RESUMEN

The unanticipated diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) in a patient after previous neurosurgery can lead to difficult decisions regarding informing contacts. A patient developed sCJD 3 years after neurosurgery. There were 29 potential contacts and 26 were contacted. Twelve completed a questionnaire. The majority of patients wished to know about the contact and to be seen face-to-face, and their main concern was developing the disease despite verbal and written reassurance that this was unlikely. Informing patients of sCJD contact is difficult and can lead to significant patient anxiety. Face-to-face meetings, a helpline and follow-up can help.

Asunto(s)

Síndrome de Creutzfeldt-Jakob/etiología , Síndrome de Creutzfeldt-Jakob/transmisión , Procedimientos Neuroquirúrgicos/efectos adversos , Pacientes/psicología , Revelación de la Verdad , Adulto , Anciano , Anciano de 80 o más Años , Trazado de Contacto , Síndrome de Creutzfeldt-Jakob/psicología , Femenino , Humanos , Enfermedad Iatrogénica , Masculino , Persona de Mediana Edad , Derechos del Paciente , Relaciones Médico-Paciente , Encuestas y Cuestionarios

RESUMEN

Caveolae are abundant in adipocytes and are involved in the regulation of lipid accumulation, which is the main volume determinant of these cells. We have developed and applied a confocal microscopic technique for measuring individual cellular expression of the caveolar proteins cavin-1 and caveolin-1 along with the size of individual adipocytes. The technique was applied on collagenase isolated adipocytes from ad libitum fed Sprague-Dawley rats of different age (4-26 wk) and weight (103-629 g). We found that cellular expression of caveolar proteins was variable (SD of log expression in the range from 0.25 to 0.65). Regression analysis of protein expression on adipocyte size revealed that the expression of the caveolar proteins cavin-1 and caveolin-1 on adipocytes from individual rats was tightly related to adipocyte cell surface area (mean coefficient of regression was 0.83 for cavin and 0.77 for caveolin), indicating that caveolar density was the same in membranes from all cells within a biopsy. This intrinsic relation remained unchanged with animal age, but adipocytes from animals with increasing age showed a decrease in mean expression of caveolar proteins per unit cell surface. The different relation between adipocyte size and cellular expression levels of caveolar proteins within and between individuals of different age shows that caveolar density is an age-sensitive characteristic of adipocytes.

Asunto(s)

Adipocitos/metabolismo , Caveolas/metabolismo , Caveolina 1/biosíntesis , Tamaño de la Célula , Regulación de la Expresión Génica , Proteínas de la Membrana/biosíntesis , Adipocitos/citología , Animales , Caveolina 1/genética , Senescencia Celular/fisiología , Membranas Intracelulares/metabolismo , Proteínas de la Membrana/genética , Microscopía Confocal/métodos , Proteínas de Unión al ARN , Ratas , Ratas Sprague-Dawley

RESUMEN

The aim of the study was to examine the behavior of 242 children, aged between 6 and 16 years, born to mothers with epilepsy. Exposure to sodium valproate (VPA) in utero was associated with high levels of parental stress induced by the child's maladaptive behavior. These children were also poorer for daily living skills and skills relating to socialization. The outcomes on both measures were strongly affected by the Full Scale IQ (FSIQ) of the child; however, no significant differences were found between the groups and therefore this pattern of results cannot simply be attributed to a lower FSIQ. The results of this study suggest that exposure to VPA in utero and the presence of a lowered FSIQ are risk factors for the development of poorer adaptive behavior and a higher rate of maladaptive behaviors.

Asunto(s)

Conducta del Adolescente/efectos de los fármacos , Anticonvulsivantes/efectos adversos , Conducta Infantil/efectos de los fármacos , Efectos Tardíos de la Exposición Prenatal , Actividades Cotidianas , Adaptación Psicológica/efectos de los fármacos , Adolescente , Adulto , Niño , Comunicación , Femenino , Humanos , Persona de Mediana Edad , Padres , Embarazo , Análisis de Regresión , Socialización , Estrés Psicológico/psicología , Encuestas y Cuestionarios , Adulto Joven

