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1.
J Am Chem Soc ; 144(7): 2933-2942, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35157427

RESUMO

Light-activated photosystem II (PSII) carries out the critical step of splitting water in photosynthesis. However, PSII is susceptible to light-induced damage. Here, results are presented from a novel microbial electro-photosynthetic system (MEPS) that uses redox mediators in conjunction with an electrode to drive electron transport in live Synechocystis (ΔpsbB) cells lacking PSII. MEPS-generated, light-dependent current increased with light intensity up to 2050 µmol photons m-2 s-1, which yielded a delivery rate of 113 µmol electrons h-1 mg-chl-1 and an average current density of 150 A m-2 s-1 mg-chl-1. P700+ re-reduction kinetics demonstrated that initial rates exceeded wildtype PSII-driven electron delivery. The electron delivery occurs ahead of the cytochrome b6f complex to enable both NADPH and ATP production. This work demonstrates an electrochemical system that can drive photosynthetic electron transport, provides a platform for photosynthetic foundational studies, and has the potential for improving photosynthetic performance at high light intensities.


Assuntos
Proteínas de Bactérias/metabolismo , Hidroquinonas/metabolismo , Fotossíntese/fisiologia , Complexo de Proteína do Fotossistema I/metabolismo , Proteínas de Bactérias/genética , Complexo Citocromos b6f/metabolismo , Eletroquímica/instrumentação , Eletroquímica/métodos , Elétrons , Hidroquinonas/química , Fotossíntese/genética , Complexo de Proteína do Fotossistema II/genética , Synechocystis/metabolismo
2.
Int J Mol Sci ; 21(4)2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32074957

RESUMO

Doxorubicin (DOX) is an effective chemotherapeutic agent used to treat a wide variety of malignancies. In addition to its multi-organ toxicity, DOX treatment has been shown to induce systemic inflammation in patients and experimental animals. Inflammation alters the expression of hepatic cytochrome P450 (CYP) enzymes, which play important roles in drug metabolism and DOX-induced toxicity. Significant sex differences have been reported in DOX-induced toxicity; however, sex differences in DOX-induced systemic inflammation and the potential effects on hepatic CYP expression have not been determined. In the current work, male and female C57Bl/6 mice were administered DOX (20 mg/kg by intraperitoneal injection), and groups of mice were sacrificed 24 and 72 h after DOX administration. DOX elicited a systemic inflammatory response in both male and female mice, but the inflammatory response was stronger in male mice. DOX altered the expression of hepatic CYP isoforms in a sex-dependent manner. Most notably, inhibition of Cyp2c29 and Cyp2e1 was stronger in male than in female mice, which paralleled the sex differences in systemic inflammation. Therefore, sex differences in DOX-induced systemic inflammation may lead to sexually dimorphic drug interactions, in addition to contributing to the previously reported sexual dimorphism in specific DOX-induced organ toxicity.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Doxorrubicina/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Fígado/enzimologia , Animais , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/genética , Feminino , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Injeções Intraperitoneais , Interleucina-6/sangue , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Caracteres Sexuais , Fator de Necrose Tumoral alfa/sangue
3.
Horm Behav ; 69: 39-49, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25528549

