tomography, X-Ray Computed , Treatment Outcome , Vascular Surgical Procedures , Vasospasm, Intracranial/physiopathology
12.
Appl Opt ; 45(5): 975-83, 2006 Feb 10.
Article in English | MEDLINE | ID: mdl-16512541

ABSTRACT

We describe data compression in phase-shifting digital holography. We demonstrate by experimentation that an image of a diffusely reflecting object can be reconstructed only by phase data of the derived complex amplitude. It is shown that reduction of the bit depth of the phase data does not seriously damage the image even down to 1 bit. We observe enhancement of halo in the image with low bit depths. This tendency is verified quantitatively by a one-dimensional simulation. Our procedure for smoothing the images that result from the data-compression methods is shown to be effective.

13.
Brain Res ; 1040(1-2): 36-43, 2005 Apr 08.
Article in English | MEDLINE | ID: mdl-15804424

ABSTRACT

Transient forebrain ischemia induces calpain-mediated degradation of the neuronal cytoskeleton, alpha-fodrin, and this results in ischemic neuronal death. In this study, we investigated the spatial distribution and temporal changes of calpain-catalyzed alpha-fodrin proteolysis in focal cerebral ischemia and examined the effects of a calpain inhibitor. Ischemia was induced in gerbils by 3-h middle cerebral artery occlusion followed by reperfusion. Animals were divided into four groups: a sham-operated group, an ischemic group, a vehicle-treated group, and a calpain inhibitor-treated group. Intravenous injections of vehicle or calpain inhibitor I were administered 30 min before ischemia. Infarct volumes were measured 1 day after reperfusion and the spatial distribution of calpain-catalyzed alpha-fodrin proteolysis was investigated by immunohistochemistry 15 min, 1 h, 4 h, and 1 day after reperfusion. Infarct volume (mean +/- SD) in the ischemic group and the vehicle-treated group was 204.6 +/- 19.1 mm3 and 212.4 +/- 16.3 mm3, respectively, and the calpain inhibitor I reduced the infarct volume [149.4 +/- 25.2 mm3 (P < 0.05)]. Immunoblot analysis demonstrated that calpain inhibitor reduced proteolysis. Ischemia induced fodrin proteolysis in the ischemic core and the peri-infarct zone within 15 min after reperfusion, with proteolysis developing quickly in the ischemic core and more slowly in the peri-infarct zone. Proteolysis preceded neuronal death in the peri-infarct zone. Calpain inhibitor I ameliorated neuronal death in the peri-infarct zone but not in the ischemic core. Thus, calpain plays a pivotal role on focal ischemia as well as in global ischemia.


Subject(s)
Brain Ischemia/enzymology , Calpain/metabolism , Animals , Brain/drug effects , Brain/enzymology , Brain Ischemia/prevention & control , Calpain/analysis , Calpain/antagonists & inhibitors , Catalysis/drug effects , Female , Gerbillinae , Glycoproteins/pharmacology , Glycoproteins/therapeutic use , Peptide Hydrolases/analysis , Peptide Hydrolases/metabolism
14.
Neurosci Lett ; 373(3): 222-5, 2005 Jan 20.
Article in English | MEDLINE | ID: mdl-15619547

ABSTRACT

We performed serial measurements of 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha), a non-enzymatic derived arachidonyl peroxide, in the cerebrospinal fluid (CSF) of 34 patients with subarachnoid hemorrhage (SAH). Patients were treated with open or endovascular surgery within 48 h of onset. Delayed cerebral vasospasm was verified by the presence of a low-density area on CT scan indicating focal cerebral infarction occurring after symptomatic delayed vasospasm. Concentrations of 8-iso-PGF2alpha in the CSF of 15 patients exhibiting delayed cerebral vasospasm were compared with those of 19 patients who did not exhibit vasospasm. The concentrations of 8-iso-PGF2alpha in the CSF of patients showing vasospasm were 42.4+/-37.1 pg/ml (mean+/-S.D., n=12) on Days 0-2, 66.4+/-41.0 pg/ml (n=14) on Days 3-5, 118.5+/-89.9 pg/ml (n=15) on Days 6-8, 86.2+/-70.2 pg/ml (n=11) on Days 9-11, 48.8+/-31.8 pg/ml (n=10) on Days 12-14, 27.8+/-20.1 pg/ml (n=7) after Day 20, while the concentrations in patients not showing vasospasm were 24.8+/-12.0 pg/ml (n=18) on Days 0-2, 25.7+/-15.2 pg/ml (n=19) on Days 3-5, 47.5+/-52.3 pg/ml (n=18) on Days 6-8, 56.7+/-72.0 pg/ml (n=13) on Days 9-11, 34.2+/-53.1 pg/ml (n=15) on Days 12-14, 20.1+/-18.2 pg/ml (n=10) after Day 20. CSF concentrations of 8-iso-PGF2alpha on Days 3-5 and Days 6-8 were significantly higher in patients showing vasospasm as compared to patients not showing vasospasm. CSF levels of 8-iso-PGF2alpha in patients showing vasospasm gradually increased in the days after onset of SAH and peaked on Days 6-8. Levels returned to normal after Day 20. These values on Days 3-5, Days 6-8, and Days 9-11 were significantly higher than the value after Day 20. Considering these data and the biological activities of 8-iso-PGF2alpha, such as development of inflammation, membrane perturbation and vasoconstriction, we conclude that 8-iso-PGF2alpha may play a role in delayed cerebral vasospasm after SAH.