RESUMEN

Patients with type 2 diabetes (T2D) and their first-degree relatives (FDRs) are characterized by hypoadiponectinaema and insulin resistance. In T2D patients, plasma adiponectin and insulin sensitivity (SI) increase in response to thiazolidinediones (TZDs). These findings suggest a role for adiponectin in the regulation of SI. We studied the relationship between plasma adiponectin and glucose and lipid metabolism and the effect of troglitazone (200 mg/day) for 12 weeks in 19 normoglycaemic, obese FDR and 20 obese T2D patients, using euglycaemic-hyperinsulinaemic clamps, glycolytic flux calculations and indirect calorimetry. Plasma adiponectin was similar in both groups, despite higher glucose disposal (Rd), glucose oxidation and glycolytic flux and lower lipid oxidation during insulin stimulation in FDR compared with T2D patients. Plasma adiponectin correlated with insulin-stimulated Rd, non-oxidative glucose disposal (NOGD), glucose storage and SI in both groups after adjustment for sex and body fat. The troglitazone-mediated upregulation of plasma adiponectin was associated with increased insulin-stimulated Rd, NOGD and glucose storage in both groups. No effect on endogenous glucose production was observed. In FDR, plasma adiponectin correlated with insulin-stimulated glycogen synthase activity and the troglitazone-induced increase in plasma adiponectin correlated with the improvement in insulin-stimulated Rd and SI after adjustment for sex and body fat. In conclusion, plasma adiponectin in weight-matched FDR and T2D patients is comparably low and correlates with insulin-mediated glucose uptake and storage. Moreover, these data provide evidence for an adiponectin-dependent insulin-sensitizing effect of TZDs at an early stage before development of T2D and that this effect is exerted mainly on insulin-mediated glucose metabolism.

Asunto(s)

Adiponectina/sangre , Hijos Adultos , Cromanos/uso terapéutico , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Tiazolidinedionas/uso terapéutico , Adulto , Análisis de Varianza , Glucemia/análisis , Diabetes Mellitus Tipo 2/enzimología , Femenino , Técnica de Clampeo de la Glucosa , Glucógeno Sintasa/análisis , Humanos , Insulina/sangre , Insulina/uso terapéutico , Masculino , Persona de Mediana Edad , Músculos/química , Triglicéridos/sangre , Troglitazona

RESUMEN

BACKGROUND: In utero exposure to antiepileptic drugs (AEDs) can result in several different teratogenic effects including major malformations, dysmorphic facial features, and learning and behavioural problems. It is estimated that there is a 2-3-fold increase in the risk of malformations compared with the general population. The risk of cognitive impairment and behavioural problems is less clear. OBJECTIVE: To report the frequency and specificity of individual dysmorphic features and to relate the dysmorphic facial phenotype to developmental outcome. METHODS: A retrospective study of 375 children born to 219 mothers with epilepsy. The age of the study group ranged from 6 months to 16 years. Each child underwent a physical examination and a battery of neuropsychological tests. Dysmorphic features were scored from photographs on a blind basis by a panel of dysmorphologists. RESULTS: A total of 274 children were exposed to AEDs (63 to valproate, 94 to carbamazepine, 26 to phenytoin, 15 to other monotherapies, and 76 to polytherapy). Major malformations were identified in 14% of children exposed to valproate in utero, 5% exposed to carbamazepine, and 4% in the non-exposed group. Overall, 47% of exposed children were correctly identified as having been exposed to AEDs in utero. There was a significant correlation between verbal intelligence quotient and dysmorphic facial features in the valproate exposed children only. CONCLUSION: Children exposed to valproate have more distinctive facial features, but a subtle and distinctive facial phenotype is also seen in children exposed to carbamazepine. Nearly half (45%) of unexposed children had some of the facial features associated with AED exposure, showing that many of these features may be seen as part of normal variation and that the diagnosis of the fetal anticonvulsant syndrome is difficult to make on the basis of facial gestalt alone. Developmental surveillance should be offered to children with prenatal exposure to AEDs, particularly those with exposure to high doses of valproate.

Asunto(s)

Anomalías Inducidas por Medicamentos/diagnóstico , Anticonvulsivantes/efectos adversos , Facies , Efectos Tardíos de la Exposición Prenatal/diagnóstico , Anomalías Inducidas por Medicamentos/etiología , Adolescente , Antropometría , Carbamazepina/efectos adversos , Niño , Preescolar , Trastornos del Conocimiento/inducido químicamente , Discapacidades del Desarrollo/inducido químicamente , Epilepsia/tratamiento farmacológico , Femenino , Crecimiento , Humanos , Lactante , Inteligencia , Intercambio Materno-Fetal , Pruebas Neuropsicológicas , Embarazo , Complicaciones del Embarazo/tratamiento farmacológico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Síndrome , Ácido Valproico/efectos adversos

RESUMEN

Cav-p60, a specific and ubiquitous caveolar protein, was immunoprecipitated from solubilized rat adipocyte plasma membranes and identified as similar to a GeneBank entry annotated mouse polymerase transcript release factor (PTRF) by MALDI-TOF and MS-MS of major fragments. Cloning and virtual translation of the corresponding rat adipocyte cDNA sequence revealed 98.7% identity with mouse PTRF. In vitro translation of this sequence produced a protein, which was recognized by antibodies to both cav-p60 and PTRF. EM gold labeling studies showed that a rabbit antiserum against murine PTRF immunolabeled caveolae specifically in adipocytes from both mouse and rat. In view of the reported function of the protein, which is exerted in the cell nucleus, its subcellular localization was investigated. We found that the protein could be purified by differential solubilization of a plasma membrane fraction followed by SDS-PAGE, and that the protein was as abundant as caveolin in this fraction. We were unable to detect the protein in cell nuclei by subcellular fractionation or fluorescence microscopy. The results show that in a large number of cell types, PTRF is essentially located to caveolae, and that each caveola harbors many copies of the protein. Consequently, we suggest the name Cavin for this protein.

