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Biomedical subjects

C Bizzarri

Publications and source records attributed to C Bizzarri.

At least 19 recordsLinked to original sources

XK-aprosencephaly and related entities.

We offer further biological characterization of the XK atelen/aprosencephaly syndrome in two infants, one with prolonged survival, the other presenting prenatally with apparent hydranencephaly and an orbital tumor (OS). Familial occurrence in the former born to presumably nonconsanguineous Lybian parents may represent parental germinal mosaicism or autosomal recessive inheritance. Both had apparently normal chromosomes; however, the Lybian infant had slightly increased induced chromosome breakage suggesting that this rare multiple congenital anomalies syndrome may involve a DNA repair defect. Virtual absence of atelen/aprosencephalic structures may lead to an arthrogryposis-like prenatal movement disorder. The orbital tumor in the Utah infant consisted of dystopic neural tissue compressing a rudimentary globe and was connected by a thin bridge of neural tissue to the small mass of disorganized brain tissue usually found in atelen/aprosencephalic infants and fetuses. No evidence of an encephaloclastic process was found in the autopsied Utah infant.

Abnormalities, Multiple↗

Plasma levels of adrenomedullin in patients with adrenoleukodystrophy/adrenomyeloneuropathy.

BACKGROUND/AIMS: Adrenomedullin (AM) is a recently purified hypotensive peptide and its encoding gene has been sequenced from a human pheochromocytoma. High levels of AM have been shown in Addison's disease (AD). X-linked adrenoleukodystrophy/adrenomyeloneuropathy (ALD/AMN) is a peculiar adrenal insufficiency due to an accumulation of very-long chain fatty acid in adrenal cells and it is very often associated with a devastating demyelination of the central nervous system. METHODS: We studied the AM plasma levels of 22 patients with ALD/AMN (18 with hypoadrenalism, ALDa, and 4 with normal adrenal function, ALDb) and compared them with 18 males with classical AD and 16 normal male subjects. All patients with hyposurrenalism were studied before treatment with hydrocortisone. RESULTS: Both patients with ALD/AMN and AD showed increased levels of AM and all of them showed a significant difference from the control group (p < 0.0001). The plasma renin activity was higher in all patient groups than in the control group (p <0.001 ALDa, ALDb and AD vs. control group). The aldosterone levels were higher in ALDa and ALDb groups than AD (ALDa vs. AD p < 0.01; ALDb vs. control group p < 0.05; AD vs. controls p < 0.01). ACTH plasma levels were higher in ALDa and AD than ALDb and the control group (ALDa vs. AD not significant while ALDa and AD vs. control p <0.0001). CONCLUSIONS: Our data indicate that plasma AM levels in ALDa, ALDb and AD are higher than controls. These results were previously described in untreated AD. While classical AD patients show complete adrenal insufficiency (both mineralocorticoid and glucocorticoid defects), ALD/AMN patients show a less compromised glomerular function, indicating that AM is not completely correlated with mineralocorticoid insufficiency, and that the exact mechanism responsible for the increased AM levels in ALD/AMN is still unknown.

Addison Disease↗

Targeting C5a: recent advances in drug discovery.

Activation of complement via the innate and adaptive immune system is vital to the body's defences in fighting infections. Unregulated complement activation is likely to play a crucial role in the pathogenesis of several diseases including psoriasis, adult (acute) respiratory distress syndrome (ARDS), bullous pemphigoid (BP), rheumatoid arthritis (RA) and ischemia-reperfusion (I/R) injury. The 74 amino acid peptide C5a is released after complement activation at sites of inflammation and is a potent chemoattractant for neutrophils, basophils, eosinophils, leukocytes, monocytes and macrophages. Recombinant proteins and humanized anti-C5 antibodies have been recently developed for blocking specific proteins of the complement system bringing renewed attention towards complement inhibition. Pharmacological studies have been highlighting the complement fragment C5a as an interesting target for the management of complement mediated diseases. Specific inhibition of C5a biological activity could gain therapeutic benefit without affecting the protective immune response. In the last few years several peptide and non-peptide antagonists of C5a have been discovered and tested in relevant pharmacological models; the availability of orally active compounds is rapidly helping to delineate the precise role of C5a in immunoinflammatory disorders. Moreover, mutagenesis data for the C5a/C5a receptor (C5aR) couple make C5aR a valuable model for mechanistic studies of peptidergic G-protein coupled receptors (GPCRs). The aim of this review is to outline the recent advances in C5a inhibition, especially highlighting the value of a multidisciplinary integrated approach in drug discovery.

