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1.
Semin Arthritis Rheum ; 48(5): 821-827, 2019 04.
Article in English | MEDLINE | ID: mdl-30190154

ABSTRACT

OBJECTIVE: To investigate factors associated with delay in initiation of initial disease-modifying antirheumatic drug (DMARD) in patients newly diagnosed with rheumatoid arthritis (RA). METHODS: We performed a retrospective cohort descriptive study using administrative data from the US military's TRICARE program (2007-2012). We identified incident RA cases using billing codes and initial DMARD receipt using prescription fill date. We quantified the time between RA presentation and initial DMARD receipt, evaluated temporal changes in delay over the study period, and investigated predictors of treatment delay (> 90 days) using logistic regression. RESULTS: We identified 16,680 patients with incident RA that were prescribed DMARDs and mean age was 47.2 (SD 13.5) years. The mean time from initial RA presentation to first DMARD prescription receipt was 125.3days (SD 175.4). Over one-third (35.6%) of incident RA patients initiated DMARD > 90days after presentation. There was less treatment delay in later years of the study (mean days to DMARD of 144.7days in 2007; 109.7days in 2012). Patients prescribed opioids had mean time to DMARD of 212.8days (SD 207.4) compared to mean of 77.3days (SD 132.3) for those who did not use opioids (p < 0.0001). Patients prescribed opioids between RA presentation and initial DMARD receipt were more likely to have delay in initial DMARD (OR 4.07, 95% CI: 3.78-4.37). CONCLUSION: In this large US nationwide study, delays in initial DMARD receipt for incident RA were common but time to treatment improved in recent years. While further analysis using clinical data is warranted, these findings suggest that limiting opioid use in patients newly presenting with RA may decrease delay in initiating DMARDs.


Subject(s)
Antirheumatic Agents/therapeutic use , Arthritis, Rheumatoid/drug therapy , Practice Patterns, Physicians'/statistics & numerical data , Adult , Aged , Analgesics, Opioid/therapeutic use , Delayed Diagnosis , Female , Humans , Insurance, Health/statistics & numerical data , Kaplan-Meier Estimate , Logistic Models , Male , Middle Aged , Military Medicine/statistics & numerical data , Retrospective Studies , Time-to-Treatment , United States/epidemiology
2.
Sci Rep ; 7(1): 17993, 2017 12 21.
Article in English | MEDLINE | ID: mdl-29269946

ABSTRACT

CARM1 is an arginine methyltransferase with diverse histone and non-histone substrates implicated in the regulation of cellular processes including transcriptional co-activation and RNA processing. CARM1 overexpression has been reported in multiple cancer types and has been shown to modulate oncogenic pathways in in vitro studies. Detailed understanding of the mechanism of action of CARM1 in oncogenesis has been limited by a lack of selective tool compounds, particularly for in vivo studies. We describe the identification and characterization of, to our knowledge, the first potent and selective inhibitor of CARM1 that exhibits anti-proliferative effects both in vitro and in vivo and, to our knowledge, the first demonstration of a role for CARM1 in multiple myeloma (MM). EZM2302 (GSK3359088) is an inhibitor of CARM1 enzymatic activity in biochemical assays (IC50 = 6 nM) with broad selectivity against other histone methyltransferases. Treatment of MM cell lines with EZM2302 leads to inhibition of PABP1 and SMB methylation and cell stasis with IC50 values in the nanomolar range. Oral dosing of EZM2302 demonstrates dose-dependent in vivo CARM1 inhibition and anti-tumor activity in an MM xenograft model. EZM2302 is a validated chemical probe suitable for further understanding the biological role CARM1 plays in cancer and other diseases.


