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1.
Regul Toxicol Pharmacol ; 117: 104779, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32888975

RESUMO

Maize plants containing event DP-2Ø2216-6 (DP202216), which confers herbicide tolerance through expression of phosphinothricin acetyltransferase and enhanced grain yield potential via temporal modulation of the native ZMM28 protein, were developed for commercialization. To address current regulatory expectations, a mandatory 90-day rodent feeding study was conducted to support the safety assessment. Diets containing 50% by weight of ground maize grain from DP202216, non-transgenic control, and 3 non-transgenic reference varieties, were fully characterized, along with the grain, and diets were fed to Crl:CD®(SD) rats for at least 90 days. As anticipated, no biologically-relevant effects or toxicologically-significant differences were observed on survival, body weight/gain, food consumption/efficiency, clinical and neurobehavioral evaluations, ophthalmology, clinical pathology (hematology, coagulation, clinical chemistry, urinalysis), organ weights, or gross and microscopic pathology parameters in rats fed a diet containing up to 50% DP202216 maize grain when compared with rats fed diets containing control or reference maize grains. The results of this study support the conclusion that maize grain from plants containing event DP-2Ø2216-6 is as safe and nutritious as maize grain not containing the event and add to the significant existing database of rodent subchronic studies demonstrating the absence of hazards from consumption of edible fractions of genetically modified plants.


Assuntos
Aminobutiratos/administração & dosagem , Ração Animal , Ingestão de Alimentos/efeitos dos fármacos , Herbicidas/administração & dosagem , Plantas Geneticamente Modificadas , Zea mays , Aminobutiratos/toxicidade , Ração Animal/toxicidade , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Ingestão de Alimentos/fisiologia , Feminino , Herbicidas/toxicidade , Masculino , Plantas Geneticamente Modificadas/toxicidade , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Zea mays/toxicidade
2.
Am J Transplant ; 17(9): 2312-2325, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28276660

RESUMO

Despite the introduction of novel and more targeted immunosuppressive drugs, the long-term survival of kidney transplants has not improved satisfactorily. Early antigen-independent intragraft inflammation plays a critical role in the initiation of the alloimmune response and impacts long-term graft function. Complement activation is a key player both in ischemia/reperfusion injury (IRI) as well as in adaptive antigraft immune response after kidney transplantation. Since the alternative pathway (AP) amplifies complement activation regardless of the initiation pathways and renal IR injured cells undergo uncontrolled complement activation, we speculated whether selective blockade of AP could be a strategy for prolonging kidney graft survival. Here we showed that Balb/c kidneys transplanted in factor b deficient C57 mice underwent reduced IRI and diminished T cell-mediated rejection. In in vitro studies, we found that fb deficiency in T cells and dendritic cells conferred intrinsic impaired alloreactive/allostimulatory functions, respectively, both in direct and indirect pathways of alloantigen presentation. By administering anti-fB antibody to C57 wt recipients in the early post Balb/c kidney transplant phases, we documented that inhibition of AP during both ischemia/reperfusion and early adaptive immune response is necessary for prolonging graft survival. These findings may have implication for the use of AP inhibitors in clinical kidney transplantation.


Assuntos
Ativação do Complemento/imunologia , Fator B do Complemento/deficiência , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/imunologia , Transplante de Rim/efeitos adversos , Traumatismo por Reperfusão/prevenção & controle , Linfócitos T/imunologia , Aloenxertos , Animais , Fator B do Complemento/genética , Rejeição de Enxerto/etiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Traumatismo por Reperfusão/etiologia
3.
Toxicol Appl Pharmacol ; 336: 66-74, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29051111

