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1.
Neurogenetics ; 18(2): 73-79, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27747449

RESUMO

Kinesins play a critical role in the organization and dynamics of the microtubule cytoskeleton, making them central players in neuronal proliferation, neuronal migration, and postmigrational development. Recently, KIF2A mutations were identified in cortical malformation syndromes associated with microcephaly. Here, we detected two de novo p.Ser317Asn and p.His321Pro mutations in KIF2A in two patients with lissencephaly and microcephaly. In parallel, we re-evaluated the two previously reported cases showing de novo mutations of the same residues. The identification of mutations only in the residues Ser317 and His321 suggests these are hotspots for de novo mutations. Both mutations lead to a classic form of lissencephaly, with a posterior to anterior gradient, almost indistinguishable from LIS1-related lissencephaly. However, three fourths of patients also showed variable congenital and postnatal microcephaly, up to -5 SD. Located in the motor domain of the KIF2A protein, the Ser317 and His321 alterations are expected to disrupt binding or hydrolysis of ATP and consequently the MT depolymerizing activity. This report also establishes that KIF2A mutations represent significant causes of classic lissencephaly with microcephaly.


Assuntos
Lissencefalias Clássicas e Heterotopias Subcorticais em Banda/genética , Cinesinas/genética , Mutação de Sentido Incorreto , Adolescente , Análise Mutacional de DNA , Feminino , Frequência do Gene , Humanos , Lactente , Lisencefalia/genética , Masculino , Polimorfismo de Nucleotídeo Único
2.
Dis Aquat Organ ; 127(1): 49-56, 2017 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-29256427

RESUMO

Harbour porpoises are often found to be infected by endoparasites in several organs including the lungs and stomach as well as the heart, liver and ears. Nevertheless there is still little knowledge about the impact, ecology, transmission, and virulence of these parasitic infections. Here, we profile the presence of parasites in 4 frequently infected organs (lungs, stomach, liver and ears) in relation to biological parameters of harbour porpoises stranded along the Dutch coastline between December 2008 and December 2013. We found that parasites were common, with prevalence of 68% in lungs, 74.4% in ears, 26% in stomach and 23.5% in liver. We used generalised linear models to further quantify parasite presence in relation to biological data gathered during necropsy (sex, body length and nutritive condition). Body length (used as a proxy for age) was significant in explaining parasite presence for all organs with increasing probability of having the parasite with increasing body length. For the parasitic infections in the ears and stomach the nutritive condition was an additional significant factor, with a higher probability of parasite presence in porpoises in a poorer nutritive condition. The results of this study can be used as a baseline for assessing parasite presence in harbour porpoises and are a first step towards linking parasite infections to basic biological data gathered during necropsy.


Assuntos
Doenças Parasitárias em Animais/parasitologia , Phocoena/parasitologia , Animais , Otopatias/parasitologia , Otopatias/veterinária , Hepatopatias/parasitologia , Hepatopatias/veterinária , Pneumopatias Parasitárias/veterinária , Países Baixos , Doenças Parasitárias em Animais/patologia , Gastropatias/parasitologia , Gastropatias/veterinária
3.
Klin Monbl Augenheilkd ; 231(12): 1187-95, 2014 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-25519506

RESUMO

This review documents technical progress in ophthalmic magnetic resonance imaging (MRI) at ultrahigh fields (UHF, B(0) ≥ 7.0 T). The review surveys frontier applications of UHF-MRI tailored for high spatial resolution in vivo imaging of the eye, orbit and optic nerve. Early examples of clinical ophthalmic UHF-MRI including the assessment of melanoma of the choroid membrane and the characterisation of intraocular masses are demonstrated. A concluding section ventures a glance beyond the horizon and explores research promises along with future directions of ophthalmic UHF-MRI.


Assuntos
Neoplasias Oculares/patologia , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Oftalmoscopia/métodos , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Avaliação da Tecnologia Biomédica
4.
Hum Mol Genet ; 20(8): 1536-46, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21262862

