Sertoli cell-induced reversal of adult rat pancreatic islet beta-cells into fetal-like status: potential implications for islet transplantation in type I diabetes mellitus

BACKGROUND

Clinical success of pancreatic islet allograft (TX) for the therapy of diabetes mellitus is hampered by several pitfalls, primarily including the restricted availability of donor tissue and the immune- and/or non-immune-related TX's early loss, with the latter not necessarily being prevented by the host's general immunosuppression. Finally, adult islet beta-cells normally exhibit minimal proliferation capacity, which would not permit restoration of an eventually declining TX mass.

METHODS

To address the limited beta-cell growth capacity, we have examined whether in vitro co-culturing adult rat islets (I) with prepubertal homologous Sertoli cells (SC) would stimulate I beta-cell expansion. SC-derived effects on the islets were studied in vitro, both morphologically (confocal laser microscopy) and functionally (glucose-stimulated insulin release). We have also preliminarily examined the in vivo impact of microencapsulated SC + I co-cultures on TX in diabetic mice.

RESULTS

In vitro, we observed that SCs promoted significant beta-cell replication, as I beta-cell mitotic activity increased from 1% to greater than 8%, which coincided with the adult elements reversing into fetal-like status. This finding was coupled with significantly greater insulin release either in basal or in response to glucose, as compared with controls.

CONCLUSIONS

Addition of SC to islets promotes reversal of the adult beta-cell elements into fetal-like conditions, thereby providing a new, potentially powerful tool that could significantly enhance the functional performance of islet TX in diabetic recipients.

Increased risk for endocrine autoimmunity in Italian type 2 diabetic patients with GAD65 autoantibodies

OBJECTIVE

Glutamic acid decarboxylase (GAD)65 autoantibodies (GAD65Ab) in type 2 diabetic subjects with secondary failure to sulphonylurea treatment identify the so-called latent autoimmune diabetes of the adult (LADA). The aim of our study was to estimate the risk for endocrine autoimmunity in type 2 diabetic subjects with GAD65Ab.

DESIGN AND PATIENTS

We analysed serum samples from 600 adult subjects with a clinical diagnosis of type 2 diabetes mellitus for the presence and levels of GAD65Ab and antibodies directed against the islet autoantigen IA-2/ICA512 (IA-2/ICA512Ab). All the patients had been treated initially with hypoglycaemic agents and/or diet for at least 1 year. GAD65Ab+ subjects were studied for the presence of thyroid peroxidase autoantibodies (TPOAb), 21 hydroxylase autoantibodies (21OHAb) and frequency of HLA class II haplotypes.

RESULTS

GAD65Ab were found in 67/600 (11%) and IA-2/ICA512Ab in 12/600 (2%) subjects (P < 0.0001). The presence of GAD65Ab, but not that of IA-2/ICA512Ab, was significantly associated with insulin therapy, low BMI (P < 0.0001) and low basal C-peptide (P < 0.01). Islet-cell antibodies (ICA) were detected in 43/67 (64%) GAD65Ab+ and in 10/12 (83%) IA-2/ICA512Ab + subjects. TPOAb occurred more frequently in GAD65Ab+ (16/67, 24%) than in GAD65Ab-subjects (9/174, 5%) (P < 0.0001). 21OHAb were detected only in GAD65Ab+ subjects (3/67, 4.5%) (P = 0.03 vs. GAD65Ab-subjects). None of the 21OHAb+ subjects had metabolic or clinical signs of adrenal dysfunction. HLA-DRB1*03-DQA1*0501-DQB1*0201 (DR3-DQ2) was significantly more frequent in GAD65Ab+ subjects than in healthy controls (OR = 5.42, corrected P < 0.0026). The presence of TPOAb was significantly associated with DR3-DQ2 (P = 0.024).

CONCLUSIONS

Our study demonstrates that the presence of GAD65Ab identifies a subgroup of type 2 diabetic patients with high risk for thyroid and adrenal autoimmunity, and that both GAD65Ab and TPOAb are associated with the presence of HLA-DR3-DQ2, in these patients.

Association of MHC Class I chain-related A (MIC-A) gene polymorphism with Type I diabetes

AIMS/HYPOTHESIS

A distinct family of MHC genes has been identified in the class III region and denominated MHC Class I chain-related genes (MIC). The MIC-A gene is located between the TNFA and the HLA-B genes. The aim of our study was to test the association of the polymorphism of the MIC-A gene with Type I (insulin-dependent) diabetes mellitus and evaluate the interaction between MIC-A and TNFA, HLA-B, HLA-DR and HLA-DQ gene polymorphism.

METHODS

Type I diabetic (n =95) and healthy (n = 98) Italian subjects were typed for exon 5 of MIC-A and for HLA-DRB1, HLA-DQA1, HLA-DQB1 and TNFA alleles. All subjects were also typed for the presence of HLA-B8 or HLA-B15.

RESULTS

The frequency of MIC-A5 was increased in diabetic subjects (53 % vs 15 %) (OR = 6.1) (corrected p, p(c) < 0.0005). Among HLA class II haplotypes, both HLA-DRB1*03-DQA1*0501-DQB1*0201 (DR3-DQ2) and DRB1*04-DQA1*0301-DQB1*0302 (DR4-DQ8) ("at-risk class II haplotypes") were positively associated with diabetes (OR = 6.7 and 6.0, respectively) (p(c) < 0.003). Also HLA-B8 was more frequent among Type I diabetic subjects than among healthy control subjects (OR = 2.8, p = 0.01). None of the TNFA alleles were statistically significantly associated with Type I diabetes. The MIC-A5 exon was negatively associated with age at clinical onset of diabetes (p = 0.012). Thus, 68 % diabetic subjects younger than 25 years and 29 % older than 25 years were carrying this allele. Both MIC-A5 and the at-risk class II haplotypes were independently associated with Type I diabetes and the combined association of the two markers had the highest relative risk (OR = 172). In subjects younger than 25 years, the OR of MIC-A5 was as high as 21.7 and was more than twofold that of at-risk class II haplotypes (OR = 9.5). The MIC-A5 exon was not in linkage disequilibrium with any of the HLA-class I, class II or TNFA alleles studied.

CONCLUSIONS/INTERPRETATION

The MIC-A gene polymorphism is associated with genetic risk for Type I diabetes and the combination of MIC-A5 and at-risk class II haplotypes is now to be seen as the strongest genetic marker for this disease.

Autoantibody recognition of COOH-terminal epitopes of GAD65 marks the risk for insulin requirement in adult-onset diabetes mellitus

Some type 2 diabetic subjects develop secondary failure to sulphonylurea treatment and require insulin therapy. To test the diagnostic sensitivity and specificity of epitopes of GAD65 autoantibodies (GAD65Ab) for insulin requirement, in patients with latent autoimmune diabetes of the adult, we studied 569 adult subjects with a clinical diagnosis of type 2 diabetes mellitus. All the patients had been initially treated with hypoglycemic agents and/or diet for at least 1 yr. The presence of GAD65Ab (61/569, 10.7%) depended on insulin therapy (P<0.0001), low BMI (P<0.0001), and low basal C-peptide (P = 0.01). The majority of GAD65Ab-positive subjects (47/61, 77%) had antibodies directed to both middle (GAD65-MAb) and COOH-terminal (GAD65-CAb) epitopes. However, GAD65-CAb were more frequent in insulin-treated subjects (92% of GAD65Ab+ individuals) than in subjects treated with hypoglycemic agents and/or diet (18.2% of GAD65Ab+ individuals), while the exclusive presence of GAD65-MAb was more frequent in subjects treated with hypoglycemic agents and/or diet (81.8% vs. 8%) (P<0.0001). The presence of GAD65-CAb had a diagnostic specificity for insulin requirement as high as 99.4% (compared with 96.9% of GAD65Ab as measured in the traditional radiobinding assay) and identified a subgroup of patients with low BMI, low basal C-peptide values, and a need for insulin therapy. Subjects carrying only GAD65-MAb were phenotypically indistinguishable from GAD65Ab-negative patients. Patients positive for GAD65-M+CAb, but not those positive for GAD65-MAb only, showed an increased risk for thyroid autoimmunity, as revealed by the presence of thyroid peroxidase autoantibodies. Our study demonstrates that the use of epitope-specific antibody assays improves the diagnostic specificity of GAD65Ab, and that the presence of GAD65Ab binding to COOH-terminal epitopes is strongly associated with a need for insulin requirement.

Circulating insulin and insulin growth factor-1 are independent determinants of left ventricular mass and geometry in essential hypertension

BACKGROUND

It is unclear whether insulin and insulin-like growth factor-1 (IGF-1) are independent determinants of left ventricular (LV) mass in essential hypertension.

