Sergio Ammendola

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We have cloned, sequenced, and overexpressed in Escherichia coli the amidase gene from the hyperthermophilic archaeon Sulfolobus solfataricus (strain MT4). The recombinant thermophilic protein was expressed as a fusion protein with an N-terminus six-histidine-residue affinity tag. The enzyme, the first characterized archaeal amidase, is a monomer of 55,784(More)
OBJECTIVE Our study investigated the metabolic benefits deriving from chronic pharmacological vitamin C administration in aged non-insulin dependent (Type II) diabetic patients. METHODS Forty type II diabetic patients (age: 72 +/- 0.5 years) underwent placebo and vitamin C (0.5 g twice daily) administration in double-blind, randomized, cross-over fashion.(More)
Advancing age has been found to be associated with a decline in insulin action. Nevertheless, no study has been conducted in healthy centenarians. Our study investigates glucose tolerance and insulin action in centenarians. Fifty-two subjects were enrolled. The subjects were divided in three groups as follows: 1) adults (< 50 yr; n = 20);2) aged subjects (>(More)
Melatonin is a modified tryptophan with potent biological activity, exerted by stimulation of specific plasma membrane (MT1/MT2) receptors, by lower affinity intracellular enzymatic targets (quinone reductase, calmodulin), or through its strong anti-oxidant ability. Scattered studies also report a perplexing pro-oxidant activity, showing that melatonin is(More)
It has been demonstrated that healthy centenarians have more favorable anthropometric characteristics and insulin-mediated glucose uptake than aged subjects. The plasma insulin-like-growth factor I (IGF-I) concentration may account for such differences. Three groups of subjects were studied: 1) adults (< 50 yr; n = 30), 2) aged subjects (75-99 yr; n = 30),(More)
Raloxifene (RAL), a selective estrogen receptor modulator, is indicated for the prevention and treatment of postmenopausal osteoporosis. RAL, by decreasing bone turnover, prevents bone loss and microarchitecture damage, reducing the incidence of osteoporotic fractures. Our previous in vitro data demonstrated that RAL modulates osteoclast activity by, at(More)
The signature amidase from the extremophile archeum Sulfolobus solfataricus is an enantioselective enzyme that cleaves S-amides. We report here that this enzyme also converts nitriles in the corresponding organic acid, similarly to the well characterized amidase from Rhodococcus rhodochrous J1. The archaeal and rhodococcal enzymes belong to the signature(More)
Our study investigated body composition and body fat distribution in healthy centenarians. Body composition, body fat distribution, and resting metabolic rate (RMR) were studied in 40 adult subjects aged < 50 y, 35 aged subjects > 75 y, and 15 healthy centenarians aged > 100 y. Body composition was determined by bioimpedance analysis, body fat distribution(More)
Theophylline increases the heart rate in patients with normal sinus rhythm and in patients with sick sinus syndrome. This effect is probably connected to the blockade of adenosine receptors by theophylline. This study evaluated the efficacy of theophylline in 34 elderly patients with symptomatic sinus bradycardia (age 68 +/- 11 years). A resting(More)
The relationship between insulin resistance and aging is still debated. This study aims to investigate the role that age-related differences in plasma dehydroepiandrosterone sulfate (DHEAS) concentration may have on insulin action. For this reason, 75 subjects (42 men and 33 women) with a wide age range (21 to 106 years) were studied. In all subjects,(More)