Autoimmune Diseases↗

Maintenance of a normal meal-induced decrease in plasma ghrelin levels in children with Prader-Willi syndrome.

Ghrelin is a 28-amino acid peptide recently identified in the stomach as the endogenous ligand for the growth hormone secretagogue receptor (GHS-R1a). Ghrelin is a potent stimulator of GH secretion. It was recently shown that circulating ghrelin levels in humans rise shortly before and fall shortly after every meal, and that ghrelin administration increases voluntary food intake. The hypothesis that ghrelin hypersecretion might contribute to genetic obesity has never been investigated. In this context, Prader-Willi syndrome is the most common form of human syndromic obesity. As ghrelin affects appetite as well as GH secretion and both are abnormal in PWS, it has been surmised that these alterations might be due to ghrelin dysregulation. The aim of the study was to investigate whether ghrelin is suppressed by the meals differently in PWS children than in PWS adults. Overnight circulating fasting ghrelin levels and ghrelin levels 120 min after breakfast were assayed in 7 PWS children (10.2 +/- 1.7 yr), 7 subjects with morbid obesity (10.3 +/- 1.3 yr), and 5 normal controls (8.4 +/- 1.4 yr). Because of the data spread, no statistical difference was observed in fasting ghrelin levels between PWS and control children (p = NS); anyway, fasting ghrelin levels were significantly lower in obese children than in the other groups (p < 0.05 vs. control and PWS children). Ghrelin levels were slightly suppressed by the meal in control subjects (mean fasting ghrelin: 160.2 +/- 82 pg/ml; after the meal, 141.2 +/- 57 pg/ml, p = NS); the meal failed to suppress ghrelin levels in obese children (mean fasting ghrelin: 126.4 +/- 8.5 pg/ml; after the meal, 119.1 +/- 8.3 pg/ml, p = NS). Interestingly, the meal markedly suppressed ghrelin levels in PWS children (mean fasting ghrelin: 229.5 +/- 70.4 pg/ml; after the meal, 155.8 +/- 34.2 pg/ml, p < 0.01). In conclusion, since a lack of decrease in circulating ghrelin induced by the meal was previously reported in PWS adults, the finding of a meal-induced decrease in ghrelin levels in our population of young PWS would imply that the regulation of the ghrelin system involved in the orexigenic effects of the peptide is operative during childhood, although it progressively deteriorates and is absent in adulthood when hyperphagia and obesity progressively worsen.

Adipose Tissue↗

Voiding dysfunction in x-linked adrenoleukodystrophy: symptom score and urodynamic findings.