Asunto(s)

Caveolas/química , Caveolinas/química , Citosol/química , Proteínas de la Membrana/química , Adipocitos/ultraestructura , Secuencia de Aminoácidos , Animales , Membrana Celular/ultraestructura , Humanos , Inmunoprecipitación , Masculino , Espectrometría de Masas , Proteínas de la Membrana/genética , Proteínas de la Membrana/aislamiento & purificación , Ratones , Microscopía Fluorescente , Datos de Secuencia Molecular , Biosíntesis de Proteínas , Proteínas de Unión al ARN/análisis , Ratas , Ratas Wistar , Alineación de Secuencia

RESUMEN

OBJECTIVE: To investigate the long-term differential drug effects on cognitive functioning in school-aged children exposed to antiepileptic drugs (AEDs) in utero. METHODS: Mothers with epilepsy were recruited from specialist epilepsy clinics and obstetric clinics from the Liverpool and Manchester region. The mothers and their children were recruited without prior knowledge of their AED treatment during pregnancy or the health of the offspring. A battery of neuropsychological tests was applied to each mother-child pair in order to obtain a neuropsychological profile for each child. RESULTS: Neuropsychological investigation was performed on 249 children between the ages of 6 and 16. Children exposed to sodium valproate had a significantly lower verbal IQ when compared to children exposed to other antiepileptic drugs or not exposed at all. The same children were more likely to have an IQ below 69 and more likely to have memory impairment when compared to the other groups. The mothers' IQ, exposure to sodium valproate, and the number of tonic-clonic seizures during pregnancy were significant predictors of verbal IQ in this population. CONCLUSIONS: This retrospective study highlights the potential harmful effects of sodium valproate exposure in utero on neuropsychological development.

Asunto(s)

Anticonvulsivantes/efectos adversos , Trastornos del Conocimiento/inducido químicamente , Trastornos del Conocimiento/psicología , Epilepsia/tratamiento farmacológico , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Efectos Tardíos de la Exposición Prenatal/psicología , Adolescente , Encéfalo/efectos de los fármacos , Encéfalo/crecimiento & desarrollo , Encéfalo/fisiopatología , Niño , Trastornos del Conocimiento/fisiopatología , Estudios de Cohortes , Femenino , Humanos , Discapacidad Intelectual/inducido químicamente , Discapacidad Intelectual/fisiopatología , Discapacidad Intelectual/psicología , Inteligencia/efectos de los fármacos , Masculino , Trastornos de la Memoria/inducido químicamente , Trastornos de la Memoria/fisiopatología , Trastornos de la Memoria/psicología , Pruebas Neuropsicológicas , Embarazo , Estudios Retrospectivos , Reino Unido , Ácido Valproico/efectos adversos

RESUMEN

OBJECTIVES: To determine the prevalence of cognitive delay and possible associated dysmorphic features in children exposed to antiepileptic drugs (AEDs) in utero. DESIGN: Retrospective study of children born to mothers with epilepsy. SETTING: Regional epilepsy clinics in Liverpool and Manchester, UK. PARTICIPANTS: Children aged between 6 months and 16 years born to mothers with epilepsy. MAIN OUTCOME MEASURES: Structured interviews, hospital records, clinical examination, and psychometric tests (Wechsler) were used to assess exposure and intelligence quotient (IQ). Blinded assessment of photographs was used to score children with characteristic dysmorphic features. RESULTS: A total of 249 children aged 6 and over were studied: 41 were exposed to sodium valproate, 52 to carbamazepine, 21 to phenytoin, 49 to polytherapy, and 80 were unexposed. Mean verbal IQ was significantly lower in the valproate group compared to unexposed and other monotherapy groups. Multiple regression analysis showed that both valproate exposure and frequent tonic-clonic seizures in pregnancy were significantly associated with a lower verbal IQ despite adjusting for other confounding factors. There was a significant negative correlation between dysmorphic features and verbal IQ in children exposed to valproate. CONCLUSIONS: This study identifies valproate as a drug carrying potential risks for developmental delay and cognitive impairment and is the first to suggest that frequent tonic-clonic seizures have a similar effect. Our results need to be interpreted with caution given their retrospective nature. Women with epilepsy need careful counselling about individual risk benefit of AED treatment before pregnancy.

