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1.
BMC Vet Res ; 17(1): 215, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34112165

RESUMO

BACKGROUND: The popularity of new world camelids, particularly alpacas, is growing rapidly in Ireland, presenting a clinical challenge to veterinary practitioners who may not have worked with these species previously. To the authors' knowledge, the clinical course of a case of acute fasciolosis in an alpaca has not previously been reported, and fasciolosis has not been reported at all in alpacas in Ireland, making this case report a valuable addition to the current literature. CASE PRESENTATION: A three-year-old male castrated huacaya alpaca was admitted to UCD Veterinary Hospital with a two-day history of colic and tenesmus. He had been treated with albendazole, dexamethasone and potentiated amoxycillin by the referring veterinary practitioner with no response. On initial clinical exam, sensitivity to abdominal palpation was the only abnormality. However, the alpaca proceeded to show abnormal lying positions, tenesmus and reduced faecal output over the next 24 h. A general blood panel demonstrated moderate anaemia, marked hyperglobulinaemia and moderately increased hepatocellular and hepatobiliary enzyme activity. Abdominal radiography revealed enlargement of the first forestomach compartment without evidence of gastrointestinal obstruction or peritonitis. An abdominal ultrasound exam revealed an elongated, heterogenous mass in the caudoventral abdomen that appeared to be contiguous with the liver. FNA of this mass revealed that it was in fact a liver lobe with biliary stasis and inflammation. Faecal sedimentation demonstrated Fasciola hepatica eggs. In spite of treatment with triclabendazole and supportive treatment including blood transfusion, the alpaca's condition continued to deteriorate and he was euthanised. On post-mortem exam, acute fasciolosis was diagnosed. CONCLUSIONS: The clinical presentation and course of a case of acute fasciolosis in an individual alpaca is described, including the results of a range of diagnostic tests that were carried out. The final diagnosis is supported by a description of post-mortem findings. This information will serve as a resource for veterinary practitioners involved in the diagnosis and treatment of similar cases.


Assuntos
Camelídeos Americanos , Fasciolíase/veterinária , Doença Aguda , Amoxicilina/uso terapêutico , Animais , Antibacterianos/uso terapêutico , Antiplatelmínticos/uso terapêutico , Cólica/parasitologia , Cólica/veterinária , Fasciolíase/diagnóstico , Fasciolíase/tratamento farmacológico , Irlanda , Masculino , Resultado do Tratamento , Triclabendazol/uso terapêutico
2.
Injury ; 46(8): 1625-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25990076

RESUMO

INTRODUCTION: Minimal-invasive placement of screws into the posterior column of the acetabulum (PC) is challenging. Due to the saddle-shaped curvature of the medial cortical border of the PC, the standard fluoroscopic views of the pelvis cannot provide the desired safety during screw insertion. The aim of this study was to define a view tangentially to the medial cortex of the PC and to evaluate its accuracy and inter-observer reproducibility. METHODS: Radio-dense markers on the medial cortex of the PC along the axis of a PC screw were brought in line and landmarks of the new "Down the PC" view were determined. Kirschner wires were placed into the PC of a pelvis composite model and five pelvic cadaver specimens in a total of 34 different correct and incorrect positions. Based on either only the "Down the PC" view, only the standard views, or a combination of both, three fellowship-trained orthopaedic surgeons had to decide if the inserted wires were in bone in the posterior column or had exited cortex, and if they penetrated the acetabulum. Sensitivity, specificity, and the intra-class correlation coefficient were calculated. RESULTS: A view using three radiographic landmarks (pelvic brim, medial cortical wall of the body of the ischium, ischial spine) was found. Sensitivity and specificity to detect perforation out of the bone were 1.00 and 0.97 for the "Down the PC" view, 0.46 and 0.97 if only the standard views were used, and 1.00 and 0.95 for a combination of both. Sensitivity and specificity to detect intra-articular wire placement were 1.00 and 0.96 for the "Down the PC" view, 0.72 and 0.95 if only the standard views were used, and 0.94 and 0.99 for a combination of both. Inter-observer agreement using only the "Down the PC" view was excellent with an ICC of 0.92 for perforation and ICC of 0.82 for intra-articular wire placement. CONCLUSIONS: The "Down the PC" view is a useful addendum in the orthopaedic trauma surgeon's tool box. Using simple landmarks, it is easily to reproduce and thereby shows excellent accuracy and inter-observer agreement in order to detect medial perforation or intra-articular implant position.