METHODS AND RESULTS

We studied 101 never-treated nondiabetic subjects with essential hypertension. All had 24-hour noninvasive ambulatory blood pressure (ABP) monitoring and a 75-g oral glucose tolerance test. We determined fasting glucose, insulin, and IGF-1 and postload glucose and insulin 2 hours after glucose. Insulin resistance was estimated by the homeostasis model assessment (HOMA(IR)) formula. LV mass showed an association with body mass index (BMI) (r=0.47; P<0.01), postload insulin (r=0.54; P<0.01), HOMA(IR) (r=0.39; P<0.01), and IGF-1 (r=0. 43; P<0.01) and a weaker association with average 24-hour systolic and diastolic ABPs (r=0.29 and r=0.26; P<0.05) and basal insulin (r=0.31; P<0.05). Relative wall thickness was positively related to IGF-1 (r=0.39; P<0.01) but not to fasting or 2-hour postload insulin, HOMA(IR), and glucose. In a multiple regression analysis, the final LV mass model (R(2)=0.64) included IGF-1, postload insulin, average 24-hour systolic ABP, sex, and BMI. IGF-1 and postload insulin accounted for >40% of variability of LV mass. The final model (R(2)=0.36) for relative wall thickness included IGF-1 (16% total explained variability), average 24-hour systolic ABP, sex, BMI, and age but not insulin and HOMA(IR).

CONCLUSIONS

These data indicate that insulin and IGF-1 are powerful independent determinants of LV mass and geometry in untreated subjects with essential hypertension and normal glucose tolerance.

Microsatellite polymorphism of the MHC class I chain-related (MIC-A and MIC-B) genes marks the risk for autoimmune Addison's disease

The major histocompatibility complex class I chain-related MIC-A and MIC-B genes are located on chromosome 6 between the histocompatibility leucocyte antigen (HLA)-B and the B-associated transcript genes. The presence of 21-hydroxylase autoantibodies is a sensitive and specific marker of autoimmune Addison's disease. We studied the polymorphism of exon 5 of the MIC-A gene, of intron 1 of the MIC-B gene, and of HLA-DRB1, -DQA1, and -DQB1 genes in 28 autoimmune (21-hydroxylase autoantibody positive) Addison's disease patients and in 75 healthy subjects from central Italy. The MIC-A5.1 allele was significantly more frequent in Addison's disease patients (79%) than in healthy subjects (36%) [odds ratio (OR) = 6.52, corrected P (Pc) = 0.0015], whereas MIC-A6 was significantly reduced in affected subjects (15% vs. 56%, OR = 0.13, Pc = 0.002). The A5.1/A5.1 genotype had an OR for autoimmune Addison's disease as high as 18.0 and an absolute risk of 1 per 1131. In the presence of MIC-A5.1, MICB-CA-25 was significantly increased in Addison's disease patients (25% vs. 4%, OR = 8.0, P = 0.0039, Pc = 0.047). The MICB-CA-17 allele was absent in Addison's disease patients, but present in more than 25% healthy individuals (OR = 0.10, P = 0.0025, Pc = 0.03). Among HLA-DR and -DQ haplotypes, only DRB1*03-DQA1*0501-DQB1*0201 (DR3/DQ2) was significantly more frequent in Addison's disease patients than in healthy subjects, but only in the presence of MIC-A5.1. The frequency of MIC-A5.1 was significantly increased in Addison's disease patients only in the presence of HLA-DR3-DQ2. Our study demonstrates that susceptibility to autoimmune Addison's disease is linked to the MIC-A microsatellite allele 5.1 and that both MIC-A5.1 and HLA-DR3/DQ2 are necessary to confer increased genetic risk for Addison's disease.

Transplantation of pancreatic islets contained in minimal volume microcapsules in diabetic high mammalians

To minimize technical problems relating to excessive size (600-800 mu in diameter) of standard alginate microcapsules (CSM) for pancreatic islet graft immunoisolation, we have developed two novel minimal volume, chemically identical, capsule prototypes (MVC): 1) coherent microcapsules (CM), and 2) medium-size microcapsules (300-400 mu, MSM). CM, which envelop each individual islet within a thin alginate hydrogel cast, are prepared by emulsification, whereas MSM are made by atomizing the islet-alginate suspension through a special microdroplet generator. Upon graft into diabetic rodents, CM have shown to immunoprotect both allo- and xenogeneic nondiscordant islets, and restored normoglycemia. In higher mammals, at subtherapeutic doses, CM fully immunoprotected islet allografts (pig-->pig), but only temporarily xenografts (dog-->pig). We then used MSM to immunoisolate canine islet allografts in the peritoneal cavity of dogs with spontaneous insulin-dependent diabetes. Of three grafted dogs, two showed full remission of hyperglycemia with insulin withdrawal. MSM could represent an intermediate solution between CSM and CM for peritoneal immunoisolated islet transplants.

Contribution of postprandial versus interprandial blood glucose to HbA1c in type 1 diabetes on physiologic intensive therapy with lispro insulin at mealtime

OBJECTIVE

To quantitate the contribution of postprandial blood glucose, which improves with the short-acting insulin analog lispro [Lys(B28),Pro(B29)] in type 1 diabetes, to the overall 24-h blood glucose concentration and the long-term HbA1c concentration under conditions of different postabsorptive blood glucose.

RESEARCH DESIGN AND METHODS

A total of 24 type 1 diabetic patients on long-term intensive therapy with premeal human regular insulin (Hum-R) and bedtime NPH were randomly assigned to a continuation of Hum-R (group 1, n = 8), lispro (group 2, n = 8), or lispro + NPH (in variable proportions) administered at mealtime (group 3, n = 8) for 3 months, NPH administered at bedtime was continued in all three groups. Data from home blood glucose monitoring were collected, and a 24-h plasma glucose and insulin profile was obtained during a 2-day hospital visit to calculate areas under the postprandial glucose curve (3.5 h after breakfast, 3.5 h after lunch, and 3.0 h after dinner for a total of 10.0 h) and the postabsorptive blood glucose curve (the remaining 14.0 h out of 24.0 h) (AUC). Eight nondiabetic subjects were also studied.

RESULTS

The substitution of Hum-R with lispro (group 2) resulted in lower postprandial blood glucose, but greater postabsorptive blood glucose (P < 0.05 vs. group 1). The postprandial blood glucose AUC was lower (161 +/- 19 vs. 167 +/- 20 mg.100 ml-1.h-1), but the postabsorptive blood glucose AUC was greater (155 +/- 22 vs. 142 +/- 19 mg.100 ml-1.h-1) (P < 0.05). Therefore, the 24-h blood glucose AUC was no different (NS). Consequently, HbA1c was no different (NS). This occurred because in group 2, mealtime lispro resulted in normal prandial plasma insulin, but also resulted in lower interprandial concentration (P < 0.05 vs. group 1). When NPH was added to lispro (30% at breakfast, 40% at lunch, 10% at dinner) in group 3, postabsorptive plasma insulin was similar to group 1 (NS), in group 3, the postprandial blood glucose AUC (153 +/- 17 mg.100 ml-1.h-1) was lower and the postabsorptive blood glucose AUC was no different, as compared with group 1 (NS). Therefore, the 24-h blood glucose AUC was lower (147 +/- 17 vs. 155 +/- 21 and 158 +/- 20 mg.100 ml-1.h-1), and HbA1c was lower (6.41 +/- 0.12 vs. 6.84 +/- 0.2 and 6.96 +/- 0.2% (groups 3, 1, and 2 respectively, P < 0.05). Frequency of hypoglycemia was greater in group 2 (P < 0.05), but not in group 3 (NS) vs. group 1.

Efficacy and safety of acarbose in the treatment of Type 1 diabetes mellitus: a placebo-controlled, double-blind, multicentre study

AIMS

The aim of the study was to evaluate the efficacy and safety of acarbose in patients with Type 1 diabetes mellitus (DM).

METHODS

A multicentre double-blind, randomized, placebo-controlled study was performed. After a 6-week run-in, 121 patients were randomized to acarbose or placebo and to high- or low-fibre diet for 24 weeks. Acarbose dose was 50 mg t.d.s. for the first 2 weeks and 100 mg t.d.s. for the subsequent weeks.

RESULTS

At the end of 24 weeks of treatment the intention to treat analysis showed that acarbose compared with placebo decreased 2 h postprandial plasma glucose levels (12.23 +/- 0.83 vs. 14.93 +/- 0.87 mmol/l; F = 6.1, P < 0.02) (least square means +/- SEM). No significant effect of acarbose was recorded on HbA1c or on the number of hypoglycaemic episodes. The effect of acarbose on blood glucose control was not influenced by the amount of carbohydrate and/or fibre intake. The incidence of adverse events were 75% and 39% in acarbose and placebo groups, respectively; they were mild and confined to the gastrointestinal tract.

CONCLUSIONS

The use of acarbose in combination with insulin reduces postprandial plasma glucose levels in Type 1 diabetic patients who are not satisfactorily controlled with insulin alone but without significant effect on HbA1c.

Long-term intensive treatment of type 1 diabetes with the short-acting insulin analog lispro in variable combination with NPH insulin at mealtime

OBJECTIVE

To establish whether the short-acting insulin analog lispro can be successfully implemented in long-term intensive insulin therapy in type 1 diabetes, and if so, what its effects are on glycemic control and frequency and awareness of hypoglycemia.