RESUMO

In rough-skinned newts, Taricha granulosa, exposure to an acute stressor results in the rapid release of corticosterone (CORT), which suppresses the ability of vasotocin (VT) to enhance clasping behavior. CORT also suppresses VT-induced spontaneous activity and sensory responsiveness of clasp-controlling neurons in the rostromedial reticular formation (Rf). The cellular mechanisms underlying this interaction remain unclear. We hypothesized that CORT blocks VT-enhanced clasping by interfering with V1a receptor availability and/or VT-induced endocytosis. We administered a physiologically active fluorescent VT conjugated to Oregon Green (VT-OG) to the fourth ventricle 9 min after an intraperitoneal injection of CORT (0, 10, 40 µg/0.1mL amphibian Ringers). The brains were collected 30 min post-VT-OG, fixed, and imaged with confocal microscopy. CORT diminished the number of endocytosed vesicles, percent area containing VT-OG, sum intensity of VT-OG, and the amount of VT-V1a within each vesicle; indicating that CORT was interfering with V1a receptor availability and VT-V1a receptor-mediated endocytosis. CORT actions were brain location-specific and season-dependent in a manner that is consistent with the natural and context-dependent expression of clasping behavior. Furthermore, the sensitivity of the Rf to CORT was much higher in animals during the breeding season, arguing for ethologically appropriate seasonal variation in CORT's ability to prevent VT-induced endocytosis. Our data are consistent with the time course and interaction effects of CORT and VT on clasping behavior and neurophysiology. CORT interference with VT-induced endocytosis may be a common mechanism employed by hormones across taxa for mediating rapid context- and season-specific behavioral responses.


Assuntos
Corticosterona/farmacologia , Receptores de Vasopressinas/metabolismo , Salamandridae , Comportamento Sexual Animal/efeitos dos fármacos , Vasotocina/fisiologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Regulação para Baixo/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Masculino , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Formação Reticular , Salamandridae/fisiologia , Comportamento Sexual Animal/fisiologia , Transdução de Sinais/efeitos dos fármacos , Vasotocina/metabolismo
4.
Bioorg Med Chem Lett ; 24(17): 4341-7, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25065493

RESUMO

The optimisation of two series of 4-hydroxybenzothiazolone derived ß2-adrenoceptor agonists, bearing α-substituted cyclopentyl and ß-phenethyl amino-substituents, as inhaled long-acting bronchodilators is described. Analogues were selected for synthesis using a lipophilicity based hypothesis to achieve the targeted rapid onset of action in combination with a long duration of action. The profiling of the two series led to identification of the α-substituted cyclopentyl analogue 2 as the optimal compound with a comparable profile to the inhaled once-daily long-acting ß2-adrenoceptor agonist indacaterol. On the basis of these data 2 was promoted as the backup development candidate to indacaterol from the Novartis LABA project.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2/administração & dosagem , Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Benzotiazóis/administração & dosagem , Benzotiazóis/farmacologia , Receptores Adrenérgicos beta 2/metabolismo , Administração por Inalação , Agonistas de Receptores Adrenérgicos beta 2/química , Animais , Benzotiazóis/química , Relação Dose-Resposta a Droga , Cobaias , Estrutura Molecular
5.
BMC Psychiatry ; 14: 15, 2014 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-24447428

RESUMO

BACKGROUND: Poor adherence to antipsychotic medication is a widespread problem, and the largest predictor of relapse in patients with psychosis. Electronic reminders are increasingly used to improve medication adherence for a variety of medical conditions, but have received little attention in the context of psychotic disorders. We aimed to explore the feasibility and acceptability of including short message service (SMS) medication reminders in the aftercare plan of service users discharged from inpatient care on maintenance antipsychotic medication. METHODS: We conducted a cross-sectional, trust-wide survey in the inpatient units of the Oxleas National Health Service (NHS) Foundation Trust in the UK between June 29 and August 3, 2012. Using a self-report questionnaire and the Drug Attitude Inventory, we examined inpatient attitudes towards antipsychotic drugs, past adherence to antipsychotic medication, frequency of mobile phone ownership, and interest in receiving SMS medication reminders upon discharge from the ward. Predictors of a patient's interest in receiving electronic reminders were examined using simple logistic regression models. RESULTS: Of 273 inpatients, 85 met eligibility criteria for the survey, showed decisional capacity, and agreed to participate. Of the 85 respondents, over a third (31-35%) admitted to have forgotten to take/collect their antipsychotic medication in the past, and approximately half (49%) to have intentionally skipped their antipsychotics or taken a smaller dose than prescribed. Male patients (55%), those with negative attitudes towards antipsychotics (40%), and those unsatisfied with the information they received on medication (35%) were approximately 3 to 4 times more likely to report past intentional poor adherence. The large majority of respondents (80-82%) reported having a mobile phone and knowing how to use SMS, and a smaller majority (59%) expressed an interest in receiving SMS medication reminders after discharge. No variable predicted a patient's interest in receiving electronic reminders of antipsychotics. CONCLUSIONS: Automatic SMS reminders of antipsychotic medication were acceptable to the majority of the survey respondents as an optional service offered upon discharge from inpatient care. Automatic electronic reminders deserve further investigation as a flexible, minimally invasive, cost-effective and broadly applicable tool that can potentially improve antipsychotic adherence and clinical outcomes.


