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P Pozzilli

Publications and source records attributed to P Pozzilli.

At least 55 records · Page 3Linked to original sources
PubMed2001

Peritoneal dialysis in an infant with type 1 diabetes and hyperosmolar coma.

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.

Acidosis, Lactic↗
PubMed2001

Intradermal skin test with diabetes specific antigens in patients with type 1 diabetes.

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.

Adolescent↗
PubMed2001

Biochemical markers of type 1 diabetes: clinical use.

In type 1 diabetes, a number of specific and non-specific antigens have been identified. The major autoantigens involved in the destructive process of beta-cells leading to the development of type 1 diabetes are proinsulin/insulin, glutamic acid decarboxylase (GAD) and the transmembrane protein tyrosine phosphatase (IA-2). These are the only autoantigens that partially satisfy the criteria by which an autoantigen or cross-reactive nonself antigen could be evaluated for a pathogenic role in autoimmune diseases. Antigens by definition induce antibody production and in type 1 diabetes, such (auto) antibodies are accepted as biochemical markers for the disease. Here we describe the main features and usefulness of these markers for disease prediction.

Animals↗
PubMed2001

Is the process of beta-cell destruction in type 1 diabetes at time of diagnosis more extensive in females than in males?

OBJECTIVE: To evaluate sex differences in patients with insulin-dependent diabetes mellitus (type 1 diabetes) by comparing the integrated parameters of metabolic control at the time of clinical diagnosis and 3 months after intensive insulin therapy in pre-pubertal, pubertal and post-pubertal patients. DESIGN: A total of 331 consecutive patients with newly diagnosed type 1 diabetes were studied. The mean age of the group was 15 years (s.d. 8.1; range 5-23 years). Patients were stratified into three groups according to their age at disease onset: pre-pubertal (ages 5-9 years), pubertal (ages 10-18 years) and post-pubertal (ages 19-23 years). METHODS: Glycated haemoglobin (HbA(1c)), insulin dose and both basal and glucagon-stimulated C-peptide were evaluated at diagnosis and after 3 months of insulin therapy. RESULTS: We found that females diagnosed after puberty were those with the lowest basal C-peptide compared with males (P=0.005). No statistically significant differences were observed for other metabolic parameters. When the entire group was evaluated, females at the time of diagnosis showed significant lower body mass index (P=0.001), lower basal C-peptide (P=0.021) and higher HbA(1c) (P=0.023) and required more insulin than males (P<0.001). After 3 months of therapy, only a significantly greater dose of insulin was observed in females compared with males (P=0.001), with similar good metabolic control as assessed by HbA(1c). CONCLUSIONS: We conclude that the process of beta-cell destruction at diagnosis may be more extensive in post-pubertal females than in males. Moreover, after the introduction of insulin therapy, females and males show similar metabolic parameters, although females still require significantly more insulin than males to achieve good metabolic control, 3 months after diagnosis.

Adolescent↗
PubMed2001

Autoimmune diabetes not requiring insulin at diagnosis (latent autoimmune diabetes of the adult): definition, characterization, and potential prevention.

Type 1 diabetes is caused by the immune-mediated destruction of islet insulin-secreting beta-cells. This chronic destructive process is associated with both cellular and humoral immune changes in the peripheral blood that can be detected months or even years before the onset of clinical diabetes. Throughout this prediabetic period, metabolic changes, including altered glucose tolerance and reduced insulin secretion, deteriorate at variable rates and eventually result in clinical diabetes. A fraction of individuals with humoral immunological changes have clinical diabetes that initially is not insulin-requiring. The onset of diabetes in these patients is usually in adult life, and because their diabetes is at least initially not insulin-requiring, they appear clinically to be affected by type 2 diabetes. Such patients probably have the same disease process as patients with type 1 diabetes in that they have similar HLA genetic susceptibility as well as autoantibodies to islet antigens, low insulin secretion, and a higher rate of progression to insulin dependency. These patients are defined as being affected by an autoimmune type of diabetes not requiring insulin at diagnosis, which is also named latent autoimmune diabetes of the adult (LADA). Special attention should be paid to diagnose such patients because therapy may influence the speed of progression toward insulin dependency, and in this respect, efforts should be made to protect residual C-peptide secretion. LADA can serve as a model for designing new strategies for prevention of type 1 diabetes but also as a target group for prevention in its own right.

