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1.
AJNR Am J Neuroradiol ; 43(10): 1502-1507, 2022 10.
Article in English | MEDLINE | ID: mdl-36137665

ABSTRACT

BACKGROUND AND PURPOSE: West syndrome is a developmental and epileptic encephalopathy characterized by epileptic spasms, neurodevelopmental regression, and a specific EEG pattern called hypsarrhythmia. Our aim was to investigate the brain activities related to hypsarrhythmia at onset and focal epileptiform discharges in the remote period in children with West syndrome using simultaneous electroencephalography and fMRI recordings. MATERIALS AND METHODS: Fourteen children with West syndrome underwent simultaneous electroencephalography and fMRI at the onset of West syndrome. Statistically significant blood oxygen level-dependent responses related to hypsarrhythmia were analyzed using an event-related design of 4 hemodynamic response functions with peaks at 3, 5, 7, and 9 seconds after the onset of each event. Six of 14 children had focal epileptiform discharges after treatment and underwent simultaneous electroencephalography and fMRI from 12 to 25 months of age. RESULTS: At onset, positive blood oxygen level-dependent responses were seen in the brainstem (14/14 patients), thalami (13/14), basal ganglia (13/14), and hippocampi (13/14), in addition to multiple cerebral cortices. Group analysis using hemodynamic response functions with peaks at 3, 5, and 7 seconds showed positive blood oxygen level-dependent responses in the brainstem, thalamus, and hippocampus, while positive blood oxygen level-dependent responses in multiple cerebral cortices were seen using hemodynamic response functions with peaks at 5 and 7 seconds. In the remote period, 3 of 6 children had focal epileptiform discharge-related positive blood oxygen level-dependent responses in the thalamus, hippocampus, and brainstem. CONCLUSIONS: Positive blood oxygen level-dependent responses with hypsarrhythmia appeared in the brainstem, thalamus, and hippocampus on earlier hemodynamic response functions than the cerebral cortices, suggesting the propagation of epileptogenic activities from the deep brain structures to the neocortices. Activation of the hippocampus, thalamus, and brainstem was still seen in half of the patients with focal epileptiform discharges after adrenocorticotropic hormone therapy.


Subject(s)
Spasms, Infantile , Child , Humans , Spasms, Infantile/diagnostic imaging , Magnetic Resonance Imaging , Electroencephalography , Brain Stem/diagnostic imaging , Brain , Hippocampus/diagnostic imaging , Thalamus/diagnostic imaging
5.
AJNR Am J Neuroradiol ; 37(4): 698-705, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26585267

ABSTRACT

BACKGROUND AND PURPOSE: West syndrome is an epileptic encephalopathy characterized by epileptic spasms, a specific pattern on electroencephalography of hypsarrhythmia, and developmental regression. Our aim was to assess white matter abnormalities in West syndrome of unknown etiology. We hypothesized that diffusion tensor imaging reveals white matter abnormalities, especially in patients with poor seizure and developmental outcomes. MATERIALS AND METHODS: We enrolled 23 patients with new-onset West syndrome of unknown etiology. DTI was performed at 12 and 24 months of age. Fractional anisotropy images were compared with those of controls by using tract-based spatial statistics. We compared axial, radial, and mean diffusivity between patients and controls in the fractional anisotropy skeleton. We determined correlations of these parameters with developmental quotient, electroencephalography, and seizure outcomes. We also compared DTI with hypometabolism on fluorodeoxyglucose positron-emission tomography. RESULTS: At 12 months of age, patients showed widespread fractional anisotropy reductions and higher radial diffusivity in the fractional anisotropy skeleton with a significant difference on tract-based spatial statistics. The developmental quotient at 12 months of age correlated positively with fractional anisotropy and negatively with radial and mean diffusivity. Patients with seizure and abnormal findings on electroencephalography after initial treatments had lower fractional anisotropy and higher radial diffusivity. At 24 months, although tract-based spatial statistics did not show significant differences between patients and controls, tract-based spatial statistics in the 10 patients with a developmental quotient of <70 had significant fractional anisotropy reduction. In patients with unilateral temporal lobe hypometabolism on PET, tract-based spatial statistics showed greater fractional anisotropy reduction in the temporal lobe ipsilateral to the side of PET hypometabolism. CONCLUSIONS: Diffuse abnormal findings on DTI at 12 months of age suggest delayed myelination as a key factor underlying abnormal findings on DTI. Conversely, asymmetric abnormal findings on DTI at 24 months may reflect underlying focal pathologies.