Asunto(s)

Anomalías Inducidas por Medicamentos/etiología , Anticonvulsivantes/efectos adversos , Trastornos del Conocimiento/inducido químicamente , Discapacidades del Desarrollo/inducido químicamente , Epilepsia/tratamiento farmacológico , Inteligencia/efectos de los fármacos , Complicaciones del Embarazo/tratamiento farmacológico , Ácido Valproico/efectos adversos , Anomalías Inducidas por Medicamentos/diagnóstico , Adolescente , Anticonvulsivantes/uso terapéutico , Niño , Preescolar , Trastornos del Conocimiento/diagnóstico , Discapacidades del Desarrollo/diagnóstico , Quimioterapia Combinada , Inglaterra , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Pruebas de Inteligencia , Masculino , Proyectos Piloto , Embarazo , Estudios Retrospectivos , Ácido Valproico/uso terapéutico

RESUMEN

BACKGROUND: The potential adverse effects of antiepileptic drug (AED) exposure in pregnancy have been well recognised but the relative risks of specific antiepileptic drug exposures remain poorly understood. OBJECTIVES: To assess the adverse effects of commonly used antiepileptic drugs on maternal and fetal outcomes in pregnancy in women with epilepsy. Comparison of outcomes following specific antiepileptic drug exposures in utero to unexposed pregnancies in the general population or women with epilepsy are described. The current manuscript reports the first phase of this review which focuses upon neurodevelopmental outcomes in children exposed to antiepileptic drugs in utero. SEARCH STRATEGY: We searched MEDLINE, Pharmline, EMBASE, Reprotox and TERIS from 1966 to December 2003. Review articles and conference abstracts were also hand searched. SELECTION CRITERIA: All randomized controlled trials, prospective cohorts of children of pregnant women with and without epilepsy and case control studies (cases: developmental delay or impaired cognitive outcome, control: normal development) were included. DATA COLLECTION AND ANALYSIS: Methodological quality was assessed using an adapted version of the Newcastle-Ottawa Scale. The wide variety of outcome measures and methodological approaches made meta-analysis difficult and a descriptive analysis of the results is presented. MAIN RESULTS: PART A 1b - DEVELOPMENTAL OUTCOMES: The majority of studies were of limited quality. There was little evidence about which specific drugs carry more risk than others to the development of children exposed in utero. The results between studies are conflicting and while most failed to find a significant detrimental outcome with in utero exposure to monotherapy with carbamazepine, phenytoin or phenobarbitone, this should be interpreted cautiously. There were very few studies of exposure to sodium valproate. Polytherapy exposure in utero was more commonly associated with poorer outcomes, as was exposure to any AEDs when analysis did not take into account type of AED. The latter may reflect the large proportion of children included in these studies who were in fact exposed to polytherapy. REVIEWERS' CONCLUSIONS: PART A 1b - DEVELOPMENTAL OUTCOMES: Based on the best current available evidence it would seem advisable for women to continue medication during pregnancy using monotherapy at the lowest dose required to achieve seizure control. Polytherapy would seem best avoided where possible. More population based studies adequately powered to examine the effects of in utero exposure to specific monotherapies which are used in everyday practice are required.

Asunto(s)

Anticonvulsivantes/uso terapéutico , Epilepsia/tratamiento farmacológico , Complicaciones del Embarazo/tratamiento farmacológico , Anomalías Inducidas por Medicamentos/etiología , Anticonvulsivantes/efectos adversos , Niño , Preescolar , Discapacidades del Desarrollo/inducido químicamente , Quimioterapia Combinada , Femenino , Humanos , Embarazo , Resultado del Embarazo , Efectos Tardíos de la Exposición Prenatal

RESUMEN

AIMS: In vascular smooth muscle cells caveolae are important for signalling mechanisms regulating vascular contraction. In smooth muscle layer of the renal afferent arteriole juxtaglomerular cells (JG cells) are non-contractile renin producing cells that have the capacity to change their phenotype into smooth muscle cells and back again by metaplastic transformation. Signalling mechanisms in JG cells are not fully understood and we therefore investigated if caveolae were present, and thereby could be involved as integrators of cellular signalling in both of these phenotypes of smooth muscle cells. METHODS: Using electron microscopy we compared the number of caveolae in JG cells and smooth muscle cells in the afferent arteriole of the rat kidney. The expression of caveolin and cav-p60 was examined using a combination of immunogold electron microscopy and immunofluorescence microscopy. RESULTS: We found that JG cells have sixfold less caveolae per cell surface sectional length than smooth muscle cells. The expression of cavolin-1 and cav-p60 correlated with the number of caveolae. An examination of the general distribution of caveolae, cav-p60 and caveolins in the rat kidney showed that cav-p60, like caveolin-1, is a specific maker of caveolae. CONCLUSION: The number of caveolae in JG cells is very low, and this makes it unlikely that caveolae are of major importance for the renin secretion specific for JG cells.

