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1.
Neuropsychologia ; 156: 107829, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-33744320

RESUMO

Gender differences in emotion regulation (ER) have been postulated, yet their neural basis remains poorly understood. The goal of this study was to investigate this issue from a functional connectivity (FC) perspective. Utilizing a region of interest (ROI) analysis, we investigated whether men and women (N = 48) differed in their FC pattern while viewing versus regulating negative emotion induced by highly salient pictures, and whether this pattern related to their self-reported negative affect and suppression success. Despite women reporting more negative affect, both genders had comparable suppression success. Moreover, differences emerged between men and women's FC patterns. During the regulation of negative emotion, better suppression in women was associated with stronger FC within a cingulo-opercular network, while men exhibited stronger FC within posterior regions of the ventral attentional network. We conclude that due to their propensity for higher emotional reactivity, women may employ a frontal top-down control network to downregulate negative emotion, while men may redirect attention away from the negative stimulus by using posterior regions of the ventral attention network. The findings may have significant implications for understanding women's vulnerability for developing affective disorders and developing targeted individualized treatment.


Assuntos
Regulação Emocional , Córtex Cerebral , Emoções , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Caracteres Sexuais
2.
J Med Econ ; 20(7): 715-722, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28332417

RESUMO

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a rare kidney disorder impacting ∼1:2,500 individuals among the general US population. Hypertension is a significant predictor of ADPKD progression, and a risk factor for development of cardiovascular disease (CVD), the most common cause for mortality among ADPKD patients. Angiotensin-converting enzymes inhibitors (ACE-I) are widely used as first-line treatment in ADPKD for the management of hypertension. However, their cost-effectiveness relative to other hypertensive medications, such as angiotensin II receptor blockers (ARB), has never been assessed. OBJECTIVE: To determine if ARB are more cost-effective than ACE-Is as first-line treatment in ADPKD. METHODS: A Markov-state decision model was constructed for estimation of cost and outcome benefits in hypertensive ADPKD patients. Transition probabilities were extrapolated from a retrospective cohort study comparing chronic kidney disease (CKD) stage transitions in ADPKD patients. Annual pharmaceutical costs per average daily dose per CKD stage were extracted from a US healthcare claims database. Median total healthcare costs per CKD stage or transplant were extracted from the published literature. The time horizon was set to 30 years, with 1-year duration to cycle shift. A cost-effectiveness analysis was conducted to estimate the incremental cost-effectiveness ratio (ICER) of ACE-I vs ARB per additional year of prevented transplant and/or death. A one-way probabilistic sensitivity analysis was conducted, with 10% variation in probabilities and cost. RESULTS: Total annual healthcare costs accrued after 30 years among ADPKD patients taking ACE-Is was estimated to be $3,505,028.41, compared to ARB at $3,644,327.65. Life expectancy was increased by 1.39 years among patients taking ACE-I. Approximate 10-year survival in patients taking ACE-Is was 47% compared to ARB at 34%. CONCLUSIONS: ACE-I dominated ARB and displayed greater cost-effectiveness due to lower cost and increased capacity to prolong years of life without transplant or death among hypertensive ADPKD patients. This model strengthens the value of ACE-I over ARB as first-line treatment for hypertension management in ADPKD patients.


Assuntos
Antagonistas de Receptores de Angiotensina/economia , Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/economia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Hipertensão/tratamento farmacológico , Rim Policístico Autossômico Dominante/tratamento farmacológico , Análise Custo-Benefício , Progressão da Doença , Honorários Farmacêuticos/estatística & dados numéricos , Taxa de Filtração Glomerular , Humanos , Hipertensão/complicações , Revisão da Utilização de Seguros/estatística & dados numéricos , Cadeias de Markov , Modelos Econômicos , Rim Policístico Autossômico Dominante/complicações , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Estados Unidos
3.
Br J Cancer ; 111(2): 413-20, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24983368