RESUMO

Multiplex biomarker panel assays would enable early de-risking of discovery compound related kidney safety liabilities. The objective of this study was to evaluate the usefulness of the Myriad RBM Human KidneyMAP (Multi-Analyte Profile)® v.1.0 panel to detect experimental nephrotoxicity in Cynomolgus monkeys following a single intravenous administration of cisplatin (2.5mg/kg). Urine samples were collected at baseline on day -2; at approximately 4hr post-dose on day 1; and on days 4, 9, 15 and/or 20. Blood samples were collected at predose on day -2; at 4hr post-dose on day 1; and on days 2, 5, 10 and/or 21. Changes in toxicokinetic and biochemistry parameters in plasma, qualitative/quantitative urinalysis parameters, and urinary kidney safety biomarkers were assessed. Kidney tissues were collected on days 2, 5, 10 and 21 for routine microscopy. Cisplatin-induced tubular alterations were characterized by acute and progressive cortical tubular degeneration/necrosis, regeneration, tubular dilation and proteinaceous cast in the absence of statistically significant changes in traditional plasma biochemistry and urinalysis parameters. When normalized to urinary creatinine, cisplatin-induced significant increases in urinary levels of kidney injury molecule 1 (females on day 4), increases in calbindin D28k (males and females on day 4), decreases in Tamm-Horsfall glycoprotein (males on days 1, 4 and 9), and increases in clusterin (females and males on days 15 and 20, respectively), when compared to concurrent controls. This study revealed the usefulness of the Human KidneyMAP® multiplex panel when measuring changes in urine-based biomarkers to reliably detect cisplatin-induced acute/progressive cortical tubular injury in male and female Cynomolgus monkeys.


Assuntos
Antineoplásicos/toxicidade , Biomarcadores/urina , Cisplatino/toxicidade , Nefropatias/induzido quimicamente , Nefropatias/urina , Túbulos Renais/efeitos dos fármacos , Testes de Toxicidade/métodos , Animais , Biomarcadores/sangue , Nitrogênio da Ureia Sanguínea , Calbindinas/urina , Clusterina/urina , Creatinina/sangue , Feminino , Receptor Celular 1 do Vírus da Hepatite A/metabolismo , Humanos , Nefropatias/sangue , Nefropatias/patologia , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Macaca fascicularis , Masculino , Modelos Animais , Valor Preditivo dos Testes , Fatores Sexuais , Especificidade da Espécie , Fatores de Tempo , Toxicocinética , Urinálise , Uromodulina/urina
4.
Diabet Med ; 34(2): 189-196, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27589252

RESUMO

AIM: To investigate the safety and efficacy of insulin degludec/liraglutide (IDegLira), a novel combination product, as add-on therapy for people with Type 2 diabetes uncontrolled on sulphonylurea therapy. METHODS: In this 26-week, double-blind trial, adults with Type 2 diabetes [HbA1c 53-75 mmol/mol (7.0-9.0%)] were randomized to IDegLira (n = 289) or placebo (n = 146) as add-on to pre-trial sulphonylurea ± metformin, titrating to a fasting glycaemic target of 4.0-6.0 mmol/l. Treatment initiation was at 10 dose steps, and maximum dose was 50 dose steps (50 units insulin degludec/1.8 mg liraglutide). RESULTS: The mean HbA1c decreased from 63 mmol/mol (7.9%) to 46 mmol/mol (6.4%) with IDegLira and to 57 mmol/mol (7.4%) with placebo [estimated treatment difference -11 mmol/mol (95% CI -13; -10) or -1.02% (95% CI -1.18; -0.87); P < 0.001]. The HbA1c target of 53 mmol/mol (<7%) was achieved by 79.2% of participants in the IDegLira group vs 28.8% in the placebo group [estimated odds ratio 11.95 (95% CI 7.22; 19.77); P < 0.001]. Mean weight change was +0.5 kg with IDegLira vs -1.0 kg with placebo [estimated treatment difference 1.48 kg (95% CI 0.90; 2.06); P < 0.001]. Confirmed hypoglycaemia occurred in 41.7 and 17.1% of IDegLira- and placebo-treated participants, respectively, with rates of 3.5 vs 1.4 events/patient-years of exposure [estimated rate ratio 3.74 (95% CI 2.28; 6.13); P < 0.001]. IDegLira was generally well tolerated. The rates of serious adverse events were 20.3 and 8.0 per 100 patient-years of exposure with IDegLira and placebo, respectively, without obvious patterns in the type of events. CONCLUSIONS: IDegLira can be used in people uncontrolled with sulphonylurea ± metformin to improve efficacy with a safety profile in line with previous DUAL trials.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insulina de Ação Prolongada/uso terapêutico , Liraglutida/uso terapêutico , Metformina/uso terapêutico , Compostos de Sulfonilureia/uso terapêutico , Idoso , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Método Duplo-Cego , Combinação de Medicamentos , Quimioterapia Combinada , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/induzido quimicamente , Masculino , Pessoa de Meia-Idade
5.
Infect Immun ; 76(4): 1358-67, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18268029

