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1.
Environ Toxicol Chem ; 40(6): 1713-1725, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33646621

RESUMO

The present study investigates the bioaccumulation of the insensitive munition compounds 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO), developed for future weapons systems to replace current munitions containing sensitive explosives. The earthworm Eisenia andrei was exposed to sublethal concentrations of DNAN or NTO amended in Sassafras sandy loam. Chemical analysis indicated that 2- and 4-amino-nitroanisole (2-ANAN and 4-ANAN, respectively) were formed in DNAN-amended soils. The SumDNAN (sum of DNAN, 2-ANAN, and 4-ANAN concentrations) in soil decreased by 40% during the 14-d exposure period. The SumDNAN in the earthworm body residue increased until day 3 and decreased thereafter. Between days 3 and 14, there was a 73% decrease in tissue uptake that was greater than the 23% decrease in the soil concentration, suggesting that the bioavailable fraction may have decreased over time. By day 14, the DNAN concentration accounted for only 45% of the SumDNAN soil concentration, indicating substantial DNAN transformation in the presence of earthworms. The highest bioaccumulation factor (BAF; the tissue-to-soil concentration ratio) was 6.2 ± 1.0 kg/kg (dry wt) on day 3 and decreased to 3.8 ± 0.8 kg/kg by day 14. Kinetic studies indicated a BAF of 2.3 kg/kg, based on the earthworm DNAN uptake rate of 2.0 ± 0.24 kg/kg/d, compared with the SumDNAN elimination rate of 0.87 d-1 (half-life = 0.79 d). The compound DNAN has a similar potential to bioaccumulate from soil compared with trinitrotoluene. The NTO concentration in amended soil decreased by 57% from the initial concentration (837 mg NTO/kg dry soil) during 14 d, likely due to the formation of unknown transformation products. The bioaccumulation of NTO was negligible (BAF ≤ 0.018 kg/kg dry wt). Environ Toxicol Chem 2021;40:1713-1725. © 2021 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.


Assuntos
Substâncias Explosivas , Oligoquetos , Poluentes do Solo , Animais , Anisóis/análise , Anisóis/toxicidade , Bioacumulação , Substâncias Explosivas/toxicidade , Cinética , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
2.
J Clin Microbiol ; 52(11): 3845-52, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25122860

RESUMO

The identification and elimination of persistently infected (PI) cattle are the most effective measures for controlling bovine pestiviruses, including bovine viral diarrhea virus (BVDV) and the emerging HoBi-like viruses. Here, colostrum-deprived calves persistently infected with HoBi-like pestivirus (HoBi-like PI calves) were generated and sampled (serum, buffy coat, and ear notches) on the day of birth (DOB) and weekly for 5 consecutive weeks. The samples were subjected to diagnostic tests for BVDV--two reverse transcriptase PCR (RT-PCR) assays, two commercial real-time RT quantitative PCR (RT-qPCR), two antigen capture enzyme-linked immunosorbent assays (ACE), and immunohistochemistry (IHC)--and to HoBi-like virus-specific RT-PCR and RT-qPCR assays. The rate of false negatives varied among the calves. The HoBi-like virus-specific RT-PCR detected HoBi-like virus in 83%, 75%, and 87% of the serum, buffy coat, and ear notch samples, respectively, while the HoBi-like RT-qPCR detected the virus in 83%, 96%, and 62%, respectively. In comparison, the BVDV RT-PCR test had a higher rate of false negatives in all tissue types, especially for the ear notch samples (missing detection in at least 68% of the samples). The commercial BVDV RT-qPCRs and IHC detected 100% of the ear notch samples as positive. While ACE based on the BVDV glycoprotein E(rns) detected infection in at least 87% of ear notches, no infections were detected using NS3-based ACE. The BVDV RT-qPCR, ACE, and IHC yielded higher levels of detection than the HoBi-like virus-specific assays, although the lack of differentiation between BVDV and HoBi-like viruses would make these tests of limited use for the control and/or surveillance of persistent HoBi-like virus infection. An improvement in HoBi-like virus tests is required before a reliable HoBi-like PI surveillance program can be designed.