RESUMO

BACKGROUND: The external quality assurance (EQA) process aims at establishing laboratory performance levels. Leading European groups in the fields of EQA, Pathology, and Medical and Thoracic Oncology collaborated in a pilot EQA scheme for somatic epidermal growth factor receptor (EGFR) gene mutational analysis in non-small-cell lung cancer (NSCLC). METHODS: EQA samples generated from cell lines mimicking clinical samples were provided to participating laboratories, each with a mock clinical case. Participating laboratories performed the analysis using their usual method(s). Anonymous results were assessed and made available to all participants. Two subsequent EQA rounds followed the pilot scheme. RESULTS: One hundred and seventeen labs from 30 countries registered and 91 returned results. Sanger sequencing and a commercial kit were the main methodologies used. The standard of genotyping was suboptimal, with a significant number of genotyping errors made. Only 72 out of 91 (72%) participants passed the EQA. False-negative and -positive results were the main sources of error. The quality of reports submitted was acceptable; most were clear, concise and easy to read. However, some participants reported the genotyping result in the absence of any interpretation and many obscured the interpretation required for clinical care. CONCLUSIONS: Even in clinical laboratories, the technical performance of genotyping in EGFR mutation testing for NSCLC can be improved, evident from a high level of diagnostic errors. Robust EQA can contribute to global optimisation of EGFR testing for NSCLC patients.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Receptores ErbB/genética , Neoplasias Pulmonares/genética , Mutação , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Genótipo , Humanos , Neoplasias Pulmonares/enzimologia , Controle de Qualidade
4.
J Vet Intern Med ; 27(4): 791-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23663198

RESUMO

BACKGROUND: Food and Drug Administration Center for Veterinary Medicine (FDA/CVM) cited concern regarding failure of heartworm prophylaxis. The positive and negative predictive value of the heartworm antigen test is an estimate of the probability of adult heartworm infection. HYPOTHESIS/OBJECTIVES: Assess the sensitivity, specificity, and predictive value of heartworm antigen tests. Explore the role of heartworm test accuracy and treatment with immiticide to generate reports of suspected failure of heartworm prophylaxis. METHODS: Literature searches for published information on the accuracy of heartworm antigen tests and efficacy of immiticide for treatment of the adult heartworm. RESULTS: Weighted averages for heartworm antigen test sensitivity and specificity were 78.2 and 97.3%, respectively. Efficacy of immiticide by 2-injection or alternate dose protocols were 88.3 and 89.1%, respectively. Depending on prevalence, the positive predictive value of the heartworm antigen test ranged from 15 to 54% and negative predictive value from 99 to 99.9%. For a hospital testing 1,000 dogs per year, false-positive test results may vary from 24 to 27 dogs. If these dogs were on heartworm preventive, they may undergo treatment and be classified as prophylaxis failures. Ten percent of dogs who were treated and continued or placed on prophylaxis at the time of treatment may have adult heartworms when tested 1 year later and be presumed to represent failure of prophylaxis. CONCLUSIONS: When interpreting heartworm antigen test results, clinical signs, history, and regional prevalence of heartworm disease should be considered in estimating the predictive value of the test result. Limitations of test and treatment should be discussed with clients as part of the decision-making process.


Assuntos
Anti-Helmínticos/uso terapêutico , Antígenos de Helmintos/sangue , Dirofilariose/prevenção & controle , Doenças do Cão/prevenção & controle , Animais , Anti-Helmínticos/administração & dosagem , Cães , Reações Falso-Positivas , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Falha de Tratamento
5.
Eur J Neurol ; 18(11): 1329-35, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21985026