Subject(s)
Developmental Disabilities/pathology , Seizures/pathology , Spasms, Infantile/pathology , White Matter/pathology , Adrenocorticotropic Hormone/metabolism , Anisotropy , Developmental Disabilities/etiology , Diffusion Tensor Imaging , Electroencephalography , Female , Fluorodeoxyglucose F18 , Humans , Infant , Male , Positron-Emission Tomography , Radiopharmaceuticals , Seizures/etiology , Spasms, Infantile/diagnostic imaging , Treatment Outcome , White Matter/diagnostic imaging , White Matter/growth & development
6.
Asian J Endosc Surg ; 5(2): 53-8, 2012 May.
Article in English | MEDLINE | ID: mdl-22776364

ABSTRACT

INTRODUCTION: Laparoscopy for small bowel obstruction (SBO) has increasingly been performed for the advantages minimally invasive surgery provides. However, its benefit remains unclear. METHODS: From January 2004 to July 2011, we enrolled 28 consecutive patients who underwent a laparoscopic operation for SBO, secondary to postoperative adhesions. We compared the results of SBO patients treated laparoscopically with those of 25 patients who underwent conventional open laparotomy in a retrospective matched-pair analysis. RESULTS: Laparoscopic treatment was completed in 25 patients (89%), including 17 laparoscopic-assisted cases. The mean procedural time was 112 minutes in the laparoscopic group and 79 minutes in the open group (P < 0.05). Patients resumed oral intake after a mean of 3 days in the laparoscopic group compared with a mean of 6.5 days in the open group (P < 0.05). The length of hospital stay was 11 and 22 days (P < 0.05), respectively, in the laparoscopic and open groups. Postoperative complications occurred in two patients in the laparoscopy group and 14 patients in the open group (P < 0.05). CONCLUSION: The laparoscopic approach was effective for the management of mechanical SBO in selected patients. Furthermore, minimally invasive laparoscopic adhesiolysis is also feasible and brings the benefit of cosmetic results.


Subject(s)
Intestinal Obstruction/surgery , Intestine, Small/surgery , Laparoscopy , Postoperative Complications/surgery , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Intestinal Obstruction/etiology , Intestine, Small/pathology , Laparotomy , Length of Stay/statistics & numerical data , Male , Middle Aged , Operative Time , Postoperative Complications/etiology , Recovery of Function , Retrospective Studies , Tissue Adhesions/etiology , Tissue Adhesions/surgery , Treatment Outcome , Young Adult
7.
Neurogastroenterol Motil ; 20(10): 1174-84, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18631160

ABSTRACT

The objective of this study was to describe the correlation between changes in colonic motility and defecatory disorders in four experimental canine models, with an emphasis on denervation. Therefore, we constructed a model by dividing 20 healthy mongrel dogs into four groups, i.e. control, denervation, transection and anterior resection of the rectum (AR) (denervation plus transection), and focused on the correlation between colonic motility and defecatory disorders by counting the colonic migrating motor complexes (CMMCs) and colonic non-migrating motor complexes (CNMCs). Gastrointestinal and colonic contractile activities were continuously recorded on a computer with strain gauge force transducers. The dogs' feces were checked daily, and their consistency was recorded as normal, semisolid, or watery. Compared with the control group, the transection group showed elongation of the propagation time (P < 0.05), and the mean motility index of colonic contractile activity at C4 and C5 in the denervation group was greater than that in the control group (P < 0.05). The AR group showed three features of colonic motility: (i) elongation of the mean CMMC cycle (P < 0.05); (ii) shortening of the propagation time (P < 0.05); and (iii) increment of the number of CNMCs. Concerning fecal consistency, the AR group only showed watery diarrhoea. In conclusion, we revealed the existence of a correlation between defecatory disorders and changes in colonic motility. Increased knowledge among colorectal surgeons of the changes in colonic motility that occur following colorectal surgery is very important and could lead to the curtailment of defecatory disorders among patients.