Subject(s)
Antineoplastic Agents/therapeutic use , CARD Signaling Adaptor Proteins/antagonists & inhibitors , Enzyme Inhibitors/therapeutic use , Guanylate Cyclase/antagonists & inhibitors , Isoxazoles/therapeutic use , Multiple Myeloma/drug therapy , Pyrimidines/therapeutic use , Spiro Compounds/therapeutic use , Animals , Antineoplastic Agents/pharmacokinetics , Cell Line, Tumor , Dose-Response Relationship, Drug , Enzyme Inhibitors/pharmacokinetics , Humans , In Vitro Techniques , Isoxazoles/pharmacokinetics , Male , Mice , Neoplasm Transplantation , Pyrimidines/pharmacokinetics , Rats, Sprague-Dawley , Spiro Compounds/pharmacokinetics
3.
Mol Cancer Ther ; 16(11): 2586-2597, 2017 11.
Article in English | MEDLINE | ID: mdl-28835384

ABSTRACT

The EZH2 small-molecule inhibitor tazemetostat (EPZ-6438) is currently being evaluated in phase II clinical trials for the treatment of non-Hodgkin lymphoma (NHL). We have previously shown that EZH2 inhibitors display an antiproliferative effect in multiple preclinical models of NHL, and that models bearing gain-of-function mutations in EZH2 were consistently more sensitive to EZH2 inhibition than lymphomas with wild-type (WT) EZH2 Here, we demonstrate that cell lines bearing EZH2 mutations show a cytotoxic response, while cell lines with WT-EZH2 show a cytostatic response and only tumor growth inhibition without regression in a xenograft model. Previous work has demonstrated that cotreatment with tazemetostat and glucocorticoid receptor agonists lead to a synergistic antiproliferative effect in both mutant and wild-type backgrounds, which may provide clues to the mechanism of action of EZH2 inhibition in WT-EZH2 models. Multiple agents that inhibit the B-cell receptor pathway (e.g., ibrutinib) were found to have synergistic benefit when combined with tazemetostat in both mutant and WT-EZH2 backgrounds of diffuse large B-cell lymphomas (DLBCL). The relationship between B-cell activation and EZH2 inhibition is consistent with the proposed role of EZH2 in B-cell maturation. To further support this, we observe that cell lines treated with tazemetostat show an increase in the B-cell maturation regulator, PRDM1/BLIMP1, and gene signatures corresponding to more advanced stages of maturation. These findings suggest that EZH2 inhibition in both mutant and wild-type backgrounds leads to increased B-cell maturation and a greater dependence on B-cell activation signaling. Mol Cancer Ther; 16(11); 2586-97. ©2017 AACR.


Subject(s)
Benzamides/administration & dosage , Enhancer of Zeste Homolog 2 Protein/genetics , Lymphoma, Large B-Cell, Diffuse/drug therapy , Pyrazoles/administration & dosage , Pyridones/administration & dosage , Pyrimidines/administration & dosage , Adenine/analogs & derivatives , Animals , B-Lymphocytes/drug effects , Biphenyl Compounds , Cell Proliferation/drug effects , DNA Methylation/drug effects , Drug Synergism , Enhancer of Zeste Homolog 2 Protein/antagonists & inhibitors , Gene Expression Regulation, Neoplastic/drug effects , Humans , Lymphoma, Large B-Cell, Diffuse/genetics , Lymphoma, Large B-Cell, Diffuse/pathology , Mice , Morpholines , Mutation , Piperidines , Signal Transduction/drug effects , Xenograft Model Antitumor Assays
4.
Mol Cancer Ther ; 16(5): 850-860, 2017 05.
Article in English | MEDLINE | ID: mdl-28292935

