651
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Ishiai S, Seki K, Koyama Y, Yokota T. Mechanisms of unilateral spatial neglect in copying a single object. Neuropsychologia 1996; 34:965-71. [PMID: 8843062 DOI: 10.1016/0028-3932(96)00017-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The present study examined 13 patients with typical left unilateral spatial neglect to explore the mechanisms of neglect in copying a single object. All patients identified the figure of a sunflower as a flower that had petals all around the central circle. Besides, in the free viewing of the flowers prepared by the examiner, 10 of the 13 patients could discriminate between the presence and absence of the left-sided petals. When copying the flower, however, they always left the left side unfinished without noticing the incompleteness. Whether perception in the left visual field was impaired or not was irrelevant to the performances in the copying and the free viewing of the flowers. We consider the mechanism of left unilateral spatial neglect in copying a flower as follows. Small leftward shift of attention may take place during the free observation of the stimulus flower. While copying, however, neglect patients pay attention exclusively to the right-sided petals they are drawing. The strong engagement of attention to the right side results in the lack of discovery of the left-sided omission. The close integration of attentional and premotor mechanisms seems to be crucial for the appearance of unilateral spatial neglect in copying a single object.
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652
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Uetera Y, Yokota T, Hiramatsu K, Sato K, Ogawa M. Role of bacterial biofilms in the chemotherapy of cholangitis with brown pigment stones. Chemotherapy 1996; 42:363-73. [PMID: 8874976 DOI: 10.1159/000239468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The purpose of the present study was to clarify the role of biofilms in the chemotherapy of cholangitis. In 1 case of recurrent cholangitis with intrahepatic stones, the patient underwent right hepatectomy after chemotherapy was performed for 42 weeks. In the other case, chemotherapy including ciprofloxacin was performed during an attack of recurrent cholangitis. Repeated culture of bile specimens yielded negative results, whereas culture of the choledochal stone yielded Pseudomonas aeruginosa. We observed an acute transient IgM response to a component of the biofilm of P. aeruginosa (alginate) in this case. In both cases, electron microscopy revealed viable bacteria covered with biofilm in the component of brown pigment stones. It was concluded that biofilm is a factor of drug resistance.
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653
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Suzuki T, Nishina K, Yokota T, Hamamoto H, Tsuchiyama Y, Kiyono T, Ikeda H, Konishi A, Inoue T, Shimamura J, Kusumoto R, Kusaka S. [Case of type C chronic hepatitis developing periodic quadriplegia and Basedow's disease during interferon administration]. NIHON NAIKA GAKKAI ZASSHI. THE JOURNAL OF THE JAPANESE SOCIETY OF INTERNAL MEDICINE 1996; 85:1295-7. [PMID: 8965029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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654
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Sanjo N, Yokota T, Saitou Y, Miake H, Tanaka H. Painful bilateral abducens nerve palsy associated with anti-neutrophil cytoplasmic autoantibodies. J Neurol 1996; 243:612-3. [PMID: 8865030 DOI: 10.1007/bf00900951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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655
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Sudo K, Inoue H, Shimizu Y, Yamaji K, Konno K, Shigeta S, Kaneko T, Yokota T, Shimotohno K. Establishment of an in vitro assay system for screening hepatitis C virus protease inhibitors using high performance liquid chromatography. Antiviral Res 1996; 32:9-18. [PMID: 8863991 DOI: 10.1016/0166-3542(95)00969-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The hepatitis C virus (HCV) genome contains the code for a conserved, serine-type protease, called NS3, for the processing of the non-structural protein region of the viral polyproteins. Furthermore, a related protein, NS4A, is an effector or cofactor of NS3 protease activity in the cleavage of NS3-4A, NS4A-4B, NS4B-5A and NS5A-5B junctions. To establish an in vitro assay system for the screening of those enzyme inhibitors that inhibit the protease NS3-4A, we prepared a maltose-binding protein-NS3-NS4A fusion protein and a synthetic peptide substrate that mimics the NS5A-5B junction. Cleavage of the synthetic peptide was analyzed by reversed-phase high performance liquid chromatography (HPLC). We showed that the enzymatic activity of the NS3-NS4A fusion protein was enhanced in comparison to the NS3 protein alone. The assay conditions for optimum NS3-4A protease activity were determined to be pH 7.6 and 37 degrees C. In addition, we evaluated several protease inhibitors using the same HPLC assay system. The activity of HCV protease NS3-4A was inhibited by 2714.4 microM diisopropyl fluorophosphate, 270.8 microM N-tosyl-L-lysyl chloromethyl ketone, and 825.5 microM chymostatin. The results of the present study indicated that the synthetic peptide substrate and HPLC assay system are suitable for studying HCV protease activity and may facilitate the development of anti-HCV therapeutic reagents.