Subject(s)
Colon/physiology , Defecation/physiology , Gastrointestinal Motility/physiology , Myoelectric Complex, Migrating/physiology , Rectal Diseases/physiopathology , Rectum/surgery , Animals , Dogs , Humans , Muscle Contraction/physiology , Postprandial Period , Random Allocation , Rectum/innervation
8.
J Clin Pharm Ther ; 32(4): 333-41, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17635335

ABSTRACT

Pharmacogenetic studies have shown that several cytochrome P450 (CYP) enzymes exhibit genetic polymorphisms. Several benzodiazepines (BZPs) are metabolized predominantly or partly by polymorphic CYP2C19 and CYP3A4/5. The pharmacokinetics of diazepam, etizolam, quazepam and desmethylclobazam have been shown to be affected by CYP2C19 polymorphism. The CYP3A5 polymorphism has been reported to affect the pharmacokinetics of alprazolam, but its effect on midazolam kinetics has been inconclusive. For etizolam and desmethylclobazam, some data suggest that CYP2C19 deficiency leads to side-effects or toxicity. For the remaining BZPs the clinical significance of the observed pharmacokinetic changes remains unclear. Further studies on the effects of genetic polymorphisms of CYP enzymes on the pharmacokinetics and pharmacodynamics of BZPs are necessary to guide treatment individualization and optimization.


Subject(s)
Benzodiazepines/pharmacokinetics , Cytochrome P-450 Enzyme System/genetics , Polymorphism, Genetic , Aryl Hydrocarbon Hydroxylases , Benzodiazepines/pharmacology , Cytochrome P-450 CYP2C19 , Cytochrome P-450 CYP3A , Humans , Mixed Function Oxygenases , Pharmacogenetics
9.
Eur J Clin Pharmacol ; 61(11): 791-5, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16261363

ABSTRACT

OBJECTIVE: To examine the effect of cytochrome P450 (CYP) 2C19 activity on the single-dose pharmacokinetics and pharmacodynamics of etizolam. METHODS: The subjects were 21 healthy Japanese volunteers. The two mutated alleles (CYP2C19*2 and CYP2C19*3) causing absent CYP2C19 activity were identified by a polymerase chain reaction method. Twelve subjects were extensive metabolizers (EMs) with no or one mutated allele, and nine subjects were poor metabolizers (PMs) with two mutated alleles. The subjects received a single oral 1-mg dose of etizolam, and blood samplings and evaluation of psychomotor function were conducted up to 24 h after dosing. RESULTS: The PMs had significantly larger total area under the plasma concentration-time curve (287+/-74 vs 178+/-122 ng.h/ml, p<0.05) and longer elimination half-life (14.8+/-4.2 vs 10.5+/-3.9 h, p<0.05) of etizolam than the EMs. The area under the score-time curve from 0 to 8 h of the Stanford Sleepiness Scale was significantly larger in the PMs than in EMs (28.9+/-5.2 vs 22.9+/-6.9 score.h, p<0.05). CONCLUSION: The present study suggests that the single-dose pharmacokinetics and pharmacodynamics of etizolam are influenced by polymorphic CYP2C19 activity.


Subject(s)
Aryl Hydrocarbon Hydroxylases/genetics , Diazepam/analogs & derivatives , Mixed Function Oxygenases/genetics , Psychomotor Performance/drug effects , Tranquilizing Agents/pharmacokinetics , Adult , Alleles , Area Under Curve , Aryl Hydrocarbon Hydroxylases/metabolism , Cytochrome P-450 CYP2C19 , Diazepam/pharmacokinetics , Diazepam/pharmacology , Female , Half-Life , Humans , Japan , Male , Mixed Function Oxygenases/metabolism , Pharmacogenetics , Phenotype , Tranquilizing Agents/pharmacology
10.
Eur J Clin Pharmacol ; 61(3): 185-8, 2005 May.
Article in English | MEDLINE | ID: mdl-15776275

ABSTRACT

OBJECTIVE: To examine the effect of carbamazepine on the single oral dose pharmacokinetics of etizolam. METHODS: Eleven healthy male volunteers received carbamazepine 200 mg/day or placebo for 6 days in a double-blind, randomized, crossover manner, and on the sixth day they received a single oral 1-mg dose of etizolam. Blood samplings and evaluation of psychomotor function by the Digit Symbol Substitution Test and Stanford Sleepiness Scale were conducted up to 24 h after etizolam dosing. Plasma concentration of etizolam was measured using high-performance liquid chromatography. RESULTS: Carbamazepine treatment significantly decreased the peak plasma concentration (17.5+/-4.1 ng/ml versus 13.9+/-4.1 ng/ml; P<0.05), total area under the plasma concentration-time curve (194.8+/-88.9 ng h/ml versus 105.9+/-33.0 ng h/ml; P<0.001), and elimination half-life (11.1+/-4.6 h versus 6.8+/-2.8 h; P<0.01) of etizolam. No significant change was induced by carbamazepine in the two pharmacodynamic parameters. CONCLUSIONS: The present study suggests that carbamazepine induces the metabolism of etizolam.