Assuntos
Técnicas de Laboratório Clínico/métodos , Testes Diagnósticos de Rotina/métodos , Infecções por Pestivirus/veterinária , Pestivirus/isolamento & purificação , Animais , Buffy Coat/virologia , Bovinos , Orelha/virologia , Reações Falso-Negativas , Imunoensaio/métodos , Imuno-Histoquímica/métodos , Técnicas de Diagnóstico Molecular/métodos , Infecções por Pestivirus/diagnóstico , Soro/virologia
3.
Psychol Serv ; 11(3): 295-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24588106

RESUMO

A team of clinicians at a small rural Veterans' Health Administration (VHA) medical center piloted a brief psychological intervention for posttraumatic stress in a primary mental health care setting. Symptom measures were completed by veterans before and after receiving the brief trauma treatment (BTT), and were then analyzed using paired t tests. In our uncontrolled study, we found a statistically insignificant improvement in symptoms of posttraumatic stress disorder, though there were statistically significant, but not clinically significant, improvements in depression and general anxiety. The intervention may enhance subsequent specialty mental health engagement. Fifty-one veterans (62.20%) went on to receive psychotherapy in a specialty mental health setting, which represents a substantial increase in specialty psychotherapy engagement compared to reports elsewhere in the literature. Lack of controlled comparison precludes definitive conclusions, but the current preliminary results support future studies of brief psychological interventions in primary care settings, including randomized controlled comparisons.


Assuntos
Atenção Primária à Saúde , Psicoterapia Breve/métodos , Transtornos de Estresse Pós-Traumáticos/terapia , Adulto , Idoso , Humanos , Masculino , Saúde Mental , Pessoa de Meia-Idade , Transtornos de Estresse Pós-Traumáticos/psicologia , Resultado do Tratamento , Veteranos/psicologia , Adulto Jovem
4.
Theriogenology ; 79(6): 1010-8, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23465288

RESUMO

Retinoic acid is an important regulator of cellular proliferation and differentiation. The action of retinoic acid is mediated by retinoic acid receptors (RARs) and the retinoid X receptors. The objective was to elucidate the protein localization and expression of RARα, RARß, and RARγ in bull and dog sperm. Bull and dog sperm were subjected to an immunostaining procedure to determine presence of RARα, RARß, and RARγ. We concluded that all three receptors were present in different regions of bull and dog sperm at varying levels. Protein expression in bull and dog sperm lysates was investigated using protein dot-blot analyses. The protein levels of RARα and RARγ were higher than the protein level of RARß in bull and dog sperm. Protein sequences of RARα, RARß, and RARγ for bull and dog were 98%, 89%, and 98%, respectively, on similarity alignment. In conclusion, the presence of RARα, RARß, and RARγ receptors supported their role in sperm structure and function.


Assuntos
Receptores do Ácido Retinoico/análise , Espermatozoides/química , Animais , Bovinos , Cães , Masculino , Dados de Sequência Molecular , Receptores do Ácido Retinoico/metabolismo , Receptor alfa de Ácido Retinoico , Alinhamento de Sequência , Análise de Sequência de Proteína , Receptor gama de Ácido Retinoico
5.
Anim Reprod Sci ; 136(1-2): 139-45, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23182466

RESUMO

The objective of this study was to evaluate the effect of addition of egg yolk (EY) or soy lecithin (SL) based extenders on dog sperm parameters during 10days storage at 5°C. Four ejaculates of pooled semen from three Mongrel dogs were divided into three aliquots and extended to a final concentration of 200 million sperm/mL using following non-commercial extenders: egg yolk extender (EYE) group - semen+20% Tris-EYE; soy lecithin (SL) group 1 - semen+SL extender with 0.04% SL; SL group 2 - semen+SL extender 0.4% SL. The extended semen samples were stored at 5°C and were evaluated for sperm mitochondrial membrane potential (MMP), plasma membrane integrity (%PMI) and computer assisted sperm analyzer (CASA) sperm motility parameters on days 0, 1, 2, 3, 4, 7 and 10. The extender, days of storage and extender×days of storage affected the MMP, %PMI and CASA sperm motility parameters (P<0.05). The addition of 0.4% SL extender reduced the speed of deterioration of sperm parameters evaluated in this study compared to EY and 0.04% SL extenders (P<0.05). In conclusion, the addition of 0.4% SL extender enhanced sperm preservation based on the variables evaluated in the present study compared to EYE and 0.04% SL extenders and plausibly preserves sperm quality longer.