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656
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Fujii R, Sunakawa K, Sato Y, Yokota T, Yoshimura K, Kondoh Y, Kawaoi Y, Terashima I, Meguro H, Niinou K, Toyonaga Y, Ishihara T, Iwai N, Nakamura H, Kuno K, Miyajima Y, Sakurai M, Itoh M, Kawasaki H, Suga S, Kamiya H, Fujiwara T, Inui T, Taniguchi K, Nakayama M. [Optimum dose study of cefozopran in the pediatric field]. THE JAPANESE JOURNAL OF ANTIBIOTICS 1996; 49:663-77. [PMID: 8828069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Cefozopran (SCE-2787, CZOP) was administered to patients with pediatric infections three to four times daily by intravenous injection or 30-minute intravenous drip infusion, and investigations were made in individual cases, on relationships among doses, pharmacokinetics, effects on pathogenic bacteria and MIC against them, and clinical effects. The following results on optimal doses of CZOP were obtained. 1. Clinical cases in which CZOP was administered at a dose of 10 mg (potency)/kg The subjects were 7 patients including 4 patients with pneumonia. Severities of the diseases were severe in one of the patients with pneumonia, and moderate in the other patients. The MIC against pathogenic bacteria (4 strains) isolated from these cases ranged from 0.2 to 1.56 micrograms/ml. The serum concentrations were in a range between 1.4 and 7.6 micrograms/ml at 4 hours after administration. In some cases, the serum concentrations were lower than the MICs, though slightly. In the clinical evaluation, CZOP was excellent in 3 cases, good in 2 cases and fair in 1 case. The evaluation was impossible in 1 case. The efficacy rate was 83.3% (5/6). In bacteriological evaluation, 3 out of the 4 strains disappeared. Adverse reactions and abnormal laboratory test values were not observed. 2. Cases in which CZOP was administered at a dose of 20 mg (potency)/kg The subjects were 5 patients including 2 with pneumonia, and severities were severe in one of the patients with pneumonia, and moderate in the other patients. The MICs against the pathogenic bacteria (3 strains) isolated from these cases ranged from 0.1 to 1.56 micrograms/ml. While, serum concentrations at 4 hours after administration were in a range between 3.0 and 7.7 micrograms/ml sufficiently exceeding the MICs. In the clinical evaluation, CZOP was excellent in 1 case and good in four cases, with an efficacy rate of 100% (5/5). In the bacteriological evaluation, all the 3 strains disappeared. No adverse reactions were observed, but an abnormal laboratory test value showing eosinophilia was noted in one case. 3. Cases in which CZOP was administered at a dose of 40 mg (potency)/kg The subjects were 5 patients including 3 with pneumonia. The severity was moderate in 2 of the pneumonia patients, and severe in the other three cases. The MICs against the pathogenic bacteria (4 strains) isolated from these cases were in a range between 0.1 and 0.78 micrograms/ml. The serum concentrations at 4 hours after administration ranged from 6.5 to 21.9 micrograms/ml, sufficiently exceeding the MICs. In the clinical evaluation, CZOP was excellent in 4 cases and good in 1 case, with an efficacy rate of 100% (5/5). The efficacy rate in the bacteriological evaluation was also 100%. As adverse reaction, red urine was observed in one case. Eosinophlia was noted in one case in the laboratory tests. When CZOP was administered to patients with pediatric infections at a dose of 10 mg (potency)/kg, the clinical effect of the drug was insufficient in a case in which serum concentration of CZOP at 4 hours after administration was lower than the MICs against the pathogenic bacteria. When CZOP was administered at a dose of 20 mg (potency)/kg, sufficient concentrations were obtained, and the drug efficacies were found to be excellent or good in all cases. Therefore, the effective dose normally used is considered to be 20 mg (potency)/kg. When CZOP was administered at a dose of 40 mg (potency)/kg, the drug was found to be excellent or good in all of the cases although the severities were high in more than half of the cases tested. In addition, the rate of excellent efficacies was 80% (4/5). Furthermore, no severe adverse reactions were observed. It was, therefore, confirmed that CZOP should be administered at a dose of 40 mg (potency)/kg in severe or intractable cases.
