RESUMO
AIM: Rectal prolapse is a profoundly disabling condition, occurring mainly in elderly and parous women. There is no accepted standard surgical treatment, with previous studies limited in methodological quality and size. PROSPER aimed to address these deficiencies by comparing the relative merits of different procedures. METHOD: In a pragmatic, factorial (2 × 2) design trial, patients could be randomised between abdominal and perineal surgery (i), and suture vs resection rectopexy for those receiving an abdominal procedure (ii) or Altemeier's vs Delorme's for those receiving a perineal procedure (iii). Primary outcome measures were recurrence of the prolapse, incontinence, bowel function and quality of life scores (Vaizey, bowel thermometer and EQ-5D) measured up to 3 years. RESULTS: Two hundred and ninety-three patients were recruited: 49 were randomised between surgical approaches (i); 78 between abdominal procedures (ii); and 213 between perineal procedures (iii). Recurrence rates were higher than anticipated, but not significantly different in any comparison: Altemeier's vs Delorme's 24/102 (24%) and 31/99 (31%) [hazard ratio (HR) 0.81; 95% CI 0.47, 1.38; P = 0.4]; resection vs suture rectopexy 4/32 (13%) and 9/35 (26%) (HR 0.45; 95% CI 0.14, 1.46; P = 0.2); perineal vs abdominal 5/25 (20%) and 5/19 (26%) (HR 0.83; 95% CI 0.24, 2.86; P = 0.8). Vaizey, bowel thermometer and EQ-5D scores were not significantly different in any of the comparisons. CONCLUSION: No significant differences were seen in any of the randomised comparisons, although substantial improvements from baseline in quality of life were noted following all procedures.
Assuntos
Procedimentos Cirúrgicos do Sistema Digestório/métodos , Períneo/cirurgia , Prolapso Retal/cirurgia , Reto/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Incontinência Fecal/etiologia , Incontinência Fecal/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Qualidade de Vida , Prolapso Retal/complicações , Recidiva , Técnicas de Sutura , Resultado do TratamentoRESUMO
BACKGROUND: The ACCENT database, with individual patient data for 20 898 patients from 18 colon cancer clinical trials, was used to support Food and Drug Administration (FDA) approval of 3-year disease-free survival as a surrogate for 5-year overall survival. We hypothesised substantive differences in survival estimation with log-normal modelling rather than standard Kaplan-Meier or Cox approaches. METHODS: Time to relapse, disease-free survival, and overall survival were estimated using Kaplan-Meier, Cox, and log-normal approaches for male subjects aged 60-65 years, with stage III colon cancer, treated with 5-fluorouracil-based chemotherapy regimens (with 5FU), or with surgery alone (without 5FU). RESULTS: Absolute differences between Cox and log-normal estimates with (without) 5FU varied by end point. The log-normal model had 5.8 (6.3)% higher estimated 3-year time to relapse than the Cox model; 4.8 (5.1)% higher 3-year disease-free survival; and 3.2 (2.2)% higher 5-year overall survival. Model checking indicated greater data support for the log-normal than the Cox model, with Cox and Kaplan-Meier estimates being more similar. All three model types indicate consistent evidence of treatment benefit on both 3-year disease-free survival and 5-year overall survival; patients allocated to 5FU had 5.0-6.7% higher 3-year disease-free survival and 5.3-6.8% higher 5-year overall survival. CONCLUSION: Substantive absolute differences between estimates of 3-year disease-free survival and 5-year overall survival with log-normal and Cox models were large enough to be clinically relevant, and warrant further consideration.
Assuntos
Neoplasias do Colo/mortalidade , Modelos Estatísticos , Idoso , Ensaios Clínicos Fase III como Assunto , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/cirurgia , Terapia Combinada , Bases de Dados como Assunto , Intervalo Livre de Doença , Determinação de Ponto Final , Fluoruracila/administração & dosagem , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Making a diagnosis of transient non-ketotic hyperglycinaemia (tNKH) can be difficult. We report an infant who presented in the neonatal period with symptoms of NKH. Metabolic studies performed on day 2 of life showed raised cerebrospinal fluid (CSF) and plasma glycine, and a CSF:plasma glycine ratio consistent with NKH; however, a liver biopsy performed on day 5 revealed normal liver glycine cleavage system activity. Subsequently, the child's clinical condition improved in the absence of any therapeutic medication. Clinical assessment and developmental follow-up at 5 months, 1 year, and 2 years were age-appropriate. Guidance for the investigation and management of future suspected cases of tNKH is discussed.