Assuntos
Acetábulo/lesões , Fluoroscopia/instrumentação , Fixação Interna de Fraturas/métodos , Fraturas Ósseas/cirurgia , Cirurgia Assistida por Computador/métodos , Parafusos Ósseos , Fraturas Ósseas/patologia , Humanos , Posicionamento do Paciente , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X
3.
Injury ; 46(3): 492-6, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25530407

RESUMO

Femoral neck non union is a relatively uncommon complication following intracapsular hip fracture in the young patient. Almost all patients with femoral neck non union are symptomatic for which they will require some form of revision surgery. This review discusses the role of valgus osteotomy in managing the younger patient with femoral neck non union.


Assuntos
Fraturas do Colo Femoral/complicações , Fraturas não Consolidadas/etiologia , Fraturas não Consolidadas/cirurgia , Osteotomia/métodos , Adolescente , Adulto , Placas Ósseas , Fraturas do Colo Femoral/cirurgia , Consolidação da Fratura , Humanos , Pessoa de Meia-Idade , Resultado do Tratamento
4.
J Orthop Trauma ; 28 Suppl 8: S11-4, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25046410

RESUMO

We conducted a prospective, randomized study on 84 consecutive patients with 88 acute, traumatic femoral shaft fractures using 32 Grosse-Kempf nails, 29 Russell-Taylor nails, and 27 Synthes nails. Although total operative times and proximal and distal locking times were similar for the three groups, the procedure was faster with the Grosse-Kempf nail. Three proximal fractures could not be locked with the Synthes nail. At first follow-up, we found no significant difference in terms of pain, limp, range of motion, or time to union; however, we removed fewer Synthes nails to resolve patient complaints of pain. Three delayed unions were attributed to fracture distraction. We conclude that all three nails are suitable for the treatment of almost all femoral shaft fractures. A careful analysis of intraoperative technique and instrumentation indicates that all three nails can be used safely and easily once experience is gained. Clinical outcome is similar regardless of the nail chosen.


Assuntos
Pinos Ortopédicos/classificação , Fraturas do Fêmur/cirurgia , Fixação Intramedular de Fraturas/instrumentação , Fixação Intramedular de Fraturas/métodos , Adolescente , Adulto , Idoso , Pinos Ortopédicos/efeitos adversos , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Seguimentos , Fixação Intramedular de Fraturas/efeitos adversos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Dor Pós-Operatória/epidemiologia , Estudos Prospectivos , Radiografia , Amplitude de Movimento Articular/fisiologia , Resultado do Tratamento , Adulto Jovem
5.
Injury ; 44(6): 825-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23246562

RESUMO

Patients participating in a modern prospective orthopaedic trauma database may be asked to complete many functional outcome measures, adding to the burden of study participation. This prospective study assessed the utility and responsiveness of the generic Short Form 36 (SF-36) and the disease specific Short Musculoskeletal Function Assessment (SMFA) and the Western Ontario McMaster Osteoarthritis (WOMAC) questionnaires in 55 patients treated operatively for tibial plateau fractures with the goal of determining if there was clear benefit of using multiple measures in a lower extremity peri-articular fracture population. There was very good correlation between all three scores at 6 and 12 months, indicating they are measuring similar factors. Responsiveness was assessed using the standard response mean (SRM), proportion of patients attaining the minimal clinically important difference (MCID) between 6 and 12 months, and floor and ceiling effects. The SRM for the SF-36 was statistically higher than the SRM for the SMFA or the WOMAC. Significantly more patients were found to have a MCID between 6 and 12 months post-surgery based on the SF-36 than the other two functional scores. There was no floor effect found on any of the 3 functional scores evaluated; however, a significant ceiling effect was noted with the WOMAC but not with the SF-36 or the SMFA. These results, along with the usefulness of the SF-36 for comparing disease burden across populations, favour the SF-36 as the instrument of choice in assessing functional outcome in patients with tibial plateau fractures.