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657
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Irisawa C, Yoshimura Y, Yokota T, Yamaguchi O, Kondou Y, Hamasaki T, Yamad Y, Kurosu S, Chiba R. [Histological effects of short term endocrine therapy on prostatic cancer]. Nihon Hinyokika Gakkai Zasshi 1996; 87:977-85. [PMID: 8776964 DOI: 10.5980/jpnjurol1989.87.977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The objective of this study is to investigate the pathological changes which occurred in prostatic cancer shortly after the commencement of endocrine therapy. METHODS Fourty-three patients underwent radical prostatectomy immediately after the short term endocrine therapy (treatment period was within one month) and the histological pictures of operative specimens were compared to those obtained from the pretreatment biopsy specimens. RESULTS Degenerative changes of cancer cells, such as nuclear and cytoplasmic vacuole, collapse of the cytoplasm and the appearance of naked hyperchromatic nucleus were noticed after the short term endocrine therapy. Especially in the cases which were histologically evaluated to be poorly differentiated in the biopsy specimens, not only degenerative changes but also destruction of cancer nests caused by cell death were observed. The histological effects affected by short term endocrine treatment had no relation to the prognosis, but in the cases of stage D2, the pathological grade judged by post-therapeutic specimens were found to be useful for the prediction of prognosis. CONCLUSION Endocrine therapy induces remarkable pathological changes in prostatic cancer within a very short time after beginning treatment.
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658
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Yan ZQ, Yokota T, Zhang W, Hansson GK. Expression of inducible nitric oxide synthase inhibits platelet adhesion and restores blood flow in the injured artery. Circ Res 1996; 79:38-44. [PMID: 8925566 DOI: 10.1161/01.res.79.1.38] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
NO generated by endothelial cells is vasoprotective by antagonizing platelet adhesion and smooth muscle contraction. Since vascular smooth muscle cells (VSMCs) produce NO in response to cytokine stimulation and after arterial injury, we speculated that NO produced by VSMCs could compensate for the loss of endothelium. Using balloon catheter denudation of the rat carotid artery as a model for arterial injury and restenosis, we have evaluated the time course of expression of inducible NO synthase (iNOS) by in situ hybridization and immunohistochemistry and studied the effect of iNOS on platelet adhesion and blood flow of the injured vessel. iNOS mRNA and protein were expressed in the innermost layer of the media from day 1 and were subsequently detected in the neointima, whereas no expression was detectable in the uninjured artery. Systemic administration of N omega-nitro-L-arginine methyl ester (L-NAME) resulted in a twofold to threefold increase in the adhesion of 111In-labeled platelets to the injured vessel wall. Platelet adhesion was also enhanced threefold by local delivery of L-NAME from a gel surrounding the injured vessel, whereas the stereoisomer, D-NAME, had no effect. Finally, inhibition of NO synthase led to a 24% reduction of the blood flow in the injured carotid artery. These results demonstrate that arterial injury triggers the expression of iNOS in the lesion and that NO produced by iNOS inhibits platelet adhesion and restores blood flow. This could explain the disappearance of platelet thrombi from deendothelialized arterial surfaces within a few days after injury and indicates the importance of NO generated by iNOS for the maintenance of vascular tone. Thus, expression of iNOS in lesions may represent a protective mechanism that compensates for the loss of endothelium.