Assuntos
Glicina/metabolismo , Hiperglicinemia não Cetótica/diagnóstico , Aminoácidos/metabolismo , Diagnóstico Diferencial , Feminino , Glicina/sangue , Glicina/líquido cefalorraquidiano , Humanos , Hiperglicinemia não Cetótica/metabolismo , Recém-Nascido , Fígado/metabolismo , Fatores de TempoRESUMO
BACKGROUND: Niemann-Pick disease type C (NPC) is a fatal, autosomal recessive lysosomal storage disease which may present in infancy with cholestatic jaundice and/or hepatosplenomegaly. In cholestatic patients with splenomegaly, a bone marrow aspirate has been advocated as a relatively accessible tissue to demonstrate storage phenomena. Typically in patients with NPC, macrophages with abnormal cholesterol storage, so called foam cells, can be detected in the bone marrow. AIM: To review our experience of bone marrow aspiration in children with NPC presenting with infantile liver disease. METHODS: A retrospective analysis of 11 consecutive children (8 males) from Birmingham Children's Hospital with NPC presenting with infantile liver disease was undertaken. The diagnosis of NPC was confirmed in all cases by demonstrating undetectable or low rates of cholesterol esterification and positive filipin staining for free cholesterol in cultured fibroblasts. RESULTS: The median age at presentation was 1.5 months (range 0.5-10). Bone marrow aspirates showed storage cells in only 7/11 cases. Bone marrow aspirates which had storage cells were undertaken at a median age of 11 months while those with no storage cells were undertaken at median age 2.3 months. The overall sensitivity of bone marrow aspirates for detecting storage cells in children presenting with infantile liver disease was 64%; however, for children who had bone marrow aspirates in the first year of life it was only 57%. CONCLUSIONS: The sensitivity of bone marrow aspirate for the diagnosis of NPC disease in patients presenting with infantile liver disease was lower than previously reported. Where NPC is suspected clinically, definitive investigations should be undertaken promptly. There is a need to develop sensitive screening methods for NPC in children presenting with infantile liver disease.
Assuntos
Medula Óssea/patologia , Hepatopatias/patologia , Doenças de Niemann-Pick/patologia , Fatores Etários , Biópsia por Agulha , Exame de Medula Óssea/métodos , Células Cultivadas , Colesterol/metabolismo , Feminino , Fibroblastos/metabolismo , Humanos , Lactente , Hepatopatias/etiologia , Masculino , Doenças de Niemann-Pick/complicações , Doenças de Niemann-Pick/metabolismo , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
AIMS: MAVERIC was a randomised clinical trial designed to test the possibility of prospectively identifying patients who would benefit most from the implantable cardioverter-defibrillator (ICD) by electrophysiology (EP) study in the context of secondary prevention of sudden cardiac death (SCD) through comparing EP-guided interventions (anti-arrhythmic drugs, coronary revascularization, and ICD) against empirical amiodarone therapy. METHODS: Two hundred and fourteen survivors of sustained ventricular tachycardia (VT), ventricular fibrillation (VF) or SCD were randomized to either treatment strategy, pre-stratified for haemodynamic status at index event, and followed up for a median of 5 years. RESULTS: Of the 106 amiodarone arm patients, 89 (84%) received the drug and 5 (5%) received an ICD after crossing over. Of the 108 EP arm patients, 31 (29%) received an ICD, 46 (43%) received anti-arrhythmic drugs only (mainly amiodarone or sotalol) and 18 (17%) received coronary revascularization but no ICD. No significant differences in survival or arrhythmia recurrence existed between the two treatment arms after 6 years. However, ICD recipients had a lower mortality than non-ICD recipients, regardless of allocated treatment (hazard ratio=0.54, p=0.0391). CONCLUSIONS: Prospective selection of patients to receive the ICD by EP study did not improve survival compared with empirical amiodarone therapy among survivors of VT, VF or SCD, whereas ICD implantation improved survival regardless of allocated treatment. On this basis, routine EP study has no role in the management of such patients, who should be offered empirical ICD therapy according to the results of other secondary prevention ICD trials.
