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1.
Saudi Med J ; 45(4): 437-441, 2024 Apr.
Article En | MEDLINE | ID: mdl-38657980

OBJECTIVES: To investigate differences in the incidence of enteropathy or intestinal malabsorption in patients taking angiotensin II receptor blockers (ARBs), angiotensin-converting enzyme inhibitor (ACEI), calcium channel blocker (CCB), and beta blockers (BBs) at a single center in Korea. METHODS: In this retrospective study, we utilized data from the Yangsan electronic medical records to identify 129,169 patients. These individuals were prescribed olmesartan, other ARBs, ACEI, CCB, and BBs between November 2008 and February 2021. RESULTS: Of the 44,775 patients, 51 (0.11%) were observed to have enteropathy or intestinal malabsorption. Compared with the ACEI group, the adjusted odds ratios (ORs) for enteropathy and intestinal malabsorption were OR=1.313 (95% confidence interval [CI]: [0.188-6.798], p=0.893) for olmesartan, OR=0.915 (95% CI: [0.525-1.595], p=0.754) for the other ARBs, OR=0.928 (95% CI: [0.200-4.307]; p=0.924) for the CCB, and OR=0.663 (95% CI: [0.151-2.906]; p=0.586) for the BBs group. These findings were adjusted for factors such as age, gender, duration of antihypertensive medication, and comorbidities. CONCLUSION: In a retrospective cohort study of patients on antihypertensive medications, no significant difference was found in the incidence of enteropathy or intestinal malabsorption when ACEI was compared to olmesartan, other ARBs, CCB, and BBs.


Angiotensin Receptor Antagonists , Angiotensin-Converting Enzyme Inhibitors , Antihypertensive Agents , Calcium Channel Blockers , Malabsorption Syndromes , Humans , Retrospective Studies , Male , Female , Middle Aged , Malabsorption Syndromes/epidemiology , Malabsorption Syndromes/complications , Antihypertensive Agents/therapeutic use , Aged , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Angiotensin Receptor Antagonists/therapeutic use , Angiotensin Receptor Antagonists/adverse effects , Calcium Channel Blockers/therapeutic use , Intestinal Diseases/epidemiology , Adrenergic beta-Antagonists/therapeutic use , Adrenergic beta-Antagonists/adverse effects , Imidazoles/therapeutic use , Imidazoles/adverse effects , Tetrazoles/therapeutic use , Incidence , Adult , Republic of Korea/epidemiology , Cohort Studies , Hypertension/drug therapy , Hypertension/epidemiology
2.
Laryngoscope ; 2024 Feb 23.
Article En | MEDLINE | ID: mdl-38390693

OBJECTIVE: Tracheal resection (TR) and cricotracheal resection (CTR) are performed for patients with airway stenosis, tracheal tumor, and tracheoesophageal fistula. Post-operative complications include airway edema requiring reintubation, hematoma, anastomotic dehiscence, restenosis, and death. Although these complications and associated risk factors have been well described, the time where clinical suspicion should be highest post operatively has not been characterized. METHODS: Patients who underwent TR or CTR at a single center between 2015 and 2022 were reviewed. Variables including demographics and comorbidities were recorded. Rate, nature, and time in days of post-operative complications were evaluated. RESULTS: Sixty-nine cases were reviewed. Average patient age was 46.8 years old and 63.8% were male. The average follow-up period was 625 ± 724 days. 19 (27.5%) patients experienced one or more major complications including four (5.8%) who died. Eight (11.6%) patients required reintubation and 4 (5.8%) patients underwent revision tracheostomy. Most complications occurred within 8 days of surgery. Restenosis was noted an average of 42.6 days after surgery, with no new restenosis occurring after 3 months. CONCLUSIONS: In this single-center study, most post-operative complications after TR or CTR, including hematoma and anastomotic dehiscence, occurred within 8 days post-operatively. Restenosis was noted approximately 1-3 months after surgery. This may inform clinical decision-making regarding patient monitoring and surveillance after open airway surgery. LEVEL OF EVIDENCE: 4 Laryngoscope, 2024.