RESUMO

Most Bacillus cereus toxin production is controlled by the quorum-sensing-dependent, pleiotropic global regulator plcR, which contributes to the organism's virulence in the eye. The purpose of this study was to analyze the effects of B. cereus infection and plcR-regulated toxins on the barrier function of retinal pigment epithelium (RPE) cells, the primary cells of the blood-retina barrier. Human ARPE-19 cells were apically inoculated with wild-type or quorum-sensing-deficient B. cereus, and cytotoxicity was analyzed. plcR-regulated toxins were not required for B. cereus-induced RPE cytotoxicity, but these toxins did increase the rate of cell death, primarily by necrosis. B. cereus infection of polarized RPE cell monolayers resulted in increased barrier permeability, independent of plcR-regulated toxins. Loss of both occludin and ZO-1 expression occurred by 8 h postinfection, but alterations in tight junctions appeared to precede cytotoxicity. Of the several proinflammatory cytokines analyzed, only interleukin-6 was produced in response to B. cereus infection. These results demonstrate the deleterious effects of B. cereus infection on RPE barrier function and suggest that plcR-regulated toxins may not contribute significantly to RPE barrier permeability during infection.


Assuntos
Bacillus cereus/fisiologia , Barreira Hematorretiniana/microbiologia , Barreira Hematorretiniana/patologia , Linhagem Celular , Humanos , Permeabilidade , Transporte Proteico , ATPase Trocadora de Sódio-Potássio/metabolismo , Junções Íntimas/metabolismo
6.
Kidney Int ; 73(4): 379-81, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18235520

RESUMO

The development of effective therapies for acute kidney injury (AKI) has been hindered by delayed diagnosis in the clinical setting, varying definitions of AKI, and limited prognostic information. In a study by Portilla et al., elevations in liver fatty acid-binding protein (L-FABP) were found to predict AKI in children undergoing cardiac surgery. New biomarkers offer the promise of earlier and more accurate diagnosis of AKI. Before they can be deemed clinically useful, however, they must undergo rigorous validation in multiple cohorts.


Assuntos
Ponte Cardiopulmonar/efeitos adversos , Proteínas de Ligação a Ácido Graxo/urina , Nefropatias/diagnóstico , Doença Aguda , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Criança , Proteínas de Ligação a Ácido Graxo/sangue , Humanos , Prognóstico
7.
Hippokratia ; 20(2): 169-171, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28416917

RESUMO

BACKGROUND: Treatment of ruptured hepatocellular carcinoma (HCC) focuses on hemorrhage control and utilizes tumor vascular anatomy to palliate or temporize selected patients with hepatic artery embolization (HAE). Radiofrequency ablation (RFA) and microwave ablation (MWA) are feasible alternatives or adjunct modalities to resection of HCC; the method of energy delivery in MWA allows uniform coagulative necrosis in shorter time compared with RFA. CASE DESCRIPTION: We present the case of an 82-year-old man who presented with a ruptured liver tumor with active intraperitoneal bleeding on angiography. The patient remained hemodynamically stable with evidence of ongoing bleeding following HAE. Tumor destruction and definitive hemostasis were obtained with minimally invasive MWA. CONCLUSION: Tumor rupture remains a negative prognostic factor in the course of HCC. In select patients, MWA allows definitive hemorrhage control with minimal surgical morbidity.  Hippokratia 2016, 20(2): 169-171.