Assuntos
Amiodarona/uso terapêutico , Antiarrítmicos/uso terapêutico , Morte Súbita Cardíaca/prevenção & controle , Desfibriladores Implantáveis , Taquicardia Ventricular/terapia , Protocolos Clínicos , Morte Súbita Cardíaca/epidemiologia , Eletrocardiografia Ambulatorial , Técnicas Eletrofisiológicas Cardíacas , Humanos , Análise Multivariada , Estudos Prospectivos , Medição de Risco , Análise de SobrevidaRESUMO
BACKGROUND: In order to study the mechanisms of action of Troglitazone (TGZ) in vivo in Type 2 diabetes, its effects were studied on glucose metabolism, lipolysis and very low-density lipoprotein (VLDL) apolipoprotein B100 (apoB) kinetics. MATERIALS AND METHODS: A placebo-controlled, double-blind study was performed in 24 diet-treated patients randomized to receive TGZ 600 mg day(-1), TGZ 200 mg day(-1) or placebo for 8 weeks. Glucose and glycerol turnover were assessed after an overnight fast, and during sequential low-dose insulin infusions (0.01 U kg(-1) h(-1) followed by 0.015 U kg(-1) h(-1)) using 6,6-2H Glucose and 1,2,3-2H Glycerol. Very low-density lipoprotein apoB secretion was measured using l-13C-leucine, monitoring isotopic enrichment by gas chromatography-mass spectrometry. Treatment effects were analyzed by analysis of covariance, adjusting for baseline. RESULTS: Therapy resulted in a significant group differences in fasting plasma glucose adjusting for baseline (P=0.039). This was most evident at TGZ 600 mg daily [glucose decrease from (mean +/- SD) 9.2 +/- 2.7 to 6.6 +/- 0.9 mmol L(-1)]. HbA1c and insulin levels did not change significantly. Plasma nonesterified fatty acid (NEFA) levels decreased (P=0.045), most evidently at TGZ 200 mg daily, but glycerol was not significantly affected. Although no significant effects were observed on VLDL apoB or triglyceride concentrations, there were treatment differences in the absolute secretion rate of VLDL apoB of borderline (P=0.056) statistical significance, with a decrease observed at TGZ 600 mg daily [geometric mean, SD range, 0.94 (0.41-2.15) to 0.40 (0.14-1.13 mg kg(-1) h(-1))]. Very low-density lipoprotein apoB fractional secretion rate and pool size were unaffected. The VLDL triglyceride: apoB molar ratio differed between treatment groups (P=0.013), being higher in the TGZ 600 mg group [5714 (4128-7741) to 8092 (5669-11552)]. Neither glucose nor glycerol rates of appearance were significantly altered by TGZ and nor did TGZ affect their suppression by insulin. DISCUSSION: The PPARgamma agonist, troglitazone, decreases fasting glucose and NEFA levels in diet-treated Type 2 diabetes. It may also decrease VLDL particle secretion. These effects would be considered beneficial. The biological importance of the increase in VLDL-triglyceride enrichment warrants further study.
Assuntos
Cromanos/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Tiazolidinedionas/uso terapêutico , Apolipoproteína B-100 , Apolipoproteínas B/farmacocinética , Glicemia/análise , Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus Tipo 2/metabolismo , Ácidos Graxos não Esterificados/sangue , Feminino , Glucose/farmacocinética , Glicerol/farmacocinética , Humanos , Insulina/administração & dosagem , Insulina/sangue , Lipólise , Lipoproteínas VLDL/sangue , Masculino , Pessoa de Meia-Idade , Triglicerídeos/sangue , TroglitazonaRESUMO
We report a 4-year-old boy with multiple sulphatase deficiency (MSD). His early health was good. By the end of his first year there were concerns about developmental delay but by 26 months he showed clear evidence of regression in that he was barely able to sit unsupported and had lost all fine motor and communication skills. At that time he also had widespread mild ichthyosis that cleared completely with the use of emollients. The neurological deterioration suggested a diagnosis of metachromatic leucodystrophy, and a reduction in the leucocyte arylsulphatase A activity was detected. The ichthyosis suggested steroid sulphatase deficiency, and a reduction in the leucocyte steroid sulphatase activity was detected. The enzyme deficiency was much less marked for steroid sulphatase than for arylsulphatase A in this boy. This diversity in enzyme activities is typical of MSD and correlates with the mild ichthyosis in this child. This case shows that even mild ichthyosis should prompt measurement of steroid sulphatase activity in a child of either sex with unexplained neurological deterioration.