ABSTRACT

The SWI/SNF complex is a major regulator of gene expression and is increasingly thought to play an important role in human cancer, as evidenced by the high frequency of subunit mutations across virtually all cancer types. We previously reported that in preclinical models, malignant rhabdoid tumors, which are deficient in the SWI/SNF core component INI1 (SMARCB1), are selectively killed by inhibitors of the H3K27 histone methyltransferase EZH2. Given the demonstrated antagonistic activities of the SWI/SNF complex and the EZH2-containing PRC2 complex, we investigated whether additional cancers with SWI/SNF mutations are sensitive to selective EZH2 inhibition. It has been recently reported that ovarian cancers with dual loss of the redundant SWI/SNF components SMARCA4 and SMARCA2 are characteristic of a rare rhabdoid-like subtype known as small-cell carcinoma of the ovary hypercalcemic type (SCCOHT). Here, we provide evidence that a subset of commonly used ovarian carcinoma cell lines were misdiagnosed and instead were derived from a SCCOHT tumor. We also demonstrate that tazemetostat, a potent and selective EZH2 inhibitor currently in phase II clinical trials, induces potent antiproliferative and antitumor effects in SCCOHT cell lines and xenografts deficient in both SMARCA2 and SMARCA4. These results exemplify an additional class of rhabdoid-like tumors that are dependent on EZH2 activity for survival. Mol Cancer Ther; 16(5); 850-60. ©2017 AACR.


Subject(s)
Carcinoma, Small Cell/drug therapy , DNA Helicases/genetics , Enhancer of Zeste Homolog 2 Protein/genetics , Nuclear Proteins/genetics , Ovarian Neoplasms/drug therapy , Rhabdoid Tumor/drug therapy , Transcription Factors/genetics , Animals , Carcinoma, Small Cell/diagnosis , Carcinoma, Small Cell/genetics , Carcinoma, Small Cell/pathology , Cell Line, Tumor , Chromosomal Proteins, Non-Histone/genetics , Diagnosis, Differential , Enhancer of Zeste Homolog 2 Protein/antagonists & inhibitors , Female , Gene Expression Regulation, Neoplastic/drug effects , Histone-Lysine N-Methyltransferase/genetics , Humans , Hypercalcemia/diagnosis , Hypercalcemia/drug therapy , Hypercalcemia/genetics , Hypercalcemia/pathology , Mice , Mutation , Ovarian Neoplasms/diagnosis , Ovarian Neoplasms/genetics , Ovarian Neoplasms/pathology , Rhabdoid Tumor/diagnosis , Rhabdoid Tumor/genetics , Rhabdoid Tumor/pathology , Xenograft Model Antitumor Assays
5.
ACS Chem Biol ; 11(3): 763-71, 2016 Mar 18.
Article in English | MEDLINE | ID: mdl-26551522

ABSTRACT

Coactivator-associated arginine methyltransferase 1 (CARM1) is a protein arginine N-methyltransferase (PRMT) enzyme that has been implicated in a variety of cancers. CARM1 is known to methylate histone H3 and nonhistone substrates. To date, several crystal structures of CARM1 have been solved, including structures with small molecule inhibitors, but no ternary structures with nucleoside and peptide substrates have been reported. Here, the crystal structures of human CARM1 with the S-adenosylmethione (SAM) mimic sinefungin and three different peptide sequences from histone H3 and PABP1 are presented, with both nonmethylated and singly methylated arginine residues exemplified. This is the first example of multiple substrate sequences solved in a single PRMT enzyme and demonstrates how the CARM1 binding site is capable of accommodating a variety of peptide sequences while maintaining a core binding mode for the unmethylated and monomethylated substrates. Comparison of these with other PRMT enzyme-peptide structures shows hydrogen bonding patterns that may be thematic of these binding sites.


Subject(s)
Protein-Arginine N-Methyltransferases/metabolism , Binding Sites , Cell Line , Crystallography, X-Ray , Gene Expression Regulation, Enzymologic , Humans , Models, Molecular , Protein Conformation , Protein-Arginine N-Methyltransferases/chemistry , Protein-Arginine N-Methyltransferases/genetics , Substrate Specificity
6.
ACS Med Chem Lett ; 6(6): 655-9, 2015 Jun 11.
Article in English | MEDLINE | ID: mdl-26101569

ABSTRACT

A novel aryl pyrazole series of arginine methyltransferase inhibitors has been identified. Synthesis of analogues within this series yielded the first potent, selective, small molecule PRMT6 inhibitor tool compound, EPZ020411. PRMT6 overexpression has been reported in several cancer types suggesting that inhibition of PRMT6 activity may have therapeutic utility. Identification of EPZ020411 provides the field with the first small molecule tool compound for target validation studies. EPZ020411 shows good bioavailability following subcutaneous dosing in rats making it a suitable tool for in vivo studies.