Subject(s)
Dinoprost/analogs & derivatives , Dinoprost/cerebrospinal fluid , Subarachnoid Hemorrhage/cerebrospinal fluid , Vasospasm, Intracranial/cerebrospinal fluid , Adult , Aged , Aged, 80 and over , Arachidonic Acids , Female , Humans , Male , Middle Aged , Peroxides , Statistics, Nonparametric , Subarachnoid Hemorrhage/pathology , Vasospasm, Intracranial/pathology
15.
Surg Neurol ; 62(3): 238-43; discussion 243-4, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15336869

ABSTRACT

BACKGROUND: The surgical removal of solid, large, and deep-seated hemangioblastomas remains challenging because it is difficult to control bleeding during the procedure. We used preoperative radiosurgery in a solid, highly vascular hemangioblastoma at the left cerebello-pontine angle and present our angiographic, operative, and histologic findings. CASE DESCRIPTION: A 37-year-old paraplegic woman with multiple hemangioblastomas was re-admitted to our clinic with cerebellar ataxia 6 years after resection of a tumor at the fourth ventricle. A vertebral artery angiogram revealed that the 3.5 cm diameter hemangioblastoma at the left cerebello-pontine angle was highly vascular and fed by the left anterior inferior cerebellar artery and posterior inferior cerebellar artery. Nine months before surgical removal it was treated with stereotactic radiosurgery (gamma knife, margin dose 28 Gy) to inhibit tumor progression and to reduce its vascularity. The tumor was totally removed via the left lateral suboccipital approach; bleeding was well controlled and there were no complications. Pathologic examination of the content of the excised tumor revealed coagulation necrosis with hyaline degeneration of the tumor vessels, resulting in a marked decrease in its vascularity. CONCLUSION: Preoperative radiosurgery led to a marked reduction in the vascularity of this hypervascular hemangioblastoma and was useful for controlling bleeding from the tumor during resection. We succeeded to remove the vascular-rich hemangioblastma after the intentional preoperative radiosurgery. The pathologic changes induced by radiotherapy were confirmed by operative finding.


Subject(s)
Cerebellar Neoplasms/surgery , Cerebellopontine Angle/blood supply , Cerebellopontine Angle/surgery , Hemangioblastoma/surgery , Neovascularization, Pathologic/surgery , Radiosurgery/methods , Adult , Cerebellar Neoplasms/diagnostic imaging , Cerebellar Neoplasms/pathology , Female , Hemangioblastoma/diagnostic imaging , Hemangioblastoma/pathology , Humans , Neovascularization, Pathologic/diagnostic imaging , Neovascularization, Pathologic/pathology , Radiography
16.
AJNR Am J Neuroradiol ; 25(5): 871-2, 2004 May.
Article in English | MEDLINE | ID: mdl-15140738

ABSTRACT

A 6-year-old girl was admitted for transoral penetrating injury by a half-split chopstick. Subsequent CT imaging examinations showed that the chopstick had passed between the basion and the dens and reached the subarachnoid space just at the medulla oblongata. A sagittal reconstructed CT scan was useful for the evaluation of the injury. Imaging findings and their clinical relevance are discussed.


Subject(s)
Brain Injuries/diagnostic imaging , Palate, Soft/injuries , Wounds, Penetrating/diagnostic imaging , Child , Female , Humans , Tomography, X-Ray Computed
17.
Article in English | MEDLINE | ID: mdl-15120710

ABSTRACT

The current study assessed the differential incorporation of 12-hydroperoxyeicosatetraenoic acid (12-HPETE), arachidonic acid (AA), 12-hydroxyeicosatetraenoic acid (12-HETE) and the linoleic acid (LA) oxidation products, 13-hydroxyoctadecadienoic acid (13-HODE) and 13-hydroperoxyoctadecadienoic acid (13-HPODE), into human umbilical vein endothelial cells (HUVEC). Approximately 80-90% of AA (10(-8)-10(-5)M) and 80% of LA (10(-8)-10(-5)M) were incorporated into HUVEC within 12h, while less than 50% of the hydroxy metabolites (12-HETE, 12-HPETE, 13-HODE, 13-HPODE) were incorporated into HUVEC over 48h. Further, treatment of HUVEC with either 12-HPETE or 13-HPODE (concentrations of 10(-5)M) had no effect on cell number at a 48h time point when compared with control. These results demonstrate that exogeneous hydroxy metabolites are incorporated into HUVEC to a lesser degree than were endogenous fatty acids. Further, we speculate that 12-HPETE and 13-HPODE are rapidly metabolized to substances without significant cytotoxic effects.