Subject(s)
Carbamazepine/pharmacology , Diazepam/analogs & derivatives , Administration, Oral , Adult , Analgesics, Non-Narcotic/pharmacology , Area Under Curve , Chromatography, High Pressure Liquid , Cross-Over Studies , Diazepam/administration & dosage , Diazepam/blood , Diazepam/pharmacokinetics , Dose-Response Relationship, Drug , Double-Blind Method , Drug Interactions , Half-Life , Humans , Male , Metabolic Clearance Rate/drug effects , Tranquilizing Agents/administration & dosage , Tranquilizing Agents/metabolism , Tranquilizing Agents/pharmacokinetics
11.
Eur J Clin Pharmacol ; 60(6): 427-30, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15232663

ABSTRACT

OBJECTIVE: To clarify the involvement of cytochrome P450 (CYP) 3A4 in the metabolism of etizolam. METHODS: The effects of itraconazole, a potent and specific inhibitor of CYP3A4, on the single oral dose pharmacokinetics and pharmacodynamics of etizolam were examined. Twelve healthy male volunteers received itraconazole (200 mg/day) or placebo for 7 days in a double-blind randomized crossover manner, and on the 6th day they received a single oral 1-mg dose of etizolam. Blood samplings and evaluation of psychomotor function using the Digit Symbol Substitution Test and Stanford Sleepiness Scale were conducted up to 24 h after etizolam dosing. Plasma concentration of etizolam was measured by means of high-performance liquid chromatography. RESULTS: Itraconazole treatment significantly increased the total area under the plasma concentration-time curve (AUC; 213+/-106 ng rectangle h/ml versus 326+/-166 ng rectangle h/ml, P<0.001) and the elimination half-life (12.0+/-5.4 h versus 17.3+/-7.4 h, P<0.01) of etizolam. The 90% confidence interval of the itraconazole/placebo ratio of the total AUC was 1.38-1.68, indicating a significant effect of itraconazole. No significant change was induced by itraconazole in the two pharmacodynamic parameters. CONCLUSION: The present study suggests that itraconazole inhibits the metabolism of etizolam, providing evidence that CYP3A4 is at least partly involved in etizolam metabolism.


Subject(s)
Antifungal Agents/pharmacology , Cytochrome P-450 Enzyme System/metabolism , Diazepam/analogs & derivatives , Diazepam/antagonists & inhibitors , Diazepam/pharmacokinetics , Itraconazole/pharmacology , Tranquilizing Agents/antagonists & inhibitors , Tranquilizing Agents/pharmacokinetics , Adult , Area Under Curve , Chromatography, High Pressure Liquid , Cross-Over Studies , Cytochrome P-450 CYP3A , Diazepam/blood , Double-Blind Method , Drug Interactions , Half-Life , Humans , Male , Tranquilizing Agents/blood
12.
Article in English | MEDLINE | ID: mdl-11513361

ABSTRACT

There has been few reports on the effective treatment for SOD, which is phenomenologically similar to TD. A 66-year-old female with SOD was successfully treated by CNZ 2 mg/day. Even after one year of continuous treatment, tolerance, which is the major problem in the CNZ treatment for TD, did not develop. This report suggests that CNZ is effective at least for some patients with SOD.


Subject(s)
Anticonvulsants/therapeutic use , Clonazepam/therapeutic use , Dyskinesia, Drug-Induced/drug therapy , Aged , Drug Tolerance , Dyskinesia, Drug-Induced/physiopathology , Female , Humans
13.
Biochem Biophys Res Commun ; 285(3): 696-701, 2001 Jul 20.
Article in English | MEDLINE | ID: mdl-11453649

ABSTRACT

Heat shock factor Hsf1 of the yeast Saccharomyces cerevisiae binds to the heat shock element (HSE) of a subset of genes and activates their transcription in response to various environmental stresses. Hsf1 protein contains discrete domains respectively involved in DNA-binding, trimerization, transcription activation, and transcription repression. Here we have identified a novel domain rich in basic amino acids at the extreme C-terminus of Hsf1. Deletion or point mutations of the C-terminal basic region caused an inefficient heat shock response of genes containing noncanonical HSEs such as CUP1 and HSP26. The basic region is also essential for oxidative stress-inducible transcription of CUP1 by Hsf1. By contrast, it was dispensable for heat induction through the canonical HSE. We suggest that the basic region is a modulator involved in regulation of the Hsf1-mediated activation depending on the architecture of its binding site.