7.
J Med Chem ; 55(14): 6523-40, 2012 Jul 26.
Article in English | MEDLINE | ID: mdl-22734674

ABSTRACT

A class of 2-acyliminobenzimidazoles has been developed as potent and selective inhibitors of anaplastic lymphoma kinase (ALK). Structure based design facilitated the rapid development of structure-activity relationships (SAR) and the optimization of kinase selectivity. Introduction of an optimally placed polar substituent was key to solving issues of metabolic stability and led to the development of potent, selective, orally bioavailable ALK inhibitors. Compound 49 achieved substantial tumor regression in an NPM-ALK driven murine tumor xenograft model when dosed qd. Compounds 36 and 49 show favorable potency and PK characteristics in preclinical species indicative of suitability for further development.


Subject(s)
Antineoplastic Agents/pharmacology , Antineoplastic Agents/pharmacokinetics , Drug Discovery , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/pharmacokinetics , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Administration, Oral , Anaplastic Lymphoma Kinase , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Biological Availability , Cell Line, Tumor , Drug Stability , Humans , Imidazoles/chemistry , Imidazoles/metabolism , Imidazoles/pharmacokinetics , Imidazoles/pharmacology , Inhibitory Concentration 50 , Microsomes, Liver/metabolism , Models, Molecular , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/metabolism , Protein Structure, Tertiary , Rats , Receptor Protein-Tyrosine Kinases/chemistry , Receptor Protein-Tyrosine Kinases/metabolism , Substrate Specificity
8.
Brain Inj ; 26(6): 814-24, 2012.
Article in English | MEDLINE | ID: mdl-22583172

ABSTRACT

OBJECTIVE: To investigate whether White, African American and Hispanic individuals with a traumatic brain injury (TBI) express differences in neurobehavioural symptoms at 1 year post-injury after adjusting for demographic and injury characteristics. DESIGN: Retrospective study. PARTICIPANTS: One thousand, three hundred and thirty-nine individuals from the TBI Model Systems National Database with primarily moderate-to-severe TBI (978 White, 288 African American and 73 Hispanic) hospitalized between 1996 and 2001. MAIN OUTCOME MEASURES: Neurobehavioural Functioning Inventory (NFI) at 1 year post-injury. RESULTS: There were significant differences in NFI scores among the races/ethnicities for the depression, somatic, memory/attention, communication and motor subscales, after adjusting for demographic and injury characteristics; there were not significant differences in the aggression sub-scale. Hispanics had higher levels of symptom reporting than African Americans and Whites, while differences between African Americans and Whites were not significant. CONCLUSIONS: Hispanics scored significantly higher than Whites and African Americans on the sub-scales of the NFI, indicating more problems in these areas. Future research should focus on identifying factors that may contribute to the difference between the groups and treatment interventions should be implemented accordingly.


Subject(s)
Black or African American , Brain Injuries/ethnology , Depression/ethnology , Hispanic or Latino , Memory Disorders/ethnology , White People , Adult , Black or African American/psychology , Black or African American/statistics & numerical data , Aggression , Analysis of Variance , Attention , Brain Injuries/complications , Brain Injuries/physiopathology , Depression/etiology , Female , Follow-Up Studies , Hispanic or Latino/psychology , Hispanic or Latino/statistics & numerical data , Humans , Male , Memory Disorders/etiology , Retrospective Studies , Time Factors , White People/psychology , White People/statistics & numerical data
9.
Brain Inj ; 26(6): 825-33, 2012.
Article in English | MEDLINE | ID: mdl-22583173