3.
Laryngoscope Investig Otolaryngol ; 8(6): 1685-1691, 2023 Dec.
Article En | MEDLINE | ID: mdl-38130243

Objective: To evaluate the quality of thyroidectomy-related posts on TikTok, the fastest-growing social media platform worldwide. Methods: Videos posted from April 2020 to September 2022 were queried on TikTok using the search terms "thyroidsurgery," "thyroidectomy," and "thyroidremoval." Two reviewers recorded thematic, demographic, and performance data of these posts. The DISCERN instrument was used to evaluate the quality and reliability of the information contained in the videos. Descriptive statistics were used to characterize post-submitter demographics and video content. Simple and multiple linear regression analyses were used to evaluate the association between DISCERN scores and video characteristics. Univariate analysis of variance was performed to compare DISCERN scores between author types. Results: In this study, 228 TikTok videos were included which totaled over 23 million views. On average, each video accumulated more than 6000 "likes," 300 comments, and 70 shares. The average total DISCERN score was 27.46, which is deemed to be of poor overall quality. Upon multiple linear regression, video duration (ß = 4.66, p < .001) and educational subject type (ß = 3.97, p < .001) significantly positively predicted aggregate DISCERN scores, while journey subject type (ß = -3.19, p = .006), and reassurance subject type (ß = -2.52, p = .035) significantly negatively predicted aggregate DISCERN scores. Aggregate DISCERN scores varied significantly (p < .05) between author types. Conclusion: Social media posts on TikTok about thyroidectomy are mostly of poor quality and reliability but vary by authorship, subject type, and video characteristics. Given its widespread popularity, TikTok videos may have an increasing role in shaping patient perception of thyroidectomy and may represent an opportunity to provide education. Lay summary: TikTok posts about thyroidectomy are mostly of poor quality but vary by authorship, subject, and video characteristics. Given its popularity, TikTok videos may have a role in shaping the patient perception of thyroidectomy and may represent an opportunity to provide education. Level of evidence: Level 4.

4.
J Public Health (Oxf) ; 45(3): e510-e517, 2023 08 28.
Article En | MEDLINE | ID: mdl-37122205

BACKGROUND: Considering the prolongation of the COVID-19 pandemic, the lack of studies on burnout, particularly in healthcare workers, needs to be addressed. This report aimed to identify the risk factors of burnout by comparing the level of burnout between nurses in general wards and those in COVID-19-dedicated wards in a national university hospital. METHODS: A survey based on the Korean version of Burnout Assessment Tool (BAT-K) was conducted on nurses between 10 January and 31 January 2022. The BAT-K consists of exhaustion, mental distance, cognitive impairment, emotional impairment and secondary symptoms. RESULTS: A total of 165 nurses, including 81 nurses from the COVID-19-dedicated ward, completed the questionnaire. The percentage of general-ward nurses with an emotional impairment score above the clinical cutoff was higher than that of COVID-19 ward nurses. General ward compared to the COVID-19 ward increased the risk of presenting with total-core symptoms. Two factors increased the risk regarding mental distance: short career length and underlying disease. CONCLUSIONS: In contrast to previous studies, the risk of burnout in the COVID-19-ward nurses was lower than that of the general ward nurses. The risk regarding mental distance was correlated with short career length and presence of an underlying disease.