Subject(s)
DNA-Binding Proteins/metabolism , Heat-Shock Proteins/metabolism , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/metabolism , Transcription Factors/metabolism , Amino Acid Motifs/physiology , Carrier Proteins , DNA-Binding Proteins/genetics , Enhancer Elements, Genetic/physiology , Fungal Proteins/genetics , Fungal Proteins/metabolism , Gene Expression Regulation/physiology , Heat-Shock Proteins/genetics , Heat-Shock Response/physiology , Metallothionein/genetics , Mutagenesis, Site-Directed , Oxidative Stress/physiology , Protein Structure, Tertiary/physiology , Saccharomyces cerevisiae/genetics , Substrate Specificity/genetics , Transcription Factors/genetics , Transcriptional Activation/physiology
14.
Clin Exp Dermatol ; 26(2): 201-4, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11298116

ABSTRACT

A 65-year-old Japanese woman presented with disseminated erythematous patches, plaques, and nodules on the trunk and limbs. Histological examination showed diffuse and dense infiltrates located in the dermis and subcutis, composed of large pleomorphic T lymphocytes. Immunohistochemically, neoplastic cells were positive for blastic T-cell markers, but negative for CD30 (Ki-1) antigen. Based on the clinicopathological findings, a diagnosis of primary cutaneous large T-cell lymphoma was made. Despite systemic chemotherapy, the patient died 7 months after diagnosis. Gene expression profiling using complementary DNA microarrays indicated significantly increased expression of an apoptosis-inhibitory protein and certain cyokines and cytokine receptors (e.g. MCP-1, MCP-2, IP-10, and IL-2R gamma) in the tumour-indurated skin. Comprehensive gene expression patterning in additional cases may provide useful information regarding the biological and clinical behaviour of aggressive cutaneous lymphomas such as CD30-negative large T-cell lymphoma.


Subject(s)
Cytokines/genetics , Intracellular Signaling Peptides and Proteins , Lymphoma, T-Cell, Cutaneous/genetics , Receptors, Cytokine/genetics , Skin Neoplasms/genetics , Aged , CASP8 and FADD-Like Apoptosis Regulating Protein , Carrier Proteins/genetics , Chemokine CCL2/genetics , Chemokine CCL8 , Chemokine CXCL10/genetics , Female , Gene Expression , Humans , Ki-1 Antigen , Lymphoma, T-Cell, Cutaneous/diagnosis , Monocyte Chemoattractant Proteins/genetics , Proliferating Cell Nuclear Antigen/genetics , Skin Neoplasms/diagnosis
15.
DNA Res ; 8(1): 23-31, 2001 Feb 28.
Article in English | MEDLINE | ID: mdl-11258797

ABSTRACT

The Gal11 protein is a subunit of the Mediator complex. Biochemical as well as genetic studies have strongly suggested that Gal11 is a positive global regulator of transcription. Some reports argue that Gal11 is a negative regulator, however. Here we have adopted the "Mini-array membrane hybridization" to analyze the effect of Gal11 in a genome-wide fashion. This technique has been demonstrated to be reliable to identify genes whose expression is controlled by a specific set of genetic and/or physiological signals. Our experiments indicate that this technique is applicable to profile the gene expression in yeast grown in rich medium. Thus mRNAs of 40% of significantly expressed genes are reduced more than two fold in gal11null yeast, in which only 3% of mRNAs are increased more than two fold. These results strongly suggest that Gal11 functions globally as a positive regulator in vivo.


