Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 226
Filtrar
1.
Aust Vet J ; 101(3): 99-105, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36482150

RESUMO

Malignant mesothelioma (MM) is uncommon in cats and dogs and can be challenging to diagnose. Adequate tissue sampling is required for superior diagnostic accuracy. Protoporphyrin IX, a metabolite of 5-aminolaevulinic acid (5-ALA), is a photosensitiser for photodynamic diagnosis (PDD). To the best of our knowledge, no study has reported the use of 5-ALA-PDD to detect MM in veterinary medicine. The present study describes the use of 5-ALA-PDD for MM diagnosis in a cat and dog, as well as the effectiveness of intracavitary chemotherapy. We evaluated the use of PDD with 5-ALA hydrochloride (5-ALA-PDD) in two cases of MM. A 12-year-old cat presented with a 1-month history of respiratory distress, and a 9-year-old dog presented with a 3-month history of mild abdominal distention. We endoscopically biopsied lesions in both the cases using 5-ALA-PDD. Histopathological examination revealed mesothelioma, and immunohistochemical staining was positive for calretinin. Both patients were treated with carboplatin. The cat died of respiratory failure. Although, the dog's condition improved 21 days after the first chemotherapeutic drug administration, the dog died on day 684 owing to cardiac-related issues. 5-ALA-PDD is thus, safe and feasible for the diagnosis of MM in veterinary medicine.


Assuntos
Doenças do Gato , Doenças do Cão , Mesotelioma Maligno , Gatos , Cães , Animais , Mesotelioma Maligno/veterinária , Ácido Aminolevulínico , Fármacos Fotossensibilizantes , Biópsia/veterinária
2.
J Small Anim Pract ; 61(8): 516-519, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-30351464

RESUMO

Photodynamic detection using 5-aminolevulinic acid has been used to identify the surgical margins during resection of human primary brain tumours. Although there are some reports on its use in malignant tumours in veterinary medicine, it has never been used for primary brain tumours. Here we describe a canine glioblastoma that was detected at autopsy with protoporphyrin IX fluorescence induced by orally administered 5-aminolevulinic acid. The fluorescence was strongest towards the centre of the lesion and was absent in normal brain tissue. Moreover, the fluorescence findings were consistent with MRI and histopathological findings. Our findings suggest that photodynamic detection using 5-aminolevulinic acid might be useful for intraoperative fluorescence-guided resection of malignant gliomas in dogs.


Assuntos
Neoplasias Encefálicas/veterinária , Doenças do Cão , Glioblastoma/veterinária , Ácido Aminolevulínico , Animais , Encéfalo , Cães , Fluorescência , Humanos
4.
Pestic Biochem Physiol ; 156: 44-55, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31027580

RESUMO

The use of 1,1'-(2,2,2-Trichloro-1,1-ethanediyl)bis(4-chlorobenzene) (DDT) as a pesticide for the control of insects vectors responsible for the spread of many life threatening diseases was officially banned in 1972 by the United States Environmental Protection Agency (USEPA). It was banned throughout the world, in most developed countries, because of the toxic effects it causes in wildlife, including birds and fish. However, DDT is still used in approximately 43 African countries, including South Africa, to control the spread of malaria. The lipophilic nature of DDT and therefore its persistence in the environment makes it extremely important for laboratory based studies to be conducted in an effort to evaluate the accumulation potential and possible physiological effects of DDT in aquatic organisms under controlled conditions. The aim of this study was to establish baseline bioaccumulation concentrations within Synodontis zambezensis following an acute exposure to 4,4'-DDT. The three metabolites analysed were 4,4'-DDE, 4,4'-DDD and 4,4'-DDT. None of the 2,4'-isomers were analysed in this study since the acute exposure used a solution of 98.7% pure 4,4'-DDT (Sigma-Aldrich PESTANAL®, Analytical Standard, CAS-No 50-29-3, Batch number SZBE057XV) and not a mixture of 4,4'-DDT and 2,4'-DDT as found in technical grade DDT. Soxhlet extraction of tissue samples and liquid/liquid extraction of water samples followed by analysis through Gas-chromatography mass-spectrophotometry was completed. Mean 4,4'-DDE, 4,4'-DDD and 4,4'-DDT concentrations ranged from 15.34 ng/g to 45.34 ng/g, 28.16 ng/g to 63.25 ng/g and 28.64 ng/g to 96.21 ng/g respectively. All of the accumulated concentrations fell within environmentally relevant concentrations with no input through the food web. The accumulated concentrations of 4,4'-DDT and its three metabolites resulted in oxidative stress responses within the gills and the liver tissue of S. zambezensis. Significant differences (p ≤ .05) were observed between malondialdehyde (MDA) and reduced glutathione (GSH) within the liver and in superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) in the gills.