PURPOSE: Adrenoleukodystrophy is an x-linked genetic disorder characterized by the breakdown of the myelin sheath surrounding nerve cells in the brain and progressive dysfunction of the adrenal gland with 6 possible phenotypes. Lower urinary tract symptoms affect the quality of life of these patients but only sporadic cases have been previously studied by urodynamics. We report to our knowledge the first series in the literature looking at the prevalent pattern. MATERIALS AND METHODS: A total of 14 children and adults 8 to 53 years old (average age 30) with different phenotypes were referred for evaluation. Of the patients 6 had adrenomyeloneuropathy without cerebral involvement (C-) 3 had the adult cerebral form, 3 had the childhood cerebral form, 1 had cerebral involvement (C+) and 1 was asymptomatic. All patients were submitted to a screening protocol, consisting of the self-administered short form questionnaire International Conference on Incontinence Questionnaire-Short Form (ICIQ-SF) and a 3-day voiding diary. Patients were divided in group 1-no urinary symptoms, ICIQ-SF score 0 and no further investigation (3); group 2-frequency/urgency, ICIQ-SF score 1 to 5, uroflowmetry and post-voiding residual urine (4); and group 3-voiding symptoms and incontinence, ICIQ-SF score greater than 5, standard urodynamic examination (7). RESULTS: A neurogenic overactive bladder was the prevalent urodynamic finding (6 of 7 patients), while hypocontractility was found in 1 case. CONCLUSIONS: Vesicosphincteric dysfunction can be explained by spinal and/or cerebral involvement in the different neurological forms of adrenoleukodystrophy. Attempts at treatment with anticholinergics and neuromodulation in 4 of our patients provided temporary benefit with clear subjective amelioration of symptoms and improved quality of life.

Adolescent↗

A randomized trial of nicotinamide and vitamin E in children with recent onset type 1 diabetes (IMDIAB IX).

OBJECTIVE: Various adjuvant therapies have been introduced along with intensive insulin therapy in patients with recent onset type 1 diabetes. Nicotinamide (NA), administered at diagnosis of the disease, can have beneficial effects on the clinical remission rate, improve metabolic control and preserve or slightly increase beta-cell function, probably by reducing toxicity due to free oxygen radicals. Vitamin E, a known antioxidant, inhibits lipid peroxidation; this can lead to protection of islet beta cells from the combined effects of interleukin 1, tumor necrosis factor and gamma interferon. The aim of the present study was to investigate whether the addition of vitamin E to NA could improve metabolic control and the residual beta-cell function, as measured by C-peptide secretion, in children and adolescents with recent onset type 1 diabetes; patients were followed-up for 2 years after diagnosis. PATIENTS AND STUDY DESIGN: Recent onset type 1 diabetes patients (n=64, mean age 8.8 years) were recruited by participating centres of the IMDIAB group. Thirty-two patients were randomized to NA (25 mg/kg body weight) plus vitamin E (15 mg/kg body weight); 32 patients acted as controls and received NA only at the same dose as above. Intensive insulin therapy was applied to both treatment groups. RESULTS: There were three drop outs during the 2-year follow-up period. Overall, patients assigned to the NA+vitamin E group or the NA group did not significantly differ in terms of glycated hemoglobin (HbA1c) levels, insulin requirement or baseline C-peptide secretion. Patients diagnosed at an age of less than 9 years showed significantly reduced C-peptide levels compared with those aged over 9 years at diagnosis and at the 2-year follow-up but there were no differences between the NA and NA+vitamin E treated groups. However at 6 months, patients over 9 years of age treated with NA+vitamin E showed significantly higher C-peptide compared with the NA group (P<0.003). In both age groups and in the different treatment groups, C-peptide levels found at diagnosis were preserved 2 years later. CONCLUSIONS: The use of NA alone, or in combination with vitamin E, along with intensive insulin therapy is able to preserve baseline C-peptide secretion for up to 2 years after diagnosis. This finding is of particular interest for pre-pubertal children with type 1 diabetes and has never been reported before.

Adolescent↗

Selective inhibition of interleukin-8-induced neutrophil chemotaxis by ketoprofen isomers.