8.
Mol Biochem Parasitol ; 92(1): 111-22, 1998 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-9574915

RESUMO

The processing and localization of Plasmodium falciparum rhoptry-associated protein 1 (RAP-1) products were examined using polyclonal and monoclonal antibodies raised to a recombinant protein containing residues 1-294 of RAP-1. Immunoblot and epitope mapping results with antibodies that selectively bound epitopes in the RAP-1 products Pr86, p82, and p67 showed that p82 and p67 are formed from Pr86 by progressive removal of epitopes from the amino-terminus of the RAP-1 coding sequence. The capacity of Pr86 to form complexes was revealed after size fractionation of parasite proteins radiolabeled in the presence of brefeldin A to prevent processing of Pr86. Fractions containing complexed Pr86 also contained the RAP-2 product p39 and the RAP-3 product p37, suggesting that Pr86, p39 and p37 may form complexes similar to complexes previously reported for p82 and p67 with p39 or p37. Immunofluorescence localization and immunoblot studies revealed that Pr86 is present in the rhoptries, but only transiently, and that it is not detected in segmenting schizonts or extracellular merozoites. p67 and p82, on the other hand, were shown to be major RAP-1 components in purified merozoites. Neither p67 nor p82 were relocalized from the intracellular rhoptries to the merozoite surface under conditions that promoted relocalization of the rhoptry protein PF83/apical membrane antigen 1. These results suggest that processing of Pr86 begins after Pr86 complexes are transported to the forming rhoptries and that two site-selective processing reactions occur in the rhoptries, a rapid cleavage of Pr86 to p82 and a delayed cleavage of p82 to p67. Since p67 is missing from ring-stage parasites (Howard et al., Am J Trop Med Hyg, 1984;33:1055 59), the present results indicate there is a narrow time during which p67 may play a role in merozoite invasion of erythrocytes.


Assuntos
Antígenos de Protozoários/metabolismo , Organelas/metabolismo , Plasmodium falciparum/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas de Protozoários/metabolismo , Animais , Antibacterianos/farmacologia , Anticorpos Antiprotozoários , Brefeldina A , Compartimento Celular , Diferenciação Celular , Ciclopentanos/farmacologia , Epitopos , Macrolídeos , Plasmodium falciparum/citologia , Ligação Proteica , Inibidores da Síntese de Proteínas/farmacologia
9.
Drugs ; 57(1): 19-29, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9951949

RESUMO

It is widely accepted that the most challenging goal in the management of patients with diabetes mellitus is to achieve blood glucose levels as close to normal as possible. In general, normalising postprandial blood glucose levels is more difficult than normalising fasting hyperglycaemia. In addition, some epidemiological studies suggest that postprandial hyperglycaemia (PPHG) or hyperinsulinaemia are independent risk factors for the development of macrovascular complications of diabetes mellitus. Recently, several drugs with differing pharmacodynamic profiles have been developed which target PPHG. These include insulin lispro, amylin analogues, alpha-glucosidase inhibitors and meglitinide analogues. Insulin lispro has a more rapid onset of action and shorter duration of efficacy compared with regular human insulin. In clinical trials, the use of insulin lispro was associated with improved control of PPHG and a reduced incidence of hypoglycaemic episodes. Repaglinide, a meglitinide analogue, is a short-acting insulinotropic agent which. when given before meals, stimulates endogenous insulin secretions and lowers postprandial hyperglycaemic excursions. Both insulin lispro and repaglinide are associated with postprandial hyperinsulinaemia. In contrast, amylin analogues reduce PPHG by slowing gastric emptying and delivery of nutrients to the absorbing surface of the gut. Alpha-Glucosidase inhibitors such as acarbose, miglitol and voglibose also reduce PPHG primarily by interfering with the carbohydrate-digesting enzymes and delaying glucose absorption. With the availability of agents which preferentially reduce postprandial blood glucose excursions, it is now possible to achieve glycaemic goals in a larger proportion of individuals with diabetes mellitus.