Subject(s)
Fungal Proteins/metabolism , Gene Expression Profiling/methods , Oligonucleotide Array Sequence Analysis/methods , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/genetics , Trans-Activators/metabolism , Gene Expression Regulation, Fungal , Mediator Complex , Nucleic Acid Hybridization , RNA, Fungal/isolation & purification , RNA, Messenger/isolation & purification , Transcription, Genetic
16.
Pancreas ; 22(2): 135-40, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11249067

ABSTRACT

We characterized morphologic and secretory properties of porcine pancreatic endocrine cells in primary culture obtained by autolytic preparation without any exogenous proteolytic enzymes. The endocrine cells exhibited a neuron-like shape, and insulin granules were accumulated at the terminal of the processes. Thus derived endocrine cells survived in culture medium containing nicotinamide and remained sensitive to glucose for at least 6 weeks after preparations. The cells responded well to physiologic concentrations of glucose, and high K+ depolarization and the antidiabetic sulfonylureas, tolbutamide, and glibenclamide also elicited the release. With high glucose, insulin release was markedly potentiated by forskolin, glucagon, glucagon-like peptide-1, and arginine and inhibited by somatostatin, the Ca2+ channel blocker nitrendipine, and the ATP-sensitive K+ channel opener diazoxide. Epinephrine had dual effects on the release by glucose; enhanced within a low nanomolar range and inhibited at 1 micromol/L. However, the cells were unresponsive to leucine. Such secretory sensitivities to nutrients, hormones, and pharmacologic agents, and long survival rate (as long as 5-6 weeks) of these cells suggest to us therefore that derived endocrine cells may be useful for xenotransplantation of pancreatic beta cells for treatment of insulin-dependent diabetes mellitus.


Subject(s)
Insulin/metabolism , Islets of Langerhans/cytology , Animals , Cells, Cultured , Epinephrine/pharmacology , Glucose/pharmacology , Insulin Secretion , Islets of Langerhans/metabolism , Nitrendipine/pharmacology , Swine , Yohimbine/pharmacology
17.
Jpn J Cancer Res ; 91(12): 1241-9, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11123422

ABSTRACT

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. Since c-kit mutation occurs only in one-third of GIST, there might be other molecular mechanisms. Loss of heterozygosity (LOH), microsatellite instability (MSI) and NF2 gene mutation were investigated in 22 GISTs (9 low-risk and 13 high-risk tumors). LOH and MSI were evaluated using 41 markers on 21 chromosomal arms, and NF2 gene mutation was examined by PCR-SSCP. High frequency of LOH was observed on 14q (9 / 19, 47%), and 22q (17 / 22, 77%). The frequencies were similar in low-risk and high-risk tumors, and were unrelated with gastric or intestinal origin. Two other abnormalities, additional LOH on other chromosomes and MSI at more than two loci, were characteristic of the high-risk tumors (P < 0.05). NF2 gene mutation was identified in two cases showing 22q-LOH (8 bp deletion on the splice donor site of exon 7, and 1 bp insertion at position 432 of exon 4, which resulted in nonsense mutation). There was no significant correlation between these results and c-kit gene mutation, which was observed in 8 of 22 tumors. Suppressor genes on 14q and 22q may be involved, independently of c-kit gene mutation, in the development of GIST. NF2 contributes as a tumor suppressor in a small subset of GIST. These abnormalities are presumably followed by increased genetic instability.


Subject(s)
Chromosome Mapping , Chromosomes, Human, Pair 14 , Chromosomes, Human, Pair 22 , Gastrointestinal Neoplasms/genetics , Genes, Neurofibromatosis 2 , Loss of Heterozygosity , Membrane Proteins/genetics , Proto-Oncogene Proteins c-kit/genetics , Adult , Aged , Exons , Female , Genetic Markers , Humans , Intestinal Neoplasms/genetics , Male , Microsatellite Repeats , Middle Aged , Mutation, Missense , Neurofibromin 2 , Polymerase Chain Reaction , Polymorphism, Single-Stranded Conformational , Stomach Neoplasms/genetics
18.
J Biol Chem ; 275(47): 37251-6, 2000 Nov 24.
Article in English | MEDLINE | ID: mdl-10973956

ABSTRACT

The yeast Gal11 protein is an important component of the Mediator complex in RNA polymerase II-directed transcription. Gal11 and the general transcription factor (TF) IIE are involved in regulation of the protein kinase activity of TFIIH that phosphorylates the carboxyl-terminal domain of RNA polymerase II. We have previously shown that Gal11 binds the small and large subunits of TFIIE at two Gal11 domains, A and B, respectively, which are important for normal function of Gal11 in vivo. Here we demonstrate that Gal11 binds directly to TFIIH through domain A in vitro. A null mutation in GAL11 caused lethality of cells when combined with temperature-sensitive mutations in the genes encoding TFIIE or the carboxyl-terminal domain kinase, indicating the presence of genetic interactions between Gal11 and these proteins. Mutational depletion of Gal11 or TFIIE caused inefficient opening of the transcription initiation region, but had no significant effect on TATA-binding protein occupancy of the TATA sequence in vivo. These results suggest that the functions of Gal11 and TFIIE are necessary after recruitment of TATA-binding protein to the TATA box presumably at the step of stable preinitiation complex formation and/or promoter melting. We illustrate genetic interactions between Gal11 and other Mediator components such as Med2 and Pgd1/Hrs1/Med3.