Burnout, Professional , COVID-19 , Humans , COVID-19/epidemiology , Pandemics , Burnout, Professional/epidemiology , Burnout, Professional/psychology , Health Personnel/psychology , Hospitals, University , Surveys and Questionnaires
5.
Neurobiol Aging ; 49: 217.e1-217.e4, 2017 01.
Article En | MEDLINE | ID: mdl-27814993

A recent study MacLeod et al. has shown that an interaction between variants at the LRRK2 and PARK16 loci influences risk of development of Parkinson's disease (PD). Our study examines the proposed interaction between LRRK2 and PARK16 variants in modifying PD risk using a large multicenter series of PD patients (7715) and controls (8261) from sites participating in the Genetic Epidemiology of Parkinson's Disease Consortium. Our data does not support a strong direct interaction between LRRK2 and PARK16 variants; however, given the role of retromer and lysosomal pathways in PD, further studies are warranted.


Epistasis, Genetic/genetics , Genetic Association Studies , Genetic Loci/genetics , Genetic Predisposition to Disease/genetics , Genetic Variation/genetics , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/genetics , Multicenter Studies as Topic , Parkinson Disease/genetics , Humans , Risk
6.
Neurology ; 85(15): 1283-92, 2015 Oct 13.
Article En | MEDLINE | ID: mdl-26354989

OBJECTIVES: We aim to clarify the pathogenic role of intermediate size repeat expansions of SCA2, SCA3, SCA6, and SCA17 as risk factors for idiopathic Parkinson disease (PD). METHODS: We invited researchers from the Genetic Epidemiology of Parkinson's Disease Consortium to participate in the study. There were 12,346 cases and 8,164 controls genotyped, for a total of 4 repeats within the SCA2, SCA3, SCA6, and SCA17 genes. Fixed- and random-effects models were used to estimate the summary risk estimates for the genes. We investigated between-study heterogeneity and heterogeneity between different ethnic populations. RESULTS: We did not observe any definite pathogenic repeat expansions for SCA2, SCA3, SCA6, and SCA17 genes in patients with idiopathic PD from Caucasian and Asian populations. Furthermore, overall analysis did not reveal any significant association between intermediate repeats and PD. The effect estimates (odds ratio) ranged from 0.93 to 1.01 in the overall cohort for the SCA2, SCA3, SCA6, and SCA17 loci. CONCLUSIONS: Our study did not support a major role for definite pathogenic repeat expansions in SCA2, SCA3, SCA6, and SCA17 genes for idiopathic PD. Thus, results of this large study do not support diagnostic screening of SCA2, SCA3, SCA6, and SCA17 gene repeats in the common idiopathic form of PD. Likewise, this largest multicentered study performed to date excludes the role of intermediate repeats of these genes as a risk factor for PD.


Gene Frequency/genetics , Genetic Predisposition to Disease , Parkinson Disease/genetics , Peptides/genetics , Trinucleotide Repeat Expansion/genetics , Aged , Ataxins/genetics , Ataxins/metabolism , Female , Humans , Male , Middle Aged , Nerve Tissue Proteins/genetics , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Parkinson Disease/epidemiology , Phenotype , Risk
7.
Basic Clin Pharmacol Toxicol ; 113(5): 329-38, 2013 Nov.
Article En | MEDLINE | ID: mdl-23826964

Brefeldin A induces apoptosis in various cancer cells; however, the apoptotic process in cancer cells exposed to brefeldin A remains unclear. In addition, it is unclear whether brefeldin A-induced apoptosis is mediated by the formation of reactive oxygen species. Furthermore, the effect of brefeldin A on the invasion and migration of human epithelial ovarian cancer cells has not been studied. Therefore, we investigated the effect of brefeldin A on apoptosis, cell adhesion and migration using the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. The results suggest that brefeldin A may induce apoptotic cell death in ovarian carcinoma cell lines by activating the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The apoptotic effect of brefeldin A seems to be mediated by formation of reactive oxygen species and depletion of GSH, which results in the activation of apoptotic caspases. Brefeldin A inhibited foetal bovine serum-induced adhesion and migration of OVCAR-3 cells. Brefeldin A may prevent the foetal bovine serum-induced cell adhesion and migration by limiting the focal adhesion kinase-dependent activation of cytoskeletal-associated components.