RESUMO

Cranial neural tube defects (NTDs) occur in mice carrying mutant alleles of many different genes, whereas isolated spinal NTDs (spina bifida) occur in fewer models, despite being common human birth defects. Spina bifida occurs at high frequency in the Axial defects (Axd) mouse mutant but the causative gene is not known. In the current study, the Axd mutation was mapped by linkage analysis. Within the critical genomic region, sequencing did not reveal a coding mutation whereas expression analysis demonstrated significant up-regulation of grainyhead-like 2 (Grhl2) in Axd mutant embryos. Expression of other candidate genes did not differ between genotypes. In order to test the hypothesis that over-expression of Grhl2 causes Axd NTDs, we performed a genetic cross to reduce Grhl2 function in Axd heterozygotes. Grhl2 loss of function mutant mice were generated and displayed both cranial and spinal NTDs. Compound heterozygotes carrying both loss (Grhl2 null) and putative gain of function (Axd) alleles exhibited normalization of spinal neural tube closure compared with Axd/+ littermates, which exhibit delayed closure. Grhl2 is expressed in the surface ectoderm and hindgut endoderm in the spinal region, overlapping with grainyhead-like 3 (Grhl3). Axd mutants display delayed eyelid closure, as reported in Grhl3 null embryos. Moreover, Axd mutant embryos exhibited increased ventral curvature of the spinal region and reduced proliferation in the hindgut, reminiscent of curly tail embryos, which carry a hypomorphic allele of Grhl3. Overall, our data suggest that defects in Axd mutant embryos result from over-expression of Grhl2.


Assuntos
Disrafismo Espinal/genética , Fatores de Transcrição/genética , Animais , Proliferação de Células , Mapeamento Cromossômico , Cromossomos de Mamíferos/genética , Feminino , Inativação Gênica , Ligação Genética , Humanos , Hibridização Genética , Trato Gastrointestinal Inferior/anormalidades , Trato Gastrointestinal Inferior/citologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Mutação , Disrafismo Espinal/embriologia , Fatores de Transcrição/metabolismo , Transcrição Gênica , Regulação para Cima
5.
Virol J ; 10: 276, 2013 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-24007444

RESUMO

BACKGROUND: Highly pathogenic avian influenza (HPAI) viruses pose a potential human health threat as they can be transmitted directly from infected poultry to humans. During a large outbreak of HPAI H7N7 virus among poultry in The Netherlands in 2003, bird to human transmission was confirmed in 89 cases, of which one had a fatal outcome. METHODS: To identify genetic determinants of virulence in a mammalian host, we passaged an avian H7N7/03 outbreak isolate in mouse lungs and evaluated the phenotype of the mouse-adapted variant in animal models and in vitro. RESULTS: Three passages in mouse lungs were sufficient to select a variant that was highly virulent in mice. The virus had a MLD50 that was >4.3 logs lower than that of its non-lethal parental virus. Sequence analysis revealed a single mutation at position 627 in PB2, where the glutamic acid was changed to a lysine (E627K). The mouse-adapted virus has this mutation in common with the fatal human case isolate. The virus remained highly pathogenic for chickens after its passage in mice. In ferrets, the mouse-adapted virus induced more severe disease, replicated to higher titers in the lower respiratory tract and spread more efficiently to systemic organs compared with the parental virus. In vitro, the PB2 E627K mutation had a promoting effect on virus propagation in mammalian, but not in avian cells. CONCLUSIONS: Our results show that the E627K mutation in PB2 alone can be sufficient to convert an HPAI H7N7 virus of low virulence to a variant causing severe disease in mice and ferrets. The rapid emergence of the PB2 E627K mutant during mouse adaptation and its pathogenicity in ferrets emphasize the potential risk of HPAI H7N7 viruses for human health.


Assuntos
Adaptação Biológica , Vírus da Influenza A Subtipo H7N7/genética , Vírus da Influenza A Subtipo H7N7/isolamento & purificação , Mutação de Sentido Incorreto , RNA Polimerase Dependente de RNA/genética , Proteínas Virais/genética , Estruturas Animais/patologia , Estruturas Animais/virologia , Animais , Galinhas , Modelos Animais de Doenças , Feminino , Furões , Influenza Aviária/virologia , Dose Letal Mediana , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Análise de Sobrevida , Virulência
6.
Int J Legal Med ; 127(1): 85-91, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22673800

RESUMO

The smoking cessation agent varenicline acts as a partial agonist on α(4)ß(2) nicotinic acetylcholine receptors. Although debated, several reports have linked varenicline therapy to an increased risk of suicidal thoughts and/or suicide. In addition, several non-fatal overdose cases have been reported. In this report, we utilised a sample preparation procedure suitable for postmortem samples and gas chromatography coupled to mass spectrometry to analyse samples obtained from a suicidal case in which ingestion of an overdose of varenicline had occurred. Extremely high concentrations of varenicline (>250 ng/ml) were detected in the blood of the deceased, in addition to high concentrations in urine and vitreous humour. To the best of our knowledge, similar high concentrations have not been reported yet. Although, with respect to the mechanism of death in this case, confounding factors were concomitant ethanol consumption and, importantly, potentially fatal hypothermia, this is the first report of a fatality associated with the ingestion of an overdose of varenicline.