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659
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Yokota T, Saito Y, Yuki N, Tanaka H. Persistent increased threshold of electrical stimulation selective to motor nerve in multifocal motor neuropathy. Muscle Nerve 1996; 19:823-8. [PMID: 8965834 DOI: 10.1002/mus.880190702] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In multifocal motor neuropathy (MMN) the threshold of electrical stimulation showed a persistent, marked increase for the motor nerve which decreased after treatment with intravenous immunoglobulin or oral cyclophosphamide; whereas, the threshold was normal for the sensory nerve. This discrepancy of the thresholds for motor and sensory nerves indicates that the increased threshold for motor nerve is not caused by change in perineural capacitance, such as subperi- and endoneural edema or perineural thickening. Inching studies showed that the site of the elevated motor nerve threshold was closely associated with conduction slowing and block. For the cause of the increased threshold, therefore, we suppose the presence of a factor which interferes with reorganization of the nodal property in the remyelinative process or which directly blocks sodium channels where the blood-nerve barrier is impaired in MMN.
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660
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Hatta T, Nakagawa Y, Takai K, Nakada S, Yokota T, Takaku H. Inhibition of influenza virus RNA polymerase and nucleoprotein genes expression by unmodified, phosphorothioated, and liposomally encapsulated oligonucleotides. Biochem Biophys Res Commun 1996; 223:341-6. [PMID: 8670284 DOI: 10.1006/bbrc.1996.0896] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We have demonstrated that antisense phosphodiester (ODNs) and phosphorothioate oligonucleotides (S-ODNs) inhibit CAT (chloramphenicol acetyltransferase) protein expression in the clone 76 cell line, which is a derivative of the murine C127 cell line. This cell line expresses the influenza virus RNA polymerase and nucleoprotein (NP) genes in response to treatment with dexamethasone. Phosphodiester, phosphorothioate, and liposomally encapsulated oligonucleotides with four target sites (PB1, PB2, PA, and NP) were synthesized and tested for inhibitory effects by a CAT-ELISA assay using the clone 76 cell line. The ODNs and S-ODNs complementary to the sites of the PB2-AUG and PA-AUG initiation codons showed highly inhibitory effects. On the other hand, the inhibitory effect of the S-ODNs targeted to PB1 was considerably decreased in comparison with the other three target sites. Liposome encapsulation afforded oligomer protection in serum-containing medium and substantially improved cellular accumulation. The liposomal encapsulated oligonucleotides exhibited higher inhibitory activity than the free oligonucleotides. The activities of the unmodified oligonucleotides are effectively enhanced by using the liposomal carrier.
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661
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Yokota T, Inaba A, Yuki N, Ichikawa T, Tanaka H, Saito Y, Kanouchi T. The F wave disappears due to impaired excitability of motor neurons or proximal axons in inflammatory demyelinating neuropathies. J Neurol Neurosurg Psychiatry 1996; 60:650-4. [PMID: 8648332 PMCID: PMC1073949 DOI: 10.1136/jnnp.60.6.650] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVES Investigation of pathophysiology of F wave disappearance in demyelinating neuropathies. METHODS The peripheral motor nerve conduction was studied by motor evoked potential (MEP) on transcranial magnetic stimulation as well as conventional nerve conduction studies before and after the treatment in 26 patients with inflammatory demyelinating neuropathies. In addition, serum antiganglioside antibodies in the acute or active stage were examined. RESULTS The F wave was abolished in 10 patients. Seven of the 10 patients showed motor evoked potentials (MEPs) on transcranial magnetic stimulation that ranged from 1-4 mV. In six of them the F wave reappeared in the recovery stage, but the MEP size did not change. This may be caused by humoral factors, because the F wave reappeared immediately after plasma exchange or intravenous immunoglobulin treatment. A correlation of F wave disappearance with the presence of serum antiganglioside antibodies was found. CONCLUSIONS The major pathophysiology of F wave disappearance in demyelinating neuropathies is impairment of motor neuron excitability or prolonged refractoriness of the most proximal axon for backfiring. The conventional interpretation that absent F waves suggest a conduction block at the proximal site is often inadequate.