RESUMO

BACKGROUND AND PURPOSE: These studies tested the hypothesis that hypoxia inducible factor-1α (HIF-1α) pathway activation occurs in substantia nigra neurons and brain microvasculature in patients with restless legs syndrome. METHODS: Immunohistochemical analyses of substantia nigra tissue from six RLS and six control subjects were analyzed for HIF-1α, neuronal nitric oxide synthase (nNOS) and nitrotyrosine immunoreactivity. Microvessel lysates were obtained from cortex tissue from four RLS and four control subjects and the lysates were quantified for HIF-2α and vascular endothelial growth factor (VEGF) expression using immunoblot analyses. HIF-1α activation of peripheral blood monocyte cells (PBMCs) (14 RLS and 9 control) was determined through immunoblot analysis of PBMC lysates for EPO. RESULTS: HIF-1α immunoreactivity in substantia nigra neurons was significantly increased in five of six RLS patients as compared with controls. In addition, nNOS and nitrotyrosine expression are up-regulated in the substantia nigra of four of six RLS patients as compared with controls. HIF-2α and VEGF expression are significantly up-regulated in the microvasculature lysates from four RLS cortical brain tissue as compared with controls. Erythropoietin levels are significantly increased in RLS PBMCs. CONCLUSIONS: These results demonstrate that the hypoxia pathway is activated in multiple cell types in individuals with RLS. Increased nNOS and nitrotyrosine suggests that nitric oxide is involved in the activation. Activation of the hypoxia pathway can result from or contribute to cellular iron deficiency. These observations suggest a novel direction to explore in RLS that is tied to the iron deficiency model but better explains the findings in postmortem studies.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Subunidade alfa do Fator 1 Induzível por Hipóxia/biossíntese , Síndrome das Pernas Inquietas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiopatologia , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Masculino , Pessoa de Meia-Idade , Vias Neurais/fisiologia , Síndrome das Pernas Inquietas/fisiopatologia , Substância Negra/metabolismo , Substância Negra/fisiopatologia , Regulação para Cima/fisiologia , Fator A de Crescimento do Endotélio Vascular/biossíntese , Fator A de Crescimento do Endotélio Vascular/fisiologia
6.
J Inherit Metab Dis ; 31(6): 697-702, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19015950

RESUMO

DNA sequence analyses have become a major component in the diagnostic work-up of patients; however, limited consideration appears to be given to the possibility that reported results may in fact be wrong. Over the last four years we have carried out an External Quality Assessment scheme for mutation analysis in phenylketonuria. Each year, three DNA samples with previously characterized genotypes were mailed to participating laboratories. Indications for testing were either confirmation of diagnosis and prediction of disease severity, or carrier analysis. Each year there were several laboratories that failed to identify mutations because of methodological limitations. Of the participating laboratories that used comprehensive mutation detection methods, each year there was at least one that missed at least one mutation. Indeed, in the 2007 scheme almost 8% of reports from laboratories that used comprehensive mutation detection methods such as sequencing of all exons of the PAH gene contained incorrect genotypes. There were also serious deficiencies in the interpretation of genotype data: in the 2007 scheme, 6 out of 10 laboratories that obtained full genotyping marks for interpretation incurred a reduction of marks because information on the expected phenotype was missing or wrong. Several laboratories failed to appreciate the clinical relevance of a mutation associated with mild hyperphenylalaninaemia, which does not require treatment, and some discussed the option of prenatal diagnosis in the respective case. In conclusion, mutation analyses may be prone to errors and this demands careful interpretation of results in relation to clinical and biochemical findings.


Assuntos
Química Clínica/métodos , Fenilcetonúrias/diagnóstico , Fenilcetonúrias/genética , Química Clínica/economia , Análise Mutacional de DNA , Éxons , Genótipo , Humanos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Mutação , Fenilalanina Hidroxilase/metabolismo , Garantia da Qualidade dos Cuidados de Saúde , Controle de Qualidade , Reprodutibilidade dos Testes
7.
Arch Womens Ment Health ; 10(5): 221-4, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17701271

RESUMO

Postpartum depression (PPD) is a frequent complication of childbirth, but many women refuse pharmacological treatment. Little data exists on bright light therapy for PPD. Fifteen outpatient women with PPD were randomly assigned to bright light (10,000 lux, n = 10) or dim red light (600 lux, n = 5) and completed a 6-week trial and weekly assessments using self-report depression scales and clinician ratings of symptom course. Both groups showed significant improvement over time on all measures, with no significant difference between conditions.


Assuntos
Ritmo Circadiano , Depressão Pós-Parto/terapia , Transtorno Depressivo Maior/terapia , Fototerapia , Adulto , Depressão Pós-Parto/diagnóstico , Depressão Pós-Parto/psicologia , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/psicologia , Feminino , Seguimentos , Humanos , Inventário de Personalidade , Projetos Piloto , Estudos Prospectivos
8.
J Hum Nutr Diet ; 17(6): 523-7, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15546429