Assuntos
Benzazepinas/intoxicação , Overdose de Drogas , Agonistas Nicotínicos/intoxicação , Quinoxalinas/intoxicação , Suicídio , Adulto , Benzazepinas/análise , Depressores do Sistema Nervoso Central/análise , Etanol/análise , Toxicologia Forense , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Hipotermia/patologia , Masculino , Agonistas Nicotínicos/análise , Quinoxalinas/análise , Vareniclina , Corpo Vítreo/química
7.
Hum Mutat ; 33(3): 561-71, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22213089

RESUMO

Ataxia-telangiectasia (A-T) is an autosomal recessive neurodegenerative disorder with multisystem involvement and cancer predisposition, caused by mutations in the A-T mutated (ATM) gene. To study genotype-phenotype correlations, we evaluated the clinical and laboratory data of 51 genetically proven A-T patients, and additionally measured ATM protein expression and kinase activity. Patients without ATM kinase activity showed the classical phenotype. The presence of ATM protein, correlated with slightly better immunological function. Residual kinase activity correlated with a milder and essentially different neurological phenotype, absence of telangiectasia, normal endocrine and pulmonary function, normal immunoglobulins, significantly lower X-ray hypersensitivity in lymphocytes, and extended lifespan. In these patients, cancer occurred later in life and generally consisted of solid instead of lymphoid malignancies. The genotypes of severely affected patients generally included truncating mutations resulting in total absence of ATM kinase activity, while patients with milder phenotypes harbored at least one missense or splice site mutation resulting in expression of ATM with some kinase activity. Overall, the phenotypic manifestations in A-T show a continuous spectrum from severe classical childhood-onset A-T to a relatively mild adult-onset disorder, depending on the presence of ATM protein and kinase activity. Each patient is left with a tremendously increased cancer risk.


Assuntos
Ataxia Telangiectasia/metabolismo , Ataxia Telangiectasia/patologia , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Adolescente , Adulto , Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia , Proteínas de Ciclo Celular/genética , Criança , Proteínas de Ligação a DNA/genética , Feminino , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Serina-Treonina Quinases/genética , Proteínas Supressoras de Tumor/genética , Adulto Jovem
9.
Free Radic Biol Med ; 192: 152-164, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36152914

RESUMO

Histones are critical for the packaging of nuclear DNA and chromatin assembly, which is facilitated by the high abundance of Lys and Arg residues within these proteins. These residues are also the site of a range of post-translational modifications, which influence the regulatory function of histones. Histones are also present in the extracellular environment, following release by various pathways, particularly neutrophil extracellular traps (NETs). NETs contain myeloperoxidase, which retains its enzymatic activity and produces hypochlorous acid (HOCl). This suggests that histones could be targets for HOCl under conditions where aberrant NET release is prevalent, such as chronic inflammation. In this study, we examine the reactivity of HOCl with a mixture of linker (H1) and core (H2A, H2B, H3 and H4) histones. HOCl modified the histones in a dose- and time-dependent manner, resulting in structural changes to the proteins and the formation of a range of post-translational modification products. N-Chloramines are major products following exposure of the histones to HOCl and decompose over 24 h forming Lys nitriles and carbonyls (aminoadipic semialdehydes). Chlorination and dichlorination of Tyr, but not Trp residues, is also observed. Met sulfoxide and Met sulfones are formed, though these oxidation products are also detected albeit at a lower extent, in the non-treated histones. Evidence for histone fragmentation and aggregation was also obtained. These results could have implications for the development of chronic inflammatory diseases, given the key role of Lys residues in regulating histone function.


