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1.
J Pharm Bioallied Sci ; 16(Suppl 1): S133-S135, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38595509

RESUMO

Objective: This research assessed the efficiencies of aloe vera, 0.1% triamcinolone acetonide, and 5% amlexanox in the management of OLP. Materials and Methods: A total of 120 participants diagnosed with oral lichen planus (OLP) were equally divided into three groups and treated with: aloe vera, (Group A), 0.1% triamcinolone acetonide (Group B), and 5% amlexanox (Group C) topical medicaments. The patients were evaluated for pain, using the visual analogue scale (VAS). They were also evaluated for ulcerative lesion type and erosive area on days 1, 7, and 15 of the study. Results: There was a statistically considerable decrease in the VAS pain scale score, reduction in the erosive area on buccal mucosa, and healing of ulcer from day 1st to 15th day with all three tested drugs. Conclusion: All drugs used in this study; aloe vera, triamcinolone acetonide, and amlexanox were effective in treating OLP patients.

2.
Indian J Pathol Microbiol ; 64(2): 339-342, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33851630

RESUMO

BACKGROUND: Soft tissue keratocysts (SKC) are extremely rare and show similar microscopic morphology to keratocystic odontogenic tumor. The aim was to investigate immunohistochemical (IHC) features and origin of SKCs developing in buccal mucosa and lateral facial deep region. MATERIAL AND METHODS: Expression of CK19, CK10/13, Ki67, Cyclin D1 and Osteopontin (OPN) of 9 SKCS were investigated using IHC. Forty different types of cysts in jaw/soft tissue were used as control. Follow-up was performed. RESULTS: CK10/13 positivity occurred more frequently and intensely in SKC and intraosseous parakeratinized odontogenic keratocysts (COKC). However, OPN positivity was observed only in COKC. CONCLUSION: This is the largest case series of SKCs; along with first attempt to investigate the expression of OPN on SKC. Given the microscopic and immunohistochemical features, we prefer the view that SKC is odontogenic origin but represents the soft tissue counterpart of COKC, since their expressions of OPN were extremely different.


Assuntos
Mucosa Bucal/patologia , Cistos Odontogênicos/diagnóstico , Cistos Odontogênicos/patologia , Tumores Odontogênicos/patologia , Adulto , Idoso , Ciclina D1/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Osteopontina/metabolismo
3.
Leg Med (Tokyo) ; 42: 101645, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31891866

RESUMO

Having a reliable, inexpensive and simple method to estimate 18 years of age would be of help in the forensic field. This study aimed to test the accuracy of the third molar maturity index (I3M) in indicating the legal adult age of 18 years. This retrospective cross-sectional study analysed 450 digital panoramic images of Eastern Chinese children and young adults (226 females and 224 males) aged between 14 and 22 years. A cut-off value of I3M < 0.08 was tested in discriminating adults from minors for both sex. For females, the sensitivity of the test (Se) was 75.0%, with a 95% confidence interval (95%CI) of 67.5% to 82.5%. The specificity of the test (Sp) was 100%. The proportion accurately classified (Ac) individuals was 85.8% (95%CI, 81.3% to 90.4%). The Bayes post-test probability was 100% (93.6% to 100%). For males, Se, Sp and Ac were 91.9% (95%CI, 87.1% to 96.7%), 92.0%(95%CI, 86.7% to 97.3%) and 92% (95%CI, 88.4% to 95.5%), respectively. The Bayes post-test probabilities was 92% (95%CI, 88.4% to 95.5%). Males were ahead in the development of third molars comparing to females according to I3M. A stepwise logistic regression analysis showed that both I3M and sex contribute to the regression model to discriminate adults (≥18 years) from minors (<18 years), while a receiver operating curve (ROC) analysis indicated some better accuracy of I3M < 0.12 in females, without statistically significant difference when compared to I3M < 0.08. The results of this study show that the cut-off value of I3M < 0.08 may help to discriminate Eastern Chinese adults from minors. However, further study should evaluate the usefulness and possible variability of I3M cut-off value in a specific population before used for legal and forensic procedures.