Apoptosis/drug effects , Brefeldin A/pharmacology , Focal Adhesion Protein-Tyrosine Kinases/antagonists & inhibitors , Mitochondria/drug effects , BH3 Interacting Domain Death Agonist Protein/genetics , BH3 Interacting Domain Death Agonist Protein/metabolism , Carcinoma, Ovarian Epithelial , Caspase 8/genetics , Caspase 8/metabolism , Cell Adhesion/drug effects , Cell Line, Tumor , Cell Movement/drug effects , Cell Survival/drug effects , Cytochromes c/metabolism , DNA Damage/drug effects , DNA Fragmentation/drug effects , Focal Adhesion Protein-Tyrosine Kinases/genetics , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Humans , Membrane Potential, Mitochondrial , Mitochondria/metabolism , Neoplasms, Glandular and Epithelial , Ovarian Neoplasms , Reactive Oxygen Species/metabolism
8.
Basic Clin Pharmacol Toxicol ; 111(3): 173-81, 2012 Sep.
Article En | MEDLINE | ID: mdl-22433057

Hsp90 inhibitor geldanamycin and parthenolide have been shown to induce apoptosis in cancer cells. However, the combined effect of geldanamycin and parthenolide on epithelial ovarian cancer cells has not been studied. In respect of cell death process, we investigated the promoting effect of parthenolide on geldanamycin-induced apoptosis in the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. Geldanamycin induced a decrease in Bid, Bcl-2, Bcl-xL and survivin protein levels; an increase in Bax and tumour suppressor p53 levels; loss of the mitochondrial transmembrane potential; cytochrome c release; activation of caspases (-8, -9 and -3); cleavage of PARP-1; and increase in the reactive oxygen species formation. Parthenolide enhanced geldanamycin-induced changes in the apoptosis-related protein levels, reactive oxygen species formation, nuclear damage and cell death. The combined effect was inhibited by the addition of oxidant scavengers. The results suggest that parthenolide may potentiate the apoptotic effect of geldanamycin on ovarian carcinoma cell lines by the activation of the caspase-8- and Bid-dependent pathway and the mitochondria-mediated apoptotic pathway. The apoptosis-promoting effect seems to be mediated by the stimulatory effect on the formation of reactive oxygen species.


Apoptosis/drug effects , Benzoquinones/pharmacology , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Lactams, Macrocyclic/pharmacology , Reactive Oxygen Species/metabolism , Sesquiterpenes/pharmacology , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Blotting, Western , Carcinoma, Ovarian Epithelial , Caspase 3/genetics , Caspase 3/metabolism , Caspase 8/genetics , Caspase 8/metabolism , Caspase 9/genetics , Caspase 9/metabolism , Cell Line, Tumor , Cell Survival/drug effects , Cytochromes c/genetics , Cytochromes c/metabolism , Female , HSP90 Heat-Shock Proteins/metabolism , Humans , Mitochondria/drug effects , Mitochondria/metabolism , Neoplasms, Glandular and Epithelial/pathology , Ovarian Neoplasms/pathology , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , bcl-2-Associated X Protein/genetics , bcl-2-Associated X Protein/metabolism
9.
Basic Clin Pharmacol Toxicol ; 109(4): 283-91, 2011 Oct.
Article En | MEDLINE | ID: mdl-21554547

To assess the ability of 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1) to promote apoptosis, we investigated the effect of YC-1 on tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in the human epithelial ovarian carcinoma cell lines. In OVCAR-3 and SK-OV-3 cell lines, we examined the stimulatory effect of YC-1 on TRAIL-induced apoptosis by monitoring cell death, nuclear damage, changes in apoptosis-related protein levels, activation of caspases and changes in the mitochondrial transmembrane potential. TRAIL induced a decrease in Bid, Bcl-2 and Bcl-xL protein levels, increase in cleaved Bid and Bax levels, loss of the mitochondrial transmembrane potential, cytochrome c release, activation of caspases (-8, -9 and -3) and an increase in the tumour suppressor p53 levels. YC-1 enhanced TRAIL-induced apoptosis-related protein activation, nuclear damage and cell death. Results from this study suggest that YC-1 may enhance the apoptotic effect of TRAIL on ovarian carcinoma cell lines by increasing the activation of the caspase-8- and Bid-dependent pathways and the mitochondria-mediated apoptotic pathway, leading to caspase activation. YC-1 may confer a benefit in TRAIL treatment of epithelial ovarian adenocarcinoma.