Assuntos
Ácido Hipocloroso , Oxidantes , Cloraminas/metabolismo , DNA , Histonas , Ácido Hipocloroso/metabolismo , Nitrilas , Peroxidase/metabolismo , Sulfonas , Sulfóxidos
10.
Int J Legal Med ; 125(3): 333-40, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-20396898

RESUMO

The determination of the survival time after a crime as well as the concomitant physical and mental load of the victim is an important task for the forensic pathologist. The heat shock protein, ubiquitin, exerts an essential role in the cellular response to stress. We aimed to investigate the usefulness of the ubiquitin expression in the locus coeruleus as a marker for the evaluation of agonal stress. Is the amount of ubiquitin in this brain locus an indication of the length and/or intensity of the agonal period following various causes of death? The immunohistochemical (IHC) expression of ubiquitin is examined in formalin-fixed, paraffin-embedded slides of the human locus coeruleus (n = 48). The evaluation of the IHC staining is blindly performed, prior to the study of the medico-legal files. According to the length of agony, a division into subgroups is made. Three possible IHC staining patterns are observed: a staining of the neuronal nucleus or the cytoplasm or both. In addition, the number of neurons with ubiquitin expression per µm(2) is calculated in each locus coeruleus. Significant differences in the number of ubiquitin-immunoreactive neurons are noticed with respect to the length of the agony: A higher density of positive neurons is seen in case of a pronounced and extended death struggle.


Assuntos
Morte , Locus Cerúleo/metabolismo , Estresse Fisiológico , Ubiquitina/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Criança , Pré-Escolar , Medicina Legal , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Neurônios/metabolismo , Neurônios/patologia , Ubiquitina/ultraestrutura , Adulto Jovem
11.
J Vasc Res ; 46(5): 459-68, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19204403

RESUMO

Vascular changes in diabetes are characterized by reduced vasoconstriction and vascular remodeling. Previously, we demonstrated that TGF-beta1 impairs Ang II-induced contraction through reduced calcium mobilization. However, the effect of TGF-beta1 on Ang II-induced vascular remodeling is unknown. Therefore, we investigated the effect of TGF-beta1 on Ang II-induced activation of the MAPK p44/42 pathway in cultured rat aortic smooth muscle cells (RASMC). Activation of MAPK p44/42 was determined with a phospho-specific antibody. Angiotensin type 1 receptor (AT(1)) and AT(1) mRNA levels were measured by [(3)H]candesartan-binding and real-time PCR, respectively. AT(1) gene transcription activity was assessed using AT(1) promoter-reporter constructs and by a nuclear runoff assay. In TGF-beta1-pretreated cells, Ang II-induced phosphorylation of MAPK p44/42 was inhibited by 29 and 46% for p42 and p44, respectively, and AT(1) density was reduced by 31%. Furthermore, pretreatment with TGF-beta1 resulted in a 64% reduction in AT(1) mRNA levels and decreased AT(1) mRNA transcription rate by 42%. Pretreatment with TGF-beta1 blocked Ang II-induced proliferation of RASMC, while stimulating Ang II-induced upregulation of plasminogen activator inhibitor-1. In conclusion, TGF-beta1 attenuates Ang II-mediated MAPK p44/42 kinase signaling in RASMC through downregulation of AT(1) levels, which is mainly caused by the inhibition of transcription of the AT(1) gene.


Assuntos
Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Músculo Liso Vascular/enzimologia , Receptor Tipo 1 de Angiotensina/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Angiotensina II/farmacologia , Animais , Aorta/citologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Células Cultivadas , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia , Estabilidade de RNA/efeitos dos fármacos , Estabilidade de RNA/fisiologia , RNA Mensageiro/metabolismo , Ratos , Receptor Tipo 1 de Angiotensina/genética , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/fisiologia , Fator de Crescimento Transformador beta1/farmacologia , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasoconstritores/farmacologia
12.
Int J Legal Med ; 123(6): 451-8, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18839201

RESUMO

A gas chromatographic-mass spectrometric (GC-MS) method in positive ion chemical ionization mode in combination with a solid phase extraction was optimized for new-generation antidepressants and their metabolites in postmortem blood, brain tissue, and hair. Twelve antidepressants and their active metabolites (i.e., mirtazapine, viloxazine, venlafaxine, citalopram, mianserin, reboxetine, fluoxetine, fluvoxamine, sertraline, maprotiline, melitracen, paroxetine, desmethylfluoxetine, desmethylmianserin, desmethylmirtazapine, desmethylsertraline, desmethylmaprotiline, desmethylcitalopram, and didesmethylcitalopram) could be quantified. In this article, in addition to the validation of the GC-MS method, four postmortem cases are discussed to demonstrate the usefulness of the described method in forensic toxicology. In these cases, sertraline, fluoxetine, citalopram, and trazodone in combination with their active metabolites were quantified. Blood concentrations ranged from subtherapeutic to toxic concentrations, while brain to plasma ratios ranged from 0.8 to 17. Hair concentrations ranged from 0.4 to 2.5 ng/mg depending on the compound and hair segment.