RESUMO

OBJECTIVES: To compare the food group variety and nutritional adequacy of the diet between toddlers with cystic fibrosis (CF) and age-matched controls. Subjects A clinical sample of 22 toddlers with CF (mean age=21.3 +/- 7.2 months) matched to a community sample of 22 healthy peers. MAIN OUTCOME MEASURES: The variety index for toddlers (VIT) and the mean adequacy ratio (MAR). RESULTS: Fruit group scores were highest for children with CF (0.95 +/- 0.13; possible range 0.00-1.00), and dairy group scores were highest for controls (0.90 +/- 0.18). All children earned the lowest scores for vegetables (CF: 0.15 +/- 0.12; controls: 0.26 +/- 0.22). No significant differences were found when comparing VIT and MAR scores by sample (P >0.05). A moderate positive relationship was found between total VIT scores and MAR scores for all children (r=0.38, P <0.05). Toddlers with CF did not achieve the 120-150% of Recommended Dietary Allowance (RDA) for energy. CONCLUSIONS: Toddlers with CF are consuming diets that are varied and nutritionally adequate for a healthy child. To optimize nutritional status and growth, current recommendations for toddlers with CF to eat a well-balanced diet and to exceed daily RDA for energy requirements remain key dietary issues.


Assuntos
Fibrose Cística , Dieta/normas , Ingestão de Energia , Alimentos/classificação , Estudos de Casos e Controles , Fibrose Cística/fisiopatologia , Laticínios , Registros de Dieta , Inquéritos sobre Dietas , Comportamento Alimentar , Feminino , Frutas , Humanos , Lactente , Masculino , Política Nutricional , Necessidades Nutricionais , Verduras
9.
Neurology ; 62(9): 1563-7, 2004 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-15136682

RESUMO

BACKGROUND: Restless legs syndrome (RLS) is a sensory-movement disorder affecting 5 to 10% of the population. Its etiology is unknown, but MRI analyses and immunohistochemical studies on autopsy tissue suggest the substantia nigra (SN) of patients with RLS has subnormal amounts of iron. METHODS: Neuromelanin cells from the SN of four RLS and four control brains were isolated by laser capture microdissection, and a profile of iron-management protein expression was obtained by immunoblot analysis. Binding assays for iron regulatory protein activity were performed on cell homogenates. RESULTS: Ferritin, divalent metal transporter 1, ferroportin, and transferrin receptor (TfR) were decreased in RLS neuromelanin cells compared with control. Transferrin was increased in RLS neuromelanin cells. This protein profile in RLS neuromelanin cells is consistent with iron deficiency with the exception that TfR expression was decreased rather than increased. The concentration and activity of the iron regulatory proteins (IRP1 and IRP2) were analyzed to determine whether there was a functional deficit in the post-transcriptional regulatory mechanism for TfR expression. Total IRP activity, IRP1 activity, and IRP1 protein levels were decreased in RLS, but total IRP2 protein levels were not decreased in RLS. CONCLUSION: Restless legs syndrome may result from a defect in iron regulatory protein 1 in neuromelanin cells that promotes destabilization of the transferrin receptor mRNA, leading to cellular iron deficiency.


Assuntos
Melaninas/metabolismo , Receptores da Transferrina/metabolismo , Síndrome das Pernas Inquietas/metabolismo , Idoso , Idoso de 80 Anos ou mais , Anemia Ferropriva , Feminino , Expressão Gênica , Humanos , Hibridização In Situ , Ferro/metabolismo , Proteínas Reguladoras de Ferro/metabolismo , Masculino , Microdissecção , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , RNA Mensageiro/metabolismo , Substância Negra/citologia , Substância Negra/metabolismo , Transferrina/metabolismo
10.
Cephalalgia ; 24(2): 120-7, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14728707

RESUMO

The aim of this study was to measure quality of life (QOL) across a broad age range of paediatric migraine patients. Children and adolescents (n=686) with migraine completed the Pediatric Quality of Life Inventory, version 4.0 (PedsQL 4.0) and a standardized headache assessment at an initial clinic visit. The sample size for each PedsQL age group was: age 2-4=21, age 5-7=86, age 8-12=298, and age 13-18=281. Mean total score was 72.7 +/- 14.8, significantly less than healthy norms (P<0.01). Teens reported lower School Functioning than older and young children (P<0.05) and young children reported lower Social Functioning than older children and teens (P<0.001). A moderate relation was found between self and parent report. Age-related effects on QOL have implications for the evaluation and management of migraine in paediatric practice. The self and parent report forms of the PedsQL can be used in a practice setting.