RESEARCH DESIGN AND METHODS

We randomized 56 type 1 diabetic patients to treatment with either lispro (n = 28) or human regular insulin (Hum-R; n = 28) as mealtime insulin for 1 year (open design, parallel groups). Lispro was injected at mealtime and Hum-R was given 10-40 min before meals (bedtime NPH was continued on both occasions). With lispro, NPH was added at breakfast (approximately 70/30), lunch (approximately 60/40), and supper (approximately 80/20) (mixing percentage of lispro/NPH) to optimize premeal and bedtime blood glucose.

RESULTS

Total daily insulin units were no different in the two treatment groups, but with lispro approximately 30% less short-acting insulin at meals and approximately 30% more NPH was needed versus Hum-R (P < 0.05). The bedtime NPH dosage was no different. With lispro + NPH, the mean daily blood glucose was lower than with Hum-R (8.0 +/- 0.1 vs. 8.8 +/- 0.1 mmol/l; P < 0.05), HbA1c was lower (6.34 +/- 0.10 vs. 6.71 +/- 0.11%, mean value over 1 year; P < 0.002), and hypoglycemia (blood glucose < or = 3.8 mmol/l) was less frequent (7.4 +/- 0.5 vs. 11.5 +/- 0.7 episodes/patient-month) and tended to occur more within 90 min after meals than in the postabsorptive state (P < 0.05 vs. Hum-R). After 1 year, plasma adrenaline and symptom responses to experimental, stepped hypoglycemia improved with lispro and were closer to the responses of 12 nondiabetic control subjects versus Hum-R both in terms of thresholds and magnitude (P < 0.05).

CONCLUSIONS

We concluded that mealtime injection of lispro + NPH improves the 24-h blood glucose and the percentage HbA1c as compared with Hum-R. The improvement can be maintained long term. Intensive therapy with lispro + NPH results in less frequent hypoglycemia and better awareness and counterregulation of hypoglycemia.

Oral granisetron as prophylaxis for nausea and vomiting during fluorescein angiography. A multicentre, double-blind, randomised, parallel group, placebo-controlled study

BACKGROUND

Prophylaxis with oral Granisetron was assessed in patients undergoing fluorescein angiography (FAG) in order to evaluate its efficacy in reducing patients' discomfort due to nausea and vomiting (4% > 20%) and to ensure completion of the investigation.

EXPERIMENTAL PLAN

Multicentre, randomised, double-blind, placebo-controlled study, with a follow-up visit performed 24 hrs after FAG.

ENVIRONMENT

Five Anaesthesia/Resuscitation and Ophthalmology operational units participated in the study.

PATIENTS

120 patients (24 from each Centre) of both sexes and aged > 18 years, suffering from retinal disorders, were enrolled after informed consent. Pregnancy, lactation, anti-neoplastic treatment, ASA status IV/V were main exclusion criteria. All recruired patients completed the study.

INTERVENTIONS

Ophthalmological evaluation was performed 30 days before and the same day as FAG. Anaesthesiological assessment on the same day as FAG, recording, BP, HR, ASA status, allergic diathesis, allergy to medications and contrast media, concomitant treatments. Oral Granisetrom 1 mg or placebo was given on an empty stomach 1 hr before the injection of 5 ml 20% fluorescein in 3 sec. A follow-up examination was done 24 hrs after FAG.

SURVEY

In both groups nausea, retching and vomiting were seen after fluorescein injection.

RESULTS

The study demonstrated that Granisetron is more active than placebo in controlling nausea (3 cases vs 4), and retching (2 vs 6). It was significantly more effective than placebo in the prevention of vomiting (0 vs 3). Efficacy was evaluated with chi 2, p < or = 0.05).

CONCLUSIONS

The results suggest that Granisetron may be indicated as prophylaxis in patients undergoing FAG in order to prevent or control emesis, improve patients' comfort and ensure successful outcome of the investigation.

Etiological diagnosis of primary adrenal insufficiency using an original flowchart of immune and biochemical markers

Approximately 70-80% of cases of primary adrenal insufficiency are classified as idiopathic. An effective protocol for the etiological diagnosis of primary adrenal insufficiency is needed to ensure correct patient management. With the aim of developing an algorithm for the etiological diagnosis of primary adrenal insufficiency, we studied 56 Italian patients with nonsurgical primary adrenal insufficiency and 24 French patients with X-linked adrenoleukodystrophy (ALD) for serum levels of adrenal cortex, steroid-21-hydroxylase (21OHAb), islet cell (ICA), glutamate decarboxylase (GAD65Ab), IA2/ICA512 (ICA512Ab), thyroid peroxidase (TPOAb) autoantibodies, and plasmatic concentrations of very long chain fatty acids (VLCFA). High levels of 21OH and adrenal cortex antibodies were found in 35/42 (83%) and 17/42 (40%) Italian patients with idiopathic adrenal insufficiency, respectively. Levels of adrenal autoantibodies correlated inversely with disease duration (P < 0.0001). Elevated VLCFA were found in 4/42 (10%) idiopathic patients. A total of 34/35 (97%) idiopathic patients with a disease duration of less than 20 yr was positive for either 21OHSAb or elevated levels of VLCFA. None of 14 patients with posttuberculosis adrenal insufficiency had elevated levels of either adrenal antibodies or VLCFA. ICA, GAD65Ab, ICA512Ab, and TPOAb were found in 6/56 (11%), 8/56 (14%), 4/56 (7%), and 23/56 (41%) patients, respectively. None of 24 French ALD patients with adrenal insufficiency was positive for organ-specific autoantibodies. The measuring of 21OH antibodies and plasma VLCFA levels enabled a correct diagnosis of autoimmune (89%) and ALD (8%) in 97% of patients with idiopathic primary adrenal insufficiency of less than 20 yr of duration. The results of our study have important therapeutic and prognostic implications.

Use of the short-acting insulin analogue lispro in intensive treatment of type 1 diabetes mellitus: importance of appropriate replacement of basal insulin and time-interval injection-meal

To establish whether lispro may be a suitable short-acting insulin preparation for meals in intensive treatment of Type 1 diabetes mellitus (DM) in patients already in chronic good glycaemic control with conventional insulins, 69 patients on intensive therapy (4 daily s.c. insulin injections, soluble at each meal, NPH at bedtime, HbA1c <7.5%) were studied with an open, cross-over design for two periods of 3 months each (lispro or soluble). The % HbA1c and frequency of hypoglycaemia were assessed under four different conditions (Groups I-IV). Lispro was always injected at mealtime, soluble 10-40 min prior to meals (with the exception of Group IV). Bedtime NPH was continued with both treatments. When lispro replaced soluble with no increase in number of daily NPH injections (Group I, n = 15), HbA1c was no different (p = NS), but frequency of hypoglycaemia was greater (p < 0.05). When NPH was given 3-4 times daily, lispro (Group II, n = 18), but not soluble (Group III, n = 12) decreased HbA1c by 0.35 +/- 0.25% with no increase in hypoglycaemia. When soluble was injected at mealtimes, HbA1c increased by 0.18 +/- 0.15% and hypoglycaemia was more frequent than when soluble was injected 10-40 min prior to meals (Group IV, n = 24) (p < 0.05). It is concluded that in intensive management of Type 1 DM, lispro is superior to soluble in terms of reduction of % HbA1c and frequency of hypoglycaemia, especially for those patients who do not use a time interval between insulin injection and meal. However, these goals cannot be achieved without optimization of basal insulin.

Moderate and large doses of ethanol differentially affect hepatic protein metabolism in humans

The intake of approximately 70 g of alcohol impairs liver protein metabolism in healthy humans. To establish the threshold at which alcohol impairs hepatic protein metabolism in humans we compared the effects of 500 mL of water (control study), 300 (28.4 g ethanol) or 750 mL (71 g ethanol) of table wine on hepatic protein metabolism in three groups of healthy nonalcoholic volunteers. Hepatic protein metabolism was estimated (L-[1-14C]leucine infusion) by measuring the fractional secretory rates of albumin and fibrinogen during the overnight postabsorptive state (basal) and the subsequent administration of water or two different amounts of wine (300 or 750 mL) given with a liquid glucose-lipid-amino acid meal. During the meal, water did not affect fibrinogen fractional secretory rate and increased albumin fractional secretory rate by approximately 50% (P < 0.01). The 300 mL of wine increased albumin secretory rate by only approximately 20% (P < 0.01 vs. basal, P < 0.04 vs. water) and did not affect fibrinogen secretory rate. The 750 mL of wine profoundly impaired hepatic protein metabolism, decreasing the fractional secretory rates of albumin (P < 0.01 vs. water and 300 mL wine) and fibrinogen (P < 0.04 vs. water and 300 mL of wine) below the postabsorptive values. These results demonstrate that a moderate dose of alcohol (28 g, approximately 2 drinks) slightly affects postprandial hepatic protein metabolism by blunting the meal-induced increase in albumin synthesis, whereas it does not interfere with fibrinogen synthesis as do higher doses.