Assuntos
Antidepressivos/análise , Química Encefálica , Cromatografia Gasosa-Espectrometria de Massas , Cabelo/química , Adulto , Idoso de 80 Anos ou mais , Cromatografia Líquida de Alta Pressão , Feminino , Toxicologia Forense , Humanos , Masculino
13.
Eur J Paediatr Neurol ; 12(4): 321-7, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17950011

RESUMO

PURPOSE: To study the efficacy and tolerability of add-on levetiracetam in children and adolescents with refractory epilepsy. METHODS: In this prospective multi-centre, open-label, add-on study, 33 children aged 4-16 years (median 8.5 years) with epilepsy refractory to at least two antiepileptic drugs were treated with levetiracetam in addition to their present treatment regimen with a follow-up of 26 weeks. The starting dose of 10 mg/kg/day was increased with 2-week steps of 10 mg/kg/day, if necessary, up to a maximum dose of 60 mg/kg/day. RESULTS: Retention rate was 69.7% after 26 weeks on a median levetiracetam dosage of 22 mg/kg/day. Four children dropped-out because levetiracetam was ineffective, four because seizure frequency increased and/or seizures became more severe, and two because they developed aggressive behaviour. Compared to their baseline seizure frequency, 13 children (39.4%) had a >50% seizure reduction 12 weeks after initiation of levetiracetam, and 17 children (51.5%) at 26 weeks. At 26 weeks, nine children (27.3%) had been seizure-free for at least the last 4 weeks, terminal remission ranged from 0 to 187 days (mean 46 days). Levetiracetam was effective in both partial and primary generalized seizures, but had most effect in partial seizures. Most reported side effects were hyperactivity (48.5%), somnolence (36.4%), irritability (33.3%) and aggressive behaviour (27.3%). Severity of most side effects was mild. Five children had a serious adverse event, which all concerned hospital admissions that were not related to levetiracetam use. CONCLUSION: Levetiracetam proved to be an effective and well-tolerated add-on treatment in this group of children with refractory epilepsy.


Assuntos
Epilepsias Parciais/tratamento farmacológico , Epilepsia Generalizada/tratamento farmacológico , Piracetam/análogos & derivados , Convulsões/tratamento farmacológico , Adolescente , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/efeitos adversos , Anticonvulsivantes/uso terapêutico , Criança , Distúrbios do Sono por Sonolência Excessiva/induzido quimicamente , Relação Dose-Resposta a Droga , Esquema de Medicação , Resistência a Medicamentos , Epilepsias Parciais/psicologia , Epilepsia Generalizada/psicologia , Feminino , Seguimentos , Humanos , Humor Irritável/efeitos dos fármacos , Levetiracetam , Masculino , Piracetam/administração & dosagem , Piracetam/efeitos adversos , Piracetam/uso terapêutico , Estudos Prospectivos , Convulsões/psicologia , Resultado do Tratamento
14.
Med Sci Law ; 48(1): 37-50, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18341156

RESUMO

All medico-legal cases of unexpected death during hospitalisation or accommodation in rest or nursing homes, which were investigated at the Department of Forensic Medicine during a 30-year-period, have been reviewed. In the majority of cases, the fatal outcome was bedrail or restraint related, but falls out of bed or from a patient hoist lift can also trigger a death. As expected, the manner of death was mainly accidental. In about 70% of cases, mechanical asphyxia (such as smothering and thoraco-abdominal compression) was substantiated as the mechanism of death. A substantial number of the patients had important medical antecedents, such as cognitive impairment due to cerebro-vascular accidents. In about half of the cases, human negligence was clearly related to the event whereas in only 15% of cases was there a technical mistake. We believe that some sudden and unexpected fatalities, due to physical restraint or other devices (such as a patient hoist lift), are under-reported because of the medico-legal implications. However, reporting such events could induce better precautions and prevent recurrences. Therefore, this study may be important not only for forensic pathologists, but also for a larger group of social workers.


