RESUMEN
This paper describes severe hyperinsulinemic hypoglycemia during bolus enteral feeding in two neurologically impaired children. Both children were affected by dysphagia with swallowing difficulties; caloric intake was inadequate. For these reasons, percutaneous endoscopic gastrostomy had been positioned during the first months of life. In one patient due to persisting vomiting, after a few months, a gastrojejunal tube (PEG-J) was inserted. Hypoglycemia was revealed by routine blood tests, without evidence of specific symptoms. Continuous subcutaneous glucose monitoring showed wide glucose excursions, ranging from hypoglycemia to hyperglycemia. Extremely high levels of insulin were detected at the time of hypoglycemia. A diagnosis of dumping syndrome (DS) was suspected in both children. In the child with PEG, the tip of the gastrostomy catheter was found to be lying in the bulbus duodeni. Once this had been pulled back, hypoglycemic episodes disappeared. The child with PEG-J needed continuous enteral feeding to reach a normal glucose balance. DS is a relatively common complication in children with gastrostomy, but extremely irregular glucose levels, ranging from hypoglycemia to hyperglycemia, and increased insulin secretion had not been previously demonstrated. The incidence of DS is probably underestimated in children receiving enteral feeding for neurological impairment. In these patients intensive monitoring of blood glucose levels should be performed to calibrate meals. Repeated underestimated hypoglycemic episodes could worsen neurological damage and cause a deterioration in clinical conditions.
Asunto(s)
Síndrome de Vaciamiento Rápido/etiología , Gastrostomía/efectos adversos , Hiperinsulinismo/etiología , Hipoglucemia/etiología , Enfermedades Neurodegenerativas/complicaciones , Catéteres/efectos adversos , Hiperinsulinismo Congénito/diagnóstico , Diagnóstico Diferencial , Síndrome de Vaciamiento Rápido/diagnóstico , Síndrome de Vaciamiento Rápido/terapia , Nutrición Enteral , Humanos , Hiperinsulinismo/diagnóstico , Hiperinsulinismo/terapia , Hipoglucemia/diagnóstico , Hipoglucemia/terapia , Lactante , Masculino , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
Cell mediated immune response in vitro to a number of antigens has been reported in patients with Type 1 diabetes. The aim of the present study was to develop an in vivo intradermal (delayed type hypersensitivity) skin test using antigens known to be recognized by lymphocytes of patients with Type 1 diabetes and to compare, where possible, the in vivo response to the in vitro T cell proliferation to the same antigens. The skin test was performed in the following group of patients: 55 with recent onset Type 1 diabetes; 16 patients with Type 1 diabetes of longer duration; 10 patients with autoimmune thyroid disease and 20 patients with Latent Autoimmune Diabetes in Adults (LADA). Type 1 diabetes specific antigens for the skin test included glutamic acid decarboxilase (GAD65), insulin and beta casein, whereas diabetes non specific antigens included tetanus toxoid, diphteria, proteus, tubercolin, streptococcus, and glycerol as control. A multitest device consisting of heads delivering intradermally 10 microl of solution containing the antigens was applied to the forearms; the specific antigens were injected in one forearm whereas the non specific antigens were injected in the other forearm. Reading of the reaction, which was considered positive in the presence of a nodule of 2 mm diameter was performed 48 h after the multitest application. The in vitro T cell response to diabetes specific antigens used in the multitest was studied using conventional proliferation assays in patients with recent onset Type 1 diabetes and in age matched normal subjects. Only recent onset Type 1 diabetes patients showed an in vivo positive response to GAD65, such response being detectable in 10 patients (18%). Two patients reacted also to beta casein and insulin, all other patient groups resulted negative but 2 patients with longer duration of Type 1 diabetes. There was no apparent link between the in vivo skin test and in vitro T cell proliferation to GAD65. We conclude that in vivo cell mediated immune reaction to GAD65, insulin and beta casein can be visualized in a minority of patients with recent onset Type 1 diabetes. Further studies are required to determine specificity and whether altering the dose can improve the sensitivity of the test.