Assuntos
Determinação da Idade pelos Dentes/métodos , Dente Serotino/crescimento & desenvolvimento , Adolescente , Adulto , Povo Asiático , Estudos Transversais , Feminino , Medicina Legal , Humanos , Masculino , Estudos Retrospectivos , Adulto Jovem
4.
Indian J Med Res ; 143(2): 205-12, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27121518

RESUMO

BACKGROUND & OBJECTIVES: Chronic obstructive pulmonary disease (COPD) is characterized by slowly progressive airflow limitaion, chronic lung inflammation and associated systemic manifestations. The objective of this preliminary study was to investigate the levels of high sensitivity C reactive protein (hs CRP) and tumour necrosis factor-α (TNF-α) as markers of systemic inflammation and assessment of systemic vascular reactivity that may play an important role in development of cardiovascular disease in COPD patients. METHODS: Systemic vascular reactivity was assessed non-invasively by measuring peripheral pulse waveform changes during reactive hyperemia (RH) in 16 COPD patients and 14 controls by photoplethysmography technique (PPG). Parameters measured were pulse wave amplitude (PWA), slope and pulse transit time (PTT). Tumour necrosis factor-α (TNF-α) and hs CRP were measured as markers of inflammation. RESULTS: PWA during the 1 st , 2 nd and 3 rd minutes post release of occlusion were significantly higher than the baseline means in controls, whereas in the patient group there was no significant change in the PWA during any of the observed time periods following release of occlusion, in comparison to the baseline means. Similar results were observed in slope values for patients and controls. Maximum percentage change in PWA during RH with reference to baseline was significantly lower in patients as compared to controls (26.78±20.19 vs 57.20±19.80%, p<0.001). Maximum percentage change in slope during RH with reference to baseline was significantly lower in patients as compared to controls (19.77±10.73 vs 39.25±13.49%, P<0.001). A vascular tone response as represented by PTT was also impaired in the 3 rd minute of RH as compared to baseline mean values in COPD patients only. INTERPRETATION & CONCLUSIONS: Our findings showed raised hs CRP levels and impaired systemic vascular reactivity in COPD patients. Whether these may increase the risk of cardiovascular disease in COPD patients need to be confirmed in future studies with large sample size and appropriate study design.


Assuntos
Proteína C-Reativa/metabolismo , Inflamação/sangue , Doença Pulmonar Obstrutiva Crônica/sangue , Fator de Necrose Tumoral alfa/sangue , Adulto , Idoso , Feminino , Frequência Cardíaca , Humanos , Inflamação/fisiopatologia , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Análise de Onda de Pulso , Resistência Vascular/fisiologia
5.
Indian J Physiol Pharmacol ; 60(2): 155-166, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-29809373

RESUMO

BACKGROUND: Post-occlusive reactive hyperemia (RH) is impaired in Chronic Obstructive Pulmonary Disease (COPD) and Obstructive Sleep Apnea (OSA). The aim of the present study was to examine systemic vascular response and endothelial function in patients of Overlap Syndrome (OS) of COPD and OSA and also to investigate whether OS has any additional effect on endothelial dysfunction when compared to dysfunction caused by COPD alone. METHODS: 31 COPD patients and 13 healthy controls participated in the study. Overnight Polysomnogra was done to classify the patients into COPD only group (Apnea-Hypopnea Index <5) (n=15) and OS group (AHI >5) (n=16). Peripheral pulse waveform changes during reactive hyperemia were assessed using digital Photoplethysmography (PPG) technique in which pulse wave amplitude (PWA), Maximum slope of upstroke and Pulse Transit Time (PTT) were measured. C - reactive protein was assessed as marker of inflammation by ELISA. RESULTS: Maximum percentage changes in PWA during RH were significantly lower in the both COPD group [20.34(12.02-34.07)] (p<0.001) and Overlap Syndrome group [10.96(6.21-21.49)] (p<0.0001) as compared to Controls [49.79(46.03-65.32)], whereas amplitude responses were not significantly different in the COPD and OS group (p>0.05). Maximum percentage change in slope of upstroke showed similar responses in the three groups. CRP levels (mg/) were raised in COPD [11.60(1.75-15.00] (p<0.001) and OS group [12.52(5.28- 15.70))](p<0.0001) as compared to controls [0.59(0.58-0.91)]. Maximum percentage change in amplitude negatively correlated with serum CRP levels in COPD group (r=-0.557, p=0.03) and in OS group (r=-O.552, p= 0.02). FEV1% predicted positively correlated with maximum percentage change in amplitude in OS group(r=0.579, p=0.018). No correlation of AHI was found with any of the vascular function parameter in Overlap group. CONCLUSION: The patients with Overlap Syndrome have systemic inflammation and impaired reactive hyperaemia response. However, no additive effect of OSA was observed on impaired RH in patients with co-existing COPD.