Assuntos
Transtornos de Enxaqueca/psicologia , Qualidade de Vida , Inquéritos e Questionários , Adolescente , Fatores Etários , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pais
11.
J Parasitol ; 87(5): 1174-6, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11695389

RESUMO

Adult nematode parasites were recovered from the heart blood of a deceased island fox (Urocyon littoralis) submitted for necropsy to determine the cause of death. Examination of the recovered nematodes supported the generic diagnosis of Angiocaulus, a parasite in Angiostrongylidae found in domestic and wild canids and mustelids. Specific diagnosis of the worms from the island fox as Angiocaulus gubernaculatus is based on the morphology of the dorsal ray in the copulatory bursa of the male worm and its comparison with published descriptions of Angiocaulus raillieti and A. gubernaculatus. Although A. gubernaculatus has been typically associated with mustelid hosts, its occurrence in the island fox indicates that the host distribution for the parasite may not be as restricted as previously believed.


Assuntos
Angiostrongylus/anatomia & histologia , Raposas/parasitologia , Infecções por Strongylida/veterinária , Angiostrongylus/isolamento & purificação , Animais , California , Feminino , Raposas/sangue , Geografia , Masculino , Infecções por Strongylida/sangue , Infecções por Strongylida/parasitologia
13.
Adv Exp Med Biol ; 501: 35-45, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11787701

RESUMO

While reasons for gross variations in milk composition of the various mammalian species are well established, we will be revealing minor, subtle, yet highly important differences for years to come. One of the distinctive differences of human milk concerns its mucins, MUC1 and MUC-X. These are high molecular mass glycoproteins that occur on the apical surface of the lactating cell and are transferred to the milk fat globule upon its secretion from the cell. Among mammals, it seems that the human has developed the largest, most extended versions of these mucin molecules. Evidence is accumulating that this greater size benefits the human in terms of protection against infections and injurious environmental agents.


Assuntos
Antígenos Glicosídicos Associados a Tumores , Mama/química , Glicoproteínas de Membrana , Leite Humano/química , Mucina-1 , Mucinas , Animais , Antígenos Glicosídicos Associados a Tumores/análise , Antígenos Glicosídicos Associados a Tumores/química , Antígenos Glicosídicos Associados a Tumores/metabolismo , Epitélio/química , Feminino , Humanos , Recém-Nascido , Glicoproteínas de Membrana/análise , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/metabolismo , Estrutura Molecular , Mucina-1/análise , Mucina-1/química , Mucina-1/genética , Mucinas/análise , Mucinas/química , Mucinas/metabolismo , Polimorfismo Genético , Especificidade da Espécie
15.
Shock ; 14(2): 234-42, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10947172

RESUMO

To test the effects of prostaglandin E1 on 2.5 h of ischemia followed by 2 h of reperfusion, continuous nitric oxide measurements (electrochemical) were correlated with intermittent assays of superoxide and peroxynitrite levels (chemiluminescence) and ischemia/reperfusion injury in rabbit adductor magnus muscle. Administering prostaglandin E1 (1 microg/kg) before or during ischemia/reperfusion caused normalization of the release of nitric oxide, superoxide, and peroxynitrite to slightly above preischemic levels. This pattern was dramatically different from that observed during ischemia/reperfusion alone, where nitric oxide concentration increased three times above its basal level. Normalization of constitutive nitric oxide synthase activity in the presence of prostaglandin E1 was associated with a significant reduction of superoxide and peroxynitrite production and subsequent reduction of ischemia/reperfusion injury. At 2 h of reperfusion, vasoconstriction associated with ischemia/reperfusion injury was eliminated, and edema was significantly mollified but still apparent. Prostaglandin E1 treatment does not directly inhibit constitutive nitric oxide synthase, like the inhibitor N(omega)-monomethyl-L-arginine. Some phenomenon associated with ischemia turns on endothelial constitutive nitric oxide synthase to start transforming L-arginine and oxygen into nitric oxide, but prostaglandin E1 seems to inhibit this phenomenon. Thus, essential local L-arginine pools are not depleted, and normal basal levels of essential nitric oxide are maintained, whereas cytotoxic superoxide and peroxynitrite production by L-arginine-deficient constitutive nitric oxide synthase is prevented.