Assuntos
DDT/toxicidade , Peixes/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Animais , Biomarcadores/metabolismo , Monitoramento Ambiental
5.
Chemosphere ; 225: 647-658, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30901658

RESUMO

DDT remains in use for malaria control in South Africa. We quantified DDTs in aquatic bird eggs from the highly biodiverse northern KwaZulu-Natal, a province of South Africa where DDT has been used for more than 80 years for malaria control. Pelican eggs had the highest ΣDDT concentration (7200 ng/g lipid mass; lm), Little Egret eggs had 6900 ΣDDT lm, African Openbill eggs had 3400 ng/g lm ΣDDT, and White-breasted Cormorant had 2400 ng/g lm. All species had non-significantly different mean concentrations of o,p'-DDT, p,p'-DDT, and ΣDDT, but with significant differences for p,p-DDE, o,p'-DDD, p,p'-DDD, %DDT, %DDD, and %lipid. The thinnest pelican eggshell (0.40 mm) had a ΣDDT concentration of 3300 ng/g lm.; the thickest shell (0.96 mm) had the lowest ΣDDT concentration at 29 ng/g lm; a 58% difference. Linear regressions of concentrations with shell thickness for the pelican eggs were significant for p,p'-DDE and p,p'-DDD, indicating risk of reproductive impairment. Compositional profiles indicate different food webs for the different species. DDT concentrations were lower than from another DDT-sprayed locality in South Africa, possible linked to differences in hydrology and rainfall. We conclude that significant ecotoxic threats associated with DDT remain in this area, and possibly threatens birds from less polluted areas. Our findings suggest continued negative human health and environmental impacts from DDT. There is an urgency to move away from DDT as quickly as possible; alternatively, to implement practices that prevent emissions of DDT to the environment while protecting human life.


Assuntos
Aves/embriologia , DDT/análise , Casca de Ovo/química , Ovos/análise , Animais , DDT/farmacologia , Diclorodifenil Dicloroetileno/análise , Poluentes Ambientais/análise , Humanos , Malária/prevenção & controle , África do Sul
6.
Environ Toxicol Chem ; 38(1): 106-114, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30284322

RESUMO

Physical systems, such as currents and winds, have traditionally been considered responsible for transporting contaminants. Although evidence is mounting that animals play a role in this process through their movements, we still know little about how such contaminant biotransport occurs and the extent of effects at deposition sites. In the present study, we address this question by studying how rhinoceros auklets (Cerorhinca monocerata), a seabird that occurs in immense colonies (∼300 000 pairs at our study site, Teuri Island), affect contaminant levels at their colony and at nearby sites. More specifically, we hypothesize that contaminants are transported and deposited by seabirds at their colony and that these contaminants are passed on locally to the terrestrial ecosystem. To test this hypothesis, we analyzed the concentration of 9 heavy metal and metalloids, as well as δ13 C and δ15 N stable isotopes, in bird tissues, plants, and soil, both within and outside of the colony. The results show that rhinoceros auklets transport marine-derived mercury (Hg), possibly from their wintering location, and deposit Hg via their feces at their breeding site, thereby contaminating plants and soils within the breeding colony. The present study confirms not only that animals can transport contaminants from marine to terrestrial ecosystems, potentially over unexpectedly long distances, but also that bird tissues contribute locally to plant contamination. Environ Toxicol Chem 2019;38:106-114. © 2018 SETAC.