Diabetes Mellitus, Type 1↗
PubMed2000

Natural resistance of human beta cells toward nitric oxide is mediated by heat shock protein 70.

Human beta cells exhibit increased resistance against nitric oxide (NO) radicals as compared with rodent islet cells. Here we tested whether endogenous heat shock protein 70 (hsp70) accounts for the resistance of human cells. Stable transfection of the human beta cell line CM with an antisense hsp70 mRNA-expressing plasmid (ashsp70) caused selective suppression (>95%) of spontaneously expressed hsp70 but not of hsc70 or GRP75 protein. ashsp70 transfection abolished the resistance of CM cells to the NO donors (Z)-1- (2-(2-aminoethyl)-N-(2-ammonioethyl)amino)diazen-1-ium -1,2-diolate and sodium nitroprusside and increased the proportions of necrotic cells 3-5-fold (p < 0.05) and of apoptotic cells about 2-fold (p < 0.01). Re-induction of hsp70 expression by heat shock re-established resistance to NO toxicity. hsp70 did not exert its protective effect at the level of membrane lipid integrity because radical induced lipid peroxidation appeared independent of hsp70 expression. However, after NO exposure only hsp70-deficient cells showed significantly decreased mitochondrial activity, by 40-80% (p < 0.01). These results suggest a key role of hsp70 in the natural resistance of human beta cells against NO induced injury, by preserving mitochondrial function. These findings provide important implications for the development of beta cell protective strategies in type 1 diabetes and islet transplantation.

Animals↗
PubMed2000

No effect of oral insulin on residual beta-cell function in recent-onset type I diabetes (the IMDIAB VII). IMDIAB Group.

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.

Administration, Oral↗
PubMed2000

Twins: mirrors of the immune system.

Twin studies are a powerful tool to assess genetic and nongenetic factors in multifactorial, immune-mediated diseases. Here, Marco Salvetti and colleagues review important results from such studies and highlight their potential value. Future developments that should help to realize the potential of twin studies are discussed.

Humans↗
PubMed2000

Incomplete Freund's adjuvant reduces diabetes in the non-obese diabetic mouse.

As the study of type 1 diabetes moves towards preventive therapy, the role of adjuvants needs to be addressed. Incomplete Freund's adjuvant (IFA) is thought of as "immunologically inert" as, unlike complete FA (CFA), it has no components designed to provoke an immune response. We investigated the effect of IFA as an immunomodulator on the disease process leading to type 1 diabetes in the non-obese diabetic (NOD) mouse. 24 NOD mice were injected intradermally (i.d.) at 8 and 12 weeks of age with a 1:1 mixture of IFA and saline; 24 controls received saline alone. Splenocytes were tested against antigens thought to be involved in the disease process, namely insulin, a GAD peptide, a beta-casein peptide, a Glut-2 peptide and concanavalin A (ConA) as a non-specific antigen. In the IFA experiment diabetes incidence was 13% compared to 38% in the controls (p < 0.05). In vitro, splenocytes from IFA treated animals showed non-specific immunosuppression with ConA (p < 0.01), whereas the response to 1-casein and Glut-2 was raised in IFA treated animals with respect to controls. ELISA using supernatants from IFA treated animals, showed a typical Th2 cytokine pattern, whereas controls showed a Th1 pattern. In conclusion, IFA alone can reduce diabetes incidence in the NOD mouse apparently by modulating the immune response towards beta-cell related specific antigens. As IFA has been adopted as an adjuvant in preventive trials in the NOD mouse, this might have implications for the interpretation of previous and future results.

Animals↗
PubMed2000

Intradermal administration of GAD & evaluation of diabetes incidence in mice: possible relevance for skin tests in humans.