Assuntos
Membrana Celular/efeitos dos fármacos , Criopreservação/veterinária , Crioprotetores/farmacologia , Cães , Preservação do Sêmen/veterinária , Espermatozoides/efeitos dos fármacos , Animais , Masculino , Membranas Mitocondriais/efeitos dos fármacos , Manejo de Espécimes , Motilidade dos Espermatozoides/efeitos dos fármacos , Motilidade dos Espermatozoides/fisiologia , Espermatozoides/citologia , Espermatozoides/fisiologia
6.
J Nerv Ment Dis ; 200(6): 520-5, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22652617

RESUMO

We studied differences in diagnostic stability between patients with full and patients with partial posttraumatic stress disorder (PTSD). We collected self-reported symptoms of PTSD, anxiety, depression, and functioning at a Veterans Affairs mental health clinic (n = 1962). We classified patients as meeting full or partial PTSD based upon their initial assessment. We performed Kaplan-Meier survival analysis to compare stability of diagnosis over time and Cox proportional hazards models to understand how comorbid symptoms and level of functioning confounded the relationship. We performed a chart review to examine differences in treatment received by the two groups. Patients in the partial PTSD group lost their diagnosis significantly faster and at significantly higher rates than did patients with full PTSD. Comorbid symptoms contributed significantly to this difference. Mental health treatments delivered to the two groups were similar. These diagnoses appear to be different, suggesting that people with partial PTSD may benefit from a different clinical approach.


Assuntos
Distúrbios de Guerra/classificação , Distúrbios de Guerra/diagnóstico , Transtornos de Estresse Pós-Traumáticos/classificação , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Veteranos/psicologia , Adulto , Nível de Alerta , Distúrbios de Guerra/epidemiologia , Distúrbios de Guerra/psicologia , Comorbidade , Estudos Transversais , Mecanismos de Defesa , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Determinação da Personalidade/estatística & dados numéricos , Modelos de Riscos Proporcionais , Psicometria/estatística & dados numéricos , Psicotrópicos/uso terapêutico , Reprodutibilidade dos Testes , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Resultado do Tratamento , Estados Unidos
7.
J Chromatogr A ; 1218(27): 4219-25, 2011 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-21247580

RESUMO

The ability to detect and identify the physiochemical form of contaminants in the environment is important for degradation, fate and transport, and toxicity studies. This is particularly true of nanomaterials that exist as discrete particles rather than dissolved or sorbed contaminant molecules in the environment. Nanoparticles will tend to agglomerate or dissolve, based on solution chemistry, which will drastically affect their environmental properties. The current study investigates the use of field flow fractionation (FFF) interfaced to inductively coupled plasma-mass spectrometry (ICP-MS) as a sensitive and selective method for detection and characterization of silver nanoparticles. Transmission electron microscopy (TEM) is used to verify the morphology and primary particle size and size distribution of precisely engineered silver nanoparticles. Subsequently, the hydrodynamic size measurements by FFF are compared to dynamic light scattering (DLS) to verify the accuracy of the size determination. Additionally, the sensitivity of the ICP-MS detector is demonstrated by fractionation of µg/L concentrations of mixed silver nanoparticle standards. The technique has been applied to nanoparticle suspensions prior to use in toxicity studies, and post-exposure biological tissue analysis. Silver nanoparticles extracted from tissues of the sediment-dwelling, freshwater oligochaete Lumbriculus variegatus increased in size from approximately 31-46nm, indicating a significant change in the nanoparticle characteristics during exposure.


Assuntos
Fracionamento por Campo e Fluxo/métodos , Espectrometria de Massas/métodos , Nanopartículas Metálicas/química , Prata/química , Análise de Variância , Animais , Luz , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Oligoquetos , Tamanho da Partícula , Reprodutibilidade dos Testes , Espalhamento de Radiação , Sensibilidade e Especificidade , Estatísticas não Paramétricas
8.
Anaesth Intensive Care ; 35(1): 105-9, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17323676

RESUMO

We report a case of stridor in a 32 year old woman. Initial laryngoscopy demonstrated adduction of the vocal cords on inspiration, which reverted to abduction on induction of general anaesthesia. The airway was structurally normal. The most likely diagnosis was paradoxical vocal cord motion, a condition in which psychological stress can precipitate respiratory symptoms and signs due to involuntary adduction of the vocal cords during inspiration. Its importance to the anaesthetist lies in its ability to masquerade as a serious airway or respiratory condition.