Asunto(s)
Caseínas , Diabetes Mellitus Tipo 1/diagnóstico , Glutamato Descarboxilasa , Insulina , Isoenzimas , Adolescente , Adulto , Caseínas/inmunología , Niño , Diabetes Mellitus Tipo 1/inmunología , Femenino , Glutamato Descarboxilasa/inmunología , Humanos , Hipersensibilidad Tardía , Insulina/inmunología , Pruebas Intradérmicas , Isoenzimas/inmunología , Masculino , Persona de Mediana EdadRESUMEN
Hyperosmolar coma which is characterized by severe hyperglycemia in absence of chetosis is very rare in pediatric age with only 11 cases reported in the literature. The outcome of the condition is usually poor with mental retardation being the most common event. Here a case of hyperosmolar coma is described in a female of three months of age who was treated with peritoneal dialysis 11 hours after admittance to hospital. This female patient has been receiving insulin from three months of age and today at the age of 10 years she leads a normal life despite being on insulin therapy. A very low level of C-peptide (<0.3 ng/ml) clearly confirms she is affected by Type 1 diabetes. To our knowledge this is the first case report of hyperosmolar coma in a neonate with Type 1 diabetes who survived this condition without late neurological consequences.
Asunto(s)
Diabetes Mellitus Tipo 1/complicaciones , Coma Hiperglucémico Hiperosmolar no Cetósico/etiología , Coma Hiperglucémico Hiperosmolar no Cetósico/terapia , Diálisis Peritoneal , Acidosis Láctica/complicaciones , Deshidratación/complicaciones , Diabetes Mellitus Tipo 1/terapia , Femenino , Estudios de Seguimiento , Humanos , Hiperglucemia/complicaciones , Hipernatremia/complicaciones , Lactante , Insulina/uso terapéutico , Ácido Láctico/sangre , Convulsiones/complicacionesRESUMEN
BACKGROUND: Bovine beta-casein is a cow's milk protein that targets both humoral and cellular immune responses in patients with Type 1 diabetes and, to a lesser degree, also in normal subjects. In this study we aimed to determine whether the avoidance of cow's milk consumption early in life could prevent the development of antibody response to bovine beta-casein despite the mother being exposed on a daily basis to cow's milk consumption. MATERIALS AND METHODS: We measured the antibody response to bovine beta-casein using an ELISA method in 28 healthy infants under 4 months of age, of whom 16 were exclusively breast-fed and 12 were bottle-fed with cow's milk. In addition, beta-casein antibodies were measured in 37 prepubertal children with Type 1 diabetes and in 31 healthy children who were exposed to cow's milk or dairy products to see whether differences in antibody titers exist in this young age group. Antibodies binding to beta-casein were also evaluated by immunoblotting analysis. RESULTS: Elevated levels of beta-casein antibodies were found in bottle-fed infants compared to breast-fed infants (p<0.0001). Antibody levels to bovine beta-casein were also significantly higher in children with Type 1 diabetes compared to age-matched controls (p=0.03). By western blot analysis we confirmed specific binding to bovine beta-casein in bottle-fed infants, in children with Type 1 diabetes and in controls exposed to cow's milk, but not in infants who were exclusively breast-fed. CONCLUSIONS: The results of this study indicate that breastfeeding within the first 4 months of life prevents the generation of antibody response to bovine beta-casein despite the mothers' consumption of cow's milk during the breastfeeding period. These findings may have relevance for disease prevention.