Subject(s)
12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/metabolism , Arachidonic Acid/metabolism , Endothelial Cells/metabolism , Leukotrienes/metabolism , Linoleic Acids/metabolism , Lipid Peroxides/metabolism , 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/toxicity , Cells, Cultured , Humans , Leukotrienes/toxicity , Linoleic Acids/toxicity , Lipid Peroxides/toxicity , Umbilical Veins/cytology
18.
No Shinkei Geka ; 31(10): 1099-103, 2003 Oct.
Article in Japanese | MEDLINE | ID: mdl-14598647

ABSTRACT

A 66-year-old man suffered from subarachnoid hemorrhage due to the rupture of a right middle cerebral artery aneurysm that was detected by 3D-CTA. He underwent an emergent clipping operation. Incidentally, postoperative DSA demonstrated dural arteriovenous fistula in the left anterior cranial fossa, which was fed by the left anterior ethmoidal artery and drained into the superior sagittal sinus via the cortical vein of the left frontal lobe. We performed electrocoagulation and division of the fistula at the second surgery. Subsequently, he underwent a ventriculo-peritoneal shunt and was discharged without any neurological deficits. We reviewed reported cases of rare association of ruptured cerebral aneurysm and dural arteriovenous fistula in the left anterior cranial fossa.


Subject(s)
Aneurysm, Ruptured/complications , Central Nervous System Vascular Malformations/complications , Intracranial Aneurysm/complications , Aged , Aneurysm, Ruptured/surgery , Central Nervous System Vascular Malformations/surgery , Cranial Fossa, Anterior/blood supply , Electrocoagulation , Humans , Intracranial Aneurysm/surgery , Male , Ventriculoperitoneal Shunt
19.
Brain Res ; 984(1-2): 122-32, 2003 Sep 12.
Article in English | MEDLINE | ID: mdl-12932846

ABSTRACT

We investigated the relationship between the activity of calcium-dependent protease (calpain) and the ischemic neuronal damage. We also investigated the mechanism of ischemic resistance in astrocytes. In gerbil, a 10-min forebrain ischemia was induced by occlusion of both common carotid arteries. The calpain-induced proteolysis of cytoskeleton (fodrin) was examined by immunohistochemistry. Immunolocalization of micro and m-calpain was also examined. Intact fodrin was observed both in neurons and astrocytes, but proteolyzed fodrin was not observed in normal brain. Fifteen minutes after ischemia, proteolysis of fodrin took place in putamen, parietal cortex and hippocampal CA1. The proteolysis extended to thalamus 4 h after ischemia after which the immunoreactivity faded down in all areas except hippocampus. On day 7, the proteolysis was still observed only in hippocampus. Neurons with the proteolysis of soma resulted in neuronal death. Throughout the experiment, the proteolysis was not observed in astrocytes. micro -Calpain was observed only in neurons but m-calpain was observed both in neurons and astrocytes. The ischemia induced only micro -calpain activation, which resulted in fodrin proteolysis of neurons with differential spatial distribution and temporal course. The proteolysis was developed rapidly and was completed within 24 h in all vulnerable regions except hippocampal CA1. The proteolysis preceded the neuronal death. The mechanism of the proteolysis seemed to be involved by Ca(2+) influx via glutamate receptor and rapid neuronal death seemed reasonable. The reason why neuronal death in CA1 evolved slowly was not clarified. In astrocytes, fodrin was not proteolyzed by m-calpain. The low Ca(2+)-sensitivity of m-calpain may be the reason of ischemic resistance in astrocytes.


Subject(s)
Calpain/metabolism , Cytoskeleton/enzymology , Neurons/enzymology , Prosencephalon/enzymology , Animals , Brain Ischemia/enzymology , Brain Ischemia/prevention & control , Calpain/analysis , Calpain/antagonists & inhibitors , Cytoskeleton/chemistry , Cytoskeleton/drug effects , Enzyme Activation/drug effects , Enzyme Activation/physiology , Female , Gerbillinae , Glycoproteins/pharmacology , Glycoproteins/therapeutic use , Hippocampus/chemistry , Hippocampus/drug effects , Hippocampus/enzymology , Neurons/chemistry , Neurons/drug effects , Prosencephalon/chemistry , Prosencephalon/drug effects
20.
Appl Opt ; 42(10): 1769-72, 2003 Apr 01.
Article in English | MEDLINE | ID: mdl-12683754

ABSTRACT

A new scheme of the Faraday effectcurrent sensor of a magnetic ring-core type is reported. With this scheme a uniaxial magnetic garnet film is obliquely inserted into a very narrow gap in the ring core and a probe light beam is passed through the garnet film in the transverse direction to the core. It is experimentally demonstrated that this current sensor shows good sensitivity as well as good isolation from surrounding currents, particularly because of the very narrow core gap allowed. This transverse scheme is much simpler and less expensive than the known longitudinal scheme and can offer a practical optical current sensor of a ring-core type.

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