Apoptosis/drug effects , Enzyme Activators/pharmacology , Guanylate Cyclase/metabolism , Indazoles/pharmacology , Ovarian Neoplasms/drug therapy , TNF-Related Apoptosis-Inducing Ligand/pharmacology , Biomarkers, Tumor , Caspase 8/metabolism , Cell Line, Tumor , Female , Humans , Membrane Potential, Mitochondrial/drug effects , Microtubule-Associated Proteins , Neoplasm Proteins , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology
10.
FEBS J ; 276(7): 1952-61, 2009 Apr.
Article En | MEDLINE | ID: mdl-19250319

Galactosemia is caused by defects in the galactose metabolic pathway, which consists of three enzymes, including UDP-galactose-4-epimerase (GALE). We previously reported nine mutations in Korean patients with epimerase-deficiency galactosemia. In order to determine the functional consequences of these mutations, we expressed wild-type and mutant GALE proteins in 293T cells. GALE(E165K) and GALE(W336X) proteins were unstable, had reduced half-life, formed aggregates and were partly degraded by the proteasome complex. When expressed in GALE-null ldlD cells GALE(E165K), GALE(R239W), GALE(G302D) and GALE(W336X) had no detectable enzyme activity, although substantial amounts of protein were detected in western blots. The relative activities of other mutants were lower than that of wild-type. In addition, unlike wild-type, GALE(R239W) and GALE(G302D) were not able to rescue galactose-sensitive cell proliferation when stably expressed in ldlD cells. The four inactive mutant proteins did not show defects in dimerization or affect the activity of other mutant alleles identified in patients. Our observations show that altered protein stability is due to misfolding and that loss or reduction of enzyme activity is responsible for the molecular defects underlying GALE-deficiency galactosemia.


Galactosemias/enzymology , Galactosemias/genetics , Mutation , UDPglucose 4-Epimerase/genetics , Cell Proliferation , Cells, Cultured , DNA, Complementary/genetics , DNA, Complementary/metabolism , Dimerization , Galactosemias/metabolism , Humans , Korea , Lymphocytes, Null/metabolism , Microscopy, Fluorescence , Transfection , UDPglucose 4-Epimerase/metabolism
11.
Neurobiol Dis ; 22(2): 346-56, 2006 May.
Article En | MEDLINE | ID: mdl-16423528

N-terminal mutant huntingtin (N-mhtt) fragments form inclusions and cause cell death in vitro. Mutant htt expression stimulates autophagy and increases levels of lysosomal proteases. Here, we show that lysosomal proteases, cathepsins D, B and L, affected mhtt processing and levels of cleavage products (cp) known as A and B, which form inclusions. Adding inhibitors of cathepsin D, B and L to clonal striatal cells reduced mhtt, especially mhtt fragment cp A. Mutant htt fully degraded in cathepsin-L-treated lysates but formed stable N-mhtt fragments upon exposure to cathepsin D. Mutagenesis analysis of htt cDNA suggested that cathepsin D and the protease for cp A may cleave htt in the same region. Brain lysates from HD knock-in mice expressed N-mhtt fragments that accumulated with cathepsin D treatment and declined with aspartyl protease inhibition. Findings implicate lysosomal proteases in formation of N-mhtt fragments and clearance of mhtt.