Nicotinamide counteracts alcohol-induced impairment of hepatic protein metabolism in humans

We have recently shown that a large amount of wine (750 mL, approximately 70 g of alcohol) markedly impairs postprandial hepatic protein metabolism in healthy subjects. This is probably due to the shift in the intracellular redox state (increased NADH/NAD+) induced by ethanol oxidation. If this hypothesis is true, the administration of nicotinamide (NAD+ precursor) should provide NAD+ in excess and thus correct the NADH/NAD+ abnormalities and prevent the ethanol hepatotoxicity. Whole-body protein metabolism and the fractional secretory rates of hepatic (albumin, fibrinogen) and extra-hepatic (immunoglobulin G, IgG) plasma proteins were measured in the basal postabsorptive and in the absorptive states in 15 healthy subjects, that had been assigned to three groups matched for age and body mass index. During the absorptive state (intragastric meal), the three groups received water (control), 750 mL of wine, or 750 mL of wine + 1.25 g of nicotinamide, respectively. The redox state was estimated by determining the plasma lactate/pyruvate ratio. Compared with the basal state, wine alone increased the lactate/pyruvate ratio twofold and depressed the fractional secretory rates of albumin and fibrinogen (P < 0.01 vs. control and nicotinamide); nicotinamide reduced the effects of wine on the lactate/pyruvate ratio (P < 0.02 vs. wine alone) and prevented the reduction of albumin and fibrinogen secretory rates (P > 0.05 vs. control). These results indicate that nicotinamide counteracts the acute hepatotoxic effects of ethanol by ameliorating the redox state.

Long-term intensive therapy of IDDM patients with clinically overt autonomic neuropathy: effects on hypoglycemia awareness and counterregulation

To test the hypothesis that hypoglycemia unawareness and impaired counterregulation are reversible after meticulous prevention of hypoglycemia in IDDM patients with diabetic autonomic neuropathy (DAN), 21 patients (8 without DAN [DAN-]; 13 with DAN [DAN+]; of the latter, 7 had orthostatic hypotension [DAN+PH+] and 6 did not [DAN+PH-]) and 15 nondiabetic subjects were studied during stepped hypoglycemia (plateau plasma glucose decrements from 5.0 to 2.2 mmol/l) before and 6 months after prevention of hypoglycemia (intensive therapy). After 6 months, frequency of mild hypoglycemia decreased from approximately 20 to approximately 2 episodes/patient-month while HbA1c increased from 6.2 +/- 0.3 to 6.9 +/- 0.2% (P < 0.05). Responses of adrenaline improved more in DAN- patients (from 1.17 +/- 0.12 to 2.4 +/- 0.22 nmol/l) than in DAN+PH- (from 0.75 +/- 0.25 to 1.56 +/- 0.23 nmol/l) and DAN+PH+ patients (from 0.80 +/- 0.24 to 1.15 +/- 0.27 nmol/l, P < 0.05) but remained lower than in nondiabetic subjects (4.9 +/- 0.37 nmol/l, P < 0.05), whereas glycemic thresholds normalized only in DAN-, not DAN+. Autonomic symptoms of hypoglycemia improved but remained lower in DAN- (6.2 +/- 0.6) than in nondiabetic subjects (8.1 +/- 1.1) and lower in DAN+PH+ (4 +/- 0.8) than in DAN+PH- subjects (5.1 +/- 0.8, P < 0.05), whereas neuroglycopenic symptoms normalized (NS). Cognitive function deteriorated less before than after prevention of hypoglycemia (P < 0.05). Thus, intensive therapy with emphasis on preventing hypoglycemia reverses hypoglycemia unawareness in DAN+ patients despite marginal improvement of adrenaline responses, results in low frequency of hypoglycemia despite impaired counterregulation, and maintains HbA1c in the range of intensive therapy. We conclude that DAN, long IDDM duration per se, and antecedent recent hypoglycemia contribute to different extents to impaired adrenaline responses and hypoglycemia unawareness.

Evidence of increased systemic glucose production and gluconeogenesis in an early stage of NIDDM

To assess the mechanisms of fasting hyperglycemia in NIDDM patients with mild elevation of fasting plasma glucose (FPG) compared with NIDDM patients with overt hyperglycemia, we studied 29 patients with NIDDM, who were divided in two groups according to their fasting plasma glucose (<7.8 and > or =7.8 mmol/l for groups A and B, respectively), and 16 control subjects who were matched with NIDDM patients for age, sex, and body mass index. All subjects were infused with [3-3H]glucose between 10:00 P.M. and 10:00 A.M. during overnight fasting to determine glucose fluxes. In 27 subjects (17 diabetic and 10 control), [U-14C]alanine was simultaneously infused between 4:00 A.M. and 10:00 A.M. to measure gluconeogenesis (GNG) from alanine. Arterialized-venous plasma samples were collected every 30 min for measurement of glucose fluxes, GNG, and glucoregulatory hormones. In group A, plasma glucose, rate of systemic glucose production (SGP), and GNG were greater than in control subjects (7.2 +/- 0.2 vs. 4.9 +/- 0.1 mmol/l, 10.9 +/- 0.2 vs. 9.5 +/- 0.3 micromol x kg(-1) x min(-1), and 0.58 +/- 0.04 vs. 0.37 +/- 0.02 micromol x kg(-1) x min(-1), respectively, for group A and control subjects; mean value 8:00 A.M.-10:00 A.M., all P < 0.05). Both increased SGP and GNG correlated with plasma glucose in all subjects (r = 0.77 and r = 0.75, respectively, P < 0.005). Plasma counterregulatory hormones did not differ in NIDDM patients compared to control subjects. The present studies demonstrate that SGP and GNG are increased in NIDDM patients without overt fasting hyperglycemia. Thus these metabolic abnormalities primarily contribute to early development of overnight and fasting hyperglycemia in NIDDM.

Contribution of autonomic neuropathy to reduced plasma adrenaline responses to hypoglycemia in IDDM: evidence for a nonselective defect

To determine the contribution of clinically overt diabetic autonomic neuropathy (DAN) to reduced plasma adrenaline responses to hypoglycemia in IDDM and to establish its selectivity for hypoglycemia, we studied 17 IDDM patients (7 without DAN [DAN-] and 10 with DAN [DAN+]), of whom 5 had and 5 did not have postural hypotension (DAN+PH+ and DAN+PH-, respectively), and 8 nondiabetic subjects on 2 different occasions, i.e., clamped hypoglycemia (steps from 5.0 to 2.2 mmol/l plasma glucose) and 30-min steady-state exercise at 55% V(O[2max]). Recent antecedent hypoglycemia was meticulously prevented before the studies to exclude hypoglycemia as a cause of reduced responses of adrenaline to hypoglycemia. In DAN- patients, maximal responses of adrenaline to hypoglycemia were reduced (2.44 +/- 0.58 nmol/l vs. 4.9 +/- 0.54 nmol/l in nondiabetic patients) (P < 0.05). In DAN+, adrenaline responses initiated at a lower plasma glucose and were lower than in DAN- (DAN+PH-, 1.06 +/- 0.38 nmol/l; DAN+PH+, 0.84 +/- 0.27 nmol/l; P < 0.001, but NS between PH- and PH+). In response to exercise, adrenaline increased less in DAN- (0.89 +/- 0.11 nmol/l) patients than in nondiabetic subjects (1.19 +/- 0.14 nmol/l; NS) and only to 0.36 +/- 0.07 nmol/l in DAN+PH- and 0.23 +/- 0.09 nmol/l in DAN+PH+ (P < 0.001 vs. DAN- and nondiabetic subjects). These results were confirmed when nondiabetic and DAN- subjects repeated the exercise at 60 watts (35 and 41% of V(O[2max]), respectively), i.e., at the same absolute workload of DAN+ patients. Thus, DAN (both PH+ and PH-) contributes to reduced responses of adrenaline to hypoglycemia independently of recent antecedent hypoglycemia. The adrenaline defect in DAN is not selective for hypoglycemia.

21-hydroxylase autoantibodies in adult patients with endocrine autoimmune diseases are highly specific for Addison's disease. Belgian Diabetes Registry

The diagnostic specificity of recombinant 21-hydroxylase autoantibodies (21OH-Ab) for Addison's disease was tested in adult patients with either Graves' disease (GD), insulin-dependent diabetes mellitus (IDDM), or polyendocrinopathy, as well as in healthy controls. Using a radiobinding assay with in vitro translated recombinant human 21-hydroxylase, we found 21OH-Ab in 24/28 (86%) idiopathic Addison patients, and using an immunofluorescence assay we found adrenal cortex autoantibodies (ACA) in 12/28 (43%) patients (P = 0.002). All the 12 ACA-positive sera were also positive for 21OH-Ab and ACA were found in 11/15 (73%) patients with less than 15 years and in 1/13 (8%) patients with 15-38 years of disease duration (P = 0.002). 21OH-Ab were present in 3/92 (3%) patients with GD, in 1/180 (0.6%) with IDDM and in 0/106 healthy subjects. The 21OH-Ab-positive GD and IDDM patients were also positive for ACA. None of 17 patients with polyendocrinopathy, but without Addison's disease, had 21OH-Ab. None of the 180 Belgian IDDM patients had Addison' s disease or developed an adrenal insufficiency at follow up. In two out of three Graves patients, the presence of 21OH-Ab was associated with clinical and biochemical signs of adrenal insufficiency. Of the 89 21OH-Ab-negative patients with GD none had Addison's disease at the time of blood sampling, and 79 were followed up for 5.6-7.5 years and none developed clinical signs of adrenal insufficiency. We conclude that the presence of 21OH-Ab in patients with endocrine autoimmune diseases is highly specific for Addison's disease.