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662
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Takagi M, Heike T, Yokota T. [Analysis of self-renewal mechanism of hematopoietic stem cells using transgenic mice expressing cytokine receptors]. TANPAKUSHITSU KAKUSAN KOSO. PROTEIN, NUCLEIC ACID, ENZYME 1996; 41:1297-305. [PMID: 8741652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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663
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Yokota T. [Roentgenological and histomorphological studies of the knee joint in rheumatoid arthritis]. RYUMACHI. [RHEUMATISM] 1996; 36:503-13. [PMID: 8779787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In order to study the disease process of rheumatoid arthritis in the knee joint, clinical and roentgenological analysis as well as histomorphological study of the proximal tibia taken at total knee arthroplasty procedure were carried out. The natural course of eight patients who had been followed 12.7 years on an average were studied in respect to range of motion, swelling, pain, instability of the knee joints along with radiographical appearance of the knee joints and other locations such as hand, spine and other major joints. There were two extreme types: one which led to obvious joint instability and one which ended up with joint contracture. The majority of the cases, however, fell between the two types. These three groups well corresponded to the three types proposed earlier by Katsube: unstable, stiff and standard types, respectively. For the roentgenological analysis, 148 knees of 80 preoperative patients were also subjected. The findings included osteoporosis, abnormal femoro-tibial angle, osteophyte formation, bone destruction with or without osteosclerosis. There were apparent bone destruction and a tendency toward valgus demormity in the unstable type, whereas apparent osteoporosis and little osteosclerosis of the tibial plateau were found in the stiff type. In the standard type, there were osteophyte formation and osteosclerosis of the tibial plateau as usually seen in osteoarthritic knees. For the histomorphological study, 30 patients were given tetracycline hydrochloride preoperatively for tetracycline labeling and total of 38 knees were thus examined. The specific findings in the unstable type included severe pannus formation and bone absorption, and those in the stiff type were severe osteoporosis with articular cartilage degeneration and decreased mineralization. No specific findings were observed in the standard type.
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664
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Ijichi K, Fujiwara M, Nagano H, Matsumoto Y, Hanasaki Y, Ide T, Katsuura K, Takayama H, Shirakawa S, Aimi N, Shigeta S, Konno K, Matsushima M, Yokota T, Baba M. Anti-HIV-1 activity of thiadiazole derivatives: structure-activity relationship, reverse transcriptase inhibition, and lipophilicity. Antiviral Res 1996; 31:87-94. [PMID: 8793012 DOI: 10.1016/0166-3542(96)00950-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The structure-activity relationship of the non-nucleoside HIV-1-specific reverse transcriptase (RT) inhibitors 4-phenyl-1,2,5-thiadiazol-3-yl N,N-dialkylcarbamate (TDA) derivatives was investigated with respect to their anti-HIV-1 activity, RT inhibition, and lipophilicity. 4-Phenyl-1,2,5-thiadiazol-3-yl N,N-dimethylcarbamate inhibited HIV-1-induced cytopathic effect (CPE) by 50% at a concentration of 28.8 microM in MT-4 cells. The activity increased more than 100-fold when the hydrogens at the 2-position and the 6-position in phenyl moiety were substituted by chlorines. However, the derivative with a chlorine at the 4-position of phenyl moiety did not show any inhibition of HIV-1 replication at its non-toxic concentrations. All of the 4-(2,6-dichlorophenyl)-1,2,5-thiadiazol-3-yl N-methyl-N-alkylcarbamates proved inhibitory to HIV-1 replication in the nanomolar concentration range. The TDA derivatives that showed anti-HIV-1 activity also inhibited RT activity in an enzymatic assay. However, the TDA derivatives did not show any specific inhibition of a non-nucleoside RT inhibitor (NNRTI)-resistant mutant and its RT activity. When the TDA derivatives were examined for their inhibitory effect on HIV-1 replication in the presence of 50% human serum, the activity significantly decreased depending on-their lipophilicity.