Assuntos
Inibidores Enzimáticos/uso terapêutico , Hiperglicemia/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Período Pós-Prandial , 1-Desoxinojirimicina/análogos & derivados , Acarbose , Amiloide/uso terapêutico , Carbamatos/uso terapêutico , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/fisiopatologia , Glucosamina/análogos & derivados , Glucosamina/uso terapêutico , Glibureto/uso terapêutico , Humanos , Hiperglicemia/dietoterapia , Hiperglicemia/fisiopatologia , Imino Piranoses , Inositol/análogos & derivados , Inositol/uso terapêutico , Insulina/análogos & derivados , Insulina/uso terapêutico , Insulina Lispro , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Piperidinas/uso terapêutico , Trissacarídeos/uso terapêutico
10.
Environ Health Perspect ; 109 Suppl 2: 309-14, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11359700

RESUMO

Fumonisin B1(FB1) is a fungal metabolite of Fusarium verticillioides (= F. moniliforme), a fungus that grows on many crops worldwide. Previous studies demonstrated that male BD IX rats consuming diets containing 50 ppm fumonisin B1 developed hepatocellular carcinomas. In our recent studies, diets containing FB1 at 50 ppm or higher concentrations induced renal tubule carcinomas in male F344/N/Nctr BR rats and hepatocellular carcinomas in female B6C3F1/Nctr BR mice. The carcinogenicity of FB1 in rats and mice is not due to DNA damage, as several laboratories have demonstrated that FB1 is not a genotoxin. FB1 induces apoptosis in cells in vitro. Including FB1 in the diets of rats results in increased hepatocellular and renal tubule epithelial cell apoptosis. In studies with F344/N/Nctr BR rats consuming diets containing up to 484 ppm FB1 for 28 days, female rats demonstrated more sensitivity than male rats in the induction of hepatocellular apoptosis and mitosis. Conversely, induction of renal tubule apoptosis and regeneration were more pronounced in male than in female rats. Induction of renal tubule apoptosis and hyperplasia correlated with the incidence of renal tubule carcinomas that developed in the 2-year feeding study with FB1 in the F344/N/Nctr BR rats. The data are consistent with the hypothesis that the induction of renal tubule carcinomas in male rats could be partly due to the continuous compensatory regeneration of renal tubule epithelial cells in response to the induction of apoptosis by fumonisin B1.


Assuntos
Ácidos Carboxílicos/toxicidade , Carcinógenos Ambientais/toxicidade , Fumonisinas , Neoplasias Renais/induzido quimicamente , Rim/efeitos dos fármacos , Neoplasias Hepáticas Experimentais/induzido quimicamente , Micotoxinas/toxicidade , Regeneração/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Bioensaio , Sobrevivência Celular , Epitélio/efeitos dos fármacos , Epitélio/fisiopatologia , Feminino , Hepatócitos/efeitos dos fármacos , Rim/fisiologia , Neoplasias Renais/fisiopatologia , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/fisiopatologia , Neoplasias Hepáticas Experimentais/fisiopatologia , Masculino , Mitose/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344
11.
Am J Trop Med Hyg ; 59(2): 208-16, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9715934

RESUMO

Humoral and cellular responses were examined among natives and migrants in an area of the Amazon region of Brazil. Rhoptry-associated protein-1 (RAP-1) and RAP-2 expressed in Escherichia coli expression systems, a peptide corresponding to the epitope bound by inhibitory anti-RAP-1 antibodies, and four other RAP-1 and RAP-2 synthetic peptides were used in these studies. Plasma from the native population had greater IgG reactivity to the N-terminal third of RAP-1 than the migrant population; both populations had low levels of IgM to this region of RAP-1. The IgG reactivity to RAP-2 and to the C-terminal third of RAP-1, as well as for all the peptides, including the peptide from the inhibitory domain, were low or absent in both populations. In contrast, there were a high number of subjects with an IgM response to the peptides. Cellular responses were measured by proliferation of peripheral blood mononuclear cells (PBMC) and, in some subjects, by reverse transcription-polymerase chain reaction for interleukin-2 (IL-2), interferon-gamma (IFN-gamma), IL-4, and IL-10. Proliferation of PBMC was low when stimulated by recombinant proteins, peptides, or parasite lysate. Both RAP-1 and RAP-2 stimulated cytokine production by donor T cells; IL-2, IL-4, and IFN-gamma RNA transcripts were observed in response to recombinant proteins and parasite lysate, but with no uniform trends. From the observed antibody responses, RAP-1 appears to be more immunogenic than RAP-2.