Assuntos
Antipsicóticos/uso terapêutico , Adesão à Medicação , Transtornos Psicóticos/tratamento farmacológico , Sistemas de Alerta , Envio de Mensagens de Texto , Adulto , Estudos Transversais , Feminino , Humanos , Pacientes Internados/psicologia , Masculino , Pessoa de Meia-Idade , Recidiva , Inquéritos e Questionários , Reino Unido
6.
bioRxiv ; 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37662274

RESUMO

A diverse group of RNA viruses including Rabies, Polio, La Crosse, West Nile, Zika, Nipah, Eastern and Western equine encephalitis, Venezuelan equine encephalitis, Japanese encephalitis, and tick-borne encephalitis viruses have the ability to gain access to and replicate in the central nervous system (CNS), causing severe neurological disease. Current treatment for these patients is generally limited to supportive care. To address the need for a generalizable antiviral, we utilized a strategy of mutagenesis to limit virus replication. We evaluated ribavirin (RBV), favipiravir (FAV) and N 4 -hydroxycytidine (NHC) against La Crosse virus (LACV) which is the primary cause of pediatric arboviral encephalitis cases in North America. NHC was more potent than RBV or FAV in neuronal cells. Oral administration of molnupiravir (MOV), the 5'-isobutyryl prodrug of NHC, decreased neurological disease development by 32% following intraperitoneal (IP) infection of LACV. MOV also reduced disease by 23% when virus was administered intranasally (IN). NHC and MOV produced less fit viruses by incorporating predominantly G-to-A or C-to-U mutations. Furthermore, NHC also inhibited two other orthobunyaviruses, Jamestown Canyon virus and Cache Valley virus. Collectively, these studies indicate that NHC/MOV has therapeutic potential to inhibit virus replication and subsequent neurological disease caused by this neurotropic RNA virus.

7.
Cell Tissue Bank ; 13(1): 119-27, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21197583

RESUMO

A method of care for these infected nonunions is prolonged intravenous systemic antibiotic treatment and implantation of methyl methacrylate antibiotic carrier beads to delivery high local doses of antibiotics. This method requires a second surgery to remove the beads once the infection has cleared. Recent studies have investigated the use of biodegradable materials that have been impregnated with antibiotics as tools to treat bone infections. In the present study, human demineralized bone matrix (DBM) was investigated for its ability to be loaded with an antibiotic. The data presented herein demonstrates that this osteoinductive and biodegradable material can be loaded with gentamicin and release clinically relevant levels of the drug for at least 13 days in vitro. This study also demonstrates that the antibiotic loaded onto the graft has no adverse effects on the osteoinductive nature of the DBM as measured in vitro and in vivo. This bone void filler may represent a promising option for local antibiotic delivery in orthopedic applications.