Cathepsins/metabolism , Huntington Disease/enzymology , Lysosomes/enzymology , Nerve Tissue Proteins/metabolism , Nuclear Proteins/metabolism , Peptide Fragments/metabolism , Peptide Hydrolases/metabolism , Animals , Aspartic Acid Endopeptidases/antagonists & inhibitors , Aspartic Acid Endopeptidases/metabolism , Binding Sites/physiology , Cathepsin D/antagonists & inhibitors , Cathepsin D/metabolism , Cathepsins/antagonists & inhibitors , Cell Line, Transformed , Corpus Striatum/enzymology , Corpus Striatum/pathology , Corpus Striatum/physiopathology , Enzyme Inhibitors/pharmacology , Huntingtin Protein , Huntington Disease/genetics , Huntington Disease/physiopathology , Mice , Mice, Inbred C57BL , Mice, Neurologic Mutants , Mice, Transgenic , Mutation/genetics , Nerve Tissue Proteins/chemistry , Nerve Tissue Proteins/genetics , Neurons/enzymology , Neurons/pathology , Nuclear Proteins/chemistry , Nuclear Proteins/genetics , Peptide Hydrolases/drug effects , Protein Structure, Tertiary/physiology
12.
J Biol Chem ; 280(43): 36464-73, 2005 Oct 28.
Article En | MEDLINE | ID: mdl-16085648

We have identified a domain in the N terminus of huntingtin that binds to membranes. A three-dimensional homology model of the structure of the binding domain predicts helical HEAT repeats, which emanate a positive electrostatic potential, consistent with a charge-based mechanism for membrane association. An amphipathic helix capable of inserting into pure lipid bilayers may serve to anchor huntingtin to the membrane. In cells, N-terminal huntingtin fragments targeted to regions of plasma membrane enriched in phosphatidylinositol 4,5-bisphosphate, receptor bound-transferrin, and endogenous huntingtin. N-terminal huntingtin fragments with an expanded polyglutamine tract aberrantly localized to intracellular regions instead of plasma membrane. Our data support a new model in which huntingtin directly binds membranes through electrostatic interactions with acidic phospholipids.


Cell Membrane/metabolism , Nerve Tissue Proteins/physiology , Nuclear Proteins/physiology , Phospholipids/chemistry , Amino Acid Sequence , Animals , Blotting, Western , COS Cells , Calorimetry, Differential Scanning , Cell Line, Tumor , Chlorocebus aethiops , DNA, Complementary/metabolism , Endoplasmic Reticulum/metabolism , Glutathione Transferase/metabolism , Humans , Huntingtin Protein , Immunohistochemistry , Immunoprecipitation , Lipid Bilayers/chemistry , Microscopy, Fluorescence , Models, Molecular , Molecular Sequence Data , Mutation , Nerve Tissue Proteins/chemistry , Nuclear Proteins/chemistry , Peptides/chemistry , Phosphatidylinositol 4,5-Diphosphate/chemistry , Protein Binding , Protein Structure, Tertiary , Recombinant Fusion Proteins/metabolism , Software , Static Electricity , Subcellular Fractions , Temperature , Transfection , Transferrin/chemistry
13.
Ann Nucl Med ; 18(7): 609-16, 2004 Oct.
Article En | MEDLINE | ID: mdl-15586635

UNLABELLED: The objective of this study was to evaluate the reproducibility of 123I-FPCIT SPECT by using whole striatal region of interest (ROI) and subdivided ROI in normal controls (NC) and Parkinson's disease (PD) patients. METHODS: Ten NC and 6 PD received a SPECT scan for 6 hours postinjection of FPCIT. The distribution volume ratio (R(V)) and specific-nonspecific tissue activity ratio (RT) were measured as an outcome measure. The test/retest reproducibility of R(V) and R(T) was evaluated by calculating the test/retest difference, variability, and reliability. RESULTS: There were no significant test/retest differences for any regions in either the NC or PD. The test/retest variability/reliability of Rv was 5.53+/-4.12%/0.89 in NC, 4.50+/-5.31%/0.99 in PD with whole striatal ROI, 4.29+/-0.78%/ 0.94+/-0.03 in NC, and 6.87+/-1.23 %/0.98+/-0.01 in PD with subdivided ROI. The test/retest variability/reliability of RT was 11.1+/-10.4%/0.59 in NC, 7.84+/-8.94%/0.95 in PD with whole striatal ROI, 11.9+/-1.22%/0.65+/-0.06 in NC, and 12.2+/-4.00%/0.95+/-0.03 in PD with subdivided ROI. CONCLUSION: R(V) is highly reproducible and reliable compared with RT in both NC and PD as an outcome measure.