Asunto(s)

Caveolas/metabolismo , Caveolinas/análisis , Riñón/citología , Músculo Liso Vascular/citología , Renina/biosíntesis , Animales , Western Blotting/métodos , Inmunohistoquímica/métodos , Riñón/metabolismo , Riñón/ultraestructura , Masculino , Microscopía Electrónica/métodos , Microscopía Fluorescente/métodos , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/ultraestructura , Ratas , Ratas Wistar

RESUMEN

OBJECTIVE: To compare information on body fat changes from questionnaire and clinical examination and to study lipoatrophy in HIV-1 patients on highly active antiretroviral therapy (HAART). METHODS: The study was cross-sectional within a randomized trial. One hundred and sixty-eight male HIV-1 patients were examined by questionnaire and clinical examination. Clinical lipoatrophy was studied and defined as fat wasting in the face, legs and/or arms. Fasting blood samples reflecting lipid and glucose metabolism were taken and the role of indinavir, ritonavir (RTV) and RTV/saquinavir (SQV) on lipoatrophy was investigated. RESULTS: After a median of 17 months on HAART, concordance rates between information on changes in body fat from questionnaire and clinical examination were significant and varied from 70 to 96%. With a positive criteria of lipoatrophy in both assessments, 14% of patients had lipoatrophy. These patients had lower weight (P = 0.0007), weight loss from baseline (P = 0.003), lower circumferences at all measurements (P < 0.01), lower plasma triglycerides and low-density lipoprotein (LDL) (P < 0.05) and longer treatment with stavudine (P = 0.0009). Homeostasis model assessment (HOMA) estimates for insulin resistance and beta-cell function were comparable. Plasma cholesterol, triglycerides and very low-density lipoprotein (VLDL) were higher in patients receiving RTV or RTV/SQV (P < 0.03). CONCLUSION: Questionnaire and clinical assessment provide concordant information on changes in body fat. Lipoatrophic patients on HAART with neither increase in abdominal circumference, nor hyperlipidaemia nor glucose intolerance may have side-effects to protease inhibitor treatment, to nucleoside reverse transcriptase inhibitor treatment (stavudine) or suffer from a drug-independent condition.

Asunto(s)

Infecciones por VIH/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/efectos adversos , Indinavir/efectos adversos , Lipodistrofia/inducido químicamente , Ritonavir/efectos adversos , Saquinavir/efectos adversos , Adulto , Anciano , Fármacos Anti-VIH/efectos adversos , Terapia Antirretroviral Altamente Activa/efectos adversos , Composición Corporal , Estudios Transversales , Quimioterapia Combinada , Intolerancia a la Glucosa/inducido químicamente , Infecciones por VIH/complicaciones , Inhibidores de la Proteasa del VIH/administración & dosificación , Síndrome de Emaciación por VIH/inducido químicamente , Humanos , Hiperlipidemias/inducido químicamente , Indinavir/administración & dosificación , Masculino , Persona de Mediana Edad , Ritonavir/administración & dosificación , Saquinavir/administración & dosificación , Estavudina/efectos adversos , Encuestas y Cuestionarios

RESUMEN

OBJECTIVE: In animals, somatostatin (SRIH) and growth hormone (GH)-releasing hormone (GHRH) increase feeding via a common neural mechanism. Furthermore, SRIH counteracts the suppressive action of corticotrophin-releasing hormone (CRH) on food intake. Hypothetically, SRIH could be involved in the central feeding mechanism in anorexia nervosa (AN). Peripheral administration of pyridostigmine (PD) minimizes the release of hypothalamic SRIH. DESIGN: To study the influence of hypothalamic somatostatinergic inhibition on the exaggerated somatotroph responsiveness to GHRH in patients with severe AN, two GHRH stimulation tests were performed in random order following pretreatment with placebo or PD 2 mg/kg body weight in 13 patients and in 10 age-matched healthy controls. The test procedure was repeated in the patients after weight gain. RESULTS: In controls, PD potentiated the GHRH-stimulated GH rise but this effect was absent in AN patients. The relative potentiating effect of PD was inversely correlated to cortisol excretion levels and positively correlated to leptin serum levels. After weight gain the relative PD effect increased twofold. CONCLUSION: The pyridostigmine-GHRH responsive pattern points indirectly to greater SRIH withdrawal and greater GHRH release in anorexia nervosa. Moreover, hypothalamic SRIH activity seems to be inversely related to cortisol levels, indirectly supporting the hypothesis that SRIH and CRH neuronal activity are inversely related in anorexia nervosa. Leptin, which is believed to act on hypothalamic feeding mechanisms, seems to be positively related to SRIH activity. Finally, the present data demonstrate that the potentiating effect of pyridostigmine in anorexia nervosa is related to body mass index and increases upon weight gain, suggesting that the low somatostatinergic tone is not primary but is related to the weight loss.