Asunto(s)
Anticuerpos/sangre , Alimentación con Biberón , Lactancia Materna , Caseínas/inmunología , Diabetes Mellitus Tipo 1/inmunología , Leche/inmunología , Animales , Bovinos , Niño , Productos Lácteos , Ensayo de Inmunoadsorción Enzimática , Humanos , LactanteRESUMEN
AIMS/HYPOTHESIS: Induction of tolerance to insulin is achievable in animal models of Type I (insulin-dependent) Diabetes mellitus by oral treatment with this hormone, which can lead to prevention of the disease. In the Diabetes Prevention Trial of Type I diabetes (DPT-1), oral insulin is given with the aim of preventing disease insurgence. We investigated whether if given at diagnosis of Type I diabetes in humans, oral insulin can still act as a tolerogen and therefore preserve residual beta-cell function, which is known to be substantial at diagnosis. METHODS: A double-blind trial was carried out in patients (mean age +/- SD: 14 +/- 8 years) with recent-onset Type I diabetes to whom oral insulin (5 mg daily) or placebo was given for 12 months in addition to intensive subcutaneous insulin therapy. A total of 82 patients with clinical Type I diabetes ( < 4 weeks duration) were studied. Basal C peptide and glycated haemoglobin were measured and the insulin requirement monitored every 3 months up to 1 year. Insulin antibodies were also measured in 27 patients treated with oral insulin and in 18 patients receiving placebo at the beginning of the trial and after 3, 6 and 12 months of treatment. RESULTS: The trial was completed by 80 patients. Overall and without distinction between age at diagnosis, at 3, 6, 9 and 12 months baseline mean C-peptide secretion in patients treated with oral insulin did not differ from that of those patients treated with placebo. In patients younger than 15 years a tendency for lower C-peptide values at 9 and 12 months was observed in the oral insulin group. Insulin requirement at 1 year was similar between the two groups as well as the percentage of glycated haemoglobin. Finally, IgG insulin antibodies were similar in the two groups at each time point. CONCLUSION/INTERPRETATION: The results of this study indicate that the addition of 5 mg of oral insulin does not modify the course of the disease in the first year after diagnosis and probably does not statistically affect the humoral immune response against insulin.
Asunto(s)
Diabetes Mellitus Tipo 1/tratamiento farmacológico , Insulina/administración & dosificación , Islotes Pancreáticos/metabolismo , Administración Oral , Adolescente , Adulto , Edad de Inicio , Glucemia/metabolismo , Péptido C/sangre , Niño , Diabetes Mellitus Tipo 1/sangre , Método Doble Ciego , Femenino , Hemoglobina Glucada/análisis , Humanos , Inyecciones Subcutáneas , Insulina/uso terapéutico , Islotes Pancreáticos/efectos de los fármacos , Italia , MasculinoRESUMEN
AIMS/HYPOTHESIS: Patients with diabetes mellitus commonly have cardiovascular autonomic dysfunction and an abnormal ventilatory pattern during sleep. Few data are available on these changes in childhood diabetes. We investigated whether young diabetic children with or without diabetic neuropathy have ventilatory dysfunction during sleep and if so, whether these autonomic changes are related to the duration of diabetes and glycaemic control. METHODS: We studied 25 children with insulin-dependent diabetes mellitus (19 boys, mean age 7.72 +/- 1.99 years). All patients were insulin-dependent at diagnosis; blood samples for HbA1c assay were collected on the morning before testing and at 3-month intervals during the preceding year. Patients and control subjects (20 age-matched healthy children, 15 boys) underwent overnight polysomnography. RESULTS: More diabetic patients than control subjects had sleep apnoeas (p = 0.006); apnoeas in patients also lasted longer (p = 0.07). Patients with poorly controlled diabetes had more apnoeas than patients with well-controlled diabetes and than healthy control subjects (p < 0.0001). Respiratory events during sleep correlated significantly with glycaemic control (r = 0.360; p = 0.09) and with the duration of diabetes (r = 0.430; p = 0.04). CONCLUSION/INTERPRETATION: We conclude that respiratory control is compromised very early in children with diabetes. These anomalies are closely related to the duration of diabetes and to glycaemic control. In young children with diabetes, screening of ventilatory control using recording techniques that are simpler than polysomnography could provide an early indication that an adverse cardiopulmonary reaction has begun.
Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus Tipo 1/fisiopatología , Hemoglobina Glucada/análisis , Síndromes de la Apnea del Sueño/epidemiología , Niño , Preescolar , Diabetes Mellitus Tipo 1/sangre , Neuropatías Diabéticas/sangre , Neuropatías Diabéticas/fisiopatología , Femenino , Humanos , Masculino , Polisomnografía , Valores de Referencia , Mecánica RespiratoriaRESUMEN
BACKGROUND: In Caucasians, a small number of Type 1 diabetic patients do not show evidence of humoral islet autoimmunity at disease onset, at least with common screening procedures. In African- and Hispanic-American diabetic children at time of diagnosis, many show no evidence of autoimmunity but have an atypical clinical form of the disease. According to the recent American Diabetes Association classification, this subgroup of autoantibody negative patients is referred to as Type 1b diabetic subjects. In the present study, a homogeneous Caucasian Type 1 diabetic clinic-based cohort has been evaluated at diagnosis using a large panel of diabetes-related antibodies and then characterized for various genetic features in order to identify newly diagnosed Type 1 diabetics who are potentially autoantibody negative, i.e. possibly referrable to as idiopathic Type 1b diabetes. METHODS: Newly diagnosed Type 1 diabetic patients of Italian origin (n=141, mean age 12.0+/-7.6 years) were tested for anti-islet cell, anti-insulin, anti-65 kDa isoform of glutamic acid decarboxylase and anti-amino acid residues 256-979 of the tyrosine-phosphatase IA-2 molecule autoantibodies (Step 1). Only those patients found to be autoantibody negative were tested for anti-disialo-ganglioside GD3, anti-thyroid peroxidase, anti-thyroglobulin, anti-21-OH hydroxylase, anti-gastric parietal cell and anti-transglutaminase antibodies (Step 2). Sera negative for the presence of these six autoantibodies as well were characterized in terms of HLA DRB1, DQB1 and CTLA-4. RESULTS: Six out of 141 subjects (3.5%) were autoantibody negative in the first step of the study and five out of six in the second. These five autoantibody negative patients underwent genetic analysis. Three of them had at least one Type 1 diabetes-related high risk HLA haplotype (3/141, 2.1%) while the remaining two cases showed neutral (DR5-DQB1*0301/DR5-DQB1*0301) or strongly protective (DR2-DQB1*0602/DR2-DQB1*0602) HLA genotypes, respectively (2/141, 1. 4%). CONCLUSIONS: Clinically defined Type 1 diabetic patients with no sign of autoimmunity do exist in a Caucasian population. These patients (2 out of 141) that cannot be classified as Type 1a diabetic patients lack clinical characteristics of Type 1b diabetes and have to be reconsidered for a more appropriate ADA classification. These data suggest the need of further large population-based studies to understand if Type 1b diabetes really occurs in a Caucasian population. The patient with a strongly protective HLA genotype is particularly interesting considering that among Caucasians only a few sporadic cases with Type 1 diabetes and DQB1*0602, have been reported, none of whom was homozygous at DQB1 locus.
Asunto(s)
Antígenos de Diferenciación/genética , Autoanticuerpos/sangre , Diabetes Mellitus Tipo 1/clasificación , Diabetes Mellitus Tipo 1/inmunología , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Inmunoconjugados , Abatacept , Adolescente , Adulto , Edad de Inicio , Alelos , Antígenos CD , Péptido C/sangre , Antígeno CTLA-4 , Niño , Preescolar , Diabetes Mellitus Tipo 1/genética , Exones , Femenino , Glutamato Descarboxilasa/inmunología , Cadenas beta de HLA-DQ , Cadenas HLA-DRB1 , Humanos , Lactante , Islotes Pancreáticos/inmunología , Isoenzimas/inmunología , Italia , Masculino , Factores de Riesgo , Población BlancaRESUMEN