Assuntos
Anticorpos Antiprotozoários/biossíntese , Antígenos de Protozoários/imunologia , Malária Falciparum/imunologia , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/química , Brasil/epidemiologia , Criança , Citocinas/biossíntese , Feminino , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Ativação Linfocitária , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/química , Proteínas Recombinantes/química , Proteínas Recombinantes/imunologia , Migrantes
12.
Brain Res Bull ; 3(5): 541-8, 1978.
Artigo em Inglês | MEDLINE | ID: mdl-122719

RESUMO

The effect of tetraethylthiuramdisulfide (disulfiram) on the catabolism of dopamine within discrete regions of the brain was investigated in the unrestrained rat. After a guide cannula had been implanted stereotaxically, a given subcortical site was radiolabeled with 14C-dopamine (DA) by microinjecting 2.0 mu Ci in 2.0 microliters. Successive push-pull perfusates collected from each tissue were assayed by paper electrophoresis for the separation of DA metabolites. When disulfiram, a potent aldehyde dehydrogenase (ALDH) inhibitor, was given intragastrically in a clinically efficacious dose of 200 mg, the formation of the acids DOPAC and HVA was inhibited within perfusates of the caudate nucleus and nucleus accumbens. However, following disulfiram treatment, the proportion of alcohol metabolites did not differ from the control level in the untreated rat. The level of ALDH decreased by approximately 50% in these subcortical nuclei following the inhibition of the enzyme by disulfiram. Conversely, in samples of perfusate obtained from 14C-labeled sites within inferofrontal cortex, periform cortex, diagonal band of Broca, lateral-posterior caudate nucleus, tuberculum olfactorium, lateral olfactory tract or the olfactory nuclear complex, the proportion of DA metabolites remained stable. Generally, a low rate of deamination of the exogenously injected DA occurred within perfusion sites in the ventrobasal forebrain, whereas an intermediate rate of deamination was noted in samples collected at more dorsal loci. Thus, clearcut regional differences in DA catabolism occur in the brain of the living animal, which may depend upon the characteristics of the dopaminergic-rich area of the rat's brain.


Assuntos
Química Encefálica/efeitos dos fármacos , Dissulfiram/farmacologia , Dopamina/metabolismo , Álcoois/metabolismo , Aldeídos/metabolismo , Animais , Masculino , Perfusão , Ratos , Ratos Endogâmicos
13.
Drugs Aging ; 11(6): 433-49, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9413701

RESUMO

Vitamin supplementation in large dosages is increasingly common in the older population. Often, such supplementation is used in an attempt to improve an individual's health status. There have been claims that the effects of vitamins halt the normal aging process or prevent and cure disease. However, several recent studies have failed to demonstrate the efficacy of vitamin supplementation in preventing several types of cancer. In moderate dosages, supplementation with vitamin E (tocopherols) shows promise as a lipid antioxidant, and may reduce the risk of coronary heart disease. However, before vitamin E becomes an accepted medical therapy, further long term studies must be undertaken to examine the safety and efficacy of such therapy. An adequate intake of vitamins should be ensured by adherence to a well balanced diet. However, the elderly are prone to circumstances that may prevent them from eating a balanced diet. In addition, there are several age-related medical conditions that may predispose individuals to dietary and vitamin deficiencies. To prevent vitamin deficiency diseases and their associated morbidity, modest vitamin supplementation may be necessary. However, supplementation should be reserved for individuals with documented deficiency or who are at risk of developing such deficiencies, especially those who are homebound or institutionalised. Vitamins taken in large dosages should be considered as drugs. These medicines, which are obtainable over-the-counter, should be carefully regulated to prevent toxicity.