Assuntos
Atividades Cotidianas , Fraturas da Tíbia/fisiopatologia , Atividades Cotidianas/psicologia , Adulto , Idoso , Canadá/epidemiologia , Avaliação da Deficiência , Feminino , Indicadores Básicos de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Período Pós-Operatório , Estudos Prospectivos , Psicometria , Índice de Gravidade de Doença , Inquéritos e Questionários , Fraturas da Tíbia/psicologia , Fraturas da Tíbia/cirurgia , Resultado do Tratamento
6.
Food Chem Toxicol ; 50(11): 4097-102, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22906760

RESUMO

The gastrointestinal lumen is directly exposed to dietary contaminants, including patulin, a mycotoxin produced by moulds. Patulin is known to increase permeability across intestinal Caco-2 monolayers. This study aimed to determine the effect of patulin on permeability, ion transport and morphology in isolated rat colonic mucosae. Mucosal sheets were mounted in Ussing chambers and voltage clamped. Apical addition of patulin (100-500 µM) rapidly reduced transepithelial electrical resistance (TEER) and increased permeability to [(14)C] mannitol (2.9-fold). Patulin also inhibited carbachol-induced electrogenic chloride secretion and histological evidence of mucosal damage was observed. To examine potential mechanisms of action of patulin on colonic epithelial cells, high-content analysis of Caco-2 cells was performed and this novel, quantitative fluorescence-based approach confirmed its cytotoxic effects. With regard to time course, the cytotoxicity determined by high content analysis took longer than the almost immediate reduction of electrical resistance in isolated mucosal sheets. These data indicate patulin is not only cytotoxic to enterocytes but also has the capacity to directly alter permeability and ion transport in intact intestinal mucosae. These data corroborate and extend findings in intestinal cell culture monolayers, and further suggest that safety limits on consumption of patulin may be warranted.


Assuntos
Colo/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Patulina/farmacocinética , Patulina/toxicidade , Animais , Células CACO-2/efeitos dos fármacos , Colo/citologia , Relação Dose-Resposta a Droga , Humanos , Técnicas In Vitro , Mucosa Intestinal/metabolismo , Transporte de Íons , Masculino , Manitol/farmacocinética , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Permeabilidade/efeitos dos fármacos , Ratos , Ratos Wistar
7.
J Bone Joint Surg Br ; 94(4): 549-55, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22434474

RESUMO

We performed a systematic review of the literature to evaluate the use and interpretation of generic and disease-specific functional outcome instruments in the reporting of outcome after the surgical treatment of disruptions of the pelvic ring. A total of 28 papers met our inclusion criteria, with eight reporting only generic outcome instruments, 13 reporting only pelvis-specific outcome instruments, and six reporting both. The Short-Form 36 (SF-36) was by far the most commonly used generic outcome instrument, used in 12 papers, with widely variable reporting of scores. The pelvis-specific outcome instruments were used in 19 studies; the Majeed score in ten, Iowa pelvic score in six, Hannover pelvic score in two and the Orlando pelvic score in one. Four sets of authors, all testing construct validity based on correlation with the SF-36, performed psychometric testing of three pelvis-specific instruments (Majeed, IPS and Orlando scores). No testing of responsiveness, content validity, criterion validity, internal consistency or reproducibility was performed. The existing literature in this area is inadequate to inform surgeons or patients in a meaningful way about the functional outcomes of these fractures after fixation.


Assuntos
Avaliação da Deficiência , Fraturas Ósseas/cirurgia , Ossos Pélvicos/lesões , Seguimentos , Fixação de Fratura/reabilitação , Fraturas Ósseas/reabilitação , Indicadores Básicos de Saúde , Humanos , Ossos Pélvicos/cirurgia , Psicometria , Recuperação de Função Fisiológica , Resultado do Tratamento
8.
Anaesthesia ; 66(5): 341-7, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21418045