The target molecules of the T-cell response in type 1 diabetes, despite their pathogenic importance, remain largely uncharacterized, especially in humans. Interestingly, molecules such as insulin and glutamic acid decarboxylase (GAD) have been shown to be a target not only of autoantibodies, but also of autoreactive T-lymphocytes both in man and in the non-obese diabetic (NOD) mouse. In the present study we aimed to determine the existence of a specific T-cell response towards the insulinoma-associated protein 2 (IA-2) islet tyrosine phosphatase, a recently identified autoantigen which is the target of autoantibodies strongly associated with diabetes development. Human recombinant IA-2 produced in Escherichia coli, was tested for its reactivity with peripheral blood lymphocytes obtained from 16 newly diagnosed type 1 diabetic patients and from 25 normal controls, 15 of whom were HLA-DR-matched. A T-cell proliferation assay was performed in triplicate employing freshly isolated cells in the absence or in the presence of the antigen to be tested (at two different concentrations: 2 microg/ml and 10 microg/ml). A specific T-cell proliferation (defined as a stimulation index (S.I.) >/=3) was observed against IA-2 used at a concentration of 10 microg/ml (but not of 2 microg/ml) in 8/16 diabetic patients, in 1/15 HLA-DR-matched control subjects (P<0.01 by Fisher exact test) and in 0/10 of the remaining normal individuals. A statistically significant difference (P<0.003 by Mann-Whitney U test) was also observed in S.I. values between patients (3.1+/-1.4) and HLA-DR-matched controls (1.7+/-0.54) employing IA-2 at a concentration of 10 microg/ml. However, when IA-2 was used at a concentration of 2 microg/ml, the difference in S. I. between patients (1.65+/-0.8) and controls (1.0+/-0.3) did not reach statistical significance. In conclusion, these data show the presence of a specific, dose-dependent T-lymphocyte response against the IA-2 islet tyrosine phosphatase at the onset of type 1 diabetes. Consequently, this molecule appears to be a target not only at the B-lymphocyte but also at the T-lymphocyte level, reinforcing the potential pathogenic role of this autoantigen in the islet destructive process.
Asunto(s)
Autoantígenos/inmunología , Autoinmunidad/inmunología , Diabetes Mellitus Tipo 1/inmunología , Proteínas de la Membrana/inmunología , Proteínas Tirosina Fosfatasas/inmunología , Linfocitos T/inmunología , Adolescente , Adulto , Niño , Preescolar , Electroforesis en Gel de Agar , Femenino , Glutamato Descarboxilasa/inmunología , Antígenos HLA-DR/análisis , Prueba de Histocompatibilidad , Humanos , Insulina/inmunología , Masculino , Reacción en Cadena de la Polimerasa , Proteína Tirosina Fosfatasa no Receptora Tipo 1 , Radioinmunoensayo , Proteínas Tirosina Fosfatasas Clase 8 Similares a Receptores , Proteínas Recombinantes , Conteo por CintilaciónRESUMEN
BACKGROUND: Intensive insulin therapy is the gold standard by which Type 1 diabetes is treated. In addition to this therapy, administration of nicotinamide (NA) can be beneficial. This concept is reinforced by the results of a recent meta-analysis of the use of NA in patients with recent-onset Type 1 diabetes. METHODS: In this study we compared two different doses of NA in 74 patients with duration of Type 1 diabetes <4 weeks (mean age 13 years). Patients were randomly allocated in blind to two treatment groups: 38 patients received a dose of 25 mg/kg (b.w.) of NA and 36 patients received a dose of 50 mg/kg (b.w.) of NA. Intensive insulin therapy was carried out in order to optimize metabolic control as soon as possible after diagnosis and to maintain blood glucose level as near to normal as possible. Response to therapy was monitored throughout the study by investigating the occurrence of clinical (complete) remission defined, according to the recommendations of the International Diabetes Immunotherapy Group, as restoration of normal fasting and post-prandial blood glucose without any insulin administration for more than 2 weeks. Moreover, the integrated measures of metabolic control (C-peptide, HbA(1c) and insulin dose) were analysed at 3- month intervals up to 1 year after diagnosis. RESULTS: There were no significant differences in the integrated measures of metabolic control between the two NA treated groups either at onset of the disease or at each 3-month interval up to 1 year after diagnosis, although there was a tendency toward higher insulin dosages in the 50 mg NA group. No significant differences were observed in the rate of clinical remission between the two groups. CONCLUSION: We conclude that patients with recent-onset Type 1 diabetes treated with two different doses of NA, in addition to intensive insulin therapy, show similar residual beta-cell function 1 year later. Since both doses of NA are likely to be effective in reducing beta-cell dysfunction, the smaller dose of 25 mg/kg NA would be sufficient as a higher dose may induce insulin resistance.
