Stefano Laureti

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

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.

Steroid-cell autoantibodies are preferentially expressed in women with premature ovarian failure who have adrenal autoimmunity.

OBJECTIVE To determine the prevalence of steroid-cell autoantibodies, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) antibodies, 17alpha-hydroxylase (17alpha-OH) antibodies, and P450 side-chain cleavage antibodies in premature ovarian failure. DESIGN Cross-sectional, observational study. SETTING Academic research hospitals. PATIENT(S) Eighty-one women with premature ovarian failure, 20 women with Addison disease not associated with premature ovarian failure, 42 women with type 1 diabetes mellitus, and 90 healthy women. MAIN OUTCOME MEASURE(S) Serum levels of steroid-cell autoantibodies, 17alpha-OH antibodies, P450 side-chain cleavage antibodies, and 3beta-HSD antibodies. RESULT(S) Steroid-cell autoantibodies were present in none of 57 women with isolated premature ovarian failure or premature ovarian failure plus nonadrenal autoimmune disease and in 21 of 24 (87%) women with Addison disease-related premature ovarian failure. 17alpha-Hydroxylase antibodies and P450 side-chain cleavage antibodies were significantly more frequent in women positive for adrenal autoantibodies than in those negative for adrenal autoantibodies (50% vs. 0% and 71% vs. 2%, respectively). The presence of 17alpha-OH antibodies or P450 side-chain cleavage antibodies was strongly associated with presence of steroid-cell autoantibodies. Two of 24 (8%) women with Addison disease-related premature ovarian failure and 1 of 57 (2%) women with isolated premature ovarian failure or premature ovarian failure plus nonadrenal autoimmune disease were positive for 3beta-HSD antibodies. None of 20 adult women with autoimmune Addison disease and none of 42 adult women with type 1 diabetes mellitus not associated with premature ovarian failure was positive for 3beta-HSD antibodies. CONCLUSION(S) Markers of steroid-cell autoimmunity are found only rarely in idiopathic premature ovarian failure not associated with Addison disease. Most women with Addison disease-related premature ovarian failure were positive for steroid-cell autoantibodies, 17alpha-OH antibodies, or P450 side-chain cleavage antibodies. 3beta-Hydroxysteroid dehydrogenase antibodies do not appear to be a major marker of steroid-cell autoimmunity.

Autoantibodies in autoimmune polyendocrine syndrome type II

The autoimmune polyendocrine syndrome type II (APS-II) is characterized by the association of autoimmune Addisons disease with thyroid autoimmune diseases or type-1 diabetes mellitus. 21-Hydroxylase autoantibodies enable the accurate diagnosis of autoimmune Addisons disease and, in patients with other endocrine autoimmune diseases, identify subjects at high risk for clinical adrenal insufficiency. 17 alpha-Hydroxylase (17OH) and side-chain-cleavage enzyme (P450scc) are target autoantigens of steroid-cell autoantibodies, and in women with Addisons disease, 17OH autoantibodies and P450scc autoantibodies are markers of increased risk for premature ovarian failure. Thyroperoxidase autoantibodies, thyroglobulin autoantibodies, H+/K(+)-ATPase autoantibodies, and GAD65 autoantibodies are frequently detected in patients with isolated Addisons or APS-II. Screening for other organ-specific autoimmune diseases should be performed in every patient with at least one major disease component of APS-II.

Coded waveforms for optimised air-coupled ultrasonic nondestructive evaluation

This paper investigates various types of coded waveforms that could be used for air-coupled ultrasound, using a pulse compression approach to signal processing. These are needed because of the low signal-to-noise ratios that are found in many air-coupled ultrasonic nondestructive evaluation measurements, due to the large acoustic mismatch between air and many solid materials. The various waveforms, including both swept-frequency signals and those with binary modulation, are described, and their performance in the presence of noise is compared. It is shown that the optimum choice of modulation signal depends on the bandwidth available and the type of measurement being made.

Low dose (1 μg) ACTH test in the evaluation of adrenal dysfunction in pre‐clinical Addison's disease

The presence of 21‐hydroxylase autoantibodies (21OHAb) is a marker of adrenal autoimmunity and can be used to identify subjects with pre‐clinical Addisons disease. The low‐dose (1 μg) ACTH test (LDT) is more sensitive than the high‐dose (250 μg) test (HDT) for the diagnosis of pituitary adrenal insufficiency, but no information is available on the use of a LDT in subjects with autoimmune adrenalitis and primary adrenal insufficiency. The aim of our study was to evaluate the clinical use of the LDT in the diagnosis of early adrenocortical dysfunction in patients with adrenal autoantibodies.