Brain/diagnostic imaging , Brain/metabolism , Membrane Glycoproteins/metabolism , Membrane Transport Proteins/metabolism , Nerve Tissue Proteins/metabolism , Parkinson Disease/diagnostic imaging , Parkinson Disease/metabolism , Tropanes/pharmacokinetics , Adult , Aged , Dopamine Plasma Membrane Transport Proteins , Female , Humans , Image Interpretation, Computer-Assisted/methods , Male , Middle Aged , Radiopharmaceuticals/pharmacokinetics , Reference Values , Reproducibility of Results , Sensitivity and Specificity , Tissue Distribution , Tomography, Emission-Computed, Single-Photon/methods
14.
Exp Neurol ; 183(1): 109-15, 2003 Sep.
Article En | MEDLINE | ID: mdl-12957494

The gene defect in Huntington's disease (HD) causes a polyglutamine expansion in the N-terminal region of huntingtin (N-htt). In vitro studies suggest that mutant N-htt fragments can aggregate and cause cell death in HD. The physiological and pathological conditions that affect htt proteolysis in the brain are unclear. We examined htt expression by Western blot in the rat brain after transient ischemic injury, which causes striatal neurodegeneration similar to that seen in HD and activates proteases including calcium-dependent calpains. Focal brain ischemia reduced levels of full-length htt in the infarcted cortex and striatum and increased expression of a 55-kDa N-htt fragment that was also produced by treating control brain extracts with calpain. N-htt fragments between 65 and 80 kDa also rose after injury, but these fragments were not as long-lived as the 55-kDa N-htt fragment. The results suggest that after ischemic injury full-length htt is degraded in degenerating neurons and an N-htt fragment accumulates.


Calpain/metabolism , Ischemic Attack, Transient/metabolism , Nerve Tissue Proteins/metabolism , Nuclear Proteins/metabolism , Peptide Fragments/biosynthesis , Animals , Blotting, Western , Brain/metabolism , Brain/pathology , Cell Death , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Corpus Striatum/metabolism , Corpus Striatum/pathology , Disease Models, Animal , Disease Progression , Huntingtin Protein , Ischemic Attack, Transient/pathology , Male , Neurons/metabolism , Neurons/pathology , Peptide Fragments/analysis , Rats , Rats, Sprague-Dawley
15.
Mov Disord ; 17(2): 303-12, 2002 Mar.
Article En | MEDLINE | ID: mdl-11921116