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Diabetes Mellitus Tipo 1/tratamiento farmacológico , Niacinamida/administración & dosificación , Niacinamida/uso terapéutico , Adolescente , Adulto , Niño , Preescolar , Diabetes Mellitus Tipo 1/metabolismo , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/uso terapéutico , Insulina/administración & dosificación , Insulina/uso terapéutico , Masculino , Niacinamida/efectos adversos , Tamaño de la Muestra , Resultado del TratamientoRESUMEN
BACKGROUND AND AIMS: The aim of this study was to evaluate the nutritional status of children with type 1 diabetes and to search for possible influences of changes in body composition on aspects of diabetes. METHODS: A group of 96 diabetic subjects (41 males and 55 females) were studied, aged between 3 and 19 years old. The following parameters were examined: weight, stature, 5 skin folds, 7 circumferences, bioelectric impedance, arterial pressure, cholesterolemia, triglyceridemia, insulin dose, HbA1c and duration of disease. RESULTS: Obesity and overweight were present in 34.5% of the sample, but obesity was only observed in females (25.5%). There was also a high percentage of underweight subjects (11.5% of the entire sample). The mean values of weight BMI, 5 skin folds, 4 circumferences, FM (calculated using fold measurement and BIA) and AFA were higher in females, whereas mean values of waist/hip ratio and waist/thigh ratio and FFM (in % of body weight) were higher in males. A close correlation was also found between the 4 weight classes (underweight, normal weight, overweight, obese) and the majority of marker parameters for adiposity (5 folds, 4 circumferences, BIA, FM calculated using BIA, fold measurement and AFA). Of the other parameters examined (mean duration of disease, HbA1c assay, daily insulin dose, total cholesterolemia, triglycerididemia, arterial pressure), only the daily insulin dose showed higher values in females in 3 weight classes (underweight, normal weight and obese). Following a comparison with the control population (2469 subjects), higher mean values were found in the latter compared to diabetic subjects, but only in relation to 3 skin folds (tricipital, subscapular and suprailiac) and one circumference (forearm). CONCLUSIONS: The study shows a high frequency of overweight and obesity in children with type 1 diabetes, comparable to that in the healthy population. The finding of a higher frequency of obesity in diabetic females might be explained by their advanced puberal status, given that almost all the obese diabetic females were aged between 10 and 19 years old. The study confirms the validity of a number of anthropometric measurements (BMI, folds, circumference) and BIA in the evaluation of nutritional status in terms of body composition.
Asunto(s)
Fenómenos Fisiológicos Nutricionales Infantiles , Diabetes Mellitus Tipo 1/metabolismo , Estado Nutricional , Obesidad/metabolismo , Adolescente , Adulto , Antropometría , Peso Corporal , Niño , Preescolar , Femenino , Humanos , Masculino , Estudios RetrospectivosRESUMEN
BACKGROUND AND AIMS: The aim of this study was to evaluate the nutritional status of children with type 1 diabetes and to search for possible influences of changes in body composition on aspects of diabetes. METHODS: A group of 96 diabetic subjects (41 males and 55 females) were studied, aged between 3 and 19 years old. The following parameters were examined: weight, stature, 5 skin folds, 7 circumferences, bioelectric impedance, arterial pressure, cholesterolemia, triglyceridemia, insulin dose, HbA1c and duration of disease. RESULTS: Obesity and overweight were present in 34.5% of the sample, but obesity was only observed in females (25.5%). There was also a high percentage of underweight subjects (11.5% of the entire sample). The mean values of weight BMI, 5 skin folds, 4 circumferences, FM (calculated using fold measurement and BIA) and AFA were higher in females, whereas mean values of waist/hip ratio and waist/thigh ratio and FFM (in % of body weight) were higher in males. A close correlation was also found between the 4 weight classes (underweight, normal weight, overweight, obese) and the majority of marker parameters for adiposity (5 folds, 4 circumferences, BIA, FM calculated using BIA, fold measurement and AFA). Of the other parameters examined (mean duration of disease, HbA1c assay, daily insulin dose, total cholesterolemia, triglycerididemia, arterial pressure), only the daily insulin dose showed higher values in females in 3 weight classes (underweight, normal weight and obese). Following a comparison with the control population (2469 subjects), higher mean values were found in the latter compared to diabetic subjects, but only in relation to 3 skin folds (tricipital, subscapular and suprailiac) and one circumference (forearm). CONCLUSIONS: The study shows a high frequency of overweight and obesity in children with type 1 diabetes, comparable to that in the healthy population. The finding of a higher frequency of obesity in diabetic females might be explained by their advanced puberal status, given that almost all the obese diabetic females were aged between 10 and 19 years old. The study confirms the validity of a number of anthropometric measurements (BMI, folds, circumference) and BIA in the evaluation of nutritional status in terms of body composition.