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665
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Ijichi K, Fujiwara M, Mori K, Morozumi M, Machida H, Shigeta S, Konno K, Yokota T, Baba M. Antiviral activities of nucleotide heterodimers against human immunodeficiency virus type 1 in vitro. Antiviral Res 1996; 31:115-20. [PMID: 8793015 DOI: 10.1016/0166-3542(96)00945-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Nucleotide heterodimers were synthesized and examined for their inhibitory effects on the replication of human immunodeficiency virus type 1 (HIV-1), including HIV-1 reverse transcriptase (RT) inhibitor-resistant mutants. 3'-Azido-3'-deoxythymidilyl-(5')-phospho-(5')-6-[(3', 5'-dimethylphenyl)thio]-5-ethyl-1-[(2-hydroxyethoxy)methyl]uracil (AZT-P-E-HEPU-dM) and 3'-azido-3'-deoxythymidilyl-(5')-phospho-(5')-2', 3'-dideoxyinosine (AZT-P-ddI) proved to be highly potent and selective inhibitors of HIV-1 (IIIB strain) in MT-4 cells. The mechanism of inhibition by these heterodimers may be attributed to their degradation and the formation of each constituent. AZT-P-E-HEPU-dM was also markedly inhibitory to an AZT-resistant mutant (HIV-1-IIIB/AZT) and an E-HEPU-dM-resistant mutant (HIV-1-IIIB-R). However, AZT-P-ddI was found to have a less inhibitory effect on HIV-1-IIIB/AZT than on HIV-1-IIIB. The heterodimers of (5',5') AZT and ribavirin (AZT-P-Ribavirin) and (5',5') ddI and ribavirin (ddI-P-Ribavirin) were also synthesized: AZT-P-Ribavirin inhibited HIV-1 replication, but ddI-P-Ribarvirin did not.
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666
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Yokota T, Eguchi K, Satoh T. Correlated discharges of two neurons in rat gustatory cortex during gustatory stimulation. Neurosci Lett 1996; 209:204-6. [PMID: 8736646 DOI: 10.1016/0304-3940(96)12619-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
During application of tastants into the oral cavity correlated activities were observed in 27 of 64 neuron pairs recorded simultaneously in the gustatory cortex of anesthetized rats. The mean frequency of correlated discharges as assessed from the size of the peak appearing in the cross-correlogram was lower (0.2-0.33 spikes/s) and the mean width of the peaks was wider (8 ms) as compared to those reported in the gustatory relay stations in the brainstem. In a few cases troughs were formed or peaks appeared with a long delay.
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667
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Abstract
We experienced a case of calcified ball thrombus that was fixed to the atrial septum in the left atrium. This patient had no symptoms and no cardiac dysfunction. the thrombus was detected during preoperative work-up of a retroperitoneal tumor. The process of fixation to the atrial septum and calcification is unclear.
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668
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Ijichi K, Fujiwara M, Shigeta S, Konno K, Yokota T, Baba M. Different properties of wild type and drug-resistant mutants of human immunodeficiency virus type 1 reverse transcriptase in vitro. Microbiol Immunol 1996; 40:353-8. [PMID: 8805099 DOI: 10.1111/j.1348-0421.1996.tb01079.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Drug-resistant mutants of human immunodeficiency virus type 1 (HIV-1) emerge during treatment with various reverse transcriptase (RT) inhibitors in vitro and in vivo. However, the virological nature and pathogenic importance of these mutants have not been fully elucidated. In this study, we have examined HIV-1 mutants resistant to 3'-azido-3'-deoxythymidine (AZT) and nonnucleoside RT inhibitors (NNRTIs) for their infectivity, RT activity, and replication in MT-4 cells. Although the infectivity of AZT- and NNRTI-resistant mutants was similar, the RT activity of AZT-resistant mutants was much higher than that of NNRTI-resistant mutants and their wild types. Furthermore, the RT activity of NNRTI-resistant mutants was significantly lower than that of the wild types. In contrast, the replication of NNRTI-resistant mutants was found to be greater than that of AZT-resistant mutants and the wild types. When HIV-1 proviral DNA (cDNA) synthesis was examined by PCR in MT-4 cells infected with the wild type, AZT-resistant mutant, or NNRTI-resistant mutant, the PCR signal of the NNRTI-resistant mutant was found to be much higher than those of the wild type and AZT-resistant mutant. These results suggest that the drug-resistant mutants differ from their corresponding wild types not only in drug sensitivity but also in other virological properties.