Assuntos
Ictiose/complicações , Esfingolipidoses/complicações , Pré-Escolar , Cromossomos Humanos Par 1 , Cromossomos Humanos Par 3 , Humanos , Ictiose/tratamento farmacológico , Ictiose/genética , Masculino , Esfingolipidoses/diagnóstico , Esfingolipidoses/genética , Translocação GenéticaAssuntos
Ataxia/genética , DNA Mitocondrial/genética , Frequência do Gene/genética , Mutação/genética , Doenças do Sistema Nervoso/genética , Polimorfismo Genético/genética , Retinose Pigmentar/genética , Ataxia/complicações , Análise Mutacional de DNA , Humanos , Doenças do Sistema Nervoso/complicações , Retinose Pigmentar/complicaçõesRESUMO
Prenatal diagnosis was performed by both DNA and enzymatic analysis on non-identical twins conceived by in vitro fertilization and at risk of succinate semialdehyde dehydrogenase deficiency. One fetus was predicted to be affected and one unaffected and selective fetal reduction was performed.
Assuntos
Aldeído Oxirredutases/deficiência , Erros Inatos do Metabolismo/diagnóstico , Adulto , Alelos , Amostra da Vilosidade Coriônica , Feminino , Fertilização in vitro , Humanos , Erros Inatos do Metabolismo/enzimologia , Gravidez , Diagnóstico Pré-Natal , Succinato-Semialdeído Desidrogenase , Gêmeos DizigóticosRESUMO
This study reports the development of a mutation screening strategy for tyrosinaemia type I, and the identification of six novel mutations in the FAA gene.
Assuntos
Mutação/genética , Tirosinemias/genética , Mapeamento Cromossômico , Consanguinidade , DNA/genética , Éxons/genética , Testes Genéticos , Humanos , Hidrolases/deficiência , Hidrolases/genética , Polimorfismo Conformacional de Fita Simples , Tirosinemias/tratamento farmacológicoRESUMO
Molluscum contagiosum (MC) occurring on the face, lips, and perioral region is a relatively common manifestation of this infectious disease. MC of the intraoral mucosa has been documented, but is rare. This report details the case of a 52-year-old HIV-seropositive man with MC of the gingiva. A review of the literature discloses only 4 previously reported cases of intraoral MC.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/virologia , Doenças da Gengiva/virologia , Molusco Contagioso/patologia , Diagnóstico Diferencial , Células Epiteliais/virologia , Neoplasias Gengivais/diagnóstico , Granuloma Piogênico/diagnóstico , Soropositividade para HIV/patologia , Humanos , Corpos de Inclusão/virologia , Queratinócitos/virologia , Masculino , Pessoa de Meia-Idade , Papiloma/diagnósticoRESUMO
Conventional approaches to the diagnosis of mitochondrial respiratory chain diseases, using enzyme assays and histochemistry, are laborious and give limited information concerning the genetic basis of a deficiency. We have evaluated the diagnostic value of 12 monoclonal antibodies to subunits of the four respiratory chain enzyme complexes and F(1)F(0)-ATP synthase. Antibodies were used in immunological studies with skin fibroblast cultures derived from patients with diverse mitochondrial diseases, including patients in which the disease was caused by a nuclear genetic defect and patients known to harbor a heteroplasmic mutation in a mitochondrial tRNA gene. Immunoblotting experiments permitted the identification of specific enzyme assembly deficits and immunocytochemical studies provided clues regarding the genetic origin of the disease. The immunological findings were in agreement with the biochemical and genetic data of the patients. Our study demonstrates that characterization of the fibroblast cultures with the monoclonal antibodies provides a convenient technique to complement biochemical assays and histochemistry in the diagnosis of mitochondrial respiratory chain disorders.