Asunto(s)

Anorexia Nerviosa/fisiopatología , Hormona de Crecimiento Humana/sangre , Hipotálamo/fisiopatología , Adulto , Anorexia Nerviosa/sangre , Índice de Masa Corporal , Inhibidores de la Colinesterasa , Sinergismo Farmacológico , Femenino , Hormona Liberadora de Hormona del Crecimiento/fisiología , Hormonas/sangre , Humanos , Leptina/sangre , Bromuro de Piridostigmina , Aumento de Peso

RESUMEN

Caveolae are plasmalemmal invaginations of uncertain function. In view of the large number of hypotheses on caveolar functions, it is important to identify which components of caveolae are tissue specific and which are general. The only well-characterized major protein of caveolae is caveolin, which exists in three tissue-specific isoforms: caveolin-1, -2, and -3. Recently cav-p60 was characterized as a 60-kDa caveola-specific protein in adipocytes. The distributions of cav-p60 and caveolin isoforms in different rat muscle tissues were examined by immunofluorescence and immunoelectron microscopy. Cav-p60 was present in caveolae of skeletal and heart muscle, in vascular and intestinal smooth muscle, and in adipocyte caveolae. Furthermore cav-p60 was present in endothelial cells and cells of perineural sheaths. Caveolin-1 and -2 were present in adipocytes, endothelial cells, and cells of perineural sheaths. In all kinds of vascular and intestinal smooth muscle, caveolin-1 and -2 were present at high levels, whereas caveolin-3 expression was low or undetectable, depending on the specific smooth muscle subtype. High levels of caveolin-3 were found only in caveolae and T tubules of skeletal and heart muscle. We conclude that cav-p60 is a highly specific marker of caveolae in many if not all cell types having caveolae.

Asunto(s)

Caveolas/metabolismo , Proteínas de la Membrana/metabolismo , Músculo Esquelético/metabolismo , Músculo Liso/metabolismo , Miocardio/metabolismo , Adipocitos/química , Adipocitos/metabolismo , Adipocitos/ultraestructura , Animales , Caveolas/química , Caveolinas/metabolismo , Fraccionamiento Celular , Membrana Celular/metabolismo , Inmunohistoquímica , Masculino , Músculo Esquelético/química , Músculo Esquelético/ultraestructura , Músculo Liso/química , Músculo Liso/citología , Miocardio/química , Miocardio/citología , Isoformas de Proteínas , Ratas , Ratas Wistar

RESUMEN

To search for caveolar proteins, mice were immunised with rat adipocyte membranes. Hybridoma supernatants were screened for antibodies to proteins on the cytosolic face of caveolae by indirect immunoelectron microscopy of immunogold-labelled adipocyte plasma membrane sheets adsorbed on electron-microscope (EM) grids. One of the hybridoma supernatants (2F11) produced a specific labelling of caveolae which was much more intense than that obtained with caveolin-1 antibodies. In Western blots of sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) separated proteins in crude membrane fractions from different rat tissues, 2F11 labelled a band corresponding to 60 kDa. The intensity of 2F11 labelling was high in adipose tissue and in other tissues varied in parallel to caveolin- labelling. In blots of plasma membrane (PM) and light-microsomal (LM) fractions from a homogenate of adipocytes, prior insulin stimulation of the adipocytes translocated GLUT-4 from the LM to the PM fraction, but was without effect on the distribution of the 60-kDa protein labelled by 2F11. Digestion with endoproteinase lys-C produced the same pattern of immunoreactive fragments of the protein in the vesicular PM and LM fractions, indicating similar membrane topology of the 2F11-reactive, 60-kDa protein in vesicles of PM and LM fractions.