Although it is commonly accepted that the anti-inflammatory effect of nonsteroidal anti-inflammatory drugs (NSAIDs) is mainly associated to their ability to inhibit the cyclooxygenase (COX) enzyme system, several results indicate that non-COX mechanisms could be important in the therapeutical effect of these drugs. The aim of this study was to define if NSAIDs could exert, at least in part, their anti-inflammatory effect by inhibiting the activities of human polymorphonuclear leukocytes (PMNs) triggered by chemotactic stimuli and, if so, to understand the relationship of this effect with COX inhibition. A unique opportunity to dissociate the inhibition of prostaglandin (PG) synthesis from other therapeutical properties of NSAIDs is constituted by ketoprofen isomers being the S-isomer 100 time more potent than R-isomer on COX inhibition. Our results show that R- and S-ketoprofen, independently of their potency as PG inhibitors, proved very efficacious in selective inhibition of interleukin-8 (IL-8) chemotaxis. Inhibition of IL-8 chemotaxis was not restricted to ketoprofen isomer as it could be observed also with drugs belonging to different classes of NSAIDs and it was obtained at drug concentration superimposable to plasma levels after therapeutic administration in patients. Reduction of IL-8 migration by ketoprofen isomers was paralleled by selective inhibition of PMN response in terms of intracellular calcium concentration ([Ca(2+)]i) increase and extracellular signal regulated kinase(ERK)-2 activation, two intracellular mediators reported to be critical for PMN activities. It is concluded that inhibition of IL-8 chemotaxis could represent a new clinical target for ketoprofen isomers and, in fact, contribute to the anti-inflammatory activity of NSAIDs.

Calcium↗

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↗

Neuroregulation of growth hormone during exercise in children.

Physical exercise is an important physiological stimulus to growth hormone (GH) release in man. Many neurotransmitters are involved in GH regulation. We studied the effect of the cholinergic pathway on GH secretion induced by physical exercise. Particularly, we studied the effect of a cholinergic muscarinic agonist on GH-induced physical exercise, both in children and adults. Moreover, we investigated the refractoriness of GH secretion after a second physical exercise stimulus. Three different protocols were performed: 1) GH response to physical exercise in children and adults; 2) effect of pyridostigmine on exercise-induced GH secretion in children and adults; 3) GH response to two consecutive exercises in children and adults. Our data show that in children GH peak after physical exercise is higher than in adults. Pyridostigmine enhances GH release in children and in adults. Exercise stimulus was able to release GH in the second test only in children, while the refractory phase did not permit a new GH release in adults. The shift to a modality of neural control of GH secretion peculiar of adults is likely due to neuroregulatory mechanisms which may be partly dependent on long-term variation in hormonal milieu.

Adolescent↗

Characterization and properties of dominant-negative mutants of the ras-specific guanine nucleotide exchange factor CDC25(Mm).

Ras proteins are small GTPases playing a pivotal role in cell proliferation and differentiation. Their activation depends on the competing action of GTPase activating proteins and guanine nucleotide exchange factors (GEF). The properties of two dominant-negative mutants within the catalytic domains of the ras-specific GEF, CDC25(Mm), are described. In vitro, the mutant GEF(W1056E) and GEF(T1184E) proteins are catalytically inactive, are able to efficiently displace wild-type GEF from p21(ras), and strongly reduce affinity of the nucleotide-free ras x GEF complex for the incoming nucleotide, thus resulting in the formation of a stable ras.GEF binary complex. Consistent with their in vitro properties, the two mutant GEFs bring about a dramatic reduction in ras-dependent fos-luciferase activity in mouse fibroblasts. The stable ectopic expression of the GEF(W1056E) mutant in smooth muscle cells effectively reduced growth rate and DNA synthesis with no detectable morphological changes.

Animals↗

Thioredoxin, a redox enzyme released in infection and inflammation, is a unique chemoattractant for neutrophils, monocytes, and T cells.

Thioredoxin (Trx) is a ubiquitous intracellular protein disulfide oxidoreductase with a CXXC active site that can be released by various cell types upon activation. We show here that Trx is chemotactic for monocytes, polymorphonuclear leukocytes, and T lymphocytes, both in vitro in the standard micro Boyden chamber migration assay and in vivo in the mouse air pouch model. The potency of the chemotactic action of Trx for all leukocyte populations is in the nanomolar range, comparable with that of known chemokines. However, Trx does not increase intracellular Ca2+ and its activity is not inhibited by pertussis toxin. Thus, the chemotactic action of Trx differs from that of known chemokines in that it is G protein independent. Mutation of the active site cysteines resulted in loss of chemotactic activity, suggesting that the latter is mediated by the enzyme activity of Trx. Trx also accounted for part of the chemotactic activity released by human T lymphotropic virus (HTLV)-1-infected cells, which was inhibited by incubation with anti-Trx antibody. Since Trx production is induced by oxidants, it represents a link between oxidative stress and inflammation that is of particular interest because circulating Trx levels are elevated in inflammatory diseases and HIV infection.