Assuntos
Endotélio Vascular/fisiopatologia , Hiperemia/etiologia , Inflamação/etiologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Apneia Obstrutiva do Sono/fisiopatologia , Doenças do Tecido Conjuntivo Indiferenciado/fisiopatologia , Adulto , Idoso , Proteína C-Reativa/análise , Estudos de Casos e Controles , Frequência Cardíaca/fisiologia , Humanos , Pessoa de Meia-Idade , Polissonografia , Doença Pulmonar Obstrutiva Crônica/complicações , Análise de Onda de Pulso , Apneia Obstrutiva do Sono/complicações , Oclusão Terapêutica , Doenças do Tecido Conjuntivo Indiferenciado/complicações
6.
J Forensic Dent Sci ; 7(1): 76-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25709326

RESUMO

Everyone is born with a unique genetic blueprint i.e. its own genome. Special locations called loci on different chromosomes display predictable inheritance patterns that could be used to determine biological relationships. These locations contain specific DNA sequences, called markers, which forensic scientists use as identifying marks for individuals. Saliva is a potentially useful source of genomic DNA for genetic studies. Paternity testing is based on the premise that we inherit half our DNA from our father and half from our mother. Therefore, persons who are biologically related must share similar DNA profile. Conversely, the absence of similarities in the DNA profiles of the child and the alleged father is used as proof that no biological relationship exists. In this paper, a female complained for being raped a year back by Mr. X and accused him of being father of her 3-months-old baby girl. DNA testing was done using saliva for the child and blood sample from the mother and the suspected father. The finding presented here allows the use of saliva as an alternative source of blood.

7.
J Forensic Dent Sci ; 6(2): 81-5, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-25125913

RESUMO

UNLABELLED: Saliva has long been known for its diagnostic value in several diseases. It also has a potential to be used in forensic science. OBJECTIVE: The objective of this study is to compare the quantity and quality of DNA samples extracted from saliva with those extracted from blood in order to assess the feasibility of extracting sufficient DNA from saliva for its possible use in forensic identification. MATERIALS AND METHODS: Blood and saliva samples were collected from 20 volunteers and DNA extraction was performed through Phenol Chloroform technique. The quantity and quality of isolated DNA was analyzed by spectrophotometery and the samples were then used to amplify short tandem repeat (STR) F13 using the polymerase chain reaction. RESULTS: Mean quantity of DNA obtained in saliva was 48.4 ± 8.2 µg/ml and in blood was 142.5 ± 45.9 µg/ml. Purity of DNA obtained as assessed by the ratio of optical density 260/280, was found to be optimal in 45% salivary samples while remaining showed minor contamination. Despite this positive F13 STR amplification was achieved in 75% of salivary DNA samples. CONCLUSION: Results of this study showed that saliva may prove to be a useful source of DNA for forensic purpose.