Assuntos
Causas de Morte/tendências , Mortalidade Hospitalar/tendências , Acidentes por Quedas/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Bélgica , Pré-Escolar , Feminino , Humanos , Masculino , Auditoria Médica , Pessoa de Meia-Idade , Restrição Física/estatística & dados numéricos
15.
J Hypertens ; 24(10): 1971-8, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16957556

RESUMO

OBJECTIVE: Angiotensin(1-7) is an active component of the renin-angiotensin-aldosterone system. Its exact role in renal vascular function is unclear. We therefore studied the effects of angiotensin(1-7) on the renal vasculature in vitro and in vivo. METHODS: Isolated small renal arteries were studied in an arteriograph system by constructing concentration-response curves to angiotensin II, without and with angiotensin(1-7). In isolated perfused kidneys, the response of angiotensin II on renal vascular resistance was measured without and with angiotensin(1-7). The influence of angiotensin(1-7) on angiotensin II-induced glomerular afferent and efferent constriction was assessed with intravital microscopy in vivo under anaesthesia. In freely moving rats, we studied the effect of angiotensin(1-7) on angiotensin II-induced reduction of renal blood flow with an electromagnetic flow probe. RESULTS: Angiotensin(1-7) alone had no effect on the renal vasculature in any of the experiments. In vitro, angiotensin(1-7) antagonized angiotensin-II-induced constriction of isolated renal arteries (9.71 +/- 1.21 and 3.20 +/- 0.57%, for control and angiotensin(1-7) pre-treated arteries, respectively; P < 0.0005). In isolated perfused kidneys, angiotensin(1-7) reduced the angiotensin II response (100 +/- 16.6 versus 72.6 +/- 15.6%, P < 0.05) and shifted the angiotensin II dose-response curve rightward (pEC50, 6.69 +/- 0.19 and 6.26 +/- 0.12 for control and angiotensin(1-7) pre-treated kidneys, respectively; P < 0.05). Angiotensin(1-7), however, was devoid of effects on angiotensin-II-induced constriction of glomerular afferent and efferent arterioles and on angiotensin-II-induced renal blood flow reduction in freely moving rats in vivo. CONCLUSION: Angiotensin(1-7) antagonizes angiotensin II in renal vessels in vitro, but does not appear to have a major function in normal physiological regulation of renal vascular function in vivo.


Assuntos
Angiotensina I/farmacologia , Anti-Hipertensivos/farmacologia , Fragmentos de Peptídeos/farmacologia , Artéria Renal/efeitos dos fármacos , Circulação Renal/efeitos dos fármacos , Anestesia , Angiotensina II/farmacologia , Animais , Arteríolas/efeitos dos fármacos , Técnicas In Vitro , Glomérulos Renais/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Vasoconstritores/farmacologia
16.
J Clin Pathol ; 59(4): 355-9, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16489182

RESUMO

BACKGROUND: The implementation of a system based, integrated curriculum at the Faculty of Health Sciences of Stellenbosch University, Western Cape, South Africa, resulted in less contact time for the pathology disciplines during theoretical modules, while a weekly rotation in pathology was introduced during clinical training in the fourth and fifth years. OBJECTIVE: To describe a problem based approach for this rotation. METHODS: Students are presented with a clinical "paper" case daily, integrating as many of the pathology disciplines as possible to demonstrate the interdependence of the various disciplines. They receive chemical pathology tutorials, visit the various laboratories, and receive practical training in fine needle aspiration biopsy. On the final day, the case studies are assessed and discussed. RESULTS: Most students appreciated all activities. This rotation enhanced student interactivity and autonomy and guaranteed immediate feedback. On evaluation of the rotation it was found that the students enjoyed the rotation, learnt something new, and realised the value of group work. CONCLUSIONS: This innovation integrates pathology with clinical practice and illustrates the use of laboratory medicine in the management of common diseases seen in this country. Students appreciate learning practical skills and having to request special investigations under a pathologist's supervision changes their approach to pathology requests. Familiarity with the pathology environment empowers the student to use pathology with greater ease. A bank of case studies that can be expanded to include all medical disciplines will facilitate the application of a problem based approach and enhance communication between the basic science disciplines and the clinical and pathology disciplines.