Assuntos
Charadriiformes/metabolismo , Ecossistema , Metais/metabolismo , Água do Mar , Oligoelementos/metabolismo , Animais , Transporte Biológico , Monitoramento Ambiental , Eritrócitos/metabolismo , Fezes/química , Geografia , Ilhas , Isótopos de Mercúrio , Metaloides/metabolismo , Raízes de Plantas/metabolismo , Plantas/metabolismo , Análise de Componente Principal , Solo/química
7.
Bull Environ Contam Toxicol ; 100(5): 672-676, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29546500

RESUMO

Many countries with incidence of malaria, including those surrounding Maputo Bay, use dichloro-diphenyl-trichloroethane (DDT) to reduce mosquitoes. This study is the first to estimate the human health risk associated with consumption of marine fish from Maputo Bay contaminated with DDTs. The median for ∑DDTs was 3.8 ng/g ww (maximum 280.9 ng/g ww). The overall hazard ratio for samples was 1.5 at the 75th percentile concentration and 28.2 at the 95th percentile. These calculations show increased potential cancer risks due to contamination by DDTs, data which will help policy makers perform a risk-benefit analysis of DDT use in malaria control programs in the region.


Assuntos
DDT/metabolismo , Exposição Dietética/estatística & dados numéricos , Monitoramento Ambiental , Peixes/metabolismo , Alimentos Marinhos/estatística & dados numéricos , Poluentes Químicos da Água/metabolismo , Animais , Baías/química , Compostos de Bifenilo , DDT/análise , Humanos , Moçambique , Risco , Medição de Risco , Tricloroetanos/análise , Tricloroetanos/metabolismo , Poluentes Químicos da Água/análise
8.
Poult Sci ; 97(5): 1722-1729, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29462429

RESUMO

Avian species have a unique renal structure and abundant blood flow into the kidneys. Although many birds die due to nephrotoxicity caused by chemicals, there are no early biomarkers for renal lesions. Uric acid level in blood, which is generally used as a renal biomarker, is altered when the kidney function is damaged by over 70%. Therefore, early biomarkers for kidney injury in birds are needed. In humans, glycomics has been at the forefront of biological and medical sciences, and glycans are used as biomarkers of diseases, such as carcinoma. In this study, a glycomics approach was used to screen for renal biomarkers in chicken. First, a chicken model of kidney damage was generated by injection of diclofenac or cisplatin, which cause acute interstitial nephritis (AIN) and acute tubular necrosis (ATN), respectively. The nephrotoxicity levels were determined by a blood chemical test and histopathological analysis. The plasma N-glycans were then analyzed to discover renal biomarkers in birds. Levels of 14 glycans increased between pre- and post administration in kidney-damaged chickens in the diclofenac group, and some of these glycans had the same presumptive composition as those in human renal carcinoma patients. Glycan levels did not change remarkably in the cisplatin group. It is possible that there are changes in glycan expression due to AIN, but they do not reflect ATN. Although further research is needed in other species of birds, glycans are potentially useful biomarkers for AIN in avian species.


Assuntos
Galinhas , Glicômica/métodos , Nefropatias/veterinária , Rim/metabolismo , Doenças das Aves Domésticas/diagnóstico , Animais , Biomarcadores/análise , Cisplatino , Diclofenaco , Nefropatias/diagnóstico , Masculino
9.
Artigo em Inglês | MEDLINE | ID: mdl-28737099