8.
Artigo em Inglês | MEDLINE | ID: mdl-25125975

RESUMO

Chronic obstructive pulmonary disease (COPD) is a major global health problem. It results from chronic inflammation and causes irreversible airway damage. Levels of different serum cytokines could be surrogate biomarkers for inflammation and lung function in COPD. We aimed to determine the serum levels of different biomarkers in COPD patients, the association between cytokine levels and various prognostic parameters, and the key pathways/networks involved in stable COPD. In this study, serum levels of 48 cytokines were examined by multiplex assays in 30 subjects (control, n=9; COPD, n=21). Relationships between serum biomarkers and forced expiratory volume in 1 second, peak oxygen uptake, body mass index, dyspnea score, and smoking were assessed. Enrichment pathways and network analyses were implemented, using a list of cytokines showing differential expression between healthy controls and patients with COPD by Cytoscape and GeneGo Metacore™ software (Thomson-Reuters Corporation, New York, NY, USA). Concentrations of cutaneous T-cell attracting chemokine, eotaxin, hepatocyte growth factor, interleukin 6 (IL-6), IL-16, and stem cell factor are significantly higher in COPD patients compared with in control patients. Notably, this study identifies stem cell factor as a biomarker for COPD. Multiple regression analysis predicts that cutaneous T-cell-attracting chemokine, eotaxin, IL-6, and stem cell factor are inversely associated with forced expiratory volume in 1 second and peak oxygen uptake change, whereas smoking is related to eotaxin and hepatocyte growth factor changes. Enrichment pathways and network analyses reveal the potential involvement of specific inflammatory and immune process pathways in COPD. Identified network interaction and regulation of different cytokines would pave the way for deeper insight into mechanisms of the disease process.


Assuntos
Citocinas/sangue , Mediadores da Inflamação/sangue , Análise Serial de Proteínas , Doença Pulmonar Obstrutiva Crônica/sangue , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Volume Expiratório Forçado , Humanos , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Mapas de Interação de Proteínas , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/imunologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Fatores de Risco , Transdução de Sinais , Fumar/efeitos adversos , Fumar/imunologia , Espirometria , Capacidade Vital
9.
J Forensic Dent Sci ; 5(2): 134-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24255563

RESUMO

UNLABELLED: Dentist can play a significant role in identifying the victims or perpetrators of crime as well as in disasters. Knowledge about the various aspects of forensic science as well as dental and related evidences can help a dental practitioner in assisting the civil agencies in such cases. AIM: To evaluate the awareness and knowledge of forensic odontology among dentists in a metropolitan and a tier 2 city. MATERIALS AND METHODS: Seven hundred and seventy four dentists were included in this survey. Questionnaire was designed to assess the knowledge, aptitude, and status of practice of forensic odontology. Data was analyzed by comparing overall awareness of forensic odontology among dentists in metro and tier 2 city as well as between the different groups. RESULTS: Apart from the source of knowledge, no significant differences were seen in respondents of metropolitan and tier 2 city. Significantly higher proportion of subjects in metro reported journals as source of knowledge (P < 0.001), whereas it was newspaper in tier 2 city (P = 0.001). On comparing the mean scores of knowledge (k), aptitude (a), and practice (p) among different study groups, it was found that all the three scores were highest for practitioner cum academician (PA) group (k - 2.37, a - 0.69, P - 0.17). Knowledge scores were minimum for pure practitioner (PP) group (1.98), and attitude and practice scores of pure academician (A) group were minimum (a - 0.53, P - 0.06). CONCLUSION: Respondents had low knowledge about the applications of forensic odontology in routine practice; hence, steps must be taken to educate the dental practitioners about its clinical applications.

10.
Dev Biol ; 376(2): 213-23, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23391688

RESUMO

Ci-MRF is the sole myogenic regulatory factor (MRF) of the ascidian Ciona intestinalis, an invertebrate chordate. In order to investigate its properties we developed a simple in vivo assay based on misexpressing Ci-MRF in the notochord of Ciona embryos. We used this assay to examine the roles of three structural motifs that are conserved among MRFs: an alanine-threonine (Ala-Thr) dipeptide of the basic domain that is known in vertebrates as the myogenic code, a cysteine/histidine-rich (C/H) domain found just N-terminal to the basic domain, and a carboxy-terminal amphipathic α-helix referred to as Helix III. We show that the Ala-Thr dipeptide is necessary for normal Ci-MRF function, and that while eliminating the C/H domain or Helix III individually has no demonstrable effect on Ci-MRF, simultaneous loss of both motifs significantly reduces its activity. Our studies also indicate that direct interaction between CiMRF and an essential E-box of Ciona Troponin I is required for the expression of this muscle-specific gene and that multiple classes of MRF-regulated genes exist in Ciona. These findings are consistent with substantial conservation of MRF-directed myogenesis in chordates and demonstrate for the first time that the Ala/Thr dipeptide of the basic domain of an invertebrate MRF behaves as a myogenic code.