Assuntos
Rouquidão/terapia , Sons Respiratórios/diagnóstico , Prega Vocal/fisiopatologia , Adulto , Transtorno Conversivo/diagnóstico , Emergências , Feminino , Rouquidão/etiologia , Rouquidão/psicologia , Humanos , Intubação , Laringoscopia , Recusa do Paciente ao Tratamento
9.
J Cancer Educ ; 20(2): 103-7, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16083374

RESUMO

BACKGROUND: The Bridge to Better Health (BRIDGE) project is a program that focuses on providing rural high school youth with motivation, knowledge, and skills essential to cancer prevention. In this pilot intervention, we used instruction in personal health genealogy as a means of increasing awareness and knowledge of health risk and motivation to change several screening and cancer-related behaviors. METHODS: We administered a Bridge to Better Health survey to 173 ninth- and 10th-grade students from a rural Southeastern Virginia high school before and after delivery of the BRIDGE pilot intervention. RESULTS: Significant preintervention to postintervention changes were observed for general genealogy knowledge, personal health genealogy, self-efficacy, and intention to practice self-examinations (breast, testicular, and skin) and eating a high-fiber and low-fat diet. CONCLUSION: These project results demonstrate the importance of theory-driven interventions for increasing cancer knowledge and changing cancer-related dietary and screening behaviors.


Assuntos
Educação em Saúde/métodos , Conhecimentos, Atitudes e Prática em Saúde , Neoplasias/prevenção & controle , Linhagem , População Rural , Adolescente , Feminino , Humanos , Masculino
10.
J Neuroendocrinol ; 14(12): 963-9, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12472877

RESUMO

Dominant subordinate relationships are formed as the result of social conflict and are maintained at least in part by communication. At this time, little is known about the neural mechanisms that are responsible for coordinating the social behaviours (e.g. aggression) that occur in association with the formation and maintenance of these relationships. The purpose of the present study was to investigate the role of oxytocin (OXT) within the medial preoptic anterior hypothalamic continuum (MPOA-AH) in the control of aggression in female hamsters. OXT injected into the MPOA-AH immediately before testing significantly reduced the duration of aggression in a dose-dependent manner. Injection of an OXT antagonist 30 min before testing significantly increased the duration of aggression. In contrast, the duration of aggression was not altered when hamsters were tested either 30 min after injection of OXT or immediately following injection of an OXT-antagonist. These data support the hypothesis that OXT release within the MPOA-AH regulates social behaviours important in the formation and maintenance of dominant subordinate relationships in female hamsters.


Assuntos
Agressão/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Ocitocina/farmacologia , Animais , Cricetinae , Feminino , Hipotálamo/fisiologia , Ocitocina/antagonistas & inibidores
11.
Neuroscience ; 109(4): 767-72, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11927158

RESUMO

The type of social behavior displayed by an individual is profoundly influenced by its immediate social environment or context and its prior social experience. Although oxytocin is important in the expression of social behavior in several species, it is not known if social factors alter the ability of oxytocin to influence behavior. The purpose of the present study was to test the hypothesis that social experience and social context alter the ability of oxytocin to regulate flank marking (a form of scent marking) in female Syrian hamsters. Oxytocin was microinjected into the medial preoptic anterior hypothalamic continuum (MPOA-AH) of socially experienced, dominant female hamsters which were then tested with either a subordinate partner, with a novel partner, or alone. Oxytocin induced flank marking in a dose-dependent manner but only when the experienced dominant hamsters were tested with their familiar, subordinate partners. Oxytocin did not induce flank marking when injected into socially naive female hamsters that were tested with an opponent or alone. In males, by contrast, oxytocin induced flank marking in dominant hamsters when they were tested with their subordinate partner or alone. These data support the hypothesis that social experience and social context interact to regulate the ability of oxytocin to stimulate flank marking by its actions in the MPOA-AH in female hamsters.


Assuntos
Núcleo Hipotalâmico Anterior/metabolismo , Comportamento Animal/fisiologia , Mesocricetus/metabolismo , Ocitocina/metabolismo , Área Pré-Óptica/metabolismo , Caracteres Sexuais , Predomínio Social , Animais , Núcleo Hipotalâmico Anterior/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Cricetinae , Sinais (Psicologia) , Feminino , Aprendizagem/efeitos dos fármacos , Aprendizagem/fisiologia , Masculino , Ocitocina/farmacologia , Área Pré-Óptica/efeitos dos fármacos
12.
Am J Physiol Cell Physiol ; 280(4): C807-13, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11245597