RESUMO

Organochlorine pesticides such as dichlorodiphenyltrichloroethane (DDT) have been used in agriculture and for disease control purposes over many decades. Reports suggest that DDT exposure may result in a number of adverse effects in humans. In the KwaZulu-Natal Province of South Africa, DDT is sprayed annually in homes (indoor residual spraying) to control the mosquito vector of malaria. In the northern part of the Province, samples of free-range chicken meat (n = 48) and eggs (n = 13), and commercially produced chicken meat (n = 6) and eggs (n = 11), were collected and analysed. Of the free-range chicken meat samples, 94% (45/48) contained DDTs (ΣDDTs median 6.1 ng/g wet weight [ww], maximum 79.1 ng/g ww). Chicken egg contents were also contaminated (ΣDDTs in free-range eggs median 9544 ng/g ww, maximum 96.666 ng/g ww; and in commercial eggs median 1.3 ng/g ww, maximum 4.6 ng/g ww). The predominant DDT congener detected was p,p'-DDE in both free-range meat (>63%) and eggs (>66%), followed by p,p'-DDT and then p,p'-DDD. Based on estimated daily intake values, calculated human risk ratio (carcinogenic) values were >1 for DDTs detected in both free-range chicken products. Consumption of free-range eggs poses a particularly high health risk.


Assuntos
Galinhas , DDT/análise , DDT/metabolismo , Contaminação de Alimentos/análise , Carne/análise , Óvulo/química , Animais , Humanos , Medição de Risco , África do Sul
10.
J Periodontal Res ; 52(3): 594-602, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28233905

RESUMO

BACKGROUND AND OBJECTIVE: Periodontal disease is a chronic inflammatory disease caused by bacterial infection that can lead to tooth loss. Gingival crevicular fluid can be collected easily and noninvasively. We previously discovered the presence of apolipoprotein B (apoB), the main constituent of low-density lipoprotein, and oxidized low-density lipoprotein (oxLDL) in the gingival crevicular fluid of healthy subjects. In this study, we investigated whether periodontal conditions affect the levels of apoB and oxLDL in gingival crevicular fluid. MATERIAL AND METHODS: The study population comprised 11 patients with chronic periodontitis. A pair of gingival crevicular fluid samples was collected from each patient at a healthy site and at a site with periodontitis (baseline samples). Thereafter, gingival crevicular fluid samples were collected from the same patients again at 4 and 8 wk after scaling and root planing (SRP). The levels of apoB, oxLDL, protein and cytokines in gingival crevicular fluid, in addition to gingival crevicular fluid volume, were measured. RESULTS: At baseline, the levels of apoB and oxLDL in gingival crevicular fluid were higher at the sites with periodontitis than at the healthy sites. The levels of apoB and oxLDL at periodontal sites decreased after SRP. The level of oxLDL in gingival crevicular fluid correlated well with the probing pocket depth. The oxLDL : apoB ratio in gingival crevicular fluid was significantly higher than that in plasma. CONCLUSIONS: The levels of apoB and oxLDL in gingival crevicular fluid change according to the periodontal tissue conditions.


Assuntos
Apolipoproteínas B/análise , Periodontite Crônica/metabolismo , Líquido do Sulco Gengival/química , Lipoproteínas LDL/análise , Idoso , Periodontite Crônica/terapia , Citocinas/análise , Índice de Placa Dentária , Raspagem Dentária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice Periodontal , Aplainamento Radicular
11.
Vet Comp Oncol ; 15(3): 731-739, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26766288

RESUMO

5-Aminolevulinic acid (5-ALA) is widely used in photodynamic detection (PDD) and therapy. We evaluated the pharmacokinetics of 5-ALA-induced porphyrins and its effectiveness in PDD in dogs with mammary gland tumours (MGTs) following oral administration. Healthy dogs and those with MGTs (nine each) were orally administered 4 mg kg-1 5-ALA. Protoporphyrin IX (PpIX) was not detected in the plasma of healthy dogs but it peaked in dogs with MGT at 2 h after 5-ALA administration. In the PDD study, 16 dogs with MGT were orally administered 40 mg kg-1 5-ALA, and MGT but not normal tissue showed red fluorescence after 2-4 h. Photon counts were 6635-63 890 and 59-4011 (median, 19 943 and 919) for MGT and non-tumour tissues, respectively. Cell density strongly correlated with PpIX photon counts of MGT tissue of the dogs (R = 0.743, P = 0.0009). We suggest that 5-ALA-PDD might be an effective diagnostic tool for MGTs.