Assuntos
Fibroblastos/química , Immunoblotting/métodos , Imuno-Histoquímica/métodos , Imunofenotipagem/métodos , Miopatias Mitocondriais/diagnóstico , Adulto , Anticorpos Monoclonais/imunologia , Células Cultivadas , Transporte de Elétrons , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Mitocôndrias/enzimologia , Miopatias Mitocondriais/genética , Complexos Multienzimáticos/análise , Complexos Multienzimáticos/imunologia , MutaçãoRESUMO
Three patients have been reported with (putative) methylmalonic semialdehyde dehydrogenase (MMSDH) deficiency. The urine metabolic pattern was strikingly different in all, including beta-alanine, 3-hydroxypropionic acid, both isomers of 3-amino- and 3-hydroxyisobutyric acids in one and 3-hydroxyisobutyric and lactic acids in a second, and mild methylmalonic aciduria in a third patient. In an effort to clarify these disparate metabolite patterns, we completed the cDNA structure, and characterized the genomic structure of human MMSDH gene in order to undertake molecular analysis. Only the first patient had alterations in the MMSDH coding region, revealing homozygosity for a 1336G > A transversion, which leads to substitution of arginine for highly conserved glycine at amino acid 446. No abnormalities of the MMSDH cDNA were detected in the other patients. These data provide the first molecular characterization of an inborn error of metabolism specific to the L-valine catabolic pathway.
Assuntos
Aldeído Oxirredutases/deficiência , Aldeído Oxirredutases/genética , Erros Inatos do Metabolismo dos Aminoácidos/enzimologia , Erros Inatos do Metabolismo dos Aminoácidos/genética , Substituição de Aminoácidos , Sequência de Bases , Estudos de Casos e Controles , Primers do DNA/genética , DNA Complementar/genética , Éxons , Feminino , Homozigoto , Humanos , Íntrons , Masculino , Metilmalonato-Semialdeído Desidrogenase (Acilante) , Mutação Puntual , Valina/metabolismoRESUMO
Hypoxic-ischaemic encephalopathy (HIE) was diagnosed in an infant with acidosis. At 7 weeks of age further investigations revealed abnormal neuroimaging (CT and MRI scans) and a raised plasma and CSF lactate. A skeletal-muscle biopsy at 2 months of age confirmed the diagnosis of cytochrome oxidase deficiency. The course of the patient's disorder has taken that of a static encephalopathy (cerebral palsy). Inborn disorders of the respiratory chain should be considered in the differential diagnosis of HIE.
Assuntos
Asfixia Neonatal/etiologia , Hipóxia-Isquemia Encefálica/diagnóstico , Doença de Leigh/diagnóstico , Acidose Láctica/sangue , Acidose Láctica/etiologia , Asfixia Neonatal/diagnóstico , Biópsia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Deficiência de Citocromo-c Oxidase , Diagnóstico Diferencial , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Humanos , Hipóxia-Isquemia Encefálica/complicações , Recém-Nascido , Doença de Leigh/complicações , Imageamento por Ressonância Magnética , Masculino , Músculo Esquelético/enzimologia , Músculo Esquelético/patologia , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Data relating to the impact of bone marrow transplantation (BMT) on sexual functioning are equivocal; some studies have shown no major impact whereas others demonstrate a significant adverse effect on sexual health in patients treated with BMT. Further clarification is required to facilitate treatment choices and follow-up management of patients. METHODS: A cross-sectional study of sexual health and infertility was conducted in 479 patients with acute myeloid leukemia (AML) in first complete remission (CR) who were entered into the UK MRC AML 10 trial comparing allogeneic BMT (Allo-BMT), autologous BMT (A-BMT), and intensive consolidation chemotherapy (CCT). Assessment was made by patient questionnaire via the treating centers for completion and returned directly to the coordinating center. RESULTS: Both Allo-BMT and A-BMT were observed to have severe, highly significant adverse effects on the patients' sexual health. Significantly more BMT patients than CCT patients reported a decrease in interest in sex (48% vs. 24%), sexual activity (53% vs. 35%), pleasure from sex (36% vs. 18%), and ability to have sex (38% vs. 18%) (P < 0.001 in each case). Hormonal disorders and infertility also were more common in BMT patients than in CCT patients. These differences were more apparent in women and remained after adjustment for age. CONCLUSIONS: These results indicate a need to consider quality of life parameters when reviewing treatment options and to instigate effective proactive management strategies for dealing with sexual health problems in leukemia survivors.