Animals↗

Somatostatin infusion withdrawal: studies in normal children and in children with growth hormone deficiency.

Withdrawal of a somatostatin infusion (SSIW) is followed by a rebound rise of GH in both animals and normal adult men, a phenomenon likely mediated by endogenous GHRH function. In the present study, we have evaluated the GH response to SSIW in a group of 28 prepubertal children (18 boys and 10 girls; aged 3.7-11.1 yr). Six children had GH deficiency [GHD; GH responses to pyridostigmine (PD)+GHRH and to clonidine <20 and <7 microg/L, respectively], 4 children had GH neurosecretory dysfunction (GHND; GH responses to PD+GHRH and to clonidine > or =20 and >7 microg/L, respectively; mean integrated nighttime GH concentrations <3 microg/L), and 18 children were short normal children [normal controls (NC)]. All children received a constant infusion of SS at the dose of 3 microg/Kg x h for 90 min. SSIW elicited a clear-cut GH rise in NC children (13.7+/-1.0 microg/L), but not in GH-deficient children, regardless of the underlying etiology (GHD, 1.6+/-0.4 microg/L; GHND, 2.4+/-0.3 microg/L). The GH response to SSIW was similar between GHD and GHND children. There was no overlapping of the maximum SSIW-stimulated GH peaks between NC and GHD or GHND children. In conclusion, we have demonstrated that SSIW elicits a significant GH rise in NC children, but not in GH-deficient children, regardless of the underlying etiology (GHD or GHND). This resulted in complete discrimination of NC from GHD or GHND children. Were these present findings confirmed on a larger number of children, SSIW, because of its testing efficaciousness and safety, procedural simplicity, and economy holds promise of being a useful diagnostic tool for GH-dependent growth disorders.

Adrenergic alpha-Agonists↗

T-cell mediated autoimmunity to the insulinoma-associated protein 2 islet tyrosine phosphatase in type 1 diabetes mellitus.

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.

Adolescent↗

Prognostic implications of hyperglycaemia in paediatric head injury.

Fifty children with head injury were evaluated in an attempt to establish a correlation between post-traumatic hyperglycaemia and long-term outcome. In all the patients, the blood glucose level was measured on admission and on the days following the trauma (threshold of normal value set at 150 mg/dl). Hyperglycaemia was seen more frequently in children with severe head injury than in those with mild and moderate head injury. It was present in 87.5% of the patients with a Glasgow Coma Score (GCS) < or =8 (the average blood glucose level on admission was 237.8+/-92 mg/dl), in 60% of the patients with a GCS of 9-12 (178+/-78.7 mg/dl) and only in 25% of those with a GCS of 13-15 (131.5+/-39 mg/dl). A close correlation was also seen between the outcome and the blood glucose level. In fact, the blood glucose on admission was higher in the patients with a poor outcome, i.e. in those having a Glasgow Outcome Score (GOS) of 2 or 3 and in those who died (GOS 1), than in the patients with a good outcome (GOS of 4 or 5). Finally, hyperglycaemia persisted beyond the first 24 h after trauma in all the children who died or who survived with a poor outcome. Hyperglycaemia, and especially its persistence over time, appears to be an important negative prognostic factor in children with head injury.

Adolescent↗

Inhibitory activity of IL-1 receptor antagonist depends on the balance between binding capacity for IL-1 receptor type 1 and IL-1 receptor type II.