RESUMO

We investigated the effect of epidural volume extension on spinal blockade in pregnant women undergoing elective caesarean section with a combined spinal-epidural technique. We randomly allocated 90 healthy subjects to three groups to receive spinal hyperbaric bupivacaine 7.5 mg (group B7.5), spinal hyperbaric bupivacaine 7.5 mg immediately followed by epidural volume extension with saline 5 ml (group B7.5-EVE) or spinal hyperbaric bupivacaine 10 mg without epidural volume extension (group B10). We evaluated the height of the block every 5 min for 15 min following the spinal injection. The overall sensory block level increased with time (p < 0.001), regardless of the group studied, and there were significantly fewer failures of block in the group B10 compared with both B7.5 and B7.5-EVE groups (p = 0.001). In conclusion, we could not demonstrate a benefit in using epidural volume extension with 5 ml saline as part of a combined spinal epidural technique in term parturients undergoing elective caesarean section.


Assuntos
Anestesia Epidural/métodos , Anestesia Obstétrica/métodos , Raquianestesia/métodos , Cesárea , Adulto , Anestesia Epidural/efeitos adversos , Anestesia Obstétrica/efeitos adversos , Raquianestesia/efeitos adversos , Anestésicos Locais/administração & dosagem , Anestésicos Locais/efeitos adversos , Índice de Apgar , Bupivacaína/administração & dosagem , Bupivacaína/efeitos adversos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Movimento/efeitos dos fármacos , Gravidez , Estudos Prospectivos , Sensação/efeitos dos fármacos , Cloreto de Sódio/administração & dosagem
10.
Toxicol In Vitro ; 24(8): 2063-71, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20670680

RESUMO

Using high content analysis (HCA), we assessed whether cytotoxicity biomarkers translate from in vitro to in vivo models using four anti-cancer drugs (arabinoside C, arsenic trioxide, doxorubicin, and mitoxantrone) and staining live cells with Hoechst 33342 for DNA (nuclear area, nuclear intensity and cell number), Fluo-4 for ionised calcium, TMRM for mitochondrial membrane potential and TOTO-3 for plasma membrane permeability. Human HepG2 hepatocytes and Jurkat T-lymphocytes were treated with 10-fold increasing concentrations of drug for 24 and 72 h. We demonstrate that HCA can be carried out on suspension cells and that this in vivo model was at least as sensitive as the in vitro model. In addition, we show that the concentration of DOX in the nucleus and its anti-cancer mechanism of action can be assessed due to its intrinsic fluorescence and its DNA intercalation in competition with the Hoechst dye. We conclude cytotoxicity biomarkers translate from the in vitro, predictive, hepatocyte model to the in vivo lymphocyte model. Thus, HCA cytotoxicity biomarkers may not only be predictive of human toxicity potential but may be translatable for detection and monitoring of subclinical toxicity.


Assuntos
Antineoplásicos/toxicidade , Biomarcadores/metabolismo , Citotoxinas/toxicidade , Modelos Biológicos , Testes de Toxicidade/métodos , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Bioensaio/métodos , Relação Dose-Resposta a Droga , Doxorrubicina/toxicidade , Células Hep G2 , Humanos , Células Jurkat
11.
Orthop Traumatol Surg Res ; 96(5): 579-82, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20663733

RESUMO

The use of tension band wire technique for patella fractures fixation is a well-established technique. However, the standard technique, which involves using two Kirschner wires through the patella, can cause problems with prominent hardware, and difficulty capturing the change to figure of eight wire. Here we describe a modified technique using four Kirschner wires, which allows each wire to be bent, and well-impacted in order to avoid these problems. The basic surgical technique, and our case series are reviewed.


Assuntos
Fios Ortopédicos , Fixação Interna de Fraturas/métodos , Fraturas Ósseas/cirurgia , Patela/lesões , Parafusos Ósseos , Remoção de Dispositivo , Fraturas não Consolidadas/cirurgia , Humanos , Complicações Pós-Operatórias/cirurgia , Reoperação
13.
J Orthop Trauma ; 23(9): 615-21, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19897981