Assuntos
Alprostadil/uso terapêutico , Membro Posterior/irrigação sanguínea , Isquemia/tratamento farmacológico , Óxido Nítrico/biossíntese , Traumatismo por Reperfusão/prevenção & controle , Superóxidos/metabolismo , Acetilcolina/farmacologia , Alprostadil/farmacologia , Animais , Avaliação Pré-Clínica de Medicamentos , Masculino , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/metabolismo , Nitratos/metabolismo , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo III , Coelhos , Traumatismo por Reperfusão/tratamento farmacológico , Vasoconstrição/efeitos dos fármacos
16.
J Parasitol ; 86(4): 846-9, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10958469

RESUMO

Archeological deposits from the 19th century company town of Fayette, Michigan were analyzed for evidence of endoparasitic infection in the human population residing in the town between 1867 and 1891. Three privies were associated with upper-income and middle-income neighborhoods; 2 household refuse disposal areas were found in a predominately lower-income immigrant working class neighborhood. Sediment samples from 2 privies associated with dwellings in the middle-income neighborhood were positive for eggs of the human whipworm Trichuris trichiura. The parasite was probably also present among residents of the lower income neighborhood, but the shallow nature of the refuse deposits in that locality precluded preservation of the eggs. Contemporary epidemiologic studies of helminth infections support the belief that T. trichiura may have been a common parasite of 19th century school-age children given the natural inclination of young children to defecate indiscriminately, play freely in the dirt, and eat without washing their hands.


Assuntos
Tricuríase/história , Animais , Fezes/parasitologia , História do Século XIX , Humanos , Michigan , Fatores Socioeconômicos , Banheiros/história , Trichuris/isolamento & purificação
17.
Biochemistry ; 39(25): 7595-604, 2000 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-10858310

RESUMO

The side chain of the antifungal polyketide ansatrienin A produced by Streptomyces collinus contains a cyclohexanecarboxylic acid (CHC) derived moiety. This CHC in the coenzyme A activated form (CHC-CoA) is derived from shikimic acid via a pathway in which the penultimate step is the isomerization of 2-cyclohexenylcarbonyl-CoA to 1-cyclohexenylcarbonyl-CoA. We have purified a 28 kDa 2-cyclohexenylcarbonyl-CoA isomerase (ChcB) from S. collinus and cloned and sequenced the corresponding chcB gene. The predicted amino acid sequence of ChcB showed moderate sequence identity to members of the hydratase/isomerase superfamily of enzymes. The recombinant ChcB was overexpressed in Escherichia coli and purified to homogeneity using metal chelate chromatography. Kinetic analysis demonstrated that recombinant ChcB had wide substrate specificity and could catalyze a double bond isomerization using 2-cyclohexenylcarbonyl-CoA (K(m) 116 +/- 68 microM, k(cat)( )()3.7 +/- 1.0 min(-)(1)), trans-3-hexenyl-CoA (K(m) 39 +/- 10 microM, k(cat)( )()12.8 +/- 1 min(-)(1)), and vinylacetyl-CoA (K(m) 156 +/- 34 microM, k(cat)( )()29 +/- 3 min(-)(1)) as substrates. ChcB activity in cell extracts of S. collinus SP1, an insertionally disrupted chcB mutant, was shown to decrease by more than 99% (as compared to the wild-type strain) using all three of these substrates. The S. collinus SP1 strain, unlike the wild-type strain, could not produce omega-cyclohexyl fatty acids but was still able to grow efficiently on methyl oleate as a sole carbon source. These observations demonstrate that the S. collinus ChcB is required for catalyzing the isomerization of 2-cyclohexenylcarbonyl-CoA to 1-cyclohexenylcarbonyl-CoA during CHC-CoA biosynthesis but not for degradation of unsaturated fatty acids. The chcB gene does not appear to be associated with the ansatrienin biosynthetic gene cluster, which has previously been shown to contain at least one gene known to be essential for CHC-CoA biosynthesis. This finding represents a notable exception to the general rule regarding the clustering of polyketide biosynthetic pathway genes.