Assuntos
Transplante de Medula Óssea/efeitos adversos , Infertilidade/etiologia , Leucemia Mieloide/terapia , Disfunções Sexuais Fisiológicas/etiologia , Doença Aguda , Adolescente , Adulto , Transplante de Medula Óssea/métodos , Estudos Transversais , Feminino , Hormônios/deficiência , Humanos , Leucemia Mieloide/tratamento farmacológico , Libido/fisiologia , Masculino , Indução de Remissão , Transplante Autólogo , Transplante HomólogoRESUMO
Data on 1711 patients, aged up to 55 years, in the MRC AML 10 trial were used to create a prognostic index for use in risk-directed therapy decision making for younger patients with acute myeloid leukaemia (AML). Two parameters, response after course 1 and cytogenetics, were strongly predictive of outcome. For patients with complete remission, partial remission and resistant disease, 5-year survival from the start of course 2 was 53%, 44% and 22% and relapse rates were 46%, 48% and 69% respectively, and for patients with favourable, intermediate and adverse karyotypic abnormalities, survival was 72%, 43% and 17% and relapse rates were 34%, 51% and 75% respectively (all P < 0.0001). Patients with FAB type M3 but no cytogenetic t(15;17) also had a low relapse rate (29%). These three factors were combined to give three risk groups: good (favourable karyotype or M3, irrespective of response status or presence of additional abnormalities), standard (neither good nor poor), poor (adverse karyotype or resistant disease, and no good-risk features). Survival for these three groups was 70%, 48% and 15% respectively and relapse rates were 33%. 50% and 78% (both P < 0.0001). The index is simple (based on just three parameters), robust (derived from 1711 patients), highly discriminatory (55% survival difference between good and poor risk) and validated, so can be applied in the clinical setting to assist with therapeutic decisions as in the current AML 12 trial.
Assuntos
Leucemia Mieloide/terapia , Doença Aguda , Adolescente , Adulto , Criança , Pré-Escolar , Aberrações Cromossômicas , Feminino , Humanos , Lactente , Recém-Nascido , Leucemia Mieloide/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Recidiva , Medição de Risco , Fatores de Risco , Análise de SobrevidaAssuntos
Adrenoleucodistrofia/genética , Mutação , Atrofias Ópticas Hereditárias/genética , Fenótipo , Cromossomo X , Adrenoleucodistrofia/complicações , Células Cultivadas , Criança , DNA Mitocondrial/genética , Ácidos Graxos/sangue , Ácidos Graxos/metabolismo , Fibroblastos/metabolismo , Ligação Genética , Humanos , Masculino , Atrofias Ópticas Hereditárias/complicações , Reação em Cadeia da PolimeraseRESUMO
Mevalonic aciduria is a rare autosomal recessive metabolic disorder, characterized by psychomotor retardation, failure to thrive, hepatosplenomegaly, anemia and recurrent febrile crises. The disorder is caused by a deficient activity of mevalonate kinase due to mutations in the encoding gene. Thus far, only two disease-causing mutations have been identified. We now report four different missense mutations including three novel ones, which were identified by sequence analysis of mevalonate kinase cDNA from three mevalonic aciduria patients. All mutations affect conserved amino acids. Heterologous expression of the corresponding mutant mevalonate kinases as fusion proteins with glutathione S -transferase in Escherichia coli showed a profound effect of each of the mutations on enzyme activity. In addition, immunoblot analysis of fibroblast lysates from patients using specific antibodies against mevalonate kinase identified virtually no protein. These results demonstrate that the mutations affect not only the activity but also the stability of the mutant proteins.
Assuntos
Butadienos/metabolismo , DNA Complementar/genética , Hemiterpenos , Ácido Mevalônico/urina , Pentanos , Fosfotransferases (Aceptor do Grupo Álcool)/deficiência , Adolescente , Adulto , Sequência de Aminoácidos , Substituição de Aminoácidos , Criança , Análise Mutacional de DNA , Escherichia coli/genética , Evolução Fatal , Feminino , Fibroblastos/citologia , Fibroblastos/enzimologia , Regulação Enzimológica da Expressão Gênica , Humanos , Immunoblotting , Lactente , Masculino , Ácido Mevalônico/sangue , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Mutação Puntual , Homologia de Sequência de AminoácidosRESUMO
Mitochondrial DNA depletion syndrome is an autosomal inherited disease associated with grossly reduced cellular levels of mitochondrial DNA in infancy. Most patients are born after a full and uncomplicated pregnancy, are normal at birth, but develop symptoms in the early neonatal period. These observations have led to the suggestion that the patients have a defect affecting the control of mitochondrial DNA copy number after birth. Using immunocytochemical techniques, we demonstrated that the disease is already expressed in amniotic fluid cells. Detection of mitochondrial DNA depletion in these fetal cells indicates that the defect may already be expressed early in embryological development.