Assuntos
Ciona intestinalis/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Regulação Miogênica/fisiologia , Alanina/genética , Animais , Cordados/genética , Modelos Biológicos , Desenvolvimento Muscular , Músculos/metabolismo , Mutação , Fatores de Regulação Miogênica/genética , Notocorda/metabolismo , Peptídeos/química , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Treonina/genética
11.
Nucleic Acids Res ; 39(7): 2638-48, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21109525

RESUMO

In conventionally-expressed eukaryotic genes, transcription start sites (TSSs) can be identified by mapping the mature mRNA 5'-terminal sequence onto the genome. However, this approach is not applicable to genes that undergo pre-mRNA 5'-leader trans-splicing (SL trans-splicing) because the original 5'-segment of the primary transcript is replaced by the spliced leader sequence during the trans-splicing reaction and is discarded. Thus TSS mapping for trans-spliced genes requires different approaches. We describe two such approaches and show that they generate precisely agreeing results for an SL trans-spliced gene encoding the muscle protein troponin I in the ascidian tunicate chordate Ciona intestinalis. One method is based on experimental deletion of trans-splice acceptor sites and the other is based on high-throughput mRNA 5'-RACE sequence analysis of natural RNA populations in order to detect minor transcripts containing the pre-mRNA's original 5'-end. Both methods identified a single major troponin I TSS located ∼460 nt upstream of the trans-splice acceptor site. Further experimental analysis identified a functionally important TATA element 31 nt upstream of the start site. The two methods employed have complementary strengths and are broadly applicable to mapping promoters/TSSs for trans-spliced genes in tunicates and in trans-splicing organisms from other phyla.


Assuntos
Mapeamento Cromossômico/métodos , Ciona intestinalis/genética , Regiões Promotoras Genéticas , Trans-Splicing , Sítio de Iniciação de Transcrição , Troponina I/genética , Regiões 5' não Traduzidas , Animais , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de RNA , TATA Box
12.
J Neurochem ; 115(4): 984-93, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20831599

RESUMO

Vesicular acetylcholine transporter (VAChT; TC 2.A.1.2.13) mediates storage of acetylcholine (ACh) by synaptic vesicles. A three-dimensional homology model of VAChT is available, but the binding sites for ACh and the allosteric inhibitor (-)-trans-2-(4-phenylpiperidino)cyclohexanol (vesamicol) are unknown. In previous work, mutations of invariant W331 in the lumenal beginning of transmembrane helix VIII (TM VIII) of rat VAChT led to as much as ninefold loss in equilibrium affinity for ACh and no loss in affinity for vesamicol. The current work investigates the effects of additional mutations in and around W331 and the nearby lumenal end of the substrate transport channel. Mutants of human VAChT were expressed in the PC12(A123.7) cell line and characterized using radiolabeled ligands and filtration assays for binding and transport. Properties of a new and a repeat mutation in W331 are consistent with the original observations. Of 16 additional mutations in 13 other residues (Y60 in the beginning of lumenal Loop I/II, F231 in the lumenal end of TM V, W315, M316, K317, in the lumenal end of TM VII, M320, A321, W325, A330 in lumenal Loop VII/VIII, A334 in the lumenal beginning of TM VIII, and C388, C391, F392 in the lumenal beginning of TM X), only A334F impairs binding. This mutation decreases ACh and vesamicol equilibrium binding affinities by 14- and 4-fold, respectively. The current results, combined with previous results, demonstrate existence of a spatial cluster of residues close to vesicular lumen that decreases affinity for ACh and/or vesamicol when the cluster is mutated. The cluster is composed of invariant W331, highly conserved A334, and invariant F335 in TM VIII and invariant C391 in TM X. Different models for the locations of the ACh and vesamicol binding sites relative to this cluster are discussed.