Asunto(s)
Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus/epidemiología , Obesidad , Adolescente , Adulto , Presión Sanguínea , Composición Corporal , Constitución Corporal , Niño , Preescolar , Colesterol/sangre , Diabetes Mellitus Tipo 1/complicaciones , Impedancia Eléctrica , Femenino , Hemoglobina Glucada/análisis , Humanos , Insulina/administración & dosificación , Insulina/uso terapéutico , Italia/epidemiología , Masculino , Estado Nutricional , Prevalencia , Factores Sexuales , Grosor de los Pliegues Cutáneos , Delgadez/epidemiología , Triglicéridos/sangreRESUMEN
In order to identify common mechanisms of action by which both the platelet-derived growth factor (PDGF) and the tumor promoter tetradecanoyl phorbol acetate (TPA) initiate cell growth, the effects of PDGF and TPA on phosphorylation of cellular proteins were examined in density-inhibited Balb/c-3T3 cells. Cultures were incubated with 32Pi and growth factor, and 32P-labeled cellular proteins were examined after separation by SDS-polyacrylamide gel electrophoresis and autoradiography. TPA and PDGF each induced phosphorylation of a major cytosol protein of approximately 75,000 molecular weight (pp75). Phosphorylation of this protein was not induced by either epidermal growth factor or insulin, neither of which initiate 3T3 cell growth but enhance growth later in the 3T3 cell cycle. pp75 was a single band under reduced and non-reduced conditions, and a single spot was seen on two-dimensional gels. Phosphorylation did not occur at 4 degrees C. Phosphorylation of the protein was observed within 3 min and reached a maximum in 10-30 min. Submitogenic doses of TPA and PDGF induced submaximal phosphorylation. The phosphoprotein was labeled only on serine. Cell free phosphorylation of pp75 occurred at 4 degrees C in the presence of Mg++ and Ca2+. Homogenates from cultures pretreated with TPA phosphorylated pp75 in the presence or absence of Ca2+. Phosphorylation of this protein may possibly be related to activation of the Ca2+-dependent, phospholipid sensitive protein kinase C.
Asunto(s)
Fosfoproteínas/biosíntesis , Factor de Crecimiento Derivado de Plaquetas/farmacología , Acetato de Tetradecanoilforbol/farmacología , Animales , Células Clonales/metabolismo , Citosol/metabolismo , Cinética , Ratones , Peso Molecular , Fosfoproteínas/aislamiento & purificación , FosforilaciónRESUMEN
Laurell crossed immunoelectrophoresis (two-dimensional electroimmunodiffusion) was used to prepare minute amounts of purified parasite antigens complexed with their precipitating antibodies obtained from rabbits. These complexes, emuslified in Freund's complete adjuvant, were then used to prime rabbits for selective production of precipitins to the complexed antigens when the animals were later boosted with whole parasite extract. The IgG antibody from the monospecific antiserum recovered was then utilized in affinity chromatography to isolate from the crude parasite antigen large amounts of specific antigen in one step. Thus the combination of preparatory crossed immunoelectrophoresis for immunization using complexed antigen and affinity chromatography with monospecific antibody offers a powerful procedure for the rapid isolation of specific antigens.