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669
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Ijichi K, Fujiwara M, Hanasaki Y, Katsuura K, Shigeta S, Konno K, Yokota T, Baba M. Inhibitory effect of 4-(2, 6-dichlorophenyl)-1, 2, 5-thiadiazol-3-yl-N-methyl, N-ethylcarbamate on replication of human immunodeficiency virus type 1 and the mechanism of action. BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 1996; 39:41-52. [PMID: 8799326 DOI: 10.1080/15216549600201041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In the search for effective antiviral agents, we have found 4-(2, 6-dichlorophenyl)-1, 2, 5-thiadiazol-3-yl-N-methyl, N-ethylcarbamate (RD4-2025) to be a highly potent and selective inhibitor of human immunodeficiency virus type 1 (HIV-1) in vitro. The 50% effective concentration of RD4-2025 for HIV-1-induced cytopathic effect in MT-4 cells was 37 nM, yet no antiviral activity was observed against HIV-2. In HIV-1 reverse transcriptase (RT) assays, RD4-2025 inhibited both RNA-dependent and DNA-dependent DNA polymerase activities of a recombinant HIV-1 RT with 50% inhibitory concentrations of 0.11 and 3.5 microM, respectively. However, the compound did not affect the activity of human DNA polymerase alpha. Kinetic studies revealed that the inhibition was noncompetitive with respect to dGTP as the substrate and poly(C)/(dG) 12-18 as the template/primer. These results were in accordance with those of nonnucleoside RT inhibitors (NNRTIs), such as R89439 (an alpha-anilinophenylacetamide derivative) and nevirapine, indicating that RD4-2025 also belongs to the family of NNRTIs.
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670
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Fujino Y, Koyama N, Yokota T. Differential distribution of three types of nociceptive neurons within the caudal bulbar reticular formation in the cat. Brain Res 1996; 715:225-9. [PMID: 8739643 DOI: 10.1016/0006-8993(96)00019-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Nociceptive neurons within the reticular formation (RF) caudal to the obex were studied. 197 units recorded from the lateral part of subnucleus reticularis ventralis had receptive fields in the head, 72 units recorded from the medial RF in the body, and 160 units recorded from the middle third of RF in the head and body. About half of the units tested were antidromically excited by stimulation of nucleus centralis lateralis.
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671
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Yokota T, Nishikawa Y, Koyama N, Fujino Y. Differential distribution of four types of tooth pulp neurons in the caudal medulla oblongata of the cat. Brain Res 1996; 715:230-4. [PMID: 8739644 DOI: 10.1016/0006-8993(96)00020-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The medulla oblongata caudal to the obex was explored for neurons responsive to tooth pulp (TP) stimulation in cats. Four different classes of TP neurons were found. They were TP specific neurons, trigeminal wide dynamic range neurons with TP input, trigeminal subnucleus reticularis ventralis (SRV) neurons with TP input and convergent reticular formation with TP input. They were differentially distributed within the caudal medulla oblongata.
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672
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Kunori T, Shinya F, Satomi T, Itoh J, Abe M, Takahashi M, Yokota T, Abe Y, Hiraoka K, Kawaguchi S, Tanaka I, Mochizuki M, Asano S. Spontaneous antibody-secreting cells in the stomach of gastric cancer patients. J Gastroenterol 1996; 31:161-6. [PMID: 8680533 DOI: 10.1007/bf02389512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The gastric mucosa has been regarded as an active site of humoral immunity since the discovery of Helicobacter pylori. The present study was conducted to determine the in vivo activity of gastric B cells in 53 gastric cancer patients. B-cell activity was measured by protein-A plaque assay, in which IgA-, IgM-, and IgG-plaque-forming cells (PFC) were counted. The number of PFC was associated with the stage of cancer, but the response of lymphocytes in a non-tumorous area (NML) and tumor-infiltrating lymphocytes (TIL) differed. PFC in both sites were decreased compared to n0 cancer in n1 lymph node metastasis-positive cancer, while only NML showed raised PFC in n2 + (P < 0.05, vs TIL). Cancer cells penetrating the submucosa caused the PFC of TIL (but not of NML) to decrease. Invasion of the intratumor capillary (V) or lymphatic (Ly) vessels also caused PFC to change, showing differences of Ig class; there was a decrease of PFC in V2 (IgG- and IgM-PFC) and in Ly2 (all Ig-PFC). IgA-PFC in Ly1 differed in TIL (decrease of PFC) and NML (increase). PFC also differed in TIL and NML in cancer cells, as follows: TIL < NML in tubular and poorly differentiated adenocarcinoma and TIL > NML in papillary and signet ring cell adenocarcinoma. Changes in lymph node (LNL) and blood lymphocytes were similar to those in gastric PFC whose IgA value was 10 times as much as that of LNL. The 5-year survival rate was significantly better in patients with lower rather than higher PFC such as 89% vs 68%. Gastric B cells thus appear to be active and to reflect gastric mucosal immunity.