Subject(s)
Fungal Proteins/physiology , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/physiology , TATA-Binding Protein Associated Factors , Trans-Activators/physiology , Transcription Factor TFIID , Transcription Factors, TFII , Transcription Factors/physiology , Base Sequence , Chromatography, Affinity , DNA-Binding Proteins/metabolism , Mediator Complex , Molecular Sequence Data , TATA-Box Binding Protein , Transcription Factor TFIIH , Transcription Factors/metabolism
19.
FEBS Lett ; 479(1-2): 46-50, 2000 Aug 11.
Article in English | MEDLINE | ID: mdl-10940386

ABSTRACT

The aim of this study was to investigate possible involvement of annexin XI in the insulin secretory machinery. In fluorescence immunocytochemistry, annexin XI was found in the cytoplasm of pancreatic endocrine cells and a pancreatic beta-cell line, MIN6, in a granular pattern. MIN6 cells also possessed weak and diffused annexin XI immunoreactivity in the cytoplasm. Immunoelectron microscopy revealed annexin XI in the insulin granules. Insulin secretion from streptolysin-O-permeabilized MIN6 cells was inhibited by anti-annexin XI antibody, when the release was stimulated by either Ca2+ or GTP-gammaS, but not by a protein kinase C-activating phorbol ester. Inhibition of insulin release by anti-annexin XI antibody was reproduced in permeabilized rat islets. These findings suggest that annexin XI may be involved in the regulation of insulin secretion from the pancreatic beta-cells.


Subject(s)
Annexins/physiology , Calcium/pharmacology , Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology , Insulin/metabolism , Islets of Langerhans/drug effects , Islets of Langerhans/metabolism , Animals , Cell Line , Immunohistochemistry , In Vitro Techniques , Insulin Secretion , Islets of Langerhans/physiology , Male , Mice , Microscopy, Immunoelectron , Rats , Rats, Wistar
20.
Diabetes ; 49(6): 945-52, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10866046

ABSTRACT

Protein phosphorylation by myosin light-chain kinase (MLCK), protein kinase A, and protein kinase C (PKC) plays a positive role in insulin secretion from the pancreatic beta-cell. To investigate the underlying mechanisms, we examined intracellular distribution of the insulin granules and MLCK by immunofluorescence and immunoelectron microscopies and also investigated intracellular traffic of the granules in cultured beta-cells (MIN6) by video microscopy. Considerable parts of MLCK immunoreactivity were colocalized with the insulin granules. Subcellular fractionation of MIN6 cell extracts revealed that myosin light chain (MLC) may be distributed with the insulin-rich fractions, and immunofluorescence staining using specific antibodies against mono- and diphosphorylated MLCs depicted presence of phosphorylated MLCs in the cytoplasm, in part, with colocalization with the insulin granules. Activation of PKC by 12-O-tetradecanoyl-phorbol 13-acetate (TPA) caused a shift of both insulin granules and MLCK to the cell periphery, which was not reproduced by the adenylate cyclase activator, forskolin. In contrast, forskolin, but not TPA, increased the granule movement. Costimulation of the beta-cell by TPA and forskolin induced drastic translocation of insulin granules and MLCK to the cell periphery, resulting in enormous potentiation of insulin release. These findings suggest that these protein kinases increase insulin granules in the ready-releasable pool by acting on different steps in the secretory cascade.


Subject(s)
Cyclic AMP-Dependent Protein Kinases/metabolism , Islets of Langerhans/metabolism , Myosin-Light-Chain Kinase/metabolism , Protein Kinase C/metabolism , Cell Line , Colforsin/pharmacology , Cytoplasmic Granules/metabolism , Drug Synergism , Insulin/metabolism , Insulin Secretion , Intracellular Membranes/metabolism , Myosin Light Chains/metabolism , Phosphorylation , Subcellular Fractions/metabolism , Tetradecanoylphorbol Acetate/pharmacology , Tissue Distribution
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