Late post-prandial hypoglycaemia as the sole presenting feature of secreting pancreatic beta-cell adenoma in a subtotally gastrectomized patient

In this paper we describe for the first time late post-prandial hypoglycaemia as the sole presenting feature of an insulinoma in a patient who had previously undergone subtotal gastrectomy. The symptoms of hypoglycaemia always occurred 1-3 h after meals, not in the fasting state. Because of the history of gastrectomy and because post-prandial hypoglycaemia was reproduced by an oral glucose tolerance test, the diagnosis of reactive hypoglycaemia was made. Eighteen months later a fasting test was performed: venous plasma glucose decreased from 3.8 mmol/l to 2.7 mmol/l between 14 and 20 h of fast while plasma immunoreactive insulin did not decrease and plateaued at 185 pmol/l. Plasma C-peptide (0.9 nmol/l) and proinsulin (70 pmol/l, split 64, 65) were also elevated. All islet hormones increased in response to i.v. glucose and were suppressed after diazoxide. Although pre-operative procedures were negative in localizing an insulinoma, the patient underwent an operation and an insulinoma was detected at the body level of the pancreas. Thus, insulinoma should be considered in the differential diagnosis of reactive hypoglycaemia in gastrectomized patients. Response of islet hormones to glucose and their suppression by diazoxide are evidence of a secreting insulinoma even in the absence of preoperative localization of the pancreatic adenoma.

Red blood cell ghosts are affected by adrenoleucodystrophy

X-linked adrenoleucodystrophy is a disorder occurring in different clinical forms, characterized by adrenal, gonadal and nervous system dysfunction. The basis of the illness is a derangement of the peroxisomal system necessary to oxidize very long-chain fatty acids that accumulate in various tissues. The diagnosis relies on clinical signs and symptoms and on biochemical findings. The six reported cases presented idiopathic adrenal insufficiency. We measured the lipid composition of red blood cell (RBC) ghosts of patients and control subjects. The distribution of phosphorus among phospholipid classes was unaffected; we could not demonstrate any differences between the fatty acid patterns of RBC membrane, either in total lipid extracts or in separated lipid classes. However, we found an increase in total lipid (both phospholipid and cholesterol), in membrane viscosity and in the Na+/K(+)-dependent ATPase. Therefore, we report four main findings on ghosts in adrenoleucodystrophy patients: (a) very long-chain fatty acids do not accumulate; (b) the lipid-protein ratio increases; (c) fluidity decreases; and (d) the activity of ATPase increases. The last finding is proposed as a possible biochemical marker of the illness. We conclude that adrenoleucodystrophy affects deeply RBC membranes.

Effects of the short-acting insulin analog [Lys(B28),Pro(B29)] on postprandial blood glucose control in IDDM

OBJECTIVE

To establish the effects of the short-acting insulin analog Lispro versus human regular insulin (Hum-R) on postprandial metabolic control in IDDM.

RESEARCH DESIGN AND METHODS

Four studies were performed in 10 C-peptide-negative IDDM patients. Lispro or Hum-R (0.15 U/kg) or Lispro + NPH (0.07 U/kg) or Hum-R + NPH were injected subcutaneously 30 min (Hum-R) or 5 min (Lispro) before lunch. Preprandial plasma glucose (PG) was maintained on all four occasions at approximately 7.3 mmol/l by intravenous insulin.

RESULTS

After subcutaneous Lispro injection, plasma free insulin (FIRI) was greater between 0 and 2 h (233 +/- 22 pmol/l) than after Hum-R (197 +/- 25 pmol/l) but lower between 2.25 and 7 h (81 +/- 10 vs. 104 +/- 13 pmol/l, P < 0.05). After Lispro, PG was lower versus Hum-R for 3 h (7.4 +/- 0.6 vs. 8.3 +/- 0.9 mmol/l) but subsequently increased more than after Hum-R (3.25-7h, 11.3 +/- 1 vs. 9.6 +/- 1.2 mmol/l), resulting in a 7-h postprandial PG greater than Hum-R (9.4 +/- 0.5 vs. 8.8 +/- 0.6 mmol/l) (all P < 0.05). Addition of NPH to Lispro increased the 2.5-to 7-h FIRI to 110 +/- 11 pmol/l and decreased the 3.25- to 7-h PG to 7.7 +/- 0.8 pmol/l, resulting in 0- to 7-h PG (7.3 +/- 0.3 mmol/l) lower than after Hum-R + NPH (7.9 +/- 0.5 pmol/l) (P < 0.05).

CONCLUSIONS

At meals, in order for Lispro to improve postprandial blood glucose not only at 2-h, but also over a 7-h period in C-peptide-negative IDDM, basal insulin must be optimally replaced.

Contribution of amino acids and insulin to protein anabolism during meal absorption

The contribution of dietary amino acids and endogenous hyperinsulinemia to prandial protein anabolism still has not been established. To this end, leucine estimates ([1-14C]leucine infusion, plasma alpha-ketoisocaproic acid [KIC] specific activity [SA] as precursor pool SA) of whole-body protein kinetics and fractional secretory rates (FSRs) of albumin, fibrinogen, antithrombin III, and immunoglobulin G (IgG) were measured in three groups of healthy volunteers during intragastric infusion of water (controls, n = 5), liquid glucose-lipid-amino acid (AA) meal (meal+AA, n = 7), or isocaloric glucose-lipid meal (meal-AA, n = 7) that induced the same insulin response as the meal+AA. The results of this study demonstrate that 1) by increasing (P < 0.01) whole-body protein synthesis and decreasing (P < 0.01) proteolysis, dietary amino acids account for the largest part (approximately 90%) of postprandial protein anabolism; 2) the ingestion of an isocaloric meal deprived of amino acids exerts a modest protein anabolic effect (10% of postprandial protein anabolism) by decreasing amino acid oxidation and increasing (P < 0.01) albumin synthesis; 3) albumin FSR is increased (approximately 20%) by postprandial hyperinsulinemia (meal-AA) and additionally increased (approximately 50%) by amino acid intake (meal+AA); 4) IgG FSR is stimulated (approximately 40%) by amino acids, not by insulin; and 5) fibrinogen and antithrombin III FSR are not regulated by amino acids or insulin.

A rapid qualitative method to assess in vitro immunobarrier competence of pancreatic islets containing alginate/polyaminoacidic microcapsules

A quick method for the qualitative evaluation of immunoisolatory properties associated with islet-containing alginate/poly-L-ornithine (AG/PLO) microcapsules is described. In particular, we examined a new AG/PLO coherent microcapsule (CM) prototype that was recently developed in our laboratory, although the procedure could be applicable to other capsule types as well. We observed no binding of immunoglobulins (Ig) contained in islet cell antibody (ICA)-positive human sera (> 60 Juvenile Diabetes Foundation units, JDT U) to pig islets, enveloped within AG/PLO CM, under indirect immunofluorescence examination. Also, CM were shown to inhibit human lymphocyte proliferative capacity fully, as assessed by the 3H-thymidine incorporation rate, in in vitro mixed xenogeneic pig islet/human lymphocyte co-cultures. These results provided us with a preliminary method to attempt standardization of basic physical/chemical properties which should be associated with an immunoisolatory membrane for islet allo/xenograft immunoprotection.

Absence of circulating adrenal autoantibodies in adult-onset X-linked adrenoleukodystrophy

X-linked adrenoleukodystrophy (ALD) is a frequent cause of adrenal insufficiency in young-adult patients with Addison's disease. As the contribution of an autoimmune process in the destruction of steroid cells in ALD is unclear, the aim of the present study was to evaluate the occurrence of adrenal-, thyroid- and islet-specific and non organ-specific autoantibodies in adult ALD patients. In all 5 patients, Addison's disease was the first manifestation of ALD. None of the ALD patients were positive for adrenal cortex autoantibodies in an indirect immunofluorescence assay, or for 21-hydroxylase autoantibodies in a radiobinding assay with recombinant human antigen. Similarly, we found neither non-organ specific autoantibodies (such as anti-nuclear, anti-ribosomal, anti-mitochondria, anti-smooth-muscle, anti-liver/kidney microsomal or anti-reticulin autoantibodies), nor islet-cell antibodies or glutamic acid decarboxylase (GAD65 or GAD67) autoantibodies, nor thyroglobulin autoantibodies in the sera of the 5 ALD patients. Two out of five patients were positive for thyroid microsomal autoantibodies. One of the two latter thyroid antibody-positive patients had clinical symptoms of hypothyroidism, and the other presented high levels of circulating TSH but no clinical signs or symptoms of hypothyroidism. Our study demonstrates that adult ALD is not immediately associated with the presence of adrenal autoantibodies and suggests that adrenal insufficiency is not mediated by an autoimmune process in adult ALD patients.