Assuntos
Estágio Clínico , Educação de Graduação em Medicina/métodos , Patologia Clínica/educação , Aprendizagem Baseada em Problemas/métodos , Biópsia por Agulha Fina/métodos , Currículo , Humanos , Avaliação de Programas e Projetos de Saúde , África do Sul
17.
Forensic Sci Int ; 163(1-2): 1-9, 2006 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-16378701

RESUMO

Investigation of bodies recovered out of water comprises an important proportion of the medico-legal requests. However, the key question whether the victim died due to "true" drowning can frequently not easily be solved. In addition, the diagnosis of hydrocution is even more difficult. In this manuscript, a review of reported diagnostic methods is discussed in order to provide guidelines, which can be used in current forensic practice. In particular, the (dis)advantages of various biological and thanato-chemical methods, described in literature during the last 20 years, will be confronted with the classical techniques such as the detection of diatoms and algae. Indeed, the diatom test is still considered as the "golden standard". In conclusion, the ideal diagnostic test as definite proof for drowning still needs to be established. At present, the combination of the autopsy findings and the diatom test is a good compromise in arriving at a conclusion. Additional biochemical and technical methods could be useful. Unfortunately, the cost-benefit analysis in current practice could be hard to defend. However, the importance of this subject asks for further scientific approaches and research.


Assuntos
Autopsia , Afogamento/diagnóstico , Autopsia/métodos , Causas de Morte , Afogamento/patologia , Medicina Legal , Humanos
18.
Med Sci Law ; 46(1): 37-65, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16454462

RESUMO

Abuse of amphetamine (AMP) and its derivatives, such as 3,4-methylenedioxymethamphetamine (MDMA, 'Ecstasy'), 3,4-methylenedioxyethylamphetamine (MDEA, MDE), and 3,4-methylenedioxyamphetamine (MDA) is an important public issue. Fatalities following ingestion of these substances are not infrequent in current forensic practice. The aim of this study was twofold. Firstly, considering the wide range of blood levels reported in fatalities, to provide insight into the interpretation of a quantified blood level and, secondly, to examine and discuss possible causes, mechanisms and manners of death. All the medico-legal files between January 1976 and December 2004 were skimmed through to investigate whether amphetamine and/or derivatives were involved in the fatal outcome. Particularly, in addition to overdose cases due to or including amphetamines, all amphetamines-related fatalities were examined. In addition to AMP, MDMA, MDEA, and MDA, two other amphetamine derivatives, namely 4-methylthioamphetamine (4-MTA) and para-methoxyamphetamine (PMA) were considered. In 34 fatalities, amphetamines were involved and the majority were men, under the age of 25 years. A wide range of blood levels was found: e.g. MDMA blood concentrations in cases of 'pure' intoxication were found between 0.27 and 13.51 microg/ml. The age and sex distribution as well as the broad range of quantified amphetamines blood levels were in line with those reported in the literature. In our study group, 'pure' intoxications with amphetamines, polydrug overdoses, and the combination of amphetamines use and polytrauma were the most prominent causes of death. Considering the manner of death in these fatalities, unintentional overdoses were most frequent, though suicides, traffic accidents, and criminal offences associated with amphetamines use also accounted for significant percentages. Acute to subacute cardiopulmonary failure was the most frequent mechanism of death, followed by (poly)trauma, mechanical asphyxia, and hyperthermia, respectively. In conclusion, although amphetamines-related fatalities are only a fraction of the total number of fatalities studied at our Department, their contribution to current forensic practice has been increasing during the last few years. As there is still considerable debate as to what level of amphetamines can be toxic or even potentially lethal, it is strongly advisable to interpret the anatomo-pathological findings and the toxicological results together in arriving at a conclusion. This guideline is important in view of the different possible mechanisms of death which implicate quite different survival times following intake of amphetamine and/or its derivatives (e.g. cardiopulmonary complications, hyperthermia).


Assuntos
Transtornos Relacionados ao Uso de Anfetaminas/mortalidade , Anfetaminas/intoxicação , Estimulantes do Sistema Nervoso Central/intoxicação , Transtornos Relacionados ao Uso de Anfetaminas/epidemiologia , Autopsia , Bélgica/epidemiologia , Biometria , Causas de Morte , Overdose de Drogas/mortalidade , Medicina Legal , Humanos
19.
Brain ; 127(Pt 8): 1774-84, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15201192