Assuntos
Suplementos Nutricionais , Vitaminas/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/efeitos dos fármacos , Antioxidantes/uso terapêutico , Ácido Ascórbico/uso terapêutico , Deficiência de Vitaminas/tratamento farmacológico , Carotenoides/uso terapêutico , Interações Medicamentosas , Humanos , Pessoa de Meia-Idade , Retinoides/uso terapêutico , Complexo Vitamínico B/uso terapêutico , Vitamina D/uso terapêutico , Vitamina E/uso terapêutico , Vitamina K/uso terapêutico , Vitaminas/efeitos adversos
14.
Clin Geriatr Med ; 15(2): 255, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10339632

RESUMO

Plasma concentration of glucose is found within a relatively narrow range of values for most animal species, yet it has little correlation with maximum lifespan; however, hyperglycemia in most animals is associated with premature death. This article presents evidence for hyperglycemia-induced tissue toxicity and discusses potential mechanisms of glucotoxicity and implications for the aging organism.


Assuntos
Complicações do Diabetes , Glucose/metabolismo , Hiperglicemia/etiologia , Fatores Etários , Idoso , Animais , Feminino , Glucose/efeitos adversos , Humanos , Hiperglicemia/fisiopatologia , Masculino , Estresse Oxidativo , Medição de Risco
15.
Adv Exp Med Biol ; 392: 237-50, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8850621

RESUMO

Fumonisin B1 is a mycotoxin produced by Fusarium moniliforme, a fungus that infects corn and other grains in the U.S. Fumonisin ingestion causes a variety of effects including equine leukoencephalomalacia and porcine pulmonary edema, and has been associated epidemiologically with human esophageal cancer. Fumonisin B1 produces growth inhibition and increased apoptosis in primary human keratinocyte cultures and in HET-1A cells. In order to set the doses for a 2-year tumor bioassay, male and female F344 rats were fed fumonisin B1 (99, 163, 234, and 484 ppm) for 28 days and the organs examined histologically. There was a dose dependent decrease in liver and kidney weights in the rats. The liver weight loss was accompanied by the induction of apoptosis and hepatocellular and bile duct hyperplasia in both sexes, with the female rats being more responsive at lower doses. The induction of tubular epithelial cell apoptosis was the primary response of the kidneys to dietary fumonisin B1. Apoptosis was present at all doses in the kidneys of the male rats, and occurred in the females only at 163, 234, and 484 ppm fumonisin B1. These results demonstrate that fumonisin B1 treatment causes a similar increase in apoptosis both in vivo and in vitro.


Assuntos
Apoptose , Carcinógenos Ambientais/farmacologia , Fumonisinas , Rim/citologia , Fígado/citologia , Micotoxinas/farmacologia , Animais , Divisão Celular , Linhagem Celular Transformada , Epitélio , Esôfago , Feminino , Humanos , Masculino , Micotoxinas/administração & dosagem , Ratos , Ratos Endogâmicos F344
16.
Am J Vet Res ; 49(11): 1928-31, 1988 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3247917

RESUMO

Thymus, spleen, adrenal glands, and small intestine of female mice exposed to aerosolized T-2 mycotoxin were examined at postexposure hours (PEH) 0.25, 1, 2, 4, 6, 9, 12, and 24. Lymphocyte necrosis was observed at PEH 1 in the thymus, spleen, and lamina propria and Peyer patches of the small intestine. Necrosis of small intestinal crypt epithelial cells was observed at PEH 2, and necrosis of parenchymal cells and increased number of neutrophils were seen in sinusoids of the adrenal cortex at PEH 4. These results indicated that the earliest microscopic evidence of T-2 mycotoxicosis after aerosol exposure was necrosis of lymphocytes in the thymus, spleen, and lamina propria and Peyer patches of the small intestine.


Assuntos
Glândulas Suprarrenais/patologia , Intestino Delgado/patologia , Sesquiterpenos/toxicidade , Baço/patologia , Toxina T-2/toxicidade , Timo/patologia , Aerossóis , Animais , Feminino , Íleo/patologia , Linfócitos/patologia , Camundongos , Camundongos Endogâmicos ICR , Necrose , Nódulos Linfáticos Agregados/patologia , Toxina T-2/administração & dosagem
17.
Am J Vet Res ; 50(6): 942-4, 1989 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2764347