RESUMO

Flavonoids, polyphenolic compounds that exist widely in plants, inhibit cell proliferation and increase cell differentiation in many cancerous and noncancerous cell lines. Because terminal differentiation of preadipocytes to adipocytes depends on proliferation of both pre- and postconfluent preadipocytes, we predicted that flavonoids would inhibit adipogenesis in the 3T3-L1 preadipocyte cell line. The flavonoids genistein and naringenin inhibited proliferation of preconfluent preadipocytes in a time- and dose-dependent manner. When added to 2-day postconfluent preadipocytes at the induction of differentiation, genistein inhibited mitotic clonal expansion, triglyceride accumulation, and peroxisome proliferator-activated receptor-gamma expression, but naringenin had no effect. The antiadipogenic effect of genistein was not due to inhibition of insulin receptor subtrate-1 tyrosine phosphorylation. When added 3 days after induction of differentiation, neither flavonoid inhibited differentiation. In fully differentiated adipocytes, genistein increased basal and epinephrine-induced lipolysis, but naringenin had no significant effects. These data demonstrate that genistein and naringenin, despite structural similarity, have differential effects on adipogenesis and adipocyte lipid metabolism.


Assuntos
Adipócitos/citologia , Antineoplásicos/farmacologia , Flavanonas , Flavonoides/farmacologia , Genisteína/farmacologia , Lipólise/efeitos dos fármacos , Células 3T3 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Antagonistas de Estrogênios/farmacologia , Proteínas Substratos do Receptor de Insulina , Camundongos , Mitose/efeitos dos fármacos , Fosfoproteínas/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Fatores de Transcrição/metabolismo
13.
Genomics ; 71(2): 182-91, 2001 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-11161812

RESUMO

Stearoyl-coenzyme A (CoA) desaturase (SCD) is a key enzyme involved in the conversion of saturated fatty acids into monounsaturated fatty acids. Previously, two members of this gene family, namely, Scd1 and Scd2, have been reported. Here we report the identification and characterization of a novel member of this family, Scd3, whose expression is restricted to mouse skin, specifically to the sebaceous gland. The Scd3 gene codes for a transcript of approximately 4.9 kb with an open reading frame that results in a 359-amino-acid protein. Scd3 shares 91 and 88% identity in the protein-coding region with Scd1 and Scd2, respectively, and maps to mouse chromosome 19 in very close proximity to Scd1 and Scd2. Unlike Scd1, Scd3 expression is higher in male mouse skin than in female mouse skin. The promoter sequence of Scd3 reveals similarity with Scd1 in the proximal region but also possesses several distinctive features including the polyunsaturated fatty acid-response element. Scd3 is expressed in the skin of young asebia mutant mice (Scd1(ab2J)/Scd1(ab2J)) in the absence of Scd1. Scd3 expression changes during the mouse hair cycle but not as dramatically as Scd1. The tissue-specific and sex-dependent expression of Scd3 suggests the presence of gene- and hormonal-specific control mechanisms.


Assuntos
Pele/enzimologia , Estearoil-CoA Dessaturase/genética , Regiões 5' não Traduzidas/genética , Animais , Sequência de Bases , Mapeamento Cromossômico , Feminino , Biblioteca Gênica , Masculino , Camundongos , Camundongos Mutantes , Dados de Sequência Molecular , Família Multigênica/genética , Fases de Leitura Aberta , Regiões Promotoras Genéticas/genética , Elementos de Resposta , Glândulas Sebáceas/química , Alinhamento de Sequência , Fatores Sexuais , Estearoil-CoA Dessaturase/metabolismo
14.
Nucleic Acids Res ; 29(1): 111-3, 2001 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11125063

RESUMO

The PlantsP database is a curated database that combines information derived from sequences with experimental functional genomics information. PlantsP focuses on plant protein kinases and protein phosphatases. The database will specifically provide a resource for information on a collection of T-DNA insertion mutants (knockouts) in each protein kinase and phosphatase in Arabidopsis thaliana. PlantsP also provides a curated view of each protein that includes a comprehensive annotation of functionally related sequence motifs, sequence family definitions, alignments and phylogenetic trees, and descriptive information drawn directly from the literature. PlantsP is available at http://PlantsP.sdsc.edu.