RESUMO

Knowing the prognosis of epilepsy will undoubtedly influence the treatment strategy. This study aimed to define the prospects of newly diagnosed childhood epilepsy, assess the dynamics of its course, identify relevant variables and develop models to assess the individual prognosis. Four hundred and fifty-three children with newly diagnosed epilepsy were followed for 5 years. Terminal remission at 5 years (TR5) was compared with terminal remission at 2 years (TR2) and with the longest remission during follow-up. Variables defined at intake and at 6 months of follow-up were analysed for their prognostic relevance. In multivariate analyses, combinations of variables were tested to develop reliable models for the calculation of the individual prognosis. Data on treatment, course during follow-up and epilepsy syndromes were also studied. Three hundred and forty-five children (76%) had a TR5 >1 year, 290 (64%) >2 years and 65 (14%) had not had any seizure during the entire follow-up. Out of 108 children (24%) with TR5 <1 year, 27 were actually intractable at 5 years. Medication was started in 388 children (86%). In 227 of these (59%), anti-epileptic drugs (AEDs) could be withdrawn. A TR5 >1 year was attained by 46% on one AED, on the second AED by 19%, and by 9% on all additional AED regimes. Almost 60% of the children treated with a second or additional AED regime had a TR5 >1 year. Variables predicting the outcome at intake were aetiology, history of febrile seizures and age. For intake and 6-month variables combined, sex, aetiology, postictal signs, history of febrile seizures and TR at 6 months were significant. The model derived from intake variables only predicted TR5 <1 year correctly in 36% and TR5 >1 year in 85% (sensitivity 0.65, specificity 0.64). The corresponding values for the model derived from intake and 6-month variables were 43 and 88% (sensitivity 0.69, specificity 0.71). The course of the epilepsy was constantly favourable in 51%, steadily poor in 17%, improving in 25% and deteriorating in 6%. Intractability was in part only a temporary phenomenon. The outcome at 5 years in this cohort of children with newly diagnosed epilepsy was favourable in 76%; 64% were off medication at that time. Almost a third of the children had a fluctuating course; improvement was clearly more common than deterioration. After failure of the first AED, treatment can still be successful. Models predicting the outcome have fewer misclassifications when predicting a long terminal remission than when predicting continuing seizures.


Assuntos
Epilepsia/diagnóstico , Adolescente , Análise de Variância , Anticonvulsivantes/uso terapêutico , Criança , Pré-Escolar , Epilepsia/tratamento farmacológico , Feminino , Seguimentos , Humanos , Lactente , Masculino , Modelos Estatísticos , Prognóstico , Indução de Remissão , Fatores de Risco , Resultado do Tratamento
20.
J Renin Angiotensin Aldosterone Syst ; 6(2): 96-101, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16470489

RESUMO

Angiotensin-converting enzyme inhibitors (ACE-I) reduce proteinuria and protect the kidney in proteinuric renal disease. During ACE-I therapy, circulating levels of angiotensin (1-7) [Ang (1-7)] are increased. As cardiac and renal protective effects of Ang (1-7) have been reported, we questioned whether Ang (1-7) contributes to the anti-proteinuric effects of ACE-I treatment. Therefore, we evaluated whether Ang (1-7) infusion reduces proteinuria in a rat model of adriamycin-induced renal disease. In addition, the effect of a selective Ang (1-7) blocker, [D-Ala7]-Ang (1-7) (A779), was investigated in rats treated with the ACE-I, lisinopril (LIS). Six weeks after induction of proteinuria, therapy was started in four different groups: control, Ang (1-7), LIS, and LIS+A779. After two weeks, the rats were sacrificed. Six weeks after injection of adriamycin, the rats had developed proteinuria of 323+/-40 mg/24 hours. The proteinuria remained stable in the control group and in the Ang (1-7) group, but was reduced in both LIS and LIS+A779-treated groups. Similarly, blood pressure (BP) was unchanged in the control and the Ang (1-7) groups, but reduced in both the LIS and the LIS+A779 groups. Plasma levels of Ang (1-7) were increased in the Ang (1-7) and in both LIS-treated groups. We conclude that systemic Ang (1-7) plays no major role in the anti-proteinuric and BPlowering effects of ACE-I in this rat model of adriamycin-induced nephrosis.


Assuntos
Angiotensina I/fisiologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Fragmentos de Peptídeos/fisiologia , Proteinúria/tratamento farmacológico , Proteinúria/fisiopatologia , Angiotensina I/sangue , Angiotensina I/farmacologia , Angiotensina II/análogos & derivados , Angiotensina II/sangue , Angiotensina II/farmacologia , Animais , Antibióticos Antineoplásicos , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Peso Corporal/fisiologia , Creatina/sangue , Creatinina/sangue , Doxorrubicina , Masculino , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/farmacologia , Peptidil Dipeptidase A/sangue , Proteinúria/induzido quimicamente , Ratos , Ratos Wistar
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