Assuntos
Ácido Aminolevulínico/farmacologia , Doenças do Cão/diagnóstico , Neoplasias Mamárias Animais/diagnóstico , Fármacos Fotossensibilizantes/farmacologia , Espectrometria de Fluorescência/veterinária , Administração Oral , Ácido Aminolevulínico/administração & dosagem , Animais , Cães , Feminino , Fármacos Fotossensibilizantes/administração & dosagem , Porfirinas/metabolismo
12.
J Vet Pharmacol Ther ; 39(5): 478-87, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26970544

RESUMO

Research on drug metabolism and pharmacokinetics in large animal species including the horse is scarce because of the challenges in conducting in vivo studies. The metabolic reactions catalyzed by cytochrome P450s (CYPs) are central to drug pharmacokinetics. This study elucidated the characteristics of equine CYPs using diazepam (DZP) as a model compound as this drug is widely used as an anesthetic and sedative in horses, and is principally metabolized by CYPs. Diazepam metabolic activities were measured in vitro using horse and rat liver microsomes to clarify the species differences in enzyme kinetic parameters of each metabolite (temazepam [TMZ], nordiazepam [NDZ], p-hydroxydiazepam [p-OH-DZP], and oxazepam [OXZ]). In both species microsomes, TMZ was the major metabolite, but the formation rate of p-OH-DZP was significantly less in the horse. Inhibition assays with a CYP-specific inhibitors and antibody suggested that CYP3A was the main enzyme responsible for DZP metabolism in horse. Four recombinant equine CYP3A isoforms expressed in Cos-7 cells showed that CYP3A96, CYP3A94, and CYP3A89 were important for TMZ formation, whereas CYP3A97 exhibited more limited activity. Phylogenetic analysis suggested diversification of CYP3As in each mammalian order. Further study is needed to elucidate functional characteristics of each equine CYP3A isoform for effective use of diazepam in horses.


Assuntos
Citocromo P-450 CYP3A/metabolismo , Diazepam/farmacocinética , Cavalos/metabolismo , Hipnóticos e Sedativos/farmacocinética , Animais , Células COS/enzimologia , Células COS/metabolismo , Chlorocebus aethiops , Citocromo P-450 CYP3A/genética , Diazepam/análogos & derivados , Masculino , Microssomos Hepáticos/enzimologia , Microssomos Hepáticos/metabolismo , Nordazepam/farmacocinética , Oxazepam/farmacocinética , Filogenia , Isoformas de Proteínas/metabolismo , Ratos , Ratos Sprague-Dawley , Especificidade da Espécie , Temazepam/farmacocinética
13.
J Vet Pharmacol Ther ; 38(2): 190-5, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25229839

RESUMO

Large interspecies differences in avian xenobiotic metabolism have been revealed by microsome-based studies, but specific enzyme isoforms in different bird species have not yet been compared. We have previously shown that CYP2C23 genes are the most induced CYP isoforms in chicken liver. In this study, we collected partial CYP2C23a gene sequences from eight avian species (ostrich, blue-eared pheasant, snowy owl, great-horned owl, Chilean flamingo, peregrin falcon, Humboldt penguin, and black-crowned night heron) selected to cover the whole avian lineage: Paleognathae, Galloanserae, and Neoaves. Genetic analysis showed that CYP2C23 genes of Galloanserae species (chicken and blue-eared pheasant) had unique characteristics. We found some duplicated genes (CYP2C23a and CYP2C23b) and two missing amino acid residues in Galloanserae compared to the other two lineages. The genes have lower homology than in other avian lineages, which suggests Galloanserae-specific rapid evolutionary changes. These genetic features suggested that the Galloanserae are not the most representative avian species, considering that the Neoaves comprise more than 95% of birds. Moreover, we succeeded in synthesizing an antipeptide polyclonal antibody against the region of CYP2C23 protein conserved in avians. However, comparative quantitation of CYP2C23 proteins in livers from six species showed that expression levels of these proteins differed no more than fourfold. Further study is needed to clarify the function of avian CYP2C23 proteins.