Assuntos
Antibacterianos/metabolismo , Isomerases de Ligação Dupla Carbono-Carbono/metabolismo , Ácidos Cicloexanocarboxílicos/química , Sequência de Aminoácidos , Antibacterianos/química , Sequência de Bases , Isomerases de Ligação Dupla Carbono-Carbono/química , Isomerases de Ligação Dupla Carbono-Carbono/genética , Isomerases de Ligação Dupla Carbono-Carbono/isolamento & purificação , Clonagem Molecular , Sondas de DNA , Dados de Sequência Molecular , Fenótipo , Quinonas/química , Quinonas/metabolismo , Homologia de Sequência de Aminoácidos , Streptomyces/enzimologia
19.
J Zoo Wildl Med ; 31(3): 322-8, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11237138

RESUMO

Ninety-eight fecal samples were collected from 74 free-living mountain gorillas (Gorilla gorilla beringei) from the Parc National des Volcans, Rwanda, between July 1995 and January 1997 and examined for parasites by Sheather's sugar and zinc sulfate flotation methods, trichrome staining, and larval cultures. All samples contained at least one parasite. Seventeen endoparasites were identified, including eight protozoa, seven nematodes, one cestode, and one trematode. Two species of arthropod mite were also recovered from the fecal samples. Parasites observed on fecal examinations included strongyle/trichostrongyle-type eggs (72/74) (representing Oesphagostomum sp., Trichostrongylus sp., Hyostrongylus spp., and possibly Murshidia sp.), Strongyloides sp. (1/74), Trichuris trichiura (2/74), Probstmayria sp. (7/74), Anoplocephala sp. (63/74), Entamoeba hartmanni cysts and trophozoites (19/70), Endolimax nana cysts (31/70), Iodamoeba buetschlii cysts (11/70), Endolimax nana or Iodamoeba buetschlii trophozoites (63/70). Entamoeba coli cysts and trophozoites (14/70), Entamoeba histolytica trophozoite (1/70), Chilomastix sp. cysts and trophozoites (31/70), and Giardia sp. cysts (2/70). In addition, one ascarid and one trematode egg were seen. There were no significant differences in the prevalence of parasites between males and females and between age groups: however, infants and juveniles appeared to have a lower prevalence of Anoplocephala gorillae, and the silverbacked males appeared to have a higher prevalence of Probstmayria sp. Parasite prevalence was consistent among the five social groups studied except Susa group had a significantly lower prevalence of Anoplocephala gorillae. Trichuris trichiura, Strongyloides sp., Chilomastix sp., and Endolimax nana were identified for the first time in this population, and it is possible that these parasites were of human origin. Although there were no obvious clinical effects due to the presence of these parasites, six parasites identified (Trichuris trichiura, Strongyloides sp., Oesphagostomum sp., Trichostrongylus sp., Entamoeba histolytica, and Giardia sp.) could potentially be pathogenic. Some of the parasite products and cultured larvae could not be speciated.


Assuntos
Sistema Digestório/parasitologia , Gorilla gorilla/parasitologia , Animais , Entamoeba/isolamento & purificação , Fezes/parasitologia , Feminino , Giardia/isolamento & purificação , Masculino , Ácaros , Ruanda , Strongyloides/isolamento & purificação , Trematódeos/isolamento & purificação , Trichuris/isolamento & purificação
20.
Vet Surg ; 28(5): 348-54, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10493639

RESUMO

OBJECTIVE: To determine if once-daily colonic irrigation results in fecal continence for a 24-hour period in dogs with colostomies and if colonic volume increased in response to the irrigation. STUDY DESIGN: A prospective controlled experimental study. ANIMALS: Four intact male and one intact female mixed breed dogs. MATERIALS: All dogs received left end-on paralumbar colostomies. Four dogs received once-daily colonic irrigation for 8 weeks, whereas the control dog did not. Daily fecal weights were recorded for the length of the study in all dogs. Barium enema studies and volumetric studies were used to determine colonic volumes. RESULTS: Daily fecal weights were significantly decreased in treatment dogs compared with the control dog. Colonic volume increased in irrigated dogs in response to daily irrigation over the 8 week period of the study. CONCLUSIONS: Colonic irrigation resulted in significantly decreased fecal production over a 24-hour period. Therefore management of dogs with colostomies would be more practical and cost effective. It did not result in complete fecal continence in this study. Further clinical studies are indicated to determine if longer periods of irrigation would result in complete continence.


Assuntos
Doenças do Colo/veterinária , Colostomia/veterinária , Doenças do Cão/prevenção & controle , Incontinência Fecal/veterinária , Animais , Doenças do Colo/cirurgia , Doenças do Cão/cirurgia , Cães , Incontinência Fecal/prevenção & controle , Feminino , Masculino , Irrigação Terapêutica/veterinária
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