Assuntos
Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Técnica de Desmineralização Óssea , Matriz Óssea/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Gentamicinas/administração & dosagem , Gentamicinas/farmacologia , Fosfatase Alcalina/metabolismo , Animais , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Cinética , Testes de Sensibilidade Microbiana , Osseointegração/efeitos dos fármacos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/enzimologia , Osteogênese/efeitos dos fármacos , Ratos , Staphylococcus aureus/efeitos dos fármacos
8.
Front Neural Circuits ; 16: 1002013, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36160949

RESUMO

Sudden unexpected death in epilepsy (SUDEP) accounts for the deaths of 8-17% of patients with epilepsy. Although the mechanisms of SUDEP are essentially unknown, one proposed mechanism is respiratory arrest initiated by a convulsive seizure. In mice, we have previously observed that extended apnea occurs during the tonic phase of seizures. Although often survived, tonic seizures became fatal when breathing did not immediately recover postictally. We also found that respiratory muscles were tonically contracted during the apnea, suggesting that muscle contraction could be the cause of apnea. In the present study, we tested the hypothesis that pyramidal neurons of the motor cortex drive motor units during the tonic phase, which produces apnea. Mice harboring the patient-derived N1768D point mutation of an Scn8a allele were crossed with transgenic mice such that inhibitory Designer Receptors Exclusively Activated by Designer Drugs (DREADD) receptors were selectively expressed in excitatory forebrain neurons. We then triggered audiogenic and hippocampal (HC) stimulated seizures under control conditions and when excitatory forebrain neurons were inhibited with the synthetic ligand Clozapine-N-Oxide (CNO). We found that inhibition with CNO was sufficient to increase seizure threshold of HC stimulated, but not audiogenic, seizures. In addition, regardless of seizure type, CNO nearly eliminated epileptiform activity that occurred proximal to the tonic phase; however, the seizure behaviors, notably the tonic phase and concomitant apnea, were unchanged. We interpret these results to indicate that while cortical neurons are likely critical for epileptogenesis and seizure initiation, the behavioral manifestations of tonic seizures are generated by neural circuitry in the mid- and/or hindbrain.


Assuntos
Clozapina , Drogas Desenhadas , Epilepsia , Morte Súbita Inesperada na Epilepsia , Animais , Apneia/genética , Modelos Animais de Doenças , Epilepsia/genética , Ligantes , Camundongos , Camundongos Transgênicos , Canal de Sódio Disparado por Voltagem NAV1.6 , Óxidos , Prosencéfalo , Convulsões/genética
9.
Bioorg Med Chem Lett ; 20(17): 5302-7, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20655218

RESUMO

The chiral synthesis of a 4-hydroxybenzothiazolone based series of beta(2)-adrenoceptor agonists is described. Using this methodology a library of N-substituted analogues were prepared for the rapid identification of leads with the potential to be fast onset and long-acting inhaled bronchodilators with improved therapeutic margins. The design of the library to achieve the targeted profile was based upon lipophilicity and metabolism based hypotheses. This approach identified beta-phenethyl, alpha-substituted cyclopentyl and monoterpene N-substituents to be of particular interest for further evaluation, as exemplified by structures 19, 29 and 33, respectively.


Assuntos
Antagonistas de Receptores Adrenérgicos beta 2/uso terapêutico , Broncodilatadores/uso terapêutico , Tiazóis/uso terapêutico , Administração por Inalação , Antagonistas de Receptores Adrenérgicos beta 2/farmacologia , Broncodilatadores/administração & dosagem , Broncodilatadores/farmacologia , Tiazóis/farmacologia
10.
PLoS One ; 15(7): e0232507, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645007