Assuntos
Aves/metabolismo , Clonagem Molecular , Sistema Enzimático do Citocromo P-450/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Fígado/enzimologia , Sequência de Aminoácidos , Animais , Aves/genética , Sistema Enzimático do Citocromo P-450/genética , Dados de Sequência Molecular , Filogenia , Especificidade da Espécie
14.
Br J Cancer ; 109(2): 401-7, 2013 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-23820256

RESUMO

BACKGROUND: This study investigated the usefulness of a novel inflammation-based prognostic system, named the COP-NLR (COmbination of Platelet count and Neutrophil to Lymphocyte Ratio), for predicting the postoperative survival of patients with colorectal cancer (CRC). METHODS: The COP-NLR was calculated on the basis of data obtained on the day of admission: patients with both an elevated platelet count (>30 × 10(4) mm(-3)) and an elevated NLR (>3) were allocated a score of 2, and patients showing one or neither were allocated a score of 1 or 0, respectively. RESULTS: Four-hundred and eighty patients were enrolled. Multivariate analysis of clinical characteristics selected by univariate analysis showed that the COP-NLR (1, 2/0) (odds ratio, 0.464; 95% confidence interval, 0.267-0.807; P=0.007) had an association with cancer-specific survival, along with pathology, lymph node metastasis, the serum levels of carcinoembryonic antigen, C-reactive protein and albumin, and the Glasgow Prognostic Score. Kaplan-Meier analysis and log-rank test revealed that the COP-NLR was able to divide such patients into three independent groups (P<0.001). CONCLUSION: The COP-NLR is considered to be a useful predictor of postoperative survival in patients with CRC.


Assuntos
Plaquetas/patologia , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/cirurgia , Linfócitos/patologia , Neutrófilos/patologia , Idoso , Idoso de 80 Anos ou mais , Contagem de Células Sanguíneas , Neoplasias Colorretais/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
15.
Poult Sci ; 92(7): 1921-9, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23776281

RESUMO

A 1,000-fold difference has been reported in dioxin sensitivity between avian species. This difference is because the 2 amino acids in the type 1 aryl hydrocarbon receptor (AhR1), at positions 325 and 381, correspond to Leu324 and Ser380 in chickens. The chicken had been reported to be the only avian species to possess a sensitive form of AhR1. This is the first study to reveal that the ostrich (Struthio camelus), a nonchicken species, also has a pair of amino acids (Ile-325 and Ser-381) that show high ligand affinity. However, the alignment of the AhR1 cDNA sequence showed that the AhR sequence in the ostrich was different than that of other avian species even though the critical amino acids were observed at positions 325 and 381. Ostrich AhR1 was also evaluated in a heterologous expression study. Ostrich AhR1 showed very high transcriptional activity of the cytochrome P450 1A5 (CYP1A5) gene in African Green Monkey Cercopithecus aethiops kidney cells (COS-7) treated with Sudan III. In primary cultures of ostrich kidney cells, CYP1A5 expression was induced by Sudan III at a lower (or almost identical) concentration to that observed in the chicken. The present study revealed a new AhR ligand sensitive avian species (i.e., the ostrich).