Assuntos
Bases de Dados Factuais , Plantas/genética , Arabidopsis/enzimologia , Arabidopsis/genética , Genoma de Planta , Internet , Mutação , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/metabolismo , Fosforilação , Plantas/enzimologia , Proteínas Quinases/genética , Proteínas Quinases/metabolismo
15.
Eur J Biochem ; 267(12): 3818-27, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10849001

RESUMO

A calcium- and phospholipid-dependent protein kinase of apparent molecular mass 54 kDa (designated ZmCPKp54) was partially purified from etiolated maize seedlings. Activity of ZmCPKp54 is stimulated by phosphatidylserine and phosphatidylinositol, but is not essentially affected by diolein and phorbol esters. The enzyme cross-reacts with polyclonal antibodies against the calmodulin like-domain of the calcium-dependent protein kinase, but not with antibodies against catalytic or regulatory domains of protein kinase C. ZmCPKp54 is not able to phosphorylate the specific substrates of protein kinase C (MARCKS peptide and protein kinase C substrate peptide derived from pseudosubstrate sequence) and its activity is not inhibited by specific PKC inhibitors (bisindolylmaleimide, protein kinase C pseudosubstrate inhibitory peptide). The substrate specificity and sensitivity to the inhibitors of the maize enzyme resembles calcium-dependent protein kinase. The biochemical and immunological properties indicate that ZmCPKp54 belongs to the calcium-dependent protein kinase family.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Membrana , Fosfolipídeos/metabolismo , Proteínas Quinases/metabolismo , Zea mays/enzimologia , Sequência de Aminoácidos , Cálcio/metabolismo , Reações Cruzadas , Ácido Egtázico/farmacologia , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Isoenzimas , Dados de Sequência Molecular , Peso Molecular , Substrato Quinase C Rico em Alanina Miristoilada , Fragmentos de Peptídeos/metabolismo , Fosfolipídeos/farmacologia , Proteínas Quinases/efeitos dos fármacos , Proteínas Quinases/imunologia , Proteínas Quinases/isolamento & purificação , Proteínas/metabolismo , Sementes/enzimologia , Especificidade por Substrato
16.
Proteins ; 39(4): 343-57, 2000 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10813816

RESUMO

Calmodulin-like domain protein kinases (CDPKs) represent a new class of calcium-dependent protein-phosphorylating enzymes that are not activated by calmodulin or phospholipid compounds. They have been found exclusively in plant and protozoal tissues. CDPKs are typified by four distinct domains: an N-terminal leader sequence, a protein kinase (PK) domain, a calmodulin-like domain (CLD), and a junction domain (JD) between the PK domain and CLD. Structural characterization of the CLD of CDPKalpha from soybean was undertaken based on the amino acid sequence homology of CLD to the structurally well-characterized calmodulin (CaM) family of structures. Tertiary models of apo-CLD, Ca(2+)-CLD complex, and intermolecularly bound Ca(2+)-CLD-JD complexes were obtained via automated and non-automated homology building methods. The resulting structures were compared and validated based on energy differences, phi-psi angle distribution, solvent accessibility, and hydrophobic potential. Circular dichroism, one-dimensional, and two-dimensional nuclear magnetic resonance spectroscopy studies of the CLD and peptides encompassing the JD provide experimental support to the models. The results suggest that there is a possible interaction between the CLD and JD domain similar to that of the CaM/calmodulin-dependent protein kinase II system. At low Ca(2+) levels, the JD may act as an autoinhibitory domain for kinase activity, and during calcium activation an intramolecular CLD-JD complex may form, relieving inhibition of the PK domain. Interactions between the JD and the C terminus of the CLD appear to be particularly important. The outcome of this study supports an intramolecular binding model for calcium activation of CDPK, although not exclusively.


Assuntos
Calmodulina/química , Modelos Moleculares , Proteínas Quinases/química , Sequência de Aminoácidos , Animais , Sítios de Ligação , Cálcio/metabolismo , Dicroísmo Circular , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Glycine max/enzimologia
17.
Plant Physiol ; 122(4): 1035-43, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10759499

RESUMO

Western-blot analysis and protein kinase assays identified two Ca(2+)-dependent protein kinases (CDPKs) of 55 to 60 kD in soluble protein extracts of embryogenic cultures of sandalwood (Santalum album L.). However, these sandalwood CDPKs (swCDPKs) were absent in plantlets regenerated from somatic embryos. swCDPKs exhibited differential expression (monitored at the level of the protein) and activity in different developmental stages. Zygotic embryos, seedlings, and endosperm showed high accumulation of swCDPK, but the enzyme was not detected in the soluble proteins of shoots and flowers. swCDPK exhibited a temporal pattern of expression in endosperm, showing high accumulation and activity in mature fruit and germinating stages; the enzyme was localized strongly in the storage bodies of the endosperm cells. The study also reports for the first time to our knowledge a post-translational inhibition/inactivation of swCDPK in zygotic embryos during seed dormancy and early stages of germination. The temporal expression of swCDPK during somatic/zygotic embryogenesis, seed maturation, and germination suggests involvement of the enzyme in these developmental processes.