RESUMO

OBJECTIVES: To determine if there is a difference in morbidity and mortality in orthopaedic trauma patients with femoral shaft fractures undergoing early definitive care with intramedullary (IM) nails in the supine versus the lateral position. DESIGN: Retrospective cohort study, single centered. SETTING: One level 1 trauma center. PATIENTS: Nine hundred eighty-eight patients representing 1027 femoral shaft fractures treated with IM nails were identified through a prospectively gathered database between 1987 and 2006. INTERVENTION: Antegrade IM nail insertion with reaming of the femoral canal in either the supine or lateral position. OUTCOME MEASURES: Mortality was the primary outcome. Admission to intensive care unit (ICU) was the secondary outcome measure and a surrogate measure of morbidity. Literature review was performed to identify factors shown to contribute to morbidity and mortality in orthopaedic trauma patients. Intraoperative position in either the supine or lateral position was added to this list. Logistic regression analysis was performed to determine the magnitude and effect of the independent variables on each of the study end points. To determine if a more significant trend toward less favorable outcomes was observed with increasing severity of injury, particularly injuries of the chest and thorax, subgroup analysis was performed for all those with a femur fracture and an Injury Severity Score > or =18 and all those with a femur fracture and an Abbreviated Injury Score chest > or =3. RESULTS: Intraoperative position in either the supine or lateral position was not a significant predictor of mortality or ICU admission for the original cohort or the subgroup of Injury Severity Score > or =18. However, for the subgroup of Abbreviated Injury Score chest > or =3, intraoperative positioning in the lateral position had a statistically significant protective effect against ICU admission (P = 0.044). CONCLUSIONS: For polytrauma patients with femoral shaft fractures, surgical stabilization using IM nails inserted with reaming of the femoral canal in the lateral position is not associated with an increased risk of mortality or ICU admission.


Assuntos
Fraturas do Fêmur/cirurgia , Fixação Intramedular de Fraturas/métodos , Cuidados Intraoperatórios , Adulto , Idoso , Idoso de 80 Anos ou mais , Pinos Ortopédicos , Colúmbia Britânica/epidemiologia , Estudos de Coortes , Feminino , Fraturas do Fêmur/mortalidade , Fraturas do Fêmur/fisiopatologia , Fixação Intramedular de Fraturas/instrumentação , Humanos , Unidades de Terapia Intensiva , Período Intraoperatório , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Decúbito Dorsal , Taxa de Sobrevida , Centros de Traumatologia , Índices de Gravidade do Trauma , Adulto Jovem
14.
Arch Physiol Biochem ; 115(2): 105-11, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19485706

RESUMO

Insulin resistance and hepatotoxicity induced in high fructose fed rats may involve fructose derived endogenous toxins formed by inflammation. Thus fructose was seventy-fold more toxic if hepatocytes were exposed to non-toxic levels of hydrogen peroxide (H(2)O(2)) released by inflammatory cells. This was prevented by iron (Fe) chelators, hydroxyl radical scavengers, and increased by Fe, copper (Cu) or catalase inhibition. Fructose or glyceraldehyde/dihydroxyacetone metabolites were oxidized by Fenton radicals to glyoxal. Glyoxal (15 microM) cytotoxicity was increased about 200-fold by H(2)O(2). Glycolaldehyde was enzymically formed from glyceraldehyde, the fructokinase/aldolase B product of fructose. Glycolaldehyde cytotoxicity was increased 20-fold by H(2)O(2). The oxidative stress cytotoxicity induced was attributed to the Fenton oxidation of glycolaldehyde forming glycolaldehyde radicals and glyoxal, since cytotoxicity was prevented by aminoguanidine (glyoxal trap) or Fenton inhibitors. Glyoxal was also the Fenton product responsible for glycolaldehyde protein carbonylation as carbonylation was prevented by aminoguanidine or Fenton inhibitors.