Assuntos
Hidrocarboneto de Aril Hidroxilases/metabolismo , Regulação da Expressão Gênica/fisiologia , Struthioniformes/metabolismo , Sequência de Aminoácidos , Animais , Hidrocarboneto de Aril Hidroxilases/genética , Células Cultivadas , Galinhas/metabolismo , Rim/citologia , Luciferases/metabolismo , Dados de Sequência Molecular , Filogenia , Especificidade da Espécie , Distribuição Tecidual
16.
Br J Pharmacol ; 166(2): 788-800, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22168428

RESUMO

BACKGROUND AND PURPOSE: Dopamine released from the endings of descending dopaminergic nerve fibres in the spinal cord may be involved in modulating functions such as locomotion and nociception. Here, we examined the effects of dopamine on spinal synaptic transmissions in rats. EXPERIMENTAL APPROACH: Spinal reflex potentials, monosynaptic reflex potential (MSR) and slow ventral root potential (sVRP), were measured in the isolated spinal cord of the neonatal rat. Dopamine release was measured by HPLC. KEY RESULTS: Dopamine at lower concentrations (<1 µM) depressed sVRP, which is a C fibre-evoked polysynaptic response and believed to reflect nociceptive transmission. At higher concentrations (>1 µM), in addition to a potent sVRP depression, dopamine depolarized baseline potential and slightly depressed MSR. Depression of sVRP by dopamine was partially reversed by dopamine D(1) -like but not by D(2) -like receptor antagonists. SKF83959 and SKF81297, D(1) -like receptor agonists, and methamphetamine, an endogenous dopamine releaser, also caused the inhibition of sVRP. Methamphetamine also depressed MSR, which was inhibited by ketanserin, a 5-HT(2A/2C) receptor antagonist. Methamphetamine induced the release of dopamine and 5-HT from spinal cords, indicating that the release of endogenous dopamine and 5-HT depresses sVRP and MSR respectively. CONCLUSION AND IMPLICATIONS: These results suggested that dopamine at lower concentrations preferentially inhibited sVRP, which is mediated via dopamine D(1) -like and other unidentified receptors. The dopamine-evoked depression is involved in modulating the spinal functions by the descending dopaminergic pathways.


Assuntos
Dopamina/farmacologia , Receptores de Dopamina D1/fisiologia , Medula Espinal/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Benzazepinas/farmacologia , Dopaminérgicos/farmacologia , Antagonistas de Dopamina/farmacologia , Feminino , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/fisiologia , Técnicas In Vitro , Masculino , Metanfetamina/farmacologia , Ratos , Ratos Wistar , Receptores de Dopamina D1/agonistas , Receptores de Dopamina D1/antagonistas & inibidores , Reflexo/efeitos dos fármacos , Reflexo/fisiologia , Medula Espinal/fisiologia , Transmissão Sináptica/fisiologia
17.
Int J Immunogenet ; 39(2): 170-82, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22117600

RESUMO

The African buffalo (Syncerus caffer) has been implicated as the reservoir of several bovine infectious agents. However, there is insufficient information on the protective immune responses in the African buffalo, particularly in infected animals. In this study, we analysed Th1 cytokines IL-2 and IFN-γ, and Th2 cytokines IL-4 and IL-10. The cloned cDNA of IL-2, IL-4, IL-10 and IFN-γ contained an open reading frame of 468, 501, 408 and 540 nucleotides, encoding polypeptides of 155, 166, 135 and 179 amino acids, respectively. Nucleotide sequence homology of IL-2, IFN-γ and IL-4 was more than 98% between the African buffalo and cattle, which resulted in identical polypeptides. Meanwhile, IL-10 gene of African buffalo and cattle had 95% homology in nucleotide sequence, corresponding to thirteen amino acid residues substitution. Cysteine residues and potential glycosylation sites were conserved within the family Bovinae. Phylogenetic analyses including cytokines of the African buffalo placed them within a cluster comprised mainly of species belonging to the order Artiodactyla, including cattle, water buffalo, sheep, goat, pig and artiodactyl wildlife. A deeper understanding of the structure of these cytokines will shed light on their protective role in the disease-resistant African buffalo in comparison with other closely related species.