RESUMO

Sex-related differences in cardiovascular diseases are highly complex in humans and model-dependent in experimental laboratory animals. The objective of this work was to comprehensively investigate key sex differences in the response to acute and prolonged adrenergic stimulation in C57Bl/6NCrl mice. Cardiac function was assessed by trans-thoracic echocardiography before and after acute adrenergic stimulation (a single sub-cutaneous dose of isoproterenol 10 mg/kg) in 15 weeks old male and female C57Bl/6NCrl mice. Thereafter, prolonged adrenergic stimulation was achieved by sub-cutaneous injections of isoproterenol 10 mg/kg/day for 14 days in male and female mice. Cardiac function and morphometry were assessed by trans-thoracic echocardiography on the 15th day. Thereafter, the mice were euthanized, and the hearts were collected. Histopathological analysis of myocardial tissue was performed after staining with hematoxylin & eosin, Masson's trichrome and MAC-2 antibody. Gene expression of remodeling and fibrotic markers was assessed by real-time PCR. Cardiac function and morphometry were also measured before and after isoproterenol 10 mg/kg/day for 14 days in groups of gonadectomized male and female mice and sham-operated controls. In the current work, there were no statistically significant differences in the positive inotropic and chronotropic effects of isoproterenol between male and female C57Bl/6NCrl. After prolonged adrenergic stimulation, there was similar degree of cardiac dysfunction, cardiac hypertrophy, and myocardial fibrosis in male and female mice. Similarly, prolonged isoproterenol administration induced hypertrophic and fibrotic genes in hearts of male and female mice to the same extent. Intriguingly, gonadectomy of male and female mice did not have a significant impact on isoproterenol-induced cardiac dysfunction as compared to sham-operated animals. The current work demonstrated lack of significant sex-related differences in isoproterenol-induced cardiac hypertrophy, dysfunction, and fibrosis in C57Bl/6NCrl mice. This study suggests that female sex may not be sufficient to protect the heart in this model of isoproterenol-induced cardiac dysfunction and underscores the notion that sexual dimorphism in cardiovascular diseases is highly model-dependent.


Assuntos
Cardiopatias/fisiopatologia , Caracteres Sexuais , Animais , Biomarcadores/metabolismo , Cardiomegalia/induzido quimicamente , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Cardiomegalia/fisiopatologia , Modelos Animais de Doenças , Ecocardiografia , Feminino , Cardiopatias/induzido quimicamente , Cardiopatias/metabolismo , Cardiopatias/patologia , Isoproterenol/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ovariectomia
11.
Am J Speech Lang Pathol ; 17(2): 139-49, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18448601

RESUMO

PURPOSE: The aims of this study were to evaluate the efficacy of telehealth delivery of the Lidcombe Program of Early Stuttering Intervention, compared with a control group, and to determine the number of children who could be regarded as "responders." METHOD: A speech-language pathologist provided telehealth delivery of the Lidcombe Program during telephone consultations with parents in their homes, remote from the clinic. The study design was an open plan, parallel group, randomized controlled trial with blinded outcome assessment. Children in the no-treatment control group who were still stuttering after 9 months then received the same treatment. The primary outcome measure was frequency of stuttering, gathered from audiotape recordings of participants' conversational speech in everyday, nontreatment situations, before and after treatment. RESULTS: Analysis of covariance showed a 73% decrease in frequency of stuttering at 9 months after randomization in the treatment group, as compared with the control group (95% confidence interval = 25%-90%, p = .02). Measures of treatment time showed that telehealth delivery of the Lidcombe Program requires around 3 times more resources than standard presentation. CONCLUSIONS: Telehealth delivery of the Lidcombe Program is an efficacious treatment for preschool children who cannot receive the standard, clinic-based Lidcombe Program. Avenues for improving efficiency are considered.


Assuntos
Intervenção Educacional Precoce , Consulta Remota , Fonoterapia/métodos , Gagueira/reabilitação , Pré-Escolar , Comportamento do Consumidor , Feminino , Seguimentos , Humanos , Masculino , Pais/educação , Medida da Produção da Fala , Gravação em Fita , Telefone , Gravação em Vídeo
12.
Endocrinology ; 148(2): 493-500, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17095597