Assuntos
Acetaldeído/análogos & derivados , Frutose/metabolismo , Hepatócitos/metabolismo , Inflamação/metabolismo , Toxinas Biológicas/metabolismo , Acetaldeído/toxicidade , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Antioxidantes/toxicidade , Relação Dose-Resposta a Droga , Glioxal/metabolismo , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/toxicidade , Masculino , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Carbonilação Proteica/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Pesquisa , Fatores de Tempo
15.
Chem Biol Interact ; 180(1): 79-88, 2009 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-19428347

RESUMO

Diallyl disulfide (DADS) and diallyl sulfide (DAS) are the major metabolites found in garlic oil and have been reported to lower cholesterol and prevent cancer. The molecular cytotoxic mechanisms of DADS and DAS have not been determined. The cytotoxic effectiveness of hydrogen versus allyl sulfides towards hepatocytes was found to be as follows: NaHS>DADS>DAS. Hepatocyte mitochondrial membrane potential was decreased and reactive oxygen species (ROS) and TBARS formation was increased by all three allyl sulfides. (1) DADS induced cytotoxicity was prevented by the H(2)S scavenger hydroxocobalamin, which also prevented cytochrome oxidase dependent mitochondrial respiration suggesting that H(2)S inhibition of cytochrome oxidase contributed to DADS hepatocyte cytotoxicity. (2) DAS cytotoxicity on the other hand was prevented by hydralazine, an acrolein trap. Hydralazine also prevented DAS induced GSH depletion, decreased mitochondrial membrane potential and increased ROS and TBARS formation. Chloral hydrate, the aldehyde dehydrogenase 2 inhibitor, however had the opposite effects, which could suggest that acrolein contributed to DAS hepatocyte cytotoxicity.


Assuntos
Compostos Alílicos/toxicidade , Anticarcinógenos/toxicidade , Dissulfetos/toxicidade , Hepatócitos/efeitos dos fármacos , Sulfetos/toxicidade , Animais , Sobrevivência Celular , Células Cultivadas , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/análise , Substâncias Reativas com Ácido Tiobarbitúrico/análise
16.
Chem Biol Interact ; 178(1-3): 332-9, 2009 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-19000661

RESUMO

Dietary fructose consumption is one of the environmental factors contributing to the development of obesity and a fatty liver (hepatic steatosis). A two-hit hypothesis has been proposed for progression of hepatic steatosis to the more serious non-alcoholic steatosis (NASH), with the first hit being hepatic steatosis, and the second hit being inflammation and associated oxidative stress caused by reactive oxygen species (ROS) formation. As well, fructose-fed rats develop insulin resistance and serum levels of methylglyoxal, a glycolytic metabolite, are increased. Previously we reported that glyoxal-induced hepatocyte cytotoxicity could be attributed to mitochondrial toxicity as mitochondrial membrane potential was decreased and cytotoxicity was increased several orders of magnitude by low non-cytotoxic doses of H(2)O(2) (hepatocyte inflammation model). In this study, we have assessed the toxicity of fructose towards hepatocytes and investigated the molecular cytotoxic mechanisms involved. Fructose itself was only toxic at 1.5M, whereas 12 mM caused 50% cell death in 2h if the hepatocytes were exposed to a non-cytotoxic dose of H(2)O(2) continuously generated by glucose and glucose oxidase. The cytotoxic mechanism involved oxidative stress as ROS and H(2)O(2) formation preceded cytotoxicity, and cytotoxicity was prevented by radical scavengers, lipid antioxidants and ROS scavengers. It is proposed that the highly potent Fenton derived ROS catalyse the oxidation of fructose and particularly its carbonyl metabolites glycolaldehyde, dihydroxyacetone, glyceraldehyde. The carbon radicals and glyoxal formed compromise the cell's resistance to H(2)O(2).


Assuntos
Frutose/metabolismo , Animais , Fluoretos/farmacologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Masculino , Metais/toxicidade , Ratos , Ratos Sprague-Dawley
17.
Vet Clin Pathol ; 36(4): 325-30, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18041696