Asunto(s)

Adipocitos/química , Caveolinas/análisis , Proteínas Musculares , Adipocitos/efectos de los fármacos , Adipocitos/ultraestructura , Animales , Anticuerpos Monoclonales , Western Blotting , Caveolina 1 , Caveolinas/inmunología , Fraccionamiento Celular , Membrana Celular/química , Transportador de Glucosa de Tipo 4 , Hibridomas , Hipoglucemiantes/farmacología , Insulina/farmacología , Ratones , Microscopía Electrónica , Microscopía Inmunoelectrónica , Microsomas/química , Proteínas de Transporte de Monosacáridos/análisis , Proteínas de Transporte de Monosacáridos/inmunología , Ratas , Ratas Wistar

RESUMEN

The effect of 3 days of intensive treatment with acipimox, an antilipolytic nicotinic acid derivative, on plasma leptin levels was studied in eight patients with Type 2 diabetes mellitus in a double-blind, placebo-controlled, cross-over study. Acipimox reduced plasma free fatty acids (FFA) markedly and lowered plasma triglycerides, glucose and insulin. Plasma leptin levels were elevated in all eight patients during 3 days of acipimox treatment (mean increase+/-s.e.: 2.38+/-0.57ng/ml, P<0.005) and the 24h mean effect of acipimox on leptin levels increased during the experimental period (P<0.03). The effect on plasma insulin and glucose resembled a mirror image of the effect on plasma leptin during 3 days of treatment. The suggestion that leptin mediates insulin resistance and may be involved in the development of the diabetic syndrome cannot be supported by the present results. It has been reported that FFA stimulates leptin secretion. Surprisingly, despite a markedly reduced FFA level, leptin concentration increased in the present study. We suggest that a primary acipimox effect is to increase leptin secretion, and that this prevails over the reduced FFA stimulus.

Asunto(s)

Diabetes Mellitus Tipo 2/sangre , Ácidos Grasos no Esterificados/sangre , Hipolipemiantes/farmacología , Leptina/sangre , Niacina/análogos & derivados , Niacina/farmacología , Pirazinas/farmacología , Área Bajo la Curva , Glucemia/metabolismo , Estudios Cruzados , Método Doble Ciego , Femenino , Humanos , Insulina/sangre , Masculino , Persona de Mediana Edad , Triglicéridos/sangre

RESUMEN

Triacylglycerol synthesis was studied in hepatocytes isolated from fasted/refed rats by EDTA perfusion. Insulin induced a 1.5-fold increase in glucose incorporation into triacylglycerol. Insulin-stimulated triacylglycerol synthesis and insulin-stimulated protein kinase B/Akt activity were inhibited by the phosphatidylinositol 3-kinase inhibitors wortmannin and LY 294002, and the mitogen-activated protein kinase kinase inhibitor PD 98059. Inhibition of p70 ribosomal protein-S6 kinase with rapamycin was without effect. Insulin-stimulated pyruvate dehydrogenase activity was abolished by phosphatidylinositol 3-kinase inhibitors. No effect of insulin on acetyl CoA carboxylase activity was observed.

Asunto(s)

Insulina/metabolismo , Hígado/metabolismo , Sistema de Señalización de MAP Quinasas , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas , Triglicéridos/biosíntesis , Acetil-CoA Carboxilasa/metabolismo , Androstadienos/farmacología , Animales , Células Cultivadas , Cromonas/farmacología , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Femenino , Flavonoides/antagonistas & inhibidores , Glucosa/metabolismo , Hígado/citología , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Morfolinas/farmacología , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-akt , Complejo Piruvato Deshidrogenasa/metabolismo , Ratas , Ratas Wistar , Proteínas Quinasas S6 Ribosómicas/antagonistas & inhibidores , Sirolimus/farmacología , Wortmanina

Asunto(s)

Diabetes Mellitus Tipo 2/fisiopatología , Diabetes Mellitus/fisiopatología , Insulina/fisiología , Obesidad , Proteínas Tirosina Fosfatasas/metabolismo , Animales , Diabetes Mellitus/terapia , Diabetes Mellitus Tipo 2/terapia , Humanos , Resistencia a la Insulina , Ratones , Ratones Noqueados , Proteína Tirosina Fosfatasa no Receptora Tipo 1 , Proteínas Tirosina Fosfatasas/deficiencia , Proteínas Tirosina Fosfatasas/genética , Transducción de Señal

RESUMEN

Anorexia nervosa (AN) is associated with multiple endocrine alterations. In the majority of AN patients, basal and GHRH-stimulated serum GH levels are increased. The metabolic effects of GH are known to be related to its pulsatile secretory pattern. The present study was performed to examine GH pulsatility in AN using the techniques of deconvolution analysis and approximate entropy, which quantify secretory activity and serial irregularity of underlying hormone release not reflected in peak occurrence or amplitudes. To this end, 24-h GH profiles were obtained by continuous blood sampling aliquoted at 20-min intervals in 8 nonfasting patients with AN [body mass index (BMI), 14.2 +/- 0.8 kg/m2; mean +/- SEM) and in 11 age-matched healthy women (BMI, 20.3 +/- 0.5 kg/m2). The deconvolution-estimated half-life of GH was not altered in the AN patients. The pituitary GH secretory burst frequency, burst mass, and burst duration were each significantly increased in women with AN compared to those in normal weight women. A 4-fold increase in daily pulsatile GH secretion was accompanied by a 20-fold increase in basal (nonpulsatile) GH secretion. There were significant negative correlations between BMI and the basal as well as pulsatile GH secretion rates. Moreover, AN patients exhibited significantly greater GH approximate entropy scores than the controls, denoting marked irregularity of the GH release process. In contrast to previous reports in healthy fasting subjects, cortisol levels in AN patients were positively correlated to GH secretion rates. Leptin levels were significantly inversely correlated to the pulsatile, but not the basal, GH secretion rate. The present data demonstrate augmented basal as well as pulsatile GH secretion with disruption of the orderliness of the GH release process in AN. Accordingly, GH secretion in AN probably reflects altered neuroendocrine feedback regulation, e.g. associated with increased hypothalamic GHRH discharge superimposed on reduced hypothalamic somatostatinergic tone.