RESUMO

For animals in the wild, survival depends on being able to detect and respond rapidly to danger by switching from risky (e.g. conspicuous courtship) to survival-oriented behaviors. Very little is known about the hormonal or neuroendocrine mechanisms that control the rapid switch in behavioral state that occurs when an animal detects threats or other stressors. Prior studies with rough-skinned newts (Taricha granulosa), an amphibian model, found that stress-induced suppression of male sexual behaviors (amplectic clasping) involves corticosterone (CORT) and that this steroid hormone uses a novel membrane receptor and modulates the responsiveness of medullary neurons in clasp-controlling neural circuits. We provide evidence that this rapid suppression of male sex behaviors, when induced by either acute stress or CORT administration, involves activation of endocannabinoids signaling in the hindbrain. In a series of behavioral studies, administration of a cannabinoid antagonist, AM281, blocked the suppressive effects of exposure to acute stress or an injection of CORT on the performance of clasping behaviors in sexually active males. Similarly, in electrophysiological studies, prior treatment with AM281 blocked CORT-induced suppression of spontaneous neuronal activity and sensory responsiveness of hindbrain neurons in clasp-controlling neural circuits. These data suggest that, in response to acute stress, elevated CORT concentration increases endocannabinoid signaling in the hindbrain and alters sexual behaviors by modulating the excitability of medullary circuits.


Assuntos
Moduladores de Receptores de Canabinoides/metabolismo , Corticosterona/farmacologia , Endocanabinoides , Comportamento Sexual Animal/efeitos dos fármacos , Estresse Fisiológico/psicologia , Doença Aguda , Animais , Canabinoides/antagonistas & inibidores , Corticosterona/sangue , Eletrofisiologia , Masculino , Bulbo/efeitos dos fármacos , Bulbo/fisiopatologia , Morfolinas/farmacologia , Neurônios/efeitos dos fármacos , Pirazóis/farmacologia , Radioimunoensaio , Salamandridae , Estresse Fisiológico/sangue , Estresse Fisiológico/fisiopatologia
13.
Br J Nurs ; 16(11): S22-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17577191

RESUMO

This article presents the results of a previously unexplored aspect of qualitative leg ulcer research. The study has examined the lived experience and cultural illness explanations of a sample of British-Indian patients living with leg and foot ulceration. Semi-structured interviews were used to collect data from 16 Indian patients drawn from leg ulcer clinics and district nursing lists in Ealing Primary Care Trust and Hounslow Primary Care Trust. Eight respondents had venous ulceration, seven were diabetic and had ulcers of arterial aetiology, and one had ulceration due to lymphoedema. Popular perceptions of the cause of leg ulceration were influenced by the humoral theories of balance and imbalance. Other explanations included poor circulation, lowered immunity, bad blood, being cursed and doing something wrong in a past life or this life.


Assuntos
Atitude Frente a Saúde/etnologia , Comportamentos Relacionados com a Saúde/etnologia , Conhecimentos, Atitudes e Prática em Saúde , Úlcera da Perna/etnologia , Adaptação Psicológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Causalidade , Diversidade Cultural , Feminino , Homeopatia , Humanos , Índia/etnologia , Úlcera da Perna/etiologia , Úlcera da Perna/prevenção & controle , Masculino , Ayurveda , Medicina Unani , Pessoa de Meia-Idade , Narração , Pesquisa Metodológica em Enfermagem , Pesquisa Qualitativa , Qualidade de Vida/psicologia , Autocuidado/métodos , Autocuidado/psicologia , Inquéritos e Questionários , Yoga
14.
J Comp Neurol ; 491(4): 381-9, 2005 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-16175544