RESUMO

After 5 years of development, the European College of Veterinary Clinical Pathology (ECVCP) was formally recognized and approved on July 4, 2007 by the European Board of Veterinary Specialisation (EBVS), the European regulatory body that oversees specialization in veterinary medicine and which has approved 23 colleges. The objectives, committees, basis for membership, constitution, bylaws, information brochure and certifying examination of the ECVCP have remained unchanged during this time except as directed by EBVS. The ECVCP declared full functionality based on the following criteria: 1) a critical mass of 65 members: 15 original diplomates approved by the EBVS to establish the ECVCP, 37 de facto diplomates, 7 diplomates certified by examination, and 5 elected honorary members; 2) the development and certification of training programs, laboratories, and qualified supervisors for residents; currently there are 18 resident training programs in Europe; 3) administration of 3 annual board-certifying examinations thus far, with an overall pass rate of 70%; 4) European consensus criteria for assessing the continuing education of specialists every 5 years; 5) organization of 8 annual scientific congresses and a joint journal (with the American Society for Veterinary Clinical Pathology) for communication of scientific research and information; the College also maintains a website, a joint listserv, and a newsletter; 6) collaboration in training and continuing education with relevant colleges in medicine and pathology; 7) development and strict adherence to a constitution and bylaws compliant with the EBVS; and 8) demonstration of compelling rationale, supporting data, and the support of members and other colleges for independence as a specialty college. Formal EBVS recognition of ECVCP as the regulatory body for the science and practice of veterinary clinical pathology in Europe will facilitate growth and development of the discipline and compliance of academic, commercial diagnostic, and industry laboratories in veterinary clinical pathology. Future needs are in developing sponsorship for resident positions, increasing employment opportunities, increasing compliance with laboratory, training, and continuing education standards, and advancing relevant science and technology.


Assuntos
Educação em Veterinária/tendências , Patologia Clínica/organização & administração , Sociedades/organização & administração , Medicina Veterinária/organização & administração , Europa (Continente)
18.
SAR QSAR Environ Res ; 17(4): 413-28, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16920662

RESUMO

Although the literature is replete with QSAR models developed for many toxic effects caused by reversible chemical interactions, the development of QSARs for the toxic effects of reactive chemicals lacks a consistent approach. While limitations exit, an appropriate starting-point for modeling reactive toxicity is the applicability of the general rules of organic chemical reactions and the association of these reactions to cellular targets of importance in toxicology. The identification of plausible "molecular initiating events" based on covalent reactions with nucleophiles in proteins and DNA provides the unifying concept for a framework for reactive toxicity. This paper outlines the proposed framework for reactive toxicity. Empirical measures of the chemical reactivity of xenobiotics with a model nucleophile (thiol) are used to simulate the relative rates at which a reactive chemical is likely to bind irreversibly to cellular targets. These measures of intrinsic reactivity serve as correlates to a variety of toxic effects; what's more they appear to be more appropriate endpoints for QSAR modeling than the toxicity endpoints themselves.


Assuntos
Biologia Computacional/métodos , Relação Quantitativa Estrutura-Atividade , Toxicologia/métodos , Xenobióticos/química , Xenobióticos/toxicidade , Aminoácidos/química , Animais , Sítios de Ligação , Simulação por Computador , Hepatócitos/efeitos dos fármacos , Modelos Químicos , Ácidos Nucleicos/química , Sistema Respiratório/efeitos dos fármacos , Pele/efeitos dos fármacos , Compostos de Sulfidrila/química , Tetrahymena pyriformis/efeitos dos fármacos
19.
Lab Anim ; 40(2): 153-71, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16600075

RESUMO

This study directly demonstrates that cardiac troponin I (cTnI) is a sensitive, specific, and persistent biomarker in laboratory animals. Histopathological and pathophysiological cardiac changes in dogs, rats and mice correlated with increased serum cTnI with various cardiac inotropic agents, and cardiotoxic drugs and with cardiac arrhythmias, tachycardia, cardiac effusion with dyspnoea, and ageing. A comparison of six immunoassays for cTnI and cardiac troponin T (cTnT) to detect and monitor cardiac injury in a rodent model indicated that enzyme-linked immunosorbent (Life Diagnostics Inc and TriChem Resources Inc, West Chester, Philadelphia, USA) and Immulite (Diagnostic Products Corporation, Llanberis, UK) assays had low sensitivity and less than 1% of the dynamic range of Centaur (Bayer Healthcare Diagnostics, Newbury, UK) cTnI and Elecsys (Roche Diagnostics, Basel, Switzerland) and M8 (Bioveris Europe, Whitney, UK) cTnT assays. In dogs, however, the Immulite assay was effective and correlated with the Centaur. Serum concentrations were highly correlated but 10-fold lower for cTnT compared with cTnI with cardiac injury. Centaur assay also detected cTnI in myocardium from marmosets, swine, cattle, and guinea pigs, indicating it to be candidate cardiac biomarker for these species as well. Purified rat cTnI was 50% more reactive than purified human cTnI in the Centaur assay. In the rat, an age- and gender-dependent variation in serum cTnI was found. Male rats aged six and eight months had a 10-fold greater serum cTnI than age-matched females and three-month-old rats. These increases correlated with minimal histopathological change. Isoproterenol-induced serum cTnI increased up to 760-fold the minimal detectable concentration of 0.07 microg/L, within 4-6 h and decreased with a half-life of 6 h, with an expected return to baseline of 60 h. Severity of histopathological change correlated with serum cTnI during the ongoing injury.