ABSTRACT

OBJECTIVE: To assess health-related quality of life (HRQoL) of individuals with traumatic brain injury (TBI) in Barranquilla, Colombia. PARTICIPANTS/METHODS: Thirty-one individuals with TBI and 61 healthy controls completed the SF-36, a self-report HRQoL measure composed of eight component areas: physical health problems, pain, role limitations due to physical problems or due to emotional problems, emotional well-being, social functioning, energy/fatigue and general health perceptions. RESULTS: The samples were statistically similar with respect to age, gender and education and statistically different with respect to depression, SES, social support and cognition. Compared to healthy controls, individuals with TBI had significantly lower means on all SF-36 sub-scales. However, after adjusting for depression, SES, social support and cognitive performance, significant differences remained on three of the SF-36 sub-scales. Specifically, individuals with TBI had lower adjusted means on Role-Physical (p-value < 0.005), Role-Emotional (p-value < 0.005) and Bodily Pain (p-value < 0.05). CONCLUSION: Even after controlling for depression, SES, social support and cognitive performance, individuals with TBI living in Barranquilla Colombia report having poorer quality of life across various domains, including Role-Physical, Role-Emotional and Bodily Pain. These findings suggest the need for rehabilitation health professionals to develop and implement culturally-appropriate interventions to improve quality of life in Colombian individuals with TBI.


Subject(s)
Brain Injuries/psychology , Depression/etiology , Employment/statistics & numerical data , Fatigue/etiology , Quality of Life , Activities of Daily Living , Adaptation, Psychological , Adult , Brain Injuries/complications , Brain Injuries/epidemiology , Brain Injuries/rehabilitation , Colombia/epidemiology , Depression/epidemiology , Depression/psychology , Educational Status , Fatigue/epidemiology , Fatigue/psychology , Female , Humans , Male , Recovery of Function , Social Support , Surveys and Questionnaires
10.
J Cardiovasc Comput Tomogr ; 5(4): 231-9, 2011.
Article in English | MEDLINE | ID: mdl-21723514

ABSTRACT

BACKGROUND: The relationship between chest lateral width, tube current, image noise, and radiation exposure on 320-detector row CT has not been reported. OBJECTIVE: We investigated the relationships between chest lateral width, estimated radiation exposure (DLPe), and image noise in 300 patients undergoing clinical coronary calcium scanning. METHODS: Patients undergoing coronary calcium scanning with 320-detector row CT (prospective, volumetric mode, 120 kV of tube voltage, 100-550 mA of tube current, 0.5-mm detector width) were grouped by chest lateral width (small, medium, and large) from anteroposterior topograms and 100 consecutive patients were selected from each group (n = 300). Tube current, DLPe, and noise were compared among groups with Kruskal-Wallis or one-way ANOVA. Phantom experiments were performed to evaluate the accuracy of calcium quantification as a function of size and tube current. RESULTS: Median tube current in small, medium, and large patients was 130, 200, and 250 mA, respectively (P < 0.0001). Despite the use of higher tube current settings, noise levels also increased with size (20.2 ± 4.5 HU, 22.0 ± 3.9 HU, and 25.1 ± 4.9 HU, respectively; global P < 0.001). DLPe was significantly higher with increasing size (54, 83, and 104 mGy · cm, respectively; P < 0.0001). Phantom experiments showed that 50-100 mA, 150-200 mA, and approximately 300 mA in small, medium, and large phantoms were associated with stable estimate of calcium. CONCLUSIONS: Increasing chest lateral width is associated with increasing radiation exposure and image noise. The use of 50-100 mA in small and 150-200 mA in medium patients is associated with acceptable noise and stable estimate of coronary artery calcium. In large patients, precise identification of individual calcified lesions remains difficult despite increasing tube current and radiation exposure.