Long-term intensive insulin therapy in IDDM: effects on HbA1c, risk for severe and mild hypoglycaemia, status of counterregulation and awareness of hypoglycaemia

The present studies were designed to assess the percentage of HbA1c, frequency, and awareness of hypoglycaemia (H) during long-term intensive therapy (IT) of insulin-dependent diabetes mellitus (IDDM). From 1981 to 1994, 112 IDDM patients were on IT. HbA1c was 7.17 +/- 0.16% (non-diabetic subjects 3.8-5.5%), the frequency of severe H 0.01 +/- 0.009 episodes/patient-year, frequency of mild symptomatic H 35.6 +/- 2.9 episodes/patient-year. IDDM patients with HbA1c < or = 5.5% (Group I, n = 10), between 6.1-7.0% (Group II, n = 12), and > or = 7.6% (Group III, n = 11) were studied to assess responses of counterregulatory hormones, symptoms and cognitive function during experimental, stepped H. Compared to 18 non-diabetic subjects, Group I exhibited high thresholds (plasma glucose had to decrease more than normal to evoke responses), and impaired responses of adrenaline, unawareness of H and delayed onset of cognitive dysfunction at the lowest glycaemic plateau (2.3 mmol/l). Group II had normal thresholds and responses, whereas Group III had low thresholds. Frequency of mild H was higher in Group I (54.5 +/- 1.9 episodes/patient-year) than in Group II and III (33.7 +/- 3.5 and 20.4 +/- 2.5 episodes/patient-year, respectively, p < 0.001) and correlated with percentage of HbA1c (r = -0.82).

IN CONCLUSION

IT can maintain near-normal HbA1c and is compatible with low frequency of severe H. However, if HbA1c is less than 6.0%, mild, symptomatic H is excessively frequent and causes impaired counterregulation and H unawareness. Efforts should be made not only to maintain HbA1c < or = 7.0%, but also to prevent, recognize and reverse iatrogenic H unawareness during long-term IT of IDDM by maintaining HbA1c > 6.0%.

Ultrastructural examination of pancreatic islet containing alginate/polyaminoacidic coherent microcapsules

We ultrastructurally examined pancreatic islet containing alginate/poly-L-ornithine (AG/PLO) coherent microcapsules (CM) which we had previously developed in our laboratory. Specific issues, such as extent of CM coherency as well as morphologic integrity, and viability of the encapsulated islet subcellular organelles were addressed. We preliminarily demonstrated, both at scanning (SEM) and transmission (TEM) electron microscopy analysis, that CM seem to provide for structurally intact and functional, artificial microbarriers, enveloping each individual islet. These findings, additional to CM immunobarrier competence and biocompatibility, previously shown by our studies, might foster progress of CM into islet graft immunoisolation experimental and ultimately clinical trials.

Culture maintenance of isolated adult porcine pancreatic islets in three-dimensional gel matrices: morphologic and functional results

Adult porcine pancreatic islets are attractive for morphological and functional investigations but are difficult to obtain and use. In particular, the islet isolation and purification process is hampered by the lack of an outer capsule membrane, with predisposition to fragmentation. Attempts to culture maintain pig islets and preserve viability and functional competence have also been difficult. We found that placement of isolated porcine islets in biocompatible three-dimensional hydrogel matrices, made of calcium alginate and poly-L-ornithine, would improve morphology, as well as secretory responses to rapid glucose concentration changes.

X-linked adrenoleukodystrophy is a frequent cause of idiopathic Addison's disease in young adult male patients

X-Linked adrenoleukodystrophy (ALD) is a genetic disease associated with demyelination of the central nervous system, adrenal insufficiency, and accumulation of very long chain fatty acids in tissue and body fluids. ALD is due to mutation of a gene located in Xq28 that encodes a peroxisomal transporter protein of unknown function. The most common phenotype of ALD is the cerebral form (45%) that develops in boys between 5-12 yr. Adrenomyeloneuropathy (AMN) involves the spinal cord and peripheral nerves in young adults (35%). Adrenal insufficiency (Addison's disease) is frequently associated with AMN or cerebral ALD and may remain the only clinical expression of ALD (8% of cases). The prevalence of ALD among adults with Addison's disease remains unknown. To evaluate this prevalence, we performed biochemical analysis of very long chain fatty acids in 14 male patients (age ranging from 12-45 yr at diagnosis) previously diagnosed as having primary idiopathic adrenocortical insufficiency. In 5 of 14 patients (35%), elevated plasma concentrations of very long chain fatty acids were detected. None of these patients had adrenocortical antibodies. By electrophysiological tests and magnetic resonance imaging it was determined that two patients had cerebral ALD, one had adrenomyeloneuropathy with cerebral involvement, and two had preclinical AMN. Our data support the hypothesis that ALD is a frequent cause of idiopathic Addison's disease in children and adults.

Method for mass retrieval, morphologic, and functional characterization of adult porcine islets of Langerhans: a potential nonhuman pancreatic tissue resource for xenotransplantation in insulin-dependent diabetes mellitus

BACKGROUND

We aimed to implement and expand an original technique for mass procurement, maintenance, and study of adult porcine pancreatic islets (PPIs), which had been previously developed in our laboratory.

METHODS

By screening through specific criteria for pig donor strain selection, we acquired new leads for separation of large, intact islets from the whole pancreas. Accomplishment of this goal also was permitted by adjusting, and or replacing physical/chemical parameters of the pancreatic digestion process.

RESULTS

High yield isolation and purification of large and intact PPIs was thoroughly associated with full retention of islet morphologic integrity, as proven by accurate assessment of islet cell structure and ultra-structure, as well as viability and functional competence, in vitro and in vivo. In particular, we observed that isolated PPIs may retain capability of synthesizing insulin "de novo," and regulate this property on glucose stimulation. We also began to explore new approaches for in vitro, long-term PPI culture maintenance.

CONCLUSION

We found that a graft of PPI containing algin/polyaminoacidic microcapsules, in nonimmunosuppressed diabetic rodents, was associated preliminary with remission of hyperglycemia, providing further insight into the physiologic competence of these islets.

Liver alcoholic cirrhosis and spur-cell (acanthocytic) anaemia. A study of erythrocyte ghost composition and fluidity

BACKGROUND

The occurrence of spur-cell anaemia in the course of cirrhosis is rare. Alterations of the lipid composition and fluidity of erythrocyte (RBC) ghosts may be present and participate in the phenomenon.

METHODS

A 59-year-old male patient with alcoholic cirrhosis developed severe spur-cell haemolytic anaemia before death. We compared his RBC ghosts with those of 10 cirrhotic patients and used a group of 9 healthy subjects as controls.

RESULTS

The cholesterol to protein ratio was higher in cirrhotic patients; besides, they had less unsaturated fatty acid. The ratio of phospholipid phosphorus to protein did not change; yet, the distribution of phosphorus among phospholipid classes was altered. No difference in 1,6-diphenyl-1,3,5-hexatriene fluorescence anisotropy (membrane fluidity) was observed between the ghosts of cirrhotic patients and those of healthy people. However, the ghosts of the patient with spur-cell anaemia were more rigid than those of either group.

CONCLUSIONS

The values of most variables of cirrhotic patients' ghosts lay between those of healthy subjects and those of the one who developed spur-cell anaemia. It is concluded that some homeostatic mechanisms must control fluidity during cirrhosis; in some cases alterations are particularly great, and fluidity cannot be maintained.

Improved postprandial metabolic control after subcutaneous injection of a short-acting insulin analog in IDDM of short duration with residual pancreatic beta-cell function

OBJECTIVE

To compare postprandial metabolic control after subcutaneous injection of a short-acting insulin analog [Lys(B289),Pro(B29)] (Lispro) or human regular insulin (Humulin R U-100 [Hum-R]) in insulin-dependent diabetes mellitus (IDDM) of short duration with residual beta-cell function.

RESEARCH DESIGN AND METHODS

Six IDDM patients (age 25 +/- 2 years, diabetes duration 14 +/- 2 months, HbA1c 6.4 +/- 0.5%) with residual pancreatic beta-cell function (fasting plasma C-peptide 0.19 +/- 0.02 nmol/l) were studied on three different occasions. Postbreakfast plasma glucose was maintained at approximately 7.1 mmol/l by means of intravenous insulin until either 1200 when 0.1 U/kg Hum-R was injected or until 1225 when 0.1 U/kg of either Hum-R or Lispro was injected subcutaneously. Lunch (mixed meal, 692 Kcal) was served at 1230 (0 min). Six nondiabetic control subjects were also studied.