Assuntos
Doenças dos Animais/sangue , Animais de Laboratório/sangue , Cardiopatias/veterinária , Medições Luminescentes/veterinária , Troponina I/sangue , Doenças dos Animais/diagnóstico , Animais , Biomarcadores/sangue , Cães , Feminino , Cardiopatias/sangue , Medições Luminescentes/normas , Masculino , Camundongos , Miocárdio/química , Ratos , Sensibilidade e Especificidade , Troponina T/sangue
20.
Arch Toxicol ; 80(9): 580-604, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16598496

RESUMO

To develop and validate a practical, in vitro, cell-based model to assess human hepatotoxicity potential of drugs, we used the new technology of high content screening (HCS) and a novel combination of critical model features, including (1) use of live, human hepatocytes with drug metabolism capability, (2) preincubation of cells for 3 days with drugs at a range of concentrations up to at least 30 times the efficacious concentration or 100 microM, (3) measurement of multiple parameters that were (4) morphological and biochemical, (5) indicative of prelethal cytotoxic effects, (6) representative of different mechanisms of toxicity, (7) at the single cell level and (8) amenable to rapid throughput. HCS is based on automated epifluorescence microscopy and image analysis of cells in a microtiter plate format. The assay was applied to HepG2 human hepatocytes cultured in 96-well plates and loaded with four fluorescent dyes for: calcium (Fluo-4 AM), mitochondrial membrane potential (TMRM), DNA content (Hoechst 33,342) to determine nuclear area and cell number and plasma membrane permeability (TOTO-3). Assay results were compared with those from 7 conventional, in vitro cytotoxicity assays that were applied to 611 compounds and shown to have low sensitivity (<25%), although high specificity ( approximately 90%) for detection of toxic drugs. For 243 drugs with varying degrees of toxicity, the HCS, sublethal, cytotoxicity assay had a sensitivity of 93% and specificity of 98%. Drugs testing positive that did not cause hepatotoxicity produced other serious, human organ toxicities. For 201 positive assay results, 86% drugs affected cell number, 70% affected nuclear area and mitochondrial membrane potential and 45% affected membrane permeability and 41% intracellular calcium concentration. Cell number was the first parameter affected for 56% of these drugs, nuclear area for 34% and mitochondrial membrane potential for 29% and membrane permeability for 7% and intracellular calcium for 10%. Hormesis occurred for 48% of all drugs with positive response, for 26% of mitochondrial and 34% nuclear area changes and 12% of cell number changes. Pattern of change was dependent on the class of drug and mechanism of toxicity. The ratio of concentrations for in vitro cytotoxicity to maximal efficaciousness in humans was not different across groups (12+/-22). Human toxicity potential was detected with 80% sensitivity and 90% specificity at a concentration of 30x the maximal efficacious concentration or 100 microM when efficaciousness was not considered. We conclude that human hepatotoxicity is highly concordant with in vitro cytotoxicity in this novel model and as detected by HCS.


Assuntos
Alternativas aos Testes com Animais , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Hepatócitos/efeitos dos fármacos , Testes de Toxicidade/métodos , Xenobióticos/toxicidade , Cálcio/metabolismo , Carcinoma Hepatocelular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Concentração Inibidora 50 , Neoplasias Hepáticas , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Xenobióticos/classificação
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