Assuntos
Acetilcolina/metabolismo , Piperidinas/metabolismo , Proteínas Vesiculares de Transporte de Acetilcolina/química , Proteínas Vesiculares de Transporte de Acetilcolina/metabolismo , Acetilcolina/química , Regulação Alostérica/genética , Substituição de Aminoácidos/genética , Animais , Sítios de Ligação/genética , Ligação Competitiva/genética , Sequência Conservada , Variação Genética , Humanos , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mutagênese Sítio-Dirigida , Células PC12 , Piperidinas/química , Estrutura Terciária de Proteína/genética , Transporte Proteico/genética , Ratos , Proteínas Vesiculares de Transporte de Acetilcolina/genética
13.
Methods Mol Biol ; 637: 181-219, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20419436

RESUMO

The method describes production and the selection of neurosecretory PC12A123.7 cells stably transfected with human vesicular acetylcholine transporter (hVAChT). Transfected cells provide postnuclear supernatant used to characterize equilibrium binding of the neurotransmitter acetylcholine (ACh), the pH dependence for transport of ACh, and the rate behavior for dissociation of the allosteric, high-affinity inhibitor vesamicol. Retention of radiolabeled ACh or vesamicol, mediated by hVAChT in synaptic-like microvesicles of postnuclear supernatant, is measured using filter assays. The procedure for regression analysis of data also is described.


Assuntos
Proteínas Vesiculares de Transporte de Acetilcolina/metabolismo , Acetilcolina/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Western Blotting , Concentração de Íons de Hidrogênio , Células PC12 , Piperidinas/metabolismo , Piperidinas/farmacologia , Ligação Proteica , Ratos , Proteínas Vesiculares de Transporte de Acetilcolina/antagonistas & inibidores
14.
Biochemistry ; 49(14): 3049-59, 2010 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-20225888

RESUMO

Invariant E309 is in contact with critical and invariant D398 in a three-dimensional homology model of vesicular acetylcholine transporter (VAChT, TC 2.A.1.2.13) [Vardy, E., et al. (2004) Protein Sci. 13, 1832-1840]. In the work reported here, E309 and D398 in human VAChT were mutated singly and together to test their functions, assign pK values to them, and determine whether the residues are close to each other in three-dimensional space. Mutants were stably expressed in the PC12(A123.7) cell line, and transport and binding properties were characterized at different pH values using radiolabeled ligands and filtration assays. Contrary to a prior conclusion, the results demonstrate that most D398 mutants do not bind the allosteric inhibitor vesamicol even weakly. Earlier work showed that most D398 mutants do not transport ACh. D398 therefore probably is the residue that must deprotonate with a pK of 6.5 for binding of vesamicol and with a pK of approximately 5.9 for transport of ACh. Because E309Q has no effect on VAChT functions at physiological pH, E309 has no apparent critical role. However, radical mutations in E309 cause decreases in ACh and vesamicol affinities and total loss of ACh transport. Unlike wild-type VAChT, which exhibits a peak of [(3)H]vesamicol binding centered at pH 7.4, mutants E309Q, E309D, E309A, and E309K all exhibit peaks of binding centered at pH >or=9. The combination of high pH and mutated E309 apparently produces a relaxed (in contrast to tense) conformation of VAChT that binds vesamicol exceptionally tightly. No compensatory interactions between E309 and D398 in double mutants were discovered. Proof of a close spatial relationship between E309 and D398 was not found. Nevertheless, the data are more consistent with the homology model than an alternative hydropathy model of VAChT that likely locates E309 far from D398 and the ACh binding site in three-dimensional space. Also, a probable network of interactions involving E309 and an unknown residue having a pK of 10 has been revealed.