RESULTS

After Lispro administration, the 120-min plasma glucose decreased more (6.1 +/- 0.3 mmol/l) than after injection of Hum-R at -30 min (7.7 +/- 0.3 mmol/l) or -5 min (9.9 +/- 0.2 mmol/l). By the end of the study, plasma glucose was still lower after Lispro was injected (6.7 +/- 0.3 mmol/l) than after Hum-R was injected at -30 min (7.6 +/- 0.3 mmol/l) or -5 min (7.3 +/- 0.2 mmol/l) (P < 0.05). Two IDDM patients required glucose to prevent hypoglycemia after being injected with Lispro, but four required glucose after being injected with Hum-R at -5 min (Lispro approximately 27 mmol glucose infused between 90 and 240 min; Hum-R approximately 80 mmol between 240 and 390 min). After Lispro, plasma insulin peaked earlier (at 30 min, 342 +/- 29 pmol/l) than after Hum-R injection at -30 min (at 90 min, 198 +/- 28 pmol/l) and was superimposable on that of nondiabetic subjects. In Hum-R injected at -5 min, plasma insulin peaked later (at 120 min) and subsequently remained greater than in the two other studies.

CONCLUSIONS

Despite the lack of a time interval between injection and meal, Lispro controls postprandial plasma glucose concentration better than Hum-R given 30 min before meals and, to an even greater extent, better than Hum-R given 5 min before meals. In addition, Lispro minimizes the risk of postprandial hypoglycemia, thus closely mimicking the postprandial glucose homeostasis of nondiabetic subjects. IDDM patients with residual pancreatic beta-cell function are the ideal candidates for prandial use of Lispro because they can maintain near-normoglycemia longer after subcutaneous analog injection because of residual endogenous insulin secretion.

Hypertension and non-insulin-dependent diabetes. A comparison between an angiotensin-converting enzyme inhibitor and a calcium antagonist

The effects of the angiotensin-converting enzyme lisinopril were compared with those of the calcium antagonist nifedipine in 162 non-insulin-dependent diabetic hypertensive patients for a 24-week period. In 83 and 79 patients, respectively, lisinopril and slow-release nifedipine produced similar reductions in blood pressure (systolic/diastolic: -16/-13 mmHg supine and -14/-11 mmHg standing after lisinopril; -15/-12 mmHg supine and -14/-11 mmHg standing nifedipine). Fasting and post-prandial plasma glucose, glycosylated haemoglobin and plasma lipids appeared to be unaffected by either agent. Also, 28% of the patients on lisinopril and 30% of those on nifedipine presented microalbuminuria. Both drugs induced a reduction in the albumin excretion rate (AER). The geometric mean x:tolerance factor of the reduction in AER among the 23 microalbuminuric patients on lisinopril (-10.0 x:1.3 micrograms/min) was greater, though not significantly so, than that observed in the 26 on nifedipine (-0.9 x 1.2 micrograms/min). Moreover, lisinopril appeared to be better tolerated than nifedipine in our study population. Microalbuminuria is an important risk factor for cardiovascular mortality in non-insulin-dependent diabetic patients as well as in the general population. To what extent a reduction in the AER could ameliorate diabetic patients is, at present, unknown. Finally, both lisinopril and nifedipine showed a similar antihypertensive effect in these patients which was not associated with significant differences in plasma glucose, insulin or lipid concentrations. The clinical consequences of the insignificant differences in AER remain unclear.

High diagnostic accuracy for idiopathic Addison's disease with a sensitive radiobinding assay for autoantibodies against recombinant human 21-hydroxylase

Autoantibodies against 21-hydroxylase (P450c21) are common in idiopathic autoimmune Addison's disease. In the present work, we have developed a sensitive radiobinding assay using in vitro translated recombinant human 35S-P450c21. Levels of P450c21 antibodies (P450c21-Ab) were expressed as a relative index (P450c21 index) using a P450c21-Ab positive Addisonian serum and two antibody-negative healthy sera as positive and negative standards in healthy individuals. The upper level of normal was the mean + 3 SD. Positivity for P450c21-Ab was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of immunoprecipitated 35S-P450c21. In 38 Addisonian patients, P450c21-Ab were found in 24/28 (86%) idiopathic, 0/5 post-tuberculosis, 0/3 adrenoleukodystrophy, and 0/2 post-adrenalectomy sera. Among healthy individuals, 1/70 (1.4%) were positive. The P450c21 index, as an estimate of P450c21-Ab levels, correlated inversely with the duration of idiopathic Addison's disease (r = -0.527; P = 0.007): 16/16 (100%) positive in patients with less than 20 yr and 8/12 (67%) positive in patients with more than 20 yr disease duration. The availability of this simple and sensitive radiobinding assay to evaluate levels of P450c21-Ab will permit large clinical studies as well as screening subjects at risk. In addition, the general population can now be screened to evaluate the predictive value of P450c21-Ab for Addison's disease.

Contribution of obesity to insulin resistance in noninsulin-dependent diabetes mellitus

Inasmuch as previous studies have obtained conflicting results on the contribution of obesity to insulin resistance in noninsulin-dependent diabetes mellitus (NIDDM), we studied 10 nonobese and 10 obese NIDDM patients with the isoglycemic-(approximately 10 mmol/L)-hyperinsulinemic clamp (two insulin infusions of 4 and 40 mU/m-2 min-1), combined with [3-3H]glucose infusion and indirect calorimetry. As compared with nonobese patients, obese NIDDM patients had higher baseline peripheral and estimated portal plasma insulin concentrations (113 +/- 18 vs. 46 +/- 3 pmol/L and 288 +/- 53 vs. 98 +/- 6 pmol/L, respectively; P < 0.05) and less suppressed endogenous insulin production during clamp. Hepatic glucose production was greater in obese than in nonobese patients (basal, 16 +/- 1.1 vs. 12 +/- 0.5 mumol/kg-1 fat-free mass (FFM) min-1; clamp, 5.7 +/- 0.5 vs. 2.8 +/- 0.2 mumol/kg-1 FFM min-1, P < 0.05). Glucose utilization increased to a lesser extent in obese than in nonobese patients (49 +/- 5 vs. 73 +/- 7 mumol/kg-1 FFM min-1, P < 0.05) during clamp because of a lower increase in nonoxidative glucose metabolism (30 +/- 5 vs. 50 +/- 7 mumol/kg-1 FFM min-1, P < 0.05). Plasma free fatty acid concentrations and rates of lipid oxidation were greater in obese (P < 0.05) patients and correlated with hepatic glucose production (r = 0.79 and 0.50, P < 0.05). In conclusion, obesity exaggerates hepatic as well as extra-hepatic insulin resistance in NIDDM. The impaired inhibition of pancreatic beta-cell function by exogenous insulin contributes to exaggerated hyperinsulinemia in obese NIDDM.

Effects of recent, short-term hyperglycemia on responses to hypoglycemia in humans. Relevance to the pathogenesis of hypoglycemia unawareness and hyperglycemia-induced insulin resistance

A single episode of recent hypoglycemia increases, whereas long-term hyperglycemia decreases, the glycemic thresholds of responses of counterregulatory hormone and symptoms to subsequent hypoglycemia in humans. To assess whether short-term, antecedent hyperglycemia exerts effects opposite to those observed after acute hypoglycemia, seven normal, nondiabetic subjects and eight insulin-dependent diabetes mellitus (IDDM) patients were studied during hyperinsulinemic-hypoglycemic clamp (sequential, 90-min plateaus of plasma glucose [PG] of 4.3, 3.7, 3.0, and 2.4 mmol/l). Nondiabetic subjects were studied the morning after either 6-h clamped hyperglycemia (PG approximately 13.5 mmol/l) or euglycemia (PG approximately 5 mmol/l) between 1600 and 2200 the previous day (glucose and insulin infused on both occasions), as well as after nocturnal hyperglycemia (PG approximately 13.5 mmol/l) or euglycemia between 2300 and 0500. The IDDM patients were studied after 15 h of euglycemia or hyperglycemia (approximately 17 mmol/l) but identical hyperinsulinemia (approximately 225 pmol/l) between 1600 and 0700. Neither PG thresholds of counterregulatory hormone, symptoms, onset of cognitive dysfunction to hypoglycemia, nor maximal responses were affected by antecedent, short-term hyperglycemia in normal nondiabetic subjects and IDDM patients (NS). However, the rate of glucose infusion required to maintain hypoglycemic plateaus during hypoglycemia was lower after hyperglycemia (nondiabetic subjects 31.2 +/- 3.4 vs. 36.7 +/- 4 mumol.kg-1.min-1, IDDM patients 33 +/- 3.1 vs. 42.5 +/- 3.9 mumol.kg-1.min-1; P < 0.05) indicating greater insulin resistance induced by antecedent hyperglycemia. In conclusion, in contrast to acute hypoglycemia and long-term hyperglycemia, recent, short-term hyperglycemia does not affect physiological responses to hypoglycemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Ethanol impairs post-prandial hepatic protein metabolism