Subject(s)
Anthropometry , Calcinosis/diagnostic imaging , Coronary Angiography/instrumentation , Coronary Artery Disease/diagnostic imaging , Radiation Dosage , Thorax/anatomy & histology , Tomography, X-Ray Computed/instrumentation , Aged , Algorithms , Analysis of Variance , Artifacts , Chi-Square Distribution , Equipment Design , Female , Georgia , Humans , Male , Middle Aged , Phantoms, Imaging , Predictive Value of Tests , Radiographic Image Interpretation, Computer-Assisted , Retrospective Studies , Severity of Illness Index
11.
J Biomol Screen ; 16(2): 164-73, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21297104

ABSTRACT

Anaplastic lymphoma kinase (ALK) when expressed as a fusion protein with nucleophosmin (NPM) has been implicated as a driving oncogene in a subset of lymphomas. Recent reports of ALK expression in a number of other cancers have raised the possibility that an ALK inhibitor may benefit patients with these diseases as well. In a campaign to identify and develop a selective ALK inhibitor, 2 assays were devised to measure the phosphorylation of tyrosine residue 1604 of ALK (pY(1604) ALK). Amplified Luminescent Proximity Homogeneous Assay (AlphaScreen(®)) and phosflow platforms were used to detect modulation of pY(1604) ALK to determine the relative potency of a set of small-molecule inhibitors. Prior to making use of these assays in diverse settings, the authors attempted to ensure their equivalence with a direct comparison of their performance. The pY(1604) ALK assays correlated well both with each other and with assays of ALK enzyme activity or ALK-dependent cell proliferation. The AlphaScreen(®) assay was amenable to automation and enabled rapid, high-throughput compound assessment in an NPM-ALK-driven cell line, whereas the phosflow assay enabled the authors to characterize the activity of compounds with respect to their impact on targeted enzymes and pathways. Results show that both AlphaScreen(®) and phosflow ALK assays exhibited diverse characteristics that made them desirable for different applications but were determined to be equally sensitive and robust in the detection of inhibition of pY(1604) ALK.


Subject(s)
Biological Assay , Phosphoproteins/metabolism , Protein-Tyrosine Kinases/antagonists & inhibitors , Anaplastic Lymphoma Kinase , Cell Line , Cell Proliferation/drug effects , Crizotinib , Enzyme Inhibitors/pharmacology , Humans , Piperidines/pharmacology , Protein-Tyrosine Kinases/metabolism , Pyrazoles , Pyridines/pharmacology , Receptor Protein-Tyrosine Kinases
12.
Am J Alzheimers Dis Other Demen ; 25(7): 556-61, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20826708

ABSTRACT

The purpose of this study was to compare the health-related quality of life (HRQoL) of 99 caregivers of individuals with dementia and 95 healthy individuals from the general population in Colombia. The 36-item short-form (SF-36), a self-report measure composed of 8 component areas (physical function, role-physical, bodily pain, general health, energy/vitality, social function, role-emotional, and mental health), was used to measure HRQoL. Results indicated that the healthy control group had a higher level of education, socioeconomic status (SES), and number of male participants. After adjusting for education, SES, and gender, the caregivers of individuals with dementia scored significantly lower on all of the SF-36 subscales than the healthy controls. These findings suggest the need for rehabilitation health professionals to develop and implement culturally appropriate interventions to improve the HRQoL of caregivers of individuals with dementia in Colombia.


Subject(s)
Caregivers/psychology , Dementia/psychology , Health Surveys , Quality of Life , Stress, Psychological/psychology , Aged , Colombia , Dementia/rehabilitation , Educational Status , Employment , Family Health , Female , Humans , Male , Middle Aged , Physical Fitness , Social Support , Socioeconomic Factors
13.
NeuroRehabilitation ; 27(1): 83-93, 2010.
Article in English | MEDLINE | ID: mdl-20634603