Assuntos
Proteínas Vesiculares de Transporte de Acetilcolina/metabolismo , Acetilcolina/metabolismo , Animais , Transporte Biológico , Humanos , Concentração de Íons de Hidrogênio , Modelos Moleculares , Mutação , Células PC12 , Piperidinas/metabolismo , Conformação Proteica , Ensaio Radioligante , Ratos , Proteínas Vesiculares de Transporte de Acetilcolina/genética
15.
Biochemistry ; 48(38): 8965-75, 2009 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-19685929

RESUMO

Vesicular acetylcholine transporter (VAChT) is inhibited by (-)-vesamicol [(-)-trans-2-(4-phenylpiperidino)cyclohexanol], which binds tightly to an allosteric site. The tertiary alkylamine center in (-)-vesamicol is protonated and positively charged at acidic and neutral pH and unprotonated and uncharged at alkaline pH. Deprotonation of the amine has been taken to explain loss of (-)-vesamicol binding at alkaline pH. However, binding data deviate from a stereotypical bell shape, and more binding occurs than expected at alkaline pH. The current study characterizes the binding of (-)-vesamicol from pH 5 to pH 10 using filter assays, (-)-[3H]vesamicol (hereafter called [3H]vesamicol), and human VAChT expressed in PC12(A123.7) cells. At acidic pH, protons and [3H]vesamicol compete for binding to VAChT. Preexposure or long-term exposure of VAChT to high pH does not affect binding, thus eliminating potential denaturation of VAChT and failure of the filter assay. The dissociation constant for the complex between protonated [3H]vesamicol and VAChT decreases from 12 nM at neutral pH to 2.1 nM at pH 10. The simplest model of VAChT that explains the behavior requires a proton at site 1 to dissociate with pK1 = 6.5 +/- 0.1, a proton at site A to dissociate with pKA = 7.6 +/- 0.2, and a proton at site B to dissociate with pKB = 10.0 +/- 0.1. Deprotonation of the site 1 proton is obligatory for [3H]vesamicol binding. Deprotonation of site A decreases affinity (2.2 +/- 0.5)-fold, and deprotonation of site B increases affinity (18 +/- 4)-fold. Time-dependent dissociation of bound [3H]vesamicol is biphasic, but equilibrium saturation curves are not. The contrasting phasicity suggests that the pathway to and from the [3H]vesamicol binding site exists in open and at least partially closed states. The potential significance of the findings to development of PET and SPECT ligands based on (-)-vesamicol for human diagnostics also is discussed.


Assuntos
Piperidinas/metabolismo , Proteínas Vesiculares de Transporte de Acetilcolina/química , Proteínas Vesiculares de Transporte de Acetilcolina/metabolismo , Sítio Alostérico , Animais , Ligação Competitiva , Estabilidade Enzimática , Humanos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Cinética , Modelos Químicos , Células PC12 , Piperidinas/farmacologia , Prótons , Ratos , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Trítio , Proteínas Vesiculares de Transporte de Acetilcolina/antagonistas & inibidores , Proteínas Vesiculares de Transporte de Acetilcolina/genética
16.
J Neurosci ; 23(12): 5319-28, 2003 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-12832557

RESUMO

The locomotion of Caenorhabditis elegans consists of forward crawling punctuated by spontaneous reversals. To better understand the important variables that affect locomotion, we have described in detail the locomotory behavior of C. elegans and identified a set of parameters that are sufficient to describe the animal's trajectory. A model of locomotion based on these parameters indicates that reversal frequency plays a central role in locomotion. We found that several variables such as humidity, gravidity, and mechanostimulation influence reversal frequency. Specifically, both gentle and harsh touch can transiently suppress reversal frequency. Thus, reversal behavior is a model for the integration of information from numerous modalities reflecting diverse aspects of the state of an organism.


Assuntos
Comportamento Animal/fisiologia , Caenorhabditis elegans/fisiologia , Locomoção/fisiologia , Modelos Biológicos , Atividade Motora/fisiologia , Animais , Simulação por Computador , Meio Ambiente , Plasticidade Neuronal/fisiologia , Estimulação Física/métodos , Estimulação Química , Tato/fisiologia
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