Asunto(s)

Anorexia Nerviosa/fisiopatología , Hormona de Crecimiento Humana/metabolismo , Factor I del Crecimiento Similar a la Insulina/fisiología , Ciclos de Actividad/fisiología , Adulto , Anorexia Nerviosa/sangre , Anorexia Nerviosa/patología , Densidad Ósea , Retroalimentación , Femenino , Hormonas/sangre , Hormona de Crecimiento Humana/sangre , Humanos , Hidrocortisona/sangre

RESUMEN

OBJECTIVE: In rodents, leptin is involved in regulating eating behaviour, fat storage, and reproductive function. In humans, the serum leptin concentration in obese and normal weight subjects correlates with body mass index, reflecting the body fat store. The serum leptin exhibit diurnal variation, however, this has been reported to be absent in normal weighted amenorrheic athletes. Anorexia nervosa is associated with multiple endocrine abnormalities. Hypothalamic amenorrhoea often precedes the weight loss and may persist after weight recovery. We hypothesized that leptin could be involved in the regulation of eating behaviour and gonadal function in anorexia nervosa. DESIGN: We measured the concentration of leptin in serum samples taken after an overnight fast in 18 female anorexia nervosa patients and 11 controls. To study diurnal variation, eight patients and 11 controls were hospitalized for 24 h and had a standardized diet at regular times. Seven blood samples were obtained at 4 h intervals from each subject. PATIENTS: The patients fulfilled the DSM-IV criteria for anorexia nervosa. The mean body mass index for the patients was 14.2 +/- 2.3 kg/m2 and for controls 20.3 +/- 1.7 kg/m2. RESULTS: The mean fasting leptin concentration as well as the 24 h mean concentration were significantly lower in the anorectic group than in the control group (2.5 +/- 0.9 vs 10.1 +/- 6.1 micrograms/l, P < 0.01 and 2.7 +/- 1.5 vs 10.6 +/- 7.1 micrograms/l, P < 0.01 respectively). In the whole group of subjects (n = 28) a significant positive correlation between the leptin level and body mass index was found (r = 0.63, P < 0.001). In the anorectic group it was found that the leptin level correlated better with body fat percentage than with body mass index. In normalized data the time course of the mean leptin levels showed a monophasic variation with nadir and zenith at about 0900 and 0100 h respectively. However, the individual coefficients of variance were significantly lower in the anorectic group compared to the group of healthy women. CONCLUSION: In patients with anorexia nervosa the leptin level is low, reflecting the low body fat mass, and the relative diurnal variation is strikingly reduced. The similarity to that of normal weighted women with hypothalamic amenorrhoea suggest that altered leptin oscillations may be of particular significance in the hypothalamic regulation of reproductive function.

Asunto(s)

Anorexia Nerviosa/sangre , Ritmo Circadiano , Proteínas/metabolismo , Adolescente , Adulto , Composición Corporal , Índice de Masa Corporal , Estudios de Casos y Controles , Femenino , Humanos , Leptina

RESUMEN

The secretory vesicles of human neutrophils are rapidly mobilizable vesicles that contain several GPI-linked proteins, a characteristic feature of caveolae in other cells. To investigate whether secretory vesicles are structurally related to caveolae, we examined human neutrophils for the presence of caveolin, a major constituent of caveolae, by immunoblotting using monoclonal and polyclonal antibodies. Caveolin was not detected in lysates of human neutrophils nor in isolated plasma membrane/light membrane fractions in which secretory vesicles localize. In contrast, caveolin was readily detected in isolated membranes of adipose cells. We conclude that human neutrophils are devoid of caveolin and that secretory vesicles are not related to caveolae nor dependent on caveolae for mobilization.

Asunto(s)

Caveolinas , Proteínas de la Membrana/análisis , Neutrófilos/química , Adipocitos/química , Western Blotting , Caveolina 1 , Membrana Celular/química , Humanos