ABSTRACT

OBJECTIVE: 1) To determine the most frequent needs in a group of family caregivers of individuals with spinal cord injury in Neiva Colombia; 2) to describe caregivers' psychosocial functioning; and 3) to examine the relationship between caregiver needs and caregiver psychosocial functioning. DESIGN: Cross-sectional. PARTICIPANTS/METHODS: 37 caregivers completed a caregiver needs questionnaire composed of 27 questions (1-5 scale) and 9 sub-scales (emotional, information, economic, community, and household support, respite, physical health, sleep, and psychological health). The Patient Health Questionnaire (PHQ-9) was used to measure caregiver depression, the Zarit Burden Interview (ZBI) measured stress, the Interpersonal Support Evaluation List Short Version (ISEL-12) measured social support, and the Satisfaction With Life Scale (SWLS) was used to assess satisfaction with life. RESULTS: Information, economic, emotional, community support, and respite needs were most frequently reported among this group of Colombian caregivers. Forty-three percent of the family caregivers reported some level of depression, 68% reported being overwhelmed by their caretaking responsibilities, and 43% reported dissatisfaction with their lives. Information, emotional, economic, physical, sleep, and psychological needs were positively correlated with depression and burden. Those with more household, physical, sleep, economic, and psychological needs had less satisfaction with life and social support. Caregivers with more community and respite needs had less social support, while those with more emotional needs had less satisfaction with life. Caregivers with more respite needs had more burden and those with more household needs had more depression. CONCLUSION: Approximately half of the sample reports some level of burden, depression, or being dissatisfied with life. Psychosocial functioning was related to various family needs. Further longitudinal research is needed to determine whether caregivers with more needs report worse psychosocial functioning or if those with worse psychosocial functioning report more needs.


Subject(s)
Adaptation, Psychological , Caregivers/psychology , Family , Interpersonal Relations , Social Support , Spinal Cord Injuries/rehabilitation , Adult , Colombia , Cost of Illness , Cross-Sectional Studies , Depression/diagnosis , Depression/etiology , Female , Humans , Male , Middle Aged , Personal Satisfaction , Stress, Psychological/diagnosis , Stress, Psychological/etiology , Surveys and Questionnaires
14.
Schizophr Res ; 65(1): 47-55, 2003 Dec 01.
Article in English | MEDLINE | ID: mdl-14623374

ABSTRACT

Low levels of dopaminergic activity in prefrontal cortex are thought to contribute to negative symptoms of schizophrenia. Negative symptoms are associated with the prefrontocortical area of the brain. Schizophrenic patients have a high rate of smoking, which by subjective as well as objective measures produces a cognitive benefit. We have previously shown that agonists at nicotinic receptors containing alpha4 and beta2 subunits can enhance amphetamine-stimulated [3H]dopamine ([3H]DA) release via the dopamine transporter (DAT) from slices of rat prefrontal cortex. This effect is selective for prefrontal cortex; the enhancement does not occur in striatum or nucleus accumbens. The enhancement is dependent upon activation of protein kinase C (PKC). In the current study, we show that the enhancement of amphetamine-stimulated [3H]DA release is maintained after 10 days of chronic nicotine treatment, delivered subcutaneously twice daily. There are no significant changes in the ability of prefrontocortical brain slices to take up [3H]DA in tissue prepared from nicotine-treated vs. saline-treated rats. Nicotinic receptors mediating enhancement of amphetamine-stimulated [3H]DA release are at least partially localized to nerve terminals, as an enhancement in release is also observed in synaptosomal preparations. Finally, the sensitivity of the nicotine enhancement in release to the PKC inhibitor chelerythrine is also seen in synaptosomal preparations, suggesting that the signaling mechanism activated through alpha4beta2 receptors is intact.


Subject(s)
Membrane Glycoproteins , Membrane Transport Proteins/metabolism , Nerve Tissue Proteins , Prefrontal Cortex/drug effects , Tobacco Use Disorder/physiopathology , Alkaloids , Amphetamine/pharmacology , Animals , Benzophenanthridines , Culture Techniques , Dopamine/metabolism , Dopamine Plasma Membrane Transport Proteins , Injections, Subcutaneous , Male , Nicotine/pharmacology , Phenanthridines/pharmacology , Prefrontal Cortex/physiopathology , Protein Kinase C/antagonists & inhibitors , Protein Kinase C/physiology , Rats , Rats, Sprague-Dawley , Receptors, Nicotinic/drug effects , Receptors, Nicotinic/physiology , Signal Transduction/drug effects , Signal Transduction/physiology , Stimulation, Chemical , Synaptosomes/drug effects , Synaptosomes/physiology
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