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673
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Ozeki S, Ohtsuru A, Seto S, Takeshita S, Yano H, Nakayama T, Ito M, Yokota T, Nobuyoshi M, Segre GV, Yamashita S, Yano K. Evidence that implicates the parathyroid hormone-related peptide in vascular stenosis. Increased gene expression in the intima of injured carotid arteries and human restenotic coronary lesions. Arterioscler Thromb Vasc Biol 1996; 16:565-75. [PMID: 8624779 DOI: 10.1161/01.atv.16.4.565] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Proliferation of vascular smooth muscle cells (VSMCs) is considered to be one key event underlying the pathophysiology of restenosis after angioplasty. The parathyroid hormone-related peptide (PTHrP) and its receptor, a local autocrine and paracrine regulator of cellular growth in a variety of normal cell types, have been reported in the vicinity of VSMCs. To investigate how PTHrP might be involved in the process of neointimal formation after balloon angioplasty, we examined PTHrP expression in balloon-denuded rat carotid arteries and human coronary arteries that had been retrieved by directional atherectomy. In rat carotid arteries, the RNase protection assay and in situ hybridization demonstrated that PTHrP mRNA expression increased fourfold to sixfold 1 to 7 days after denudation and continued for 28 days, coincident with downregulation of PTH/PTHrP receptor mRNA expression. In situ hybridization and immunohistochemistry revealed that PTHrP expression in balloon-denuded carotid arteries was mainly localized to the neointima. To confirm the involvement of the PTHrP in human coronary artery restenotic lesions, immunohistochemical analysis of human coronary atherectomy specimens (23 primary and 10 restenotic lesions) was then performed. The number of intimal cells that expressed PTHrP protein was significantly higher in restenotic (407 +/- 53 cells/mm2; range, 143 to 739) than in stable angina (50 +/- 12 cells/mm2; range, 18 to 132; P<.05) or unstable angina (129 +/- 16 cells/mm2; range, 21 to 232; P<.05) specimens. These data demonstrate that PTHrP gene expression in VSMCs markedly increases during neointimal formation, supporting the hypothesis that PTHrP may play an important role in vascular stenosis as a regulator of VSMC proliferation.
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674
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Yokota T, Ohami H, Ohishi H, Hattori T, Watanabe K. Repression of acute gastric mucosal lesions by antioxidant-containing fraction from fermented products of okara (bean-curd residue). J Nutr Sci Vitaminol (Tokyo) 1996; 42:167-72. [PMID: 8780975 DOI: 10.3177/jnsv.42.167] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A crude antioxidant preparation from fermented okara (NTX) was examined for its protection against the pathogenesis of gastric ulcer in water-immersed rats. The areas of gastric mucosal lesions as well as the levels of thiobarbituric acid-reactive substances, prostaglandin E2 and hyaluronic acid in the gastric mucosa were measured in relation to the time elapsed after the imposition of stress. Comparison with those parameters in alpha-tocopherol-treated groups revealed that NTX exerted an anti-inflammatory effect on gastric injury, probably by functioning as a free radical scavenger.
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675
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Hatta T, Takai K, Yokota T, Takaku H. Inhibition of influenza virus RNA polymerase and nucleoprotein of gene expression by antisense oligonucleotides. Antiviral Res 1996. [DOI: 10.1016/0166-3542(96)80250-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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