A series of mutants of human IL-1 receptor antagonist (IL-1ra) has been designed by comparison of IL-1ra and IL-1beta structures in order to increase receptor antagonist capacity. Upon in vitro and in vivo assay of IL-1 antagonism, the IL-1ra mutants DoB 0039 (N91-->R), DoB 0040 (T109-->A) and DoB 0041 (N91/T109-->R/A) could inhibit IL-1beta effects more efficiently than wild-type IL-1ra, with DoB 0041 being the most active. Analysis of the receptor-binding capacity of the IL-1ra mutants showed that all three mutants could inhibit binding of IL-1alpha or IL-1beta to IL-1RI-bearing cells more efficiently than wild-type IL-1ra. Conversely, binding of IL-1beta to IL-1RII-bearing cells could be inhibited by DoB 0041 much less efficiently than by wild-type IL-1ra. It is known that the two types of IL-1 receptors (IL-1RI and IL-1RII) play different roles in the regulation of IL-1 activity, with IL-1RI being solely responsible for cell triggering upon IL-1 binding, whereas IL-1RII acts as a scavenger of IL-1 and can thus be considered as a natural IL-1 inhibitor. Thus, the enhanced inhibitory capacity of DoB 0041 as compared with wild-type IL-1ra is explained in terms of better binding to the activating receptor IL-1RI and poorer interaction with the inhibitory receptor IL-1RII.

Animals↗

Incidence of insulin-dependent diabetes mellitus among Sardinian-heritage children born in Lazio region, Italy.

BACKGROUND: The relative importance of genetic and environmental factors in causing insulin-dependent diabetes mellitus (IDDM) is unknown. We studied this question by assessing the incidence of the disease in children, born in a region with a low incidence of IDDM (Lazio), but whose parents came from a region with high incidence (Sardinia). METHODS: We identified all IDDM cases that occurred between 1989 and 1994. We used as the denominator the number of children aged 0-14 born in Lazio of Sardinian parents to calculate incidence. We compared this rate with the incidences of IDDM in the populations of Lazio and Sardinia. FINDINGS: The age-adjusted incidence of IDDM in Sardinian-heritage children born and living in Lazio was 33.8 per 100,000 per year (95% CI 7.0-99.0) for those with two Sardinian parents, and 15.9 (8.7-26.6) for those with only one parent from Sardinia. The former incidence was not different from that recorded in Sardinia (34.4, 31.3-37.9), but was fourtold that of Lazio-heritage children (7.9, 7.1-8.8). INTERPRETATION: Our results show that two different ethnic groups living in the same region have a fourfold difference in incidence of IDDM. Children of Sardinian-heritage born in Lazio have the same incidence as the population of origin, which is genetically prone to the disease. Moreover, children with one Sardinian parent had a rate half that of Sardinians and double that of the indigenous population. We conclude that in a given population genetic susceptibility determines the frequency of IDDM in response to the environmental challenge.

Adolescent↗

Purification of human recombinant interleukin 1 receptor antagonist proteins upon Bacillus subtilis sporulation.

Human interleukin 1 receptor antagonist (IL-1ra) and IL-1ra mutants were constitutively expressed in recombinant Bacillus subtilis in endocellular and active form. In order to optimize the purification of the recombinant proteins, a new method has been developed. After bacterial growth in fermenter, release of recombinant protein was achieved by starvation-induced sporulation. The sporulation supernatant was recovered by centrifugation, filtered, and subjected sequentially to cation- and anion-exchange chromatography. Alternatively, the fermenter's contents were directly subjected to expanded bed adsorption on a Streamline cation-exchange column, thus avoiding the centrifugation and filtration steps. Up to 88 mg of biological active purified recombinant protein per liter of culture was obtained, with a 72-79% recovery and 98% purity, depending on the molecule. By using the method described here, it is possible to achieve a spontaneous release of recombinant proteins expressed endocellularly at high levels in B. subtilis without need of a cell breakage step. Thus, this method could allow purification of the endocellular recombinant protein as if it were secreted. Furthermore, when using the expanded bed adsorption, highly purified protein was obtained in only two steps after sporulation. Among the advantages of the method, one of the most relevant is the possibility of keeping the system closed up to completion of the first purification step.

Bacillus subtilis↗