It is often difficult to differentiate clinically between Parkinson's disease (PD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). The objective of this work was to investigate whether combined pre- and postsynaptic dopaminergic single photon emission computed tomography (SPECT) scanning can reliably demonstrate changes in the nigrostriatal dopaminergic system and help differentiate between normal controls, PD, MSA, and PSP patients. We performed SPECT evaluation of the dopamine transporter (DAT) and dopamine D2 receptors (D2). SPECT scans using [123I]beta-CIT (for DAT) and [123I]IBF (for D2) were performed in 18 patients with PD (12 dopa-naïve and 6 on levodopa and/or dopamine agonists), 7 with MSA of the striatonigral degeneration type, 6 with PSP, and 29 normal controls. Antiparkinsonian drugs were withheld for at least 12 hours before the scans. DAT and D2 binding potentials (Rv = V3/V2) were measured for caudate, anterior, and posterior putamen on the sides ipsilateral and contralateral to the worst motor symptoms. DAT binding in the posterior putamen was markedly reduced in all patients. However, D2 binding in posterior putamen was significantly increased in dopa-untreated PD, being greater than the normal range in 4 of 12 (33%), and it was significantly reduced in MSA, being below the normal range in 5 of 7 (71%). None of the patients with PD showed reduced D2 binding below the normal range in posterior putamen. The degree of DAT binding could not discriminate between the patient groups. The ratio of posterior putamen to caudate percentage D2 Rv compared with the controls showed an opposite pattern between PD or PSP and MSA; the caudate was greater in 16 of 18 with PD and 6 of 6 with PSP, whereas caudate was less in 5 of 7 with MSA. These findings suggest that DAT SPECT may be useful in differentiating parkinsonism from controls and D2 SPECT in further differentiating MSA from Parkinson's disease and possibly PSP.


Membrane Glycoproteins , Membrane Transport Proteins/physiology , Multiple System Atrophy/diagnostic imaging , Nerve Tissue Proteins , Parkinson Disease/diagnostic imaging , Receptors, Dopamine D2/physiology , Supranuclear Palsy, Progressive/diagnostic imaging , Tomography, Emission-Computed, Single-Photon , Aged , Brain/diagnostic imaging , Brain/physiopathology , Diagnosis, Differential , Dopamine Plasma Membrane Transport Proteins , Female , Humans , Iodine Radioisotopes , Male , Middle Aged , Multiple System Atrophy/physiopathology , Neurologic Examination , Parkinson Disease/physiopathology , Sensitivity and Specificity , Supranuclear Palsy, Progressive/physiopathology
16.
J Biol Chem ; 277(9): 7466-76, 2002 Mar 01.
Article En | MEDLINE | ID: mdl-11739372

Huntingtin is a protein of unknown function that contains a polyglutamine tract, which is expanded in patients with Huntington's disease (HD). We investigated the localization and a potential function for huntingtin in the nucleus. In human fibroblasts from normal and HD patients, huntingtin localized diffusely in the nucleus and in subnuclear compartments identified as speckles, promyelocytic leukemia protein bodies, and nucleoli. Huntingtin-positive nuclear bodies redistributed after treatment with sodium butyrate. By Western blot, purified nuclei had low levels of full-length huntingtin compared with the cytoplasm but contained high levels of N- and C-terminal huntingtin fragments, which tightly bound the nuclear matrix. Full-length huntingtin co-immunoprecipitated with the transcriptional corepressor C-terminal binding protein, and polyglutamine expansion in huntingtin reduced this interaction. Full-length wild-type and mutant huntingtin repressed transcription when targeted to DNA. Truncated N-terminal mutant huntingtin repressed transcription, whereas the corresponding wild-type fragment did not repress transcription. We speculate that wild-type huntingtin may function in the nucleus in the assembly of nuclear matrix-bound protein complexes involved with transcriptional repression and RNA processing. Proteolysis of mutant huntingtin may alter nuclear functions by disrupting protein complexes and inappropriately repressing transcription in HD.


Cell Nucleus/metabolism , DNA-Binding Proteins/metabolism , Nerve Tissue Proteins/biosynthesis , Nuclear Proteins/biosynthesis , Phosphoproteins/metabolism , Transcription, Genetic , Alcohol Oxidoreductases , Animals , Blotting, Western , Brain/metabolism , COS Cells , Cell Line , Epitopes , Fibroblasts/metabolism , Humans , Huntingtin Protein , Huntington Disease/metabolism , Immunohistochemistry , Mice , Microscopy, Confocal , Models, Genetic , Mutation , Peptides/metabolism , Precipitin Tests , Protein Binding , Protein Structure, Tertiary , RNA/metabolism , Sodium Oxybate/pharmacology , Transfection
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