Administration of recombinant human growth hormone on alternate days is sufficient to increase whole body protein synthesis and lipolysis in growth hormone deficient adults

At present, the duration of the effect of recombinant human growth hormone (rhGH) on the rates of protein synthesis and lipolysis in GH deficient (GHD) adults is unknown. This study was designed to establish the frequency of rhGH administration necessary to provide the beneficial metabolic effects of the hormone in GHD adults.

Improvement of treatment of primary adrenal insufficiency by administration of cortisone acetate in three daily doses

In the present study, we compared the effects of 3 daily administrations of cortisone acetate vs a classical regimen with 2 daily administrations, in patients with primary adrenal insufficiency (PAI). We enrolled 34 patients with PAI treated with 2 daily doses of cortisone acetate (2/3 of the total daily dose early in the morning, 1/3 in the afternoon) who were subdivided into two groups: group A (no.=18; 4 males, 14 females; age: median 55 yr, range 24–88) continued with the standard 2 daily administrations, group B (no.=16; 8 males, 8 females; age: median 44 yr, range 27–70) switched to 3 daily administrations (3/6 of the daily dose early in the morning, 2/6 after lunch, 1/6 after dinner), but without any change of the total daily dose. After 6 months of therapy, basal and 90-min post-cortisone acetate ACTH levels in group B (219 pg/ml, range 19.9–1197, and 84 pg/ml, range 14.4–480, respectively) were significantly lower than those observed at the beginning of the study (482 pg/ml, range 58–1900 and 215 pg/ml, range 52–1832, respectively; p=0.001 and p=0.027, respectively). No statistically significant differences were observed in group A. Similarly, 24-h urinary cortisol (UFC) excretion increased significantly after 6 months of a 3-dose therapy in group B (from 74.6 μg/24 h, range 24–148, to 98.8 μg/24 h, range 48–214; p=0.006), but not in group A (p=ns). Moreover, UFC excretion after 6 months of a 3-dose therapy was significantly higher than after 6 months of a 2-dose therapy (98.8 μg/24 h, range 48–214 vs 49.8 μg/24 h, range 11–183, p=0.032). No significant variations of basal and 90-min post-cortisone levels of cortisol were observed in either group. Our study demonstrates that the subdivision of the total daily dose of cortisone acetate in 3 administrations increases total UFC excretion and reduces plasma ACTH levels, thus improving the substitutive therapy.

Dehydroepiandrosterone, 17alpha-hydroxyprogesterone and aldosterone responses to the low-dose (1 micro g) ACTH test in subjects with preclinical adrenal autoimmunity.

objective The appearance of 21‐hydroxylase autoantibodies (21OHAbs) identifies subjects with preclinical adrenal insufficiency. In 21OHAb‐positive subjects, the adrenocortical function is best evaluated by peak cortisol (F) levels after the low‐dose (1 µg) ACTH stimulation test (LDT). No information is currently available on the correlation between F and other adrenocortical hormone responses to the LDT in subjects with an ongoing autoimmune adrenal process. In this study, we tested the hypothesis that the dehydroepiandrosterone (DHEA), 17α‐hydroxyprogesterone (17OHP) and aldosterone (A) responses to the LDT are consensual to that of F during the preclinical phase of autoimmune adrenal insufficiency.

Ultrasonic NDE of thick polyurethane flexible riser stiffener material

Abstract Ultrasonic signals at frequencies below 1 MHz have been used for the NDE of thick polymer samples. Coded signals such as chirps and bipolar Golay codes, together with pulse compression and signal processing, have been used to penetrate into thick sections of attenuating polypropylene riser stiffener material, using piezocomposite transducers to provide the required bandwidth. It is shown that this approach can be used to detect manufacturing defects such as air bubbles in flexible riser stiffeners, which might compromise their performance in the offshore oil and gas environments.

High-resolution acoustic imaging at low frequencies using 3D-printed metamaterials

An acoustic metamaterial has been constructed using 3D printing. It contained an array of air-filled channels, whose size and shape could be varied within the design and manufacture process. In this paper we analyze both numerically and experimentally the properties of this polymer metamaterial structure, and demonstrate its use for the imaging of a sample with sub-wavelength dimensions in the audible frequency range.