Assuntos
Cálcio/metabolismo , Germinação , Plantas/enzimologia , Proteínas Quinases/metabolismo , Sementes , Plantas/embriologia
18.
Trends Plant Sci ; 5(4): 154-9, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10740296

RESUMO

Numerous stimuli can alter the Ca2+concentration in the cytoplasm, a factor common to many physiological responses in plant and animal cells. Calcium-binding proteins decode information contained in the temporal and spatial patterns of these Ca2+ signals and bring about changes in metabolism and gene expression. In addition to calmodulin, a calcium-binding protein found in all eukaryotes, plants contain a large family of calcium-binding regulatory protein kinases. Evidence is accumulating that these protein kinases participate in numerous aspects of plant growth and development.


Assuntos
Sinalização do Cálcio , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Especificidade por Substrato
19.
Neurology ; 54(1): 142-7, 2000 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-10636140

RESUMO

OBJECTIVE: To assess cortical inhibitory and excitatory mechanisms in obsessive-compulsive disorder (OCD). BACKGROUND: Transcranial magnetic stimulation (TMS) studies have found decreased neuronal inhibition and a reduced cortical silent period in the primary motor area in Tourette's syndrome, focal dystonia, and other disorders believed to involve dysfunction of subcortical structures, including the basal ganglia. Dysfunction of the basal ganglia and linked regions also has been implicated in OCD, which has significant clinical and familial overlap with tic disorders. METHODS: We applied the TMS techniques previously used in Tourette's syndrome to a group of 16 OCD patients (seven unmedicated) and 11 age-matched healthy volunteers extensively screened for psychopathology. Measures of motor cortex excitability included resting and active motor threshold, cortical silent period duration, and intracortical inhibition and facilitation using a paired-pulse TMS technique with a subthreshold conditioning stimulus. RESULTS: Similar to recent findings in Tourette's syndrome and focal dystonia, this study reports significantly decreased intracortical inhibition (ICI) relative to the volunteers at interstimulus intervals from 2 to 5 msec. We also found decreased active and resting motor evoked potential threshold in the OCD patients, another indication of increased cortical excitability. Neither abnormality appeared medication related. The decreases in ICI and motor threshold were greatest in OCD patients with comorbid tics, but remained significant in patients without tics. CONCLUSIONS: The data suggest abnormal cortical excitability in obsessive-compulsive disorder. These findings are congruent with the hypothesis that Tourette's syndrome and obsessive-compulsive disorder (OCD) are analogous disorders with overlapping dysfunction in corticobasal circuits. Patients with tic-related OCD may have more abnormal motor cortex excitability than OCD patients without tics.


Assuntos
Córtex Motor/fisiopatologia , Transtorno Obsessivo-Compulsivo/fisiopatologia , Adolescente , Adulto , Limiar Diferencial , Potencial Evocado Motor , Feminino , Humanos , Magnetismo , Masculino , Pessoa de Meia-Idade , Inibição Neural , Transtorno Obsessivo-Compulsivo/complicações , Estimulação Física/métodos , Tiques/complicações
20.
J Telemed Telecare ; 4(2): 84-8, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9744163

RESUMO

The costs of providing oncology services in three different ways were measured. Services were provided to a peripheral hospital by: conventional clinics, in which the oncologist worked at the hospital concerned; outreach clinics, in which an oncologist was flown in periodically from a central hospital; telemedicine clinics, in which the oncologist at the central hospital practised via a video-link. During a one-year study period, 2400 patients were seen in conventional clinics, 81 in outreach clinics and 103 in telemedicine clinics. At these workloads the average costs per patient were $149, $897 and $812, respectively. However, the average costs cannot be compared directly without further information about the shape of the unit cost curves.


Assuntos
Serviço Hospitalar de Oncologia/economia , Telemedicina/economia , Análise Custo-Benefício , Custos de Cuidados de Saúde , Humanos
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