Assuntos
Búfalos/genética , Interferon gama/genética , Interleucina-10/genética , Interleucina-2/genética , Interleucina-4/genética , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Sequência de Bases , Búfalos/imunologia , Bovinos , Clonagem Molecular , Cisteína/genética , DNA Complementar/genética , Glicosilação , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Homologia de Sequência do Ácido Nucleico
18.
Poult Sci ; 90(12): 2775-81, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22080016

RESUMO

Warfarin, a coumarin rodenticide, is commonly used worldwide for rodent control, and is often reported as the cause for poisoning accidents in nontarget animals, in particular bird species. However, the metabolism of warfarin in birds is still unclear. In a previous study, we found an unknown warfarin metabolite in chicken cytosolic fractions. In the present study, we aimed to clarify the cytosolic warfarin metabolites in chickens compared with those in rats. The cytosol fractions of both chicken and rat livers showed the metabolic activity of 2 diastereomers and 2 enantiomers of warfarin alcohol. In chicken cytosol, we found that the production level of (S)-warfarin-(S)-alcohol was markedly higher (32-fold) than that in rat cytosol. From the results of the inhibition assay, we finally suggest that aldehyde oxidase may mainly contribute to the warfarin alcohol products in chicken cytosol.


Assuntos
Galinhas/metabolismo , Rodenticidas/farmacocinética , Varfarina/farmacocinética , Animais , Citosol/metabolismo , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Ratos , Varfarina/química , Varfarina/metabolismo
19.
Rev Sci Instrum ; 82(7): 076104, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21806238

RESUMO

We have developed a laser Doppler velocimeter (LDV) for measuring velocity distributions in blood vessels. We converted a transmission-based LDV into a reflection-based LDV to make it suitable for clinical applications. The velocity distribution image of a serpentine flow channel obtained could be qualitatively explained by the numerical results. Finally, we evaluated the system by using it to measure injection of blood into a glass tube by a syringe pump. The results obtained demonstrate that erythrocytes can be used as seeding particles for the reflection-type micro multipoint LDV. The results obtained are useful as basic data for clinical applications.


Assuntos
Vasos Sanguíneos/fisiologia , Fluxometria por Laser-Doppler/instrumentação , Animais , Hemorreologia , Masculino , Camundongos , Microcirculação , Imagem Molecular
20.
Br J Surg ; 98(9): 1284-90, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21633950

RESUMO

BACKGROUND: The aim of this study was to evaluate the influence of the duration of hepatic vascular inflow clamping (Pringle time) on the survival of patients with any type of liver background (not only cirrhosis) undergoing liver resection for hepatocellular carcinoma (HCC). METHODS: Patients who underwent liver resection between April 2000 and December 2008 for HCC using the Pringle manoeuvre were identified retrospectively from an institutional database and divided into two groups: group 1 had a Pringle time of 60 min or less, and group 2 a Pringle time of more than 60 min. Univariable and multivariable analyses were performed to identify predictors of postoperative survival. Kaplan-Meier analysis was used to compare overall survival between the groups. RESULTS: A total of 357 patients were enrolled; 242 patients had a Pringle time of 60 min or less (group 1), and 115 patients had a Pringle time of more than 60 min (group 2). Patients in group 2 had a shorter overall survival than those in group 1 (P = 0·010). Univariable analyses showed that type of HCC (primary versus recurrent), maximum tumour diameter, hepatic venous infiltration, platelet count, serum protein induced by vitamin K absence or antagonist II level, blood loss (700 ml or less versus more than 700 ml), duration of operation (300 min or less versus more than 300 min) and Pringle time (60 min or less versus more than 60 min) were predictive of postoperative survival. Multivariable analysis indicated that only Pringle time was associated with postoperative survival (odds ratio 1·83, 95 per cent confidence interval 1·08 to 3·10; P = 0·024). CONCLUSION: Longer Pringle time is an important predictor of shorter postoperative survival in patients undergoing liver resection for HCC.


Assuntos
Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Perda Sanguínea Cirúrgica/mortalidade , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Constrição , Feminino , Humanos , Estimativa de Kaplan-Meier , Tempo de Internação , Fígado/irrigação sanguínea , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...