RESUMO

Arginine8 vasotocin (AVT), a neurohypophyseal peptide in nonmammalian vertebrates, plays a key role in the regulation of social behaviors related to reproduction. In male roughskin newts (Taricha granulosa), AVT is an important facilitator of several reproductive behaviors, including courtship clasping of females. Although AVT is known to act in certain brain regions and AVT receptors have been localized to some extent, specific target neurons for this peptide have not been identified in any species. Internalization of a receptor-specific conjugate of AVT and the fluorescent dye Oregon green was used to identify AVT target cells in the medulla of male roughskin newts. Medullary neurons are of interest because they appear to mediate facilitation of clasping by AVT. Direct application of AVT-Oregon green to the fourth ventricular surface of the medulla in vivo resulted in conjugate internalization by a widespread population of medullary neurons, particularly in the medial reticular formation and nuclei of cranial nerves V, VII, VIII, IX, and X. Some fourth-ventricle ependymal cells were also labeled. Reticulospinal neurons, which play an important role in clasping, were identified by retrograde labeling with tetramethylrhodamine dextran amine. AVT-Oregon green was internalized by 72% of these neurons. These results show that AVT can directly affect a very large and diverse medullary neuronal population, which may underlie the peptide's role in multiple neuroendocrinological processes, including autonomic and behavioral regulation. Selectivity of the AVT action may arise through interactions between AVT and steroids such as corticosterone.


Assuntos
Bulbo/citologia , Neurônios/citologia , Salamandridae/anatomia & histologia , Comportamento Sexual Animal/fisiologia , Vasotocina/metabolismo , Animais , Fluoresceínas , Masculino , Microscopia Confocal
16.
Curr Top Med Chem ; 4(8): 863-70, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15078217

RESUMO

A class of potent, selective adenosine A(3) receptor antagonists was obtained via optimisation of the screening hit N-[4-(4-methoxyphenyl)-thiazol-2-yl]-acetamide. Structural modifications of this hit revealed very quickly that a 5-(pyridin-4-yl) substituent on the 2-aminothiazole ring was optimal for high potency at the adenosine A(3) receptor. Structure activity relationship studies led to both potent and selective A(3) receptor antagonists, including N-[5-pyridin-4-yl-4-(3,4,5-trimethoxyphenyl)-thiazol-2-yl]-acetamide, a highly potent aden-osine A(3) receptor antagonist with greater than 100- fold selectivity against the related adenosine receptors. As well as demonstrating selective in vitro binding on the human A(3) adenosine receptor, this compound was also shown to selectively block the rat A(3) receptor in vivo. This important new compound can be readily synthesised in four steps from commercially available starting materials.


Assuntos
Acetamidas/química , Antagonistas do Receptor A3 de Adenosina , Tiazóis/química , Acetamidas/síntese química , Acetamidas/farmacologia , Animais , Desenho de Fármacos , Humanos , Ratos , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/farmacologia
17.
J Med Chem ; 46(16): 3508-13, 2003 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-12877589

RESUMO

In a program aimed at the development of neurokinin antagonists, N-[(R,R)-(E)-1-(3,4-dichlorobenzyl)-3-(2-oxoazepan-3-yl)carbamoyl]allyl-N-methyl-3,5-bis(trifluoromethyl)benzamide (1, DNK333) has been discovered as a potent and balanced neurokinin (tachykinin) NK(1)/NK(2) receptor antagonist. Enantiomerically pure (>99.5% ee) 1 can be prepared in 6 + 1 synthetic steps starting from commercially available optically active BOC-d-3,4-dichlorophenylalanine in an overall yield of ca. 25-30%. 1 showed potent affinities to cloned human NK(1) (pK(i) = 8.38) and NK(2) (pK(i) = 8.02) receptors. When 1 was compared to the other possible three diastereoisomers, it could be demonstrated that only the R,R-isomer (1) exhibits potent and balanced affinity for the cloned human NK(1) and NK(2) receptors. 1 exhibited favorable pharmacokinetic properties in guinea pigs following oral administration and demonstrated in vivo activity in pharmacological models of substance P- and neurokinin A (NKA)-induced bronchoconstriction in guinea pigs after intravenous and in squirrel monkeys after oral application.