The effects of acute ethanol ingestion on whole body and hepatic protein metabolism in humans are not known. To simulate social drinking, we compared the effects of the association of a mixed meal (632 kcal, 17% amino acids, 50% glucose, 33% lipids) with a bottle of either table wine (ethanol content 71 g) or water on the estimates ([1-14C]-leucine infusion) of whole body protein breakdown, oxidation, and synthesis, and on the intravascular fractional secretory rates (FSR) of hepatically (albumin, fibrinogen) and extrahepatically (IgG) synthesized plasma proteins in two randomized groups (ethanol n = 7, water n = 7) of healthy nonalcoholic volunteers. Each study was carried out for 8 h. Protein kinetics were measured in the overnight post-absorptive state, over the first 4 h, and during a meal infusion (via a nasogastric feeding tube at constant rate) combined with the oral ingestion of wine or water, over the last 4 h. When compared with water, wine ingestion during the meal reduced (P < 0.03) by 24% the rate of leucine oxidation, did not modify the estimates of whole body protein breakdown and synthesis, reduced (P < 0.01) by approximately 30% the FSR of albumin and fibrinogen, but did not affect IgG FSR. In conclusion, 70 g of ethanol, an amount usual among social drinkers, impairs hepatic protein metabolism. The habitual consumption of such amounts by reducing the synthesis and/or secretion of hepatic proteins might lead to the progressive development of liver injury and to hypoalbuminemia also in the absence of protein malnutrition.

Pharmacokinetics, pharmacodynamics and glucose counterregulation following subcutaneous injection of the monomeric insulin analogue [Lys(B28),Pro(B29)] in IDDM

The aim of these studies was to compare the pharmacokinetics, pharmacodynamics, counterregulatory hormone and symptom responses, as well as cognitive function during hypoglycaemia induced by s.c. injection of 0.15 IU/kg of regular human insulin (HI) and the monomeric insulin analogue [Lys(B28),Pro (B29)] (MI) in insulin-dependent-diabetic (IDDM) subjects. In these studies glucose was infused whenever needed to prevent decreases in plasma glucose below 3 mmol/l. After MI, plasma insulin increased earlier to a peak (60 vs 90 min) which was greater than after HI (294 +/- 24 vs 255 +/- 24 pmol/l), and plasma glucose decreased earlier to a 3 mmol/l plateau (60 vs 120 min) (p < 0.05). The amount of glucose infused to prevent plasma glucose falling below 3 mmol/l was approximately three times greater after MI than HI (293 +/- 26 vs 90 +/- 25 mumol.kg-1 x 60-375 min-1, p < 0.05). After MI, hepatic glucose production was more suppressed (0.7 +/- 1 vs 5.9 +/- 0.54 mumol.kg-1.min-1) and glucose utilization was less suppressed than after HI (11.6 +/- 0.65 vs 9.1 +/- 0.11 mumol.kg-1.min-1) (p < 0.05). Similarly, plasma NEFA, glycerol, and beta-OH-butyrate were more suppressed after MI than HI (p < 0.05), whereas plasma lactate increased only after MI, but not after HI. Responses of counterregulatory hormones, symptoms and deterioration in cognitive function during plasma glucose plateau of 3 mmol/l were superimposable after MI and HI (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute antihyperglycemic mechanisms of metformin in NIDDM. Evidence for suppression of lipid oxidation and hepatic glucose production

To establish the antihyperglycemic mechanisms of metformin in non-insulin-dependent diabetes mellitus (NIDDM) independently of the long-term, aspecific effects of removal of glucotoxicity, 21 NIDDM subjects (14 obese, 7 nonobese) were studied on two separate occasions, with an isoglycemic (plasma glucose approximately 9 mM) hyperinsulinemic (two-step insulin infusion, 2 h each, at the rate of 4 and 40 mU.m-2.min-1) clamp combined with [3-3H]glucose infusion and indirect calorimetry, after administration of either metformin (500 mg per os, at -5 and -1 h before the clamp) or placebo. Compared with placebo, hepatic glucose production (HGP) decreased approximately 30% more after metformin (from 469 +/- 50 to 330 +/- 54 mumol/min), but glucose uptake did not increase. Metformin suppressed free fatty acids (FFAs) by approximately 17% (from 0.42 +/- 0.04 to 0.35 +/- 0.04 mM) and lipid oxidation by approximately 25% (from 4.5 +/- 0.4 to 3.4 +/- 0.4 mumol.kg-1.min-1) and increased glucose oxidation by approximately 16% (from 16.2 +/- 1.4 to 19.3 +/- 1.3 mumol.kg-1.min-1) compared with placebo (P < 0.05), but did not affect nonoxidative glucose metabolism, protein oxidation, or total energy expenditure. Suppression of FFA and lipid oxidation after metformin correlated with suppression of HGP (r = 0.70 and r = 0.51, P < 0.001). The effects of metformin in obese and nonobese subjects were no different. We conclude that the specific, antihyperglycemic effects of metformin in the clinical condition of hyperglycemia in NIDDM are primarily due to suppression of HGP, not stimulation of glucose uptake, and are mediated, at least in part, by suppression of FFA and lipid oxidation.

Chloroquine reduces whole body proteolysis in humans

The antimalaric drug chloroquine is a well known inhibitor of lysosomal proteolysis in vitro. The present study tests the hypothesis that therapeutic doses of the drug decrease proteolysis also in vivo in humans. Leucine kinetics were determined in 20 healthy volunteers given 12 and 1.5 h before the studies 250 and 500 mg, respectively, of chloroquine phosphate (n = 10) or similar tablets of placebo (n = 10). Chloroquine reduced the rates of leucine appearance, a measure of whole body proteolysis, from 2.45 +/- 0.08 to 2.19 +/- 0.08 mumol.kg-1.min-1 (P = 0.038) and those of nonoxidative leucine disposal, an estimate of whole body protein synthesis, from 2.16 +/- 0.08 to 1.95 +/- 0.06 mumol.kg-1.min-1 (P = 0.050). The drug resulted also in a marginally significant (P = 0.051) decrement in the plasma concentrations of glucose. The effects of chloroquine on protein turnover might be potentially useful in counteracting protein wasting complicating several catabolic diseases, whereas those on glucose metabolism can explain the sporadic occurrence of severe hypoglycemic episodes in malaria patients chronically treated with this drug.

Preventive effects of azathioprine (AZA) on the onset of diabetes mellitus in NOD mice

We have studied the effects of long-term treatment with azathioprine (AZA) vs cyclosporin A (CSA) vs placebo (PL), in three groups of 10 week old, prediabetic NOD mice. One of 8 AZA, none of 8 CSA and 7 of 11 PL treated mice developed overt diabetes (IDDM). Quantitative morphometric analysis conducted on mouse pancreatic histologic sections documented that extent and degree of islet beta-cell damage were incomparably less severe in the mice that received AZA or CSA compared to those treated with PL. Since early and prolonged treatment with AZA seems to prevent the onset of DM in NOD mice as nearly effectively as CSA, AZA, which is significantly safer than CSA, could replace the latter as a potential approach for the immunotherapy of IDDM.

Post-hypoglycaemic hyperketonaemia does not contribute to brain metabolism during insulin-induced hypoglycaemia in humans

It is controversial as to whether ketone bodies are utilized by the human brain as a fuel alternative to glucose during hypoglycaemia. To clarify the issue, we studied 10 normal volunteers during an experimental hypoglycaemia closely mimicking the clinical hypoglycaemia of patients with Type 1 (insulin-dependent) diabetes mellitus or insulinoma. Hypoglycaemia was induced by a continuous infusion of insulin (0.40 mU.kg-1.min-1 for 8 h, plasma insulin approximately 180 pmol/l) which decreased the plasma glucose concentration to approximately 3.1 mmol/l during the last 3 h of the studies. Subjects were studied on two occasions, i.e. spontaneous, counterregulatory-induced post-hypoglycaemic increase in 3-beta-hydroxybutyrate (from approximately 0.2 to approximately 1.1 mmol/l at 8 h), or prevention of post-hypoglycaemic hyperketonaemia (plasma beta-hydroxybutyrate approximately 0.1 mmol/l throughout the study) after administration of acipimox, a potent inhibitor of lipolysis. In the latter study, glucose was infused to match the hypoglycaemia observed in the former study. The glycaemic thresholds and overall responses of counterregulatory hormones, symptoms (both autonomic and neuroglycopenic), and deterioration of cognitive function (psychomotor tests) were superimposable in the control study in which ketones increased spontaneously after onset of hypoglycaemic counterregulation, as compared to the study in which ketones were suppressed (p = NS). The fact that responses of counterregulatory hormones, symptoms and deterioration in cognitive function were not exaggerated when posthypoglycaemic hyperketonaemia was prevented, indicate that during hypoglycaemia, the counterregulatory-induced endogenous hyperketonaemia does not provide the human brain with an alternative substrate to glucose. Thus, it is concluded that during hypoglycaemia, endogenous hyperketonaemia does not contribute to brain metabolism and function.