In vitro cell mediated reactivity to Glutamic Acid Decarboxylase (GAD) has been reported in man and in the non-obese diabetic (NOD) mouse. The demonstration of such reactivity in vivo using GAD in a simple intradermal skin test would be useful for mass screening of subjects at risk of Type 1 diabetes. Such a skin test could be simply applied to the forearm, then signs of local reaction would indicate patients at risk. However, in order to safely apply a skin test of this type it must be certain that administration of the antigen does not itself provoke or start the process leading to diabetes in susceptible individuals. In the present study the NOD mouse model was used. GAD and two peptides of GAD, which may have relevance to the disease process, were applied intradermally to these mice to determine whether a local reaction could be seen and to see if the diabetes rate was altered. Moreover, Balb/c mice, which can be considered to be at zero risk of developing the disease, were also injected with the same GAD and GAD peptides. No significant differences were seen in the diabetes incidence of the treatment groups compared to the control groups in either the NOD or Balb/c mice although a local swelling was seen in female NOD mice susceptible to diabetes after GAD administration in the footpad. We conclude that the administration of GAD and/or GAD peptides does not provoke or accelerate diabetes incidence in the NOD mouse and that an intradermal skin-test with GAD may be suitable for preliminary trials aimed at large scale screening of humans for their potential to develop type 1 diabetes.

Age Factors↗
PubMed2000

123I-interleukin-2 scintigraphy for in vivo assessment of intestinal mononuclear cell infiltration in Crohn's disease.

UNLABELLED: Activated mononuclear cells expressing interleukin-2 (IL2) receptors (IL2-Rs) heavily infiltrate the Crohn's disease (CD) gut wall. A new technique for the in vivo detection of tissue infiltrating IL2-R positive (IL2R+ve) cells was developed based on 123I-IL2 scintigraphy. The aim of this study was to investigate whether 123I-IL2 accumulates in the CD gut wall in different phases of the disease and to evaluate the specificity of 123I-IL2 binding to activated IL2R+ve cells infiltrating the gut wall. METHODS: Fifteen patients with ileal CD (10 active and 5 inactive) and 10 healthy volunteers were studied by 123I-IL2 scintigraphy. Six patients with active CD were studied before and after 12 wk of steroid treatment. After scintigraphy, patients were followed up for 29-54 mo. Ex vivo autoradiography was performed to determine specificity of 125I-IL2 binding to IL2R+ve cells. For bowel scintigraphy, 123I-IL2 (75 MBq) was injected intravenously and gamma camera images were acquired after 1 h. Bowel radioactivity was quantified in 64 regions of interest (ROIs). RESULTS: Autoradiography showed specific binding of 125I-IL2 to IL2R+ve mononuclear cells infiltrating the CD gut wall. Intestinal 123I-IL2 uptake assessed by the number of positive ROIs was higher in patients with active or inactive CD than in healthy volunteers (P < 0.0001 and P = 0.03, respectively) and positively correlated with the CD activity index (P = 0.01). 123I-IL2 intestinal uptake significantly decreased in patients with CD in steroid-induced remission (P = 0.03). A significant correlation was observed between the number of positive ROIs and time to disease relapse. CONCLUSION: 123I-IL2 accumulates in the diseased CD gut wall by specific binding to IL2R+ve cells, infiltrating the involved tissues. 123I-IL2 scintigraphy may be an objective tool for the in vivo assessment of intestinal activated mononuclear cell infiltration.

Adult↗
PubMed1999

Troglitazone exhibits immunomodulatory activity on the cytokine production of activated human lymphocytes.

Troglitazone (TGL), a thiazolidinedione compound that improves the response of peripheral target tissue to insulin, also has anti-inflammatory properties, a potential means of protection from Type 1 (insulin dependent) diabetes. In order to test the ability of TGL to affect cytokine production, peripheral blood mononuclear cells from healthy donors were exposed to TGL in the presence or absence of a polyclonal activator (PHA) and the production of cytokines assayed. TGL enhanced PHA response, promoted secretion of the cytokines granulocyte and macrophage colony-stimulating factor and leukaemia inhibitory factor and inhibited tumour necrosis factor-alpha secretion, consistent with causing Th-2 differentiation in T-cells. These results suggest that TGL is capable of modulating cytokine production and could therefore influence Th1/Th2 differentiation.

Chromans↗