RESUMO

To evaluate the effect of exogenous testosterone on the development of T-2 toxin-induced necrosis of adrenal glands, mice were allotted to 3 treatment groups. Each treatment group contained castrated male, and castrated and sexually intact female mice. Each mouse in group 1 was given 0.16 mg testosterone propionate at 48-hour intervals for a total of 12 injections, group-2 mice were given similar injections of only the vehicle, and group-3 mice were given no treatment. Twenty-four hours after the last injection, the mice in all 3 groups were exposed for 10 minutes to an aerosol of T-2 toxin. All mice alive at 24 hours after exposure were euthanatized and the adrenal glands and thymuses were examined histologically. Necrosis of the adrenal cortex was not found in any of the mice given preexposure treatment with exogenous testosterone, whereas all mice given vehicle only or no treatment had T-2 toxin-induced necrosis of the inner portion of the adrenal cortex. Lymphocytolysis in the cortex of the thymus confirmed that each mouse of all 3 treatment groups had experienced systemic mycotoxicosis. The uniform severity of the lesion in all mice suggests that the thymus was not protected by exogenous testosterone administration or by the castration status of the mice. We propose that T-2 toxin-induced adrenal necrosis in mice is prevented by the presence of testosterone.


Assuntos
Córtex Suprarrenal/patologia , Sesquiterpenos/toxicidade , Toxina T-2/toxicidade , Testosterona/farmacologia , Animais , Feminino , Masculino , Camundongos , Necrose/prevenção & controle , Necrose/veterinária , Orquiectomia/veterinária , Ovariectomia/veterinária , Toxina T-2/antagonistas & inibidores
18.
Am J Vet Res ; 47(5): 1122-4, 1986 May.
Artigo em Inglês | MEDLINE | ID: mdl-3717737

RESUMO

Experimentally, adrenal cortical parenchymal cell necrosis was induced by T-2 mycotoxin in female, but not male, mice. The lesion occurred in the adrenal glands in 11 of 11 female and 0 of 10 male mice given a nose-only aerosol exposure to T-2 mycotoxin. The necrosis, restricted to the zona fasciculata, began at the X zone interface and extended peripherally to involve 15% to 70% of the zone. Both light and transmission electron microscopies were used to determine whether the cellular and subcellular damage involved parenchymal cells of the zona fasciculata. Extensive necrosis of cortical thymocytes and necrosis of lymphoid cells in follicles of the spleen, lymph nodes, and intestine-associated lymphoid tissue were observed in both sexes. This is the first report to describe adrenal gland necrosis associated with exposure to T-2 mycotoxin.


Assuntos
Doenças do Córtex Suprarrenal/induzido quimicamente , Micotoxinas/toxicidade , Administração Intranasal , Doenças do Córtex Suprarrenal/patologia , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos ICR , Micotoxinas/administração & dosagem , Necrose , Fatores Sexuais , Timo/patologia
19.
Lab Anim ; 30(3): 209-19, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8843045

RESUMO

Ketamine, when used as a mono-anaesthetic, does not appear to induce surgical anaesthesia in the pig. The addition of other drugs such as opioids, benzodiazepines and alpha 2-adrenergic agonists deepens anaesthesia and enables major surgery to be performed. A decision-tree for the rational use of ketamine for both short and long-term anaesthesia in the pig under three different levels of procedure severity is presented.


Assuntos
Anestesia/veterinária , Anestésicos Dissociativos/normas , Ketamina/normas , Suínos/fisiologia , Anestesia/normas , Anestésicos Dissociativos/farmacologia , Animais , Árvores de Decisões , Humanos , Ketamina/farmacologia , Inquéritos e Questionários
20.
J Am Vet Med Assoc ; 185(5): 532-3, 1984 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-6480468

RESUMO

Arteriosclerosis caused by Dirofilaria immitis adult parasites was diagnosed in a 20-month-old Quarter horse stallion that died from cantharidin toxicosis. Microscopically, the pulmonary vascular changes were typical of those described as "proliferative endarteritis" in D immitis-infected dogs.


Assuntos
Arteriosclerose/veterinária , Dirofilariose/veterinária , Doenças dos Cavalos/etiologia , Animais , Arteriosclerose/etiologia , Arteriosclerose/patologia , Dirofilariose/complicações , Dirofilariose/patologia , Doenças dos Cavalos/patologia , Cavalos , Pulmão/patologia , Masculino
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