Assuntos
Compostos Aza/síntese química , Benzamidas/síntese química , Antagonistas dos Receptores de Neurocinina-1 , Receptores da Neurocinina-2/antagonistas & inibidores , Administração Oral , Animais , Compostos Aza/química , Compostos Aza/farmacologia , Benzamidas/química , Benzamidas/farmacologia , Disponibilidade Biológica , Broncoconstrição/efeitos dos fármacos , Células CHO , Cricetinae , Cobaias , Humanos , Masculino , Saimiri , Estereoisomerismo , Relação Estrutura-Atividade
18.
Naunyn Schmiedebergs Arch Pharmacol ; 367(2): 104-8, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12595950

RESUMO

The neurokinin (NK) receptors, NK(1) and NK(2), which are activated by substance P (SP) and NKA, have been identified as potential therapeutic targets in irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). Here we have investigated the effects of a novel dual NK(1) and NK(2) receptor antagonist, namely DNK333 upon responses elicited by [Sar(9), Met(O(2))(11)]-SP (SMSP) and [betaAla(8)]-NKA(4-10) in isolated human colon mucosa mounted in Ussing chambers. A selective NK(1) receptor antagonist, SR140333 and NK(2) receptor antagonist, SR48968 have been tested for comparison. Additions of SMSP (100 nM) or [betaAla(8)]-NKA(4-10) (100 nM) increased basal short-circuit current and responses to both peptides were inhibited by DNK333, while SR140333 only inhibited SMSP and SR48968 blocked only [betaAla(8)]-NKA(4-10) responses. SR140333 did not attenuate [betaAla(8)]-NKA(4-10) effects and SR48968 had no effect upon SMSP responses. Carbachol (1 micro M) responses were not altered by any of the three NK antagonists. We conclude that activation of either NK(1) or NK(2) receptors can stimulate epithelial ion transport in human colon mucosa and that the novel dual antagonist, DNK333 may be of potential therapeutic interest in the treatment of IBD and IBS.


Assuntos
Mucosa Intestinal/efeitos dos fármacos , Antagonistas dos Receptores de Neurocinina-1 , Receptores da Neurocinina-2/antagonistas & inibidores , Idoso , Compostos Aza/farmacologia , Benzamidas/farmacologia , Colo/efeitos dos fármacos , Colo/fisiologia , Feminino , Humanos , Técnicas In Vitro , Mucosa Intestinal/metabolismo , Transporte de Íons/efeitos dos fármacos , Masculino , Técnicas de Patch-Clamp , Piperidinas/farmacologia , Quinuclidinas/farmacologia
20.
J Biomater Appl ; 26(4): 491-506, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20819915

RESUMO

Infected bone defects and osteomyelitis are encountered frequently in trauma cases. Currently, the standard of care for osteomyelitis cases is prolonged systemic antibiotic therapy and implantation of antibiotic carrier beads. However, this method requires a secondary surgery to remove the beads after the infection has cleared. In the present study a common bone void filler was investigated for its ability to be infused with an antibiotic. This study demonstrates that the xenograft material tested can be loaded with gentamicin and release clinically relevant levels of the drug for at least 14 days in vitro allowing for the inhibition of bacterial growth on the graft. This study also demonstrates that the levels of gentamicin released did not have an adverse effect on primary osteoblast cell proliferation or ability to generate alkaline phosphatase. This bone void filler may represent a viable alternative to current methods of local antibiotic delivery in orthopedic applications.


Assuntos
Antibacterianos/administração & dosagem , Sistemas de Liberação de Medicamentos , Osteomielite/tratamento farmacológico , Fosfatase Alcalina/metabolismo , Animais , Antibacterianos/farmacocinética , Materiais Biocompatíveis , Transplante Ósseo , Bovinos , Adesão Celular/efeitos dos fármacos , Proliferação de Células , Preparações de Ação Retardada , Gentamicinas/administração & dosagem , Gentamicinas/farmacocinética , Técnicas In Vitro , Teste de Materiais , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteomielite/enzimologia , Osteomielite/microbiologia , Osteomielite/patologia , Ratos , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Transplante Heterólogo
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